Fibre damage in unbleached reinforcement pulp - The effect of hemicelluloses and lignin on the susceptibility of fibres to damage during oxygen delignification

摘要

The targeted modification of hemicellulosic components and lignin was carried out using specific enzymes in order to study the role of these components in the susceptibility of fibres to damage during oxygen delignification. The results showed that: The removal of xylan, which combined with lignin serves the purpose of stress-equalizing matrix, leads to brighter pulp with lower kappa, but simultaneously to increased susceptibility of fibres to deform, with higher resistance to straightening during PFI refining. The removal of glucomannan, which is more associated with cellulose, affected mainly wet fibre strength measured as wet zero span, and less tear-tensile strength properties and fibre form than xylan. The removal of lignin resulted in improved pulp strength properties compared to reference samples. Based on these results, it can be suggested that the level of fibre damage in oxygen delignification is determined to some extent during the kraft pulping.