EP0484398B1 - Chargement de parois cellulaires de fibres de pate toujours humides - Google Patents

Chargement de parois cellulaires de fibres de pate toujours humides Download PDF

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EP0484398B1
EP0484398B1 EP90911505A EP90911505A EP0484398B1 EP 0484398 B1 EP0484398 B1 EP 0484398B1 EP 90911505 A EP90911505 A EP 90911505A EP 90911505 A EP90911505 A EP 90911505A EP 0484398 B1 EP0484398 B1 EP 0484398B1
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never
filled
dried
filler
paper
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German (de)
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EP0484398A1 (fr
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G. Graham Allan
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University of Washington
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University of Washington
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    • 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
    • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
    • D21H17/63—Inorganic compounds
    • D21H17/70—Inorganic compounds forming new compounds in situ, e.g. within the pulp or paper, by chemical reaction with other substances added separately
    • 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
    • D21C9/002—Modification of pulp properties by chemical means; preparation of dewatered pulp, e.g. in sheet or bulk form, containing special additives
    • D21C9/004—Modification of pulp properties by chemical means; preparation of dewatered pulp, e.g. in sheet or bulk form, containing special additives inorganic compounds
    • 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
    • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
    • D21H17/63—Inorganic compounds
    • D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
    • D21H17/675—Oxides, hydroxides or carbonates

