刘建霞　王喜明　慕厚春　吴向文

(内蒙古农业大学，呼和浩特，010018)



木材干缩力平衡测试系统的研制1)

刘建霞王喜明慕厚春吴向文

(内蒙古农业大学，呼和浩特，010018)

为了同步测试木材在干燥过程中的干缩力、质量变化和干缩量，研制了木材干缩力测试系统。系统利用了木材干燥过程中水分散失导致外部干缩力变化的关系，设计了基于温湿度试验箱的一体化控温控湿力学测试系统，更好地研究和探索了木材在干燥过程中的干缩力、质量变化和干缩量之间的关系。测试结果表明：用此设备可实时检测干缩力、质量变化和干缩量的平衡情况，初步调控了木材干缩不均导致干燥过程中的开裂、翘曲变形等缺陷。

木材；干缩力；干缩量；力学测试系统

The integrated mechanics testing system was developed to synchronously determine the stress and shrinkage of drying, and the quality changes of specimens during the drying process. The system was reconstructed from the temperature and humidity chamber, and developed in view of the relation of the overall drying stress and moisture loss in the process of drying. The new testing system was benefit to explore the relationship between drying stress, drying shrinkage and quality changes. By testing, the system could measure the drying stress, shrinkage and quality changes synchronously, and regulate and control the drying defects including checks and warps deformation by the shrinkage heterogeneity.

木材干缩直接影响木材的干燥质量，木材在干燥过程中因水分散失发生尺寸上的减小而产生干缩力。木材在干燥的过程中，表层的水分首先蒸发，当其质量变化降至纤维饱和点以下时，表层开始产生收缩；而相邻内层的质量仍高于纤维饱和点未收缩。在干燥前期，外层受拉应力，内层受压应力；随着干燥的进行，外层逐渐由受拉应力变为受压应力，而内层则变为受拉应力。这种应力直接导致初期端裂、表裂和后期内裂，影响木材和木制品的尺寸、形状和结构的稳定性[1-4]。因此，准确、快速、智能地测量干燥过程中木材的干缩对于提高木材科研水平和木材干燥生产质量、效率具有重要意义。了解木材的干缩力与质量变化、干缩量之间的关系，对研究木材干燥工艺、木材的合理加工和利用意义重大。……