Structural Composite Boards Made from Wood Fiber and Domestic Plantation Conifer Wood

为开发高性能人造板，研究了软木纤维与两种Sugi碎料(刨花板和刨花板)复合板材的力学和物理性能。均质板的弹性模量随着颗粒与纤维混合比的增加而增大，尤其是在纤维集合板上。然而，纤维板、刨花板、纤维绞合板和混合板的抗弯强度没有显著差异。弯曲性能保持率随木屑混合比的增加而提高。以纤维板为面层，刨花板为芯层的三层板，其弯曲性能明显高于…更多的三层板软管采用逆元件结构。这是由于在面层上使用纤维时，在热压过程中形成了高密度的表面层。其次，在室内自然气候条件下，评估了10种由软木纤维和Sugi颗粒制成的复合板的弯曲蠕变行为。在这项研究中，每个板子的三个重复在每个压力水平上被使用。应力水平为10，20，30，40%，加载时间为10，20，30，40%，试验条件最大为290h，1994年5月10日-8月10日。对于木纤维和碎料制成的均质板材，相对蠕变随着碎石与纤维混合比的增加而增加，尤其是在纤维立板上。这是因为较大的薄片和较大的接触面积为颗粒之间提供了足够的水平剪切强度。以颗粒单元(刨花板或绞线)为面层、纤维单元为芯层的三层板的相对蠕变显著低于MDF和逆单元结构的三层板。至于应力对三种相同材料(50%纤维和50%刨花板)复合板的蠕变行为的影响，随着应力水平的增加，以纤维为表面的三层板的相对蠕变增加的趋势比另外两种BOADS更明显，相对蠕变与受试复合板的弯曲性能比(MOE/MOR)有最强的相关性。然后从复合板的弯曲性能比估计其相对蠕变。较少

This Research deals with the mechanical and physical properties of composite boards made with soft wood fiber and two types of Sugi particle (shaving and strand) in order to develope high performance wood based boards.Firstly, the effect of mixing ratio of wood fiber and two types of particle on the properties of homogeneous boards were evaluated. Modulus of elasticity of homogeneous boards increased with increasing mixing ratio of particle to fiber, especially at fiber-strand boards. However, no significant differences were found among the bending strengths for fiber board, fiber-shaving board, fiber-strand board and the mixed boards. Bending property retention increased with increasing mixing ratio of wood particle. On the contrary, there was no consistent differences in internal bond strength among boads.Three-layr boards that consisted of fiber elements as face layrs and particle elements (shaving or strand) as a core layr showed remarkably higher bending properties compared with t … More hose of the three-layr board hving the inverse element construction. This was due to the formation of high density surface layrs during hot pressing when fiber was used un the face layrs.Next, flexural creep behavior of ten laboratory composite boards made with soft wood fiber and Sugi particles was evaluated under natural interior climate. In this study, three replicates of each board were used at each stress level. Stress level ; 10,20,30,40%, Loading time ; max.290h, Test term ; May 10-Aug.10 in 1994.As for relative creep of homogeneous boards made with wood fiber and particle, relative creep increased with increaing mixing ratio of particle to fiber, and especially at fiber-stand board. This is because large flakes with their large contact areas provide sufficient horizontal shear strength between particles.Three-layr boards consisted of particle elements (shaving or strand) as face layrs and fiber element as a core layr showed remarkably lower relative creep than MDF and the three-layr board having the inverse element construction. This is completely oposite construction to short-term bending property.As for the effect of stress lebel on the creep behavior, which was measured on the three kinds of composite boards made with the same materials (50 percent fiber and 50 percent shaving), the three-layr board made with fiber for the surfaces had a tendency to increase in relative creep more sharply than the other two boads with an increasing stress level.The strongest correlation was observed between the relative creep and the bending properties ratio (MOE/MOR) of tested composite boards. Then it appered to esttimate the relative creep of composite boards from their bending properties ratios. Less