WO2020041248A1 - Balle de recyclage comprenant un ester de cellulose - Google Patents

Balle de recyclage comprenant un ester de cellulose Download PDF

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Publication number
WO2020041248A1
WO2020041248A1 PCT/US2019/047170 US2019047170W WO2020041248A1 WO 2020041248 A1 WO2020041248 A1 WO 2020041248A1 US 2019047170 W US2019047170 W US 2019047170W WO 2020041248 A1 WO2020041248 A1 WO 2020041248A1
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WO
WIPO (PCT)
Prior art keywords
fibers
bale
staple fibers
cellulose
composition
Prior art date
Application number
PCT/US2019/047170
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English (en)
Inventor
Charles Stuart EVERETT
Melvin Glenn Mitchell
Kenny Randolph Parker
Original Assignee
Eastman Chemical Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US16/522,961 external-priority patent/US11286619B2/en
Priority claimed from US16/522,956 external-priority patent/US11230811B2/en
Application filed by Eastman Chemical Company filed Critical Eastman Chemical Company
Publication of WO2020041248A1 publication Critical patent/WO2020041248A1/fr

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Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
    • D21H13/02—Synthetic cellulose fibres
    • D21H13/06—Cellulose esters
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C5/00—Other processes for obtaining cellulose, e.g. cooking cotton linters ; Processes characterised by the choice of cellulose-containing starting materials
    • D21C5/02—Working-up waste paper
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H15/00—Pulp or paper, comprising fibres or web-forming material characterised by features other than their chemical constitution
    • D21H15/02—Pulp or paper, comprising fibres or web-forming material characterised by features other than their chemical constitution characterised by configuration
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H15/00—Pulp or paper, comprising fibres or web-forming material characterised by features other than their chemical constitution
    • D21H15/02—Pulp or paper, comprising fibres or web-forming material characterised by features other than their chemical constitution characterised by configuration
    • D21H15/04—Pulp or paper, comprising fibres or web-forming material characterised by features other than their chemical constitution characterised by configuration crimped, kinked, curled or twisted fibres
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/64—Paper recycling

Definitions

  • the present invention relates bales of CE staple fibers fed to a hydropulper to make wet laid products.
  • Wet laid products are generally made by a process in which a stock, or furnish, is prepared by suspending pulped cellulose fibers in water and refining this mixture to prepare a refined pulp slurry or pulp stock containing fibrillated cellulose fibers, and optionally adding one or more of a variety of additives such as retention aids, internal sizing agents, strength polymers and fillers as needed to satisfy end use requirements.
  • the stock is then deposited onto the forming section of a wet laid machine, such as a paper machine, to make a wet laid web.
  • the wet tensile strength of the wet laid web at the forming section may drop so far that the web may become difficult to process because it cannot support its own weight. It would be desirable to be able to feed a hydropulper, that is in fluid communication with a refiner, with a synthetic fiber that can be refined, thereby avoiding the need to by-pass the refiner using separate added equipment to feed the refined cellulose with a synthetic fiber downstream of the refiner. It would also be desirably to feed a hydropulper the same way that it is being fed with cellulose fibers; that is, by dropping bales of fiber into the hydropulper.
  • Recycle mills have an additional process step of flotation and de-inking.
  • the waste/recycle mills furnish bales of dried pulp to a wet laid facility, and the waste/recycle pulp is either added to a hydropulper and eventually fed to a refiner, or it is fed to a blend tank downstream of the refiner.
  • the waste/recycle cellulose fibers have already been fibrillated in the course of their manufacture from virgin cellulose fiber.
  • bale comprising sheets, wherein at least one of the sheets in the bale comprises waste/recycle cellulose fibers and cellulose ester (CE) staple fibers, wherein said CE staple fibers have:
  • DPF denier per filament
  • bales to a hydropulper comprising feeding a CE containing bale to a hydropulper, or a blend tank directly or indirectly in fluid communication with a hydropulper, wherein at least one of said sheets comprises waste/recycle cellulose fibers and cellulose ester (CE) staple fibers, said CE staple fibers having:
  • DPF denier per filament
  • bale of sheets in which at least one of the sheets contains waste/recycle cellulose fibers and cellulose ester (CE) staple fibers, to feed a hydropulper or a blend tank directly in indirectly in fluid communication with a hydropulper for making wet laid products, wherein the CE staple fibers have
  • DPF denier per filament
  • Figure 1 is a block flow diagram of a wet laid process for making wet laid webs.
  • Figure 2 is a block flow diagram of a stock preparation process.
  • Figure 3 is a block flow diagram of a wet laid machine process.
  • Figure 4 is a diagram of crimps applied to a fiber describing the basis for calculating the crimp amplitude and crimp ratio.
  • Figure 5 is a diagrammatic example of the basis for measuring dry line movement on the wire.
  • Figure 6 is a temperature profile adjustment that can be made in a drying zone by using the Composition in the web.
  • Figure 7 is an example of the approach flow for controlling the consistency of pulp to a headbox from a machine chest.
  • Figures 8-39 and 41 -49 illustrate in bar chart format the data set from the tables under each corresponding example.
  • Figure 40 illustrates a Williams Slowness Drainage apparatus.
  • compositions containing cellulose fibers and synthetic cellulose fibers comprising cellulose ester staple fibers, wherein the cellulose ester fibers have one or a combination of the following features: a denier per filament (DPF) of less than 3.0, a cut length of less than 6 mm, a non-round shape, and/or crimped (used throughout as“Composition”).
  • DPF denier per filament
  • the Compositions as used throughout this description can be present at any one or more process steps or zones, or in any one or more vessels or pipes, in a stock preparation process or a wet laid machine process, as well as in any wet laid articles.
  • the Compositions can be present as feeds to, within, or as effluents from a hydropulper, any blending vessel, a refiner, a machine chest, a stuff box, a hydrocyclone, a pressure screen, the basis weight valve, fan pumps, in the headbox, on the wire, in the presses, dryers, sizing press, as sheets on rolls, in a broke vessel, in a calender, or as consumer articles, and any steps in between.
  • the wet laid articles can contain and be obtained from the Compositions and can be formulated with the Compositions.
  • the Compositions contain cellulose fibers and cellulose ester fibers at least a portion of which are cellulose ester staple fibers (“CE staple fibers”).
  • the cellulose fibers are fibers obtained from plant- based sources of cellulose that have not been further chemically derivatized with functional groups.
  • Cellulose fibers can be virgin or from waste/recycle sources.
  • the CE staple fibers and filaments made therefrom are synthetic fibers that are derivatives of cellulose obtained by a synthetic process
  • A“100% Cellulose Comparative composition” is a composition in which the fiber component is 100% cellulose fibers and is in all other respects the same as a reference Composition, including consistency, cellulose fiber type, formulation ingredients and quantities, stock preparation process conditions, and refining conditions, and any other applicable conditions, unless a condition is specifically expressed as a difference.
  • the 100% Cellulose Comparative Composition would also be a sheet or wet laid product; or if the reference is to a composition containing waste/recycle and virgin cellulose fibers, to be the same in all respects the
  • Cellulose Comparative Composition would also contain the same proportion of waste/recycle cellulose fibers to virgin cellulose fibers.
  • A“cellulose fiber” can include virgin or waste/recycle fibers, and can be fibrillated or non-fibrillated.
  • Co-refining or“Co-refined” means that at least a cellulose fiber and a CE staple fiber are refined in the presence of each other, and cellulose fibers and CE staple fibers present in a feed stream to a refiner are deemed to be co-refined.
  • a co-refined cellulose fiber means that the cellulose fiber is refined in the presence of a CE staple fiber
  • a co-refined CE staple fiber means a CE staple fiber that has been co-refined in the presence of a cellulose fiber.
  • The“consistency” is a measure of the solids concentration in a liquid stream, and can be determined drying a representative sample of the liquid stream and dividing the weight of the oven dried solids to the weight of the representative sample.
  • A“machine direction” or“MD” is the direction the web moves on a wet laid machine or with respect to wet laid articles, the direction on the article corresponding to the direction the article moved on a wet laid machine.
  • the “cross direction” or“CD” means the direction crossing or perpendicular to the MD of the web or sheet.
  • A“non-woven web” is a web made from fibers without weaving or knitting operations.
  • A“Post-Addition” or“Post-Addition Composition” is a combination of fibrillated or refined cellulose fibers and CE staple fibers in which the CE staple fibers have not been co-refined with the cellulose fibers and the CE staple fibers are combined with the cellulose fibers only after the cellulose fibers have been refined and the cellulose fibers are not further refined.
  • CE staple fibers are deemed not to have been co-refined with cellulose fibers if the feed to the refiner does not contain CE staple fibers.
  • the Post Addition Composition is identical to a reference Composition, except that the CE staple fibers are not present during refining and are combined with cellulose fibers only after the cellulose fibers are refined.
  • the cellulose fibers in the Post Addition Composition are refined under the same process conditions as the reference Composition, and the consistency of the cellulose fiber furnish fed to the refiner is the same as the consistency of the reference Composition feed to the refiner.
  • the CE staple fibers are added to the refined cellulose furnish and the consistency of the blend is adjusted to have the same consistency as the reference Composition.
  • Post-Addition CE staple fibers are CE staple fibers added to cellulose fibers after the cellulose fibers have been refined without any further refining of the cellulose fibers.
  • A“thick stock” has a solids content (or stock consistency) of at least
  • A“thin stock” has a solids content (or stock consistency) of less than 2.0 wt.%.
  • the term“virgin” means stock or fibers that have not been used for their intended end use, provided that the fibers, when contained in a wet laid web or other article, have not yet been inked or de-inked.
  • A“wet laid non-woven product” is a product in which at least 50 wt.% of the fibers have an L/D of more than 300.
  • A“wet laid process” is a process in which fibers dispersed in a liquid, such as water, at any consistency, are deposited onto a wire, drying matt, or filter on which the liquid is drained or removed to form a web that is either dried or thermally bonded.
  • a wet laid process can be distinguished from a dry laid process which employs air-laid, carding techniques, or needlepunch techniques.
  • A“wet laid product” or“wet laid web” is a product made by a wet laid process, and can include non-woven products, and can also include paper-like products in which at least 50 wt.% of the fibers have an L/D of 300 or less.
  • cellulose fibers are obtained from a source of cellulose.
  • the term cellulose is meant to include the unbranched polymer of D-glucose (anhydroglucose) obtained from a plant source.
  • Cellulose and the cellulosic fibers include at least one polymer of unbranched D-glucose and can optionally also include hemicellulose and/or lignin.
  • Individual cellulose polymer chains associate to form thicker microfibrils which, in turn, associate to form fibrils which are arranged into bundles. The bundles form fibers which are visible as components of the plant cell wall when viewed at high magnification under a light microscope or scanning electron microscope.
  • hemicellulose refers to a heterogeneous group of low molecular weight carbohydrate polymers that are associated with cellulose in wood. Hemicelluloses are generally branched polymers, in contrast to cellulose which is a linear polymer. The principal, simple sugars that combine to form hemicelluloses are: D-glucose, D-xylose, D-mannose, L-arabinose, D-galactose, D-glucuronic acid and D-galacturonic acid.
  • Lignin is a complex aromatic polymer and comprises about 20% to
  • Lignins can be grouped into three broad classes, including softwood or coniferous
  • Softwood lignins are often characterized as being derived from coniferyl alcohol or guaiacylpropane (4- hydroxy-3-methoxyphenylpropane) monomer.
  • Hardwood lignins contain polymers of 3,5-dimethoxy-4-hydroxyphenylpropane monomers in addition to the guaiacylpropane monomers.
  • the grass lignins contain polymers of both of these monomers, plus 4-hydroxyphenylpropane monomers.
  • Hardwood lignins are much more heterogeneous in structure from species to species than the softwood lignins when isolated by similar procedures.
  • Representative sources of cellulose fibers include, but are not limited to, wood and non-wood plants having sources of cellulose such as soy, rice, cotton, cereal straw, flax, bamboo, reeds, esparto grass, jute, flax, sisal, abaca, hemp, bagasse, kenaf, Sabai grass, milkweed floss fibers, pineapple leaf fibers, switch grass, lignin-containing plants, and the like.
  • the source of cellulose fibers can be virgin or waste/recycle cellulose fibers, or a combination thereof.
  • Typical fiber lengths for a variety of pulped cellulosic fibers are set forth in Table 1 below: Table 1 : Unbeaten, Unbleached Pulp Fibers
  • Hardwood and softwood fibers can be blended into a single article to achieve a desired combination of strength, whiteness, writing surface or other required characteristics.
  • the mixed characteristics of recovered fibers makes them particularly suited to applications such as paper, newsprint and packaging. Examples of different sources of hardwoods and softwoods, and their attributes, are described in Table 2. Table 2
  • Kraft softwood fiber is a low yield fiber made by the well-known Kraft (sulfate) pulping process from coniferous material and includes Northern and Southern softwood Kraft fiber, Douglas fir Kraft fiber and so forth.
  • Kraft softwood fibers generally have a lignin content of less than 5 percent by weight, a length weighted average fiber length of greater than 2 mm, as well as an arithmetic average fiber length of greater than 0.6 mm.
  • Kraft hardwood fiber is made by the Kraft process from hardwood sources, i.e., Eucalyptus, and has generally a lignin content of less than 5 percent by weight.
  • Waste/recycle fiber may be used as the sole source of the cellulose fiber in the Composition, or it may be added to virgin cellulose fibers in the Composition and in any amount. While any suitable waste/recycle fiber may be used, waste/recycle fiber with relatively low levels of groundwood can be employed in many cases, such as office waste that contains less than 15% by weight lignin content, or less than 10% by weight lignin content. Newsprint waste can contain high quantities of lignin, such as above 10 wt.%, or 20-40 wt.% lignin.
  • cellulose fibers can be fed to a hydropulper as a pulp containing water or as dried pulped material
  • a pulp is a composition containing water and liberated plant based cellulose fibers processed by any of the many pulping processes familiar to one experienced in the art including sulfate, sulfite, polysulfide, soda pulping, BCTMP, PGW, TMP, CTMP, APMP, etc. as further described below.
  • the production of a pulp starts with a source of cellulose as mentioned above, and when a wood source is used, first the wood is debarked, chipped, and optionally depithed. The chipped wood is then subjected to mechanical, chemical, or a combination of chemical and mechanical processes to make the pulp.
  • Mechanical pulp is the refining of wood chips in the presence of atmospheric conditions, steam treatment, chemical treatment or steam/chemical treatment. Mechanical pulping obtains a mixture of fibers and fiber fragments without removing the lignin yielding a lower quality paper with a higher tendency to discolor over time. Examples of suitable
  • thermomechanical pulp processes include the bleached chemical thermomechanical pulp (BCTMP) process, the pressure groundwood pulping process (PGW), thermomechanical pulp processes (TMP),
  • CTMP chemithermomechanical pulp processes
  • APMP alkaline peroxide mechanical pulp processes
  • PGW pulp utilizes all the wood and is useful to make newsprint and where high quality over a long-life span is not required since such pulp contains impurities that can discolor weaken the paper strength.
  • TMP pulps can also be used in newsprint and are usually stronger than PGW, and therefore also find uses in tissue and paperboard.
  • the CTMP pulps use a combination of mechanical processing and chemical processes by applying sodium sulfite, carbonate or hydroxide to soften the pulp.
  • the pulp can be further processed in a pulp mill to remove additional impurities through washing, screening, and subjected to additional defibering or de-knotting.
  • a full chemical pulp process dissolves lignin and hemicellulose from the cellulose fibers using a cooking liquor, pressure and steam.
  • Paper made from chemical pulps are also known as wood-free papers because they do not contain mechanical pulp lignin, which deteriorates over time.
  • the pulp can also be bleached to produce white paper.
  • Chemical pulps can be more easily bleached than mechanical pulps because the chemical processes generally remove much of the lignin and hemi-cellulose from the cellulose source.
  • the whiteness of pulp is measured by its ability to reflect
  • the pulp can be bleached if desired by chemical means including the use of chlorine, chlorine dioxide, oxygen, peracids, sodium hypochlorite, hydrogen and alkaline peroxide, and so forth. Desirably, oxygen is employed in the bleaching process and avoid the use of any process using chlorine. Bleached pulps processed without elemental chlorine or hypochlorite are referred to as (ECF) of Elemental Chlorine Free. An even more stringent bleach sequence has been achieved when mills go to (TCF) or Totally Chlorine Free.
  • ECF Elemental Chlorine Free
  • Waste/recycle paper pulp can also be used in the Compositions to make wet laid products.
  • Paper recycling processes can use paper/board obtained from either chemically or mechanically produced pulp. By mixing the waste sources of paper/board with water and applying mechanical action the hydrogen bonds in the paper can be broken and fibers separated again.
  • Recycled papers can be made from 100% recycled materials or blended with virgin pulp, although they are (generally) not as strong nor as bright as papers made from the latter. Most paper made from waste/recycle paper contains a proportion of virgin fiber for the sake of strength and quality.
  • Pre-consumer waste This is offcut and processing waste, such as guillotine trims and envelope blank waste; it is generated outside the paper mill and could potentially go to landfill and is a genuine recycled fiber source; it includes de-inked pre consumer (recycled material that has been printed but did not reach its intended end use, such as waste from printers and unsold publications). This category is included within the meaning of waste/recycle pulp or paper/board.
  • Postconsumer waste This is fiber from paper that has been used for its intended end use and includes office waste, magazine papers and newsprint. As the vast majority of this material has been printed - either digitally or by more
  • Mill broke or internal mill waste incorporates any substandard or grade-change paper made within the paper mill itself, which then goes back into the manufacturing system to be re-pulped back into paper.
  • Such out-of- specification paper is not sold and is therefore often not classified as genuine reclaimed recycled fiber, however most paper mills have been reusing their own waste fiber for many years, long before recycling became common.
  • this category of waste is referred to as“broke” pulp and is not classified as waste/recycle paper or waste/recycle pulp as used
  • Compositions and wet laid products are not limited, and may comprise a blend of conventional fibers (whether derived from virgin pulp or waste/recycle sources) and high coarseness lignin-rich tubular fibers, such as bleached chemical thermomechanical pulp (BCTMP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP) alkaline peroxide mechanical pulp (APMP) and the groundwood pulp (GWD), in each case bleached or unbleached, deinked, and can be processed chemically by the Kraft method to make Kraft pulps (both sulfate and sulfite) and bleached Kraft pulps.
  • BCTMP bleached chemical thermomechanical pulp
  • TMP thermomechanical pulp
  • CMP chemithermomechanical pulp
  • APMP alkaline peroxide mechanical pulp
  • GWD groundwood pulp
  • Recycled pulps may or may not be bleached in the recycling stage. Any of the pulps described above which have not previously been subjected to bleaching may be bleached as described herein to provide a bleached pulp material.
  • the Composition can be a furnish, can be suitable as a feed or in any composition prior to refining, can contain virgin non-fibrillated cellulose fibers, can contain refined cellulose fibers, can contain co-refined cellulose fibers (which can include broke), and can include a combination of non- fibrillated virgin and waste/recycle cellulose fibers.
  • the source of cellulosic fiber is obtained from wood, whether hardwood, softwood, or a combination thereof.
  • the Composition contains pulped cellulose fibers, or is obtained by combining pulped cellulose fibers to the CE staple fibers.
  • pulped cellulose fibers are combined with CE staple fibers, or are present in the Composition, or are present in the wet laid products containing the Composition or obtained from the Composition in an amount of at least 60 wt.%, or greater than 70 wt.%, or at least 71 wt.%, or at least 72 wt.%, or at least 75 wt.%, or at least 80 wt.%, or at least 90 wt.%, or at least 95 wt.%, or at least 98 wt.%, or at least 99 wt.%, or 100 wt.%, based on the weight of all cellulose fibers (not including CE staple fibers) in the Composition or wet laid product. At 100 wt.%, no unpulped cellulose fibers are present.
  • wood pulp is present in the Composition or wet laid products containing or obtained from the composition in an amount of at least 60 wt.%, or greater than 70 wt.%, or at least 75 wt.%, or at least 80 wt.%, or at least 90 wt.%, or at least 95 wt.%, or at least 98 wt.%, or at least 99 wt.%, or 100 wt.%, in each case based on the weight of all cellulose fibers (not including CE staple fibers) in the Composition or wet laid product.
  • the remainder of the cellulose fibers can non-pulped and non-wood pulped, and desirably are pulped cellulose fibers obtained from non-wood plant-based sources.
  • non wood cellulose fibers are present in the Composition or wet laid products containing or obtained from the composition in an amount of at less than 95 wt.%, or not more than 80 wt.%, or not more than 60 wt.%, or not more than 50 wt.% or not more than 40 wt.% or not more than 30 wt.% or not more than 25 wt.% or not more than 20 wt.% or not more than 15 wt.% or not more than 10 wt.%, in each case based on the weight of all cellulose fibers in the
  • the remainder of the cellulose fibers can wood sourced cellulose fibers, desirably pulped wood sourced cellulose fibers.
  • the percentage of pulped non-wood cellulose fibers can be at least 30 wt.%, or at least 40 wt.%, or at least 50 wt.%, or at least 60 wt.%, or at least 70 wt.%, or at least 80 wt.%, or at least 90 wt.%, or at least 95 wt.%, based on the weight of all cellulose fibers in the Composition.
  • Composition fed to a refiner, or the effluent from a refiner, or the Composition, or wet laid products containing or obtained from the Composition contain less than 5 wt.%, or not more than 3 wt.%, or not more than 1 wt.%, or not more than 0.5 wt.%, or not more than 0.25 wt.%, or not more than 0.1 wt.%, or not more than 0.01 wt.%, or not more than 0.001 wt.%, or not more than 0.0001 wt.%, of fiber bundles, based on the weight of the Composition.
  • the Composition contains virgin non-fibrillated cellulose fibers, or co-refined virgin cellulose fibers, in an amount of at least 25 wt.%, or at least 50 wt.%, or at least 50 wt.%, or at least 60 wt.%, or at least 70 wt.%, or at least 80 wt.%, or at least 90 wt.%, or at least 95 wt.%, or at least 98 wt.% or 100 wt.%, based on the weight of all cellulose fibers in the composition.
  • the Composition contains waste/recycle cellulose fibers, or co-refined waste/recycle cellulose fibers, in an amount of at least 25 wt.%, or at least 50 wt.%, or at least 50 wt.%, or at least 60 wt.%, or at least 70 wt.%, or at least 80 wt.%, or at least 90 wt.%, or at least 95 wt.%, or at least 98 wt.%, or 100 wt.%, based on the weight of all cellulose fibers in the composition.
  • the Composition can also contain a mix of virgin cellulose fibers and waste/recycle cellulose fibers.
  • the Composition contains at least a cellulose fiber.
  • the cellulose fiber contained in the Composition are either:
  • a virgin non-fibrillated cellulose fiber is a fiber that has either not been subjected to any refining operation at all, or is a fiber that has not been subjected to beating or refining after preparation of a commercial pulp product that is ready for use or received to a wet laid process facility (e.g. ready as a feed to a stock preparation zone in a wet laid process). While the pulp may have minimal or marginal degree of fibrillation imparted to the cellulose fibers in the pulp preparation step, nevertheless, non-fibrillated cellulose fibers are those fibers that are not subjected to beating or refining after the pulp preparation step.
  • the degree of fibrillation imparted, if any, during the pulp preparation process is insufficient to produce a wet laid product that is fit for use.
  • the wet laid process as referred throughout the description does not include the processes for making pulp from wood or other plants by any of the methods described above, e.g. BCTMP, TMP, CTMP, APMP, GWD, and the Kraft method. Although some of these processes for preparing pulps can result in minor amounts of fibrillation of cellulose, the degree of fibrillation is ineffective to obtain useful wet laid products. Compositions containing virgin non-fibrillated cellulose are useful as feeds to a refining operation as discussed in greater detail below.
  • Virgin fibrillated cellulose fibers are cellulose fibers that, after having been pulped, are subjected to a refining operation to fibrillate the fibers.
  • Co-refined cellulose fibers are those in which the cellulose fibers have been fibrillated by the action of a refiner in the presence of CE staple fibers.
  • the co-refined cellulose fibers can be virgin, waste/recycle fibers, or a combination thereof.
  • the waste/recycle cellulose fibers used in the Compositions can be either fibrillated or non-fibrillated, but in most cases, the fibers have already been fibrillated when made as virgin products.
  • any reference to a Composition includes cellulose present as any one of a) and/or b) above prior to refining, and includes b), c) and/or d) above after refining, unless the context dictates otherwise.
  • CE staple fiber The cellulose ester staple fiber (“CE staple fiber”) in the
  • Composition and wet laid products containing or obtained by the Composition are a form of a CE polymer.
  • Suitable CE polymers include cellulose derivatized with a reactive compound to generate at least one ester linkage at the hydroxyl site on the cellulose backbone, such as cellulose acetate, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate formate, cellulose acetate propionate, cellulose acetate butyrate, cellulose propionate butyrate, and mixtures thereof.
  • cellulose acetate Although described herein with reference to“cellulose acetate,” it should be understood that one or more of the above cellulose acid esters or mixed esters may also be used to form the fibers. Various types of cellulose esters are described, for example, in U.S. Patent Nos. 1 ,698,049; 1 ,683,347;
  • regenerated cellulose e.g ., viscose, rayon, or lyocell
  • the fibers made therefrom are not classified as CE polymers or CE staple fibers.
  • the CE staple fibers are desirably virgin CE staple fibers.
  • Cellulose ester fibers obtained from other sources are typically contaminated with additives or printing material.
  • cellulose ester fibers obtained from cigarette filters have plasticizers such as triacetin, which, as explained below, can contribute to agglomeration of the Composition in refining or flocculation of the resulting web.
  • Printing material applied to cellulose ester fibers renders them undesirable unless first subjected to a de-inking process.
  • the CE staple fibers are desirably not refined, or non-fibrillated, upon combining them with cellulose fibers, or prior to feeding the Composition to a refiner.
  • the Composition can contain a combination of cellulose fibers and non- fibrillated CE staple fibers, meaning that the CE staple fibers have not been refined to fibrillate the CE staple fibers.
  • a process for cutting filaments to make the CE staple fibers is not considered a refining process or one which fibrillates the CE staple fibers.
  • CE staple fibers It is desirable not to refine the CE staple fibers separately from cellulose fibers, since the CE staple fibers will be combined with cellulose fibers and the combination will be subjected to refining, or the non-fibrillated CE staple fibers will be added after the cellulose fibers have been refined, in each case necessary to obtain one or more of the effects of the invention.
  • a non-fibrillated CE staple fiber is one which contains less than an average of not more than 3 fibrils/staple fiber, or not more than an average of 2 fibrils/staple fiber, or not more than an average of 1 fibril/staple fiber, or not more than an average of 1 fibril/staple fiber, or not more than an average of 0.5 fibril/staple fiber, or not more than an average of 0.25 fibril/staple fiber, or not more than an average of 0.1 fibril/staple fiber, or not more than an average of 0.05 fibril/staple fiber, or not more than an average of 0.01 fibril/staple fiber, or not more than an average of 0.001 fibril/staple fiber, or not more than an average of 0.0001 fibril/staple fiber.
  • a non-refined CE staple fiber is one which has not undergone a refining operation.
  • the Composition can include CE staple fibers which are either non-fibrillated, non-refined, or both.
  • Compositions made at any stage before refining as described below include non-fibrillated, or non- refined, or both non-fibrillated and non-refined CE staple fibers.
  • the CE staple fiber will not substantially fibrillate.
  • the cellulose ester can have a degree of substitution that is not limited, although a degree of substitution in the range of from 1.8 to 2.9 is desirable.
  • degree of substitution or“DS” refers to the average number of acyl substituents per anhydroglucose ring of the cellulose polymer, wherein the maximum degree of substitution is 3.0.
  • the cellulose ester used to form fibers as described herein may have a degree of substitution of at least 1.8, or at least 1.90, or at least 1.95, or at least 2.0, or at least 2.05, or at least 2.1 , or at least 2.15, or at least 2.2, or at least 2.25, or at least 2.3 and/or not more than about 2.9, or not more than 2.85, or not more than 2.8, or not more than 2.75, or not more than 2.7, or not more than 2.65, or not more than 2.6, or not more than 2.55, or not more than 2.5, or not more than 2.45, or not more than 2.4, or not more than 2.35.
  • At least 90, or at least 91 , or at least 92, or at least 93, or at least 94, or at least 95, or at least 96, or at least 97, or at least 98, or at least 99 percent of the cellulose ester has a degree of substitution of at least 2.15, or at least 2.2, or at least 2.25.
  • acetyl groups can make up at least about 1 , 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60 percent and/or not up to 100% or not more than about 99, or not more than 95, or not more than 90, or not more than 85, or not more than 80, or not more than 75, or not more than 70 percent of the total acyl substituents.
  • greater than 90 weight percent, or greater than 95%, or greater than 98%, or greater than 99%, and up to 100 wt.% of the total acyl substituents are acetyl substituents (C2).
  • the cellulose ester can have no acyl substituents having a carbon number of greater than 2.
  • the DS of the cellulose ester polymer is not more than 2.5, or not more than 2.45.
  • CE staple fibers Both the industrial and home compostability of CE staple fibers is most effective when made with cellulose esters having a DS of not more than 2.5.
  • CE staple fibers made with cellulose ester polymers having a DS of not more than 2.5 are also soil biodegradable under the ISO 17566 test method.
  • the cellulose ester may have a weight-average molecular weight (Mw) of not more than 90,000, measured using gel permeation
  • the cellulose ester may have a molecular weight of at least about 10,000, at least about 20,000, 25,000, 30,000, 35,000, 40,000, or 45,000 and/or not more than about 100,000, 95,000, 90,000, 85,000, 80,000, 75,000, 70,000, 65,000, 60,000, or 50,000.
  • the CE staple fibers are mono-component fibers, meaning that there are no discrete phases, such as islands, domains, or sheaths of alternate polymers in the fiber other than the CE polymer.
  • a mono-component fiber can be entirely made of CE polymer, or a melt blend of a CE polymer and a different polymer.
  • At least 60% of the composition of the CE staple fibers are CE polymers, or at least 70%, or at least 75%, or at least 80%, or at least 90%, or at least 92%, or at least 95%, or at least 98%, or at least 99%, or 100% by weight of the CE staple fibers are CE polymers, based on the weight of all polymers in the fiber having a number average molecular weight of over 500 (or alternatively based on the weight of all polymers used to spin filaments from which the CE staple fibers are made). For clarity, these percentages do not exclude spin or cutting finishes applied to the filaments once spun or other additives which have a number average molecular weight of less than 500.
  • the cellulose ester may be formed by any suitable method, and desirably the CE staple fibers are obtained from filaments formed by the solvent spun method, which is a method distinct from a precipitation method or emulsion flashing.
  • the solvent spun method the cellulose ester flake is dissolved in a solvent, such as acetone or methyl ethyl ketone, to form a “solvent dope,” which can be filtered and sent through a spinnerette to form continuous cellulose ester filaments.
  • up to about 3 wt.% or up to 2 wt%, or up to 1 weight percent, or up to 0.5 wt.%, or up to 0.25 wt.%, or up to 0.1 wt.% based on the weight of the dope, of titanium dioxide or other delusterant may be added to the dope prior to filtration, depending on the desired properties and ultimate end use of the fibers, or alternatively, no titanium dioxide is added.
  • the continuous cellulose ester filaments are then cut to the desired length leading to CE staple fibers having low cut length variability, and consistent L/D ratios, and the ability to supply them as dry fibers.
  • cellulose ester forms made by the precipitation method have low length consistency, have a random shape, a wide DPF distribution, have a wide L/D distribution, cannot be crimped, and are supplied wet.
  • the solvent dope or flake used to form the CE staple fibers may include few or no additives in addition to the cellulose ester.
  • additives can include, but are not limited to, plasticizers, antioxidants, thermal stabilizers, pro-oxidants, acid scavengers, inorganics, pigments, and colorants.
  • the CE staple fibers as described herein can include at least about 90, or at least 90.5, or at least 91 , or at least 91.5, or at least 92, or at least 92.5, or at least 93, or at least 93.5, or at least 94, or at least 94.5, or at least 95, or at least 95.5, or at least 96, or at least 96.5, or at least 97, or at least 97.5, or at least 98, or at least 98.5, or at least 99, or at least 99.5, or at least 99.9, or at least 99.99, or at least 99.995, or at least 99.999 percent cellulose ester, based on the total weight of the fiber.
