1299results about "Cellulose pulp after-treatment modification" patented technology

An absorbent paper sheet for tissue or towel includes from about 99 percent to about 70 percent by weight of cellulosic papermaking fiber and from about 1 percent to about 30 percent by weight fibrillated regenerated cellulose microfiber which was regenerated form a cellulosic dope utilizing a tertiary amine N-oxide solvent or an ionic liquid. Fibrillation of the microfiber is controlled such that it has a reduced coarseness and a reduced freeness as compared with unfibrillated regenerated cellulose microfiber from which it is made and provides at least one of the following attributes to the absorbent sheet: (a) the absorbent sheet exhibits an elevated SAT value and an elevated wet tensile value as compared with a like sheet prepared without fibrillated regenerated cellulose microfiber; (b) the absorbent sheet exhibits an elevated wet / dry CD tensile ratio as compared with a like sheet prepared without fibrillated regenerated cellulose microfiber; (c) the absorbent sheet exhibits a lower GM Break Modulus than a like sheet having like tensile values prepared without fibrillated regenerated cellulose microfiber; or (d) the absorbent sheet exhibits an elevated bulk as compared with a like sheet having like tensile values prepared without fibrillated regenerated cellulose microfiber. In some embodiments, the pulp is pre-treated with debonder to enhance the wet / dry CD tensile ratio of the sheet.

The present invention relates to a paper or paperboard substrate having barrier properties which substrate comprises a first fiber based layer, a second layer comprising microfibrillated cellulose and a third layer comprising a polymer. The invention further relates to a process for the production of said substrate and a package formed of said substrate.

The present invention relates to a method of producing a cellulose based paper, the paper itself and the use thereof where the paper exhibits enhanced mechanical properties. The method involves providing a suspension of well dispersed modified cellulose at a low concentration. The properties and the chemical structure of the paper make it suitable for in vivo applications such as implant material.

A process for making nanofibers includes preparing a fluid suspension of fibers, shear refining the fibers to create fibrillated fibers, and subsequently closed channel refining or homogenizing the fibrillated fibers to detach nanofibers from the fibrillated fibers. The shear refining of the fibers in the fluid suspension generates fiber cores having attached nanofibers. The closed channel refining or homogenizing of the fibrillated fibers is initially at a first shear rate and, subsequently, at a second, higher shear rate, to detach nanofibers from fiber cores and to create additional nanofibers from the fiber cores. The fiber suspension may flow continuously from the shear refining to the closed channel refining or homogenizing, and include controlling the rate of flow of the fiber suspension from the shear refining to the closed channel refining or homogenizing.

Disclosed is a method for removing minerals from a cellulosic biomass. For example, the biomass may be prewashed with an acid solution and rinsed with water to remove minerals prior to acid saccharification. The removal of minerals may reduce overall acid requirements, and decrease pretreatment costs.

An authenticatable paper product is prepared by adding to a papermaking furnish fibers treated with from about 50-200 lb / ton of a fluorescent whitening agent (FWA). The paper made from the papermaking furnish will include fluorescent cellulosic fibers in an amount ranging from between 0.1-4.0 lb / ton to achieve FWA concentrations within the range of 1-20 ppm.

A method to produce on a commercial scale, high aspect ratio cellulose nanofilaments (CNF) from natural lignocellulosic fibers comprises a multi-pass high consistency refining (HCR) of chemical or mechanical fibers using combinations of refining intensity and specific energy. The CNF produced represents a mixture of fine filaments with widths in the submicron and lengths from tens of micrometers to few millimeters. The product has a population of free filaments and filaments bound to the fiber core from which they were produced. The proportion of free and bound filaments is governed in large part by total specific energy applied to the pulp in the refiner, and differs from other cellulose fibrillar materials by their higher aspect ratio and the preserved degree of polymerization (DP) of cellulose, and are excellent additives for the reinforcement of paper, tissue, paperboard and the like. They display exceptional strengthening power for never-dried paper webs.

