摘要
对马尾松锯材热压干燥工艺进行试验研究,结果表明,规格为300mm×100mm×22mm的马尾松锯材的最佳热压干燥工艺为:汽蒸处理3h,压板温度为180℃,压板压力为0.2MPa,呼吸间隔为60s。在此条件下,马尾松锯材含水率从80％降至8％仅需22min左右,而影响其干燥速度的主要因素是压板温度,其次是汽蒸处理时间,压板压力影响最小。经热压干燥的马尾松锯材,表面密度均比内部密度大,最大值增加了8.2％。硬度比气干材增加了789～2849N,为气干材的1.3～2倍。厚度收缩系数为0.291％～0.428％,比气干材的值大0.246％;而宽度的收缩系数为0.113％～0.245％。比气干材的干缩系数小。除材色略有加深外,未出现其它明显的干燥缺陷。
Experiment on the platen drying process of P. Massoniana lumber is made. The results show that ①The optimum technique for press drying the 300 mm× 100mm×22mm lumber of P. Massoniana is as follows: steaming time 3h,platen temperature 180°C , platen pressure 0.2MPa and respiration interval 60s. ② Under above-mentioned condition, the time for the moisture content to drop from 80% to 8% is only about 22 minutes. ③The platen temperature is the first factor affecting the drying rate, the steaming time is the second and the effect of the platen pressure and the respiration interval are slight. ④After being platen dried,surface density of the lumber is higher than internal density and the maximum increase extent get to 8.2 % , ⑤Hardness of the dried lumber is higher than that of air-seasoned lumber by 789-2 849N, the former is about 1.3-2.0 times of the latter. ⑥Thick shrinkage of the dried lumber (0.291%-0.428%)is bigger than that of air-seasoned lumber and width shrinkage of the dried lumber(0.113%-0.245 % ) is smaller than that of air-seasoned one. ⑦Except for surface stain,no other drying defects are observed.
出处
《林产工业》
北大核心
2002年第6期16-19,共4页
China Forest Products Industry