  • the fibers may include or contain not more than 10, or not more than 9.5, or not more than 9, or not more than 8.5, or not more than 8, or not more than 7.5, or not more than 7, or not more than 6.5, or not more than 6, or not more than 5.5, or not more than 5, or not more than 4.5, or not more than 4, or not more than 3.5, or not more than 3, or not more than 2.5, or not more than 2, or not more than 1.5, or not more than 1 , or not more than 0.5, or not more than 0.1 , or not more than 0.01 , or not more than 0.005, or not more than 0.001 weight percent of plasticizers, or optionally all additives, in the cellulose ester polymer or deposited onto the cellulose ester fiber or contained on or in the CE staple fiber, including but not limited to the specific additives listed herein.
  • the solvent dope can be extruded through a plurality of holes to form continuous cellulose ester filaments.
  • filaments may be drawn to form bundles of several hundred, or even thousand, individual filaments. Each of these bundles, or bands, may include at least 100, or at least 150, or at least 200, or at least 250, or at least 300, or at least 350, or at least 400 and/or not more than 1000, or not more than 900, or not more than 850, or not more than 800, or not more than 750, or not more than 700 fibers.
  • the spinnerette may be operated at any speed suitable to produce filaments, which are then assembled into bundles having desired size and shape.
  • filament band such as, for example, a crimped or uncrimped tow band.
  • the filament band may be of any suitable size and, in some embodiments, may have a total denier of at least about 10,000, or at least 15,000, or at least 20,000, or at least 25,000, or at least 30,000, or at least 35,000, or at least 40,000, or at least 45,000, or at least 50,000, or at least 75,000, or at least 100,000, or at least 150,000, or at least 200,000, or at least 250,000, or at least 300,000.
  • the total denier of the tow band can be not more than about
  • any one of the cut length, shape, denier per filament, and crimp of the CE staple fiber influences one or more properties of wet laid products containing or obtained by the Compositions, such as surface smoothness, water drainage rates, absorbency, stiffness, liquid and air permeability even with the same or smaller pore sizes, nonwoven density, light-weighting, re-wettability, softness, tensile strength, in each case relative to Post-Addition CE staple instead of co-refining, or 100% cellulose
  • the individual filaments which are spun in a generally longitudinally aligned manner and which ultimately form the tow band, are of a particular size.
  • the linear denier per filament (weight in g of 9000m fiber length), or DPF, of the CE filaments and of the corresponding CE staple fibers, are desirably within a range of 0.5 to less than 3.
  • the particular method for measurement is not limited, and include ASTM 1577-07 using the FAVIMAT vibroscope procedure if filaments can be obtained from which the staple fibers are cut, or a width analysis using any convenient optical microscopy or Metso.
  • the DPF can also be correlated to the maximum width of a fiber.
  • the maximum width of a fiber is measured as the longest outermost diameter dimension, and in the case of any fiber than is not round, a convenient method for measuring the longest outer diameter is to spin the fiber.
  • Table 4 illustrates a convenient correlation of DPF to maximum widths (or outer diameter) of the fibers, regardless of shape and including multi-lobal shapes.
  • the DPF of the filaments, and of the CE staple fibers are within a range of 1.0 to 2.8, or 1.0 to 2.5, or 1.0 to 2.2, or 1.0 to 2.1 , or more desirably from 1.0 to 2.0, or 1.0 to less than 2.0, or 1.0 to 1.9, or 1.1 to 1.9, or
  • handsheets made with the Compositions in which the CE staple fibers have a DPF of less than 3 have increased air permeability relative to those made with fibers at 3 DPF or more.
  • the maximum width of the fibers are less than 31 microns, or not more than 30 microns, or not more than 28 microns, or not more than 27 microns, or not more than 26 microns, or not more than 25 microns, or not more than 24.5 microns, or not more than 24 microns.
  • the minimum widths, or diameters of the fibers are more than 1 micron (1000 nanometers), or at least 2 microns
  • microns (2000 nanometers), or at least 3 microns, or at least 4 microns, or at least 5 microns, or at least 7 microns, or at least 9 microns, or least 10 microns, or at least 12 microns, or at least 15 microns, or at least 17 microns, or at least 18 microns, or at least 20 microns.
  • At least 70%, or at least 80%, or at least 85%, or at least 90%, or at least 95%, or at least 97% of the CE staple fibers have a DPF within +/-20% of any one of the above stated DPF.
  • At least 70%, or at least 80%, or at least 85%, or at least 90%, or at least 95%, or at least 97% of the CE staple fibers have a DPF within +/- 15% of any one of the above stated DPF; or at least 70%, or at least 80%, or at least 85%, or at least 90%, or at least 95%, or at least 97% of the CE staple fibers have a DPF within +/- 10% of any one of the above stated DPF.
  • CE staple fibers 95%, or at least 97% of the CE staple fibers have a DPF within +/- 15%, or within +/- 10% of any one of the above stated DPF.
  • the DPF can have a small distribution span satisfying the following formula: where d is based on the median DPF, dg o is the value at which 90% of the fibers have a DPF less than target DPF, dio is the value at which 10% of the fibers have a DPF less than the target DPF, dso is the value at which 50% of the fibers have a DPF less than the target DPF and 50% of fibers have a DPF more than the target DPF, and S is 40%, or 35%, or 30%, or 25%, or 20%, or 15%, or 13%, or 10%, or 8%, or 7%.
  • the individual cellulose ester filaments discharged from the spinnerette, and the CE staple fibers may have any suitable transverse cross-sectional shape.
  • Exemplary cross-sectional shapes include, but are not limited to, round or other than round (non-round).
  • Non-round shapes include Y-shaped or other multi-lobal shapes such as l-shaped (dog bone), closed C- shaped, X-shaped, or crenulated shapes.
  • a cellulose ester filament, or CE staple fiber has a multi-lobal cross-sectional shape, it may have at least
  • the filaments may be symmetric along one or more, two or more, three or more, or four or more axes, and, in other embodiments, the filaments may be asymmetrical.
  • the term“cross-section” generally refers to the transverse cross- section of the filament measured in a direction perpendicular to the direction of elongation of the filament. The cross-section of the filament may be determined and measured using Quantitative Image Analysis (QIA). Staple fibers will have a cross-section similar to the filaments from which they are formed without mechanically deforming the staple fibers.
  • QIA Quantitative Image Analysis
  • the shape factor of the individual cellulose ester filaments or CE staple fibers is at least about 1 , 1.1 , 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, or 2.
  • the shape factor of the cellulose ester filaments and CE staple fibers is not more than about 5, 4.8, 4.75, 4.5, 4.25,
  • the shape factor can be calculated from the cross-sectional area of a filament, which can be measured using QIA. As used herein, a round shape would have a shape factor of less than 1.25, while a non-round shape would have a shape factor of 1.25 or more.
  • the shape of the CE staple fiber is:
  • b) has a shape factor of at least 1.25, or at least 1.3, or at least 1.5, or at least 2, or
  • c) is multi-lobal shaped, such as a Y shape, or a crenulated shape, or
  • the air permeability of wet laid products tend to decrease when made with compositions containing round shaped CE staple fibers.
  • a density of at least 0.450 g/cc wet laid product having significantly improved water permeability over a 100% Cellulose Comparative composition a round shaped fiber can used, e.g. shape factor of less than 1.25, or cut from filaments solvent spun through round holes, or targeted as round.
  • At least 70%, or at least 80%, or at least 85%, or at least 90%, or at least 95%, or at least 97%, or at least 99% of the CE staple fibers have the stated shape.
  • a filament yarn After multiple bundles are assembled into a filament yarn (or tow band), it may be passed through a crimping zone wherein a patterned wavelike shape may be imparted to at least a portion, or substantially all, of the individual filaments.
  • the filaments may not be crimped, and the uncrimped filaments may be passed directly from the spinnerette to a drying zone.
  • the crimping zone includes at least one crimping device for mechanically crimping the filament yarn.
  • Filament yarns desirably are not crimped by thermal or chemical means (e.g., hot water baths, steam, air jets, or chemical coatings), but instead are mechanically crimped using a suitable crimper.
  • a suitable type of mechanical crimper is a “stuffing box” or“stuffer box” crimper that utilizes a plurality of rollers to generate friction, which causes the fibers to buckle and form crimps.
  • Other types of crimpers may also be suitable. Examples of equipment suitable for imparting crimp to a filament yarn are described in, for example, U.S. Patent
  • the crimping step may be performed at a rate of at least about 50 m/min (75, 100, 125, 150, 175, 200, 225, 250 m/min) and/or not more than about 750 m/min (475, 450, 425, 400, 375, 350, 325, or 300 m/min).
  • the crimped CE staple fibers have an average effective length that is not more than 85 percent of the actual length of the crimped CE staple fibers.
  • the effective length refers to the maximum dimension between any two points of a fiber and the actual length refers the end-to-end length of a fiber if it were perfectly straightened. If a fiber is straight, its effective length is the same as its actual length. However, if a fiber is curved and/or crimped, its effective length will be less than its actual length, where the actual length is the end-to- end length of the fiber if it were perfectly straightened.
  • the crimped fibers have an average effective length that is not more than 80, or not more than 75, or not more than 65, or not more than 50, or not more than 40, or not more than 30, or not more than 20 percent of the actual length of the bent fibers.
  • the low DPF CE staple fibers can be susceptible to breakage when cut from the filaments, or when further processed, compared to the normal frequency of crimps imparted to higher denier fibers typically used in cigarette filter tow. Crimping is a useful component of the CE staple fiber to enhance cohesion and entanglement with the cellulosic fibers and with each other. However, given the low DPF of the fibers, a low frequency of crimps is desirable to minimize fiber breakage when the filaments are cut to staple and when they are further processed or handled prior to their combination with the cellulosic fibers, and also to retain a high degree of retained tenacity.
  • the term“retained tenacity” refers to the ratio of the tenacity of a crimped filament (or staple fiber) to the tenacity of an identical but uncrimped filament (or staple fiber), expressed as a percent.
  • a crimped fiber having a tenacity of 1.3 gram-force/denier (g/denier) would have a retained tenacity of 87 percent if an identical but uncrimped fiber had a tenacity of 1.5 g/denier.
  • the crimped cellulose ester filaments are capable of having a retained tenacity of at least about 40%, or at least 50%, or at least 60%, or at least 65%, or at least 70%, or at least 75%, or at least 80%, or at least 85%, or at least 90%, or at least 95%.
  • Crimping may be performed such that the continuous filaments from which the CE staple fibers are cut and/or the CE staple fibers themselves have a crimp frequency of at least 5, or at least 7, or at least 10, or at least 12, or at least 13, or at least 15, or at least 17, and up to 30, or up to 27, or up to 25, or up to 23, or up to 20, or up to 19 crimps per inch (CPI), measured according to ASTM D3937-12.
  • CPI crimps per inch
  • the average CPI of the filaments used to make the CE staple fibers is a value from 7 to 30 CPI, or 10 to 30 CPI, or 10 to 27 CPI, or 10 to 25 CPI, or 10 to 23 CPI, or 10 to 20 CPI, or 12 to 30 CPI, or 12 to 27 CPI, or 12 to 25 CPI, or 12 to 23 CPI, or 12 to 20 CPI, or 15 to 30 CPI, or 15 to 27 CPI, or 15 to 25 CPI, or 15 to 23 CPI, or 15 to 20 CPI.
  • the ratio of the crimp frequency CPI to DPF can be greater than about 2.75:1 , or greater than 2.80:1 , or greater than 2.85:1 , or greater than 2.90:1 , or greater than 2.95:1 , or greater than 3.00:1 , or greater than 3.05:1 , or greater than 3.10:1 , or greater than 3.15:1 , or greater than 3.20:1 , or greater than 3.25:1 , or greater than 3.30:1 , or greater than 3.35:1 , or greater than 3.40:1 , or greater than 3.45:1 , or greater than 3.50:1.
  • this ratio may be even higher, such as, for example, greater than about 4:1 , or greater than 5:1 , or greater than 6:1 , or greater than or greater than 7:1 particularly when, for example, the fibers being crimped are relatively fine.
  • the ratio of the CPI to the DPF is a useful measure to ensure that the proper CPI is imparted for a given DPF and retain the balance of necessary crimp frequency and tenacity for a given DPF.
  • desirable ratios of CPkDPF include from 4:1 to 20:1 , and especially 5:1 to 14:1 , or 7:1 to 12:1.
  • the crimp amplitude of the fibers may vary and can, for example, be at least about 0.5, or at least 0.6, or at least 0.7, or at least 0.85, or at least 0.90, or at least 0.93, or at least 0.96, or at least 0.98, or at least 1.00, or at least 1.04, in each case mm. Additionally, or in the
  • the crimp amplitude of the fibers can be up to 1.75, or up to 1.70, or up to 1.65, or up to 1.55, or up to 1.35, or up to 1.28, or up to 1.24, or up to 1.15, or up to 1.10, or up to 1.03, or up to 0.98 mm, or up to 0.85 mm, or up to 0.75 mm, or up to 0.7 mm.
  • the final staple fibers may have a crimp ratio of at least about 1 :1.
  • “crimp ratio” refers to the ratio of the non-crimped tow length to the crimped tow length.
  • the staple fibers may have a crimp ratio of at least about 1 :1 , at least about 1.1 :1 , at least about 1.125:1 , at least about 1.15:1 , or at least about 1.2:1.
  • Crimp amplitude and crimp ratio are measured according to the following calculations, with the dimensions referenced being shown in Figure 4:
  • Crimped length (Lc) is equal to the reciprocal of crimp frequency (1 /crimp frequency), and the crimp ratio is equal to the straight length (L0) divided by the crimped length (L0:Lc).
  • the amplitude (A) is calculated geometrically, as shown in Figure 4, using half of the straight length (LO/2) and half of the crimped length (Lc/2).
  • the uncrimped length is simply measured using conventional methods.
  • the CE staple fibers and/or the filaments from which the CE staple fibers are derived are crimped to improve the freeness of
  • the crimped CE staple fibers desirably can have one or more of the following features:
  • CPI or 10 to 20 CPI, or 12 to 30 CPI, or 12 to 27 CPI, or 12 to 25
  • the fibers may further be dried in a drying zone in order to reduce the moisture and/or solvent content of the filament yarn or tow band.
  • the CE staple fibers are dry, as further explained below.
  • the CE staple fibers are combined with cellulose fibers and/or water as dry CE staple fibers.
  • a dry CE staple fiber will have a moisture content of not more than 30 wt.% moisture, or not more than 25 wt.% moisture, as determined by oven dryness. The final moisture content, or level of dryness, of the filament yarn
  • CE staple fibers particularly between cutting and combining with cellulose fibers, or upon combining with or adding to cellulose fibers and/or water or into a Composition, or as fed to a hydropulper, or in bales, can be less than 1 wt.%, and desirably is at least about 1 wt.%, or at least 2 wt.%, or at least 3 wt.%, or at least 3.5 wt.%, or at least 4 wt.%, or at least 4.5 wt.%, or at least 5 wt.%, or at least 5.5 wt.%, or at least 6 wt.%, based on the total weight of the yarn or staple fibers and/or not more than about 20 wt.%, or not more than 18 wt.%, or not more than 16 wt.%, or not more than 13 wt.%, or not more than 10 wt.%, or not more than 9 wt.
  • Suitable ranges include, but are not limited to, 3-20, or 3-18, or 3- 16, or 3-13, or 3-10, or 3-9, or 3-8, or 3-7, or 3-6.5, or 4-20, or 4-18, or 4-16, or 4-13, or 4-10, or 4-9, or 4-8, or 4-7, or 4-6.5, or 5-20, or 5-18, or 5-16, or 5- 13, or 5-10, or 5-9, or 5-8, or 5-7, or 5.5-20, or 5.5-18, or 5.5-16, or 5.5-13, or
  • the CE staple fibers prior to or upon their combination with cellulose fibers or prior to their addition into a hydropulper vessel, have no liquid added to them and/or their moisture content is the equilibrium moisture of the surrounding non-moisture-controlled environment.
  • the CE staple fibers have the advantage of not requiring their maintenance as a slurry or emulsion (e.g. greater than 30 wt% water) during shipping as well as reducing shipping weight and its associated costs.
  • Any suitable type of dryer can be used such as, for example, a forced air oven, a drum dryer, or a heat setting channel. The dryer may be operated at any temperature and pressure conditions that provide the requisite level of drying without damaging the yarn.
  • the filament yarn (or tow band) may be fed to a cutting zone without first baling, or may be optionally baled and the resulting bales may be introduced into a cutting zone, wherein the yarn or tow band may be cut into staple fibers.
  • Any suitable type of cutting device may be used that is capable of cutting the filaments to a desired length without excessively damaging the fibers. Examples of cutting devices can include, but are not limited to, rotary cutters, guillotines, stretch breaking devices, reciprocating blades, and combinations thereof.
  • the cellulose ester fibers may be baled or otherwise bagged or packaged for subsequent transportation, storage, and/or use.
  • the cut length can be determined by any suitable reliable method.
  • Commonly used optical instruments include the Metso FS-5 and the Optest FQA.
  • the data output of these devices can provide information such as the average length and length distribution curve.
  • the cut length referred to herein can be the average cut length or the set point on the cutter to designate the target cut length.
  • the CE staple fiber length is generally in the range of at least 1.5 mm and up to 20 mm.
  • desirable cut lengths include a cut length of at least 2 mm, or at least 2.5 mm, and not more than about 10 mm, or not more than 8 mm, or not more than 6 mm, or not more than 5 mm, or not more than or less than 4.5 mm, or not more than or less than 4.0 mm, or not more than 3.8 mm, or not more than 3.5 mm, or not more than 3.3 mm.
  • cut length ranges include from 2 to 10 mm, or 2.5 to 8 mm, or 2.0 to 6 mm, or from 1.5 to less than 6.0, or from 2.0 to less than 6.0, or from about 3 to 6 mm, or from 2.5 to 5 mm, or from 2.5 to 4.5 mm, or from 2.5 to 4 mm, or from 2.5 to less than 4 mm, or from 2.5 to 3.8 mm, or from 2.5 to 3.5 mm.
  • the cut length of the CE staple fibers is desirably less than 6 mm, or not more than 5.5 mm, or not more than 5.0 mm, or not more than 4.5 mm, or not more than or less than 4 mm.
  • At least 70%, or at least 80%, or at least 85%, or at least 90%, or at least 95%, or at least 97% of the CE staple fibers have a cut length within +/-20% of any one of the above stated cut lengths.
  • At least 70%, or at least 80%, or at least 85%, or at least 90%, or at least 95%, or at least 97% of the CE staple fibers have a cut length within +/- 15% of any one of the above stated cut lengths; or at least 70%, or at least 80%, or at least 85%, or at least 90%, or at least 95%, or at least 97% of the CE staple fibers have a cut length within +/- 10% of any one of the above stated cut lengths.
  • at least 85%, or at least 90%, or at least 95%, or at least 97% of the CE staple fibers have a cut length within +/- 15%, or within +/- 10% of any one of the above stated cut lengths.
  • the cut length can have a small distribution span satisfying the following formula: where d is based on the median cut length, dg o is the value at which 90% of the fibers have a cut length less than target cut length, d-io is the value at which 10% of the fibers have a cut length less than the target cut length, d5o is the value at which 50% of the fibers have a cut length less than the target cut length and 50% of fibers have a cut length more than the target cut length, and S is 40%, or 35%, or 30%, or 25%, or 20%, or 15%, or 13%, or 10%, or 8%, or 7%.
  • the CE staple fibers are fibers rather than particles.
  • the CE staple fibers have an aspect ratio (L/D) of at least 1.5:1 , or at least 2:1 , or at least 2.5:1 , or at least 3:1 , or at least 3.5:1 , or at least 4:1 , or at least 5:1 , or at least 6:1 , or at least 7:1 , or at least 8:1 , or at least 9:1 , or at least 10:1 , or at least 20:1 , or at least 30:1 , or at least 40:1 , or at least 50:1.
  • L/D aspect ratio
  • the CE staple fibers are retained on a 40 mesh. Because the CE staple fibers are fibers having cut lengths of at least 1.5 mm, at least 50%, or at least 60%, or at least 80%, or at least 90%, or at least 95%, or at least 97% by weight of the CE staple fibers will not pass through, or be retained on a 40 mesh (0.420 mm openings). Since some of the CE staple fibers poured onto a 40 mesh can be vertically oriented, they can pass through but others oriented off of the vertical will be retained since their cut length is at least 1.5 mm and quickly form a mat to retain all remaining fibers.
  • the ratio of CE staple fiber cut length to DPF is less than 10:1 , or not more than 8:1 , or not more than 5:1 , or not more than 4:1 , or not more than 3.1 , optionally further with Compositions containing CE staple fibers having a cut length of less than 6 mm.
  • This ratio is a useful way to define a fiber both in terms of its cut length and DPF relationship, and we have found that both features affect one of more of the properties identified above.
  • the ratio of cut length:DPF can be not more than 2.95:1 , or not more than 2.9:1 , or not more than 2.85:1 or not more than 2.8:1 or not more than 2.75:1 or not more than 2.6:1 or not more than 2.5:1 or not more than 2.3:1 or not more than 2.0:1.
  • the cut length:DPF is not more than 3.5:1 , or not more than 3.3:1 , or not more than 3:1 , or not more than 2.95:1 , or not more than 2.8:1 , or not more than 2.5:1 at a cut length of less than 6 mm, or not more than 5 mm, or not more than 4 mm.
  • the CE staple fibers can have any one or more of the following features:
  • the CE staple fibers have a distribution span satisfying the following formula: 100 ⁇ 5
  • S is 20%, or 15%, or 13%, or 10%, or 8%, or 7%, or
  • Any suitable type of cutting device may be used that can cut the filaments to a desired length without excessively damaging the fibers.
  • cutting devices can include, but are not limited to, rotary cutters, guillotines, stretch breaking devices, reciprocating blades, and combinations thereof. Once cut, the staple fibers may be baled or otherwise bagged or packaged for subsequent transportation, storage, and/or use.
  • the fiber to fiber coefficient of dynamic friction (“F/F CODF”) and the fiber to metal coefficient of dynamic friction (“F/M CODF”) can be influenced by the application of a finish on the filaments used to make the CE staple fibers and present on the CE staple fibers.
  • a finish applied to the CE filaments also called“fiber finish” or“spin finish,” refers to any suitable type of coating that, when applied to a fiber filament modifies friction exerted by and on the fiber, and alters the ability of the fibers to move relative to one another and/or relative to a metal surface. Finishes are not the same as adhesives, bonding agents, or other similar chemical additives which, when added to fibers, prevent movement between the fibers by adhering them to one another. Finishes, when applied, continue to permit the movement of the fibers relative to one another and/or relative to other surfaces while modifying the ease of this movement by increasing or decreasing the frictional forces.
  • a spin or cutting finish is applied to the filaments and/or present on the CE staple fibers, the finish decreases the F/F CODF and/or the F/M CODF, relative to the same fiber without a finish.
  • a finish which decreases the F/F CODF and/or F/M CODF on the fibers can decrease the potential for the fibers to agglomerate or flocculate with each other during refining and/or exiting the refiner, or to decrease the potential of the fibers to agglomerate on the metal surfaces of the refiner.
  • the CE staple fibers may exhibit a fiber-to-fiber staple pad friction coefficient of friction of at least about 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, or 0.50 and/or not more than about 1 , 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, or 0.50, measured as described in U.S. Patent No.
  • the CE staple fibers may exhibit a fiber-to-metal staple pad friction coefficient of friction of at least about 0.10, 0.15, 0.20, or 0.25 and/or not more than about 0.55, 0.50, 0.45, 0.40, 0.35, or 0.30, measured as described in U.S. Patent No. 5,683,81 1.
  • the CE staple fibers may exhibit a F/F coefficient of dynamic friction (“F/F CODF”), measured on the filament yarn from which they are cut according to ASTM D3412, of at least about 0.01 , 0.02, 0.03, 0.04, 0.05, or 0.06 or 0.1 , or 0.1 1 , or 0.12, or 0.13 and/or not more than about 0.20, or 0.18, or 0.15, 0.14, 0.13, 0.12, 0.1 1 , 0.10, 0.09, 0.08, 0.07, or 0.06.
  • F/F CODF F/F coefficient of dynamic friction
  • the CE staple fibers can have an untwisted F/F CODF (also called a fiber to fiber sliding friction) between 0.1 1 to 0.20 as measured by ASTM D3412/3412M-13 on the filament yarn from which they are cut.
  • F/F CODF also called a fiber to fiber sliding friction
  • Composition, denier, shape, and CPI as the filaments used to make the CE staple fiber, or if available, the continuous filaments used to make the CE staple fiber are used, and formed into a filament yarn, and conditioned at 70 °F and 65% relative humidity for 24 hours before testing.
  • the filament yarn is measured according to ASTM D3412/3412M - 13, with the exception that only 1 twist is used, the rate is at 20 m/min, and the yarn is tested on a
  • the F/F CODF can be from 0.11 to 0.20, or from 0.11 to less than 0.20, or from 0.11 to 0.19, or from 0.1 1 to 0.18, or from 0.1 1 to 0.17, or from 0.1 1 to 0.16, or from 0.1 1 to 0.15, or from 0.12 to 0.20, or from 0.12 to less than 0.20, or from 0.12 to 0.19, or from 0.12 to 0.18, or from
  • Frictional forces are exerted through the fiber to metal contact at many stages of the wet laid production process, such as refining, pumping, screening, cleaning, blending, etc. These frictional forces can result in weakening of the fiber to the point of breakage, resulting in the development of short fiber content.
  • the F/M CODF is not more than 0.70, or not more than 0.65, or not more than 0.60, or not more than 0.59, or not more than 55, or not more than 0.52, or nor more than 0.50, or not more than 0.48, or not more than 0.47. Desirable ranges include 0.30 to 0.80, or 0.30 to 0.70, or 0.30 to 0.65, or 0.30 to 0.60, or 0.40 to 0.80, or 0.40 to 0.70, or 0.40 to
  • an anti-static finish that decreases the static electricity potential on the fibers without also decreasing the F/F CODF and/or F/M CODF. While one may apply a finish which has the dual function of decreasing the F/F CODF and reducing the static charge on the fibers, it is not necessary to separately apply a sole purpose anti-static finish once the filament yarn already has the desired F/F CODF properties since the CE staple fibers will be dispersed in water and as such, the potential for static build up is negligible if non-existent in the stock or machine zone.
  • an anti-static finish can be present on the CE staple fibers and applied to the filament yarn from which the CE staple fibers are cut if one desires to obtain anti-static properties in the wet laid articles made with the Compositions and the anti-static finish is retained on the CE staple fibers through the wet laid process for making the article.
  • the CE staple fibers can have a static electricity charge of less than 1.0 at 65 % relative humidity.
  • the test method for determining the static electricity charge of the CE staple fibers is as follows.
  • the sample is a filament yarn used to make the staple fibers.
  • the filament yarn is exposed to a controlled environment at 65% relative humidity at 70 °F for 24 hours to condition the filament yarn.
  • a two (2) foot section of the filament yarn is secured at one end, the other end is held by hand while rubbing the secured section of the filament yarn back and forth along the whole 2-foot section for 3 cycles using the side of a wooden #2 pencil.
  • the static electricity charge imparted to the filaments are measured using a Simco Electrostatic Fieldmeter Model FMX-003 or equivalent device.
  • the static electricity charge on the CE staple fibers can be no more than 1.0, or no more than 0.98, or no more than 0.96, or no more than 0.90, or no more than 0.85, or no more than 0.80, or no more than 0.78, or no more than 0.75, or no more than 0.70, or no more than 0.68, or no more than 0.58, or no more than 0.60, or no more than 0.58, or no more than 0.55, or no more than 0.50.
  • Any suitable method of applying a finish may be used and can include, for example, spraying, wick application, dipping, or use of squeeze, lick, or kiss rollers.
  • One or more types of finishes may be used.
  • the cumulative amount of all finish applied, if desired, will depend on the type of finishes, the fiber denier, cut length, and the type of CE used to impart to the CE staple fibers the desired F/F CODF and/or F/M CODF (and static electricity charge if desired).
  • the finishes may be of any suitable type and can be present on the filaments, filament yarns, tow bands, CE staple fibers, and CE staple fibers present in wet laid products and Compositions.
  • Suitable amounts of finish on the CE staple fibers can be at least about 0.01 , or at least 0.02, or at least 0.05, or at least 0.10, or at least 0.15, or at least 0.20, or at least 0.25, or at least 0.30, or at least 0.35, or at least 0.40, or at least 0.45, or at least 0.50, or at least 0.55, or at least 0.60 percent finish-on-yarn (FOY) relative to the weight of the dried CE staple fiber.
  • FOY finish-on-yarn
  • the cumulative amount of finish may be present in an amount of not more than about 2.5, or not more than 2.0, or not more than 1 .5, or not more than 1.2, or not more than 1.0, or not more than 0.9, or not more than 0.8, or not more than 0.7 percent finish-on-yarn (FOY) based on the total weight of the dried fiber.
  • the amount of finish on the fibers as expressed by weight percent may be determined by solvent extraction.
  • “FOY” or“finish on yarn” refers to the amount of finish on the yarn less any added water, and in the context of the Compositions, the percentage on yarn or tow would be deemed to correspond to the percentage on the CE staple fibers present in the
  • the desired cumulative amount of finish on the fibers is from 0.10 to 1.0, or 0.10 to 0.90, or 0.10 to 0.80, or 0.10 to 0.70, or 0.15 to 1.0, or 0.15 to 0.90, or 0.15 to 0.80, or 0.15 to 0.70, or 0.20 to 1.0, or 0.20 to 0.90, or 0.20 to 0.80, or 0.20 to 0.70, or 0.25 to 1.0, or 0.25 to 0.90, or 0.25 to 0.80, or 0.25 to 0.70, or 0.30 to 1.0, or 0.30 to 0.90, or 0.30 to 0.80, or 0.30 to 0.70, each as %FOY.
  • the CE staple fibers and the wet laid products containing the CE staple fibers can include little or no plasticizer.
  • Compositions or the wet laid products, or the combination thereof, contain not more than, or have added not more than, 5, or not more than 4.5, or not more than 4, or not more than 3.5, or not more than 3, or not more than 2.5, or not more than 2, or not more than 1.5, or not more than 1 , or not more than 0.5, or not more than 0.25, or not more than 0.10, or nor more than 0.05, or not more than 0.01 wt.% plasticizer, based on the total weight of the CE staple fibers; or the Compositions contain CE staple fibers onto which no plasticizer has been added, or the wet laid product, whether virgin CE staple fibers or waste/recycle CE staple fibers or both.
  • the plasticizer may be incorporated into the fiber itself by being blended with the solvent dope or cellulose ester flake, or the plasticizer may be applied to the surface of the fiber or filament by spraying, by centrifugal force from a rotating drum apparatus, or by an immersion bath.
  • Plasticizers are desirably not present on or in the CE staple fibers before being fed to a refiner, and plasticizers desirably are not applied to the filaments from which the CE staple fibers are cut, because plasticizers can increase the tendency of the fibers to agglomerate by the refining operation.
  • the shear forces imparted during refining can increase localized or instantaneous temperatures of the fibers, and since plasticizers depress the glass transition temperature of the polymer, the fibers will have a greater tendency to melt, fuse, or bond, and in the end agglomerate.
  • the hardness of the CE staple fibers desired to assist in fibrillating the cellulose fibers in the refiner can be compromised with the addition of plasticizer.
  • the plasticizer may be incorporated into the fiber itself by being blended with the solvent dope or cellulose ester flake, or the plasticizer may be applied to the surface of the fiber or filament by spraying, by centrifugal force from a rotating drum apparatus, or by an immersion bath.
  • Plasticizers are compounds that can decrease the glass transition temperature of a polymer.
  • plasticizers that are either not present or added to the CE staple fibers before refining (plasticizers can be added post blending to the furnish), or not present in or added to the filaments from which the CE staple fibers are derived, or if present are in low amounts, include, but are not limited to, aromatic polycarboxylic acid esters, aliphatic polycarboxylic acid esters, lower fatty acid esters of polyhydric alcohols, and phosphoric acid esters.
