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

本研究研究了软木纤维和两种杉木颗粒（刨花和刨花）制成的复合板的机械和物理性能，以开发高性能的木基板。首先，研究了木纤维与两种颗粒的混合比例对均质板性能的影响。均质板的弹性模量随颗粒与纤维混合比的增加而增加，特别是纤维刨花板。纤维板、纤维刨花板、纤维刨花板和混合板的抗弯强度无显著差异。随着混合比的增加，木材的弯曲性能保持率增加。相反，不同板间的内部粘结强度没有一致的差异。以纤维单元为面层，以颗粒单元（剃须或股）为芯层的三层板，其抗弯性能明显高于普通三层板。这是由于热压过程中在表层使用纤维时形成了高密度的表层。其次，在室内自然气候条件下，评估了10种软木纤维和杉木颗粒制成的实验室复合板的弯曲蠕变性能。本试验在每个应力水平下，每个板采用3个重复。应力水平；10、20、30、40%，加载时间；max。290h，考试时间；可能10-Aug。1994年10人。木纤维与颗粒均质板的相对蠕变随颗粒与纤维混合比的增加而增大，特别是纤维支架板的相对蠕变。这是因为具有大接触面积的大薄片在颗粒之间提供了足够的水平剪切强度。以颗粒单元（刨花或刨花）为面层，以纤维单元为芯层的三层板的相对蠕变比中密度纤维板和具有相反单元结构的三层板低得多。这与短期弯曲性能完全相反。在相同材料（50%纤维和50%剃须）制备的3种复合材料板上测试了应力水平对复合材料蠕变行为的影响，结果表明，随着应力水平的增加，表面为纤维的3层复合材料板的相对蠕变增加的趋势比其他两种复合材料板的趋势更明显。相对蠕变与复合材料的弯曲性能比（MOE/MOR）之间的相关性最强。然后根据复合材料的弯曲性能比来估计复合材料的相对蠕变。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