Studies of the Properties of Unbleached Sulphite Pulp with Reference to Their Influence on the Rosin Sizing of Paper

摘要

A study was made of the qualities of sulphite pulp which influence its ability to be sized with fully saponified rosin size and aluminum sulphate. The findings indicated that the sizeability was diminished with decreasing extractives content, but that the distribution of extractives in the pulp was also of importance. Metal ions adsorbed on to pulp improved its sizeability, as did an increase in carbonyl groups and in lignin. It was found that the sizeability was impaired by carboxyl groups. A diminution of the hemicellulose content by alkali extraction increased the sizeability. The fine fraction of a pulp was found to have a greater affinity for rosin size than had the coarse; in all probability this was dependent upon greater specific surface and higher electrokinetic potential. In a study of 32 laboratory cooked pulps, it was found that the lignin content is the pulp factor of major importance to sizeability; a similar result was arrived at in a study of 14 technically cooked, unbleached sulphite pulps. (Author)