  • phthalate acid acetates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, dimethoxyethyl phthalate, ethyl phthalylethyl glycolate, butyl phthalylbutyl glycolate, levulinic acid esters, dibutyrates of triethylene glycol, tetraethylene glycol,
  • the amount of plasticizer added to or present on or in the CE staple fibers prior to combining with cellulose, or as a feedstock to a hydropulper, or in bales, or at any process step before refining, and/or the filaments from which the CE staple fibers are derived is either zero or not more than 2 wt.%, or not more than 1 wt.%, or not more than 0.9 wt.%, or not more than 0.8 wt.%, or not more than 0.7 wt.%, or not more than 0.6 wt.%, or not more than 0.5 wt.%, or not more than 0.4 wt.%, or not more than 0.3 wt.%, or not more than 0.2 wt.%, or not more than 0.1 wt.%, or not more than 0.09 wt.%, or not more than 0.07 wt.%, or not more than 0.05 wt.%, or not more than 0.03 wt.%
  • the CE staple fiber has a continuous matrix or phase of cellulose ester throughout its cross section, and in another embodiment, the CE staple fiber is uniformly cellulose ester, and in yet another embodiment, is also uniformly chemically homogenous.
  • the CE staple fiber contains more than 96 wt.%, or at least 97 wt.%, or at least 98 wt.%, or at least 99 wt.%, or 100 wt.% cellulose ester polymer based on the weight of the fiber.
  • the CE staple fiber desirably does not have a core/sheath structure.
  • the CE polymers used to make the CE staple fibers, and the CE staple fibers are desirably not chemically treated to alter the chemical structure of the cellulose ester upon or after the cellulose ester is spun into the filament that is used to cut to form the CE staple fiber, such as to increase the hydroxyl number of the CE staple fiber.
  • the CE staple fibers desirably are not surface hydrolyzed. Surface hydrolysis can increase the number of -OH sites on a cellulose ester to thereby increase hydrogen bonding with cellulose, which in turn increases the stiffness and/or strength of the wet laid product. Such a process, however, adds extra processing steps and is economically impractical.
  • the co-refining the Compositions can provide the necessary stiffness and/or strength without the necessity for engaging a separate and expensive step of chemically modifying the spun fiber filaments or the CE staple fibers with surface hydrolysis or other chemical treatments which alter their chemical structure.
  • the CE staple fibers are not surface hydrolyzed, for avoidance of doubt, it is meant that they are not surface hydrolyzed when they are present as a fiber, whether as an isolated fiber, as present with other fiber, when made into a furnish, or as present with other fibers in a wet laid product or sheet of paper.
  • the Compositions and the wet laid articles containing or obtained by the Compositions contain CE staple fibers in an amount of least 0.25 wt.%, or at least 0.5 wt.%, or at least 0.75 wt.%, or at least 1 wt.%, or at least 2 wt.%, or at least 3 wt.%, or at least 4 wt.%, or at least 5 wt.%, or at least 6 wt.%, or at least 7 wt.%, or at least 8 wt.%, or at least 9 wt.%, or at least 10 wt.%, or at least 12 wt.%, or at least 15 wt.%, or at least 18 wt.%, or at least 20 wt.%, based on the total weight of fibers the Composition.
  • the amount of CE staple fibers in the Composition can be up to 55 wt.%, or up to 50 wt.%, or up to 45 wt.%, or up to 40 wt.%, or up to 35 wt.%, or up to 30 wt.%, or up to 25 wt.%, or up to 20 wt.%, or up to 18 wt.%, or up to 15 wt.%, or up to 12 wt.%, or up to 10 wt.%, or up to 9 wt.%, or up to 8 wt.%, or up to 7 wt.%, or up to 6 wt.%, or up to 5 wt.%, based on the total weight of the fibers in the Composition, or alternatively, based on the weight of CE staple fibers and cellulose fibers in the Composition.
  • Composition include from 0.75 to 55, or 0.75 to 40, or 1 to 55, or 1 to 40, or 1 to 20, or 1 to 15, or 2 to 55, or 2 to 40 2 to 20, or 2 to 15, or 2 to 12, or 2 to 10, or 3 to 55, or 3 to 40, or 3 to 25, or 3 to 20, or 3 to 15, or 3 to 12, or 3 to 10, or 4 to 55, or 4 to 40, or 4 to 25, or 4 to 20, or 4 to 15, or 4 to 12, or 4 to 10, in each case based on weight percent of all fibers in the Composition, or alternatively, based on the weight of CE staple fibers and cellulose fibers in the Composition.
  • the weight ratio of cellulose fibers to CE staple fibers is not particularly limited, and useful ratios include at least 0.8:1 , or at least 1 :1 , or at least 1.5:1 , or at least 2:1 , or at least 3:1 , or at least 3.5:1 , or at least 4:1 , or at least 4.5:1 , or at least 5:1 , or at least 7:1 , or at least 8:1 , or at least 9:1 , or at least 15:1.
  • the weight ratio of cellulose to CE staple fibers can be up to 400:1 , or up to 300:1 , or up to 200:1 , or up to 150:1 , or up to 100:1 , or up to 50:1 , or up to 25:1 , or up to 20:1 , or up to 15:1 , or up to 10:1 , or up to 7:1 , or up to 5:1 , or up to 3:1 , or up to 1 :1 , or up to 0.66:1.
  • the CE staple fibers, and/or a wet laid product made with the CE staple fibers can be biodegradable, meaning that such CE staple fibers are expected to
  • the degradation can be characterized by the weight loss of a sample over a given period of exposure to certain environmental conditions.
  • the cellulose ester polymer used to form the staple fibers, the fibers, or wet laid products containing or obtained by the Composition can exhibit a weight loss of at least about 5, 10, 15, or 20 percent after burial in soil for 60 days and/or a weight loss of at least about 15, 20, 25, 30, or 35 percent after 15 days of exposure in a composter.
  • the rate of degradation may vary depending on the particular end use of the fibers, as well as the composition of the wet laid product, and the specific test. Exemplary test conditions are provided in U.S. Patent No. 5,870,988 and U.S. Patent No. 6,571 ,802, incorporated herein by reference.
  • the CE staple fibers are repulpable.
  • the term“repulpable.” as used herein, refers to any one or more of nonwoven products made with the Composition that has not been subjected to heat setting and is capable of disintegrating at 3,000 rpm at consistencies below 15% after any one or more of 5,000, 10,000, or 15,000 revolutions according to TAPPI Standards.
  • the wet laid products containing or obtained by the Composition can also exhibit enhanced levels of environmental non-persistence, characterized by better-than-expected degradation under various
  • Fibers and fibrous wet laid articles can meet or exceed passing standards set by international test methods and authorities for industrial compostability, home compostability, and/or soil biodegradability.
  • a material must meet the following four criteria: (1 ) the material must be biodegradable; (2) the material must be disintegrable; (3) the material must not contain more than a maximum amount of heavy metals; and (4) the material must not be ecotoxic.
  • biodegradable generally refers to the tendency of a material to chemically decompose under certain environmental conditions.
  • Biodegradability is an intrinsic property of the material itself, and the material can exhibit different degrees of biodegradability, depending on the specific conditions to which it is exposed.
  • the term“disintegrable” refers to the tendency of a material to physically decompose into smaller fragments when exposed to certain conditions. Disintegration depends both on the material itself, as well as the physical size and configuration of the article being tested. Ecotoxicity measures the impact of the material on plant life, and the heavy metal content of the material is determined according to the procedures laid out in the standard test method.
  • CE staple fibers, and the wet laid products containing or obtained by the Composition are industrially compostable, home compostable, or both.
  • the CE staple fibers used, or the wet laid products containing or obtained by the Composition can satisfy four criteria:
  • the disintegrated content supports future plant growth as humus; where each of these four conditions are tested per the ASTM D6400, or ISO 17088, or EN 13432 method.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby can exhibit a biodegradation of at least 70 percent in a period of not more than 50 days, when tested under aerobic composting conditions at ambient temperature (28 °C ⁇ 2°C) according to ISO 14855-1 (2012).
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby can exhibit a biodegradation of at least 70 percent in a period of not more than 49, 48, 47, 46, 45, 44, 43, 42, 41 , 40, 39,
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby can exhibit a total biodegradation of at least about 71 , or at least 72, or at least 73, or at least
  • a material must exhibit a biodegradation of at least 90 percent in total (e.g., as compared to the initial sample), or a biodegradation of at least 90 percent of the maximum degradation of a suitable reference material after a plateau has been reached for both the reference and test item.
  • the maximum test duration for biodegradation under home compositing conditions is 1 year.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and the products made thereby, may exhibit a
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may exhibit a
  • the fibers may exhibit 100 percent biodegradation within not more than 1 year, measured according 14855-1 (2012) under home composting conditions.
  • compositions containing the CE staple fibers, and/or the wet laid products made thereby may exhibit a biodegradation of at least 90 percent within not more than about 350, or not more than 325, or not more than 300, or not more than 275, or not more than 250, or not more than 225, or not more than 220, or not more than 210, or not more than 200, or not more than 190, or not more than 180, or not more than 170, or not more than 160, or not more than or not more than 150, or not more than 140, or not more than 130, or not more than 120, or not more than 1 10, or not more than 100, or not more than 90, or not more than 80, or not more than 70, or not more than 60, or not more than 50 days, measured according 14855-1 (2012) under home composting conditions.
  • compositions containing the CE staple fibers, and/or the wet laid products made thereby can be at least about 97, or at least 98, or at least 99, or at least 99.5 percent biodegradable within not more than about 70, or not more than 65, or not more than 60, or not more than 50 days of testing according to
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may be considered biodegradable according to, for example, French Standard NF T 51 -800 and Australian Standard AS 5810 when tested under home composting conditions.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby can exhibit a biodegradation of at least 60 percent in a period of not more than 45 days, when tested under aerobic composting conditions at a temperature of 58 °C ( ⁇ 2°C) according to ISO 14855-1 (2012).
  • they can exhibit a biodegradation of at least 60 percent in a period of not more than 44, or not more than 43, or not more than 42, or not more than 41 , or not more than 40, or not more than 39, or not more than 38, or not more than 37, or not more than 36, or not more than 35, or not more than 34, or not more than 33, or not more than 32, or not more than 31 , or not more than 30, or not more than 29, or not more than 28, or not more than 27 days when tested under these conditions, also called“industrial composting conditions.” These may not be aqueous or anaerobic conditions.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby can exhibit a total biodegradation of at least about 65, or at least 70, or at least 75, or at least 80, or at least 85, or at least 87, or at least 88, or at least 89, or at least 90, or at least 91 , or at least 92, or at least 93, or at least 94, or at least 95 percent, when tested under according to ISO 14855- 1 (2012) for a period of 45 days under industrial composting conditions.
  • This may represent a relative biodegradation of at least about 95, or at least 97, or at least 99, or at least 100, or at least 102, or at least 105, or at least 107, or at least 1 10, or at least 1 12, or at least 115, or at least 1 17, or at least 1 19 percent, when compared to cellulose fibers subjected to identical test conditions.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may exhibit a biodegradation of at least 90 percent within not more than 180 days, measured according 14855-1 (2012) under industrial composting conditions.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may exhibit a biodegradation of at least about 91 , or at least 92, or at least 93, or at least 94, or at least 95, or at least 96, or at least 97, or at least 98, or at least 99, or at least 99.5 percent within not more than 180 days, or the fibers may exhibit 100 percent biodegradation within not more than 180 days, measured according 14855-1 (2012) under industrial composting conditions.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may exhibit a biodegradation of least 90 percent within not more than about 175, or not more than 170, or not more than 165, or not more than 160, or not more than 155, or not more than 150, or not more than 145, or not more than 140, or not more than 135, or not more than 130, or not more than 125, or not more than 120, or not more than 1 15, or not more than 1 10, or not more than 105, or not more than 100, or not more than 95, or not more than 90, or not more than 85, or not more than 80, or not more than 75, or not more than 70, or not more than 65, or not more than 60, or not more than 55, or not more than 50, or not more than 45 days, measured according 14855-1 (2012) under industrial composting conditions.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby can be at least about 97, 98, 99, or 99.5 percent biodegradable within not more than about 65, or not more than 60, or not more than 55, or not more than 50, or not more than 45 days of testing according to ISO 14855-1 (2012) under industrial composting conditions.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may be considered biodegradable according ASTM D6400 and ISO 17088 when tested under industrial composting conditions.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may exhibit a soil biodegradation of at least 60 percent within not more than 130 days, measured according to ISO 17556 (2012) under aerobic conditions at ambient temperature.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby can exhibit a biodegradation of at least 60 percent in a period of not more than 130, or not more than 120, or not more than 1 10, or not more than 100, or not more than 90, or not more than 80, or not more than 75 days when tested under these conditions, also called“soil composting conditions.” These may not be aqueous or anaerobic conditions.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby can exhibit a total biodegradation of at least about 65, or at least 70, or at least 72, or at least 75, or at least 77, or at least 80, or at least 82, or at least 85 percent, when tested under according to ISO 17556
  • CERTCO a material must exhibit a biodegradation of at least 90 percent in total (e.g., as compared to the initial sample), or a biodegradation of at least 90 percent of the maximum degradation of a suitable reference material after a plateau has been reached for both the reference and test item.
  • the maximum test duration for biodegradability under soil compositing conditions is 2 years.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may exhibit a biodegradation of at least 90 percent within not more than 2 years, 1.75 years, 1 year, 9 months, or 6 months measured according ISO 17556 (2012) under soil composting conditions.
  • compositions containing the CE staple fibers, and/or the wet laid products made thereby may exhibit a biodegradation of at least about 91 , or at least 92, or at least 93, or at least 94, or at least 95, or at least 96, or at least 97, or at least 98, or at least 99, or at least 99.5 percent within not more than 2 years, or the fibers may exhibit 100 percent biodegradation within not more than 2 years, measured according ISO 17556 (2012) under soil composting conditions.
  • compositions containing the CE staple fibers, and/or the wet laid products made thereby may exhibit a biodegradation of at least 90 percent within not more than about 700, 650, 600, 550, 500, 450, 400, 350, 300, 275, 250, 240, 230, 220, 210, 200, or 195 days, measured according 17556 (2012) under soil composting conditions.
  • Compositions containing the CE staple fibers, and/or the wet laid products made thereby can be at least about 97, or at least 98, or at least 99, or at least 99.5 percent biodegradable within not more than about 225, or not more than 220, or not more than 215, or not more than 210, or not more than 205, or not more than 200, or not more than 195 days of testing according to ISO 17556 (2012) under soil composting conditions.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may meet the requirements to receive The OK biodegradable SOIL conformity mark of Vingotte and to meet the standards of the DIN Gepruft Biodegradable in soil certification scheme of DIN CERTCO.
  • CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may include less than 1 , or not more than 0.75, or not more than 0.50, or not more than 0.25 weight percent of components of unknown biodegradability, based on the weight of the CE staple fiber.
  • the fibers or fibrous wet laid articles described herein may include no components of unknown
  • the wet laid products including wet laid non-woven articles may also be compostable under home and/or industrial conditions.
  • a material is considered compostable if it meets or exceeds the requirements set forth in EN 13432 for biodegradability, ability to disintegrate, heavy metal content, and ecotoxicity.
  • the CE staple fibers or fibrous wet laid articles described herein may exhibit sufficient compostability under home and/or industrial composting conditions to meet the requirements to receive the OK compost and OK compost HOME conformity marks from Vingotte.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and the products made thereby may have a volatile solids concentration, heavy metals and fluorine content that fulfill all of the requirements laid out by EN 13432 (2000). Additionally, the CE staple fibers may not cause a negative effect on compost quality (including chemical parameters and ecotoxicity tests).
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby can exhibit a disintegration of at least 90 percent within not more than 26 weeks, measured according to ISO 16929 (2013) under industrial composting conditions.
  • the fibers or fibrous wet laid articles may exhibit a disintegration of at least about 91 , or at least 92, or at least 93, or at least 94, or at least 95, or at least 96, or at least 97, or at least 98, or at least 99, or at least 99.5 percent under industrial composting conditions within not more than 26 weeks, or the fibers or wet laid articles may be 100 percent disintegrated under industrial composting conditions within not more than 26 weeks.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may exhibit a disintegration of at least 90 percent under industrial compositing conditions within not more than about 26, or not more than 25, or not more than 24, or not more than 23, or not more than 22, or not more than 21 , or not more than 20, or not more than 19, or not more than 18, or not more than 17, or not more than 16, or not more than 15, or not more than 14, or not more than 13, or not more than 12, or not more than 1 1 , or not more than 10 weeks, measured according to ISO 16929 (2013).
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may be at least 97, or at least 98, or at least 99, or at least 99.5 percent disintegrated within not more than 12, or not more than 1 1 , or not more than 10, or not more than 9, or not more than 8 weeks under industrial composting conditions, measured according to ISO 16929 (2013).
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby can exhibit a disintegration of at least 90 percent within not more than 26 weeks, measured according to ISO 16929 (2013) under home composting conditions.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may exhibit a disintegration of at least about 91 , or at least 92, or at least 93, or at least 94, or at least 95, or at least 96, or at least 97, or at least 98, or at least 99, or at least 99.5 percent under home composting conditions within not more than 26 weeks, or the fibers or wet laid articles may be 100 percent disintegrated under home composting conditions within not more than 26 weeks.
  • compositions containing the CE staple fibers, and/or the wet laid products made thereby may exhibit a disintegration of at least 90 percent within not more than about 26, or not more than 25, or not more than 24, or not more than 23, or not more than 22, or not more than 21 , or not more than 20, or not more than 19, or not more than 18, or not more than 17, or not more than 16, or not more than 15 weeks under home composting conditions, measured according to ISO 16929 (2013).
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may be at least 97, or at least 98, or at least 99, or at least 99.5 percent disintegrated within not more than 20, or not more than 19, or not more than 18, or not more than 17, or not more than 16, or not more than 15, or not more than 14, or not more than 13, or not more than 12 weeks, measured under home composting conditions according to ISO 16929 (2013).
  • the Compositions containing the CE staple fibers, and/or the wet laid products made thereby can achieve higher levels of biodegradability and/or compostability without use of additives that have traditionally been used to facilitate environmental non-persistence of similar fibers.
  • additives can include, for example, photodegradation agents, biodegradation agents, decomposition accelerating agents, and various types of other additives.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby have been found to exhibit enhanced biodegradability and compostability when tested under industrial, home, and/or soil conditions, as discussed previously.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may be substantially free of photodegradation agents added after the CE staple fibers are combined with cellulose fibers, or added during or after cellulose fibers have been hydropulped in a stock preparation zone.
  • one of the CE staple fibers themselves, the Compositions, the wet laid products containing or made with the Compositions, or any combination thereof may contain not more than about 1 , or not more than 0.75, or not more than 0.50, or not more than 0.25, or not more than 0.10, or not more than 0.05, or not more than 0.025, or not more than 0.01 , or not more than 0.005, or not more than 0.0025, or not more than 0.001 weight percent of photodegradation agent, based on the total weight of the fiber, or the CE staple fibers may include no photodegradation agents.
  • photodegradation agents include, but are not limited to, pigments which act as photooxidation catalysts and are optionally augmented by the presence of one or more metal salts, oxidizable promoters, and combinations thereof.
  • Pigments can include coated or uncoated anatase or rutile titanium dioxide, which may be present alone or in combination with one or more of the augmenting components such as, for example, various types of metals.
  • photodegradation agents include benzoins, benzoin alkyl ethers, benzophenone and its derivatives, acetophenone and its derivatives, quinones, thioxanthones, phthalocyanine and other photosensitizers, ethylene-carbon monoxide copolymer, aromatic ketone-metal salt sensitizers, and combinations thereof.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may be substantially free of biodegradation agents and/or decomposition agents.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may include not more than about 1 , or not more than 0.75, or not more than 0.50, or not more than 0.25, or not more than 0.10, or not more than 0.05, or not more than 0.025, or not more than 0.01 , or not more than 0.005, or not more than 0.0025, or not more than 0.0020, or not more than 0.0015, or not more than 0.001 , or not more than 0.0005 weight percent of biodegradation agents and/or decomposition agents, based on the total weight of the fiber, or the fibers may include no biodegradation and/or decomposition agents.
  • biodegradation and decomposition agents include, but are not limited to, salts of oxygen acid of phosphorus, esters of oxygen acid of phosphorus or salts thereof, carbonic acids or salts thereof, oxygen acids of phosphorus, oxygen acids of sulfur, oxygen acids of nitrogen, partial esters or hydrogen salts of these oxygen acids, carbonic acid and its hydrogen salt, sulfonic acids, and carboxylic acids.
  • biodegradation and decomposition agents include an organic acid selected from the group consisting of oxo acids having 2 to 6 carbon atoms per molecule, saturated dicarboxylic acids having 2 to 6 carbon atoms per molecule, and lower alkyl esters of said oxo acids or said saturated dicarboxylic acids with alcohols having from 1 to 4 carbon atoms.
  • Biodegradation agents may also comprise enzymes such as, for example, a lipase, a cellulase, an esterase, and combinations thereof.
  • biodegradation and decomposition agents can include cellulose phosphate, starch phosphate, calcium secondary phosphate, calcium tertiary phosphate, calcium phosphate hydroxide, glycolic acid, lactic acid, citric acid, tartaric acid, malic acid, oxalic acid, malonic acid, succinic acid, succinic anhydride, glutaric acid, acetic acid, and combinations thereof.
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may also be substantially free of several other types of additives that have been added to other synthetic fibers to encourage environmental non-persistence.
  • additives can include, but are not limited to, polyesters, including aliphatic and low molecular weight (e.g., less than 5000) polyesters, enzymes, microorganisms, water soluble polymers, water-dispersible additives, nitrogen-containing compounds, hydroxy-functional compounds, oxygen- containing heterocyclic compounds, sulfur-containing heterocyclic
  • the CE staple fibers, and the Compositions containing the CE staple fibers, and/or the wet laid products made thereby may include not more than about 0.5, or not more than 0.4, or not more than 0.3, or not more than 0.25, or not more than 0.1 , or not more than 0.075, or not more than 0.05, or not more than 0.025, or not more than 0.01 , or not more than 0.0075, or not more than 0.005, or not more than 0.0025, or not more than 0.001 weight percent of these types of additives, based on the weight of the CE staple fibers, or based on the weight of all fibers.
  • the CE staple fibers may be free of the addition of any of these types of additives.
  • a wet laid product can be compostable in industrial environment (in accordance with EN 13432 or ASTM D6400) meeting the following four criteria:
  • Biodegradation determined by measuring the carbon dioxide produced by the sample under controlled composting conditions following ISO 14855-1 :2012, where the sample is mixed with compost and placed in a bioreactor at 58 °C under continuous flow of humidified air. At the exit, the CO2 concentration is measured and related to the theoretical amount that could be produced regarding the carbon content of the sample.
  • the wet laid products described in embodiment can also be compostable in industrial and backyard or home composting conditions.
  • Compostability of CE staple fibers with a DS of 2.5 or below can be achieved without adding any biodegradation and decomposition agents, e.g. hydrolysis assistant or any intentional degradation promoter additives.
  • the wet laid products can be biodegradable in soil medium in accordance with ISO 17556:2003 testing protocol.
  • biodegradation and decomposition agents e.g.
  • hydrolysis assistant or any intentional degradation promoter additives can be added to a wet laid product or be contained within the CE staple fibers.
  • the decomposition agent can be chosen in such a way that it does not impact the article shelf-life or does not impact the plant-growth when it is a part of the soil.
  • Those additives can promote hydrolysis by releasing acidic or basic residues, and/or accelerate photo or oxidative degradation and/or promote the growth of selective microbial colony to aid the disintegration and
  • these additives can have an additional function such as improving the processability of the article or improving mechanical properties.
  • decomposition agents include inorganic carbonate, synthetic carbonate, nepheline syenite, talc, magnesium hydroxide, aluminum hydroxide, diatomaceous earth, natural or synthetic silica, calcined clay, and the like. If used, it is desirable that these fillers are dispersed well in the polymer matrix. The fillers can be used singly, or in a combination of two or more.
  • aromatic ketones used as an oxidative decomposition agent include benzophenone, anthraquinone, anthrone, acetylbenzophenone, 4-octylbenzophenone, and the like. These aromatic ketones may be used singly, or in a combination of two or more.
  • transition metal compound used as an oxidative decomposition agent examples include salts of cobalt or magnesium, such as aliphatic carboxylic acid (C12 to C20) salts of cobalt or magnesium, or cobalt stearate, cobalt oleate, magnesium stearate, and magnesium oleate. These transition metal compounds can be used singly, or in a combination of two or more.
  • decomposition agent include rare earths belonging to periodic table Group 3A, and oxides thereof. Specific examples thereof include cerium (Ce), yttrium (Y), neodymium (Nd), rare earth oxides, hydroxides, rare earth sulfates, rare earth nitrates, rare earth acetates, rare earth chlorides, rare earth
  • carboxylates and the like. More specific examples thereof include cerium oxide, ceric sulfate, ceric ammonium Sulfate, ceric ammonium nitrate, cerium acetate, lanthanum nitrate, cerium chloride, cerium nitrate, cerium hydroxide, cerium octylate, lanthanum oxide, yttrium oxide, Scandium oxide, and the like. These rare earth compounds may be used singly, or in a combination of two or more.
  • Examples of basic additives selected can be at least one basic additive is selected from the group consisting of alkaline earth metal oxides, alkaline earth metal hydroxides, alkaline earth metal carbonates, alkali metal carbonates, alkali metal bicarbonates, ZhO and basic AI203.
  • the at least one basic additive can be MgO, Mg(OH)2, MgC03, CaO, Ca(OH)2, CaC03, NaHC03, Na2C03, K2C03, ZhO KHC03 or basic AI203.
  • MgO, ZhO, CaO and AI203 can be employed.
  • organic acid additives include acetic acid, propionic acid, butyric acid, valeric acid, citric acid, tartaric acid, oxalic acid, malic acid, benzoic acid, formate, acetate, propionate, butyrate, valerate citrate, tartarate, oxalate, malate, maleic acid, maleate, phthalic acid, phthalate, benzoate, and combinations thereof.
  • hydrophilic polymer or biodegradation promoter may include glycols, polyethers, and polyalcohols or other biodegradable polymers such as poly(glycolic acid), poly(lactic acid), polydioxanes, polyoxalates, poly(a-esters), polycarbonates, polyanhydrides, polyacetals, polycaprolactones, poly(orthoesters), polyamino acids, aliphatic polyesters such as poly(butylene)succinate, poly(ethylene)succinate, starch, regenerated cellulose, or aliphatic-aromatic polyesters such as PBAT.
  • biodegradable polymers such as poly(glycolic acid), poly(lactic acid), polydioxanes, polyoxalates, poly(a-esters), polycarbonates, polyanhydrides, polyacetals, polycaprolactones, poly(orthoesters), polyamino acids, aliphatic polyesters such as poly(butylene)succ
  • Sucrose ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol caprate caprylate, butylene glycol,
  • the solids content in the Composition is predominantly a fiber content.
  • the weight of fibers is more than 50 wt.%, or at least 60 wt.%, or least 70 wt.%, or at least 80 wt.%, or at least 85 wt.%, or at least 90 wt.%, or at least 95 wt.%, or at least 96 wt.% based on the weight of all polymers (including solids made from polymers) or based on the weight of all solids in the Composition, or wet laid products containing or made from the
  • the CE staple fibers and cellulose fibers in combination make up at least 50 wt.%, or at least 60 wt.%, or at least 70 wt.%, or at least 75 wt.%, or at least 80 wt.%, or at least 90 wt.%, or at least 95 wt.%, or at least 98 wt.%, or at least 99 wt.%, or at least 99.5 wt.%, or 100 wt.% of all the fibers present in the
  • compositions and/or wet laid articles of the invention or in the alternative, of all solids in the Composition or in the alternative based on the weight or all polymers (including solids made from polymers) in the Composition.
  • the wet laid products containing or obtained from the Composition contain at least 55 wt.% fibers, or at least 60 wt.% fibers, or at least 70 wt.% fibers, or at least 80 wt.% fibers, or at least 85 wt.% fibers, or at least 90 wt.% fibers, or at least 95 wt.% fibers, or at least 96 wt.% fibers, or at least 97 wt.% fibers, or at least 98 wt.% fibers, or at least 99 wt.% fibers, based on the weight of the wet laid web or article.
  • These fibers are any fibrous material, including but not limited to cellulose fibers and CE staple fibers and, if present, any other fibers such as those mentioned below.
  • Raw Materials Other Fibers
  • CE staple fibers In addition to the CE staple fibers, other synthetic fibers may be included in the Compositions and wet laid articles.
  • the other synthetic fibers are those fibers that are, at least in part, synthesized or derivatized through chemical reactions, or regenerated.
  • synthetic fibers suitable for use in a blend with CE staple fibers can include, but are not limited to, rayon, viscose, mercerized fibers or other types of regenerated cellulose (conversion of natural cellulose to a soluble cellulosic derivative and subsequent regeneration) such as lyocell (also known as Tencel), Cupro, Modal, acetates such as polyvinylacetate, glass, polyamides including nylon, polyesters such as those polyethylene
  • PET polycyclohexylenedimethylene terephthalate
  • PCT polycyclohexylenedimethylene terephthalate
  • olefinic polymers such as polypropylene and polyethylene
  • polycarbonates poly sulfates, poly sulfones, polyethers, polyacrylates, acrylonitrile copolymers
  • PVC polyvinylchloride
  • PVC polylactic acid, polyglycolic acid, sulfopolyester fibers, and combinations thereof.
  • the synthetic fibers other than the CE staple fibers, may be single-component fibers, while, in other cases, the other synthetic fibers can be multicomponent fibers containing islands in a sea, or sheaths, or discrete domains of two or more polymers. Desirably, the other synthetic fibers are single-component fibers.
  • One or more synthetic fibers other than the CE staple fibers may be present in an amount of at least 0.25 wt.%, or at least 0.5 wt.%, or at least 0.75 wt.%, or at least 1 wt.%, or at least 2 wt.%, or at least 3 wt.%, or at least 4 wt.%, or at least 5 wt.%, or at least 6 wt.%, or at least 7 wt.%, or at least 8 wt.%, or at least 9 wt.%, or at least 10 wt.%, and up to 30 wt.%, or up to 25 wt.%, or up to 20 wt.%, or up to 18 wt.%, or up to 15 wt.%, or up to 12 wt.%, or up to 10 wt.%, or up to 9 wt.%, or up to 8 wt.%, or up to 7
  • the weight ratio of CE staple fibers to other synthetic fibers can be 1 :0 to 1 :2, or 1 :0 to 1 :1.5, or 1 :0 to 1 :1.15, or 1 :0 to 1 :1 , or 1 :0 to 1 :0.9, or 1 :0 to 1 :0.6, or 1 :0 to 1 :0.4, or 1 :0 to 1 :0.3, or 1 :0 to 1 :0.2, or 1 :0 to 1 :0.1 , or 1 :0 to 1 :0.05, or 1 :0 to 1 :0.025, or 1 :0 to 1 :0.01 , based on the weight of CE staple fibers and any other synthetic fibers.
  • the Compositions do not contain any kinds of fibers other than cellulose fibers and CE staple fibers, especially those Compositions present at any stage before refining.
  • the amount of synthetic fibers other the CE staple fibers is desirably not more than 5 wt.%, or not more than 2 wt.%, or not more than 1 wt.%, or not more than 0.5 wt.%, or not more than 0.25 wt.%, or not more than 0.1 wt.%, or not more than 0.05 wt.%, or zero %, based on the weight of all synthetic fibers in the Composition, or in the alternative, based on the weight of all the fibers in the Composition.
  • a variety of other synthetic fibers present in the Composition during refining can cause agglomeration or lack of homogeneity in the Composition post refining. If other synthetic fibers are added to enhance one or more properties of a wet laid product, it is desirable to combine them with a Composition that has already been co-refined.
  • the wet laid process includes one or more zones for making wet laid products. While many zones are described for a representative example of a wet laid process since advantages can be seen in several zones, not all the zones are required to make a wet laid product. Further, the order of the zones as described is a representative example the order of each zone can be altered if desired depending upon the particular manufacturer’s needs, products to be made, and equipment constraints.
  • a typical wet laid process can be described as a stock preparation zone 700 from which a Composition is fed through a line 761 to a wet laid machine zone 800, from which the product is delivered to customers as a finished product, or if further processing is required, by a delivery means 871 , such as truck, rail car, fork lift, belts, etc., to an optional conversion zone 1000, the conversion zone being external to the wet laid machine zone facility or integrated with it.
