Abstract: The present invention relates to dry cellulose filaments and particularly those that are re-dispersible in water. Dry cellulose filaments comprise at least 50% by weight of the filaments having a filament length up to 350 ?m; and a diameter of between 100 and 500 nm, wherein the filaments are re-dispersible in water. Also described here is a film of dry cellulose filaments comprising the filaments described, wherein the film is dispersible in water. A method of making a dry film of cellulose filaments is also described that includes providing a liquid suspension of the cellulose filaments described; and retaining the filaments on the forming section of a paper or tissue making machine or on a modified paper or tissue making machine. The film can be optionally converted to powders or flakes for shipment, storage or subsequent uses. The filaments, the film, the powders or flakes and the method are in a preferred embodiment free of additives and the derivatization of the filaments.

Abstract: The present invention relates to dry cellulose filaments and particularly those that are re-dispersible in water. Dry cellulose filaments comprise at least 50% by weight of the filaments having a filament length up to 350 ?m; and a diameter of between 100 and 500 nm, wherein the filaments are re-dispersible in water. Also described here is a film of dry cellulose filaments comprising the filaments described, wherein the film is dispersible in water. A method of making a dry film of cellulose filaments is also described that includes providing a liquid suspension of the cellulose filaments described; and retaining the filaments on the forming section of a paper or tissue making machine or on a modified paper or tissue making machine. The film can be optionally converted to powders or flakes for shipment, storage or subsequent uses. The filaments, the film, the powders or flakes and the method are in a preferred embodiment free of additives and the derivatization of the filaments.

Abstract: A method for the production of cellulose films with at least one hydrophobic or less hydrophilic surface, or with at least one surface with a water contact angle (?) in a range from 55° to less than 100° is described. The method involves contacting the cellulose material with a hydrophobic solid material during the preparation of the cellulose films or with a vapour of a non-polar or polar aprotic solvent during or after the preparation of the cellulose films. Examples of the cellulose material are cellulose filaments (CF) made to have at least 50% by weight of the filaments having a filament length up to 350 ?m and a filament diameter between 100 and 500 nm from multi-pass, high consistency refining of wood or plant fibers, and commercially-available sodium carboxymethyl cellulose. Examples of the hydrophobic solid material are hydrophobic polymers, poly(methylpentene) and poly(ethylene). Examples of the non-polar solvent are hexane and toluene.

Abstract: A method for producing crystalline sulphated cellulose II materials with relatively low degree of polymerization from spent liquors of sulphuric acid (H2SO4) hydrolysis of cellulose has been discovered. The method involves: 1) separating the spent liquors from the hydrolysed, acid-insoluble, cellulose I materials by dilution from, for example, a 64% H2SO4 hydrolysis medium to a residual sulphuric acid concentration of 10-50% with 0-40% H2SO4, followed by settling (or centrifuging) and decanting; 2) adding the diluted spent liquors to water or heating the diluted spent liquors at 30-80° C. for ?48 h; and 3) recovering the recrystallized sulphated cellulose II materials with relatively low degree of polymerization either by filtration and washing or by washing and freeze drying. The method can be used to concurrently produce both crystalline, sulphated cellulose I and the crystalline, sulphated cellulose II materials.

Abstract: A method for producing crystalline sulphated cellulose II materials with relatively low degree of polymerization from spent liquors of sulphuric acid (H2SO4) hydrolysis of cellulose has been discovered. The method involves: 1) separating the spent liquors from the hydrolysed, acid-insoluble, cellulose I materials by dilution from, for example, a 64% H2SO4 hydrolysis medium to a residual sulphuric acid concentration of 10-50% with 0-40% H2SO4, followed by settling (or centrifuging) and decanting; 2) adding the diluted spent liquors to water or heating the diluted spent liquors at 30-80° C. for ?48 h; and 3) recovering the recrystallized sulphated cellulose II materials with relatively low degree of polymerization either by filtration and washing or by washing and freeze drying. The method can be used to concurrently produce both crystalline, sulphated cellulose I and the crystalline, sulphated cellulose II materials.

Abstract: Oxidized white liquor is heat treated to increase the concentration of polysulphide measured at 285 or 286 nm (PSUV) or measured at 416 nm (PSVIS) and the PSUV/PSGR or PSVIS/PSGR ratio, whereby the content of active polysulphide in the total polysulphide is increased which active polysulphide can be exploited to increase pulp yield in Kraft pulping.

Abstract: A method for the bleaching and brightness stabilization of lignocellulosic materials is described. The method involves the treatment of lignocellulosic materials, in particular, (a) wood pulps such as thermomechanical pulps (TMP) and chemithermomechanical pulps (CTMP), and (b) papers made from wood pulps, with a water-soluble phosphine or a phosphonium compound preferably containing at least one phosphorus hydroxyalkyl bond/linkage, for example a phosphorus hydroxymethyl bond/linkage (P—CH2OH). One example of such a water-soluble phosphine is the commercially available, tris(hydroxymethyl)phosphine (THP), P(CH2OH)3. One example of such a phosphonium compound is the commercially available, tetrakis(hydroxymethyl)phosphonium chloride (THPC), [P(CH2OH)4]Cl.

Abstract: A method for the bleaching and brightness stabilization of lignocellulosic materials is described. The method involves the treatment of lignocellulosic materials, in particular, (a) wood pulps such as thermomechanical pulps (TMP) and chemithermomechanical pulps (CTMP), and (b) papers made from wood pulps, with a water-soluble phosphine or a phosphonium compound preferably containing at least one phosphorus hydroxyalkyl bond/linkage, for example a phosphorus hydroxymethyl bond/linkage (P—CH2OH). One example of such a water-soluble phosphine is the commercially available, tris(hydroxymethyl)phosphine (THP), P(CH2OH)3. One example of such a phosphonium compound is the commercially available, tetrakis(hydroxymethyl)phosphonium chloride (THPC), [P(CH2OH)4]Cl.