摘要
桉木的含水率、密度及干缩率等物性参数对桉木的干燥及改性极其重要。为研究试验过程取样对上述参数测量的影响,随机选用两块尾巨桉(Eucalyptus urophylla×E.grandis)试件进行浸水、气干及绝干试验,测量不同阶段试件的含水率、密度及干缩率,并进行对比分析。结果表明:随机取样对木材的初含水率、饱水含水率的测量影响非常显著,两组试件初含水率测量值最大相差66%,而对气干含水率测量影响较小,测量值差异小于2%;随机取样对基本、气干、绝干密度的测量影响显著,两组试件的测量值分别相差15.3%、12.5%、16%,而对饱水密度的测量影响较小,测量值相差约1.8%;随机取样对木材干缩率影响较小,径向、弦向气干缩率差异在1.1%以内,体积干缩率差异在1.58以内,而对绝干干缩率的测量影响略大。
The physical parameters of eucalyptus such as moisture content,density and dry shrinkage rate are very important for the drying and modification of eucalyptus.In order to study the influence of sampling during the test on the measurement of the above parameters,two specimens of Eucalyptus urophylla×E.grandis were randomly selected for water immersion,air drying and absolute drying tests,with the moisture content,density and dry shrinkage rate of the specimens at different stages measured and a comparative analysis made.The results showed that random sampling had a significant impact on the measurement of the initial moisture content and saturated moisture content of the wood,with the maximum difference between the two groups of specimens'initial moisture content measurement being 66%,while the air-dry moisture content measurement suffered little influence,with the measured value difference of less than 2%;random sampling had a significant effect on the measurement of basic,air-dry,and absolute dry densities.The measured values of the two groups of specimens differed by 15.3%,12.5%,and 16%respectively,while the measurement of saturated water density suffered little influence,with measured value difference of about 1.8%;random sampling had little effect on the wood shrinkage rate,with the radial and chord air shrinkage rate difference within 1.1%,the volume shrinkage rate difference within 1.58,while the absolute dry shrinkage rate measurement suffered slightly greater influence.
作者
李芝兰
杨琳
LI Zhi-lan;YANG Lin(College of Furnishings and Industrial Design,Nanjing Forestry University,Nanjing Jiangsu 210037,China)
出处
《林业机械与木工设备》
2021年第8期57-61,66,共6页
Forestry Machinery & Woodworking Equipment
关键词
随机选样
尾巨桉
含水率
密度
干缩率
random sample selection
Eucalyptus urophylla
moisture content
density
dry shrinkage rate