  • Finished product (that requires no additional chemical or mechanical treatment) can be furnished and delivered from the wet laid machine zone 800 or from the conversion zone 1000 through a similar delivery means 1001 as from the machine zone 800.
  • the process as shown in Figure 2 is one example of a stock preparation zone 700.
  • Any known or conventional process configuration for making wet laid products is suitable, and desirably, at least a Refining Zone is present.
  • the configuration of the stock preparation zone 700 includes a Refining Zone 730 and one or more optional zones; for example, a
  • Waste/recycle pulped fiber sheets can be fed to a waste/recycle hydropulper in the waste/recycle Flydropulping Zone 770m that can in turn feed the first Flydropulper Zone 710, or the First Blending Zone 720, or a Second Blending
  • Broke zone 780 can feed the first Flydropulper Zone 710 through line 781 , or the First Blending Zone 720 through line 782, as a feed to the Refiner Zone 730 through line 783, to the Second Blending Zone 740 through line 784, or to the Machine Chest Zone 750 through line 785.
  • the wet laid machine zone 800 can include a head box zone 810, a Wire Zone 820, a Press Zone 830, a First Drying Zone 840, a Sizing Zone 850, a second drying zone 860 and a finishing zone 870.
  • the broke zone 780 collects waste pulp, and trim and paper when the machine line is not processing finished product, from one or more of the zones in the wet laid machine zone 800.
  • Pulp mills and wet laid facilities may exist separately or as integrated operations.
  • An integrated mill is one that conducts pulp manufacturing on the site of the wet laid facility, or within 2 miles or even 1 ⁇ 2 mile of each other.
  • Nonintegrated mills have no capacity for pulping but must bring pulp to the mill from an outside source.
  • Integrated mills have the advantage of using common auxiliary systems for both pulping and papermaking such as steam, electric generation, and wastewater treatment. Transportation costs are also reduced.
  • Non- integrated mills require less land, energy, and water than integrated mills.
  • the Composition containing the fibers and optional pigments, additives and chemistries are combined and diluted with water in preparation as a feed to the wet laid machine zone 800.
  • the raw materials are generally warehoused, at least a portion combined in a hydropulper and hydropulped (if delivered to the mill in dry bale form), optionally blended with some or all additives, refined, blended with pigments, additives, synthetic fibers, and waste/recycle pulp, then cleaned/screened to give the desired furnish for a particular grade of paper.
  • This Composition is then pumped to the machine chest in preparation as a feed to the wet laid machine zone 800.
  • the blended Composition can be pumped from the machine chest as a thick stock through a tickle refiner, stuff box, and lastly through a basis weight valve which controls the fiber delivery to the head box in the wet laid machine.
  • the typical start for making wet laid products is to stage the ingredients, such as in a warehouse. Due to the large quantity of pulp required to supply a modern paper machine, adequate warehouse space should be available with a detailed and accurate inventory control systems. Some larger paper machines require hydropulper loadings of truck trailer amounts of fiber in a single batch.
  • An integrated facility may retain the pulped cellulose fibers in aqueous suspension containing about 4-20 wt.% solids that is then pumped to the Hydropulping Zone 710.
  • the integrated facility, or a non-integrated facility may also store compressed bales of dried pulped cellulose having a moisture content from 3 to 18 wt.% as sources of feed to the hydropulper.
  • the cellulose fibers are dispersed.
  • a hydropulping vessel in the Hydropulping Zone 710 is fed through line 10 with a source of virgin cellulose fibers, and optionally through line 10 or other feed line 771 with waste/recycle source of cellulose fiber to make a furnish in the hydropulper.
  • Compressed bales of dried cellulose fiber, and/or the aqueous suspension of cellulose fibers, are fed to the hydropulper and dispersed in water.
  • the feed of cellulose fibers to the hydropulper is virgin non-fibrillated cellulose fibers, optionally dry cellulose fiber having a moisture content of less than 60 wt.%.
  • Compositions can contain water, and "furnishes” and“stock” and like terminology refer to Compositions including at least:
  • compositions suitable as isolated compositions, as feed streams, as effluents, present in any vessel or line or equipment at any stage, or used to make any wet laid product, or contained in any wet laid product after draining water and drying can be made by combining virgin cellulose fibers, CE staple fibers having a DPF of less than 3 that are either dry, obtained from solvent spun filaments, or both, and water, and the weight of fibers in the Composition is more than 50 wt.% based on the weight of all solids in said Composition.
  • the Composition can contain or be made by combining virgin cellulose fibers, CE staple fibers having a DPF of less than 3 and an average length of less than 6 mm, in which those CE staple fibers are added either dry, obtained from solvent spun filaments, or both, and water.
  • the Composition can contain or be made by combining virgin cellulose fibers, crimped CE staple fibers, and water.
  • the Composition can contain or be made by combining virgin cellulose fibers, non-round, crimped CE staple fibers having a denier per filament DPF of less than 3, an average length of less than 6 mm, and water.
  • a process for making a furnish composition by combining virgin cellulose fibers, CE staple fibers, and water in a hydropulping vessel, and agitating the cellulose fibers, CE staple fibers, and water to obtain a furnish composition having a consistency of less than 50 wt.%.
  • the Flydropulping Zone 710 is not particularly limited and includes sheets, emulsions, slushes, slurries, dispersions, flakes, or chopped particulate solid matter.
  • the Flydropulping Zone 710 may include a staging warehouse for storing and feeding solid pulped cellulose fibers, such as in the form of sheets, to the hydropulper.
  • the sheet form of cellulose fibers is typical for many wet laid facilities, even those that are integrated. Thick sheets of pulped cellulose fibers can be stacked in a warehouse in the form of bales or cubes, typically compressed, and of any dimension.
  • the dimensions of the bale containing sheets of cellulose fibers can be anything that a hydropulper can accept, and generally have dimensions equivalent to the dimensions of the stacked sheets of cellulose.
  • Suitable bale sizes are not limited, but generally are from at least (width x length x height in feet) 1’x1’x1’ and up to 4’ x 4’ x 4’, and more typical from 2.0’x 2.0’ x 2’ up to 3.5’ x 3.5’ x 3.5’, or about 47 inches by 30 inches (optionally up to any desired height), +/- 4” in any dimension.
  • Each sheet in the bale desirably has the same width and length as the bale, and the bale height is comprised of the height of the stacked sheets (discounting packaging).
  • the sheets can optionally be compressed and strapped or packaged.
  • the straps and packaging are typically removed before feeding the bale to the hydropulper.
  • the bales of stacked sheets of cellulose have the advantage of being flat on all sides and compact and small, making their stacking during shipment efficient, unlikely to tip, and stackable in most any means of transport including trucks, train cars, trailers, and ships.
  • a solid cellulose fiber source of feed to the hydropulper or any other vessel in the stock preparation zone can be as dry feed.
  • a dry feed of cellulose fibers meaning the dryness of a bale, sheets containing cellulose fibers, or loose cellulose fibers, has a moisture content of less than 60 wt.% based on oven dryness.
  • a dry feed of cellulose fibers is distinguished from an aqueous feed of cellulose fibers as a slurry.
  • a dry feed of cellulose fibers can have a moisture content of about 60 wt.% or less, or from 1 to 60 wt.%, or 1 to 55 wt.%, or 1 to 50 wt.%, or 1 to 45 wt.%, or 1 to 30 wt.%, or 1 to 25 wt.%, or 1 to 20 wt.%, 3-20 wt.%, or 3-18 wt.%, or 3-16 wt.%, or 3-13 wt.%, or 3-10 wt.%, or 4-20 wt.%, or 4-18 wt.%, or 4-16 wt.%, or 4-13 wt.%, or 4-10 wt.%, or 5-20 wt.%, or 5-18 wt.%, or 5-16 wt.%, or 5-13 wt.%, or 10 wt.%, or 5-13 wt.%, or 5-16 wt.%, or 5-13 wt.
  • the cellulose fibers can be measured by air dry % solids.
  • Air dry % solids is the condition of a fiber when its moisture content is at equilibrium with ambient atmosphere.
  • the ambient atmosphere is deemed to have a 10% moisture content and a 90% oven bone dry fiber weight content.
  • a 100% air dry is equivalent to an oven bone dry fiber weight of 90% and 10% moisture
  • a 90% air dry is equivalent to an oven bone dry fiber weight of 81 % and 19% moisture.
  • Air dry can be determined according to TAPPI 201 -cm-93.
  • the solid cellulose fibers can have an air dry % solids of at least 45%, or at least 53%, or at least 60%, or at least 70%, or at least 85%, or at least 88%, or at least 90%, or at least 93%, or at least 94%, or at least 95%, or at least 96%, or at least 97%, or at least 98%, or at least 99%, or 100%.
  • the cellulose fiber feed can be a pulped cellulose fiber feed.
  • the amount of moisture within and outside the expressed ranges can vary depending on the humidity of the storage facility and the transportation means.
  • the number of sheets per bale is not particularly limited.
  • the number of sheets can be at least 10, or at least 20, or at least 30, or at least 50, or at least 75, or at least 100, or at least 150, or at least 200.
  • the number of sheets can be up to 400, or up to 350, or up to 300.
  • the pulped cellulose does not need to be dried and solidified, but rather can be fed directly from the pulping facility as a slush, dispersion, or furnish containing water, to a Hydropulping Zone 710 in the wet laid facility or to the First Blending Zone 720.
  • a supply of cellulose pulp fibers can comprise about more than 50 wt% water and up to 50 wt.% solids.
  • cellulose fibers are liberated from a source of cellulose fibers either by mechanical action, or both mechanical and chemical action.
  • the source of cellulose if received at the wet laid facility as a solid, is repulped in a Hydropulper Zone 710 by feeding the solid pulped cellulose into a hydropulper in the Hydropulping Zone 710 and blending the cellulose with water under agitation, generally mechanical agitation using an impeller, blade, or agitator to provide shear forces and break up, separate, and disperse the solid cellulose fibers into a furnish.
  • the extent of re-pulping should enable the slurry to be pulped so that the individual fibers are completely separated from each other (deflaking).
  • the consistency of the Composition will vary throughout the wet laid process. In one or any of the embodiments mentioned, the consistency of the
  • Composition at any point in the wet laid process is more than 0.05 wt.%, or at least 0.1 wt.%, or at least 0.2 wt%, or at least 0.3 wt.%, or at least 0.4 wt.%. That minimum consistency can be maintained in and from a hydropulper, to or from the refiner, or throughout the stock preparation process up to or in the headbox or as deposited onto the wire, or throughout the entire wet laid process.
  • the consistency of the Composition within and/or exiting the hydropulper in the Hydropulping Zone 710 is less than 50 wt.%, or not more than 40 wt.%, or not more than 30 wt.%, or not more than 25 wt.%, or not more than 23 wt.%, or not more than 22 wt.%, or not more than 21 wt.%, or not more than 20 wt.%, or not more than 15 wt.%, or not more than 13 wt.%, or not more than 10 wt.%, or not more than 8 wt.%, or not more than 7 wt.%, or not more than 6 wt.%, or not more than 5.5 wt.%, or not more than 5.1 wt.%, or not more than 4.8 wt.%, or not more than 4.6 wt.%, and in each case more
  • the consistency within or as an effluent 711 from the hydropulper or as a feed 721 to a refiner in the Refining Zone 730 is within the range of from 0.1 to 8.0 wt.%, or 0.25 to 8.0 wt.%, or 0.5 to 8.0%, or from 1 to 7 wt.%, or from 1 to 6 wt.%, or from 1 to 5.5 wt.%, or from 1.5 to 5.1 wt.%, or from 2 to 4.8 wt.%, or from 2 to 4.6%, based on the weight of the
  • consistency within the hydropulper or stream 71 1 can be high and diluted downstream, and therefore, can be within the range of from 10 to 50 wt.%, or from 10 to 30 wt.%, or from 10 to 25 wt.%, or from 12 to 23 wt.%, or from 13 to 22 wt.%, or from 14 to 21 wt.%, or from 15 to 20 wt.%.
  • Suitable methods for measuring the furnish consistency of cellulosic materials are known to the skilled person.
  • a hydropulper is a large vessel mounted with a means for providing active shear forces, typically through a blade, to break up and disperse the cellulose.
  • Examples of hydropulper sizes range from small ones in the range of 4000 to 10,000 gallon vessels with an L/D of 0.5:1 to 10:1 , or 0.5:1 to 8:1 , or 0.5:1 to 6:1 , or 0.5:1 to 4:1 or 1 :1 to 3:1 and larger sizes of 20,000 to 80,000 gallons, or 30,000 to 60,000 gallons with an L/D from 0.5:1 to 10:1 , or 0.5:1 to 8:1 , or 0.5:1 to 6:1 , or 0.5:1 to 4:1 , or 1 :1 to 3:1.
  • hydropulper(s) is operated to a frequency which keeps the machine zone 800 operating in a continuous mode.
  • the hydropulper can be operated in batch, semi-batch, or continuous mode, and typically will operate in the batch mode.
  • the Hydropulping Zone 710 can contain one or more
  • the hydropulper can be operated with or without the application of thermal energy.
  • thermal energy is applied to the hydropulper to facilitate de-fiberization or de- flaking.
  • the thermal set point on a hydropulper can be at least 40 °C, or at least 45 °C, or at least 50 °C, and in each case less than 90 °C, or not more than 80 °C, or not more than 70 °C, or not more than 65 °C, or not more than 60 °C.
  • the hydropulper is desirably operated without applied thermal energy.
  • Hydropulping can be performed at ambient temperature within the range of from 20 °C. to 65 °C, or from 20 °C. to less than 50 °C. Further, the
  • hydropulping step can be performed at a pH value of from 5 to 13, or from 5 to 12, or from 5 to 9, or from 6 to 1 1 , or from 6 to 10, or from 7 to 9.
  • the Composition can have a consistency of at least 1 wt.% and up to 30 wt.% (or any of the ranges described above), containing:
  • a feed of fibers from waste/recycle sources can be combined with the CE staple fibers.
  • the combination can occur in a variety of methods, and one example is as a feed 771 to the hydropulper 710.
  • the feed of waster/recycle fibers, sheets, or pulp to the stock preparation zone have been pulped, typically in a separate waste/recycle facility, to a form suitable as a feed to a stock preparation zone in a wet laid facility for making consumer products.
  • waste/recycle facilities accept waste paper and paperboard products, described further below, and subject them to pulping, screening/cleaning, typically flotation and de-inking, and forming operations to make thick sheets.
  • a waste/recycle stream or feed means a source of waste/recycle fibers that have already been pulped, cleaned, and optionally de-inked, ready as a feed to a stock
  • preparation zone in a wet laid facility making sheet products for end use consumers or for converters who can subject the sheets to further coating, calendering, or non-destructive treatment.
  • the waste/recycle composition feed to any zone, including the waste/recycle zone 770, in any form including as a sheet, bale, or furnish can be contain from 0 wt.% to 60 wt.% CE staple fibers, or from 0.75 to 55, or 0.75 to 40, or 1 to 55, or 1 to 40, or 1 to 20, or 1 to 15, or 2 to 55, or 2 to 40 2 to 20, or 2 to 15, or 2 to 12, or 2 to 10, or 3 to 55, or 3 to 40, or 3 to 25, or 3 to 20, or 3 to 15, or 3 to 12, or 3 to 10, or 4 to 55, or 4 to 40, or 4 to 25, or 4 to 20, or 4 to 15, or 4 to 12, or 4 to 10 wt.% CE staple fibers, based on the weight of a sheet or bale of waste/recycle feed), or based on the weight of all fibers in an aqueous waste/recycle feed.
  • compositions containing waste/recycle fiber that are suitable as isolated compositions, as feed streams, as effluents, present in any vessel or line or equipment at any stage, or used to make any wet laid product, or contained in any wet laid product after draining water and drying.
  • the Composition can contain or be made by combining waste/recycle cellulose fibers, CE staple fibers having a DPF of less than 3, and water.
  • the DPF the rate of the composition
  • the Composition can contain or be made by combining waste/recycle cellulose fibers, CE staple fibers having a DPF of less than 3, and water.
  • Composition can contain or be made by combining waste/recycle cellulose fibers, cellulose ester CE staple fibers having a DPF of less than 3 and an average length of less than 6 mm, and water.
  • waste/recycle cellulose fibers cellulose ester CE staple fibers having a DPF of less than 3 and an average length of less than 6 mm, and water.
  • Composition can contain or be made by combining waste/recycle cellulose fibers, crimped CE staple fibers, water. In another embodiment, or in any of the embodiments mentioned throughout the description, the Composition can contain or be made by combining waste/recycle cellulose fibers, non-round, crimped, CE staple fibers having a DPF of less than 3, an average length of less than 6 mm, and water.
  • a waste/recycle cellulose fiber feed can be obtained from a variety of sources.
  • One source is pre-consumer waste, in which trims, offcut, and envelope waste generated outside of a wet laid facility that is eligible for landfill has not reached its intended consumer use, and includes de-inked pre consumer material; and post-consumer waste that includes office waste, magazines, newsprint, paper board, and other paper based products that been used for their intended use, and also includes de-inked waste.
  • the major categories of waste/recycle feeds to a wet laid facility can be
  • OCC a post-consumer waste sourced from old corrugated containers that can be accepted by wet laid facilities to make recycle content shipping boxes and packaging, such as shoe and cereal boxes
  • ONP a post-consumer waste sourced from used old newspapers that can be accepted by wet laid facilities to make recycle content newsprint, and for making paperboard, tissue and other products
  • Office Waste a post consumer waste sourced from printing and writing papers collected from offices, businesses, and homes
  • Mixed paper a post-consumer waste sourced from a variety of paper types, including mail, paperboard, magazines, catalogues, telephone books, etc., accepted by wet laid facilities to make a variety of products, including paperboard and tissue, and mixed with virgin cellulose to make any type of paper products
  • High Grade De-inked Paper a pre-consumer waste that can accepted by a wet laid facility to make to make higher grade paper products for printing, writing, and in tissue.
  • the more specific grades of cellulose fibers obtained from waste/recycle paper are those designated by the Institute of Scrap Recycling Industries. There are generally 51 grades, classified as follows: Mixed Paper Materials: Grade 1 ; Soft Mixed Paper: Grade 2 of sorted and clean paper types; Hard Mixed Paper: Grade 3 of clean and sorted papers having less than 10% groundwood; Boxboard Cuttings: Grade 4; Mill Wrappers: Grade 5; News: Grade 6 is newspaper; News, De-Ink Quality: Grade 7 (ONP) fresh and sorted newspapers that are not sunburned relatively free of magazines; Special News, De-Ink Quality: Grade 8 (ONP); Over-Issue News: Grade 9 (Ol or OIN) of unused, overrun newspaper; Magazines: Grade 10 (OMG) of coated magazines, catalogues, and other similar materials; Corrugated Containers: Grade 1 1 (OCC) containers having liners of test liner or Kraft; Double Sorted Corrugated: Grade 12 (DS OCC) containers generated from supermarkets and/or industrial or commercial facilities having liners of test liner
  • New Double-Lined Kraft Corrugated Cuttings Grade 13 (DLK) New corrugated cuttings having liners of Kraft without treated liners or medium, slabbed or hogged medium, butt rolls or insoluble adhesives; Fiber Cores: Grade 14 paper cores made from linerboard and/or chipboard, single or multiply plies; Used Brown Kraft: Grade 15 of used brown Kraft bags free of unwanted liners and original content; Mixed Kraft Cuttings: Grade 16 new brown Kraft cuttings, sheets and bag scrap that doesn’t contain stitched paper; Carrier Stock: Grade 17 printed or unprinted unbleached new drink carrier sheets and cuttings: New Colored Kraft: Grade 18 new colored Kraft cuttings, sheets and bag scrap; Grocery Bag Scrap (KGB): Grade 19; Kraft
  • Multiwall Bag Scrap Grade 20; New Brown Kraft Envelope Cuttings: Grade 21 of unprinted brown Kraft envelopes, cuttings or sheets; Mixed Groundwood Shavings: Grade 22 of magazine, catalogs and printed-matter trim;
  • GWCPO Grade 25 of groundwood papers used in data-processing machines (e.g. laser printing); Publication Blanks (CPB): Grade 26 of unprinted cuttings or sheets of white coated or filled groundwood content paper; Flyleaf Shavings: Grade 27 of printed trim from catalogs, magazines and other similar print materials; Coated Soft White Shavings (SWS): Grade 28 unprinted coated or uncoated shavings and sheets of white groundwood- free print paper material; Hard White Shavings (HWS): Grade 30 shavings or sheets of unprinted, untreated white paper that doesn’t contain groundwood; Hard White Envelope Cuttings (HWEC): Grade 31 of shavings or sheets of uncoated, untreated and unprinted white envelope paper free from
  • New Colored Envelope Cuttings Grade 33 of groundwood-free cuttings, shavings or sheets of uncoated, untreated bleachable colored envelope paper;
  • Semibleached Cuttings Grade 35 of untreated and unprinted that are ground-wood free such as untreated milk carton stock or manila tag or folders;
  • Unsorted Office Paper UOP: Grade 36 unprinted or print paper material generated in an office that can include document- destruction material;
  • Sorted Office Paper SOP
  • Manifold Colored Ledger (MCL) Grade 39 of shavings, cuttings and sheets of industrial-generated, groundwood-free printed or unprinted and colored or white;
  • Sorted White Ledger (SWL) Grade 40;
  • CPO Computer Printout
  • CBS Coated Book Stock
  • CCS Coated Groundwood Sections
  • Printed Bleached Board Cuttings Grade 45; Misprinted Bleached Board: Grade 46; Unprinted Bleached Board: Grade 47; #1 Bleached Cup
  • Gable-Top Cartons Grade 52 of liquid packaging board containers including empty, used, polyethylene (PE)-coated, printed one-side aseptic and gable- top cartons containing no less than 70% bleached chemical fiber;
  • Mixed Paper (MP) Grade 54 of all paper and paperboard of various qualities not limited to the type of fiber content;
  • Clean News Grade 58 of sorted newspapers from source separated collection programs, converters, drop-off centers and paper drives containing the normal percentages of roto gravure, colored and coated sections.
  • any one of these mentioned grades and categories are suitable feeds of waste/recycle fibers to be combined with CE staple fibers, optionally with virgin cellulose fibers.
  • the size of the cellulose fibers and degree of fibrillation present on cellulose fibers in waste/recycle feedstocks to a wet laid facility can vary by the source of waste.
  • waste/recycle facilities also pulp the waste/recycle paper with mechanical action that can damage the fibers by breaking or shearing them that will further reducing the fiber size or over fibrillation contributing to a decrease in the freeness of the pulp, and that in turn leads to a slower drainage rate, or reduced machine speed, or increasing susceptible to breakage in the machine zone, reduced absorbency as a product, and poor ink resolution.
  • the freeness of the pulp can be improved as is further discussed below. Further, the operator can gauge the source of the waste/recycle feedstock and determine that it is either suitable to add to a hydropulper as a 100% waste/recycle feed to a refiner where it is subjected to yet another fibrillation operation, or suitable to add to a hydropulper where it is combined with virgin cellulose and together they are refined, or added to a stream downstream of the refiner, such as in a second blending zone 740 so as not to subject the waste/recycle fibers to further fibrillation.
  • the amount of waste/recycle cellulose fibers can be at least 1 wt.%, or at least 5 wt.%, or at least 10 wt.%, or at least 15 wt.%, or at least 20 wt.%, or at least 25 wt.%, or at least 30 wt.%, or at least 35 wt.%, or at least 40 wt.%, or at least 45 wt.%, or at least 50 wt.%, or at least 55 wt.%, or at least 60 wt.%, or at least 65 wt.%, or at least 70 wt.%, or at least 75 wt.%, or at least 80 wt.%, or at least 85 wt.%, or at least 90 wt.%, or at least 95 wt.%, and even 100%, based on the weight of all cellulose fibers present in the Composition or based on the weight of
  • waste/recycle fibers can be fed directly to a hydropulper in Hydropulping Zone 710 through a feeding means 10 and there combined with CE staple fibers.
  • the waste/recycle fibers can be fed through feeding means 10 (or a different feed means) directly into the hydropulper in the Hydropulping Zone 710, or separately to a feed means 20 to a second hydropulper in a Waste/Recycle Hydropulping Zone 770 and there
  • the pulped waste/recycle fibers can be fed either to the first Hydropulping Zone 710 through line 771 , to a vessel in First Blending Zone 720 through line 772, or to a vessel in the Second
  • waste/recycle pulp from the waste/recycle hydropulper zone 770 is fed to the Second Blending Zone 740, it is combined with a cellulose fibers and CE staple fibers that have been co-refined, thereby avoiding any refinement (further fibrillation) of the waste/recycle stream from the second hydropulper in the waste/recycle Hydropulping Zone 770.
  • the Composition can contain:
  • compositions can be contained in a hydrapulper, in a blend vessel prior to refining, or as a feed stream 721 to a refiner in a Refining Zone 730, or in any stream as an effluent from a hydropulper or feed to a blend tank.
  • One or more of the waste/recycle cellulose fibers, CE staple fibers, and virgin non-fibrillated cellulose fibers can be combined or added to a vessel in sheet form in any order.
  • the Composition can be made obtained by combining together in any order:
  • the Composition made in the hydropulping exits the hydropulper in stream 711 as a pulped furnish and can fed to a Refining Zone 730 or first to an optional First Blending Zone 720.
  • the First Blending Zone 720 can be a stirred blending tank or an in-line mixer for adding one or more additives into the stream of the pulped furnish fed to the refiner.
  • the First Blending Zone 720 can be a stirred blending tank or an in-line mixer for adding one or more additives into the stream of the pulped furnish fed to the refiner.
  • 720 can also be a useful blend zone for combining waste/recycle fibers through line 772 with the virgin cellulose, leaving one the flexibility of pulping each of those fibers in zones 710 and 770 at different consistencies and developing the final desired consistency to the refiner in a first blend tank in zone 720.
  • a feed of CE staple fibers can be fed to the First Blend
  • Zone 720 through line 1 1 instead of, or in addition to, the Hydropulping Zone 710.
  • an optional feed of additional cellulose fibers can be fed to the First Blending Zone 720 through line 1 1.
  • the additives are typically combined with the pulped furnish in the blending tank or in-line mixer in amounts ranging from greater than 0% (if additives are added) up to 40 wt.%, based on the weight of all the solids in the furnish, and usually present in amounts of 0.5 wt.% to 20 wt.%.
  • compositions containing one or more additives there are a variety of different kinds of Compositions containing one or more additives, where such Compositions are suitable as isolated compositions, as feed streams, as effluents, present in any vessel or line or equipment at any stage, or used to make any wet laid product, or contained in any wet laid product after draining water and drying.
  • the compositions are suitable as isolated compositions, as feed streams, as effluents, present in any vessel or line or equipment at any stage, or used to make any wet laid product, or contained in any wet laid product after draining water and drying.
  • Composition can contain or be made by combining non-fibrillated virgin cellulose fibers or waste/recycle cellulose fibers or both; water; and one or more additives such as fillers, internal sizing agents, biocides, process anti- foaming agents, colorants, optical modifiers, or a combination thereof, where the CE staple fibers have a DPF of less than 3, or cut length of less than 6 mm, crimping, non-round with a DPF of less than 3, or a combination of any two or more of these fiber characteristics.
  • additives such as fillers, internal sizing agents, biocides, process anti- foaming agents, colorants, optical modifiers, or a combination thereof, where the CE staple fibers have a DPF of less than 3, or cut length of less than 6 mm, crimping, non-round with a DPF of less than 3, or a combination of any two or more of these fiber characteristics.
  • Examples of additives combined with the pulped cellulose, and optionally the CE staple fibers if added in the hydropulper or into the First Blending Zone 720, include fillers (e.g., talc or clay), internal sizing agents (e.g., rosin, wax, further starch, glue) and biocides. Fillers are added to improve printing properties, smoothness, brightness, and opacity. Internal sizing agents typically improve the processability of the wet laid products, and water resistance and printability of the final paper, paperboard and/or cardboard. Other additives that can be added include process anti-foaming agents, and colorants or optical modifiers such as precipitated calcium carbonate, clay, chalk or titanium dioxide to modify the optical properties of the wet laid product.
  • fillers e.g., talc or clay
  • internal sizing agents e.g., rosin, wax, further starch, glue
  • biocides e.g., rosin, wax, further starch, glue
  • Fillers are added
  • the consistency of the Composition (or furnish) within or as an effluent stream from the First Blending Zone 720 is within any of the ranges identified above with respect to the Flydropulping Zone 710.
  • the effluent from the First Blending Zone 720 is a low consistency furnish having a consistency of not more than 10 wt.%, or not more than 8 wt.%, or not more than 7 wt.%, or not more than 6 wt.%, or not more than 5.5 wt.%, or not more than 5.1 wt.%, or not more than 4.8 wt.%, or not more than 4.6 wt.%, and in each case more than 0.05 wt.%, desirably at least 0.5 wt.%, or at least 1 wt.%, or at least 1.5 wt.%, or at least 2 wt.%. Desirable consistency ranges include 0.5 to 8.0 wt.%, or from 1 to 7 wt.
  • At least a portion of the CE staple fibers are combined with the cellulose fibers and co-refined. In a co-refining operation, the cellulose fibers are fibrillated.
  • the location and method for the combination of the CE staple fibers and the cellulosic fibers is not limited, and at least a portion of each can be combined conveniently at any point prior to refining cellulosic fibers.
  • a convenient location to combine the cellulosic fibers and the CE staple fibers is in a hydropulper in the Hydropulping Zone 710 using the same feed means in or on line 10, or a second feed means (not shown).
  • the CE staple fibers may, in addition or in the alternative, be fed to a tank or in-line mixer to the optional First Blending Zone 720 through or on line 1 1 , or to stream 71 1 or 721 feeding the Refining Zone 730, or can be added downstream of the
  • the CE staple fibers can be shipped dry as sheets of cellulose ester fibers assembled into bales. Also, bales or rolls containing randomly oriented CE staple fiber can be shipped to a wet laid facility that makes wet laid products, such as market pulp manufacturers that can turn such bales into sheets containing cellulose and CE staple fibers.
  • the same feeding means e.g. conveyer system
  • the same feeding means can be employed to feed the sheets of CE staple fibers to a hydropulper
  • bales of loose CE staple fibers can be fed to any vessel in the stock preparation zone.
  • One means for feeding includes suctioning the CE staple fibers from a bale to the desired vessel.
  • Another method includes depositing the CE staple fibers dry into a stirred vessel that meters the CE staple fibers into a desired vessel for making a pulp.
  • the form of the CE staple fibers fed to the hydropulper, first blend tank, or to any vessel in the stock preparation zone is not particularly limited and includes market pulp in the form of sheets, bales of sheets, and slabs; compressed bales of loose CE staple fibers; emulsions; slushes; slurries; dispersions; flakes; or chopped particulate solid matter. Thick sheets of pulped CE staple fibers can be stacked in a warehouse in the form of bales or cubes, typically compressed, and of any dimension. [0234] In an embodiment or in any of the mentioned embodiments, there is provided a bale of sheets containing the CE staple fibers (the“CE sheets” or “CE bales”).
  • the CE sheet will contain at least 1 wt.% CE staple fibers, or at least 5 wt.%, or at least 10 wt.%, or at least 25 wt.%, or at least 35 wt.%, or at least 50 wt.%, or at least 60 wt.%, or at least 75 wt.%, or at least 90 wt.%, or at least 95 wt.%, and up to 100 wt.% CE staple fibers based on the weight of all fibers in the sheet.
  • the dimensions of the bale containing CE sheets of cellulose fibers can be anything that a hydropulper can accept, and the CE bale will generally have dimensions equivalent to the dimensions of the stacked sheets containing the CE staple fibers.
  • Suitable bale sizes are not limited, but generally are from at least (width x length x height in feet) 12”’x12”’x 12”’ and up to 120” x 120” x 120”, and more typical within a range of from 20”x 20” x 12” up to 60” x 60” x 60”, or from 20”x 20” x 12” up to 42” x 42” x 30”, or from
  • the sheets can be in a width x length range of from 20”x 20” up to 60” x 60”, or from 20”x 20” up to 42” x 42”, or from 20”x 20” up to 36” x 36”, and in each case to any desired height, but typically not exceeding 120” or not exceeding 80”, or not exceeding 60”, or not exceeding 42”.
