Simultaneous chemical and mechanical treatment of pulp fibre and the resulting changes in pulp properties

The chemical and physical properties of a softwood kraft Pulp were measured following bleaching with ozone under acidic medium-consistency conditions in the laboratory. Pulp and handsheet properties were compared with pulp that experienced identical mechanical treatment but had not been bleached. The ozone treated pulp showed a decrease in lignin content, the degree of cellulose polymerization and the absorption coefficient, as expected. The papermaking properties of the bleached pulp were equal to that of the unbleached pulp, although the energy required to beat the Pulp was reduced slightly.