摘要
薄型单板层积材（LVL）可替代锯材,应用于木质门窗构件等轻载结构领域。由于单板全部顺纹组坯,导致产品存在横向翘曲变形的技术问题。为此,尝试采用＂部分单板横纹组坯＂和＂纤维板与单板复合＂两种方法进行改进,制造了15 mm厚LVL,包含1~2层单板横纹组坯或1~2层3 mm纤维板。测试结果表明：单板横纹组坯,显著降低了LVL的抗弯性能,但LVL的弹性模量仍能达到单板层积材国家标准中70E级别的要求,而静曲强度甚至超过180E级别优等品的限值;与此同时,改进结构的LVL吸水翘曲变形显著降低。横纹单板越靠近LVL表层,板子抗弯性能降低越显著,而翘曲变形改善越明显。采用纤维板与单板复合制造LVL,纤维板的内结合强度衰减明显,易受破坏。
Thin LVLs can substitute for lumbers in light-load applications such as wood door or window parts.However,it＇s pliable to transversely warp since all veneers are laid in longitudinal direction.Two improving methods,i.e.,to lay up partial veneers vertically or to replace partial veneers with thin fiberboards,were tried in this study.Quantitatively,1 or 2 layers of veneers with transverse direction or fiberboards of 3 mm thickness were combined into 15mm thick LVLs.Properties testing results showed that：（1） LVLs with veneers laid up perpendicularly all satisfied LVL national standard（GB/T20241—2006） in MOE of 70E grade and in MOR better than even 180E grade,although the bending properties decreased significantly compared with the control boards;and the warping of LVLs resulted from moisture absorption was obviously controlled.The closer the two veneers were placed to LVL surface,the more significantly MOR/MOE and warping decrease.（2） The fiberboards combined in LVL showed evidently lower inner bond（IB） strength and were pliable to be broken,and hence were advised to be eliminated from LVL.
出处
《林业科技开发》
2010年第6期86-89,共4页
China Forestry Science and Technology
基金
江苏省2008年度苏北科技计划项目"意杨层积结构材工艺与装备研究及产业化开发"(编号:BC2008076)
关键词
单板层积材
翘曲变形
纤维板
laminated veneer lumber（LVL）
warping
fiberboard
作者简介
徐信武（1975-），男，副教授，主要从事速生材改性和结构型木质复合材料领域的研究。E-mail：xuearpenter@yahoo．com．cn
