Pulp and Fibre surface properties of bleached hardwood kraft: pulps - The Influence of an a-stage

摘要

Hexenuronic acids in kraft pulps increase the demand for bleaching chemicals and cause brightness reversion of the bleached pulps during storage. They can, however, be removed by the use of hot acid treatments in e.g. the bleaching sequence, which is commonly used for eucalyptus in the pulp industry today. In this work three kraft hardwood pulps (two eucalyptus and one birch) were selected to study the influence on the surface properties of the pulps of a hot acidic stage (A stage) introduced prior to a standard ECF bleaching sequence. The sequences compared were A/D(EP)DD and D(EP)DD. The results were compared before and after the pulps were aged at room temperature for about eight months.