The effect of cellulose degradation on the strength of wood pulp fibres

The relationship between fibre strength loss and cellulose degree of polymerization (D.P.) was examined for different pulps and chemical treatments in an effort to understand the cause of fibre strength loss a high -cellulose contents. Is was found that the decrease in fibre strength is caused by the degradation of cellulose. The nature of the degradation process controls the extent of the strength loss. Homogeneous and random degradation causes little strength loss, but localized degradation weakens fibres significantly. The intermediate stages of acid sulphite cooking, the final stages of kraft cooking combined with mechanical damage, treatments with cellulase enzymes or with liquid-phase hydrochloric acid all cause localized degradation resulting in a significant weakening of fibres.