CO_2超临界流体萃取干燥对气凝胶型木材尺寸稳定性的影响

Effects of CO_2 Supercritical Fluid Extractive Drying on Wood' s Dimensional Stability

采用CO2超临界流体干燥技术处理山黄麻木材,研究干燥技术对木材尺寸稳定性的影响。结果表明,超临界CO2流体干燥基本可以保持木材原有的尺寸和形状,且干燥后没有变形、变色等干燥缺陷产生;各因素对试验结果的影响顺序为超临界温度>超临界干燥时间>超临界压强,超临界温度对试验结果的影响显著,木材端面积变化率随着超临界温度的增加而减小;山黄麻木材最优干燥技术为,超临界温度60℃,超临界压强12 MPa,超临界干燥时间3 h。

CO2 supercritical fluid drying technique was proposed on Trema （Trema orientalis） to study the effect of drying technology on wood dimensional stability, the results showed that wood treated by CO2 supercritical fluid drying could basically maintain the original dimension and figure, without deformation, discoloration and crack. On the test, the sequence of every factor for wood from high to low was supercritical temperature, supercritical drying time and super- critical pressure. The influence of supercritical temperature was significant. The change rate of the terminal area was reduced as the temperature increasing. For Trema wood drying, the optimal drying technology were the the following combination： supercritical temperature 60℃, supercritical pressure 12 MPa and supercritical dying time 3 h.