THE INFLUENCE OF PULP BEATING AND PAPERMAKING AGENTS ON THE CHARGE DENSITY OF FIBERS AND COLLOIDAL PARTICLES IN PAPERMAKING WATERS
The first part of the paper is focused on monitoring the impact of the beating process on the charge density of fibres and colloidal particles in water in the production of tissue papers. Three types of pulps most commonly used were tested: long-fibre pine pulp, short-fibre eucalyptus pulp and short-fibre hardwood birch pulp. In the range of beating degrees from 14°SR to 35°SR, the impact of beating on the charge density of fibres expressed as Zeta potential, the charge density of colloidal particles expressed as PCD value and the conductivity of the paper suspension were evaluated. The paper also evaluates the impact of beating on the physical and mechanical properties of laboratory sheets. The second part of the paper is focused on monitoring the impact of papermaking aids, in the production of tissue papers, on the charge density of fibres and colloidal particles in water. The most significant impact was demonstrated by the agent for increasing the wet strength of paper. In these laboratory tests, pulp mixtures were used that were prepared by separately beating individual pulps to a beating degree of 25°SR.