WO2023119046A1 - Fluff pulp - Google Patents
Fluff pulp Download PDFInfo
- Publication number
- WO2023119046A1 WO2023119046A1 PCT/IB2022/061988 IB2022061988W WO2023119046A1 WO 2023119046 A1 WO2023119046 A1 WO 2023119046A1 IB 2022061988 W IB2022061988 W IB 2022061988W WO 2023119046 A1 WO2023119046 A1 WO 2023119046A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- pulp
- fluff pulp
- fluff
- range
- fibers
- Prior art date
Links
- 238000000034 method Methods 0.000 claims abstract description 10
- 230000008569 process Effects 0.000 claims abstract description 5
- 239000000835 fiber Substances 0.000 claims description 26
- 238000010521 absorption reaction Methods 0.000 claims description 11
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 9
- 229910021653 sulphate ion Inorganic materials 0.000 claims description 9
- 239000011122 softwood Substances 0.000 claims description 8
- 238000005194 fractionation Methods 0.000 claims description 6
- 241000218657 Picea Species 0.000 claims description 5
- 235000008124 Picea excelsa Nutrition 0.000 claims description 5
- 235000008582 Pinus sylvestris Nutrition 0.000 claims description 4
- 241000218626 Pinus sylvestris Species 0.000 claims description 4
- 238000001035 drying Methods 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 239000007788 liquid Substances 0.000 abstract description 6
- 238000003892 spreading Methods 0.000 abstract description 5
- 230000007480 spreading Effects 0.000 abstract description 5
- 229920000247 superabsorbent polymer Polymers 0.000 description 5
- 230000002745 absorbent Effects 0.000 description 4
- 239000002250 absorbent Substances 0.000 description 4
- 229920001577 copolymer Polymers 0.000 description 4
- 238000004537 pulping Methods 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- 206010021639 Incontinence Diseases 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- 229920000297 Rayon Polymers 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 235000013305 food Nutrition 0.000 description 2
- 239000011121 hardwood Substances 0.000 description 2
- 239000004816 latex Substances 0.000 description 2
- 229920000126 latex Polymers 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 235000004710 Abies lasiocarpa Nutrition 0.000 description 1
- 244000166033 Abies lasiocarpa Species 0.000 description 1
- 229920002126 Acrylic acid copolymer Polymers 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229920000742 Cotton Polymers 0.000 description 1
- 229920002785 Croscarmellose sodium Polymers 0.000 description 1
- 235000014466 Douglas bleu Nutrition 0.000 description 1
- 229920000433 Lyocell Polymers 0.000 description 1
- 240000000020 Picea glauca Species 0.000 description 1
- 235000008127 Picea glauca Nutrition 0.000 description 1
- 235000008331 Pinus X rigitaeda Nutrition 0.000 description 1
- 235000011613 Pinus brutia Nutrition 0.000 description 1
- 241000018646 Pinus brutia Species 0.000 description 1
- 241000218606 Pinus contorta Species 0.000 description 1
- 241001236219 Pinus echinata Species 0.000 description 1
- 235000005018 Pinus echinata Nutrition 0.000 description 1
- 241000142776 Pinus elliottii Species 0.000 description 1
- 235000011334 Pinus elliottii Nutrition 0.000 description 1
- 235000017339 Pinus palustris Nutrition 0.000 description 1
- 241000218621 Pinus radiata Species 0.000 description 1
- 235000008577 Pinus radiata Nutrition 0.000 description 1
- 241000218679 Pinus taeda Species 0.000 description 1
- 235000008566 Pinus taeda Nutrition 0.000 description 1
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- 240000001416 Pseudotsuga menziesii Species 0.000 description 1
- 235000005386 Pseudotsuga menziesii var menziesii Nutrition 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- 229920006322 acrylamide copolymer Polymers 0.000 description 1
- 238000004061 bleaching Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229920003020 cross-linked polyethylene Polymers 0.000 description 1
- 239000004703 cross-linked polyethylene Substances 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- 230000029087 digestion Effects 0.000 description 1
- 238000004049 embossing Methods 0.000 description 1
- 239000000194 fatty acid Substances 0.000 description 1
- 229930195729 fatty acid Natural products 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000002655 kraft paper Substances 0.000 description 1
- 235000014684 lodgepole pine Nutrition 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 239000005022 packaging material Substances 0.000 description 1
- 229920001495 poly(sodium acrylate) polymer Polymers 0.000 description 1
- 229920002401 polyacrylamide Polymers 0.000 description 1
