Characterisation of Beating Through Study of the Visco-Elastic Properties of Paper

Abstract

A strong sulphite pulp was beaten in different laboratory beaters to a series of freenesses. Handsheets were formed according to the British standard method. In this method, the sheets are clamped during drying and, thus, shrinkage in the plane of the paper is prevented. Stress/strain curves were recorded using the apparatus developed by the Steenberg group.

It was found that sheets from pulp beaten to different freenesses in one and the same beater yielded stress/strain curves of approximately the same shape within the range of freenesses examined (Canadian standard freeness 600 250 ml). The shape of the curves, however, differed from one type of beater to another.