森林与环境学报2018，Vol.38Issue(3)：277-283,7.DOI:10.13324/j.cnki.jfcf.2018.03.004
尾巨桉木材冷冻干燥特性
Freeze-drying properties of Eucalyptus urophylla×E.grandis wood
摘要
Abstract
Eucalyptus urophylla×E.grandis samples were dried by freeze-drying(FD)(-50 ℃)and conventional kiln drying(CKD)(60 ℃,66％)respectively,the shrinkage curve was measured by scanner and ImageJ software,layered moisture content distribution was measured,collapse and recovery were mirror observed by SEM,and then the drying rate,moisture content(MC)distribution,shrinkage in area and the morphological feature of collapsed cells were compared and the effects of FD on the collapse was investigated as well.The results indicated that the curve of moisture-time of FD was similar with that of CKD,drying rate was fast above fiber saturated point(FSP)and became slow below FSP.Moisture migration channels were created and maintained during FD process and these new channels resulted in high drying rate at about FSP level.In the early stage of FD,the MC distribution was quite different from surface to middle and core layer and with great MC gradient compared with that of CKD.Below FSP,MC distribution of FD became even and the MC distribution was same with that of CKD.The total shrinkage rate of FD was smaller than that of CKD and which is affected by sample length.The quantity and extent of collapsed cells in FD were smaller than that of CKD through SEM observations.Freeze-drying could not avoid the collapse entirely,but it could maintain the shape of cells and decrease the cell collapse significantly.关键词
冷冻干燥/木材皱缩/干燥特性/尾巨桉Key words
freeze-drying/wood collapse/drying properties/Eucalyptus urophylla×E.grandis分类
农业科技引用本文复制引用
杨琳,马青原,刘洪海,廖晓梅,吴智慧..尾巨桉木材冷冻干燥特性[J].森林与环境学报,2018,38(3):277-283,7.基金项目
国家自然科学基金青年项目(31500479) （31500479）
国家自然科学基金面上项目(31570558) （31570558）
南京林业大学高层次人才科研启动基金项目(GXL010) （GXL010）
青蓝工程资助项目(164104841) （164104841）
南京林业大学大学生创新训练计划项目"冷冻干燥对桉树木材细胞形态的影响机制研究" (2017NFUSPITP333). （2017NFUSPITP333）