Definitions

  • This invention relates to a filled pulp fiber and a filled paper composition wherein the filler is an insoluble precipitate predominantly located within the cell wall of never-dried cellulosic pulp fibers.
  • the location of the filler within the cell walls determines the resulting filled paper composition having increased strength relative to a corresponding conventionally filled paper containing the same amount of the same filler.
  • the present invention also relates to a process for producing a filled pulp fiber and a filled paper composition having increased strength relative to a conventionally filled paper having the same concentration of the same filler material.
  • Papermaking processes often use fillers or opaque pigments to confer some desirable characteristics to the paper product and to provide a cost savings for paper raw materials.
  • Fillers can increase opacity, brightness and printing properties. Fillers are cheaper substitutes than cellulose fibers and can reduce the total cost of the finished paper product. Moreover, fillers can be dried easier than fibers and reduce energy consumption during the papermaking process.
  • paper An essential property of paper for many end uses is its opacity. It is particularly important for printing papers, where it is desirable to have as little as possible of the print on the reverse side of a printed sheet or on a sheet below it be visible through the paper. For printing and other applications, paper must also have a certain degree of brightness, or whiteness. For many paper products, acceptable levels of optical properties can be achieved from the pulp fibers alone. However, in other products, the inherent light-reflective characteristics of the fibers are insufficient to meet consumer demands. In such cases, the papermaker adds a filler.
  • a filler consists of fine particles of an insoluble solid, usually of a mineral origin, suspended in a slurry.
  • the filler particles confer light-reflectance to the paper and thereby increase both opacity and brightness.
  • Adding fillers to paper pulp produces an enhancement of the optical properties of the paper and further produces the advantages of improved smoothness and improved printability. Further, replacing fiber with an inexpensive filler can reduce the cost of the paper.
  • filler addition poses some additional problems.
  • the mechanical strength of the paper is less than could be expected from the ratio of load-bearing fiber to non-load-bearing filler.
  • the mechanical strength of paper can be expressed in terms of burst index, tear index, and tensile index. The usual explanation for this is that some of the filler particles become trapped between fibers, thereby reducing the strength of the fiber-to-fiber hydrogen bonding.
  • the hydrogen bonding is the primary source of paper strength.
  • filler concentrations are often limited to a maximum of about 10% ash content.
  • preflocculated fibers and fillers have been used to increase filler retention and reduce loss of paper strength. Coarser particles of pigment or filler, caused by the preflocculation procedure, are retained more efficiently than the finer particles of pigment. Thus, there is less interference with inter-fiber bonding. This helps improve paper strength. However, paper opacity is reduced with increasing particle size. Moreover, the cost savings associated with the preflocculation technique are insignificant and are offset by additional problems.
  • Craig US-A-2,583,548 (“Craig”), describes a process forming a pigmented cellulosic pulp by precipitating pigment "in and around" the fibers.
  • dry cellulosic fibers are added to a solution of one reactant, for example, calcium chloride, and the suspension is mechanically worked so as to effect a gelatinizing of the dry fibers.
  • a second reactant for example, sodium carbonate, is added so as to effect the precipitation of fine solid particles, such as calcium carbonate.
  • the fibers are then washed to remove the soluble by-product (sodium chloride).
  • the Craig process has considerable limitations.
  • the presence of filler on fiber surfaces and the gelatinizing effect on the fibers are detrimental to paper strength.
  • the gelatinised fibers are so severely broken that both the filler precipitate and the gelled fibers form a slurry.
  • the Craig process has not achieved commercial success despite its disclosure about 39 years ago.
  • the result is an increased retention of filler within the lumen, while removing the hindrance to inter-fiber bonding by removing the filler outside of the fiber lumens.
  • the result is increased paper strength for the amount of filler present.
  • the lumen-loading technique works best with fibers that have been dried.
  • the lumen-loading technique has not proved to be economically or commercially viable.
  • the technique requires the manipulation of large volumes of relatively concentrated filler suspensions agitated at high revolutions for prolonged periods of time.
  • the lumen-loading technique requires a relatively small particle size filler, such as titanium oxide, which is an expensive filler material.
  • the lumen-loading technique will only work for dry softwood fibers having a sufficient number of pit apertures. As the lumens are open at the pits, filler may be lost in the same way that it is introduced. Further, the pores in the cell walls are not filled by the lumen-loading technique.
  • An object of the Present invention is a process for the production of filled pulp fiber composition wherein the starting pulp is a never-dried pulp derived from hardwoods, softwoods, annual plants and combinations thereof, by immersing a never-dried pulp having an internal cell wall pore volume while regaining wet after pulping in a first solution wherein the first solution comprises a soluble salt or salts, filtering the immersed never-dried pulp to remove soluble salt from the exterior of the fiber and the lumen, and then reimmersing the never-dried pulp in a second solution wherein the second solution comprises a soluble salt or salts different from the soluble salt or salts of the first solution, and with the proviso that the interaction of the salt or salts from the first solution and the salt or salts from the second solution form an insoluble precipitate that acts as a filler within the cell wall of the never-dried pulp; and filtering and washing the filled never-dried pulp to form the filled pulp fiber.
  • the starting pulp is a never-dried pulp
  • Another object of the invention is a filled pulp fiber obtainable according to the process of the invention , wherein at least 50% of the filler content is located within the pores of the fiber cell wall.