Methods for forming an absorbent fibrous composite containing absorbent material dispersed in bands through the composite and along the composite's length are disclosed. The methods generally include depositing a fibrous slurry on a foraminous support to form a web and depositing or injecting absorbent material into the web across its width to provide a web having absorbent material in bands along the composite's length. Drying the web provides a fluted absorbent composite. In one embodiment, the method is a wetlaid method and in another embodiment, the method is a foam-forming method. Preferably, the methods are twin-wire forming methods.

An absorbent composite (10) having a fibrous matrix that includes absorbent material is disclosed. The fibrous matrix defines voids (14) and passages between the voids, which are distributed throughout the composite. Absorbent material (18) is located within some of the voids (14). Absorbent material located in these voids is expandable into the void. In a preferred embodiment, the composite's fibrous matrix includes resilient and matrix fibers (16). The composite optionally includes a wet strength agent.

The present invention relates to a polysaccharide having functional groups, wherein said groups are aldehyde groups formed at positions C2 and / or C3 as well as at position C6 of the anhydroglucose units of the polysaccharide chain. Preferably the polysaccharide is a cellulosic fibrous material whose primary and secondary hydroxyl groups of the cellulose are oxidized into aldehyde groups at least in part by means of TEMPO oxidation and periodate oxidation.The invention also concerns a paper or nonwoven comprising the above polysaccharide. According to the invention a relative wet strength of more than 10% can be achieved.

An absorbent paper sheet for tissue or towel includes from about 99 percent to about 70 percent by weight of cellulosic papermaking fiber and from about 1 percent to about 30 percent by weight fibrillated regenerated cellulose microfiber which was regenerated form a cellulosic dope utilizing a tertiary amine N-oxide solvent or an ionic liquid. Fibrillation of the microfiber is controlled such that it has a reduced coarseness and a reduced freeness as compared with unfibrillated regenerated cellulose microfiber from which it is made and provides at least one of the following attributes to the absorbent sheet: (a) the absorbent sheet exhibits an elevated SAT value and an elevated wet tensile value as compared with a like sheet prepared without fibrillated regenerated cellulose microfiber; (b) the absorbent sheet exhibits an elevated wet / dry CD tensile ratio as compared with a like sheet prepared without fibrillated regenerated cellulose microfiber; (c) the absorbent sheet exhibits a lower GM Break Modulus than a like sheet having like tensile values prepared without fibrillated regenerated cellulose microfiber; or (d) the absorbent sheet exhibits an elevated bulk as compared with a like sheet having like tensile values prepared without fibrillated regenerated cellulose microfiber. In some embodiments, the pulp is pre-treated with debonder to enhance the wet / dry CD tensile ratio of the sheet.

A process comprising treating a lignocellulosic material preferably pulp in the presence of a transition metal catalyst with a oxidizing agent selected from a group consisting of hydrogen peroxide, hypochlorite, hypochlorous acid and any combination thereof to form a treated lignocellulosic material having a viscosity equal to or less than about 17 cp and having reducing functional groups selected from the group consisting of aldehyde and aldehyde type functional groups at the C6 and C1 positions but predominating at the C1 position.

A method of making regenerated cellulose microfibers includes forming segmented fibers with multiple longitudinally-extending segments of slightly different composition such that there is defined splittable interfaces between juxtaposed segments of the fibers which are then split into microfibers at yields of greater than 50%. Fibers so produced may be incorporated into absorbent sheet with other papermaking fibers to provide strength, softness, bulk and absorbency to tissue, towel, and personal care products.

The cellulose nanofiber production method of the present invention comprises an oxidation treatment step for oxidizing native cellulose in a neutral or acidic reaction solution containing an N-oxyl compound and an oxidizing agent that oxidizes aldehyde groups, and a dispersion step for dispersing the native cellulose in a medium following the oxidation treatment step. According to the production method of the present invention, a cellulose nanofiber is provided that has long fibers and demonstrates high strength.

