摘要
试样（２×２×５ｃｍ）在温度１２０℃和１００℃两种饱和水蒸汽条件下分别汽蒸处理８小时，然后置于大气中干燥至含水率为１０％左右时，采用水上升置换气流法进行渗透性测定。汽蒸试样的渗透性分别与其纵向相邻接的未汽蒸、含水率约１０％的对照比较，并进行成对比较分析ｔ检验。试验结果表明，各树种的木材性质不同，汽蒸作用引起木材解剖上、化学上的变化也不同，因而汽蒸处理对木材渗透性的影响各异。红松气干边材、心材经１２０℃和１００℃汽蒸处理后渗透性分别较未汽蒸者提高约６０、９０％和４０、１３０％；长白鱼鳞云杉生材边材经１２０℃汽蒸后和气干心材经１００℃汽蒸后渗透性分别较未汽蒸者约提高３２６和８０％；成对比较分析ｔ检验，汽蒸试样与未汽蒸试样渗透性之间差异可靠性为９０－９９．９％；汽蒸试样渗透性获得提高的原因均系汽蒸后纹孔膜和纹孔塞发生开裂的结果。但汽蒸长白鱼鳞云杉生材心材、气干边材和心材及臭冷杉生材心材、气干边材和心材的渗透性则未获得提高。
The effect of steaming on the permeability of spruce (Picea jezoensis var. komarovii), fir (Abies nephrolepis) and pine (Pines koraiensis) woods were studied. The green and air-dried specimens (2 ×2 ×5cm) for treatment were steamed at 120℃(1kg/cm2) and 100℃ (1kg/cm2) for 8 hours under water vapor saturated conditions and then subjected to air-drying untill about 10% moisture content. A rising-water volume-displacement method was used to measure air permeability in the longitudinal direction of the wood. The gas permeabilities of the steamed specimens were compared with those of matched unsteamed controls (m. c. ≈10%). The result showed that the effect of steaming on the permeability of wood is variable due to that the change of wood structure and chemical composition caused by steaming is not the same in different wood species with different properties. The average permeability of steamed at 120℃ and 100℃ air-dried pine sapwood and heartwood was increased by approximately 60%, 90% and 40%, 130%respectively. The average permeability of steamed at 120℃ green sprucesapwood and steamed at 100℃ air-dried spruce heartwood were increased by approximately 326% and 80%. The increase in permeability of steamed wood was attributed to produce crack in pit membrane and torus after steaming.Paired comparison analyses (t) were carried out between the steamed and the matched unsteamed specimens. Significant was at the 90-99.9% level.However, steam treatment had no effect on the permeability of steamed green spruce heartwood, air-dried sapwood and heartwood, as well as steamed green fir heartwood, air-dried sapwood and heartwood.
出处
《林业科学》
CAS
CSCD
北大核心
1994年第4期352-357,T003,共7页
Scientia Silvae Sinicae
基金
国家自然科学基金
关键词
渗透性
汽蒸
纹孔膜
木材
Permeability, Steaming, Pit membrane
