パルプの紙層形成能力 第１報 繊維間結合の定量的評価法

Abstract

A quantitative evaluation method of the bonding ability of pulp fibers was developed. In order to prepare a paper-cellophane two layered sheet, a wet web and a wet cellophane sheet were pressed together and dried under restrained condition. The bonded area and bond strength between the paper layer and the cellphane sheet were measured. The ability of pulp fibers to form fiber-to-fiber bonded area was evaluated by the percentage of the paper-cellophane bonded area to all cellophane surface. The ability of pulp fibers to develop bond strength was evaluated by the paper-cellophane Z-tensile strength per paper-cellophane unit bonded area.Using this method, the bonding ability of three different bleached hardwood kraft pulps were investigated on the effect of beating conditions. The results showed that the paper-cellophane bonded area was greatly affected by the fiber cross-sectional shape and was increased by progressive beating. The percentage of the paper-cellophane bonded area to all cellophane surface was found to express the conformability of pulp fibers. This value was defined “conformability index”.On the other hand, paper-cellophane unit bond strength was increased by beating and reached to the maximum values at around 400ml CSF. This value was defined “bond strength index”.