- 229920000058 polyacrylate Polymers 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 229920002239 polyacrylonitrile Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000002964 rayon Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 235000000673 shore pine Nutrition 0.000 description 1
- NNMHYFLPFNGQFZ-UHFFFAOYSA-M sodium polyacrylate Chemical compound [Na+].[O-]C(=O)C=C NNMHYFLPFNGQFZ-UHFFFAOYSA-M 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 239000010421 standard material Substances 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000004583 superabsorbent polymers (SAPs) Substances 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
- 230000000930 thermomechanical effect Effects 0.000 description 1
- 239000000080 wetting agent Substances 0.000 description 1
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
- D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
- D21H11/02—Chemical or chemomechanical or chemothermomechanical pulp
- D21H11/04—Kraft or sulfate pulp
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F13/00—Bandages or dressings; Absorbent pads
- A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
- A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
-
- 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
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/001—Modification of pulp properties
-
- 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
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/001—Modification of pulp properties
- D21C9/007—Modification of pulp properties by mechanical or physical means
-
- 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
-
- 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
- D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
- D21H27/002—Tissue paper; Absorbent paper
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F13/00—Bandages or dressings; Absorbent pads
- A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
- A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
- A61F2013/530007—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium being made from pulp
- A61F2013/530021—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium being made from pulp being made in soft wood pulp
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F13/00—Bandages or dressings; Absorbent pads
- A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
- A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
- A61F2013/530481—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium having superabsorbent materials, i.e. highly absorbent polymer gel materials
Definitions
- the present invention is directed to a fluff pulp having improved compressibility and improved liquid spreading.
- the invention is also directed to a process for producing such fluff pulp and to the use thereof.
- Fluff pulp is commonly made from softwood pulp from sulphate pulping. Depending on the pulping method, the properties of fluff pulp differs.
- Raw materials for softwood pulp may be various softwood species, such as Scots pine, Norway spruce, Southern pine, Loblolly pine, Slash pine, Radiata pine, Douglas fir, Hemlock Cedar, White spruce, Lodgepole pine, Alpine fir or mixtures thereof.
- Fluff pulp is used for example for producing absorption cores for hygiene products and in airlaid-nonwoven for various applications such as pre-formed absorbent cores, wipes, tabletop, food pads etc.
- the present inventors have surprisingly found that by using a specific fraction of a fiber population, it is possible to obtain a fluff pulp that is easier to densify compared to commonly used fluff pulp made from the whole fiber population. A more densified structure with smaller pores also increases the wicking/spreading length and liquid spreading capacity of products comprising the fluff pulp according to the present invention.
- a standard fluff pulp is fractionated, so that the average fibre length in one of the fractions decreases from about 2 mm to about 1.4 mm, and the coarseness decreases from about 178 to about 159 pg/m. It was found that this fraction has increased compressibility.
- the present invention is thus directed to fluff pulp having length weighted average fiber length in the range of from 1 .3 to 1 .5 mm and coarseness in the range of from 152 to 166 pg/m and having absorption time, in the dry defibrated state, in the range of from 2 to 4 seconds according to the standard SCAN-C 33:80 and having compressibility, measured at 70 kPa, in the range of from 0.065 to 0.080 g/cm 3 .
- the present invention is also directed to a method to produce said fluff pulp.
- the present invention is also directed to the use of said fluff pulp.
- the fluff pulp is produced and delivered to customers in the form of rolls.
