Relating wood properties to handsheet porosity and mechanical strength

Abstract

During chemical pulping for papermaking, individual fibres in wood are separated by dissolving the lignin layer cementing these together. The mechanical strength of the paper produced is influenced by the extent to which fibres make physical contact in the fibre network, as well as on the extent of hydrogen-bonding between them. Paper mills often experience variation in endproduct quality, and evidence suggests that this is caused by corresponding variation in quality of the raw material entering the mill. Studies characterising the anatomical and chemical properties of the wood prior to pulping and papermaking have been conducted in an attempt to identify the causes underlying of this variation. However, these studies have only partly explained the variability observed, probably because different fibre types respond differently to processing even under identical conditions. The aim of the current study is to investigate the response of fibres from a range of Eucalyptus nitens pulps to mechanical beating (plasticizing) in terms of the paper-forming (porosity) and strength characteristics of hand-sheets produced. The ultimate aim is to develop greater understanding of the pulping process required by wood of varying quality to achieve target end-product quality