Abstract: A process for bleaching chemical pulp for paper manufacturing comprising delignifying and bleaching chemical pulp which has been treated by cooking by simultaneous use of chlorine dioxide, a peroxide, and at least one reaction catalyst selected from the group consisting of oxoacids of elements of Groups IV, V and VI and salts of these acids. Formation of organic chlorine compounds as by-products is suppressed by decreasing the amount of chlorine dioxide used in the ECF bleaching process in the first stage, and thus environmental toxicity in the waste water discharged from the bleaching process is decreased. Chemical pulp having a high degree of brightness is economically produced because increase in the production capacity is not required at all or suppressed to the minimum, and the investment cost is reduced to the minimum when the bleaching with chlorine in the first stage is converted into the bleaching with chlorine dioxide which is an ECF bleaching process.

Abstract: A process for final bleaching cellulose-containing pulp which has been subjected to previous bleaching with a peroxide compound. The process involves the sequential steps of exposing the pulp to an amount of a reducing agent in order to eliminate residual peroxide compound from the pulp and then final bleaching the pulp by exposing the pulp to an amount of formamidine sulfinic acid.

Abstract: A multi-ply paperboard comprising at least one ply of conventional cellulose fibers and from about 0.1 to about 6 weight percent of a water-borne binding agent; and at least one ply of chemically intrafiber crosslinked cellulosic high-bulk fibers and from about 0.1 to about 6 weight percent of a water-borne binding agent. The water-borne binding agent may be a starch, a modified starch, a polyvinyl alcohol, a polyvinyl acetate, a polyethylene/acrylic acid copolymer, an acrylic acid polymer, a polyacrylate, a polyacrylamide, a polyamine, guar gum, an oxidized polyethylene, a polyvinyl chloride, a polyvinyl chloride/acrylic acid copolymer, an acrylonitrile/ butadiene/styrene copolymer or polyacrylonitrile. A method for making the paperboard is disclosed.

Abstract: A process for the production of pulp using alkaline delignification is disclosed, wherein cellulosic material is initially treated with steam, and a chelating agent is added in connection with the steam treatment. The end pH of the steam treatment stage is below 5. Liquors containing chelated, so-called non-process compounds are not recycled in the pulping process, but expelled therefrom for further processing where non-process compounds are eliminated.

Abstract: A process for delignification and bleaching of chemically digested lignocellulose-containing pulp. In a first embodiment, the pulp is acid treated at a pH of between about 1 and about 6, whereupon a water-soluble compound containing an alkaline earth metal is added at a pH of between about 1 and about 7 before the pulp is treated with a chlorine-free bleaching agent. In a second embodiment, the acid and alkaline earth metal treatments are carried out in a single step. The chlorine-free bleaching agent includes peroxide compounds, ozone, oxygen and sodium dithionite in an optional sequence or mixture. After the treatment according to the invention, the pulp may be finally bleached to the desired brightness, suitably with a chlorine-free bleaching agent, such as ozone, to completely avoid formation and discharge of AOX.

Abstract: A novel process has been discovered whereby acid is added to the lignocellulosic material (black liquor containing lignin). The acid renders the lignin insoluble thus enabling it to be separated from the lignocellulosic material. This allows the chemical value of various components to be reclaimed. This process enables important environmental and economic benefits to be achieved. The invention obviates the need for a recovery boiler which burns the sugars and the lignin. Additionally, sodium salts are precipitated out of the process. Sodium carbonate from outside sources is used in the novel process. The supply of energy to the separation process is from a source other than the recovery furnace.

