高温热处理对重组竹物理力学性能的影响

Effects of heat treatment on physical-mechanical properties of reconstituted bamboo lumber (RBL)

在4个不同的温度和时间水平下,对新鲜毛竹竹束进行了高温干燥-热处理,利用冷压热固化方法压制重组竹,研究了热处理温度和时间对重组竹物理力学性能的影响规律。结果表明:经过干燥-热处理后,重组竹的耐水性能有所提高,24 h吸水率(RWA)和吸水厚度膨胀率(RTS)下降幅度分别达6.31%～30.09%和3.96%～40.26%;重组竹的内结合强度(SIB)和静曲强度(SMOR)呈逐渐降低趋势,在本研究范围内,分别降低14.34%～60.96%和21.54%～64.48%。但重组竹的弹性模量(EMOE)与热处理温度的提高和时间的延长没有明显变化。

The experiments of fresh bamboo bundles heat treatment were conducted with four different temperatures and four different duration time,and the reconstituted bamboo lumber（RBL） was made from the bamboo bundles by adopting cold heat-curing method.The effects of treatment temperature and duration time on physical-mechanical properties were investigated.The results show that the heat treatment obviously strengthened the 24 hours water proof property and the water absorption（RWA） rate and thickness swelling rate after water absorption（RTS） declined by 6.31% ~ 30.09% and 3.96% ~ 40.26% respectively,in contrast to the untreated bamboo lumber;and the internal bond strength（SIB） and static bending strength（SMOR） significantly decreased with increasing temperature and duration time;in contrast to the untreated lumber,the heat treatment made the values of SIB and SMOR decreased from 14% to 40% and 22% to 64%,respectively.While the EMOEof RBL didn’t markedly varied as the heat treatment temperature raised and treating time prolonged.