- the fluff pulp is first defibrated.
- the defibrated pulp is then used in the manufacture of for example absorption cores for hygiene products and in airlaid-nonwoven for various applications such as pre-formed absorbent cores, wipes, tabletop, food pads etc. Description of the figures
- Fig 1 Fiber length distribution of reference pulp and fractionated pulp.
- fluff means defibrated, i.e. fiberized or shredded “fluff pulp”.
- the term “absorption time” refers to the absorption properties of fluff pulp according to the standard SCAN-C 33:80, which involves the determination of the time consumed to completely saturate a standardized test specimen with absorbed liquid.
- a 3g fluff sample, 50 mm in diameter, is formed in a forming unit. The sample is placed in a sample holder and a load of 2.8 kPa is applied. Tap water (23°C) is applied underneath and the time required for the water to reach the top of the sample is recorded (average of 5 replicates).
- the term “compressibility” refers to the density of a defibrated fluff pulp sample, wherein the sample has been prepared at a specified pressure measured after different pressures (70 kPa or 1380 kPa). This is done as follows: 3g fluff sample, 50 mm in diameter, is formed in a forming unit and compressed in a tube with a cross sectional area of 19.625 cm 2 in an Instron with a speed of 600 mm/min. The density of the compressed sample is calculated after measuring the thickness after 2 minutes waiting time and determining the weight of the compressed sample.
- the compressibility, measured at 70 kPa is in the range of from 0.065 to 0.080 g/cm 3 , preferably in the range of from 0.067 to 0.074 g/cm 3 .
- the compressibility, measured at 1380 kPa is in the range of from 0.250 to 0.300 g/cm 3 , preferably in the range of from 0.260 to 0.290 g/cm 3 .
- the fluff pulp according to the present invention can be produced by the steps of a) preparing sulphate pulp; b) subjecting the pulp to fractionation; c) retaining a pulp fraction having length weighted average fiber length in the range of from 1.3 to 1.5 mm; d) drying the pulp to obtain fluff pulp, having a moisture content of less than 10 weight-%, in the form of a roll.
- Fluff pulp fibers may be prepared by one or more known or suitable digestion, refining, and/or bleaching operations such as, for example, known mechanical, thermomechanical, chemical and/or semichemical pulping and/or other well-known pulping processes.
- the pulp is preferably sulphate pulp (Kraft pulp).
- the cellulosic fibers of the fluff pulp according to the present invention preferably originate from softwood such as spruce and/or pine.
- the sulphate pulp originates to at least 90% from softwood, less than 10% hardwood has been used in the preparation of the sulphate pulp.
- the sulphate pulp mainly originates from softwood but may contain traces of hardwood.
- from 65 wt-% to 90 wt-% of the fibers are fibers from Scots pine and from 10 wt-% to 35 wt-% of the fibers are fibers from Norway spruce.
- the pulp used according to the present invention is fractionated.
- the fractionation is carried out on wet pulp in a pressure screen.
- the pressure screen has a hole diameter in the range of from 1.0 mm to 1.4 mm, preferably in the range of from 1.1 mm to 1.3 mm, such as 1.2 mm.
- the fractionation is carried out on wet pulp in one step.
- the inject pulp is pumped through the screen and split into one finer fraction and one coarser fraction.
- the flow rate is typically about 1000 l/min.
- a pulp consistency of 10 g/l thus gives a mass flow of 10 kg/min.
- the mass reject ratio in the screen is selected to give the desired fiber length in the finer fraction (the accept fraction).
- the pulp may be diluted to a desired consistency, such as between 3 and 15 g/l, such as between 3 and 6 g/l, before fractionation.
- the pulp is washed, either before or after fractionation.
- the washing is typically carried out using water and may be carried out in one or more steps and may involve filtration.
- the pH may be adjusted.
- the pH of the washed pulp should in the range of from 5 to 8, such as from 5 to 7.
