平面密度分布对刨花板内结合强度的影响

平面密度变异是非单板类木质人造板所共有的一种结构现象 ,其变异程度和分布特征对板材性能有一定影响。本文利用单板条模拟 4种具有不同平面密度分布的刨花板 ,讨论了随机铺装刨花板坯模型的平面密度分布规律及试件大小与密度分布的关系 ,分析了密度以及平面密度分布对非单板类木质人造板内结合强度的影响。结果表明 :随机铺装刨花板的平面密度遵循正态分布规律 ;内结合强度受密度影响较大 ,密度增加有助于内结合强度提高 ,但密度过高将导致内结合强度下降 ;试件大小影响试件之间密度变异程度 ,适当增加试件尺寸 ,可降低内接合强度测试结果的离散性。

Effects of Horizontal Density Distribution on Internal Bond Strength of Particleboard

Horizontal density variation is a structural phenomenon of non-veneer wood composites. The variation and distribution characteristics of horizontal density have impacts on the products properties. In this study, veneer strip simulated flake boards with four density distribution were made using a mat model. The density variation of the modeled mats was discussed, as well as the relationship between sample size and density variation. The effects of density and density distribution of non veneer composites on the internal bond strength were analyzed. Result shows: the horizontal density of random formed particleboard follows Normal distribution. Density has remarkable influence on internal bond strength (IB). Increasing density helps to improve IB at lower density stage, but has negative impacts on IB at higher density stage. Density variation between testing specimens depends on their sizes. Suitable specimen size increase can decrease the variation of the internal bond strengths.