Abstract: A method of bleaching chemical cellulose pulp from an alkaline (e.g. kraft) pulping process in a chlorine dioxide stage includes (without between step washing) bleaching the pulp in a first chlorine dioxide step, and adjusting the pH of the pulp in the first chlorine dioxide step so that the final pH of the step is over 4; and then (b) effecting acid treatment of the chemical cellulose pulp at a pH of between 2-5 (preferably 2.5-4) and a temperature of over 80° C. (preferably between about 90-110° C.). The temperature in the first chlorine dioxide stage is preferably over 75° C., e.g. between about 80-100° C., and for a time of less than ten minutes, with a chlorine dioxide dosage of between about 0.5-1.5% active chlorine. Preferably a second chlorine dioxide step is practiced after the acid treatment, preferably at substantially the same conditions as the first chlorine dioxide step.

Abstract: In a method and apparatus for treating pulp, a peroxide treatment of chemical pulp, i.e., both sulphite pulp and kraft pulp, is used to quickly reduce the Kappa number of the pulp. The method involves treating a chemical pulp with at least hydrogen peroxide or its equivalent, the kappa number of which chemical pulp has been brought to a level below 20 by either at least cooking or cooking and delignifying. The pulp is treated in a fast alkaline or neutral peroxide stage (Pk) (e.g. a small reactor having a volume of, or proportional to, less than about 90 cubic meters for 1500 tons per day pulp treatment) to reduce the kappa number by 1-10 units, and preferably by 3-7 kappa units, in which treatment the reaction time is less than 10 minutes, and is preferably less than 5 minutes. The pulp is then transferred substantially without intermediate washing of any type to a bleaching tower, and then bleached further in an acidic bleaching step (e.g. a D or Z step) in the bleaching tower.

Abstract: A process for producing fibrous materials for the manufacture of cellulose, paper or wood materials by using at least one dicarboxylic acid dialkyl ester and/or a copolymer of polyester-polyether and/or fatty acid polyol monopolyester, dipolyester, tripolyester and or higher polyester. Fibrous materials with an improved quality and higher yield are thus produced.

Abstract: An aqueous alkaline slurry of cellulose pulp is bleached with oxygen or peroxide by using a compound represented by general formula (1), (2) or (3) as a bleaching assistant: R1—O—[(C2H4O)m/(AO)n]—H  (1) R2—O—[(C2H4O)m/(AO)p]—(AO)q—H  (2) (R3)t—X—[(C2H4O)m/(AO)p]—(AO)r—H  (3) where R1 stands for a branched alkyl group having 6 to 12 carbon atoms, m stands for an average added mol number of 4 to 15, A stands for a propylene, butylene or phenylethylene group, n stands for an average added mol number of 0 to 4, the addition shown in [ ] is in a random or block form, R2 stands for a linear or branched alkyl group having 6 to 12 carbon atoms, p stands for an average added mol number of 0 to 3.9, q stands for an average added mol number of 0.

Abstract: The present invention relates to a process for producing pulp which is cooked under alkaline conditions and which is bleached without using chlorine-containing bleaching chemicals, in which process used cooking chemicals are recovered in a first recovery installation and used bleaching chemicals are recovered in a second recovery installation. The used cooking and bleaching chemicals can be regenerated and reused.

Abstract: A process for bleaching pulp, in which, after fiber liberation, a first filtrate containing metals, principally in ionic form, is separated off from the pulp, and supplied downstream to the pulp flow after a bleaching stage.

Abstract: The invention concerns buccodental formulation characterized in that it comprises at least a thickening agent comprising cellulose nanofibrils, said cellulose nanofibrils being substantially amorphous, having a crystallinity index not more than 50%. The invention also concerns said cellulose nanofibrils as thickening agent and/or flavour enhancer in buccodental formulations.

Abstract: This invention relates to compositions, paper, thermoplastic sheets, and medical paper containing cellulose ester, alkylpolyglycoside (APG) or a mixture of APG and polyether glycol, and, optionally, cellulose. The process of incorporating APG or a mixture of APG and polyether glycol in paper composed of cellulose ester fibers and cellulose fibers and to calendaring of such paper is also disclosed.

