摘要
为探讨预热处理对尾巨桉木材干缩性和材色的影响,分别在100℃饱和蒸汽和120℃过热蒸汽条件下对尾巨桉木材进行预热处理。对预热处理前后的尾巨桉木材进行干缩率及色度指数的测定,应用扫描电镜对预热处理后尾巨桉木材的微观构造进行分析。结果表明:1)100℃饱和蒸汽可以使尾巨桉的干缩性降低,材色无明显变化;120℃过热蒸汽处理使尾巨桉在干燥过程中出现较多缺陷,如皱缩、内裂等,但可以有效促使桉木颜色向珍贵树种颜色转变。2)经120℃过热蒸汽处理,尾巨桉木材导管中纹孔的内含物被部分排出,细胞被压扁,宏观尺寸发生变形,是导致尾巨桉出现干燥缺陷的主要原因。
To investigate the effects of pre-heat treatment on the shrinkage properties and discoloration of Eucalyptus grandis×E.urophylla wood,the wood samples were pre-heated at 100 ℃saturated steam and 120℃ overheated steam,respectively.The shrinkage ratio and color of the samples after pre-heat treatment were evaluated.The microscopic structure of the samples were analyzed using SEM.The results showed that：1）the shrinkage ratio of Eucalyptus wood samples decreased after 100℃ saturated steam heat treatment,while no obvious discoloration was observed.However,excessive defects appeared during the wood drying process when the samples were subjected to pre-heat treatment under 120℃ overheated steam.Positive color changes could be observed after the wood samples pre-heated under 120℃ overheat steam.2）Parts of the extractives of Eucalyptus were removed by pre-heat treatment,which led to discoloration of the wood samples.The cells were crushed,which resulted in the macroscopic dimension deformation and wood defects during the drying process.
出处
《西北林学院学报》
CSCD
北大核心
2014年第5期176-180,206,共6页
Journal of Northwest Forestry University
基金
国家自然科学基金项目"木材热诱发变色过程中发色体系形成的化学机理"(31070490)
关键词
预热处理
桉木
干缩率
颜色
材性改良
pre-heat treatment
Eucalyptus urophydis
shrinkage
color
wood property improving