  • Each sheet in the bale desirably has the same width and length as the bale, and the bale height is comprised of the height of the stacked sheets (discounting
  • the number of CE sheets per bale is not particularly limited.
  • the number of stacked CE sheets can be at least 10, or at least 20, or at least 30, or at least 50, or at least 75, or at least 100, or at least 150, or at least 200, and up to 400, or up to 350, or up to 300.
  • the thickness of the sheets in the bale is desirably sufficient to be self-supporting when grasped on any end. Suitable sheet thickness can be at least 1 mm, or at least 1.5 mm, or at least 2 mm, or at least 3 mm.
  • the sheet thickness can be up to 26 mm, or up to 20 mm, or up to 15 mm, or up to 12 mm, or up to 10 mm, or up to 8 mm, or up to 6 mm.
  • the bales of stacked CE sheets can have the advantage of being flat on all sides and compact and small, making their stacking during shipment efficient, unlikely to tip, and stackable in most any means of transport including trucks, train cars, trailers, and ships. In an embodiment or in any of the mentioned embodiments, at least one side of the bale is flat.
  • At least two opposing sides are flat where each of those side are the ones with the largest surface area, and in addition, optionally another two opposing sides are flat and in addition, optionally all sides of the bale are flat.
  • a platen flat plate having a weight of 500 pounds and having at least the length and width dimensions as the side, is placed at rest on the surface of that side within the dimensions of the side, no gap larger than 2 inches between the platen and the entire length of at least three of the four edges on the side in contact with the platen will be present. The measurement is taken on an unstrapped and unpackaged, un-wrapped bale.
  • the gap is desirably not larger than 1.5 inches, or not larger than 1 inch, or not larger than 0.75 inches, or not larger than 0.5 inches, or not larger than 0.25 inches, or not larger than 0.125 inches, or not larger than 0.08 inches. Desirably, the gaps are not larger than any of these values on all four edges.
  • the test can also be satisfied with any platen having a weight of less than the weight of the bale.
  • Gaps that do not run the entire length of an edge are not considered to be gaps. Gaps which vary in size along the edge are considered to have a gap size that corresponds to the smallest gap size along the edge.
  • a bale typically contains 2 to 10 slabs, or 2 to 8 slabs, or 2 to 6 slabs.
  • a slab can have a thickness of at least 2 inches, or at least 3 inches, or at least 4 inches, or at least 5 inches, or at least 6 inches, or at least 10 inches, or at least 12 inches, or at least 18 inches, or at least 24 inches.
  • Slabs are typically flash dried and slab pressed using conventional equipment. [0239] Once the sheets are stacked, they can optionally be compressed, strapped, and/or wrapped or otherwise packaged.
  • the material composition of the bale straps and/or the bale packaging are obtained from a cellulose pulp.
  • the bale packaging can be obtained from the same grade cellulose fiber pulp as the cellulose fibers to which the CE staple containing sheets will be combined.
  • the bale can be deposited into a hydropulper without removing the wrapping, particularly if the cellulose pulp from which the wrapping is made are in the same family or grade of cellulose fiber as the cellulose fiber used in the hydropulper, e.g. wrapping or packaging derived from NBSK fiber and NBSK cellulose fiber being hydropulped.
  • a bale of the CE staple fibers optionally compressed.
  • the entire bale is CE staple fibers and no cellulose fibers are added to the bale or blended with the CE staple fibers.
  • CE staple fibers can be compressed under a load, the compressed staple fibers are wrapped while under load optionally in an airtight wrapper and sealed, the wrapped bale is optionally strapped, and the load is released. Vacuum can optionally be applied to the wrapped bale to withdraw air prior to or after sealing. In this embodiment, the bale does not contain sheets or slabs.
  • the CE staple fibers can be introduced into a bale chute containing at least a portion of the wrapping, the random deposited CE staple fibers are pressed under the load of platen driven by a ram, and while under the load, wrapped or packaged at least in part.
  • Two wrapper sheets can be used for each bale, one for the bottom pulled up along the sides of the bale, and another for the top that is pulled down to overlap over the bottom wrap.
  • the strapping can be threaded around the bale and through the planten applying the load to restrain the bale while under load.
  • a CE staple fiber feed to the hydropulper or any other vessel in the stock preparation zone can be a dry feed, whether as a bale, sheets, or loose fibers.
  • a dry feed of CE staple fibers has a moisture content of less than 30 wt.%.
  • a dry feed of CE staple fibers can have a moisture content of about or 1 to 30 wt.%, or 1 to 25 wt.%, or 1 to 20 wt.%, 3-20 wt.%, or 3-18 wt.%, or 3-16 wt.%, or 3-13 wt.%, or 3-10 wt.%, or 4-20 wt.%, or 4-18 wt.%, or 4-16 wt.%, or 4-13 wt.%, or 4-10 wt.%, or 5-20 wt.%, or 5-18 wt.%, or 5-16 wt.%, or 5-13 wt.%, or 5-10 wt.%, or 6-20 wt.%, or 6-18 wt.%, or 6-16 wt.%, or 6-13 wt.%, or 6-10 wt.%, the remainder being solids.
  • the moisture content can be determined by taking the difference in weight between the pulp sample at ambient conditions and the
  • the CE staple fibers can have an air dry % solids of at least 78%.
  • the CE staple fibers can have an air dry % solids of at least 78%, or at least 80%, or at least 85%, or at least 88%, or at least 90%, or at least 93%, or at least 94%, or at least 95%, or at least 96%, or at least 97%, or at least 98%, or at least 99%, or 100%.
  • the amount of moisture within and outside the expressed ranges can vary depending on the humidity of the storage facility and the transportation means.
  • the Composition of CE staple fibers and cellulose fibers are fed to a refiner in the Refining Zone 730 so that at least a portion of the CE staple fibers and at least a portion of the cellulose fibers can be co-refined.
  • the purpose of the refiner is to fibrillate and swell the cellulose fibers resulting in improved bonding during web formation.
  • the shear forces help to break up the cell walls of the cellulose fiber to develop the fibrils.
  • Refining subjects the cellulose and CE staple fibers to tensile, shear, compressive, impact and bending forces. As a result, the cellulose fibers can experience one or more of the following phenomena:
  • the fibers can break thereby reducing their length distribution.
  • Compositions in which the cellulose fibers and CE staple fibers are co-refined, where such Compositions are suitable as isolated compositions, as feed streams, as effluents, present in any vessel or line or equipment at any stage, or used to make any wet laid product, or contained in any wet laid product after draining water and drying.
  • the Composition can contain or be made by co-refining virgin cellulose fibers and CE staple fibers that have either:
  • compositions have water and desirably the cellulose fibers and CE staple fibers are co-refined in the presence of water.
  • the Composition can contain water, fibrillated virgin cellulose fibers, and co-refined CE staple fibers that have either:
  • the Composition can contain water, cellulose fibers, an CE staple fibers, and the cellulose fibers and CE staple fibers are co-refined sufficient to impart to the composition either: 1. a Canadian Standard Freeness of any value further described below;
  • the virgin fibers can be replaced with waste/recycle fibers such that the waste/recycle fibers are co-refined with the CE staple fibers, or virgin fibers can be combined with waste/recycle fibers and together co-refined with the CE staple fibers.
  • the CE staple fibers are desirably not fibrillated after co-refining with cellulose fibers.
  • the CE staple fibers upon co-refining with cellulose fibers, do not fibrillate to any significant extent, and certainly not to the degree that cellulose fibers do.
  • a Post-Addition composition would demonstrate the same properties as a co-refined
  • a Composition yet, in spite of the lack of fibrillation on the CE staple fibers, one or more of the properties of wet laid products are modified relative to Post Addition compositions, such as the dry tensile strength or tear strength of the wet laid products.
  • a Composition that has been co-refined can contain a combination of cellulose fibers and non-fibrillated CE staple fibers that have each been refined in the presence of each other.
  • a co-refined CE staple fiber can contain an average of not more than 2 fibrils/staple fiber, or not more than an average of 1 fibril/staple fiber, or not more than an average of 1 fibril/staple fiber, or not more than an average of 0.5 fibril/staple fiber, or not more than an average of 0.25 fibril/staple fiber, or not more than an average of 0.1 fibril/staple fiber, or not more than an average of 0.05 fibril/staple fiber, or not more than an average of 0.01 fibrils/staple fiber.
  • the Composition is fed to the Refining Zone 730 to subject the cellulose fibers and the CE staple fibers to shear forces sufficient to fibrillate and swell the cellulose fibers.
  • the Composition is co-refined by subjecting the cellulose fibers and the CE staple fiber to shear forces for a time sufficient to form a Composition that has: a) a Canadian Freeness of at most 700, or at most 600, or at most 550, or at most 500, or at most 475, or at most 450, or at most 425, or at most 400, or at most 375, or at most 350, or at most 325, or at most 300, or at least 275, or at most 250; or b) a Williams Slowness of at least 5 seconds, or at least 8 seconds, or at least 10 seconds, or at least 15 seconds, or at least 20 seconds, or at least 25 seconds, or at least 40 seconds, or at least 60 seconds, or at least 70 seconds, or at least 80 seconds, or
  • Examples of maximum CSF and minimum Williams slowness can be 450/20, or 400/40, or 400/70, or 400/100, or 375/40, or 375/80, or 350/100, and so forth.
  • the maximum CSF and minimum Williams slowness can be or 700/5, or 600/8, or 550/15, or 550/25, or 550/40, or 500/20, or 475/20, and so forth.
  • the Compositions can have a higher level of freeness at a given refining energy, in another embodiment, regardless of the degree of refining, the minimum Canadian Standard Freeness can be at least 300, or at least 350, or at least 400, or at least 500, or at least 550, or at least 550, and the maximum Williams slowness in seconds can be 160s, or 140s, or 100s, or 80s, or 60s, or 40s, or 20s, or 15s, or 10s.
  • minimum CSF and maximum Williams slowness examples include 350/160, or 400/140, or 400/100, or 400/80, or 400/60, or 400/40, or 400/20, or 400/15, or 450/140, or 400/100, or 450/80, or 450/60, or 450/40, or 450/20, or 450/15, 500/140, or 500/100, or 500/80, or 500/60, or 500/40, or 500/20, or 550/60, or 500/20, or 550/15, or 550/10.
  • the extent of intimate contact and entanglement between cellulose fibers and CE staple fibers in the co-refined Composition is greater than that achieved in a Post -Additions Composition.
  • the extent of refining can, in one embodiment, be reflected in the curl value as determined in a Metso FS5 Fiber Analyzer on wet laid products containing or made from the Composition.
  • the curl value can be improved relative to Post-Addition Composition, and relative to a 100%
  • Cellulose Comparative composition by an amount of at least 3%, or at least 5%, or at least 8%, or at least 10%. This improvement can be seen with short fiber lengths of under 6 mm.
  • the curl value of wet laid products containing or obtained by the Composition can be at least 13, or at least 14, or at least 15, or at least 16, or at least 17, as determined by a Metso FS5 Fiber Analyzer.
  • a high level of refining can be targeted to a CSF of less than 350, and moderate level of refining can be targeted to a CSF of 350 to 450, and a light level of refining can target the CSF to greater than 450 and up to 650 or 700.
  • the % solids in the Composition fed to and as an effluent from the Refining Zone is desirably a low consistency Composition.
  • Suitable consistency of the Composition fed to the refiner and the effluent from the refiner are not more than 10 wt.%, or not more than 8 wt.%, or not more than 7 wt.%, or not more than 6 wt.%, or not more than 5.5 wt.%, or not more than 5.1 wt.%, or not more than 4.8 wt.%, or not more than 4.6 wt.%, and in each case more than 0.05 wt.%, desirably at least 0.25 wt.%, or at least 0.5 wt.%, or at least 1 wt.%, or at least 1.5 wt.%, or at least 2 wt.%.
  • Desirable consistency ranges include 0.25 to 8.0 wt.%, 0.25 to 7 wt.%, or from 0.25 to 6 wt.%, or from 0.25 to 5.5 wt.%, or from 0.25 to 5.1 wt.%, or from 0.25 to 4.8 wt.%, or from 0.25 to 4.6 wt.%, 0.5 to 7 wt.%, or from 0.5 to 6 wt.%, or from 0.5 to 5.5 wt.%, or from 0.5 to 5.1 wt.%, or from 0.5 to 4.8 wt.%, or from 0.5 to 4.6 wt.%, or from 1 to 7 wt.%, or from 1 to 6 wt.%, or from 1 to 5.5 wt.%, or from 1.5 to 5.1 wt.%, or from 2 to 4.8 wt.%, or from 2 to 4.6 wt.%, based on the weight of the Composition.
  • Pulp beaters are used for batch operations and for lab testing.
  • Typical pulp beaters are the Valley, Flollander, and Jones-Bertram beaters.
  • refining typically occurs through the mechanical action of bars on a rotating drum opposing a stationary bedplate on a circulating fiber suspension where the cellulose individual fibers are oriented perpendicular to the bars.
  • refining typically refers to the mechanical action carried out in continuous conical or disk-type refiner where the fibers move parallel to the bar crossings.
  • examples of these refiners and their blade elements are shown and described in US Patent Nos. 5,425,508; 5,893,525; 7,779,525; 3,1 18,622; 3,323,732; 3,326,480; 2,779,251 ; 3,305,183 and 2,934,278, which are incorporated herein by reference to the extent not inconsistent with the disclosures herein.
  • Non-limiting examples of continuous refiners that can be used to produce the co-refined Compositions include single and double and multi disk refiners, conical refiners, or conical and disk(s) refiners in combination.
  • Non limiting examples of double disk refiners include Beloit DD 3000, Beloit DD 4000, Andritz DO refiners, and Leizhan refiners.
  • Non-limiting example of a conical refiner are Sunds JC series of refiners, Escher-Wyss refiners, an Emerson Claflin refiner, or a Jordan refiner.
  • the actual response to co-refining will depend upon the type of fibers, chemistries, equipment and operating conditions being used.
  • the tear strength of long-fibered pulps generally decreases with refining due to weakening and shortening of the individual fibers.
  • the strength/toughness parameters e.g., burst, tensile, folding endurance
  • the paper furnish itself becomes slower (i.e., more difficult to drain) and the resultant paper sheets become denser (less bulky), with reduced porosity, lower opacity, and lower stiffness.
  • the design of the refining plates and operating conditions can affect characteristics of co-refinement.
  • the bar width, groove width, and groove depth of the plates characterize the refiner plates. Suitable examples of fine grooved plates bar widths are 1.3
  • Fine grooved plates have the advantage of increasing the number of fibrils on cellulose while maintaining fiber length and minimizing the production of fines.
  • parameters adjusted to achieve a well co-refined stock include the hydraulic flow of the furnish, the specific energy applied to refining, the delta of freeness drop over specific energy usage, the refining intensity, and the design of the plate.
  • the hydraulic flow is optimized to obtain optimized fibrillation and fiber strength, minimizing variations, obtaining a good fiber mat between the plates, and maintaining equipment life.
  • suitable flow rates through the cumulative number of refiners employed is at least equivalent to the operational flow rate demand of the wet laid machine.
  • the furnish consistency can impact the ability of the stock to get onto the bar edge to refine the fibers. If the consistency is too low, mat formation may be insufficient, the degree of fibrillation may lower than desired, fibers can be cut, and plate life can suffer. Consistency that is too high can plug the refiner, agglomerate the fibers, and lead to poor fibrillation
  • the consistency of the Composition fed to the refiner is between 2 wt.% to 7 wt.%, and generally within a range of 3 to about 5 wt.%.
  • the energy transferred from the refiner motor to the fibers is known as the specific energy applied, and is the motor load (e.g. kilowatts) divided by the production rate (e.g. tons/hr).
  • the specific energy required to result in good fiber development is specific to the fiber type.
  • One advantage of using the Compositions described herein is the ability to employ the same specific applied energy using a co-refined Composition to obtain higher drainage rates relative to a furnish having the same consistency without CE staple fibers.
  • the specific energy applied will vary depending on the wood type, consistency, flow, type of equipment and groove design, and refiner surface clearances. For one pass, suitable specific energy applied for co-refining the
  • CE staple fibers with the cellulose fibers at low consistencies (2-7 wt.%) can be at least 30 kWh/metric ton, or at least 50 kWh/metric ton, and generally not more than 300 kWh/t, or not more than 250 kWh/t, or not more than 200 kWh/t, or not more than 175 kWh/t.
  • gross refining energies for multipass or multi-stage operations can be at least 300 kWh/t, or can even be greater than 400 kWh/ton for certain types of wood fibers and applications.
  • the gross specific energy can range from 400 to 600 kWh/t, while Southern softwood fibers can require gross specific energy inputs of 750 kWh/Mt or more.
  • the operator has flexibility to adjust many variables to obtain a process or product advantage, such as the specific energy, intensity, consistency, plate gap, rotational speed, and flow rate.
  • a process or product advantage such as the specific energy, intensity, consistency, plate gap, rotational speed, and flow rate.
  • the drainage rate of the pulp and/or machine speed in zone 800 can be increased while keeping the specific energy applied in refining the same; or increase specific energy to reduce losses in, or maintain, or increase the dry tensile strength of wet laid products containing or made from the
  • Composition relative to a 100% Cellulose Comparative composition while maintaining or increasing Canadian freeness or decreasing Williams slowness; or reduce the specific energy applied to the Composition while improving the CSF or Williams freeness.
  • the Composition provides a faster drainage rate on the wire.
  • the speed of the machine at the wire processing the Composition is increased by at least 0.25%, or at least 0.5%, or at least 0.75%, or at least 1 %, relative to the machine speed prior to processing the Composition without change to the applied specific refiner energy.
  • the specific refining energy applied to the Composition is increased by at least 5%, or at least 10%, relative to the specific refining energy applied to a 100% Cellulose Comparative composition, to obtain a wet laid product having a dry tensile strength that is within 20%, or within 10% of the dry tensile strength of wet laid products containing or made from the Composition made with the 100%
  • the operator may want to enhance the fiber development to increase strength to a desired target at an equivalent machine speed.
  • Composition is smaller relative to a 100% Cellulose Comparative composition at a at a given specific applied energy.
  • This reduction in the CSF delta with a co-refined composition can be taken advantage of when higher refining energies are applied to develop the fiber and increase one or more strength properties without slowing the machine speed relative to the 100% Cellulose Comparative composition.
  • the CSF freeness drop is the measure of the freeness of the furnish fed to the refiner less the freeness of the effluent from the refiner. The measure of freeness is the Canadian Standard Freeness test as described below.
  • the delta of CSF freeness drop/specific energy applied using a furnish with CE staple fibers can be lowered relative to the same furnish and consistency without CE staple fibers by 2% or more, or 5% or more, or 10% or more, or 20% or more, or 30% or more, or 35% or more, or 40% or more, or 45% or more, or 50% or more, and is not particularly limited at the upper end, resulting in improved drainage rates holding the specific energy applied the same.
  • the percentage of lowering can be measured by the ((delta without CE staple - delta with CE staple)/delta without CE staple fiber) x 100 while holding the specific energy input the same.
  • the control composition without the CE staple fibers can be a 100% Cellulose
  • the number of passes through a refiner can vary depending on the desired refined pulp properties (degree of fibrillation) and equipment design.
  • the number of passes through one refiner can be one, or at least two, or from 2 to 25, and usually 6 to 12. If desired, multiple refiners can be used in series to provide the equivalent of a multi-pass operation. With a multi-pass mode, at least a portion of the refined fibers removed from the refining surfaces are recirculated back to the refining surfaces of the refiner for further refining.
  • Suitable amount of refined fibers re-circulated back to the refiner are at least 50 wt.%, or at least 60 wt.%, or at least 70 wt.%, or at least 80 wt.%, or at least 90 wt.% based on the weight of the furnish stream removed from the refiner. From the re-circulation loop, a portion of the refined fibers can be removed as the effluent of the refiner and fed downstream for further processing, with a corresponding amount of unrefined furnish feeding the refiner. [0276] A recirculation loop on a single refiner can be avoided in a multi pass mode by employing multiple refiners in series, or one may employ multiple refiners in series with at least one of the refiners operating
  • the refiner can be operated at a refining intensity between about
  • Energy intensity is a measure of how much specific energy in watts is applied across one meter of the plates bar edge and transferred to the pulp in one second, and can also be referred to as the specific edge load (SEL). It is a measure of the specific energy per impact, or the force applied to the fibers during their residence time in the refiner. If desired, the refining intensity per pass can be reduced as the number of passes through a refiner increases. Different types of cellulose respond more efficiently to different intensity ranges.
  • softwoods respond better to higher intensity (or less bar edges at a given power level).
  • the refiner can operate at a specific edge load of between about 0.75 to 4.5 Ws/m for most types of cellulose and waste/recycle cellulose.
  • the percentage of increase is measured by the SEL without (CE staple fiber - SEL with CE staple fiber)/SEL without CE staple fiber x 100.
  • time the fibers experience passing through the plates can be at least 0.25 seconds, or at least 0.5 seconds, or at least 1 second, or at least 2 seconds, or at least 4 seconds, and up to 1 minute, or up to 30 seconds, or up to 20 seconds or up to 15 seconds or up to 10 seconds, in each case per pass, optionally at no more than 10 passes.
  • Suitable residence time ranges include
  • the cumulative residence time that the Composition is co-refined is at least 2 seconds, or at least 4 seconds, or at least 6 seconds, or at least 10 seconds, or at least 15 seconds. Additionally or in the alternative, the cumulative residence time that the Composition is co-refined can be up to 30 minutes, or up to 20 minutes, or up to 15 minutes, or up to 10 minutes, or up to 5 minutes, or up to 2 minutes, or up to 1 minute, or up to 45 seconds, or up to 30 seconds, or up to 15 seconds, or up to 10 seconds.
  • Composition in a continuous multi-pass refining configuration is the residence time of the Composition between the plates multiplied by the average number of passes the feedstock would experience.
  • the average number of passes can be calculated as:
  • R recirculation ratio
  • Fr mass flow in recirculation loop in mass/time (e.g. tons/hr)
  • F mass flow to downstream operations in mass/time (e.g. tons/hr)
  • the cumulative residence time is the residence time of the Composition between the plates in each refiner added together.
  • the Composition does not need to be heated prior to entry into the refiner. Additionally, heat does not need to be applied to the Composition during refining beyond the heat generated from the mechanical action of the refiner applied to the Composition. If desired, however, thermal energy can be applied to the Composition before entering the refiner, such as through a heat exchanger. Suitable temperatures of the effluent from the refiner can be within the range of up to 150 °F, or up to 125 °F, or up to 100 °F, or up to 80 °F.
  • Composition is refined under conditions effective to obtain a Composition that has a Williams Slowness of under 180 seconds, or under 160 seconds, or under 150 seconds, or under 140 seconds.
  • the composition When adding a synthetic fiber to cellulose fibers, the composition will generally lose tensile strength relative to a 100% Cellulose Comparative composition.
  • the CE staple fibers described herein can reduce the loss of tensile strength that would be experienced with the use of other synthetic fibers. Additionally, by co-refining, the loss of tensile strength is reduced relative to the Post-Addition Composition.
  • the Composition is refined under conditions effective to reduce the loss of tensile strength relative to the Post-Addition Composition when each are compared to the tensile strength of the 100% Cellulose Comparative composition. This comparison can be made according to the following equation:
  • Cp is the loss of tensile strength of a Post-Addition Composition relative to 100% Cellulose Comparative composition
  • the percent reduction in the loss of tensile strength R is desirably at least 5%, or at least 10%, or at least 15%, or at least 20%, or at least 25%, or at least 30%.
  • the Composition is refined under conditions effective to improve the drainage rate of the
  • the Composition while minimizing the loss of tensile strength relative to the 100% Cellulose Comparative composition. This feature is expressed as a ratio of drainage rate gain to loss of tensile strength.
  • the drainage rate gain is determined by the Williams Slowness improvement as a percentage between the Composition and the 100 cellulose Comparative composition:
  • the loss of tensile in tensile strength is determined by the tensile strength of the Composition relative to the tensile strength of the 100% cellulose Composition, and in addition or in the alternative, relative to the Post-Addition composition.
  • Suitable ranges of ratios of the tensile strength of the Composition to the tensile strength of 100% cellulose Composition (and/or Post-Addition Composition) include 0.60:1 up to 1.2:1 , or 0.63:1 to 1.2:1 , or 0.66:1 to 1.2:1 , or 0.70:1 to 1.2:1 , or 0.73:1 to 1.2:1 , or 0.77:1 to 1.2:1 , or 0.83:1 to 1.2:1 , or 0.85:1 to 1.2:1 , or 0.87:1 to 1.2:1 , or 0.90:1 to 1.2:1 , or 0.95:1 to 1.2:1 , or 0.66:1 to 1.1 , or 0.70:1 to Suitable
  • the co-refined Composition (commonly known as papermaking stock) can be transferred from the Refining Zone 730 to a Second Blending Zone 740 through stream 731.
  • the Second Blending Zone nonmenclature does not imply that the wet laid process contains two blending zones, but rather, is designates as such to distinguish in the event a First Blending Zone 720 is employed.
  • the Second Blending Zone 740 can be the only blending zone in the process.
  • additives such as brightening agents, dyes, pigments, fillers, retention aids, antimicrobial agents, defoamers, pH control agents, pitch control agents, internal sizing agents, dry or wet strength polymers, adhesives and drainage aids may be added to the Composition, and are typically done so at this stage since some of these additives should not be processed through a refiner. If desired, one or more of these additives can be added to the suction into a machine chest in the Machine Zone or into the suction of the fan pump 680 prior to entry into the headbox 81 1.
  • compositions containing one or more additives there are a variety of different kinds of co-refined Compositions containing one or more additives, where such Compositions are suitable as isolated compositions, as feed streams, as effluents, present in any vessel or line or equipment at any stage, or used to make any wet laid product, or contained in any wet laid product after draining water and drying.
  • the Composition can contain or be made by combining virgin cellulose fibers and CE staple fibers that have been co-refined; water; and one or more additives comprising brightening agents, dyes, pigments, fillers, retention aids, antimicrobial agents, defoamers, pH control agents, pitch control agents, internal sizing agents, dry or wet strength polymers, adhesives, or drainage aids, or a combination thereof, and the CE staple fibers have;
  • the Composition can contain or be made by combining water, waste/recycle cellulose fibers and CE staple fibers, and optionally virgin cellulose fibers, that have all together been co-refined; water; and one or more additives comprising brightening agents, dyes, pigments, fillers, retention aids, antimicrobial agents, defoamers, pH control agents, pitch control agents, internal sizing agents, dry or wet strength polymers, adhesives, or drainage aids, or a combination thereof, and the CE staple fibers have:
  • less than 50 wt.%, or not more than 45 wt.%, or not more than 40 wt.%, or not more than 35 wt.%, or not more than 30 wt.%, or not more than 25 wt.%, or not more than 20 wt.%, or not more than 15 wt.%, or not more than 10 wt.%, or not more than 5 wt.%, or not more than 4 wt.%, or not more than 3 wt.%, or not more than 2 wt.%, or not more than 1 wt.% of solids are additives, or non-fiber polymers.
  • Blending can be accomplished in mechanically agitated or stirred CSTR vessels, fed with a slurry or dry feed.
  • Common organic pigments include styrene-based plastic pigments, acrylic-based plastic pigments, styrene-acrylic-based plastic pigments, polyethylene, microcapsules, urea resin or melamine resin, and dyes.
  • Dyes include organic compounds having conjugated double bond systems; azo compounds; metallic azo compounds; anthraquinones; triaryl compounds, such as triarylmethane; quinoline and related compounds; acidic dyes (anionic organic dyes containing sulfonate groups, used with organic rations such as alum); basic dyes (cationic organic dyes containing amine functional groups); and direct dyes (acid-type dyes having high molecular weights and a specific, direct affinity for cellulose); as well as combinations of the above-listed suitable dye compounds.
  • the pigments that are most commonly used in the papermaking industry are clay, calcium carbonate and titanium dioxide.
  • Fillers include but are not limited to calcium carbonate (calcite); precipitated calcium carbonate (PCC); calcium sulfate (including the various hydrated forms); calcium aluminate; zinc oxides; magnesium silicates, such as talc; titanium dioxide (Ti02), such as anatase or rutile; clay, or kaolin, consisting of hydrated Si02 and AI203; synthetic clay; mica; vermiculite; inorganic aggregates; perlite; sand; gravel; sandstone; glass beads; aerogels; xerogels; seagel; fly ash; alumina; microspheres; hollow glass spheres; porous ceramic spheres; cork; seeds; lightweight polymers; xonotlite (a crystalline calcium silicate gel); pumice; exfoliated rock; waste concrete products; partially hydrated or un-hydrated hydraulic cement particles; and diatomaceous earth, as well as combinations of such compounds.
  • calcite calcium carbonate
  • PCC precipitated calcium carbonate
  • Ca02 precipitated calcium
  • a dry and/or wet strength polymer can also be added to the
  • Dry and/or wet strength polymer are those polymers capable of forming hydrogen bonds to the cellulose fibers, or polymers capable of forming ionic bonds to the cellulose fibers, or polymers capable of covalently bonding to the cellulose fibers.
  • Internal sizing agents can also be added to the Second Blending Zone 740. Sizing agents can be added to aid in the development of a resistance to penetration of inks and liquids through the paper, as well as aids in maintaining web strength when processed through a sizing press in the wet laid machine zone. To avoid losses of sizing agents through the Second Blending Zone 740. Sizing agents can be added to aid in the development of a resistance to penetration of inks and liquids through the paper, as well as aids in maintaining web strength when processed through a sizing press in the wet laid machine zone. To avoid losses of sizing agents through the Second Blending Zone 740. Sizing agents can be added to aid in the development of a resistance to penetration of inks and liquids through the paper, as well as aids in maintaining web strength when processed through a sizing press in the wet laid machine zone. To avoid losses of sizing agents through the Second Blending Zone 740. Sizing agents can be added to aid in the development of a resistance to penetration of inks and liquid
  • the sizing agents are desirably added after exiting the screening/cleaning zone, or to the Machine Chest zone 600, or prior to entering the headbox.
  • Sizing agents in the stock preparation section are desirably internal sizing agents, and can be used for hard-sizing, slack-sizing, or both kinds of sizing.
  • Sizing agents can be rosin; rosin precipitated with alumina; abietic acid and abietic acid homologues such as neoabietic acid and levopimaric acid; stearic acid and stearic acid derivatives; ammonium zirconium
  • silicone and silicone-containing compounds such as RE-29 available from GE-OS1 and SM-8715, available from Dow Corning
  • R is anionic, cationic or another functional group, such as Gortex; alkylketene dimer (AKD), such as Aquapel 364, Aquapel (I 752, Fleron) 70, Flercon 79, Precise 787, Precise 2000, and Precise 3000, all of which are commercially available from Flercules, Incorporated (Willmington, Del.); and alkyl succinic anhydride (ASA); emulsions of ASA or AKD with cationic starch; ASA incorporating alum; starch; hydroxymethyl starch;
  • CMC carboxymethylcellulose
  • polyvinyl alcohol polyvinyl alcohol
  • methyl cellulose alginates
  • waxes wax emulsions
  • combinations of such sizing agents
  • Sizing agents can include retention aids.
  • retention aids are cationic polymers such as polyvinylamine polymers, or anionic microparticulate materials such as silica-based particles and clays such as bentonite, including anionic inorganic particles, anionic organic particles, water-soluble anionic vinyl addition polymers, aluminum compounds and combinations thereof.
  • Starch has many uses in papermaking. For example, it functions as a retention agent, dry-strength agent and surface sizing agent.
  • Starches include but are not limited to amylose; amylopectin; starches containing a combination of amylose and amylopectin, such as 25% amylose and 75% amylopectin (corn starch) and 20% amylose and 80% amylopectin (potato starch); enzymatically treated starches; hydrolyzed starches; heated starches, also known in the art as "pasted starches”; cationic starches, such as those resulting from the reaction of a starch with a tertiary amine to form a
  • quaternary ammonium salt anionic starches; ampholytic starches (containing both cationic and anionic functionalities); cellulose and cellulose derived compounds; and combinations of these compounds.
  • a broke composition containing broke pulp contains the co-refined cellulose fibers and CE staple fibers.
