The influence of paper mass composition on effectiveness of applying synthetic fillers

Abstract

Efficiency of application of synthetic filler (barium sulfite, having an average particle size of 1.05–1.27 μ ) increases the management of structure of the sized filled pulp. Reducing the particle size from 1.0−5.0 to 1.05−1.27 μ increases the degree of filler retention in the paper structure and, therefore, increases the ash content of the paper and decreases twice the content of suspended solids in the water sub grid. It is possible to explain by the filling process in the geteroadagulation mode. The preferred pulp composition is set to obtain paper with high indices (ash content, brightness, absorbency at unilat-eral wetting, breaking length). The pulp should be obtained in the following manner. For maximum preservation of the mechanical strength of the fibers it is advisable to sequentially introduce into the fibrous pulp slurry barium hydroxide at defibering stage (dispersion process), and sodium sulfite at the grinding stage (the process of internal and external fibrillation). The components are taken in stoichio-metric ratio to obtain a finely divided filler in amount 10% a. d. s.; then aluminum sulfate (0.8% of the flow rate a. d. s.) is added and synthetic sizing agent based on dimers of alkyl ketenes AKD (0.4% of the flow rate a. d. s.), to provide absorbency index under one-sided wetting no more than 20 g/m{2}.