  • the invention further describes a process for the production of filled paper wherein the starting pulp is a never-dried pulp.
  • the inventive process comprises producing a filled pulp fiber according to the process of the invention and forming paper with the filled pulp.
  • the paper is made by process steps known to those of ordinary skill in the art.
  • the pulp can be used directly for papermaking without drying, or dried as filled pulp fibers and later used for papermaking.
  • the present invention refers to a filled-paper composition
  • a filled-paper composition comprising intact, never-dried cellulose fibers and filler, wherein at least 50% of the filler content is located within the pores or cell wall of the never-dried cellulose fibers.
  • the filled paper composition is characterized by having increased strength compared to a corresponding conventionally filled paper containing the same amount of the same filler.
  • the filler is formed in situ as an insoluble precipitate in an aqueous system.
  • the paper composition may further comprise a coloring agent wherein the coloring agent is a colored precipitate formed in situ that functions as a filler material. Examples of insoluble precipitates that function as filler materials include, for example, calcium carbonate, other precipitates listed in Table 1 herein, and combinations thereof.
  • the paper composition is selected from the group consisting of unbleached kraft paper, bleached kraft paper, sulfite pulp (bleached and unbleached) fine printing paper, fine writing paper, and lightweight newsprint paper.
  • the present invention includes a filled paper product made from filled, never-dried cellulose pulp fibers which are obtainable by the process of the invention, wherein the filled paper is made directly from the filled, never-dried pulp or the filled, never-dried pulp is made, dried, and later used to make paper.
  • the essential steps of the inventive process are as follows:
  • the paper can be made directly with the filled, never-dried pulp fibers by conventional procedures.
  • the filled, never-dried pulp can be dried and later used for papermaking.
  • the filled, never-dried pulp fibers are beaten after filling in the never-dried state or after being once dried. If the unbeaten, filled pulp is dried, the papermaker can control the specifications of the beating process in the papermaking operation.
  • the never-dried cellulose pulp can be derived from hardwoods, softwoods, annual plants such as sugarcane (bagasse), and combinations thereof.
  • the present invention is able to load a precipitate-type filler material within the cell walls or pores located within the cell walls of never-dried pulp fibers by the internal in situ precipitation of insoluble fillers and pigments.
  • None-dried pulp fibers are unique in having relatively large-sized pores located within the interior of the cell wall. These pores collapse when the pulp fiber is dried and are not fully restored by the rewetting of the dried fiber. Therefore, one can optimally precipitate filler material within the cell wall surrounding the lumen only before the fiber is dried.
  • filled fibers, filled by the inventive process and dried cannot be refilled by the inventive process.
  • Filler materials such as pigments and opaque precipitates, are loaded into the pores of the cell walls of never-dried wood pulp fiber by precipitating the filler material inside the pores. This replaces the fluid content of the pore. Excess filler is washed away from the external surface of the fiber and an insignificant amount, if any, of filler material remains within the lumen of the fiber.
  • never-dried pulp fibers are hollow, tubular structures, the fibers develop an extremely large surface area after pulping and retain that large surface area while remaining wet (i.e., never-dried).
  • the large surface area within the never-dried fibers is generously available to soluble salts that are precipitated as papermaking fillers. This preserves the bonding ability of the external cellulosic layers and does not affect the strength of the resulting paper.
  • Figure 1a is a scanning electron micrograph at 2142X magnification showing the surface of filled, never-dried pulp fiber filled according to the inventive process with NiCO3 insoluble precipitate filler.
  • Figure 1b is an electron dispersion analysis (EDAX) of the filled fiber showing Ni location and distribution in the cell wall of the fiber.
  • EDAX electron dispersion analysis
  • Figures 2a, 2b, and 2c are EDAX graphs of Ni (07 box) of a NiCO3-filled, never-dried pulp fiber showing the surface of the fiber, the cell wall of the fiber, and the fiber lumen, respectively. Filler was predominantly present in Figure 2b, indicating the presence of nickel in the cell wall.
  • Figures 3 and 4 illustrate the tensile index and burst index, respectively, of different filler content papers made from never-dried western hemlock pulp (a softwood).
  • the filled circles represent paper made from fibers filled by the inventive process, and the open circles or squares represent paper made from fibers filled by a conventional process, as described in Example 1.
  • the different symbols represent different batches run on different dates.
  • Figures 5, 6 and 7 illustrate tear index, burst index, and tensile index, respectively, for different filler content papers made from red alder pulp (a hardwood).
  • the open circles or squares represent the inventive process with CaCO3 as the filler precipitated in situ , wherein, for the open squares, CaCl2 was the first salt and Na2CO3 was the second salt, and for the open circles, Na2CO3 was the first salt and CaCl2 was the second salt.
  • the closed triangles are data from paper made from mixtures of cell wall filled and unfilled fibers in ratios of 1:3, 1:1, and 3:1, respectively.
  • the open diamonds are red alder, never-dried pulp fibers filled by the conventional techniques described in Example 1.
  • the "x" designation used once-dried red alder pulp, rewetted and filled by the inventive process.
  • Figures 8, 9, and 10 illustrate the tear index, burst index, and tensile index, respectively, for different filler content papers made from spruce CTMP pulp (a softwood).
  • the open squares represent in situ precipitated, never-dried pulp fibers filled by the inventive process.
  • the open circles represent never-dried pulp fibers loaded in a filled paper by a conventional process described in Example 1.
  • Figures 11, 12, and 13 illustrate the tear index, burst index, and tensile index, respectively, for different filler content papers made from bagasse pulps (sugarcane).
