Modified handsheet making procedures for modelling high grammages and minimal drying restraint

摘要

The current Australian and New Zealand Standard Method for producing handsheets describes a process that produces a single weight 60g/m~2 sheet of paper, or by doubling the stock aliquot, a double weight sheet (120g/m~2). This method has proved very useful over many years for the evaluation of pulp resources. However it is unsuitable when trying to mimic real multi-layered paper and linerboard products made from various furnish mixture combinations. Also it uses a full restraint drying techniques and hence does not allow for shrinkage that occurs on drying on commercial papermachine. This paper will describe two modifications to the standard method to produce: 1) Multi-layered handsheets; and 2) Handsheets dried with minimal restraint. The advantages of theses two modifications are that handsheets are produced that can more closely mimic the multi-layer and basis weight structure of commercial papers including varying composition of different furnishes. While shrinkage that occurs when drying on a commercial papermachine is directional, this can not be fully simulated on the British Handsheet Machine. However, with minimal restraint during drying, a much closer behaviour was achieved compared to that achieved following the standard method.