Improving Eucalyptus Pulp Refining Through the Control of Pulp Consistency and Stock pH: Comparisons at Given Bulk and Given Tensile Strength, 1999 Papermakers Conference Proceedings

Celso Foelkel

Eucalyptus pulps have short and numerous fibers. They are well-suited to the manufacture of printing & writing and tissue papers. Refining is a vital step in preparing the pulp to papermaking. Refining optimization may improve the eucalyptus pulp performance oriented to the end product. Papermakers are willing to achieve sheet specifications, such as bulk, tensile, tear, porosity, etc.

When optimum refining is searched, the comparisons among treatments may be performed at given bulk or tensile index, instead of given freeness or given net energy. This is a more realistic situation regarding the end product quality.

In this paper, the properties of handsheets were compared at given bulks and given tensile. When the purpose is to improve fiber bonding, mainly to the printing & writing papers, the pH and consistency are suggested to be higher (pH around 9, consistency around 5). Tissue papers require loosen sheet structure. In this case, it is advised to run beating at lower pH’s (5-7) and lower consistencies (3-4%).