  • the filled squares represent in situ precipitated, never-dried pulp fibers filled by the inventive process, with the filled squares being bleached pulp and the open squares being unbleached pulp.
  • the diamonds represent never-dried pulps filled by a conventional process, as described in Example 1, with the filled diamonds being bleached pulp and the open diamonds being unbleached pulp.
  • the triangles represent once-dried, bleached pulp filled by the inventive process. The poor results obtained with the once-dried pulps indicate that pores of the never-dried pulp fibers are necessary to be able to fill the cell walls of fibers.
  • Figure 14 compares the relative decrease in tensile strength as a function of filler content comparing literature data of the lumen-loading technique (triangles or "x" figures) to never-dried pulps filled by the inventive process using red alder hardwood pulp (open squares), bagasse sugarcane pulp (diamonds), and spruce CTMP softwood pulp (closed circles).
  • the pulp obtained is a composite of several hundred concentric lamellae of cellulose microfibils. Each lamella is separated from the others by water-filled spaces (pores) which vary in width from 25 ⁇ 10 ⁇ 10 to about 300 ⁇ 10 ⁇ 10 m (about 25 to about 300 angstroms). The larger spaces are located nearer the periphery, with the narrower spaces located toward the lumen (a central channel of about 10 to about 20 ⁇ m (microns) in width). The spacing of the pores more or less corresponds to the thickness of the lignin in the cellulose wood fiber.
  • the pore size generally has a normal log distribution.
  • a surprising result of the inventive process is that most of the first solution leaves the fiber lumen when the fiber is filtered between the addition of the first and second solutions. This is because the lumen is more open to the external environment than the pores in the cell wall. Thus, little, if any, filler is precipitated in situ in the lumen.
  • the normal log distribution of pore size is a plot of the logarithm of the pore size versus pore frequency.
  • the never-dried pulp fiber has a surface area of about 1,000 m2/g. Upon drying, the surface area reduces to about 1 m2/g. Even though the lamellae swell upon rewetting, the rewetted pulp has a surface area of only about 100 m2/g. Thus, upon drying, most of the pores of the never-dried pulp irreversibly collapse.
  • the inventive composition and processes depend upon the special properties of the never-dried pulp or its equivalents.
  • the never-dried pulp has a large internal surface area of about 1,000 m2/g as a result of the corresponding internal cell wall pore volume of about 1.2 ml/g.
  • the internal cell wall pores are substantially lost by collapse during drying. Anything placed within the pores before drying becomes trapped in the pores, as the pores collapse during drying.
  • the strength of paper made from such in situ precipitation cell wall-filled fibers is greater than the strength of paper made from the usual (conventional) combination of fibers and the same amount of filler particles added to the fibers, when the filler.
  • the conventional mixture of filler and fibers locates the filler between the fibers.
  • the abrasive filler will have less contact with the forming wire on the paper machine. This will result in fewer wire changes being needed for the paper machine in a given period of time.
  • Another advantage of the inventive process and compositions is that larger amounts of filler are used to form paper and maintain the strength of the resulting paper.
  • the paper filler does not require incorporating adhesive polymers to maintain paper strength.
  • paper made using the inventive process without adhesive fillers can have larger amounts of filler than conventionally made paper, while retaining equal or superior strength characteristics.
  • filler is generally more economical than pulp fibers, the inventive process provides an economic benefit by a lower cost of goods for the finished paper composition.
  • it is less energy intensive and more economical to dry filler than to dry fiber.
  • reduced energy costs for paper forming will be achieved by reduced drying costs.
  • never-dried pulps are filled by consecutively soaking the never-dried pulp in solutions comprising a soluble salt or salts.
  • the never-dried pulps are first soaked in a first solution for approximately five minutes or less.
  • the first solution comprises a soluble salt or salts and functions to replace the water within the pores in the cell wall and in the lumen with a solution containing the soluble salt or salts of the first solution.
  • the never-dried pulp fibers are filtered and washed, which removes the salt or salts from the first solution from the exterior and the lumen of the fibers.
  • a second solution containing a different soluble salt or salts is added to the filtered fibers.
  • the interaction of the salt or salts from the first solution within the pores of the cell wall of the never-dried pulp fibers and the soluble salt or salts of the second solution forms an insoluble precipitate that falls out of solution within the pores of the cell wall of the never-dried pulp fibers.
  • the precipitate within the cell wall of the never-dried pulp fibers acts as a filler.
  • the insoluble precipitate acts as paper filler.
  • the filled, never-dried pulp fibers are subsequently filtered and washed and used to form paper.
  • the filled fibers may be dried and shipped to a papermaking facility as dry lap.
  • Pulp fibers are often beaten to certain specifications as part of the papermaking procedure.
  • the beating of the pulp fibers occurs before forming the paper.
  • the inventive process allows the beating to occur either before or after filling the fibers.
  • never-dried pulp fibers can be filled, dried and then beaten before use to form paper.
  • the order of the soluble salts in the first or the second solution is not important to the process. What is important is that the salt or salts of the first and second solution be different and that they form an insoluble precipitate upon interaction. Examples of white (opaque) and various colored precipitates are listed in Table 1.
  • soluble salts that form an insoluble precipitate include CaCl2 and Na2SiO3, yielding the precipitate CaSiO3 (an opaque white filler); BaCl2 and Na2SO4, yielding BaSO4 (a white opaque filler); and CaCl2 and Na2CO3, forming CaCO3 (opaque white filler). It should be noted that it is possible to replace a sodium cation with a potassium cation in any of the soluble salts.