Abstract: In the treatment of cellulose pulp in connection with bleaching, the pulp is first cooked and, if necessary, oxygen delignified in order to reduce the Kappa number below 24, preferably below 14, and after that the pulp is treated in an acid stage at a pH of 2-5 and at a temperature range of 75-130° C. in order to reduce the Kappa number by 2-9 units. To prevent essential weakening of the strength properties of the pulp in the acid stage treatment tower, the retention time, t min, is 30 to 300 minutes and the treatment temperature, T° C. is Tmin<T<Tmax, in which T min = 10517 24 + ln ⁡ ( 2 ⁢ t ) - 273 and Tmax=Tmin+23° C.

Abstract: Multi-component system for modifying, degrading or bleaching lignin, lignin-containing materials or similar substances, includes

Abstract: An aqueous alkaline slurry of cellulose pulp is bleached with oxygen or peroxide by using a compound represented by general formula (1), (2) or (3) as a bleaching assistant:

Abstract: A paper bulking promoter containing a compound represented by the following formula (1) with which a highly bulky sheet can be obtained without impairing paper strength: RO(EO)m(PO)nH  (1) wherein R represents a linear or branched alkyl or alkenyl group having 6 to 22 carbon atoms or an alkylaryl group in which the alkyl group has 4 to 20 carbon atoms; E represents an ethylene group; P represents a propylene group; m indicates the average number of moles added in the range of 0≦m≦20; and n is a number in the range of 0≦n≦50; provided that the EO and PO groups may have any of block and random arrangements and may begin with any of EO and PO.

Abstract: A process for the bleaching of chemical pulp, in which process the pulp is delignified with a peracid and additionally the pulp is chelated in order to bind heavy metals, such as Fe, Mn and/or Cu, into a chelate complex. According to the invention, the chelating is carried out using a chemical which has been selected from a group consisting of N-bis-((1,2-dicarboxy-ethoxy)-ethyl)-amine, N-bis-((1,2-dicarboxy-ethoxy)-ethyl)-aspartic acid and N-tris-((1,2-dicarboxy-ethoxy)-ethyl)-amine, as well as the alkali metal and earth-alkali metal salts thereof, and the peracid and chelating treatments are carried out simultaneously by combining the peracid and the said chelating chemical in the same solution phase. In the bleaching sequence the treatment according to the invention may follow, for example, an ozone delignification and precede an alkaline peroxide step, and in the latter case a magnesium compound, such as MgSO4, may be added to the pulp before the alkali step.

Abstract: A method for the manufacture of bleached cellulose pulp, in conjunction with which lignocellulose material is digested to form cellulose pulp by means of an alkaline digestion liquor, and the cellulose pulp in the form of a suspension is screened, if necessary, and subjected in series to at least oxygen gas delignification/bleaching (O), if required, chlorine dioxide bleaching (D) and bleaching with non chlorine-containing, oxidative bleaching agent (O, P, Z), with the various bleaching stages interspersed with washing and/or reconcentration of the cellulose pulp in at least one stage, characterized in that complexing agents are added to the cellulose pulp in conjunction with the chlorine dioxide bleaching. It is also important for the mol quotient of the cellulose pulp for magnesium/manganese, during bleaching with a non chlorine-containing, oxidative bleaching agent, to be maintained at or brought to a value exceeding 20, and preferably exceeding 40.

Abstract: Multi-component system for modifying, degrading or bleaching lignin, lignin-containing materials or similar substances, includes (a) if appropriate at least one oxidation catalyst; (b) at least one suitable oxidizing agent; and (c) at least one mediator, wherein the mediator is chosen from the group consisting of N-aryl-N-hydroxyamides.