  • a broke pulp is is obtained by pulping broke.
  • Broke is a wet laid product, such as web, paper or paperboard that has not been inked and are trimmings and discarded wet laid product due to breaks during its manufacture or otherwise any discarded wet laid product during its manufacture.
  • Wet broke is wet laid product taken from the forming and pressing sections, while dry broke is wet laid product emanating from the dryers, calenders, reel, winder, and/or finishing
  • a broke Composition Prior to entering the Machine Chest Zone 750, a broke Composition can be added to the Second Blending Zone 740 through line 783 from the Broke Zone 780. Optionally, a broke Composition can be added to the Machine Chest Zone 750.
  • broke Compositions suitable as isolated compositions, as feed streams, as effluents, present in any vessel or line or equipment at any stage, or used to make any wet laid product, or contained in any wet laid product after draining water and drying.
  • the broke Composition can contain broke pulp obtained by pulping broke, and broke pulp contains water and fibrillated cellulose fibers and CE staple fibers having:
  • a stock composition by adding a broke composition to a vessel, pump, or line in the stock preparation zone 700 of a wet laid facility (e.g. to any of the zones in the stock preparation section), in which the broke composition contains broke pulp obtained by pulping broke, and the broke pulp contains the ingredients mentioned above.
  • a broke handling and re-pulping system is a typical feature in paper making processes. During threading and machine breaks, both wet and dry systems are capable of handling maximum tonnage from the machine. At the same time both systems handle small amounts on a continuous basis (e.g., couch trim at the wet end; winder trim, and slab off returns at the dry end.) Another feature of the broke system is sufficient broke capacity to sustain long periods of upset operation. From a broke pulped storage tank in the Broke Zone 780, a controlled flow is reintroduced into the stock preparation zone 700. One possible location for the introduction of a broke Composition is through line 783 into the Second Blending Zone 740.
  • broke Composition can also be fed to the hydropulper in the Hydropulping Zone 710 through line 781 and/or to the First Blending Zone 720 through line 782 and/or to the Machine Chest Zone 750 through line 784.
  • At least a portion of the CE staple fibers in the Composition are obtained from broke compositions.
  • at least 0.5 wt.%, or at least 1 wt.%, or at least 3 wt.%, or at least 5 wt.%, or at least 8 wt.%, or at least 10 wt.% of the CE staple fibers are obtained as CE staple fibers in broke compositions.
  • Repulping broke is relatively easy at the wet end as the non-dried broke readily disintegrates with low shear agitators. High shear showers and high-volume pumps keep the couch pit under control during sheet breaks and transfers contents to storage. The broke system at the dry end is much more demanding as it is repulping a dried sheet. Higher shear agitators and de- flaking equipment are usually required. Recirculation causes the slurried broke to make multiple passes through the shearing equipment.
  • the broke Composition is comprised of at least fibrillated cellulose fibers, and desirably fibrillated cellulose fibers and the CE staple fibers, and can be co-refined cellulose fibers and CE staple fibers. Any of the
  • aforementioned amounts and ratios of the cellulose fibers and CE staple fibers in the Composition can be applicable to a broke Composition.
  • the weight ratio of CE staple fibers to all fibers in the broke Composition are desirably within 30%, or within 20%, or within 10%, or within 5%, or within 3%, or within 1 % of the weight ratio of the CE staple fibers to all fibers in the
  • the solids concentration in the broke Composition is typically higher than the solids concentration in the Composition in the cleaning/screening zone.
  • the broke consistency generally ranges from 2 to 6 wt.%.
  • a process for changing over from the manufacture of one type or grade of wet laid product to another (a “change over process”) that can be conducted more efficiently as described further below.
  • the changeover process can include:
  • the CE staple fibers have:
  • the broke system ties into not only a blending zone after the refiner, but also to a hydropulper that feeds a refiner or into another pre-refiner blend zone.
  • Many types of synthetic fibers cannot be processed through the refiners without causing agglomeration in the refining machines and/or flocculation in the furnish or web.
  • the wet machine section and dry machine section each generate broke containing the synthetic fibers.
  • the broke system in those cases must be shut down, cleaned out or dumped, and flushed to prevent any synthetic fibers from finding their way into the refining section.
  • a shut down/clean out of the broke may also require a shutdown of the machine section.
  • One advantage of using the CE staple fibers is that the broke system remains operational (e.g. is not be shut down, cleaned out, flushed, and/or dumped to remove synthetic fibers) between a change over from one type of wet laid product to another type of wet laid product, such as one that does not contain a synthetic fiber. Since the CE staple fibers can be fed to a refiner and refined, re-circulation of CE staple fibers throughout the wet laid process is acceptable.
  • the stock preparation process can continue as follows. Any number and type of additional process steps can be provided between each of these steps:
  • Composition s consistency. Since a variety of pulp batches and pulp sources are used at the front-end feed to the hydropulper, and/or broke added to a Second Blending Zone 740, there can exist variability in consistency, cellulose fiber size, and cellulose fiber type even in a continuous or semi-continuous process. Additives that may be shear sensitive can be added into the machine chest such as the wet/dry strength polymers and starches.
  • the Composition is allowed to level for a retention period sufficient to reduce consistency variability and de aerate.
  • An on-line basis weight monitor within the Machine Chest Zone 750 can regulate a basis weight valve 610 to regulate the flow rate of the higher consistency Composition effluent (also called thick stock) to the Headbox and thereby provide an on target lower consistency to the Headbox.
  • the process CE staple fibers can be effectively processed within a Composition as a feed to a headbox 810.
  • a thick stock composition in a machine chest is fed to a cleaning/screening zone through a device that regulates the flow rate of thick stock, and the consistency of the thick stock fed to the screening/cleaning zone is reduced to form a thin stock composition prior to entering the any one of the screen or cleaning equipment, followed by subjecting the thin stock composition to a process for cleaning the thin stock and feeding the cleaned thin stock through screens to form a cleaned and screened thin stock composition, and then feeding the cleaned and screened thin stock composition to a headbox.
  • the Composition flowing through this process can be any of the Compositions described above, and desirably those that are co-refined.
  • the consistency of the Composition effluent from the machine chest is can be from 1 -4 wt.%, and typically from 2.0 to 3.5 wt.%, or from 2.2 to 3.1 wt.%, or 2.2-2.8 wt.%, based on the weight of the Composition.
  • the consistency of the Composition in the machine chest is higher than the consistency of the Composition fed to the headbox, and is referred to as the thick stock.
  • the thick stock Composition can be pumped, optionally through a tickle refiner, to a stuff box to provide a constant head, and lastly through a basis weight valve 610 as shown in Figure 7, which controls the consistency of the Composition to the headbox in the wet laid machine zone 800 by regulating the flow of the thick stock Composition from the machine chest.
  • the thick stock from the machine chest whose flow is regulated through a basis weight valve 610 is diluted to a 0.02 to 2.0 wt.%, desirably greater than 0.05 wt.%, or 0.1 to 2.0 wt.%, or 0.2 to 2 wt.%, or 0.5 to 1.5 wt.% consistency at the fan pump 630 by combining with white water 640 from the forming section 650 at the entrance 660 to the fan pump 630, to thereby form a thin stock having a lower consistency that the consistency of the Composition in the machine chest.
  • the white water 640 is obtained from the drainage of water from the Composition on the wire belt 821 and press rolls, which are in the forming section of the wet laid machine zone 800.
  • the white water 640 can be drawn into the fan pump 640 through a venture effect from the flow of Composition through pipe 620 into the fan pump 640.
  • the Composition, now being diluted, is pumped by the fan pump
  • a fan pump 630 is commonly used the mix the dilution Whitewater with the higher consistency Composition effluent from the machine chest to make a thin stock, an optionally targeted to the final desired consistency feed to the headbox.
  • the actual consistency of the thin stock to the headbox can vary slightly upon removal of any contaminants from the cleaning and screening processes. Desirably, the consistency of the Composition upon dilution to form a thin stock and prior to entering the cleaning operation is within 20%, or within 15%, or within 10%, or within 8%, or within 5%, or within 3% of the consistency of the thin stock Composition fed to the headbox.
  • the fan pump will control the flow rate and pressure to the headbox 81 1.
  • a constant head feed box or stuff box is normally employed having a pipe from the stuff box to and through the basis weight valve 610 before the point of dilution to control the flow and consistency.
  • the Composition Prior to entering the headbox 81 1 , the Composition is first cleaned and screened in a cleaning/screening zone 760.
  • the Composition may be subjected to a step for removing undesirable fibrous and non-fibrous material, typically through the use of one or more screens and centrifugal cleaners in a Cleaning/Screening Zone 760 downstream of the basis weight valve and fan pump.
  • concentration of the Composition fed to the centrifugal cleaners, or to the screens, or the effluent from each, is up to 2.5 wt.%, or up to 2 wt.%, or up to 1.5 wt.%, and is generally at least 0.2 wt.%, or at least 0.5 wt.% consistency.
  • the diluted stock is pumped by, for example, a fan pump 630 to one or more centrifugal cleaners 660 (to remove contaminants based on density), a pressure screen 670 (to remove large material), and then to the headbox 811. There is sometimes a secondary fan pump between the cleaners and screen to assist in pumping. After the pressure screen 760, the Composition enters a manifold where it is drawn off over the width of the paper machine into the headbox 811.
  • Centrifugal cleaners 660 or hydrocyclones, are used as a means of removing small contaminants and low-density fragments, such as plastics.
  • Centrifuges typically remove sand and grit, dirt, heavy and light contaminants. Unlike centrifuges, the separation in centrifugal cleaners is not induced by rotating the equipment, but by introducing the feed stream at relatively high velocity, tangentially via line 661 into a cylindrical body. This creates a vortex that tends to cause high-density components to move to the wall.
  • the lower portion of the cyclone consists of a convergent cone 66 (although this is not theoretically necessary). Material collected at the wall (the high-density fraction) is dis-charged from the bottom of the cone as rejects 663.
  • the bulk of the flow (the low-density fraction) forms an inner vortex that rises to the top of the unit and discharges through a central pipe 664 (the vortex finder) as a stream of accepts 665.
  • the accepts effluent 665 of the centrifugal cleaner 660 can be fed to a screen 670, generally a pressure screen or a rotating pressure screen.
  • the screen 670 can be effective to remove shives (fiber bundles) and other large, hard contaminants from the furnish separated by size.
  • Conventional pressure screens use baskets with either slots or holes to admit the fibrous
  • Slotted screens usually have a sculptured pattern that helps fibers to become aligned and pass through the screen.
  • Pressure screens are equipped with various types of rotors to continuously re-disperse any fibers that start to accumulate on the screen surface. Because fibers can pass through a slotted screen individually, but not as fiber floes, papermakers sometimes choose to add retention aids ahead of pressure screens in order to achieve a favorable balance of formation uniformity and adequate retention of fine particles.
  • compositions and wet laid articles as they proceed through the stock preparation zone 700 and the wet laid machine zone 800 are described in the following table 5.
  • the wire width, or the slice width, or the wet laid product width may vary from about 5 to 40 feet, or 10 feet to 40 feet, or 15 feet to 40 feet, and operate at speeds of at least 25 meters/minute (mpm), or at least 200 mpm, or at least 350 mpm, or at least 500 mpm, or at least 750 mpm, or at least 1000 mpm, or at least 1250 mpm, and up to 2200 mpm, or up to 2100 mpm, or up to 2000 mpm, or up to 1900 mpm. They may produce from 2 tons, or from 5 tons, or from 10 tons, or from 100 tons, or from 250 tons, or from 500 tons, and optionally up to 1200 tons per day of wet laid product.
  • the wet laid basis weight may vary from light tissue (about 10 grams per square meter) to paper board (up to 750 grams per square meter).
  • the Composition is fed to a manifold in a headbox where it is spread over and across the width of a slice in the headbox 811.
  • the Composition leaving the headbox 811 slice and deposited onto a continuous loop forming belt (or the wire) is formed into a web (or sheet) by draining the water from the Composition through the wire to form a wet fibrous mat called a wet web, which is then pressed, dried, and wound into a reel of paper on the wet laid machine.
  • the Composition is fed to a head-box zone 810 to evenly distribute and apply the Composition onto a moving endless wire.
  • the process includes feeding a Composition to the headbox in the wet end section of a wet laid machine, and the Composition contains cellulose fibers and CE staple fibers, optionally that have been co-refined, and the CE staple fibers have a DPF of less than 3, or a cut length of less than 6 mm, or crimping, or non-round with a DPF of less than 3, or a combination of any two or more of these characteristics.
  • the primary function of the headbox is to accept the low
  • the flow through the headbox nip and the wire speed are generally matched.
  • Other functions of the headbox can include providing velocity control of the jet leaving the headbox by the pressure in the headbox and breaking up pulp floes by turbulence within the headbox. These functions can be achieved by causing the stock Composition to flow through several rotating perforated rolls within the headbox or, in more modern headboxes, past stationary flow elements or weirs. After passing through these turbulence-generating elements, the stock is accelerated in a sharply converging orifice slit called a slice. On leaving the slice, the stock impinges upon the forming screen and quickly becomes a three-dimensional web when deposited onto the wire as the water drainage process commences.
  • the Composition is capable of remaining homogeneous with minimal or no visible segregation between the CE staple fibers and cellulose from the machine zone to the wire. This feature can be beneficial for any process in which the Composition can experience settling or non-turbulent conditions for a period of time.
  • the width of the slice is generally the same or slightly less (within 10%) than the width of the wire, and this is dependent on the types of machines employed.
  • the Composition leaving the Headbox Zone 810 is deposited onto a traveling wire in the Wire Zone 820.
  • the primary function of the Wire Zone 820 is to drain water from the Composition. Water drainage is generally accomplished by draining water from the Composition deposited onto the wire 821 traveling in the machine direction through gravity, vacuum, or both.
  • Wire Zone 820 is also known as the formation zone because here the water from the Composition drains through the wire 821 , and the fibers spread and interlace or consolidate on the wire to develop a wet sheet or wet web recognizable to the eye as a sheet or mat.
  • Wires may be divided into several types: Fourdrinier machines, twin-wire formers, and multi-ply formers, roto-formers, verti -formers, and delta-formers.
  • Fourdrinier machines twin-wire formers
  • multi-ply formers roto-formers
  • verti -formers roto-formers
  • delta-formers By far the most common type of paper machine in use today is Fourdrinier, although many modern facilities employ a roll blade gap former or verti-former or configuration in which the forming elements are vertically or not horizontally oriented.
  • the Composition can be employed on any wet laid machine, including any paper or paperboard making machine, for convenience the bulk of this disclosure will be with reference to the
  • the Fourdrinier table of a paper machine includes a forming wire
  • the Composition is deposited onto the wire 821 from the headbox zone 810, the water is generally first drained on the wire by gravity, and as it moves down the line in the machine direction, foil blades 822 under the wire assist in removal of water, along with an optional dandy roll 824 on top of the wire, as well as the application of vacuum to assist with further removal of water as the web moves in the machine direction.
  • the modern wire is actually a finely woven fabric on which the web is formed. Historically, these fabrics were made from bronze wire. Today most fabrics are made using woven synthetic fibers such as PET polymers fibers. Various types of weave are used to obtain maximum fabric life and to reduce wire marking on the wet sheet.
  • the foil blades 822 are located under the forming wire 821.
  • the foils 822 are angle and height adjustable.
  • the foils kiss the wire and remove some water through the Bernoulli effect.
  • the foil blade angle, height, and vacuum level are adjusted over the length of the wire, or dewatering table, until a paper dryness of a desired target is achieved. Without the foils, application of vacuum can prematurely cause the formation of a nonuniform web.
  • the moving web on the fabric passes over a series of suction/vacuum boxes 823 and then over a couch suction roll 825. Often, a dandy roll 824 is located on top of the forming fabric 821 before or over the vacuum boxes 823.
  • the dandy roll 824 is an open structured roll covered with wire cloth, resting lightly upon the surface of the web 828. Its function is to assist with removal of water, flatten the top surface of the sheet and improve the finish. A pattern on the dandy roll 824 may leave translucent patterns on the wet paper, in the form of names, insignia or designs, as watermarks.
  • the last roll in the forming section is called the couch roll 825. It is a suction roll to remove additional water and pass the sheet to the press felt in the Press Zone 830.
  • the initial paper dryness can be visually observed as the dry line 924, as shown in Figure 5.
  • the dry line 924 is the line of demarcation between the stock on the wire 821 that is submerged in water and the portion having fibers extending above the depth of the water.
  • the web before the dry line has a glossy look, and as the fibers extend above the water, a matte finish appears to create a line of demarcation is actually quite clear and visually observable with the naked eye as a line roughly perpendicular to the machine direction.
  • the dry line 924 is not a perfectly straight line and can be convoluted.
  • the dry line 924 is usually located a distance from the headbox down the machine direction of the wire and typically in the area of the vacuum boxes. If the dry line 924 is too far down the wire, not enough water has been removed and the sheet may not have enough strength to transfer from the couch roll 825 to the press rolls in press zone 830 without breaking.
  • the drainage rate of water is dramatically improved compared to a refined Composition with the 100% Cellulose Comparative composition.
  • This improvement in drainage rate provides one with a variety of process and/or product flexibility and options. For example, by using the co refined Composition, one can increase the line speed while retaining the same dry line location (increased throughput). Many production lines produce wet laid products on the order of tons per day, so even slight line speed increases result in substantially increased production.
  • the increase in line speed is particularly attractive if the machine configuration is dryer limited, or in other words, the line speed cannot be otherwise increased because the dryers are operating at maximum thermal energy output.
  • the line speed can be increased by 0.1 % or more, or by
  • the increase in line speed would be up to 25%, or up to 20%, or up to 15%, or up to 10%, or up to 8%.
  • the increase is relative to the line speed using the 100% Cellulose Comparative composition.
  • the dry line can be moved back toward the headbox without adjusting stock preparation or wet end machine settings by at least 2 inches, or at least 3 inches, or at least 4 inches, or at least 5 inches, or at least 6 inches, or at least 7 inches, or at least 8 inches, or at least 9 inches, or at least 10 inches, or at least 1 1 inches, or at least 12 inches, or at least 13 inches, or at least 14 inches relative to the location of the dry line location using the 100% Cellulose Comparative composition (the“Reference Dry Line”).
  • the perpendicular lines should be consistently drawn on both the Reference Dry Line and the actual Dry line. For example, if the perpendicular line crosses the point on the Reference Dry Line closest to the headbox 81 1 , then the perpendicular line crossing the actual Dry Line should also be at the point closest to the headbox, e.g. lines 925 and 922. Likewise, if the perpendicular line crosses the point on the Reference Dry Line farthest away from the headbox 811 , then the perpendicular line crossing the actual Dry Line should also be at the point farthest away from the headbox, e.g. lines 926 and 923.
  • the dry line should remain a distance of“y” from a line 921 parallel and co-extensive with the slice a location“C” on the headbox to the line drawn perpendicular to the MD of the wire intersecting the point on the actual Dry Line closest to the headbox 81 1 , e.g. line 922.
  • the distance“y” should be at least 1 foot, or at least 2 feet, or at least 2.5 feet, or at least 3 feet.
  • the improvement in drainage rate can also be achieved without the addition of additives for increasing the dewatering rate of pulp stock prior to introducing the Composition to the headbox 81 1.
  • additives are commonly known as drainage aids (also known as flocculants) and can be inorganic, organic, or biological. Drainage aids are usually low molecular weight water soluble polymers or resins that have a high cationic charge density, such as water-soluble cationic polymers prepared from
  • the drainage rate of the web made with the Composition can be increased without having to significantly change the zeta potential charge to the CE staple fibers, or any of the fibers, or of the Composition.
  • no additive is added to the Composition that changes the zeta potential of the CE staple fibers, all the fibers, or of the Composition by more than 4 mV, or by more than 3 mV, or by more than 2.5 mV, or by more than 2 mV, or by more than 1.5 mV or by more than 1 mV.
  • retention aids are highly charged, and the Composition need not contain a significant amount of a retention aid, or even no retention aid needs to be added to the Composition.
  • the change in zeta potential of the Composition fed to, in, or exiting the stuff box or to, in, or exiting the headbox 81 1 by the addition of any additive is desirably not more than 2 mV, or not more than 1 mV, or not more than 0.5 mV.
  • the zeta potential is a measure of the extent to which charged particles will interact with each other.
  • a fiber potential analyzer can be used and can be calculated according to the Helmholtz-Smoluchowski equation, and the reference to determine a change in the zeta potential is the Composition without the subject additive.
  • the consistency of the sheet comprising the Composition leaving the couch roll, or leaving the Wire Zone 820, or fed to the Press Zone 830 can range from 15 wt.% to 25 wt.%, or from 15 wt.% to 22 wt.%, or 18 wt.% to
  • twin wire and multi-ply formers were developed.
  • twin-wire formers the water from the stock is drained from both sides of the web between two wire fabrics, and twin wire formers can be horizontal or vertically oriented.
  • the twin wire machine can increase the dewatering rate of the stock and dewater from both sides, giving the resulting sheet more uniform properties throughout the thickness of the sheet.
  • Multi-ply formers are typically used in the production of paperboard.
  • the most common type are cylinder formers or cylinder mold machines that include a series of screen or mesh covered cylinders, each rotating in a vat of dilute paper stock. Web formation occurs on the screen as a result of suction inside the cylinder which removes the filtrate.
  • This technique provides a more random distribution of the fibers and are also used when processing a stock at higher consistencies. With higher consistencies, a more three-dimensional fiber orientation can be provided, resulting in higher thickness and stiffness in the machine direction. This technique is useful to make food packaging and consumer boxes such as those holding dry laundry detergent.
  • another Fourdrinier wire section can be mounted above a lower mounted Fourdrinier wire to allow for the manufacture of multi-layer paper and paperboard. These are called top formers and are typically used in multi-ply applications where one layer can be bleached and the other layer is unbleached.
  • the web or sheet can be formed between the wire and a special fabric as it wraps around a forming roll.
  • the web is continuously removed from the forming roll onto a large diameter dryer and peeled off with a doctor blade. This process is used to make tissue paper.
  • the sheet After the sheet leaves the Wire Zone 820, the sheet is taken up into the Press Zone 830 for further dewatering by pressing. In the Press Zone 830, the sheet undergoes compression to squeeze out more water from the sheet.
  • the pressing operation is considered a continuation of the wet end water removal. It is far lower in cost to remove water by mechanical means than by steam evaporation. Small increases in consistency leaving the press is one of the key ways to lower paper machine operating costs. Consistency can be increased if the ease of water removal can be improved from between sheet fibers and the transfer of the water from the sheet surface to the press felt(s).
  • the nip force can be expressed as pounds per lineal inch (“PLI”), and is calculate from the load applied on the opposing press rolls.
  • the operator can set the force on the loading of the opposing rolls against one another.
  • hydraulic pressure can be introduced into the hydraulic cylinder controlling a pivoting roll that presses against a fixed roll to generate the desired nip force between the fixed and pivoting rolls.
  • the PLI is a measurement expressed as the total force (in pounds) on the web in the z- direction (from top to bottom sides, compressive force) divided by the width (in inches) of the web.
  • the nip force can be 350 -550 PLI for newsprint and bond paper, and 400-6000 for corrugated paperboard and linerboard.
  • the press nip and hydraulic pressure applied to the press is limited by the ease of water drainage from the web. In a flow limited web, excess pressure applied to the web can result in crushing the sheet and blow outs because the water cannot escape from the web without destroying the web at the applied pressure. Slightly excessive pressures without web crushing or destruction can nevertheless result in washing fiber out and deposition onto the felt, or fiber realignment. However, a web made with the co-refined Composition has an improved ability to drain water.
  • an operator can take advantage of the higher draining capability of the Composition by increasing the press pressure, or decreasing the nip gap, while retaining the integrity of the web.
  • an increased level of water can be removed by the mechanical action of the press to provide a dryer web to the drying zone, thereby substantially reducing operating costs in the first and/or second drying zones.
  • the pressure on the web (PLI) at the press can be increased when a web containing the co-refined Composition is passed through the press rolls relative to the PLI tension that was or would be applied when a web made with either a 100% Cellulose Comparative composition or relative to any wet laid web passed through the press rolls immediately prior to passing the web containing the co-refined Composition through the press rolls.
  • the increase can be at least 2%, or at least 4%, or at least 5%, or at least 8%, or at least 10%, or at least 15%.
  • the increase can be at least 0.5%, or at least 1 %, or at least 1.5%, or at least 2%, or at least 4%, or at least 5%, or at least 8%, or at least 10%, or at least 15%.
  • the increase can be at least 0.5%, or at least 1 %, or at least 1.5%, or at least 2%, or at least 3%, or at least 5%, or at least 10%.
  • the second maximum load exceeds the first maximum load and the second applied load can exceed, be the same as, or be less than the first applied load.
  • the second applied load on the press rolls is higher than the first applied load.
  • the second maximum load is at least 0.5%, or at least 1 %, or at least 1.5%, or at least 2% higher, or at least 5% higher, or at least 10% higher, or at least 15% higher, or least 20% higher than first maximum load.
  • the press section mechanically squeezes water from the wet web between rolls to one or more felts, thereby increasing the consistency of the web, and also reduces the bulk or thickness of the web.
  • the press felts aid in supporting the web sheet and absorbing the water pressed from the web. This compaction assists in subsequent consolidation and bonding of fibers. Sheet consolidation and fiber bonding in the press section helps bond the web.
  • the material for the press felt if a felt is used, is not limited, and can include wool or synthetic materials such as polyamide woven fabrics having a thick batt to absorb more water.
  • the rolls can be single (one roll) felted or double felted (both rolls felted).
  • a single felted configuration typically employs a smooth top roll and a bottom felted roll which would make the top side appear smoother.
  • Double felted rolls impart a rougher appearance to both sides of the sheet.
  • the press rolls can be simple with a smooth or texturized surface, or the rolls can be vacuum rolls made of metal and covered with a synthetic material or rubber with a vacuum in the core of the roll.
  • the felts are on a continuous loop and will pass through the nip of the rolls.
  • the felt absorbs water from the sheet as water is squeezed from the sheet through the compression forces applied by the rolls.
  • the felt continues its run through a vacuum system/uhle boxes to remove moisture from the felt and continues around returning through the roll nips ready to absorb moisture from the sheet.
  • the felt is a continuous belt loop so that at all times, water from the sheet passing through the roll nip is absorbed onto the felt.
  • extended nip presses can be used, which employ a larger composite covered roll on the bottom to extend the residence time of the sheet between the rolls and increasing the dewatering of the sheet.
  • the consistency of the sheet leaving the Press Zone 830 can be increased by 20% or more, e.g. from at least 35% with
  • the extent of water removal from the sheet in the Press Zone 830 depends on the line speed and the compression between the press rolls and the condition of the press felts.
  • the web entering the press zone can have a consistency of 15 wt.% to 25 wt.%.
  • the web upon pressing or leaving the Press Zone 830 can have a consistency of 35 wt.% to 80 wt.%, or from 40 wt.% to 70 wt.%, or from 40 wt.% to 60 wt.%, or from 40 to 55 wt.%, or from 40 to 50 wt.%.
  • Dry End of Machine Zone First Drying Zone
  • the sheet leaves the Press Zone 830 and the First Drying Zone 840 at a consistency noted above.
  • the sheet leaving the First Drying Zone 840 can have a moisture of 5% or less by weight.
  • the dryer causes further water removal from the sheet by evaporation.
  • a typical dryer section consists of from 10 to 70 steam-heated dryer cylinders.
  • the sheet may be held in intimate contact with the heated surfaces by means of dryer felts.
  • the first drying zone 840 begins the“dry-end” of a paper making process.
  • the dry end of the paper making machine typically includes first drying section, optionally a size press, an optional second drying section, a calender, and "jumbo" reels, while the wet end of the paper making machine typically includes the headbox, the wire section, and the presses.
  • the First Drying Zone 840 includes a heating element.
  • a heating element is an internal steam heated cylinder that evaporates the moisture from the sheet.
  • the First Drying Zone includes multiple steam heated cylinders, including at least 10, or at least 20, or at least 40, and can range from 10 to 80 or 20-70 or 40-70 dryer cylinders.
  • the sheet is held in intimate contact with the heated surfaces by means of dryer felts.
  • a dryer felt presses the sheet against the dryer rolls. Humidity is removed from dryer felt using pocket and hood ventilation (forced air removal). Dryer fabric permeability can impact the rate of water removal.
  • suitable outer shell cylinder temperatures are within a range from 100°C to 140°C.
  • the wet laid web can be heated to in the First Dryer Zone and Second Dryer Zone to a maximum sheet temperature in excess 90 °C, or at least 95 °C, and up to 100°C. Since drying zones contain a continuum of cylinder temperatures corresponding to the desired heat up, maintenance, and optional cool down profiles, the maximum sheet
  • temperature is the maximum temperature reached within drying zone.
  • Steam pressures within the cylinder can be at least 10 psig, or at least 20 psig, and generally reach up to 100 psig. Suitable steam pressure for many designs is between 20 to 90 psig.
  • the dryer section is the most expensive part of a paper machine in the terms of capital cost and operational cost.
  • the First and Second Dryer Zones remove a smaller quantity of water compared to the amount of water removed on the Wire Zone 820 and the Press Zone 830. A value of 1.3 kg steam per 1 kg of water evaporated is typical for modern paper machine.
  • the operational costs for removing water from the sheet in the dryer zones can run between 70-80% of the total cost for removing water, and the capital costs of the dryer section are the highest on the line. Thus, lowering the energy demand and usage in the dryer section can result in significantly overall lowered production and/or capital costs.
  • the sheet leaving the Press Zone 830 passes through one or more, or 6 or more, or 8 or more, or 10 or more, or 14 or more rotating heated (typically through steam) metal cylinders to evaporate moisture from the sheet and withdraw the moisture through a ventilation system.
  • the cylinders can be divided into groups (or sections) of 2 or more, typically 4-8, with each group having its own drive system to allow for tension adjustments between each group to account for sheet shrinkage as water evaporates from the sheet in the machine direction.
  • the groups can be progressively run at slower rotational speeds in the machine direction to account for the shrinkage that occurs as the sheet moves through the First Dryer Zone 840.
  • the cylinder configuration can be single or double tiered (two rows of cylinders), desirably double tiered.
  • the cylinders can be felted as single sided felts (only one sheet surface contacts the felt) or double sided where both sheet surfaces contact the felt.
  • the configuration is double tiered, and the cylinders are single felted with each group of cylinders alternating the side on which the sheet contacts the felt.
  • the felt material is not limited. It is typically made of coarse threads and have an open weave to improve heat transfer.
  • the first one or more cylinders in the First and Second Drying Zones 840 and 860 can be unfelted to allow broke to fall onto the floor basement or catch basin, and to assist with threading a new sheet.
  • the most common method for applying thermal energy is the use of steam, with the surface of the cylinder rolls as the heat transfer medium.
  • the cylinder drying method also provided a good support and smoothness to the sheet as it advances forward at high speeds.
  • the material of construction for the shell of the cylinders is desirably one which has a high thermal
  • the shell thickness will depend on the desired steam pressure ratings. Suitable drying cylinder diameters range from 3 feet to 9 feet, or from 4.5 feet to 6.5 feet, with a shell thickness of 1 ⁇ 2” to
  • the heat from steam introduced into the cylinder is released by heat transfer to the cylinder shell and resulting condensation.
  • a difference of 10°C to 25 °C between steam temperature entering the cylinder at operating pressures and the exterior shell surface temperature, for at least two or more cylinders and desirably at least 70% of the cylinders, is generally within acceptable limits.
  • the condensate in the cylinder is continuously removed to allow for effective heat transfer to the cylinder shell surfaces and to the sheet.
  • the rotation of the cylinder is sufficiently fast to cause the condensate to contact the internal walls of the shell through centrifugal forces.
  • the speed of cylinder rotation desirably meets or exceeds the rimming speed of the condensate within the cylinder for more uniform heat transfer to the shell.
  • Turbulence within the cylinder can also be increased by installation of weirs or turbulence generating bars within the shell in order to improve heat transfer.
  • the condensate and any uncondensed steam can be siphoned from the cylinder and sent to a separator tank or steam trap to separate condensate from steam as low- pressure steam is returned to the boiler section compressors or reboiler or vented.
