温度对落叶松小径木异型材弦向干缩系数的影响

摘要

By using IF dryer,this paper studied the tangential shrinkage coefficient of small-diameter polygonal cutting of Larix gmelinii Rupr.The results indicated that the tangential shrinkage coefficient showed two kinds of change trend under the same drying temperature.The first trend is that the shrinkage coefficient decreases firstly and then increases from pith to surface;another is that it increases gradually from pith to face.The differences of the trends were dependent on the frequency of tensile and compressive stress in the wood drying process.The shrinkage coefficient of wood was larger at low temperature,and decreased firstly and then increased as drying temperature increased for the same position.There is a better quadratic correlation between the drying temperature and the shrinkage coefficient of different parts in wood.%运用IF干燥机针对落叶松小径木异型材弦向干缩系数进行研究。研究结果表明,在相同的干燥温度下,干缩系数沿径向呈两种变化趋势,一是由髓部向外先减小后增加,二是由髓部向外逐步增加。变化趋势的不同取决于干燥过程中拉应力和压应力出现的频率。同一部位木材的干缩系数呈现低温较大、随干燥温度的增加先减小后增加的趋势;随干燥温度的增加。各部位干缩系数与干燥温度表现为较好的二次相关性。