Abstract: Pulps or papers, especially chemimechanical or thermomechanical pulps or papers, which still contain lignin, have enhanced resistance to yellowing when they contain an effective stabilizing amount of a hindered amine compound which preferably is a nitroxide, a hydroxylamine or an ammonium salt thereof. This performance is often further enhanced by the presence of one or more coadditives selected from the group consisting of the UV absorbers, the polymeric inhibitors, the nitrones, the fluorescent whitening agents, metal chelating agents, sulfur containing stabilizers, metal salts and diene compounds. Combinations of nitroxides, hydroxylamines or their salts, benzotriazole or benzophenone UV absorbers and a metal chelating agent are particularly effective. Selected derivatives of 1-oxyl-2,2,6,6-tetramethyl-piperidin-4-ol and selected hydroxylamine salts are novel compounds and are surprisingly effective for this purpose.

Abstract: The invention relates to a method for removing chemically bound formic acid from a material containing the same, in the presence of free formic acid. The method is characterized in that chemically bound formic acid is allowed to react to free formic acid at a normal pressure, at a temperature of less than 100° C., the initial contact free formic acid being about 3 to 20%. The reaction time is typically 0.5 to 4 hours. The material to be treated may be, for instance, material, obtained from a formic-acid-based pulp cooking process, containing cellulose and/or lignin.

Abstract: Chemical cellulose pulp (e.g. kraft pulp) is produced with enhanced strength and/or yield using a strength or yield enhancing additive such as polysulfide or anthraquinone or its equivalents or derivatives, and in a manner that allows effective recovery/reuse of the additive so as to make the process more economical. In a continuous digester a low temperature and relatively low alkalinity protecting zone is provided at the top of the digester terminating with a first screen, and a second screen is provided below the first screen. Between the first and second screens, prior to bulk delignification, a first counter-current zone is provided, and additive-containing liquid from the first screen is recirculated to the slurry at or near the digester inlet to enhance yield or strength.

Abstract: This process involves feeding cellulose into an extruder with an acid solution. The extruder is comprised of a screw and a barrel. The screw is rotated so as to pressurize the cellulose, and the cellulose undergoes acid hydrolysis and forms microcrystalline cellulose. The invented process can be accomplished by using pure cellulose or a lignocellulosic material as the starting material. If a lignocellulosic material is used, then a basic solution is added to it and the lignocellulosic material is fed through an extruder so as to obtain a mixture comprising lignin, hemicellulose and cellulose. The lignin and hemicellulose are extracted and the remaining cellulose is processed, as discussed previously, to form microcrystalline cellulose.

Abstract: Process for bleaching a chemical paper pulp to a brightness of at least 89° ISO, consisting in subjecting the pulp to a treatment sequence of several stages including a final bleaching stage with hydrogen peroxide in alkaline medium carried out in the presence of at least one stabilising agent and at a consistency of at least 25% by weight of solids, the stages preceding this final stage having purified the pulp so that its manganese content does not exceed 3 ppm by weight with respect to the solids and that the pulp has been delignified beforehand to a kappa number not exceeding 5.

Abstract: A process for the preparation of iminodisuccinic acid alkali metal salts by reaction of maleic acid and ammonia in an aqueous medium in the presence of alkali metal hydroxides and working up thereof.

Abstract: Amphoteric derivatives of aliphatic polyamines, such as diethylenetriamine or triethylenetetramine reacted with long chain fatty acids, esters or triglycerides from various natural or synthetic sources are effective in the softening/texture modification of substrates such as paper, textiles, human skin surfaces and hair tresses, as well as in applications for metal working and lubrication. The polyamines are first reacted with fatty acids, esters or triglycerides derived from various animal, vegetable or synthetic sources ranging in molecular distribution from butyric through erucic acids (e.g. milkfat, soy bean oil, rapeseed oil) to form polyamines or imidazolines; they are then further reacted with unsaturated or halogenated carboxylic acids, carboxylated epoxy compounds or acid anhydrides (e.g. acrylic acid, itaconic acid, chloroacetic acid, maleic anhydrides octadecenyl anhydride) to form the various amphoteric structures.

