HIGH ASPECT RATIO CELLULOSE NANOFILAMENTS AND METHOD FOR THEIR PRODUCTION

摘要

A novel method is disclosed to produce on a commercial scale, high aspect ratio cellulose nanofilaments (CNF) from natural lignocellulosic fibers. The method consists of a multi-pass high consistency refining (HCR) of chemical or mechanical fibers using specific combinations of refining intensity and specific energy. The CNF produced by this invention represents a mixture of fine filaments with widths in the submicron and lengths from tens of micrometers to few millimeters. The resultant product is made of a population of free filaments and filaments bound to the fiber core from which they were produced. The proportion of free and bound filaments is governed in large part by total specific energy applied to the pulp in the refiner. These CNF products differ from other cellulose fibrillar materials by their higher aspect ratio and the preserved degree of polymerization (DP) of cellulose. The CNF products made by this invention are excellent additives for the reinforcement of paper, tissue, paperboard and packaging products, plastic composite materials and coating formulations. They display exceptional strengthening power for never-dried paper webs.