A method to prepare aqueous furnishes useful as feedstock in the manufacture of very high-mineral content products, particularly paper sheets having mineral filler content up to 90% that display the required physical properties for the intended applications; the furnishes comprise fibrillated long fibres / mineral fillers mixed with anionic acrylic binders and co-additives, in presence or absence of cellulose fibrils; the fibrillated long fibres and cellulose fibrils provide high surface area for greater filler fixation and the reinforcement backbone network that ties all of the product components together; the anionic binders allow rapid and strong fixation of filler particles onto the surfaces of fibrils when mixing is conducted at temperatures higher than the glass transition temperature (Tg) of the binder. The aqueous furnish provides excellent filler retention and drainage during product fabrication.

A method for treatment of chemical pulp for the manufacturing of microfibrillated cellulose includes the following steps: a) providing a hemicellulose containing pulp, b) refining the pulp in at least one step and treating the pulp with one or more wood degrading enzymes at a relatively low enzyme dosage, and c) homogenizing the pulp thus providing the microfibrillated cellulose. According to a second aspect of the invention a microfibrillated cellulose obtainable by the method according to the first aspect is provided. According to a third aspect of the invention, use of the microfibrillated cellulose according to the second aspect in food products, paper products, composite materials, coatings or in rheology modifiers (e.g. drilling muds) is provided.

The present invention is directed to a process for producing micropulp. The process includes contacting organic fibers with a medium comprising a liquid component and a solid component, agitating the medium and the organic fibers to transform the organic fibers into the micropulp dispersed in the medium. If desired, the slurry of the micropulp in the liquid component can be used or the micropulp can be separated from the medium. The micropulp can be readily incorporated into coating compositions such as those used in automotive OEM or refinish applications. The micropulp can also be incorporated into powder coating applications or as a thixotrope or reinforcement in polymer formulations.

The present invention aims to provide cellulose-based fibrous materials for obtaining papers and sheets having low density, high surface quality, good size stability despite of high strength, and high opacity. Cellulose-based fibrous materials having external fibrils consisting of an assembly of scale-like microfibrils exhibit a higher fiber stiffness, a lower water retention value and a higher specific surface area as compared with fibrous materials having filamentous external fibrils at the same freeness. Papers and sheets having low density, high surface quality, good size stability and high opacity can be obtained by using such fibrous materials.

An absorbent composite (10) having a fibrous matrix that includes absorbent material is disclosed. The fibrous matrix defines voids (14) and passages between the voids, which are distributed throughout the composite. Absorbent material (18) is located within some of the voids (14). Absorbent material located in these voids is expandable into the void. In a preferred embodiment, the composite's fibrous matrix includes resilient and matrix fibers (16). The composite optionally includes a wet strength agent.

The present invention relates to a paper or paperboard product comprising a furnish wherein said furnish comprises a cationic polymer in an amount of above 1.5% by weight, an anionic polymer and microfibrillated cellulose. The invention further relates to a process for the production of said product.

Paper or paperboard laminate composed of at least one bulk-promoting layer, here termed the bulk layer, and on at least one side at the bulk layer at least one secondary layer, secondary layer and bulk layer being joined to one another directly or indirectly over basically the whole of their surfaces facing one another, 40-95% of the bulk layer consists of cellulose fibers with a freeness of 550-950 ml CSF, the secondary layer / layers has / have a greater density than the bulk layer, and the laminate has a bending stiffness index higher than 2.5 Nm7 / kg3, but less than 14 Nm7 / kg3, calculated as a geometric mean value for machine and transverse direction.

The present invention aims to provide cellulose-based fibrous materials for obtaining papers and sheets having low density, high surface quality, good size stability despite of high strength, and high opacity. Cellulose-based fibrous materials having external fibrils consisting of an assembly of scale-like microfibrils exhibit a higher fiber stiffness, a lower water retention value and a higher specific surface area as compared with fibrous materials having filamentous external fibrils at the same freeness. Papers and sheets having low density, high surface quality, good size stability and high opacity can be obtained by using such fibrous materials.

