摘要
为探究最佳的巨尾桉汽蒸预处理工艺,分别采用80℃、100℃、120℃对20 mm厚的含水率分别为130%、60%、50%、30%、20%的巨尾桉试件进行汽蒸处理。以汽蒸后可见缺陷为主要评价指标,结合扫描电镜进行微观结构分析,并对其汽蒸前后的含水率、抽提物含量、干燥后可见缺陷进行比较分析。结果表明:巨尾桉气干含水率和汽蒸温度分别为50%,100℃时汽蒸效果最佳,汽蒸后可见缺陷最少,能有效防止后续干燥过程中干燥缺陷的产生;汽蒸后桉木的部分纹孔膜破裂,导管内壁光滑,水分移动通道畅通;热水、1%Na OH和苯醇抽提物含量减少,有利于渗透性的提高。
To explore the most suitable steaming process,Eucalyptus grandis X E.urophylla boards with thickness of 20 mm,whose moisture content of 130%,60%,50%,30%,20%were steamed at 80℃、100℃、120℃respectively.Visible defects were investigated,combining with scanning electron microscope to analyze the micro structure before and after steaming.Changes of moisture content,the extractives content and defects developing during kiln-drying were considered.Results showed that the steaming effects were satisfactory when the MC was 50%and temperature was 100℃,respectively.The degree of visible defects of samples steamed in this condition was slighter than other groups,effectively avoiding subsequent drying defects developing.Some of the pit membranes in samples were broken up and ducts were smooth,contributing to improving the permeability.There was a slight reduction of hot water,1%NaOH and benzene-alcohol extractives after steaming,which provided evidence that duct was clear and the permeability was improved.
作者
孔璐璐
赵紫剑
何正斌
伊松林
Kong Lulu;Zhao Zijian;He Zhengbin;Yi Songlin(Beijing Key Laboratory of Wood Science and Engineering,MOE Key Laboratory of Wooden Material Science and Application,Beijing Forestiy University,Beijing 100083,China)
出处
《西南林业大学学报（自然科学）》
CAS
北大核心
2018年第2期158-164,共7页
Journal of Southwest Forestry University：Natural Sciences
基金
林业公益性行业科研专项经费(201404502)资助。
关键词
巨尾桉
气干
汽蒸
干燥缺陷
渗透性
Eucalyptus grandis×E.urophylla
air-dry
steaming
drying defects
permeability
