摘要
【目的】研究经高温热处理后速生桉木材物理性能、力学性能的变化，为工业生产提供技术参考。【方法】在水蒸气保护下，经不同温度（160、180、200、220、240℃）、不同时间（1、2、3 h）处理后，按照GB/T 1927~GB/T 1943国家标准检测其物理性能和力学性能。【结果】随着热处理温度提高，速生按木材含水率大幅下降，干缩率、吸水性、湿胀率逐步下降；木材密度随着温度提高和时间延长呈下降趋势；处理时间对顺纹抗压强度、冲击韧性和硬度影响较大；各温度条件下处理1 h的效果最好，抗弯强度在同温度条件下，处理1 h最高，3 h次之，2 h最低；随着热处理温度的升高，弹性模量先增大后减小。【结论】高温热处理对速生桉木材的物理性能影响较大，干缩性、吸水性和吸胀性明显下降，尺寸稳定性上升；速生桉木材的力学性能随着温度的升高和木材热处理时间的延长总体上呈下降趋势。
【Objective】This research studied the changes in physical properties and mechanical properties of fast-growing eucalyptus wood that underwent high temperature heat treatment to provide parameters for industrial production.【Method】Under water vapor protection， wood samples were heat treated at different temperature levels （160， 180， 200， 220， and 230℃） under three different time durations （1， 2， and 3 h）， then the physical and mechanical properties were determined according to GB/T 1927-GB/T 1943 national standards. 【Result】As the temperature of heat treatment increased， the moisture content increased considerably while the dry shrinkage rate， water absorption， and wet expansion rate gradually decreased. The wood density decreased as the temperature increased and treatment time prolonged. Effects of the processing time on the parallel-to-grain compression strength and the impact toughness and hardness were significant. Heat treatment for 1 h was optimal out of all heat treatment conditions. Under the same temperature conditions， the flexural strength was the highest after 1 h of treatment， medium after 3 h of treatment， and lowest after 2 h of treatment. As the heat treatment temperature increased， the elastic modulus first increased then decreased. 【Conclusion】High temperature heat treatment had great effects on the physical properties of eucalyptus wood， in which the dry shrinkage， absorbent condition， and expansion condition obviously decreased and the dimensional stability increased. As the treatment temperature increased and the heat treatment time continued， the mechanical properties of fast-growing eucalyptus wood exhibited an overall declining trend.
出处
《南方农业学报》
CAS
CSCD
北大核心
2013年第1期116-120,共5页
Journal of Southern Agriculture
基金
广西林业科技招标项目(桂林科字[2009]第7号)
广西教育厅科研立项项目(桂教科研[2011]第14号)
关键词
速生桉木材
高温热处理
物理性能
力学性能
fast-growing eucalypt wood
high temperature heat treatment
physical properties
mechanical properties
