摘要
对大断面欧洲赤松(Pinus sylvestris)进行真空变定/真空高频干燥及高温变定/高温干燥,对比研究木材表面变定对干燥材含水率分布、颜色变化及开裂的影响。结果表明:与高温变定/高温干燥相比,真空变定/真空高频干燥后木材含水率在长度及厚度方向分布均匀,但厚度方向上与高温干燥相反,呈现心层低、表层高的趋势。总处理时间基本一致,但高频真空干燥时间比高温干燥少9 h,干燥速度更快。高温干燥的L*、a*、b*及ΔE*的变化幅度分别是高频真空干燥的2.9、1.8、3.0及2.9倍,高频真空干燥后木材变色小,干燥后表面开裂宽度及长度比均小于高温干燥。干燥后木材含水率及开裂符合GB/T 6491—2012Ⅲ级室外建筑用材标准,对大断面木材做真空变定/真空高频干燥是一种更为优良的干燥方法。
Scots pine ( Pinus sylvestris)with large cross sections were dried using radiofrequency / vacuum and high temperatureafter vacuum setting and high temperature setting respectively. Compared with high temperature setting,the moisture content distribution along fiber and cross section after vacuum settingdrying was even,while that was low in the central location and high in the outer location at the cross section. The total treatment time was almost same,but radiofrequency / vacuum drying was faster as much as 9 h. The discoloration parameter of L*,a*,b*and ΔE* were 2.9,1.8,3.0 and 2.9times to radiofrequency / vacuum. The surface crack situation was smaller than high temperature drying. The moisture content distribution and cracks met the national standard GB/ T6491-2012Ⅲ,and the vacuum setting with radiofrequency /vacuum drying was a practical drying method for large dimension timbers.
出处
《东北林业大学学报》
CAS
CSCD
北大核心
2017年第2期61-64,共4页
Journal of Northeast Forestry University
基金
国家自然科学基金项目(31570558
31500479)
中国博士后基金面上项目(2015M581805)
江苏高校优势学科建设工程资助项目(PAPD)
青蓝工程资助
关键词
真空变定
高频真空干燥
大断面木材
干燥质量
Vacuum drying set
Radiofrequency / vacuum drying
Large cross section timber
Drying quality