Effects of wood quality variation in New Zealand radiata pine on kraft paper properties.

Abstract

Variation in wood density, tracheid length, resin content, and incidence of compression wood in radiata pine are documented and discussed with respect to their potential influence on pulp and paper manufacture. In general terms, each of the properties mentioned tends to decrease southwards within New Zealand. Tree average wood density, for instance, drops 20 % from Auckland to Canterbury Conservancies (455 to 380kg/m8). This decrease will result in increased handling costs and wood consumption per tonne of pulp produced, and reduced chemical pulp digester yields. For paper quality, variations in tear index as a consequence of wood property changes are predicted to be substantial. Thus regional wood resource qualities need to be matched with those paper and paperboard products which can be most effectively manufactured from them. Packaging grades of kraft pulps which require high tear strength should, therefore, be produced from the higher density wood found in parts of the Auckland, Rotorua, and Nelson Conservancies.