- the washed pulp preferably contains less than 0.5 weight-% (based on the solids) extractives, more preferably less than 0.2 weight-% extractives, even more preferably less than 0.1 weight-% extractives and most preferably less than 0.05 weight-% extractives.
- extractives are for examples resins and fatty acids.
- the washed pulp is dried on a drying machine using methods known in the art.
- the dry pulp is formed into rolls after drying.
- the dried material has a moisture content of less than 10 weight-% (ISO 287), preferably less than 9%, such as in the range of from 6 to 9 weight-%.
- the fluff pulp or dried web may be fed into one or more mill, such as hammermills, saw mills, knife mills, and/or pin mills, or any combination thereof. They may have a series of saws, knives, or pins, or small hammers, for example, that rotate at high speed separating the pulp into individual loose fibers.
- hammermills such as hammermills, saw mills, knife mills, and/or pin mills, or any combination thereof. They may have a series of saws, knives, or pins, or small hammers, for example, that rotate at high speed separating the pulp into individual loose fibers.
- the fluff (i.e. the defibrated form of the fluff pulp) according to the present invention can be used in articles and products wherein fluff is typically used.
- the fluff can be used in absorption cores in baby diapers, incontinence products and feminine hygiene products.
- the fluff is also the main component in airlaid nonwoven.
- One embodiment of the present invention relates to a core, comprising the fluff and one or more superabsorbent polymer (SAP).
- the fluff may be combined with one or more superabsorbent polymers (SAP).
- SAPs are known in the absorbent product art.
- SAPs include starch-acrylonitrile copolymer, hydrolyzed starchacrylonitrile copolymer, acrylic acid (co)polymer, acrylamide (co)polymer, polyvinyl alcohol, polyacrylate/polyacrylamide copolymers, polyacrylic acid (co)polymers, sodium polyacrylate, ethylene maleic anhydride copolymer, cross-linked carboxymethylcellulose, polyvinyl alcohol copolymer, polyethylene oxide, cross-linked polyethylene oxide, and starch grafted copolymer of polyacrylonitrile, salts thereof, and combinations thereof.
- the amount of SAP in the core may suitably range from 1 to 95% by weight of the core.
- the fluff pulp according to the present invention can, following defibration, for example be used in absorption cores and in airlaid nonwovens. It can be used as or in a liquid absorption material such as in absorbents in diapers, such as baby diapers as well as incontinence products. It can also be used for example in napkins and tissues. Such products can be produced using methods known in the art.
- the products typically comprise one or more further components, such as superabsorbents, polymers, wetting agents, viscose/rayon/lyocell fibers, bicomponent fibre, cotton fiber, other fibers, standard latex binder, specialty latex binder etc.
- a standard fluff pulp of Scots pine and Norway spruce in the proportion 80/20 was fractionated in a pressure screen with hole of diameter 1 .2 mm.
- the average fibre length in one of the fractions decreased from 2.03 to 1 .42 mm, and the coarseness decreased from 178 to 159 pg/m.
- the fibre length distribution curves are seen in Fig 1 .
- the average fiber width decreased from 27.4 to 25.1 pm.
Abstract
The present invention is directed to a fluff pulp having improved compressibility and improved liquid spreading. The invention is also directed to a process for producing such fluff pulp and to the use thereof.
Description
FLUFF PULP
Field of the invention
The present invention is directed to a fluff pulp having improved compressibility and improved liquid spreading. The invention is also directed to a process for producing such fluff pulp and to the use thereof.
Background
Fluff pulp is commonly made from softwood pulp from sulphate pulping. Depending on the pulping method, the properties of fluff pulp differs. Raw materials for softwood pulp may be various softwood species, such as Scots pine, Norway spruce, Southern pine, Loblolly pine, Slash pine, Radiata pine, Douglas fir, Hemlock Cedar, White spruce, Lodgepole pine, Alpine fir or mixtures thereof.
