高温饱和蒸汽软化毛竹展平板的平衡含水率和尺寸稳定性

Equilibrium Moisture Content and Dimensional Stability of Flattened Bamboo Softened by High Temperature Saturated Steam

为毛竹展平板干燥终含水率的确定,养生、平衡、仓储环境参数设定等提供理论依据,对两种不同温度高温饱和蒸汽软化毛竹展平板的解吸、吸湿平衡含水率和体积干缩、湿胀率进行测定,研究结果表明:(1)在高温饱和蒸汽软化和展平的共同作用下,毛竹展平板的解吸和吸湿平衡含水率均明显低于同等环境下的木材平衡含水率,160℃和180℃高温蒸汽软化展平板的干燥终含水率为同环境状态时木材平衡含水率的65.17%和62.40%为宜,在通风良好的条件下材料养生、平衡时间250-350h为宜;(2)180℃软化展平板的吸湿和解吸平衡含水率均低于160℃的,软化温度越高,吸湿和解吸平衡含水率越低;(3)180℃软化展平板的体积干缩率和湿胀率均低于160℃的,较高的软化温度有利于提高展平板的尺寸稳定性。

In order to explore the water content,maintenance and balancing,and storage of flattened bamboo for the purpose of theoretical guidance to manufacture,the equilibrium moisture content in the absorption and desorption process of flattened bamboo softened by saturated steam at different temperature,and their volume shrinkage and expansion rates have been investigated.The results showed that(1)with the coordination effect of high temperature saturated steam softening and flattening influence,the equilibrium moisture content in the absorption and desorption process of flattened bamboo were significantly lower than that of wood counterparts under the same conditions.The optimal equilibrium moisture content of flattened bamboo softened at 160℃and 180℃was 65.17%and 62.40%,respectively,when in good ventilated condition,the appropriate time for curing and maintenance of bamboo material was set at 250-350 h;(2)equilibrium moisture content in the absorption and desorption process of bamboo flattening at 180℃was higher than that at 160℃,the higher softening temperature,the lower equilibrium moisture content in the absorption and desorption process of the flattened bamboo;(3)volume shrinkage and expansion rates of flattened bamboo softened by saturated steam at 180℃were lower than that of softened at 160℃,which demonstrated that high softening temperature contribute to the better dimensional stability.