思茅松热处理木材的研究

Studies on the heat-treated Pinus kesiya wood

热处理对于提高木材的尺寸稳定性和耐久性、抵抗生物破坏等性能来说是一种非常有效的方法。作者采用油浴法对思茅松木材进行热处理工艺的探讨，分别对热处理木材的失重率、吸湿率、线性胀缩率、以及微观构造等进行了分析，研究结果表明：（1）思茅松热处理材随着处理温度和处理时间的增加，失重率逐渐增加；（2）思茅松热处理材随着处理温度和处理时间的增加，吸湿率逐渐降低；（3）思茅松热处理材随着处理温度和处理时间的增加，线性胀缩率逐渐降低；（4）在微观构造观察方面，由于早材腔大壁薄，材质较松软，经过热处理后早材部分容易引起径向开裂，早材管胞形态的变形程度要比晚材要大，早材轴向管胞壁的弯曲变形较晚材的要严重。随着热处理温度升高，热处理时间的延长，炭化程度越来越严重，为不使木材物理力学以及微观构造方面遭到严重破坏，建议木材热处理温度为160℃、热处理时间为6～12h或木材热处理温度为180℃、热处理时间为6～8h为宜。

Heat treatment is a very effective method for improving the dimensional stability of wood and durability, resistance properties of biological destruction. In this paper, Pinus kesiya heat treatment process has been researched using by the oil bath method, the weight loss rate of the heat treatment of wood, moisture absorption rate, the linear expansion and contraction rates, and micro--structures etc. have respectively been analyzed, the results show that： （1） the rate of weight loss gradually increased with the processing temperature and processing time increasing ; （2） the moisture absorption rate gradually reduced with the processing temperature and processing time increasing; （3） the linear expansion and contraction rate decreased gradually with the processing temperature and processing time increasing; （4） in the micro--structure observation, heat--treated wood easily leaded to radial cracking, the early wood tracheid shape deformed larger than the late wood, the deformation of early axial tracheid wall was more serious than the later. The mainly reason is big timber cavity wall thin and the materials soft. With the heat treatment temperature and heat--treatment time increasind, the degree of carbonization is more and more serious. In order not to wood physical and mechanical as well as the micro--structure was severely damaged, heat treatment temperature of 160 ℃, heat--treatment time was 6-12h or wood heat--treatment temperature is 180 ℃, heat--treatment time 6 -8h are appropriate.