Relations Between Permeability and Structure of Wood

The permeability and the structure of heartwood and sapwood of the solvent-exchange dried and the air-dried greenwood of Chinese-fir (Cunninghamia lanceolata (Lamb.) Hook.) and masson pine (Pinus massoniana Lamb.) were measured in order to study the relations between the permeability and the structure. The results showed that the permeability of sapwood of both the air-dried and the solvent-exchange dried wood was higher than that of heartwood, and the permeability of the solvent-exchanged dried heartwood and sapwood was higher than that of the air-dried. A higher permeability of wood was attributed to, on the one hand, a bigger number of flow path per unit area of the wood perpendicular to the flow direction resulted from a bigger number of unaspirated pits per unit area and a bigger number of effective pit openings per membrane, and on the other hand, a smaller number of tracheid in series connection per unit length parallel to flow direction resulted from a longer tracheid length and an effective tracheid length for permeability.

杉木和马尾松木材渗透性与微细结构的关系研究

对杉木和马尾松心材与边材、溶剂置换干燥木材与普通气干木材的纵向气体渗透性与微细结构进行测定 ,来研究它们的渗透性与微细结构的关系 .结果表明 ,杉木和马尾松边材渗透性比心材高 ,与前者的纹孔膜有效流体渗透微孔数比后者多、管胞长度比后者长、管胞搭接率比后者低、管胞流体有效渗透长度比后者长有关 .溶剂置换干燥木材渗透性高于普通气干木材 ,是因为前者纹孔闭塞率低 ,每个管胞开放纹孔数、单位面积开放纹孔数、纹孔膜有效流体渗透微孔数比后者多 .