桉树无性系大径材干燥特性分析

文章编号：2095-1191（2017）05-0896-05

Drying characteristics of Eucalyptus clones with large-diameter

LIU Yuan， LU Cui-xiang， HUANG Teng-hua， CHEN Jian-bo， XIANG Dong-yun

（Guangxi Forestry Research Institute / Guangxi Key Laboratory of Superior Timber Trees Resource Cultivation / Key Laboratory of Central South Fast-growing Timber Cultivation of Forestry Ministry of China， Nanning 530002，China）

Abstract：【Objective】In the present paper， drying characteristics of Eucalyptus clones with large-diameter were studied， and the drying schedule was predicted， in order to provide scientific basis for the utilization of Eucalyptus big-diameter wood. 【Method】Drying characteristics of 10-year-old Eucalyptus clones with large-diameter were studied by 100℃ test method. On the basis of drying defects， namely initial crack， internal crack and cross-section deformation during wood drying process， the drying schedule of Eucalyptus big-diameter wood was proposed. 【Result】The initial crack was grade 2； internal crack degree was moderate， being grade 3； degree of cross-section deformation was serious， being grade 4. Drying speed was grade 4， which meant the drying speed was slow and Eucalyptus a the wood dried slowly. Volume dry shrinkage rate（19.656%）， radial dry shrinkage rate（10.976%） and tangential dry shrinkage rate（9.451%） were large； difference dry shrinkage（0.861） was small. According to the grades of the three defects， the basic conditions of drying schedule were as follows： under the condition of initial temperature 50 ℃， difference between wet and dry bulb temperatures at initial period 2-4 ℃， temperature at late drying period 75 ℃， it took 20.75 d to dry Eucalyptus clones with large-diameter with 25-30 mm thickness to 10.00% moisture content. 【Conclusion】The main defect is section deformation. In order to avoid it， the drying schedule should be initial temperature 50 ℃， difference between wet and dry bulb temperatures at initial period 2-4 ℃， temperature at late drying period 75 ℃ in actual production. This schedule can be adjusted based on specific condition.