速生材木质部构造对浸渍特性的影响

Effects of xylem structure on impregnating preformance

为了探讨速生材浸渍过程,为设计浸渍改性工艺提供依据,作者采用脉冲式加压浸渍方式,将改性剂浸注于欧美杨原木木质部;通过光学显微镜和扫描电子显微镜观察杨木素材和改性材。观察发现杨木导管众多,导管间具有互列纹孔、穿孔板等构造,导管通过木射线联通成大毛细管体系,可在脉冲式压力作为推动力下迅速成为主浸渍渠道;导管、木射线与木纤维细胞间存在纹孔结构,可形成辅流通渠道;EXDA分析显示,浸渍剂可以一定程度上均匀渗透木材微孔。结果表明,速生杨木木质部细胞构造决定了浸渍发生时,杨木可在脉冲压力下迅速浸渍,但在一定时间内,浸渍才能趋于均匀。

In order to understand the impregnating process and provide the basis information for improve- ment of the impregnation technique, the xylem of fast-growing poplar was impregnated with wood modifier in a way of pulse type pressure. Through the optical microscope and electron microscope observation of the dried sample of poplar, we found it had plenty of vessels with alternate pit and perforate structure that formed a capil- lary system through wood rays, which could become primarily impregnating channels with pulse type pressure; and the pits between wood cells could function as auxiliary impregnating channels. Element distribution analysis showed that impregnant could be evenly permeated into the wood micro-space. In conclusion, poplar can be im- pregnated quickly, but some time is needed to dip evenly because of its xylem structure.