  • green precipitate fillers are NiCO3, formed by the combination of the aqueous salts NiCl2 and Na2CO3; copper carbonate (CuCO3), from cuprous chloride (Cu2Cl2) and sodium carbonate; and chromic phosphate (CrPO4), from chromic chloride (CrCl3) and sodium phosphate (Na3PO4).
  • the preferred precipitate filler material is calcium carbonate (CaCO3). Calcium carbonate can be formed, for example, by having one solution of calcium chloride and the other solution of sodium or potassium carbonate. In all of the insoluble precipitates that are formed, the order of use of the soluble salts is not important.
  • the concentration of salt or salts in the aqueous solution can vary from about 1% to about 40%, depending upon the solubility of the salt in an aqueous system, the temperature of the process, and the amount of filler desired.
  • the concentration of salt or salts in the aqueous solution should be as saturated as the solubility characteristics and the temperature of the process permit so as to maximize the filler content of the resulting filled, never-dried pulp fibers.
  • the inventive process allows for the improved retention of mechanical properties of never-dried pulp when the cell wall is loaded with a precipitated filler in situ .
  • never-dried pulp was filled with NiCO3, formed from the soluble salts NiCl2 and NaCO3, the nickel precipitate can be visualized by electron dispersion analysis (EDAX).
  • Figure 1a shows the location of nickel
  • Figure 1b shows the nickel distribution.
  • the white dots in Figure 1b represent nickel, and the higher density of the white dots enables the fiber cell wall to be visualized.
  • Figures 2a, 2b and 2c show different aspects of a cross section of a never-dried pulp fiber loaded with nickel carbonate filler material by a process described herein.
  • Figure 2a shows the surface of the filled, never-dried pulp fibers with essentially zero nickel present in the third box from the right.
  • Figure 2b shows a high nickel level strongly above background in a peak in the third box from the right for the cell wall areas of the fibers.
  • Figure 2c shows the nickel concentration in the lumen of the filled, never-dried pulp fiber with very little nickel present.
  • Paper made from never-dried fibers that have been loaded in the cell wall pores with precipitate-type filler material can be used for a wide variety of applications. The following are some of the widest categories, bearing in mind there are also many specialty products which are produced in smaller quantities.
  • Fine papers are a broad class of papers used for printing and writing. Generally, fine papers contain fillers.
  • the paper made from cell wall filled, never-dried pulp exhibits less "two-sidedness.” Two-sidedness is due to an unequal distribution of filler across the thickness of the sheet. Further, there is less tendency for the filler to "dust off" from the sheet during the converting processes of wetting and slitting.
  • Unbleached kraft pulp is used for paper products such as paper bags and wrapping papers because of its high strength. However, it has a low brightness, thus making it both unattractive and a poor substrate for printing paper. None-dried, unbleached kraft pulp fibers with filled cell walls improve the brightness of the paper produced and less strength is lost from filler loading than with conventional loading techniques and dried pulp fibers.
  • This example illustrates a comparison using softwood never-dried pulp from western hemlock, comparing the properties of the paper made from the inventive process and a conventional process.
  • the pulp was beaten to 400 CSF before treatment.
  • a sample of never-dried pulp (10 g) was dispersed in a 5%, 10%, 20%, or 35% solution of CaCl2 in 500 ml of water.
  • the CaCl2-impregnated fibers were collected by filtration under reduced pressure and redispersed in a saturated Na2CO3 solution (1,000 ml). After one hour, the dispersion was filtered into a 76 ⁇ m nominal width of perture (200 mesh)wire screen and then washed with water until the filtrate was clear.
  • the conventionally filled pulp had its pH value of 8.0 adjusted using NaOH.
  • a retention aid (Reten® 210, Hercules Corp.) was added at various rates (0.226-0.680 kg/ 1000 kg(0.5-1.5 lb/ton) of pulp) to achieve the appropriate retention of the commercial CaCO3 slurry. The time of agitation was one minute.
  • Sheets were made with both the conventional, pulp and filler mixes and cell wall loaded, never-dried pulp by using TAPPI standard sheetmaking conditions.
  • the filler (CaCO3) content of the sheets was calculated by the ash content, as determined by the standard TAPPI procedure, except that the temperature of the furnace was 575°C.
  • Figure 3 shows the effect of filler level on the tensile index for conventional and cell wall loaded, never-dried pulp.
  • Figure 4 is a plot of the burst index versus filler concentration in the paper for both types of filled papers. These data demonstrate the superior burst strength values obtained using fibers filled by the inventive process.
  • the inventive process allows more filler to be added at the same paper strength or it provides for a higher level of strength at the same concentration of filler.
  • Filled paper sells for approximately $ 1,000/1000 kg ($ 1,000/ton) or $ 0.50/0.453 kg ($ 0.50/lb) when pulp costs $ 500/1000 kg ($ 500/ton) and filler costs $ 200/1000 kg ($ 200/ton).
  • every additional percent of filler that can be placed in a sheet instead of fiber represents a significant manufacturing cost savings of about $ 3-$ 4/1000kg ($ 3-$ 4/ton) to the papermaker.
  • the inventive process does not require a retention aid and thus the formation of the paper can be improved.
  • the inventive process improves the strength properties of the resulting paper.
  • This example illustrates a comparison of various mechanical properties of paper made with never-dried, cell wall loaded pulps from red alder versus never-dried red alder pulps combined with filler by conventional means versus once-dried red alder pulp fibers filled by the inventive process.
  • the never-dried pulps were initially beaten to 400 mL CSF prior to filler loading by either technique.
  • the methods used for filling red alder pulps by the inventive process or combining by the conventional techniques are described in Example 1.
  • Calcium carbonate was provided as a slurry for the conventional technique or precipitated in situ according to the inventive process.
  • the concentration of filler was determined from the ash content.
  • Figures 5, 6, and 7 compare the tear index, burst index, and tensile index, respectively, comparing red alder never-dried pulps filled by the inventive process or by the conventional technique.