  • the operator has the flexibility to increase line speed beyond the line speed limited by drying capacity, or a reduction in the steam enthalpy delta (e.g. by reducing pressure drop and/or internal energy changes).
  • the co-refined Composition has a high drainage rate, thereby allowing improved dewatering at the wet end of the machine line through the wire and press zones.
  • a sheet containing the co-refined Composition can contain less moisture entering the First Drying Zone 840, thereby reducing the quantity of moisture that needs to be removed from the sheet in the First Drying Zone 840 to achieve the same dryness target existing the First Drying Zone 840.
  • sheets made with the co-refined Composition have greater permeability, thereby facilitating not only the mass transfer of water from the sheet through gravity and compression, but can also improve evaporation rates of internal moisture captured under the surfaces of the sheet, such as moisture closer to the core of the sheet, as well as surface moisture.
  • the temperature profile of the First Drying Zone 840 can be adjusted as illustrated in Figure 6.
  • the web entering a drying zone cannot come into contact with drying cylinders at the maximum drying temperature. Rather, the web temperature is ramped up over time to a maximum temperature with successively higher drying cylinder temperatures, known as a warm up time or pre-heat time.
  • Slope 1 is a curve representing the drying profile of a web made with a 100% Cellulose Comparative composition in which the web, in which progressively increasing temperatures are applied to the web through at least a portion of the First Drying Zone 840 as it moves the MD over time as represented on the x axis.
  • Each block increase in temperature represents the temperature increase in successive drying cylinders as the web moves down the line until a maximum drying cylinder temperature C is reached after which the cylinder temperature is no longer increased.
  • the ramp up to the maximum cylinder temperature is the pre-heat phase.
  • Option a) is graphically depicted as Slope 2, in which the
  • Slope 2 is an example of a constant increase in temperature at a steeper slope than Slope 1.
  • the y intercept can be increased.
  • the operator has the option of turning off steam delivery to one or more drying cylinders, thereby saving energy costs.
  • a wet laid process in which steam delivery to one or more drying cylinders in a First Drying Zone is discontinued upon or during processing a web containing or obtained with the Composition.
  • operation of a drying cylinder in a constant evaporation rate zone is discontinued because this is the zone where the cylinders operate the hottest or within 5% of the hottest cylinder.
  • the number of drying cylinders operating at a constant or maximum temperature is increased upon or during
  • a process for increasing the line speed of a sheet moving through a first drying zone 840 in a paper machine by passing a web made with a Composition without the co-refined Composition through a drying zone at a first line speed to obtain a first target dryness, and subsequently passing a web containing the co-refined Composition through the same drying zone at a second line speed to reach or exceed the first target dryness, wherein the second line speed is greater than the first line speed.
  • the second line speed can be operated for at least a day, or at least two consecutive days, or at least 1 consecutive week, or at least 2 consecutive weeks.
  • the second speed can be at least 0.1 %, or at least 0.5%, or at least 1 %, or at least 2%, or at least 3%, or at least 5%, or at least 8%, or least 10% faster than the first line speed.
  • the process includes increasing line speed by processing a web containing the Composition, determining the drop in the level of dryness relative to a target level of dryness, and increasing the line speed to a new line speed to reach the target level of dryness, and thereafter operating at the new line speed.
  • the second line speed can be operated for at least a day, or at least two consecutive days, or at least 1 consecutive week, or at least 2 consecutive weeks.
  • the maximum theoretical line speed would be limited by the temperature profile set without blowing out, blistering, tearing or otherwise damaging the sheet properties.
  • the increase in line speed can be at least 1 %, or at least 2%, or at least 3%, or at least 5%, or at least 8%, or least 10%, and up to 25%, or up to 20%, or up to 15% faster than the maximum
  • the mass per unit time of the web in the First or Second Drying Zones 840 or 860 can be increased by either increasing the line speed or increasing the basis weight, or both. With the improvement is evaporation of water out of the interior of the web, now the basis weight can also be increased if desired for a particular application.
  • a wet laid process in which a web containing or obtained from the Composition is passed through a drying zone at a mass/unit time that is greater than the mass/unit time of a web passed through the drying zone prior to the web containing or obtained by the Composition, for the same end application.
  • the increase can be at least 0.1 %, or at least 0.2%, or at least 0.3%, or at least 0.5%, or at least 0.8%, or at least 1 %, or at least 1.4%, or at least 1.7%, or at least 2%, or at least 2.5%/. Additionally, or in the alternative, the increase attributable to an increase in line speed can be up to 25%, or up to 20%, or up to 15%, or up to 10%, or up to 7%, or up to
  • Any conventional dryer ventilation system can be employed.
  • the dryer groups can be enclosed with a ventilation system to conserve heat.
  • ventilation system is pocket ventilation, which heated air usually supplied to the sheet in the pockets between the cylinders to increase the rate of drying.
  • the ventilation system assists with the removal of evaporated moisture and therefore is an important driving force for the efficiency of evaporation.
  • the efficiency of the ventilation system can be more effective to increase the rate of evaporation than raising the surface temperature of the cylinder shells.
  • the ventilation system can remove evaporated moisture by circulating hot dry air through the pockets of moisture.
  • Such pocket ventilation can be delivered through perforated or slotted tubes along their entire length that face into the pocket.
  • the ventilation system can also control the ambient humidity and reduce humidity variation along the dryer line.
  • a good ventilation system can save costs on drying energy and improve the drying rate.
  • a dryer hood can be employed in the space above the dyer section of the paper machine to withdraw the moist air.
  • the length of the hood can commence from the end of the presses to the beginning of the reel take up.
  • An infra-red system can be used in conjunction with steam cylinder heating.
  • the infra-red system is useful to place toward the end of the first or second dryer zone to dry moisture streaks in the sheet or to flatten a moisture profile across the sheet.
  • the Press Zone 830 or the beginning of the Drying Zone 840 can also include a water spray or a steam shower to deposit a controlled amount of moisture to the sheet and create a more uniform moisture profile as the sheet travels through the drying elements. A more uniform moisture profile can minimize the formation of curl, cockle, and moisture streaks.
  • the sheet dried in the First Drying Zone 840 can be fed into a
  • the size press is desirably located between the First and Second Drying Zones 840 and 860, although it can alternatively be located before the calendering zone.
  • the purpose of the sizing press applying surface sizing agents to the sheet are to alter the sheet’s resistance to water and/or ink penetration, improve its smoothness, reduce
  • Sizing agents can be internal when applied in the wet end, such as in the Second Blending Zone 740, or external when applied in the dry end, and such sizing agents are known as surface sizing. Many of the internal sizing agents can be applied as surface sizing agents, and many of the surface sizing agents can also be applied as internal sizing agents.
  • the sizing agents are generally applied with a sizing press.
  • a sizing press An example of suitable size presses includes roll applicators passing the sheet through a flooded nip between two rolls. Alternatively, size presses can transfer a film from the roll to the sheet after passing the roll through a bath.
  • the size press can be horizontal, vertical, or angled with respect to the orientation of the sheet as it passed through the nip.
  • the sizing agents can be used for hard-sizing, slack-sizing, or both methods of sizing.
  • Some size presses also include a coater which applies a coating to the web surface. If a coating is applied, it can be performed in the Sizing Press Zone 850 or in the Finishing Zone 870, before or after winding onto a reel.
  • Coating is a process by which paper or board is coated with a layer containing an agent to improve brightness, opacity, smoothness, printability, and color properties. The coating fills the miniscule pits between the fibers in the base paper, giving it a smooth, flat surface, which can improve the opacity, luster and color-absorption ability. Coating means that a layer is applied to the paper, either directly on the papermaking machine or separately (off machine coating).
  • Suitable coating devices and methods include an air knife coater, curtain coater, slide lip coater, die coater, blade coater, Bill blade coater, short dwell blade coater, gate roll coater, film transfer coater, bar coater, rod coater, roll coater and size press.
  • an air knife process an air jet impinges the web acting like a doctor blade to remove excess coating applied to the web.
  • a flexible doctor blade set to the desired angle removes excess coating across the web. The various blades and rollers ensure the uniform application of the coating.
  • the coating contains one or a mix of agents such as pigments and binders.
  • agents such as pigments and binders.
  • a type of coating can include fillers such as calcium carbonate, PCC, china clay, and/or chalk, optionally suspended in a binder.
  • a binder is a chemical compound or polymer that adheres wet laid fibers together or adheres the CE Staple fibers to the pulp fibers, or is an adhesive.
  • the binder is typically a liquid at 25 °C and 1 atm.
  • Suitable binders include water-dispersible binders and water-soluble binders.
  • water-dispersible binders examples include latexes, conjugated diene-based copolymer latex such as styrene-butadiene copolymer or acrylonitrile-butadiene copolymer (optionally mixed with starch), acrylic-based copolymer latex such as polymers of acrylic acid esters or methacrylic acid esters or methyl methacrylate-butadiene copolymer, vinyl-based copolymer latex such as ethylene-vinyl acetate copolymer or vinyl chloride-vinyl acetate copolymer, polyurethane resin latex, alkyd resin latex, unsaturated polyester resin latex, functional group-modified copolymer latex of these various polymers modified with a carboxyl group or other functional group-containing monomer, and thermosetting synthetic resins such as melamine resin or urea resin.
  • conjugated diene-based copolymer latex such as styrene-butadiene cop
  • water-soluble binders examples include starch derivatives such as oxidized starch, etherified starch or starch phosphate, cellulose derivatives such as methyl cellulose, carboxymethyl cellulose or hydroxyethyl cellulose, polyvinyl acetate, polyvinyl alcohol and polyvinyl alcohol derivatives such as silanol-modified polyvinyl alcohol, natural polymer resins and derivatives thereof such as casein, gelatin or modified gelatin, soybean protein, pullulan, gum arabic, karaya gum or albumin, vinyl polymers such as sodium
  • polyacrylate sodium alginate, polypropylene glycol, polyethylene glycol, maleic anhydride and copolymers thereof.
  • the binder employed is not one that is capable of imparting hydrolyzability to the wet laid product or sheet.
  • binders are the alkali metal salts of water- soluble anionic polymers or alkali metal salts of hydroxides and can surface hydrolyze the CE staple fibers, whether in the composition, wet laid product or sheet.
  • binders that surface hydrolyze the CE Staple fibers are the alkali metal salts of polysaccharides including those having a functional group such carboxyl or sulfonic groups such as sulfates (such as alkyl celluloses such as carboxymethyl cellulose and carboxymethyl ethyl cellulose, carboxymethyl starch, and alginic acid; those having a sulfonic group such as chondroitin sulfate); and polyacrylic acid.
  • sulfates such as alkyl celluloses such as carboxymethyl cellulose and carboxymethyl ethyl cellulose, carboxymethyl starch, and alginic acid; those having a sulfonic group such as chondroitin sulfate
  • polyacrylic acid e.g.
  • alkali metal salts of water soluble anionic polymers or alkali metal hydroxides are added to the Compositions or in the process; or the Compositions, processes, and wet laid products do not contain more than, 1 wt.%, or more than 0.5 wt.%, or more than 0.1 wt.%, or more than 0.05 wt.%, or more than 0.01 wt.%, or more than 0.005 wt.%, or more than 0.001 wt.%, or more than 0.0005 wt.%, or do not contain any such surface hydrolyzing binder, or have no such binder added.
  • the Composition, processes described herein, and wet laid articles including paper contain a low alkali metal content, such as not more than not more than 2 mitioI, or not more than 1.75 mitioI, or not more than 1 5mitioI, or not more than 1.25 mitioI, or not more than 1 mitioI, or not more than 0.75 mitioI, or not more than 0.5 mitioI, or not more than 0.25 mitioI, or not more than 0.15 mitioI, or not more than 0.1 mitioI in each case per gram of composition or wet laid product such as paper.
  • a low alkali metal content such as not more than not more than 2 mitioI, or not more than 1.75 mitioI, or not more than 1 5mitioI, or not more than 1.25 mitioI, or not more than 1 mitioI, or not more than 0.75 mitioI, or not more than 0.5 mitioI, or not more than 0.25 mitioI,
  • the amount of synthetic binder particles is less than 5 wt.%, or not more than 4.5 wt.%, or not more than 4 wt.%, or not more than 3.5 wt.%, or not more than 3 wt.%, or not more than 2.5 wt.%, or not more than 2 wt.%, or not more than 1.5 wt.%, or not more than 1 wt.%, or not more than 0.5 wt.%, or not more than 0.25 wt.%, based on the weight of all fibers in the Composition.
  • the Composition does not contain any added binder, or no binders are added to the Composition or added in the process of making a wet laid product.
  • Uncoated paper is typically used for letterheads, copy paper, or printing paper. Most types of uncoated paper are surface sized to improve their strength. Such paper is used in stationery and lower quality leaflets and brochures.
  • the sheet is rewetted with the sizing agents and consequently, the sheet exiting the sizing press typically has a moisture content of 10% to 60%, or 20% to 60%, or 30% to 60%. Since the sheet under tension moving at high speeds is re-wetted, sheet breaks at the sizing press are common, particularly if there is a weak spot in the sheet. Size presses that utilize the puddling method of applying the sizing agent, that is, flooding the sheet with the sizing agents through the nip of the size rolls, tend to increase the risk of sheet breakage.
  • a coating or film-applicator type of size press in which the sizing agent is metered onto a transfer roll by a blade, smooth roll, or a grooved roll, and the sizing agent is applied to the sheet upon contact with the transfer roll.
  • One of the variables that can be controlled to reduce the risk of sheet breakage at the size press is to employ a sheet having good dry- strength.
  • a synthetic fiber is added to cellulose fibers, the dry strength, or tensile strength of the dry sheet, will deteriorate.
  • sheets containing or made with the co-refined Compositions have improved dry tensile strength over corresponding sheets made with same CE staple fibers added after refining the cellulose fibers and have improved dry strength over sheets made with many of other types of synthetic fibers without binders added to the cellulose fibers after refining the cellulose fibers.
  • Such synthetic fibers include PET, polypropylene, and acrylics.
  • Zone 740 can also be applied as external sizing agents. These include brightening agents, dyes, pigments, antimicrobial agents, starches, and adhesives mentioned above as additives in the Second Blending Zone 740. Examples of different types of sheet products using particular sizing agents include starch applied to linerboards to improve the stiffness and strength of boxes; pigments and binders applied to sheet for magazines and newsprint and printer paper to enhance printability; and a variety of coatings and polymers applied to sheet used for packaging and containers to alter their water resistance and strength.
  • pigments include the inorganic and organic pigments described above that can be added to the Second Blending Zone 740.
  • Starch is a common external sizing agent and has many uses in papermaking. For example, it functions as a retention agent, dry-strength agent and surface sizing agent.
  • Starches can be virgin or modified. Virgin starches include but are not limited to amylose, amylopectin, and mixtures thereof such as 25% amylose and 75% amylopectin (corn starch) and 20% amylose and 80% amylopectin (potato starch). The virgin starches can be obtained from potatos, wheat, corn, rice, or tapioca.
  • Modified starches include oxidized starch; starch esters; starch ethers; enzymatically treated starches; hydrolyzed starches; heated starches, also known in the art as “pasted starches”; cationic starches, such as those resulting from the reaction of a starch with a tertiary amine to form a quaternary ammonium salt; anionic starches such as the phosphate starches; ampholytic starches (containing both cationic and anionic functionalities); cellulose and cellulose derived compounds; and combinations of these compounds
  • Sizing agents which improve the sheet strength include natural polymers or semi-synthetic polymers such as starch, either in its native or chemically modified form, and synthetic polymers such as copolymers of acrylamide.
  • suitable sizing agents include starches (oxidized, mill modified) including the cationic and amphoteric starches; poly vinyl alcohol (PVA); polyacrylamide (PAM); polyamido polyamine polymers, further reacted with epichlorohydrin; cationic starches or amphoteric starches;
  • anionic polymers such as a polyacrylic acid, copolymers of acrylamide and acrylic acid, and carboxymethyl cellulose
  • cationic polymers such as a cross- linked polyamidoamines, polydiallyldimethylammonium chlorides, linear or branched polyamines, polyethyleneimines, fully or partially hydrolyzed polyvinylamines, copolymers of diallyldimethylammonium chloride and acrylamide, copolymers of 2-acryloylethyltrimethyl-ammonium chloride and acrylamide, cationic guar and other natural gum
  • polymeric aldehyde- functional compounds such as glyoxalated polyacrylamides, aldehyde celluloses and aldehyde functional polysaccharides
  • amphoteric polymers such as terpolymers of acrylamide, acrylic acid, and diallyldimethylammonium chloride, or acrylamide, acrylic acid, and 2-acryloylethyltrimethylammonium
  • sizing agents to control the penetration of ink or moisture into the paper product, or its hydrophobicity include rosin; rosin precipitated with alumina; maleic anhydride; abietic acid and abietic acid homologues such as neoabietic acid and levopimaric acid; stearic acid and stearic acid derivatives; ammonium zirconium carbonate; silicone and silicone-containing compounds, such as RE-29 available from GE-OS1 and SM-8715, available from Dow Corning Corporation (Midland, Mich.); fluorochemicals of the general structure CF3(CF2)nR, wherein R is anionic, cationic or another functional group, such as Gortex; alkylketene dimer (AKD), such as Aquapel 364, Aquapel (I 752, Fleron) 70, Flercon 79, Precise 787, Precise 2000, and Precise 3000, all of which are commercially available from Flercules,
  • CMC carboxymethylcellulose
  • polyvinyl alcohol polyvinyl alcohol
  • methyl cellulose alginates
  • waxes wax emulsions
  • combinations of such sizing agents
  • the sizing agent may be added to the sheet in the form of a dispersion, an emulsion or a suspension, desirably oil-free.
  • the process desirably includes a Second Drying Zone 960, particularly when a Sizing Press Zone 850 is employed because the sizing press applies moisture to the sheet in an amount sufficient to increase the moisture substantially.
  • the Second Drying Zone 860 can incorporate one or more or all of the features of the First Drying Zone 840.
  • the moisture of the web in and exiting the Second Drying Zone is from 2% to 10%, desirably from 5 wt.% to 8 wt.%.
  • the sheet can optionally be further processed in a Finishing Zone 870.
  • Typical sheet moisture entering the Finishing Zone 870 ranges from 2% to 10%, or 5% to 8%.
  • the Finishing Zone can include one or more of a calendering zone, reel zone, rewinding zone, and coating zone.
  • a calendering zone the web can be passed through machine calender stack. This stack, optionally a vertical stack, of steel on steel or steel on polymer rolls impart successively higher compression cycles to the paper as the paper passes through the rolls. Normally a dry paper sheet is calendered. The function of the calender stack is to reduce the thickness and to impart a smooth surface to the paper web for good printability. This deformation can be enhanced using heat and moisture.
  • the paper web is wound into a large roll at the end of the paper machine, called a jumbo roll.
  • the calendering and reeling operations are the last part of the continuous paper machine.
  • the jumbo roll reaches its target weight, the paper is transferred onto a new spool in a continuous mode without machine shut down.
  • the jumbo roll In a rewinding zone, the jumbo roll is transferred to a winder where it is unwound and slit into smaller rolls (Master Rolls) based on customer specifications. In most mills, the rolls then go to a wrapping station, and then into storage.
  • Master Rolls smaller rolls
  • an off-machine super-calender can be employed. This is done primarily for magazines and coated papers.
  • the paper passes through rollers, which are alternately hard and soft.
  • the paper acquires a high luster surface.
  • the paper becomes somewhat compressed during the process and is therefore thinner than its matte finished equivalent.
  • One or more enhancements are provided by the manufacture of wet laid webs containing the co-refined Compositions. These are described in further detail. The measurement of any reference to a property of the
  • Composition or wet laid products containing or obtained by the Composition throughout this description is determined by the relevant test method referenced in Tables 8 & 9. To obtain a value for a test method of interest, an average of 5 wet laid sheets (not 5 samples from one product) are tested by the relevant test method, except that when a Cobb size or Mean Flow Pore Size method is employed, only 2 wet laid sheets are tested.
  • Bond, copy paper, ledger paper and rag paper have a basic sheet size of 17 x 22 inches.
  • Cover stock has a basic sheet size of 20 x 26 inches.
  • Tag stock has a basic sheet size of 24 x 36 inches.
  • Index stock has a basic sheet size of 25.5 x 30.5 inches.
  • the basis weight of the wet laid products containing or obtained by the Composition is not limited. Examples include a basis weight of at least
  • a wet laid web having a density decrease relative to a wet laid web made with a 100% Cellulose Comparative composition at the same basis weight.
  • the density decrease can be at least 2%, or at least 3%, or at least 4%, or at least 8%, or at least 9%, or at least 10%, or at least 13%, or at least 15%, or at least 20%, or at least 25%, and can be quite high.
  • the density decrease can be higher than 60%, and even higher than 80% depending on how much CE staple fiber is co-refined. For many applications, the density decrease is suitably up to 50% or up to 40%.
  • a wet laid web having a density decrease while maintaining or improving Gurley Stiffness, relative to a wet laid web made with a 100% Cellulose Comparative composition at the same basis weight is attractive for paperboard applications where maintaining stiffness is an important consideration.
  • the density decrease can be as mentioned above.
  • the wet laid product can be light-weighted by decreasing the basis weight at the same thickness.
  • the basis weight decrease can be at least 0.5%, or at least 1 %, or at least 2%, or at least 3%, or at least 4%, or at least 5%, or at least 6%.
  • the basis weight decrease can be as high as 20%. In general, the basis weight decrease can be up to 20%, or up to 15%, or up to 12%, or up to 10%, or up to 8%, or up to 6%.
  • a wet laid web having a basis weight decrease while maintaining thickness and maintaining or improving Gurley Stiffness, relative to a wet laid web made with a 100% Cellulose Comparative composition having a basis weight necessary to obtain the same Gurley Stiffness and thickness there is also provided a wet laid process in which a wet laid web, having a given basis weight, is made that has a target Gurley stiffness and thickness, and modifying the process to reduce the basis weight of the wet laid product to have the same, better, or no more than a 5% reduction in the same target Gurley stiffness and be within +/- 5% of the same target thickness.
  • one or more additional properties can be maintained or improved, including opacity as measured by TAPPI T-425, tear strength, and/or air and/or liquid permeability.
  • the wet laid products containing or obtained from the co-refined Compositions result in products having increased thickness at the same basis weight, and with increased thickness, the product will have an improved R- value of insulation, reduced heat transfer applications, reduced sound transfer, its compressibility, and/or embossing performance.
  • a wet laid product made with the co-refined Composition have a higher insulation R-value than a wet laid product made with a 100% Cellulose Comparative composition at the same basis weight.
  • the insulation value increase can be at least 2% higher, or at least 5% higher, or at least 8% higher, or at least 10% higher.
  • wet laid products for which higher insulation values are desirable include food packaging boxes such as hot meal delivery boxes, e.g. pizza boxes, and other hot and cold food boxes, and medical packaging to maintain cool temperatures.
  • Such boxes can optionally be lined with insulating material or additional corrugated paperboard as a liner.
  • the wet laid products containing or obtained by the Composition have improved air permeability.
  • Increased air permeability can have a number of advantages, including improved water drainage, improved evaporation rate from the interior of the web, reduced pressure drop across filter media, faster web machine line speeds, lower residence time of contaminants contacting the fibers such as in an de-inking cell, food
  • Air permeability is measured by TAPPI 251 in units of l/min/cm2/bar and ft3/ft2/min.
  • the air permeability of the wet laid products containing or obtained by the Composition is at least 1.2, or at least 1.3, or at least 1.4, or at least 1.5, or at least 1.7, or at least 2.0, or at least 3, or at least 4, or at least 5 ft3/ft2/minute by the TexTest.
  • the Gurley Permeability of the wet laid products containing or obtained by the Composition can be at least 100, or at least 200, or at least 300, or at least 400, or at least 500, or at least 600, or at least 700, or at least 1000, or at least 2000, or at least 3000 l/min/cm2/bar and at basis weights of at least 30 g/m2, or even at basis weights of at least 40 g/m2, or even at basis weights of at least 50 g/m2, or even at basis weights of at least 60 g/m2, or even at basis weights of at least 70 g/m2, or even at basis weights of at least 80 g/m2, or even at basis weights of at least 90 g/m2, or even at basis weights of at least 100 g/m2, or even at basis weights of at least 1 10 g/m2, or even at basis weights of at least 120 g/m2, or even at basis weights of at least
  • the air permeability of the wet laid products containing or obtained from the co-refined Composition is increased by at least 5%, or at least 7%, or at least 9% or at least 10%, or at least 13%, or at least 15%, or at least 20%, or at least 25%, or at least 50%, or at least 75%, or at least 100%, or at least 150%, or at least 200%, relative to a 100% Cellulose Comparative composition.
  • the wet laid products containing or obtained by the Composition can be made with a low mean flow pore size.
  • the wet laid products can have a mean flow pore size of 20 or less, or 15 or less, or 12 or less, or 10 microns or less, or 8 microns or less, or 6 microns or less or 4 or less, or 2 microns or less, or 1.5 microns or less, or
  • 1.4 microns or less or 1.3 microns or less, or 1.25 microns or less, or 1.20 microns or less, or 1.1 microns or less, or 1 micron or less, or 0.8 microns or less.
  • the porosity is measured on a Porometer by the ASTM F-316 test method.
  • Useful products with low pore size include filtrations applications for gas and liquid, such as surgical face masks, air filters, air depth filtration, disposable clothing for excluding biological agents, liquid filtration for size exclusion, filter presses, high pressure liquid depth filtration, coffee filters, each used in the home consumer and industrial markets.
  • the wet laid products containing or obtained by the Composition can have low mean flow pore size with increased air permeability.
  • a smaller pore size can be achieved by calendering, wet pressing, breaker stack, or any other suitable press method, or with the use of binders, or both. While one would expect lower air permeability with reduced mean flow pore size, the wet laid products, including paper products, containing or obtained by the Composition can have increased permeability (either air and/or liquid) with the same or lower pore size, or at a given pore size, relative to a 100% Cellulose Comparative composition.
  • This feature provides one with the ability to improve on a large variety of end use applications where vapor and/or air permeability combined with size exclusion is desired.
  • Such applications include, for example, surgical or dust masks to both minimize fogging and enhance breathability while excluding many harmful bacteria with the small pore size; high air permeable gas filters; high air permeable wet laid products and especially wet laid non-woven products such as clothing (e.g. jump suits, shirts, and pants) to reduce heat build-up by the wearer while also excluding entry of harmful particles; and food packaging which requires good air permeability while excluding many bacteria.
  • the ratio of mean flow pore size to air permeability can be at less than 1.20, or no more than 1.15, or no more than 1.10, or no more than 1.05, or no more than 1.00, or no more than 0.95, or no more than 0.90, or no more than 0.85, or no more than 0.80, or no more than 0.75, or no more than 0.70, or no more than 0.65, or no more than 0.60, or no more than 0.55, or less than 0.4, or not more than 0.35, or not more than 0.3, where the units of air permeability are (l/min/cm2/bar) and for mean flow pore size are microns.
  • wet laid products having a mean flow pore size of less than 2 microns, or not more than 1.7 microns, or not more than 1.5 microns, or not more 1.3 microns can have a ratio of mean flow pore size to air permeability of less than 1.20, or no more than 1.15, or no more than 1.10, or no more than 1.05, or no more than 1.00, or no more than 0.95, or no more than 0.90, or no more than 0.85, or no more than 0.80, or no more than 0.75, or no more than 0.70, or no more than 0.65, or no more than 0.60, or no more than 0.55, where the units of air permeability are (l/min/cm2/bar) and the units of mean flow pore size are microns.
  • wet laid products having a mean flow pore size of 2 microns or more, or 2.5 microns or more, or 3 microns or more can have a ratio of mean flow pore size to air permeability of less than 0.4, or no more than 0.38, or no more than 0.35, or no more than 0.3, or no more than 0.25, or no more than 0.20, or no more than 0.15, or no more than 0.125, or no more than 0.10, where the units of air permeability are (l/min/cm2/bar) and the units of mean flow pore size are microns.
  • the wet laid web product has an air permeability of at least 200 l/min/cm2/bar and a mean flow pore size of less than 20 microns, or less than 10 microns on a wet laid product having a density within a range of 0.342 to 0.602 g/cm3.
  • an air filter having an increased air flow at a constant pressure drop relative to a 100% Cellulose Comparative composition at the same basis weight.
  • the air filter can have an increase air flow of at least 25%, or at least 50%, or at least 75%, or at least 100%, or at least 150%, or at least 200%, or at least 300%, or at least 500%, or at least 750%, relative to a 100% Cellulose Comparative composition.
  • a Williams Slowness test is a measure providing one with an indication of the drainage rate of a aqueous composition. Lower numbers mean a faster draining composition.
  • the Composition and Compositions used to make wet laid products, including the co-refined Composition can have a Williams Slowness of less than 200, or less than 190, or less than 180, or less than 170, or less than 160, or less than 150, or less than 140, or less than 130 seconds, or less than 100 seconds, or less than 80 seconds, or not more than 70 seconds, or not more than 65 seconds, or not more than 60 seconds, or not more than 50 seconds, or nor more than 40 seconds, or not more than 30 seconds, or not more than 25 seconds, or not more than 20 seconds, or not more than 15 seconds.
  • the Composition is refined sufficiently to provide a Composition having a Williams Slowness of at least 5 seconds, or at least 8 seconds, or at least 10 seconds, or at least 15 seconds, or at least 20 seconds, or at least 25 seconds, or at least 40 seconds, or at least 60 seconds, or at least 70 seconds, or at least 80 seconds, or at least 100 seconds, or at least 120 seconds, or at least 140 seconds.
  • a Canadian Standard Freeness test is also a measure providing one with an indication of the drainage rate of a composition. Higher numbers mean a faster draining composition.
  • the Composition and compositions used to make wet laid products, including co-refined Compositions can have a Canadian Standard Freeness of at least 200, or at least 250, or at least 260, or at least 270, or at least 280, or at least 290, or at least 300, or at least 310, or at least 320, or at least 330, or at least 340, or at least 350, or at least 360 ml.
  • the Composition Before refining, can have a CSF of more than 700, or at least 750, or at least 800.
  • the CSF of the Composition is desirably at most 700, or at most 600, or at most 550, or at most 500, or at most 475, or at most 450, or at most 425, or at most 400, or at most 375, or at most 350, or at most 325, or at most 300, or at most 280.
  • the Compositions and the products containing or obtained with the Compositions have a lower Gurley Porosity than the 100% Cellulose Comparative
  • Examples of Gurley Porosities obtainable with the Composition are less than 75, or less than 70, or less than 65, or less than 60, or less than
  • the wet laid products containing or obtained by the Composition have improved water permeability.
  • Increased water permeability can have a number of advantages, including improved water drainage, improved evaporation rate from the interior of the web, reduced pressure drop across filter media, faster drying time, faster web machine line speeds, lower residence time of contaminants contacting the fibers which is useful in a de cking cell, and increased amount and rate of liquid and moisture absorption which is useful in a variety of applications such as tea bags and single serve beverage pods/containers.
  • Water permeability is measured by the Water
  • Composition is at least 1.7, or at least 1.8, or at least 1.9, or at least 2.0 or at least 2.3 or at least 2.5, or at least 3.0 or at least 5 ml/min/cm2/bar and at basis weights of at least 20g/m2, or at least 25 g/m2, or at least 30 g/m2, or at least 35 g/m2, or at least 40 g/m2, or at least 45 g/m2, or at least 50 g/m2, or even at basis weights of at least 60 g/m2, or even at basis weights of at least 70 g/m2, or at least 75 g/m2, or at least 80 g/m2, or at least 85 g/m2, or at least 90 g/m2, or at least 95 g/m2. [0440] In one or any of the embodiments mentioned, the water
  • Composition including co-refined Compositions is increased by at least 5%, or at least 8%, or at least 10%, or at least 12%, or at least 15%, or at least 20%, or at least 25%, or at least 50%, or at least 75%, or at least 100%, or at least 150%, or at least 200%, or at least 300%, or at least 400%, relative to a 100% Cellulose Comparative composition.
  • the wet laid products containing or obtained by the Composition can have smaller mean flow pore size with increased water permeability.
  • a smaller pore size can be achieved by the same methods mentioned above.
  • This feature provides one with the ability to improve on a large variety of end use applications where water permeability combined with size exclusion is desired.