Abstract: This invention relates to compositions, paper, thermoplastic sheets, and medical paper containing cellulose ester, alkylpolyglycoside (APG) or a mixture of APG and polyether glycol, and, optionally, cellulose. The process of incorporating APG or a mixture of APG and polyether glycol in paper composed of cellulose ester fibers and cellulose fibers and to calendaring of such paper is also disclosed.

Abstract: A process for production of a lignocellulosic material modified by conjugation thereto of a phenolic substance comprising a substituent which, in the conjugated form of the phenolic substance, is, or may become, negatively or positively charged, respectively, comprises: reacting a lignocellulosic fibre material and the phenolic substance with an oxidizing agent in the presence of an enzyme capable of catalyzing the oxidation of phenolic groups by the oxidizing agent; and reacting together the products of the reactions; with the proviso that the phenolic substance is not a phenolic polysaccharide. A strengthened lignocellulose-based product (e.g. a paper product) may be prepared by a procedure wherein a product produced in accordance with the latter process is treated with a strengthening agent having an ionic charge of sign opposite to that which is conferred on the modified lignocellulosic material by the charge-conferring substituent.

Abstract: A process for producing a pulp from cellulose-containing material, wherein the material is reacted with formic acid as the solvent, and cooked at approximately the boiling temperature of the solvent, whereby return condensation is used. Annual plants, deciduous or coniferous wood can be used as the cellulose-containing material. In one variant of the process, the cellulose-containing material is only slightly warmed, whereby backflow cooling is used, and then a precisely predetermined quantity of hydrogen peroxide is slowly added to the liquid at a constant rate. This process variant can be repeated at a lower cooking temperature. The pulp thus obtained is preferably utilized in the production of cellulose, and in particular in the production of paper or cardboard. It is proposed that the lignin, which is isolated from the cellulose-containing material, have further applications, whereby such lignin is, after the pulp has been separated from the solvent, itself precipitated out in water.

Abstract: A process for the delignification of a chemical pulp, such as a sulfate or sulfite pulp, in which process the pulp is treated with a peroxide and/or a peracid in the presence of an activating Ti-, V- or Cr-group transition metal, such as molybdenum, vanadium or tungsten. A compound containing at least one heteroatom, such as Si, P or B, which is capable of forming a heteropolyacid with the activating transition metal, is added to the pulp. The feeding of the activating transition metal and the heteroatom into the pulp may take place in one and the same alkaline solution, for example introduced into the solution or in the form of a compound of the silicomolybdenic acid type, formed in the solution. The peroxide and/or peracid treatment may constitute part of the bleaching sequence, which contains as potential other treatment steps, for example, a treatment with oxygen and a chelation for the removal of heavy metals such as iron, manganese and/or copper.

Abstract: The invention relates to a method of producing pulp with a high brightness using single-stage cooking with formic acid, washing with performic acid and bleaching with oxidizing bleaching chemicals. In performic acid washing, the rapid formation and rapid reactions of performic acid (HCOOOH) are utilitized for modification of residual lignin. The method of the invention provides an ISO brightness exceeding 90% without a chlorine chemicals. The method can be applied to both herbaceous plants and wood.

Abstract: A process for chlorine-free bleaching of chemical pulp in association with the production thereof, where a suspension of the pulp preferably has a concentration exceeding 8% of cellulose-containing fiber material and where the pulp entering into a bleaching line is preferably fed continuously through at least one bleaching vessel in the bleaching line, is treated with at least one acid for adjusting the pH to a value below 7, and with a chelating agent, and is subsequently bleached in at least one stage to a brightness exceeding 75% ISO, preferably exceeding 80%, with hydrogen peroxide or the corresponding quantity of another peroxide, employed in a quantity exceeding 5 kg/BDMT, where the peroxide bleaching takes place at elevated temperature and at a pressure in the bleaching vessel which exceeds 2 bar and where the cross-sectional area of the bleaching vessel exceeds 3 m.sup.2 and the area of the metal surface exposed towards the interior of the bleaching vessel is less than 4V m.sup.

