In a method for producing nanofibril cellulose, cellulose based fiber material, in which internal bonds in the cellulose fiber 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.

In a method for producing nanofibril cellulose, cellulose based fiber material, in which internal bonds in the cellulose fiber 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.

In a method for producing nanofibrillar cellulose, cellulose based fibre material, in which internal bonds in cellulose fibres have been weakened by 5 preliminary modification of cellulose, is subjected to disintegration treatment in form of pulp comprising fibres and liquid. The fibre material is supplied at a consistency higher than 10 wt-%, preferably at least 15 wt-%, to a disintegration treatment where fibrils are detached from the fibre material by joint effect of repeated impacts to the fibre material by fast moving 10 successive elements and the weakened internal bonds of the cellulose fibres. The nanofibrillar cellulose is withdrawn from the disintegration treatment at dry matter which is equal or higher than the consistency of the fibre material.

In a method for producing nanofibrillar cellulose, cellulose based fibre material, in which internal bonds in cellulose fibres have been weakened by 5 preliminary modification of cellulose, is subjected to disintegration treatment in form of pulp comprising fibres and liquid. The fibre material is supplied at a consistency higher than 10 wt-%, preferably at least 15 wt-%, to a disintegration treatment where fibrils are detached from the fibre material by joint effect of repeated impacts to the fibre material by fast moving 10 successive elements and the weakened internal bonds of the cellulose fibres. The nanofibrillar cellulose is withdrawn from the disintegration treatment at dry matter which is equal or higher than the consistency of the fibre material.

A defibration processing apparatus includes: an input port into which a raw material is input; a rotating body that rotates about a rotary shaft; a stationary member that covers at least part of the rotating body; and a discharge port through which a defibrated object obtained by the rotating body and the stationary member defibrating the raw material is discharged, in which the rotating body has a plurality of rotating blades protruding in a direction away from the rotation center shaft, and the stationary member has a configuration in which a screen having a plurality of openings is disposed in at least part of the stationary member in a direction of the rotation center shaft and surrounds the rotating body in a rotation direction.

In a method for producing nanofibrillar cellulose, cellulose based fibre material, in which internal bonds in cellulose fibres have been weakened by preliminary modification of cellulose, is subjected to disintegration treatment in form of pulp comprising fibres and liquid. The fibre material is supplied at a consistency higher than 10 wt-%, preferably at least 15 wt-%, to a disintegration treatment where fibrils are detached from the fibre material by joint effect of repeated impacts to the fibre material by fast moving successive elements and the weakened internal bonds of the cellulose fibres. The nanofibrillar cellulose is withdrawn from the disintegration treatment at dry matter which is equal or higher than the consistency of the fibre material.

In the disintegration treatment, the fibre material is supplied through several counter-rotating rotors (R1, R2, R3 . . . ) outwards in the radial direction with respect to the rotation axis (RA) of the rotors in such a way that the material is repeatedly subjected to shear and impact forces by the effect of the blades (1) of the different counter-rotating rotors.

In a method for producing nanofibrillar cellulose, cellulose based fibre material, in which internal bonds in cellulose fibres have been weakened by preliminary modification of cellulose, is subjected to disintegration treatment in form of pulp comprising fibres and liquid. The fibre material is supplied at a consistency higher than 10 wt-%, preferably at least 15 wt-%, to a disintegration treatment where fibrils are detached from the fibre material by joint effect of repeated impacts to the fibre material by fast moving successive elements and the weakened internal bonds of the cellulose fibres. The nanofibrillar cellulose is withdrawn from the disintegration treatment at dry matter which is equal or higher than the consistency of the fibre material.

In the disintegration treatment, the fibre material is supplied through several counter-rotating rotors (R1, R2, R3 . . . ) outwards in the radial direction with respect to the rotation axis (RA) of the rotors in such a way that the material is repeatedly subjected to shear and impact forces by the effect of the blades (1) of the different counter-rotating rotors.

In a method for producing nanofibrillar cellulose, cellulose based fibre material, in which internal bonds in cellulose fibres have been weakened by preliminary modification of cellulose, is subjected to disintegration treatment in form of pulp comprising fibres and liquid. The fibre material is supplied at a consistency higher than 10 wt-%, preferably at least 15 wt-%, to a disintegration treatment where fibrils are detached from the fibre material by joint effect of repeated impacts to the fibre material by fast moving successive elements and the weakened internal bonds of the cellulose fibres. The nanofibrillar cellulose is withdrawn from the disintegration treatment at dry matter which is equal or higher than the consistency of the fibre material. In the disintegration treatment, the fibre material is supplied through several counter-rotating rotors (R1, R2, R3 . . . ) outwards in the radial direction with respect to the rotation axis (RA) of the rotors in such a way that the material is repeatedly subjected to shear and impact forces by the effect of the blades (1) of the different counter-rotating rotors.

In a method for producing nanofibrillar cellulose, cellulose based fibre material, in which internal bonds in cellulose fibres have been weakened by preliminary modification of cellulose, is subjected to disintegration treatment in form of pulp comprising fibres and liquid. The fibre material is supplied at a consistency higher than 10 wt-%, preferably at least 15 wt-%, to a disintegration treatment where fibrils are detached from the fibre material by joint effect of repeated impacts to the fibre material by fast moving successive elements and the weakened internal bonds of the cellulose fibres. The nanofibrillar cellulose is withdrawn from the disintegration treatment at dry matter which is equal or higher than the consistency of the fibre material. In the disintegration treatment, the fibre material is supplied through several counter-rotating rotors (R1, R2, R3 . . . ) outwards in the radial direction with respect to the rotation axis (RA) of the rotors in such a way that the material is repeatedly subjected to shear and impact forces by the effect of the blades (1) of the different counter-rotating rotors.

A method is provided for processing wood fibers comprising providing a refiner comprising a first refining member including first refiner bars and a second refining member including second refiner bars. The first refining member may be spaced from the second refining member to define a refining space therebetween. The first and second refiner bars may be separated by refiner grooves. The method further involves rotating at least one of the first refining member or the second refining member, and supplying a slurry of wood pulp comprising wood fibers to the refiner such that the wood pulp slurry passes through the refining space. The one refining member is rotated at a power level sufficient to create a refining intensity within the refining space of at least about 3 Newtons.