  • Such applications include, for example, liquid filtration such as beer, juices, wine and milk filters to obtain the benefit of maintaining over a longer life span or reducing applied pressure at acceptable flow rates while continuing or improving exclusion of small particles, and desalination pre-filtration.
  • the wet laid web product has a water permeability of at least 1.7, or at least 1.8, or at least 1.9, or at least 2.0 or at least 2.3 or at least 2.5, or at least 3.0 or at least 5 ml/min/cm2 and a mean flow pore size of less than 20 microns, or less than 15 microns, or less than 10 microns on a web having a density within a range of 0.342 to 0.602 g/cm3.
  • a water filter having an increased water flow at a constant pressure drop relative to a 100% Cellulose Comparative composition at the same basis weight.
  • the water filter can have an increase water flow of at least 25%, or at least 50%, or at least 75%, or at least 100%, or at least 150%, or at least 200%, or at least 300%, or at least 500%, or at least 750%.
  • the increased water flow can occur on water filters having a mean flow pore size of less than the 100% Cellulose Comparative composition.
  • the web (which is any wet laid product or sheet) can have a dry tensile strength of at least 100, or at least 500, or at least 1000, or at least 2000, or at least 2500, or at least 2750, or at least 3000, or at least 4000, or more than 4900, or at least 5000, or at least 6000, or at least 7000, or at least 8000 gram force as measured on a 15 mm wide strip measured according to TAPPI T 494 from handsheets made by either method described below. Unless stated otherwise, any reference to dry tensile strength throughout this description is measured by this method.
  • the web can have a dry tensile strength of up to 15,000, or up to 13,000, or up to 12,000, or up to 1 1 ,000, or up to 10,000, or up to 9,000-gram force measured as noted above.
  • the webs e.g. wet laid products including sheets
  • the webs can have a dry tensile strength of at least 163 gram force/mm, or at least 6.6 gram force/mm, or at least 33.3 gram
  • the wet laid products are level along the machine and cross direction of the paper. In one embodiment or in any of the mentioned embodiments, the wet laid products are not creped (non-creped). In addition, it is possible to obtain a wet laid product having good tensile strength or any of the other properties described on wet laid products that are non-creped or not creped.
  • the dry tensile strength of the webs made with the co-refined Composition can be improved relative to the same webs containing or obtained by a Post-Addition Composition.
  • the improvement can be at least
  • the loss in dry tensile strength using co-refined Compositions containing short fiber lengths is less than that observed with longer fiber lengths, e.g. 6 mm.
  • wet laid products containing or obtained by Compositions having low amounts of CE staple fibers and which are highly refined can not only maintain the same dry tensile strength of a 100% Cellulose Comparative composition, but can also exceed its strength.
  • Conventional experience is that, in general, the dry tensile strength of a wet laid product will decrease with the addition of synthetic fibers, and the loss of tensile strength is greater or less depending on the type of fiber added.
  • a wet laid product containing cellulose and a CE staple fiber or made thereby having a dry tensile strength that is the same as or greater than a 100% Cellulose Comparative composition.
  • the increase can be at least 2%, or at least 4%, or at least 5%, or at least 7%.
  • CE staple fiber or made thereby having a dry tensile strength that is greater than a 100% Cellulose Comparative composition by at least 2%, or at least 4%, or at least 5%, or at least 7%, or at least 10%, or at least 12%, or at least 15%, or at least 18%, or at least 20%, or at least 23%, or at least 25%, or at least 28%, or at least 30%, or at least 32%, or at least 35%, in which the wet laid product contains at least 5 wt.%, or at least 8 wt.%, or at least 10 wt.%, or at least 12 wt.%, or at least 15 wt.% CE staple fiber.
  • a wet laid product containing cellulose and a CE staple fiber or made thereby having a dry tensile strength that is greater than a 100% Cellulose Comparative composition by at least 2%, or at least
  • the wet laid product contains at least 5 wt.%, or at least 8 wt.%, or at least 10 wt.%, or at least 12 wt.%, or at least 15 wt.% CE staple fiber, and which was refined to a Canadian Standard Freeness not below 300, or not below 325, or not below 350, or not below 375, or not below 400.
  • the stiffness of the wet laid products containing or obtained with crimped CE staple fibers can be improved relative to a 100% Cellulose Comparative composition.
  • the improvement in Gurley stiffness can be at least 5%, or at least 10%, or at least 15%, or at least 20%, or at least 30%, or at least 35%, or at least 50%, or at least 60%, or at least 70%, relative to a 100% Cellulose Comparative composition.
  • Gurley stiffness of a wet laid product can be determined by using a Gurley Stiffness tester with either of the following methods:
  • the web can have a Gurley stiffness, in mg force, of at least 150 mg, or at least 160 mg, or at least 170, or at least 180, or at least 190 mg, or at least 200 mg, or at least 210 mg, or at least 220 mg, or at least 230 mg, or at least 190 mg, or at least 190 mg, in each case at a thickness of at least 100 microns, or at least 150 microns.
  • the web can have a Gurley stiffness, in mg force per microns thickness, of at least 1.0, or at least 1.05, or at least 1.08, or at least 1.1 or at least 1.13, or at least 1.15, or at least 1.18, or at least 1.2, or at least 1.23, or at least 1.25, or at least 1.27, or at least 1.3, or at least 1.32, or at least 1.35, or at least 1.37, or at least 1.4 mg force/microns thickness.
  • the wet laid products can have thicknesses suitable for their intended application.
  • the wet laid products can have a thickness of at least 0.04 mm, or at least 0.05 mm, or at least 0.06 mm, or at least 0.07 mm, or at least 0.08 mm, or at least 0.09 mm, or at least 0.1 mm, or at least 0.12 mm, or at least 0.14 mm, or at least 0.20 mm, or at least 0.25 mm, or at least 0.3 mm, or at least 0.5 mm, or at least 0.65, or at least 0.70 mm, or at least 0.8 mm.
  • the wet laid products exhibit a combination of increased dry tensile strength and either:
  • the wet laid products exhibit a combination of increased dry tensile strength and increased Gurley stiffness, relative to a 100% Cellulose composition.
  • the stiffness can improve by at least 100, or at least 200, or at least 300 mg force, or at least 15%, or at least 20%, or at least 25%, or at least 30%, or at least 35%.
  • the dry tensile strength can improve by at least 1500 gF, or at least 2000 gF, or at least 2250 gF, or at least 2500 gF, or at least 2750 gF, or at least 3000 gF, or at least 10%, or at least 12%, or at least 15%, or at least 18%, or at least 20%, or at least 23%, or at least 25%, or at least 28%, or at least 30%, or at least 32%, or at least 35%.
  • the wet laid products exhibit a combination of increased dry tensile strength and increased Mullen burst strength, relative to a 100% Cellulose composition.
  • the Mullen burst strength can improve by at least 5, or at least 8, or at least 10, or at least 12, or at least 15 psi, or at least 15%, or at least 20%, or at least 25%, or at least 30%, or at least 35%.
  • the dry tensile strength can improve by at least 1500 gF, or at least 2000 gF, or at least 2250 gF, or at least 2500 gF, or at least 2750 gF, or at least 3000 gF, or at least 10%, or at least 12%, or at least 15%, or at least 18%, or at least 20%, or at least 23%, or at least 25%, or at least 28%, or at least 30%, or at least 32%, or at least 35%.
  • the wet laid products exhibit a combination of increased dry tensile strength and increased bulk, or thickness, relative to a 100% Cellulose composition.
  • the thickness can improve by at least 5, or at least 10, or at least 15, or at least 20, or at least 25 microns, or by at least 5%, or at least 10%.
  • the dry tensile strength can improve by at least 1500 gF, or at least 2000 gF, or at least 2250 gF, or at least 2500 gF, or at least 2750 gF, or at least 3000 gF, or at least 10%, or at least 12%, or at least 15%, or at least 18%, or at least 20%, or at least 23%, or at least 25%, or at least 28%, or at least 30%, or at least 32%, or at least 35%.
  • the dry tensile strength can be maintained or improvements relative to a 100% Cellulose composition can be at a basis weight of at least 35 gsm, or at least 40 gsm, or at least 50 gsm, or at least 75 gsm, or at least 80 gsm, or at least 100 gsm, or at least 120 gsm, or at least 150 gsm.
  • the combination of dry tensile strength and any one or a combination of the bulk, Mullen burst, or Gurley stiffness can be maintained or improvements relative to a 100%
  • Cellulose composition can be at a basis weight of at least 35 gsm, or at least 40 gsm, or at least 50 gsm, or at least 75 gsm, or at least 80 gsm, or at least
  • compositions made into wet laid Compositions and products may also exhibit improved water absorbance relative to a 100 cellulose Comparative composition.
  • the water absorbance can be determined by the TAPPI T-558
  • Comparative compositions can be at least 3%, or at least 5%, or at least 7%, or at least 10%, or at least 12%, or at least 15%, or at least 18%, or at least 20%.
  • Composition can be high, which has the advantage of good water uptake on a variety of products, including paper towels.
  • the absorbance can be at least 120 g water/m2, or at least 125, or at least 130, or at least 135 g water/m2, according to the Cobb size TAPPi T-558 test method.
  • the wet laid products containing or obtained by the Composition can also have good water drainage
  • the wet laid products containing or obtained by the Composition can have a Cobb size of at least 120, or at least 125, or at least 130, each in g water/m2, and a Williams Slowness of less than 150 seconds, or less than 140 seconds, or less than 130 seconds, or less than 125 seconds.
  • the wet laid products containing or obtained by the Composition can have a Cobb size of at least 120, or at least 125, or at least 130, each in g water/m2, and a Canadian Standard Freeness, of at least 275, or at least 300, or at least 315, each in ml.
  • the water absorbency of the wet laid products containing or obtained by the Composition is improved by at least 5%, or at least 10%, or at least 15%, or at least 20%, or at least 25%, or at least 40%, or at least 50%, or at least 75%, or at least 100%, relative to a 100 cellulose Comparative composition (e.g. by definition at about the same basis weight).
  • Compositions and products may also exhibit improved water absorbency after a first use (re-absorbency or rewet).
  • the water re-uptake is an important consideration in the ability of a consumer to squeeze water from a saturated wet laid product, and re-use the same product to continue absorbing water after a first or multiple uses.
  • the test method for determining the ability of a wet laid product to absorb water after a first use is described in Example 16.
  • the water absorbency of the wet laid products containing or obtained by the Composition after a first use or rewet is improved by at least 1 %, or at least 2%, or at least 5%, or at least 10%, relative to a 100 cellulose Comparative composition after its first use.
  • the wet laid products containing or obtained by the Composition can have a wet thickness response of a least 0.5%, or at least 1 %, or at least 1.5%, or at least 2%, or at least 3%, or at least 5%, or at least 7%, or at least 10%, or at least 12%, relative to their dry thickness.
  • the test method for measuring wet thickness retention is further described in Table 8 below and is summarized as measuring the thickness of the handsheet sample.
  • the wet laid products containing or obtained by the Composition can have a wet thickness response where the thickness increased relative to a 100%
  • the increase can be at least 0.75%, or at least 2%, or at least 5%, or at least 10%, or at least 15%, or at least 20%, or at least 40%, or at least 50%.
  • the burst strength of the wet laid products containing or obtained from the co-refined Compositions can be maintained relative to a 100% Cellulose Comparative composition, and are improved relative to Post-Addition
  • the burst strength can be determined by testing a handsheet using the Mullen Burst TAPPI T403 method reported in psig.
  • a drop in the Burst strength of the wet laid products can be no more than 20%, or no more than 15%, or no more than 10%, or no more than 5% below the Burst strength of the 100% Cellulose Comparative composition and can be the same as or more than the Burst strength of the 100% Cellulose
  • the Mullen Burst strength of the wet laid products containing or obtained from a co-refined Composition can be at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or at least 60% higher than the Post-Addition compositions.
  • the wet laid products can have a Mullen Burst strength of at least 70 psig, or at least 75, or at least 78, or at least 80 psig.
  • the co-refined Compositions can be made into wet laid products having good and/or improved softness.
  • Softness can be measured as Gurley softness on a Gurley machine by measuring the air flow across the surface of a sheet using the APPITA/AS 1301 -420 test method on a Gurley 4190 S-P-S machine with a soft plate, 4 outstanding raised rods, and a 0.34-pound weight reported in seconds/100 ml.
  • Compositions can have a lower density and higher thickness at a given basis weight with a rougher surface, relative to a 100% Cellulose Comparative Composition, contributing to improved softness.
  • the improvement in softness of the products made with the co refined Composition, relative to 100% Cellulose Comparative compositions, can be at least 5%, or at least 8%, or at least 10%, or at least 12%, or at least 15%, or at least 20%, or at least 23%, or at least 25%.
  • the wet laid products containing or obtained by the co-refined Composition can have both a better softness relative to 100% Cellulose Comparative compositions, while maintaining or having an improved dry tensile strength relative to a Post- Addition Composition.
  • the wet laid product containing or obtained by co-refining the Composition and further containing a plasticizer has an improved or better softness and maintains or improves its tensile strength, relative to a 100% Cellulose
  • Comparative Composition and/or relative to a 100% Cellulose Comparative Composition containing the same type and amount of plasticizer The amount of plasticizer added can be 1 -10 wt.%, or 2-9, or 3-8, or 4-7, or 5-7, in each case wt.% based on the dry weight of the wet laid product.
  • the plasticizer may be added at the size press or in the drying zone or prior to the paper reel. Suitable examples of plasticizers are those mentioned above.
  • the wet laid products containing or obtained by the Composition can, in spite of using synthetic fibers, maintain and even improve its internal tear resistance relative to a 100% Cellulose Comparative composition, as measured by TAPPI T414, modified by either method to reduce variability:
  • Method 1 2 sections are cut out from each of 5 sheets to create a stack set 1 and 2, where each section is large enough to perform 3 tears on each section (e.g. 2x4 inches). Three tear tests are performed on set 1 , and the value is divided by 5.
  • Method 2 3 sections are cut out from one sheet to create a set 1 having a stack of 3 sections. One tear test is conducted on set 1. Repeat the procedure for the remaining 4 sheets, and average the values obtained.
  • the loss in internal tear resistance of these wet laid products containing or obtained by co-refined Compositions can be no more than 10%, or no more than 5%, and can be increased by at least 5% or at least 7%, or at least a
  • the improvement is more evident when the wet laid products containing or obtained with the Compositions have been lightly refined.
  • containing or obtained by the Composition can be at least 100, or at least 105, or at least 110-gram force.
  • the wet laid products containing or obtained by the Composition have high Elrepho brightness, particularly when the cellulose fiber portion of the Composition is a
  • the Compositions can have a better brightness than 100% cellulose and recycled deinked paper.
  • the wet laid products containing or obtained with the co-refined Composition can have a brightness that is at least 1 point, or at least 2 points more than a 100% Cellulose
  • the wet laid products containing or obtained by the Composition can have high brightness of at least 80, or at least 85, or at least 89, or at least 90, or at least 91 , without optical brightners present, or at least 98, or at least 100 or at least 1 10 with optical brightners present (e.g. Ti02).
  • the wet laid products containing or obtained by the Composition have high brightness, particularly when the cellulose fiber portion of the Composition is a waste/recycle cellulose fiber.
  • the degree of brightness of a wet laid product composition is at least 1 %, or at least 1.5%, or at least 2%, or at least 3%, or at least 5%, or at least 7% higher than the 100% Cellulose Comparative composition.
  • the degree of brightness of a wet laid product composition containing or obtained by the Composition in which at least 20 wt.%, or at least 50 wt.%, or at least 75 wt.%, or 100 wt.% of the cellulose fibers in the Composition are waste/recycle cellulose fibers is at least 2%, or at least 3%, or at least 5%, or at least 7%, or at least 10%, or at least 15%, or at least 20% higher than a 100% Cellulose Comparative composition made of the same amount and type of
  • the wet laid products containing or obtained by the Composition have resistance to brightness reversion.
  • Brightness reversion is the loss of brightness of a wet laid product as it yellows during storage over time, particularly in ultraviolet light.
  • the brightness reverted with reference to the initial brightness can be less than 5%, or not more than 4%, or not more than 3%, or not more than 2.5%, or not more than 2.2%, or not more than 2%, or not more than 1.8%, or not more than 1.6%, or not more than 1.5%, or not more than 1.4%, or not more than 1.3%, or not more than 1.2% or not more than 1.1 %, or not more than 1%, or not more than 0.9%, or not more than 0.8%, or not more than 0,7%, or not more than 0.8%, or not more than 0.5%, over any one of 3, 5, or 10 days.
  • wet laid products there are a wide variety of wet laid products that can be made from or contain the Composition.
  • the single layer of the wet laid products, or each layer of a multi-layered wet laid products is obtained without deposition of an aqueous composition containing fibers onto a web.
  • all fibers that are used to form a web are deposited onto the wire with no additional deposition of fibers onto the web formed on the wire.
  • the fiber distribution of cellulose fibers and CE staple fibers relative to each other throughout a cross-section of any one layer of the wet laid product is substantially or completely homogeneous and/or random. Desirably, one cannot identify a high concentration of either CE staple fibers or cellulose fibers relative to each other throughout the thickness of the wet laid web or product.
  • the variety of products that can be made using the Composition in a wet laid process include paper products such as office paper, newsprint and magazine, printing and writing paper, sanitary, tissue/toweling,
  • packaging/container board specialty papers, apparel, bleached board, corrugated medium, wet laid molded products, unbleached Kraft, decorative laminates, security paper and currency, grand scale graphics, specialty products, and food and drink products.
  • Newsprint is mainly used for printing newspapers, flyers, and advertisements and is produced in large quantities. It is made largely from mechanical pulp and/or recovered paper, sometimes including a small amount of filler. The thickness of the paper can vary according to the usage: weights typically range from 40 to 52g/m 2 but can be as much as 65g/m 2 . Newsprint is machine-finished or slightly calendered, white or slightly colored, and is used in reels for printing.
  • Magazine paper is coated or uncoated bleached Kraft paper, suitable for printing or other graphic purposes that can be high gloss bleached coated paper.
  • Printing and writing paper can be coated or uncoated, suitable for printing or other graphic purposes, optionally at least 90% of the fiber used comes from chemical pulp.
  • Uncoated wood free paper can be made from a variety of different fiber blends, with variable levels of mineral filler and a range of finishing processes such as sizing, calendering, machine-glazing and watermarking. This grade includes as business forms, copier, computer, ink- jet paper, stationery and book papers, and greeting cards.
  • Coated printing paper is also suitable for printing or other graphic purposes and coated on one or both sides with minerals such as clay or calcium carbonate. Coating may be done by a variety of methods, both on-machine and off-machine, and may be supplemented by super-calendering.
  • Tissue and toweling covers a wide range of tissue and toweling products for use in households or on commercial and industrial premises. Examples are toilet paper, facial tissues, kitchen towels, hand towels, sports wipes, and industrial wipes.
  • sanitary wet laid products containing or obtained by the Composition include feminine hygiene, adult incontinence, sanitary cleaning wipes, and wound care.
  • the parent stock is made from virgin pulp or waste/recycle fibers or mixtures of these.
  • Packaging wet laid material includes case materials, folding boxboard, paper bags, and wrappings.
  • Case materials include paper board that can mainly be used in the manufacture of corrugated board. They are made from any combination of virgin and waste/recycle fiber and can be bleached, unbleached or mottled. Included are Kraftliner, testliner, semi chemical fluting, and waste-based fluting.
  • Folding box board is often referred to as carton board, it may be single or multiple layers, coated or uncoated. It is made from virgin and/or recovered fiber and has good folding properties, stiffness and scoring ability.
  • Wrappings up to 150 g/m2, is paper whose main use is wrapping or packaging made from any combination of virgin or recovered fiber and can be bleached or unbleached. They may be subject to various finishing and/or marking processes. Included are sack Kraft, other wrapping Krafts, sulphite and grease proof papers. Wrappings include wraps for straws, twisting applications such as for wrapping candy and chewing gum, gift wrap, and wrapping for mailed products.
  • Specialty papers is a category that includes other paper and board for industrial and special purposes, including cigarette wrapping papers (tipping, tobacco wrap, or plug wrap), air and liquid filters, as well as gypsum liners (or dry wall); special papers for waxing, insulating, roofing, asphalting; and other specific applications or treatments such as label products (for cans, jars, bottles, consumer printable labels, office labels), metallized paper, photographs, disposable bed sheeting and linens, acoustics, wallboard tape paper, playing cards, medical packaging paper, envelopes, blotter paper, sticky notes, medical tape, pipe jacket outside liner, tea bag envelope, gaskets, and sublimation papers for digital transfer printing onto such products such as shirts, textiles, promotional goods, skis and snowboards, curtains, bed linens, advertising banners, coffee filters, overlay papers as protective layers in flooring, kitchen countertops, and decorative wallcovering; battery separators; sausage wrapping paper; table cloths, disposable bed sheets and head rest sheets, vacuum cleaner bag paper, geotextiles,
  • the Compositions are also useful in a variety of other specialty paper applications.
  • One such application is for use in greaseproof paper and glassine products.
  • Greaseproof paper is subjected to high refining energy and/or intensity to cause the cellulose fibers to highly fibrillate, and the wet laid products made from these highly co-refined Compositions can then be calendered to increase their density and reduce pore size.
  • Such wet laid products can be treated with sizing agents to make them fat or oil repellant.
  • Such wet laid products are useful as wrappings for snacks, cookies, candy and other oily foods.
  • the wet laid glassine products can be treated with sizing agents that also make them smooth and glossy. Such glassine products are good for use as liners for fast foods and baked goods.
  • the Compositions can also be highly co-refined to make parchment paper utilizing acid treated cellulose pulp. [0500] The Compositions are also useful in a variety of paperboard applications.
  • they wet laid products containing or obtained by the Compositions can be white board as inner liners to cardboard containers that can optionally be coated with wax or laminated with polyethylene; solid board particularly useful to make milk and juice containers as well as cups for fountain drinks; chipboard containing waste/recycle content as outer carton layers of containers such as for cereal boxes and tea cartons; and fiberboard having an outer Kraft layer and an inner white board layer to provide good impact and compression resistance, which when laminated with a polymer or metal, can provide good barrier properties to protect against moisture intrusion for such items and coffee and milk powders, and a variety of other bulk food and retail food products.
  • Bleached board products include gift wrap boxes, food packaging, electronics packaging.
  • Decorative laminate products include printed or embossed paper laminated to a rigid substrate, including as paper in saturated Kraft, or in the core sheet.
  • Decorative laminates can be used as countertops, decorative wall coverings, and screens.
  • Security paper and currency products include checks, stock certificates, secure documents and printing paper, prescription pads, stamps, tamper evident seals, and currency.
  • Wide format graphics products include large poster boards, wall poster, wallcover bases, airport graphics, billboard graphics, signage, and vehicle graphics.
  • Disposable food and drink products include coated and uncoated paper products as lids, sealing paper, trays, cups, food casing papers (e.g. sausage casings), machine glaze base paper used in lidding or sealing, and any other food or drink containers and sealing/lidding.
  • these products are biodegradable and/or compostable.
  • bale is not added to the bale, and the bale optionally does not contain cellulose fibers.
  • the bale is
  • CE staple fibers withdrawn from a compressed bale to a hydropulper improve the tensile strength and/or burst strength of the resulting wet laid products relative to wet laid products containing the same CE staple fibers in the same amount under the same process conditions that were withdrawn as a loose or non-compressed mass from a box.
  • a process for making a wet laid product by withdrawing CE staple fiber from a compressed bale of CE staple fibers and feeding them to a hydropulper.
  • a wet laid facility is fed with cellulose ester (CE) staple fibers by feeding to a hydropulper, or a blend tank directly or indirectly in fluid communication with a hydropulper, CE staple fibers withdrawn from a bale or roll comprising more than 90 wt.% randomly oriented and compressed cellulose ester (CE) staple fibers based on the weight of all contents in the bale or roll, wherein the CE staple fibers have:
  • DPF denier per filament
  • the bale can be shipped to a waste/recycle mill or to a paper mill or a tissue mill.
  • the CE staple fibers can be compressed under a load, and compressed CE staple fibers are wrapped while under load, desirably in an airtight wrapper and sealed. Vacuum can be applied to the wrapped bale to withdraw air prior to or after sealing.
  • the CE staple fibers are introduced into a bale chute containing at least a portion of the wrapping, pressed under the load of platen driven by a ram, and while under the load, wrapped or packaged at least in part.
  • furnish and handsheets are prepared according to Method 1 by one lab (Lab 1 ) and furnish and handsheets are also prepared according to Method 2 by an external second lab (Lab 2).
  • the preparation of handsheets by Method 1 use the furnish of Method 1
  • the preparation of handsheets by Method 2 use the furnish of Method 2.
  • NBSK Northern Bleached Softwood Kraft pulp
  • the appropriate mass of NBSK pulp 180 g for 100% pulp samples, 172.8 g cellulose fiber for 4% CE staple fiber samples, and cellulose fiber 151.2 g for 16% CE staple fiber samples
  • the zero-load is set. Zero-load is set by filling the Valley Beater with deionized water and turning on the motor to circulate the water. Weight is added to the bedplate load arm and a sliding weight is adjusted until the bedplate made audible contact with the rotor bars.
  • the Valley Beater After setting the zero-load, the Valley Beater is emptied and the 10L sample is poured into the Valley Beater. If the sample requires CE staple fiber for co- refining, the CE staple fiber is added at this point (7.2 g for the 4% samples and 28.8 g for the 16% samples). An additional 1.5L of deionized water is added to bring the consistency to 1.56%. All weight is removed from the load arm and the mixture is circulated for 5 minutes with no-load to accomplish uniform mixing and dispersion of the fibers. The motor is stopped, and a sample is taken (to) for freeness testing then the zero-load weight is added to the load arm of the Valley Beater. In addition to the zero-load weight, an additional 5-pound weight is added for refining load.
  • the motor is turned on and the mixture is refined for 5 minutes.
  • the motor is stopped and another sample (ts) is taken for freeness testing.
  • the motor is turned on and the mixture is refined for 5 minutes.
  • the motor is stopped and another sample (tio) is taken for freeness testing.
  • the motor is turned on and the mixture is refined for 5 minutes.
  • the motor is stopped and another sample (tis) is taken for freeness testing.
  • An additional 6.5 liters of deionized water is added to the Voith Valley Beater to further dilute the sample. All weight is removed from the load arm and the mixture is circulated for 1 minute in the Valley Beater.
  • each batch of slurry is drained into 5-gallon buckets and are ready to use for handsheets at 1.0% consistency.
  • a volume of slurry expected to equal the OD dry target Grams Per Square Meter (GSM) is withdrawn.
  • the volume of the slurry used ranged between 650 ml and 850 ml depending on the specific blend of pulp prepared.
  • a consistency sheet is produced for each set of sheets to be produced. Each consistency sheet began with a charge of 7.432 grams dry equivalent fiber, or 743 ml of pulp slurry diluted to 1 % consistency. Adjustments are calculated from this baseline to bring sheets into the target GSM range for each batch of slurry processed into hand sheets.
  • the purpose of the consistency sheet is to calculate the exact volume needed to produce sheets that repeatedly weigh within the required GSM specifications of +/- 5% of the 80gsm target basis weight.
  • the volume of pulp slurry withdrawn is added to a blending apparatus, in this case, a TAPPI messemer disintegrator.
  • the slurry added to the blender is diluted further aid in dispersion of the fibers prior to adding the slurry to the sheet-forming machine. For instance, if 500 ml of slurry is required to form a 60 GSM hand sheet, and the blender has capacity of 1.5 L, then 800-1000 ml of additional water is added to dilute the slurry and aid in dispersion during mixing. The slurry is disintegrated (mixed at a low sheer) for 60 seconds.
  • the slurry is disintegrated (mixed at a low sheer) for 60 seconds.
  • disintegrated slurry is then added to the head box of an AMC 12-inch X 12- inch hand sheet-forming machine, which is prefilled with 26 liters of city water. This gives a consistency of ⁇ 0.05% in the handsheet mold.
  • the height of the fill line for the particular machine used is 1 1 inches.
  • the diluted slurry is plunged 6 times within approximately 15 seconds and after the final plunge is pulled up and over the closest corner of the head box in order to prevent excessive dripping back into the head box which could potentially disturb the water column and result in undesired patterns forming on the surface of the sheet when“dropped.”
  • the hand sheet is then“dropped” by releasing the drain knife-valve such that the water level drops smoothly and evenly within
  • the head box of the hand sheet forming machine is opened and the forming wire with the wet sheet is transferred to a vacuum device (slotted pipe connected to a vacuum source.
  • the wire and wet sheet are pulled across the vacuum slot to draw additional water out of the sheet through the wire.
  • the vacuum-couched sheet is then covered with a single sheet of blotter paper on the non-wire side, and separated from the forming wire by flipping the wire side up and removing the forming wire.
  • a second sheet of blotter paper is placed on the now exposed wire side of the sheet. This blotter-sample-blotter“sandwich” is placed to the side so that 3 additional sample“sandwiches” can be stacked together for pressing.
  • an additional sheet of blotter paper is added to the top and to the bottom of the stack and the stack is transferred a 14” x 14” Voith Sheet Press and

Abstract

La présente invention concerne une balle de feuilles constituées de fibres de cellulose vierges et/ou de déchets/recyclage et de fibres discontinues d'ester de cellulose (CE) qui peut être introduite dans un triturateur. Les fibres discontinues de CE présentent : i. un denier par filament (DPF) inférieur à 3, ou ii. une longueur de coupe inférieure à 6 mm, ou iii. un gaufrage, ou iv. une combinaison quelconque de deux ou plus parmi (i) à (iii). Les balles peuvent être alimentées et introduites sous forme de balles entières dans un triturateur, ou un réservoir de mélange directement ou indirectement en communication fluidique avec un triturateur, au moyen du même système d'alimentation utilisé pour alimenter en cellulose le triturateur et éviter de devoir défibrer par traction ou étirage des fibres depuis un récipient de type boîte dans un triturateur.
PCT/US2019/047170 2018-08-23 2019-08-20 Balle de recyclage comprenant un ester de cellulose WO2020041248A1 (fr)

Applications Claiming Priority (10)

Application Number Priority Date Filing Date Title
US201862721806P 2018-08-23 2018-08-23
US201862721823P 2018-08-23 2018-08-23
US201862721817P 2018-08-23 2018-08-23
US62/721,817 2018-08-23
US62/721,806 2018-08-23
US62/721,823 2018-08-23
US16/522,956 2019-07-26
US16/522,961 US11286619B2 (en) 2018-08-23 2019-07-26 Bale of virgin cellulose and cellulose ester
US16/522,956 US11230811B2 (en) 2018-08-23 2019-07-26 Recycle bale comprising cellulose ester
US16/522,961 2019-07-26

Publications (1)

Publication Number Publication Date
WO2020041248A1 true WO2020041248A1 (fr) 2020-02-27

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040258910A1 (en) * 2003-06-19 2004-12-23 Haile William Alston Water-dispersible and multicomponent fibers from sulfopolyesters
WO2007078537A1 (fr) * 2005-12-15 2007-07-12 Dow Global Technologies Inc. Articles ameliores en cellulose contenant une composition d’additif
WO2008144304A1 (fr) * 2007-05-16 2008-11-27 Buckman Laboratories International, Inc. Procédés pour contrôler des contaminants organiques présents dans des fibres
US9175440B2 (en) * 2012-01-31 2015-11-03 Eastman Chemical Company Processes to produce short-cut microfibers
US9617685B2 (en) * 2013-04-19 2017-04-11 Eastman Chemical Company Process for making paper and nonwoven articles comprising synthetic microfiber binders

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040258910A1 (en) * 2003-06-19 2004-12-23 Haile William Alston Water-dispersible and multicomponent fibers from sulfopolyesters
WO2007078537A1 (fr) * 2005-12-15 2007-07-12 Dow Global Technologies Inc. Articles ameliores en cellulose contenant une composition d’additif
WO2008144304A1 (fr) * 2007-05-16 2008-11-27 Buckman Laboratories International, Inc. Procédés pour contrôler des contaminants organiques présents dans des fibres
US9175440B2 (en) * 2012-01-31 2015-11-03 Eastman Chemical Company Processes to produce short-cut microfibers
US9617685B2 (en) * 2013-04-19 2017-04-11 Eastman Chemical Company Process for making paper and nonwoven articles comprising synthetic microfiber binders

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