  • the ash content indicates the percent of filler in the paper. Therefore, in each figure it is possible to compare the tear index, burst index, and tensile index of paper made from each type of filled fiber at equivalent filler concentrations.
  • the upper line with the higher tear burst or tensile indices is for papers made with fibers filled by the inventive process.
  • the squares represent never-dried pulp fibers filled wherein the sequence of solution addition is first calcium chloride followed by sodium carbonate and the circles have the reverse sequence of sodium carbonate followed by calcium chloride.
  • the lower line with the X-shaped points represents once-dried pulp fibers filled by the inventive process.
  • the lower line with the diamond points represents conventionally loaded, never-dried pulps.
  • the strength of the resulting paper was higher for the inventive process using never-dried pulp fibers. Further, the order of addition of the two solutions is not important.
  • This example illustrates a comparison of spruce CTMP (chemithermomechanical pulp) never-dried pulp fibers filled by the inventive process or by conventional techniques.
  • the never-dried fibers were initially beaten to 400 ml CSF.
  • the inventive process and the conventional process used to fill the fibers are described in Example 1.
  • Figures 8, 9, and 10 illustrate the tear index, burst index, and tensile index, respectively, of papers made from spruce CTMP never-dried pulp fibers filled by the inventive process and by the conventional technique.
  • the inventive process is illustrated by squares and the conventional admixture process by circles.
  • a characteristic of spruce CTMP pulp is that the tensile, burst, and tear indices decrease faster with increasing ash contents (i.e., increasing filler contents).
  • the paper made from never-dried pulp fibers filled by the inventive process demonstrated increased strength as compared with paper whose fibers were filled by conventional techniques.
  • This example compares bagasse pulps derived from sugarcane fibers comparing bleached and unbleached, never-dried pulps filled by the inventive method to bleached pulps that were once dried and filled by the inventive method to conventionally loaded bleached pulps.
  • the processes used to make each paper and to combine the fibers and the filler are described in Example 1.
  • Figures 11, 12, and 13 illustrate the tear index, burst index, and tensile index, respectively, of each of the three types of paper.
  • the squares illustrate the inventive process, wherein the data from paper made from bleached, never-dried pulp fibers are indicated by filled-in squares and unbleached, never-dried pulp fibers by open squares.
  • the data from paper made from never-dried bagasse fibers loaded by the conventional process is illustrated by the triangles.
  • the data from papers made from bleached, never-dried pulp fibers are shown by closed diamonds and unbleached, never-dried pulp fibers by open diamonds. Paper made from once-dried, bleached pulp and filled by the inventive process is shown by the triangles.
  • paper made with never-dried bagasse pulp fibers filled by the inventive process demonstrated superior strength characteristics at each concentration of filler tested.
  • FIG. 14 illustrates the relative decrease in tensile strength of paper expressed as a percentage versus the filler content expressed as a percentage with red alder never-dried pulps, bagasse never-dried pulps , and spruce CTMP never-dried pulps filled by the inventive process as compared with lumen-loading techniques using softwoods, as derived from Miller et al. in Proceedings 1983 TAPPI International Paper Physic Conference , Harwichport, p. 237 ("Miller et al.”),and Green et al., Pulp & Paper Canada , 83 :T203 (1982) ("Green et al.”).
  • PEI polyethyleneimine
  • the open circles indicate red alder never-dried pulps filled by the inventive process
  • the open diamonds represent bagasse pulps filled by the inventive process
  • the filled circles represent spruce CTMP never-dried pulps filled by the inventive process
  • the closed triangles represent the data in Miller et al.
  • the X figures represent the data in Green et al.
  • This example illustrates how never-dried eucalyptus pulp (a hardwood pulp) can be filled with aluminum hydroxide in situ .
  • Eucalyptus pulp was dispersed in a first solution containing the soluble salt aluminum sulfate.
  • the first solution contained a saturated concentration of aluminum sulfate at room temperature.
  • the first solution was removed after five minutes by filtering the pulp. This also removes the first solution from the pulp lumens.
  • a second solution containing 20% (w/v) sodium hydroxide was used to disperse the pulp fibers. This formed aluminum hydroxide precipitates predominantly in the cell wall of the fibers.
  • Paper was made from the fibers filled with aluminum hydroxide filler.
  • the amount of filler in the paper was 9% as determined by ash content of Al2O3 (alumina).
  • This example illustrates the effect of beating filled, never-dried fiber and the effect of different beating conditions.
  • Eucalyptus (hardwood) never-dried pulp was filled with CaCO3 by the inventive process as described herein.
  • the unbeaten, never-dried pulp had a Canadian Standard Freeness (CSF) of 570 ml.
  • CSF Canadian Standard Freeness
  • a sample of the filled, never-dried pulp fibers was first beaten for 10,000 revolutions in a PFI mill (beating apparatus). The CSF value was 416 ml.
  • the pulp was then formed into a crude first sheet by filtration onto a wire screen.
  • the ash content of the first sheet was 43%.
  • the pulp was then redispersed in water and refiltered to form a second sheet.
  • the ash content of the second sheet was 38%.
  • the entire procedure was repeated; except this time the filled, never-dried pulp fibers were first beaten for 20,000 revolutions, as described above.
  • the CSF value was 366 ml.
  • the first filtered sheet had 46% filler, the second sheet 41% filler, and the third sheet 38% filler. Thus, approximately only 8% filler was located outside of the cell wall even after beating for 20,000 revolutions.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Wood Science & Technology (AREA)
  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Paper (AREA)
  • Dry Formation Of Fiberboard And The Like (AREA)
  • Chemical And Physical Treatments For Wood And The Like (AREA)
  • Apparatus Associated With Microorganisms And Enzymes (AREA)
  • Seasonings (AREA)
  • Detergent Compositions (AREA)

