Abstract: Cellulose is oxidized catalytically using a heterocyclic nitroxyl radical as catalyst, main oxidant acting as oxygen source, and an activator of the heterocyclic nitroxyl radical. The oxidation is performed in a reaction medium which is at medium consistency of cellulosic pulp, which is above 6%, more preferably equal to or higher than 8%, and most preferably in the range of 8-12%. The reaction medium is mixed in a reactor through circulation of the reaction medium back to the reactor.

Abstract: In a method for transporting nanofibrillar cellulose in the form of viscous liquid dispersion, the nanofibrillar cellulose is unloaded from a container (3) through a discharge point (3b) which is the lowermost point with respect to the volume of nanofibrillar cellulose in the container at least at the time of unloading. The nanofibrillar cellulose is unloaded and transported to a target location along a pipe (2) using a progressive cavity pump (P2) operating on a positive displacement principle with the suction side of the pump at a distance from the discharge point (3b).

Abstract: In a method for preparing nanofibrillar cellulose, fibrous dispersion of ionically charged cellulose is repeatedly passed through a mechanical process of disrupting fibers into fibrils until the viscosity starts to decrease. The number average diameter of the nanofibrillar cellulose after the mechanical process is in the range of 2-10 nm, and the zero-shear viscosity is below 10 Pa·s, preferably below 1 Pa·s, when measured in the concentration of 0.5 wt-%. The nanofibrillated cellulose is low aspect ratio nanofibrillated cellulose (NFC-L).

Abstract: In a method for manufacturing fibril cellulose, cellulose based fibre raw material is processed mechanically in a refining gap for separating fibrils. The fibres to be refined are subjected to the action of a surface roughness Ra provided by grits elevated from a refining surface delimiting the refining gap, said surface roughness being lower than 3 ?m, advantageously lower than 2 ?m. The refining surface is formed by spraying grits and binder onto a substrate.

Abstract: A method for processing fibril cellulose which is in the form of aqueous fibril cellulose gel includes lowering the pH of the aqueous fibril cellulose gel to provide aqueous fibril cellulose gel of reduced water retention capacity, and dewatering the aqueous fibril cellulose gel of reduced water retention capacity to provide dewatered fibril cellulose. The dewatering is performed by pressure filtration.

Abstract: A method for fibrillation of cellulose includes the following steps: introducing fibre pulp of anionic cellulose at a consistency of 1 to 4% into a homogenizer, and homogenizing fibre pulp in the homogenizer at a pressure of 200 to 1000 bar, advantageously 300 to 650 bar, and by using 2 to 4 passes through for the same fibre pulp under these conditions, and after passes through, taking pulp from the homogenizer, which pulp has been fibrillated by homogenization to a degree than can be expressed as Brookfield viscosity exceeding 10,000 mPa.s (consistency 0.8%, 10 rpm).

Abstract: Described herein is nanocellulose produced by introducing a mixture of cellulose based fiber raw material and water through a refining gap, having a width smaller than 0.1 mm. In the refining gap, the fiber raw material is subjected to processing forces varying in the direction of introducing said mixture, by means of refining zones provided in the gap one after each other in the feeding direction, whereby the refining surfaces differ in surface patterning and/or surface roughness. The mixture of fiber raw material and water is guided past the refining surfaces in the feeding direction to different locations in the refining zone by by-pass channels provided in the stator. The width of the refining gap is maintained by the combined effect of the feeding pressure of the mixture of fiber raw material and water fed into the refining gap and the axial force of the rotor.

Abstract: A Method of pretreating native cellulose pulp in the manufacture of nanofibrillated cellulose, and a nanofibrillated cellulose product obtainable by the method.

Abstract: A method for concentrating fibril cellulose including subjecting aqueous fibril cellulose at a concentration of not higher than 5% to pressure filtration where water is removed from the fibril cellulose by applying pressure to the aqueous fibril cellulose, and continuing the pressure filtration continued to an end point where over 50% of the water initially present is removed from the fibril cellulose. The pressure filtration is performed at a temperature of 30° C. or higher.