Fluff pulp is used for example for producing absorption cores for hygiene products and in airlaid-nonwoven for various applications such as pre-formed absorbent cores, wipes, tabletop, food pads etc.
Today there is a clear trend towards thinner hygiene products. Thinner products will save packaging materials and transportation space, and this will contribute to a reduction in carbon footprint and logistics costs. Another advantage is more under-wear like products for the end-users for discretion, fit and comfort. Thus, it would be desirable to achieve a more compressible fluff pulp, easier to densify. A more compressible fluff pulp will also improve the liquid spreading properties and have an advantage for air laid nonwoven enabling more distinct embossing pattern which will improve wicking properties.
Summary of the invention
The present inventors have surprisingly found that by using a specific fraction of a fiber population, it is possible to obtain a fluff pulp that is easier to densify compared to commonly used fluff pulp made from the whole fiber population. A more densified structure with smaller pores also increases the wicking/spreading length and liquid spreading capacity of products comprising the fluff pulp according to the present invention.
According to the present invention, a standard fluff pulp is fractionated, so that the average fibre length in one of the fractions decreases from about 2 mm to about 1.4 mm, and the coarseness decreases from about 178 to about 159 pg/m. It was found that this fraction has increased compressibility.
The present invention is thus directed to fluff pulp having length weighted average fiber length in the range of from 1 .3 to 1 .5 mm and coarseness in the range of from 152 to 166 pg/m and having absorption time, in the dry defibrated state, in the range of from 2 to 4 seconds according to the standard SCAN-C 33:80 and having compressibility, measured at 70 kPa, in the range of from 0.065 to 0.080 g/cm3.
The present invention is also directed to a method to produce said fluff pulp.
The present invention is also directed to the use of said fluff pulp. The fluff pulp is produced and delivered to customers in the form of rolls. The fluff pulp is first defibrated. The defibrated pulp is then used in the manufacture of for example absorption cores for hygiene products and in airlaid-nonwoven for various applications such as pre-formed absorbent cores, wipes, tabletop, food pads etc.
Description of the figures
Fig 1 : Fiber length distribution of reference pulp and fractionated pulp.
Detailed description
As used herein, the term, "fluff” means defibrated, i.e. fiberized or shredded “fluff pulp”.
As used herein, the term “absorption time” refers to the absorption properties of fluff pulp according to the standard SCAN-C 33:80, which involves the determination of the time consumed to completely saturate a standardized test specimen with absorbed liquid. A 3g fluff sample, 50 mm in diameter, is formed in a forming unit. The sample is placed in a sample holder and a load of 2.8 kPa is applied. Tap water (23°C) is applied underneath and the time required for the water to reach the top of the sample is recorded (average of 5 replicates).
As used herein, the term “compressibility” refers to the density of a defibrated fluff pulp sample, wherein the sample has been prepared at a specified pressure measured after different pressures (70 kPa or 1380 kPa). This is done as follows: 3g fluff sample, 50 mm in diameter, is formed in a forming unit and compressed in a tube with a cross sectional area of 19.625 cm2 in an Instron with a speed of 600 mm/min. The density of the compressed sample is calculated after measuring the thickness after 2 minutes waiting time and determining the weight of the compressed sample. The compressibility, measured at 70 kPa is in the range of from 0.065 to 0.080 g/cm3, preferably in the range of from 0.067 to 0.074 g/cm3. Preferably, the compressibility, measured at 1380 kPa is in the range of from 0.250 to 0.300 g/cm3, preferably in the range of from 0.260 to 0.290 g/cm3.
The fluff pulp according to the present invention can be produced by the steps of a) preparing sulphate pulp; b) subjecting the pulp to fractionation;
c) retaining a pulp fraction having length weighted average fiber length in the range of from 1.3 to 1.5 mm; d) drying the pulp to obtain fluff pulp, having a moisture content of less than 10 weight-%, in the form of a roll.
