Effects of pre-treatment with commercial cellulase and hemicellulase and laboratory beating of unbleached pine kraft pulp on freeness, paper strength, and fiber quality

The effects of laboratory beating on unbleached regular grade pine kraft pulp (UPKP), pre-treated with commercial cellulase/hemicellulase enzymatic preparation (C/HEP) were assessed using degrees of Schopper-Riegler (°SR) and fibre-quality numbers (FQN). The tests showed a significant increase in the °SR (used in papermaking laboratories and industry to assess the degree of beating) of the UPKP after its enzymatic pre-treatment in the amount of 0.25 to 5.0 mL/kg of pulp and beating. However, only a several percent reduction of beating time was observed when the effect of this pretreatment of pulp on the speed of its beating was determined using another method. The treatment of the pulp selected for research with C/HEP before beating negatively influenced its strength properties after this process. The results correlated well with the most important basic fiber properties from the standpoint of papermaking.