Claims (9)

  1. Procédé de production d'une composition de fibres de pâte chargée, dans laquelle la pâte de départ est une pâte toujours humide provenant de bois durs ou feuillus, de bois tendres ou résineux, de plantes annuelles et de leurs combinaisons, procédé caractérisé en ce qu on immerge une pâte toujours humide, présentant un volume de pores de parois cellulaires internes tout en demeurant humide après formation de la pâte dans une première solution, la première solution comprenant un ou des sel(s) soluble(s),on filtre la pàte toujours humide et immergée pour enlever de l'extérieur de la fibre et de sa lumière le sel soluble puis l'on immerge à nouveau la pâte toujours humide dans une seconde solution, cette seconde solution comprenant un ou des sel(s) soluble(s) différent(s) du ou des sel(s) soluble(s) de la première solution, à la condition que l'interaction du ou des sel(s) de la première solution et du ou des sel(s) de la seconde solution forme un précipité insoluble jouant le rôle d'une charge de garnissage au sein de la paroi cellulaire de la pâte toujours humide ; et l'on filtre et lave la pâte toujours humide, ainsi chargée, pour former la fibre de pâte chargée.
  2. Procédé selon la revendication 1, dans lequel le précipité insoluble est choisi dans l'ensemble consistant en : CaO₃, AlPO₄, Zn(NH₄)PO₄, Mg(NH₄)PO₄, Ca(BO₂)₂, BiPO₄, MgCO₃, Zr(HPO₄)₂, ZrO(H₂PO₄), Al(OH)₃, Bi(OH)₃, Zn(OH)₂, Ti(OH)₄, Zr(OH)₄, CaSiO₃, BaSO₄, BaSiF₆, Ba(OH)₂, Ba₃(PO₄)₂, Ba₂P₄O₇, BaSiO₃, BaCO₃, BiO₂CO₃, CdCO₃, Ca(BO₂)₂.6H₂O, Ca(OH)₂, Ca₃(PO₄)₂, Ca₂P₂O₇.5H₂O, CaSO₄, PbCO₃, Mg(BO₂)₂.8H₂O, Mg(OH)₂, Mg₃(PO₄)₂, SrCO₃, SrSiO₃, SrSiO₄, Th(OH)₄, ZnCO₃, Zn₃(PO₄)₂.4H₂O, ZnSiO₃, Fe₄[Fe(CN)₆]₃, Fe₃[Fe(CN)₆]₂, Cu₃(PO₄)₂, Cu(OH)₂, CuCo₃Cu(OH)₂, CrPO₄.6H₂O, Hg₂I₂, HgI₂, AgCrO₄, BiI₂, BiI₃, CoCO₃, Co₃(PO₄)₂.8H₂O, Co[Fe(CN)₆]₂, Cu₂Fe(CN)₆.2H₂O, SnI₂, Co₃(PO₄)₂, Mn(NH₄)PO₄, Co₃(PO₄)₂.2H₂O, MnCO₃, CdS, CdMoO₄, BaCrO₄, Sb₂S₃, CaCrO₄.2H₂O, Cu₃[Fe(CN)₆]₂.14H₂O, PbCrO₄, PbI₂, Hg₂CO₃, Mo(PO₃)₆, AgI, Ag₃PO₄, SnS₂, Cr₄(P₂O₇)₃, Cu(BO₂)₂, CuCO₃Cu(OH)₂, Ni(PO₄)₂.8H₂O, NiCO₃, CrPO₄, CuS, et leurs combinaisons.
  3. Procédé selon la revendication 2, dans lequel le précipité insoluble est du carbonate de calcium.
  4. Fibre de pâte chargée, que l'on peut obtenir selon le procédé de la revendication 1, 2 ou 3, fibre caractérisée en ce qu'au moins 50 % de la charge contenue se situe au sein des pores de la paroi cellulaire de la fibre.
  5. Papier chargé, ayant une meilleure résistance mécanique et, comprenant une fibre de pâte chargée selon la revendication 4.
  6. Composition de papier selon la revendication 5, caractérisée en ce qu'elle comprend un agent colorant qui est un précipité coloré jouant le rôle d'une charge de garnissage.
  7. Composition de papier chargé selon la revendication 5, caractérisée en ce que, dans un papier kraft non blanchi, dans un papier kraft blanchi, dans un papier fin pour impression ou écriture et dans un papier journal léger, la quasi-totalité de la charge est située au sein de la paroi cellulaire des fibres.
  8. Procédé de production d'un papier chargé ayant une meilleure résistance mécanique, ce procédé comprenant la production d'une fibre de pâte chargée selon le procédé de la revendication 1, 2 ou 3, et la formation du papier avec la pâte chargée.
  9. Procédé selon la revendication 8, caractérisé en ce que le précipité insoluble formé est du carbonate de calcium, du sulfate de calcium, du phosphate de calcium, du silicate de calcium ou des combinaisons comportant au moins l'un de ces composés.
EP90911505A 1989-07-24 1990-07-24 Chargement de parois cellulaires de fibres de pate toujours humides Expired - Lifetime EP0484398B1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US38499289A 1989-07-24 1989-07-24
US384992 1989-07-24
PCT/US1990/004138 WO1991001409A1 (fr) 1989-07-24 1990-07-24 Chargement de parois cellulaires de fibres de pate toujours humides