Fluff pulp fibers may be prepared by one or more known or suitable digestion, refining, and/or bleaching operations such as, for example, known mechanical, thermomechanical, chemical and/or semichemical pulping and/or other well-known pulping processes. The pulp is preferably sulphate pulp (Kraft pulp). The cellulosic fibers of the fluff pulp according to the present invention preferably originate from softwood such as spruce and/or pine. Preferably, the sulphate pulp originates to at least 90% from softwood, less than 10% hardwood has been used in the preparation of the sulphate pulp. Thus, the sulphate pulp mainly originates from softwood but may contain traces of hardwood. Preferably, from 65 wt-% to 90 wt-% of the fibers are fibers from Scots pine and from 10 wt-% to 35 wt-% of the fibers are fibers from Norway spruce.
The pulp used according to the present invention is fractionated. Preferably, the fractionation is carried out on wet pulp in a pressure screen. Preferably, the pressure screen has a hole diameter in the range of from 1.0 mm to 1.4 mm, preferably in the range of from 1.1 mm to 1.3 mm, such as 1.2 mm. Preferably, the fractionation is carried out on wet pulp in one step. The inject pulp is pumped through the screen and split into one finer fraction and one coarser fraction. The flow rate is typically about 1000 l/min. A pulp consistency of 10 g/l thus gives a mass flow of 10 kg/min. The mass reject ratio in the screen is selected to give the desired fiber length in the finer fraction (the accept fraction).
The pulp may be diluted to a desired consistency, such as between 3 and 15 g/l, such as between 3 and 6 g/l, before fractionation. The pulp is washed, either before or after fractionation. The washing is typically carried out using water and may be carried out in one or more steps and may involve filtration. As part of the washing or immediately after the washing step, the pH may be adjusted. Preferably, the pH of the washed pulp should in the range of from 5 to 8, such as from 5 to 7. The washed pulp preferably contains less than 0.5 weight-% (based on the solids) extractives, more preferably less than 0.2
weight-% extractives, even more preferably less than 0.1 weight-% extractives and most preferably less than 0.05 weight-% extractives. In this context, extractives are for examples resins and fatty acids.
The washed pulp is dried on a drying machine using methods known in the art. The dry pulp is formed into rolls after drying. The dried material has a moisture content of less than 10 weight-% (ISO 287), preferably less than 9%, such as in the range of from 6 to 9 weight-%.
In fiber defibration, the fluff pulp or dried web may be fed into one or more mill, such as hammermills, saw mills, knife mills, and/or pin mills, or any combination thereof. They may have a series of saws, knives, or pins, or small hammers, for example, that rotate at high speed separating the pulp into individual loose fibers.
The fluff (i.e. the defibrated form of the fluff pulp) according to the present invention can be used in articles and products wherein fluff is typically used. Thus, the fluff can be used in absorption cores in baby diapers, incontinence products and feminine hygiene products. The fluff is also the main component in airlaid nonwoven.
One embodiment of the present invention relates to a core, comprising the fluff and one or more superabsorbent polymer (SAP). In the course of making the core, the fluff may be combined with one or more superabsorbent polymers (SAP). SAPs are known in the absorbent product art. Nonlimiting examples of SAPs include starch-acrylonitrile copolymer, hydrolyzed starchacrylonitrile copolymer, acrylic acid (co)polymer, acrylamide (co)polymer, polyvinyl alcohol, polyacrylate/polyacrylamide copolymers, polyacrylic acid (co)polymers, sodium polyacrylate, ethylene maleic anhydride copolymer, cross-linked carboxymethylcellulose, polyvinyl alcohol copolymer, polyethylene oxide, cross-linked polyethylene oxide, and starch grafted copolymer of polyacrylonitrile, salts thereof, and combinations thereof.
The amount of SAP in the core may suitably range from 1 to 95% by weight of the core.
