Authors: Ping Xu Huawu Liu Robert Evans Lloyd A Donaldson
Publish Date: 2008/10/11
Volume: 43, Issue: 5-6, Pages: 423-439
Abstract
The behaviour of longitudinal shrinkage was investigated in the corewood of a swept 17yearold New Zealand radiata pine stem Wood categories in terms of normal wood mild compression wood and severe compression wood were identified microscopically using autofluorescence of lignin Average longitudinal shrinkage was collated according to corewood location and wood category within corewood in the leaning and the vertical parts of the stem and then maximum radial difference of longitudinal shrinkage within growth ring was examined The results show that the average longitudinal shrinkage is significant 24 in the corewood of the leaning part of the stem Among wood categories severer compression wood displays the highest 29 average longitudinal shrinkage In the context of this study growth rings may consist of one of three types of wood 1 only normal wood 2 a single compression wood type and 3 mixedtype wood Where multiple compression woods coexisted with normal wood the maximum radial difference of longitudinal shrinkage within the growth ring was found to be 40 A strong correlation R 2 = 090 between average MFA and average longitudinal shrinkage suggests a significant influence of the average MFA on average longitudinal shrinkage across the three growth ring types
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