Abstract: In a process for the extraction of celluloses from lignocelluloses, the extraction is carried out by means of heating with aqueous acetic acid under pressure and the addition of formic acid, whereby there is obtained a cellulose with a very low residual lignin content, which can be bleached with ozone and peracetic acid to high grades of white, and acetic and formic acid are recovered by means of distillation, so that waste waters do not, therefore, accumulate.

Abstract: A method for the manufacture of non-chlorine bleached pulp, from alkaline digested cellulose pulp, wherein a suspension of the cellulose pulp is subjected to a series to oxygen gas delignification (O), treatment with complexers (Q) and bleaching with non chlorine-containing oxidative bleaching agents (O,P,Z). The various treatment stages interspersed with washing and/or reconcentration of the cellulose pulp in at least one stage, in conjunction with which a suspension liquid is conveyed essentially in strict counter-current, with the result that the pulp manufacturing process is essentially totally closed with regard to the liquid circuit.

Abstract: A process for the delignification and bleaching of chemical pulp utilizes an acid treatment stage aimed at reducing the quantity of hexene uronic acids present in the pulp by at least 30%, and a pH adjustment stage of the pulp aimed at depositing or redepositing ions of alkaline-earth metals on the fibres of the pulp. The process further includes a washing stage of the pulp and a treatment stage of the pulp with an oxidizing agent. A chelating agent is added to the pulp before and/or during the acid treatment stage and/or before or during the pH adjustment stage or between the pH adjustment stage and washing stage.

Abstract: Filtrates from bleach plants for cellulosic (paper) pulp non-chlorine bleaching sequences are treated to minimize the consumption of ozone in ozone bleaching stages. Organic material in the filtrate used in a washer just prior to an ozone stage is oxidized to make the organic material less attractive to the ozone. It may be oxidized by indirectly heating the filtrate, and then reacting it with oxygen gas in a reactor. Alkali may be added to the filtrate in the reactor. Metallic ions are also removed from the system by applying an electrical potential either to the filtrate, an entire washer prior to the ozone stage, or to the pulp line prior to the ozone stage. All of the wash filtrates are treated and recirculated so as not to discharge any wash filtrates into the environment, or so that the only wash filtrate discharged from the washing system of the bleaching plant is a small stream used for smelt dissolution. A typical non-chlorine bleaching sequence utilized may be OAZEZP.

Abstract: A process for modifying, breaking down or bleaching lignin, material containing lignin or like substances uses oxidation catalysts and suitable oxidizing agents wherein these catalysts are used in combination with aliphatic, cycloaliphatic, hetercyclic or aromatic compounds containing NO, NOH or (A).

Abstract: Provided is a process for removing metals from a bleaching plant spent liquor and recovering a chelating agent which includes the steps of: heating a spent liquor containing a chelate comprising metals bound in a chelating agent to a temperature of at least about 140.degree. C.

Abstract: A process of dignifying lignocellulosic pulp with oxygen followed by treatment of the delignified pulp with a chelating agent, followed by washing, followed by treatment with hydrogen peroxide at an alkaline pH in the presence of an alkali metal silicate at a temperature greater than 100.degree. C. and a pressure greater than 1.5 times the saturated vapor pressure.

Abstract: Kraft pulp is bleached to an acceptable brightness (e.g. 86 ISO or more) without using chlorinated organic compounds, yet the strength of the produced pulp remains commercially acceptable. In the manufacture of pulp, the pulp which is cooked and oxygen delignified to a kappa number of 14 or less, and then is bleached with ozone at a medium consistency. After the ozone treatment, heavy metals are removed from the pulp, and then the pulp is led to oxygen and/or peroxide treatment, which is followed by a second ozone bleaching stage. The sequence (ZT) (EOP) (ZP) is preferred.

Abstract: A process for the delignification and bleaching lignocellulosic-containing pulp, in which the pulp is delignified with an organic peracid or salts thereof, treated with a complexing agent, washed and subsequently bleached with a chlorine-free peroxide containing bleaching.