Thus, the fluff pulp according to the present invention can, following defibration, for example be used in absorption cores and in airlaid nonwovens. It can be used as or in a liquid absorption material such as in absorbents in diapers, such as baby diapers as well as incontinence products. It can also be used for example in napkins and tissues. Such products can be produced using methods known in the art. The products typically comprise one or more further components, such as superabsorbents, polymers, wetting agents, viscose/rayon/lyocell fibers, bicomponent fibre, cotton fiber, other fibers, standard latex binder, specialty latex binder etc.
Examples
Example 1
A standard fluff pulp of Scots pine and Norway spruce in the proportion 80/20 was fractionated in a pressure screen with hole of diameter 1 .2 mm.
The average fibre length in one of the fractions decreased from 2.03 to 1 .42 mm, and the coarseness decreased from 178 to 159 pg/m. The fibre length distribution curves are seen in Fig 1 . The average fiber width decreased from 27.4 to 25.1 pm.
The improved properties compared with the standard material are found in the table below.
In view of the above detailed description of the present invention, other modifications and variations will become apparent to those skilled in the art. However, it should be apparent that such other modifications and variations may be affected without departing from the spirit and scope of the invention.
Claims
1. Fluff pulp having length weighted average fiber length in the range of from 1.3 to 1.5 mm and coarseness in the range of from 152 to 166 pg/m and having absorption time, in the dry defibrated state, in the range of from 2 to 4 seconds according to the standard SCAN-C 33:80 and having compressibility, measured at 70 kPa, in the range of from 0.065 to 0.080 g/cm3.
2. Fluff pulp according to claim 1 having coarseness in the range of from 155 to 163 pg/m.
3. Fluff pulp according to claim 1 or 2 having compressibility, measured at 1380 kPa, in the range of from 0.250 to 0.300 g/cm3.
4. Fluff pulp according to any one of claims 1-3 wherein the sulphate pulp is prepared from at least 90% softwood.
5. Fluff pulp according to claim 4, wherein from 65 wt-% to 90 wt-% of the fibers are fibers from Scots pine and wherein from 10 wt-% to 35 wt-% of the fibers are fibers from Norway spruce.
6. Fluff pulp according to any one of claims 1-5, in the form of a roll.
7. A process for preparing fluff pulp comprising the steps of a) preparing sulphate pulp; b) subjecting the pulp to fractionation; c) retaining a pulp fraction having length weighted average fiber length in the range of from 1.3 to 1.5 mm; d) drying the pulp to obtain fluff pulp, having a moisture content of less than 10 weight-%, in the form of a roll.
8. A process according to claim 7 wherein the sulphate pulp is prepared from at least 90% softwood.
9. Fluff pulp obtainable according to the process of claim 7 or 8.
10. A product comprising or prepared from defibrated fluff pulp, wherein said fluff pulp is, prior to defibration, a fluff pulp according to any one of claims 1-6 or claim 9.
11. Airlaid nonwoven comprising or prepared from defibrated fluff wherein said fluff pulp is, prior to defibration, a fluff pulp according to any one of claims 1-6 or claim 9.
12. Absorption core comprising or prepared from defibrated fluff pulp, wherein said fluff pulp is, prior to defibration, a fluff pulp according to any one of claims 1-6 or claim 9.