The present invention aims to provide a process for producing cellulose nanofibers using a 4-hydroxy TEMPO derivative less expensive than TEMPO and a process capable of rapidly producing homogeneous cellulose nanofibers. Wood cellulose can be efficiently converted into nanofibers by a process for producing cellulose nanofibers comprising treating a cellulosic material with an oxidizing agent in water in the presence of a cellulose oxidation catalyst comprising an N-oxyl compound represented by formula 1 below:wherein R1 and R2 are each independently hydrogen or a C1-C6 straight or branched alkyl group; and(i) one of R4 or R5 is —OR, —OCOR or —OSO2R wherein R is a straight or branched carbon chain having 4 or less carbon atoms, and the other of R4 or R5 is hydrogen, and R3 and R6 are methyl, or(ii) R4 is hydrogen, and R5, R3 and R6 are taken together with a piperidine ring to form an aza-adamantane compound having formula 2 below:or a mixture thereof, and a compound selected from the group consisting of bromides, iodides and mixtures thereof to prepare oxidized cellulose, and microfibrillating the oxidized cellulose to convert it into nanofibers.

The present invention provides a method for producing modified nanofibrillated cellulose characterized by bringing cellulosic material into a fiber suspension, adsorbing a cellulose derivative or polysaccharide or polysaccharide derivative onto fibers in said fiber suspension under special conditions and subjecting the obtained fiber suspension derivative to mechanical disintegration. A modified nanofibrillated cellulose obtainable by a method of the present invention is provided. Furthermore, the invention relates to the use of said modified nanotibrillated cellulose.

The invention relates to a method of producing a laminate paper product comprising at least two layers, said method comprising (i) providing an aqueous suspension comprising cellulosic fibers (ii) adding to the suspension microfibrillar polysaccharide in an amount to yield from about 0.05 to about 50 wt % based on the weight of the cellulosic fibers (iii) dewatering the obtained suspension and forming a first layer having a density from about 150 to about 500 kg / m3 of said laminate paper product. The invention also relates to a method comprising (i) providing an aqueous suspension comprising cellulosic fibers (ii) adding to the suspension microfibrillar polysaccharide in an amount to yield from about 0.05 to about 50 wt % based on the weight of the cellulosic fibers (iii) dewatering the obtained suspension and forming at least a first and a second layer of said laminate whereby at least one of said at least first and second layer is formed from an aqueous suspension obtained in step (ii) containing microfibrillar polysaccharide; and joining said layers in such way that the laminate product obtains a density from about 150 to about 800 kg / m3. The invention also relates to a laminate paper product which can be obtained by the method and the use thereof.

Processes disclosed are capable of converting biomass into high-crystallinity nanocellulose with surprisingly low mechanical energy input. In some variations, the process includes fractionating biomass with an acid (such as sulfur dioxide), a solvent (such as ethanol), and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin; and mechanically treating the cellulose-rich solids to form nanofibrils and / or nanocrystals. The total mechanical energy may be less than 500 kilowatt-hours per ton. The crystallinity of the nanocellulose material may be 80% or higher, translating into good reinforcing properties for composites. The nanocellulose material may include nanofibrillated cellulose, nanocrystalline cellulose, or both. In some embodiments, the nanocellulose material is hydrophobic via deposition of some lignin onto the cellulose surface. Optionally, sugars derived from amorphous cellulose and hemicellulose may be separately fermented, such as to monomers for various polymers. These polymers may be combined with the nanocellulose to form completely renewable composites.

A method of making absorbent cellulosic sheet includes forming a web of papermaking fibers, extruding a cellulosic dope of underivatized cellulose, disposing the dope upon the web and regenerating the cellulose in-situ. Regenerated filaments may have a denier of from about 0.05 to about 20.

The present invention relates to a filler-fiber composite, a process for its production, the use of such in the manufacture of paper or paperboard products and to paper produced therefrom. More particularly the invention relates to a filler-fiber composite in which the morphology and particle size of the mineral filler are established prior to the development of the bond to the fiber. Even more particularly, the present invention relates to a PCC filler-fiber composite, wherein the desired optical and physical properties of the paper produced therefrom are realized.

The present invention relates to the production of texturized microcrystalline cellulose from raw pulp material. This texturized microcrystalline cellulose can then be used for surface treatment of paper or paper board. Additionally, the texturized microcrystalline cellulose may be used as a starting material for production of paper or paper board.