Abstract: Amphoteric derivatives of aliphatic polyamines, such as diethylenetriamine or triethylenetetramine reacted with long chain fatty acids, esters or triglycerides from various natural or synthetic sources are effective in the softening/texture modification of substrates such as paper, textiles, human skin surfaces and hair tresses, as well as in applications for metal working and lubrication. The polyamines are first reacted with fatty acids, esters or triglycerides derived from various animal, vegetable or synthetic sources ranging in molecular distribution from butyric through erucic acids (e.g. milkfat, soy bean oil, rapeseed oil) to form polyamines or imidazolines; they are then further reacted with unsaturated or halogenated carboxylic acids, carboxylated epoxy compounds or acid anhydrides (e.g. acrylic acid, itaconic acid, chloroacetic acid, maleic anhydrides octadecenyl anhydride) to form the various amphoteric structures.

Abstract: A method that solves the problem of suppressing disturbing effects of transition and alkaline earth metal compounds during bleaching of chemically digested lignocellulosic pulp in a sequence with oxygen bleaching prior to oxidative stages with introduction of for instance ozone, superoxides, hydrogen peroxide and peroxy acids. The conditions during the oxygen bleaching are chosen so that the properties of these metal compounds are changed and the compounds removed from the pulp during the oxygen bleaching under such conditions that the attack on the cellulose is small and the fluctuations of the pulp quality due to fluctuating amounts of these metal compounds decrease markedly.

Abstract: Methods for separating metal ions from pulp material are disclosed including treating the pulp with a chelating agent to produce a pulp flow with dissolved metal ions, washing that pulp flow prior to bleaching with hydrogen peroxide or ozone and mixing the washed liquid containing metal ions with another flow of lignocellulose-containing material in order to bind the metal ions to that flow, washing that flow, and subsequently washing that flow at a reduced pH to produce a wash flow containing metal ions.

Abstract: Disclosed are dispersions of fluorescent whitening agents which are suitable for the fluorescent whitening of coating compositions for coating paper or of fibre dispersions (paper pulps) in paper production.

Abstract: A microfibrillated cellulose containing at least around 80% of primary walls and loaded with carboxylic acids, and a method for preparing same, in particular from sugar beet pulp, wherein the pulp is hydrolysed at a moderate temperature of 60-100.degree. C.; at least one extraction of the cellulose material is performed using a base having a concentration of less than 9 wt. %; and the cellulose residue is homogenised by mixing, grinding or any high mechanical shear processing, whereafter the cell suspension is fed through a small-diameter aperture, and the suspension is subjected to a pressure drop of at least 20 MPa and high-speed sheer action followed by a high-speed deceleration impact. The cellulose is remarkable in that a suspension thereof can easily be recreated after it has been dehydrated.

Abstract: A process for producing a thiourea dioxide fluid by mixing thiourea and a peroxide, or thiourea, a peroxide and a reaction catalyst, or thiourea, a peroxide, a reaction catalyst and a chelating agent, in the absence or presence of pulp and a process for bleaching pulp by the use of the thiourea dioxide fluid produced by the above process economically advantageously with a small chemicals loss and by small consumption of energy.

Abstract: A chemimechanical pulp for use in the manufacture of paper or paperboard products where a high drainability, bulky pulp is desired. The pulp has a long fiber content of between 60 and 75%, a fine-material content of at most 14%, a shive content of less than 0.5%, is refined to a freeness of 600 ml CSF at the lowest, and has a tensile index of at least 10 kNm/kg. A method for producing such a pulp comprises: a) impregnating chips with a lignin softening chemical; b) preheating the chips; c) refining the chips to papermaking pulp; wherein the chips are impregnated and heated over a total time period of at most 4 minutes; a) using a hot impregnating liquid having a temperature of at least 130.degree. C.