13. Hygien product comprising absorption core according to claim 12.
9
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE2151591A SE545418C2 (en) | 2021-12-22 | 2021-12-22 | Fluff pulp |
SE2151591-1 | 2021-12-22 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2023119046A1 true WO2023119046A1 (en) | 2023-06-29 |
Family
ID=86901467
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/IB2022/061988 WO2023119046A1 (en) | 2021-12-22 | 2022-12-09 | Fluff pulp |
Country Status (2)
Country | Link |
---|---|
SE (1) | SE545418C2 (en) |
WO (1) | WO2023119046A1 (en) |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1997034047A1 (en) * | 1996-03-13 | 1997-09-18 | The Procter & Gamble Company | Tissue paper containing chemically softened coarse cellulose fibers |
US20130203699A1 (en) * | 2009-05-28 | 2013-08-08 | Gp Cellulose Gmbh | Method for inhibiting the growth of microbes with a modified cellulose fiber |
WO2016134261A1 (en) * | 2015-02-20 | 2016-08-25 | Kimberly-Clark Worldwide, Inc. | Durable and soft wet pressed tissue |
US20160244916A1 (en) * | 2015-02-20 | 2016-08-25 | Weyerhaeuser Nr Company | Low coarseness southern softwood pulps |
US20190276985A1 (en) * | 2018-03-07 | 2019-09-12 | Gpcp Ip Holdings Llc | Low lint paper products and methods of making the same |
WO2020149849A1 (en) * | 2019-01-18 | 2020-07-23 | Kimberly-Clark Worldwide, Inc. | Layered tissue comprising long, high-coarseness wood pulp fibers |
-
2021
- 2021-12-22 SE SE2151591A patent/SE545418C2/en unknown
-
2022
- 2022-12-09 WO PCT/IB2022/061988 patent/WO2023119046A1/en unknown
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1997034047A1 (en) * | 1996-03-13 | 1997-09-18 | The Procter & Gamble Company | Tissue paper containing chemically softened coarse cellulose fibers |
US20130203699A1 (en) * | 2009-05-28 | 2013-08-08 | Gp Cellulose Gmbh | Method for inhibiting the growth of microbes with a modified cellulose fiber |
WO2016134261A1 (en) * | 2015-02-20 | 2016-08-25 | Kimberly-Clark Worldwide, Inc. | Durable and soft wet pressed tissue |
US20160244916A1 (en) * | 2015-02-20 | 2016-08-25 | Weyerhaeuser Nr Company | Low coarseness southern softwood pulps |
US20190276985A1 (en) * | 2018-03-07 | 2019-09-12 | Gpcp Ip Holdings Llc | Low lint paper products and methods of making the same |
WO2020149849A1 (en) * | 2019-01-18 | 2020-07-23 | Kimberly-Clark Worldwide, Inc. | Layered tissue comprising long, high-coarseness wood pulp fibers |
Also Published As
Publication number | Publication date |
---|---|
SE2151591A1 (en) | 2023-06-23 |
SE545418C2 (en) | 2023-09-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4247362A (en) | High yield fiber sheets | |
US5866242A (en) | Soft, strong, absorbent material for use in absorbent articles | |
US6485667B1 (en) | Process for making a soft, strong, absorbent material for use in absorbent articles | |
US11041272B2 (en) | Fluff pulp and high SAP loaded core | |
US6059924A (en) | Fluffed pulp and method of production | |
CA2185537C (en) | Heat treated high lignin content cellulosic fibers | |
WO2000036215A1 (en) | Softened comminution pulp | |
CA2518145A1 (en) | Cross-linked fiber in sheet form and method of making | |
US20030172464A1 (en) | Liquid ammonia explosion treatment of wood fibers | |
US20140041818A1 (en) | Fluff pulp and high sap loaded core | |
US20030234468A1 (en) | Soft, absorbent material for use in absorbent articles and process for making the material | |
WO2001018302A1 (en) | Soft, absorbent material for use in absorbent articles and process for making the same | |
WO2023119046A1 (en) | Fluff pulp | |
WO2023119048A1 (en) | Fluff pulp | |
EP2206523B1 (en) | Treated cellulosic fibers and absorbent articles made from them | |
EP1155192A1 (en) | Softened comminution pulp | |
JP7297966B1 (en) | Pulp sheet for fluff pulp | |
EP4025738A1 (en) | Fluff pulp | |
CA2293513A1 (en) | Liquid ammonia explosion treatment of wood fibers | |
ZA200201480B (en) | Soft, absorbent material for use in absorbent articles and process for making the same. | |
MXPA06004138A (en) | Materials useful in making cellulosic acquisition fibers in sheet form | |
MXPA01006785A (en) | High bulk, high strength fiber material with permanent fiber morphology |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 22910304 Country of ref document: EP Kind code of ref document: A1 |