东北产硬阔叶树小径木干燥工艺的研究

本文主要研究东北产硬阔叶小径材的干燥工艺问题。通过对柞木、水曲柳和桦木板材的常规干燥试验,提出了可行的干燥基准,确定了合理的干燥工艺。试验的板材厚度均取25mm。试验结果表明,在保证干燥质量的前提下,与普通锯材比较,干燥时间大大缩短。测定了三个树种的干缩系数,并和普通锯材作了比较。分析了边材、心材和髓心材的干缩特点,阐明了小径材弦径向干缩差异大是其难干的一个主要原因。另外,髓心对干燥缺陷的产生影响较大。讨论了热湿处理与干燥速度、弦径向干缩比和干燥应力之间的关系。

STUDY ON DRYING TECHNOLOGY OF THINNED HARDWOOD GROWN IN THE NORTHEAST REGION OF CHINA

In this thesis, drying technology of thinned hardwood grown in the northeastern China are discussed and through the experiments conventi- onal drying schedules are used for oak, ash, and birth (all is 25mm in thickness). The results of experiments indicate that the drying time is greatly reduced compared with. that of common timber ia good quality. The shrinkage coefficients of three kinds of wood are compared; with those of common timber. The shrinkage characteristics of sapwood, heartwood and pithwood are discussed, The main reason that thinned timbers are uneasily to be dried is great different in shrinkage between tangential and radial directions. Piths have great effect on drying defects. The effect of hydrothermal treatment on drying rate, ratio of tangential shrinkage to radial shrinkage and drying stress is discussed.