Abstract: The invention relates to a method for manufacturing cellulose material, the method comprising introducing cellulose fibers as raw material pulp (1) to a system, adding an alkalizing agent into the system in order to absorb the alkalizing agent into the cellulose fibers (1), adding an anionic agent into the system in order to absorb said agent into the cellulose 2, 2a, 2b fibers (1), feeding the cellulose fibers (1) to a sieve plate press (6), performing a reaction between the cellulose fibers and the anionic agent at least partly in the sieve plate press (6) in order to produce anionized cellulose fibers having a degree of substitution between 0.05 and 0.35, wherein the reaction is performed at least partly at a consistency of at least 50%. In addition, the invention relates to a system for manufacturing cellulose material and to fibril cellulose produced from anionized cellulose fibers.

Abstract: In a method for producing nanofibril cellulose, cellulose based fibre material, in which internal bonds in the cellulose fibre have been weakened by chemical modification, are supplied, for separating fibrils, through several counter-rotating rotors outwards in the radial direction with respect to the rotation axis of the rotors in such a way that the material is repeatedly subjected to shearing and impacting forces by the effect of the blades of the different counter-rotating rotors, whereby it is simultaneously fibrillated.

Abstract: A method for manufacturing cellulosic material includes: introducing cellulose fibers as cellulosic raw material to a system, conveying the cellulose fibers to an extruder comprising a mixing part and/or a refining part, dosing at least one chemical to the system before the extruder and/or in the extruder and performing a reaction between the cellulose fibers and the chemical(s) at least partly in the extruder, wherein the reaction is performed at a consistency of at least 40%, and/or dosing at least one chemical to the system before the extruder and/or in the extruder and mixing the cellulose fibers and the chemical(s) in the mixing part of the extruder, wherein the mixing step is performed at a consistency of at least 40%, and/or refining the introduced cellulose fibers at least partly in the refining part of the extruder, wherein the refining step is performed at a consistency of at least 5%.

Abstract: In a method for catalytic oxidation of cellulose a heterocyclic nitroxyl radical is used as catalyst, hypochlorite is used as main oxidant acting as oxygen source, and a tertiary amine or chlorine dioxide as an activator of the heterocyclic nitroxyl radical.

Abstract: Described herein is nanocellulose produced by introducing a mixture of cellulose based fiber raw material and water through a refining gap, having a width smaller than 0.1 mm. In the refining gap, the fiber raw material is subjected to processing forces varying in the direction of introducing said mixture, by means of refining zones provided in the gap one after each other in the feeding direction, whereby the refining surfaces differ in surface patterning and/or surface roughness. The mixture of fiber raw material and water is guided past the refining surfaces in the feeding direction to different locations in the refining zone by by-pass channels provided in the stator. The width of the refining gap is maintained by the combined effect of the feeding pressure of the mixture of fiber raw material and water fed into the refining gap and the axial force of the rotor.

Abstract: The invention relates to a process for preparing micro- and nanocrystailine cellulose material in the presence of an acid. More specifically, the invention relates to a process, in which the cellulose material is hydrolyzed in the presence of an acid in the gas phase while the moisture content of cellulose is between 1% and 80%, the cellulose material is surface-modified, and mech anically treated in order to obtain micro- and/or nanocrystailine cellulose material. The invention also relates to a cellulose product prepared by the said process and the use thereof in food and liquid crystal applications as well as in optical, cosmetic and medical applications.

Abstract: The invention relates to a method for processing an aqueous gel of nanofibrillar cellulose by removing water from the aqueous gel by means of an organic solvent miscible with water. In the method: aqueous gel is introduced into a volume of organic solvent miscible with water in a controlled manner so that the aqueous gel is kept as a separate phase and forms discrete physical entities containing the nanofibrillar cellulose within the phase; water is changed with the organic solvent in said discrete physical entities of nanofibrillar cellulose; and the physical entities are separated from the volume of organic solvent.

Abstract: A method for manufacturing pulp. The manufactured pulp includes at least 30 w-% nanofibrillated cellulose material measured from the dried pulp. A raw material is introduced to a system. The raw material includes cellulose. At least one type of an optical brightening agent is dosed as a refining additive to the system. The raw material is refined in the presence of the dosed optical brightening agent in at least one pre-refining stage or fibrillation stage to form fibrillar cellulose material.