2025 Volume 79 Issue 2 Pages 154-162
In Indonesian pulp and paper manufacturing, Acacia and Eucalyptus spp., particularly A. crassicarpa and E. grandis×pellita hybrid woods are used as materials. This study compares fiber characteristics, pulp properties, and bleachability of the two species. The possible advantages of fractionation and laccase treatment for the acacia and eucalyptus kraft pulps were investigated. The fiber morphology of acacia pulp showed that longer fiber length, thinner cell wall thickness, lower kink, higher fines and smaller fiber population, resulting higher sheet strength properties than that of eucalyptus pulp. Comparing between the fractions, the short-fiber fraction contained more fibrillated fibers and the sheet strength increased. The total chlorine dioxide consumption in ECF bleaching was 23.3 kg/adt for acacia pulp. That of eucalyptus pulp was 15.5 kg/adt, and the bleachability was better than that of acacia. The difference in bleachability is thought to be due to the differences in the pulp brightness and the structure of residual lignin. Laccase treatment of pulp prior to ECF bleaching reduced the total chlorine dioxide consumption, especially in the medium and short fiber fractions.