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EP0484398A1 EP0484398A1 (fr) 1992-05-13
EP0484398B1 true EP0484398B1 (fr) 1994-09-21

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EP (1) EP0484398B1 (fr)
JP (1) JPH03152295A (fr)
AT (1) ATE111988T1 (fr)
AU (1) AU6141790A (fr)
CA (1) CA2063567C (fr)
DE (1) DE69012821T2 (fr)
FI (1) FI100196B (fr)
NO (1) NO177542C (fr)
WO (1) WO1991001409A1 (fr)

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US5223090A (en) * 1991-03-06 1993-06-29 The United States Of America As Represented By The Secretary Of Agriculture Method for fiber loading a chemical compound
US5275699A (en) * 1992-10-07 1994-01-04 University Of Washington Compositions and methods for filling dried cellulosic fibers with an inorganic filler
KR19980024075A (ko) * 1996-09-16 1998-07-06 퀴오그 매뉴엘 불용성 금속염을 사용하여 양이온성 염료, 음이온성 염료 및 안료 분산액을 부동화시키는 방법
US5928470A (en) * 1997-11-07 1999-07-27 Kimberly-Clark Worldwide, Inc. Method for filling and coating cellulose fibers
AU9505501A (en) 2000-10-04 2002-04-15 James Hardie Res Pty Ltd Fiber cement composite materials using cellulose fibers loaded with inorganic and/or organic substances
CA2424377C (fr) 2000-10-04 2013-07-09 Donald J. Merkley Materiaux composite de fibro-ciment utilisant des fibres cellulosiques calibrees
BR0114710A (pt) 2000-10-17 2003-11-18 James Hardie Res Pty Ltd Material de compósito de cimento de fibra empregando fibras de celulose duráveis tratadas por biocida
AU2007236561B2 (en) 2006-04-12 2012-12-20 James Hardie Technology Limited A surface sealed reinforced building element
DE102007018726A1 (de) * 2007-04-20 2008-10-23 Voith Patent Gmbh Verfahren zum Bilden von Füllstoffen, insbesondere Calciumcarbonat in einer Faserstoffsuspension
CN104179069B (zh) * 2014-08-18 2016-09-14 武汉地质资源环境工业技术研究院有限公司 一种抑制植物纤维衰变的造纸方法
CN108461784A (zh) * 2016-12-10 2018-08-28 中国科学院大连化学物理研究所 一种碱性锌铁液流电池
WO2018187238A1 (fr) 2017-04-03 2018-10-11 University Of Maryland, College Park Structures et dispositifs en bois flexibles et leurs procédés de fabrication et d'utilisation
US20180356127A1 (en) 2017-06-09 2018-12-13 University Of Maryland, College Park Wood-based solar thermal devices, and methods for fabrication and use thereof
EP3681682A4 (fr) 2017-09-15 2021-06-16 University of Maryland, College Park Matériaux de bois délignifié, et procédés de fabrication et d'utilisation desdits matériaux
CN115768947A (zh) * 2020-06-12 2023-03-07 特种矿物(密执安)有限公司 表面矿化有机纤维及其制造方法

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US4510020A (en) * 1980-06-12 1985-04-09 Pulp And Paper Research Institute Of Canada Lumen-loaded paper pulp, its production and use

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US2583548A (en) * 1948-03-17 1952-01-29 Vanderbilt Co R T Production of pigmented cellulosic pulp
US2599093A (en) * 1948-03-17 1952-06-03 Vanderbilt Co R T Pigmented cellulose fiber
SE455318B (sv) * 1985-01-15 1988-07-04 Mo Och Domsjoe Ab Sett for framstellning av papper innehallande lera eller andra fyllmedel

Patent Citations (1)

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Publication number Priority date Publication date Assignee Title
US4510020A (en) * 1980-06-12 1985-04-09 Pulp And Paper Research Institute Of Canada Lumen-loaded paper pulp, its production and use

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WO1991001409A1 (fr) 1991-02-07
AU6141790A (en) 1991-02-22
NO920327L (no) 1992-01-24
NO177542B (no) 1995-06-26
ATE111988T1 (de) 1994-10-15
DE69012821T2 (de) 1995-02-16
CA2063567C (fr) 2000-12-26
FI100196B (fi) 1997-10-15
NO177542C (no) 1995-10-04
EP0484398A1 (fr) 1992-05-13
FI920287A0 (fi) 1992-01-23
JPH03152295A (ja) 1991-06-28
DE69012821D1 (de) 1994-10-27
NO920327D0 (no) 1992-01-24
CA2063567A1 (fr) 1991-01-25

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