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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。
This paper mainly studies the drying process of hardwood leaves in northeast China. Based on the conventional drying experiments on oak, ash and birch planks, a feasible drying criterion was proposed and a reasonable drying process was determined. The thickness of the test plate are taken 25mm. Test results show that under the premise of ensuring the quality of drying, compared with ordinary sawn timber, drying time is greatly reduced. The dry shrinkage coefficients of three species were measured and compared with those of ordinary sawn timber. The characteristics of stem sapling of sapwood, heartwood and pulpwood were analyzed. It was clarified that the difference of radial shrinkage and shrinkage of sapling was the main reason why it was hard to dry. In addition, the pith has a greater impact on dry defects. The relationship between heat and moisture treatment and drying speed, chord radial shrinkage ratio and drying stress were discussed.