Method for producing nanofibrillar cellulose
AssigneeUpm-Kymmene Corporation
InventorsJuha Tamper, Markus Nuopponen
Life of this patent
Estimating the term…
Abstract
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.
Claims17
A method for producing nanofibril cellulose, wherein cellulose based fibre material, in which internal bonds in the cellulose fibre have been weakened by chemical modification, are introduced in a refining gap for separating fibrils, wherein the fibre material is supplied 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 shear and impact forces by the effect of the blades of the different counter-rotating rotors, whereby it is simultaneously fibrillated, wherein the fibrillation is effected by means of impact energy utilizing a series of frequently repeated impacts having varying directions of action caused by several successive impacts from opposite directions, when the fibre material in suspension is repeatedly impacted by the blades of the rotors striking it from opposite directions when the blades rotate in opposite directions at a rotating speed and at a peripheral speed determined by the distance to the rotation axis of the rotors.
Dependencies are inferred from the claim text.