蒸汽爆破预处理对稻草刨花板性能的影响∗

摘要

Rice straw,whose outer surface was covered with smooth,water-repellent wax layer,has a high con-tent of silica.Conventional urea formaldehyde (UF)cannot be used to make rice straw particleboard.This study adopted steam explosion to pretreat rice straw with temperature being 160 and 170 ℃ and residence time being 2,4,6 min,respectively.Rice straw particleboards were made from steam exploded rice straw with UF.The results showed the steam explosion effectively got rid of the silica and wax layer on the outer surface of rice straw as well as lowered the pH value of rice straw.As intensity of pretreatment increased,the physical and mechanical properties of panel increased.Particleboards made from rice straw pretreated under 160 ℃/6 min, 170 ℃/4 min and 170 ℃/6 min met the strength requirement of GB/T 4897-2003.%稻草 Si O 2含量较高,并且表皮被光滑的斥水性的蜡层所覆盖,无法使用传统的脲醛树脂(UF)制造稻草刨花板.采用蒸汽爆破法预处理稻草,预处理温度分别为160和170℃,时间分别为2,4和6 min.以预处理后的稻草为原料,利用 UF 为胶粘剂制作稻草刨花板.实验结果表明,经过160℃,停留时间为6 min 和170℃,停留时间分别为4与6 min预处理的稻草制备的刨花板的强度性能达到了国标 GB/T 4897-2003的要求.