重组竹方材增湿软化工艺

Humidifying and softening processes of recombinant bamboo

针对重组竹方材含水率低、密度大且难刨切的现状,采用不同压力的加压浸注和不同温度的水煮软化工艺对重组竹方材进行增湿软化处理,研究增湿软化后重组竹方材的增重率、传热及硬度的变化情况。研究结果表明:随着压力的增大和时间的延续,重组竹方材的增重率逐步增大,压力1.2 MPa以后增重率增加不明显;随着水煮软化温度的升高和时间的延续,重组竹方材的增重率变化率呈增大的趋势,36.0 h后增大趋势变缓;重组竹内部温度在8.0 h时已趋于稳定。硬度测试结果表明,经过加压浸渍和水煮软化后,重组竹材的硬度下降明显,和未处理材相比下降了36.2%,而重组竹表面的裂纹长度和宽度有所增加,和未处理材相比裂纹平均长度增加了21.1%,平均宽度增加了16.7%。说明采用加压浸注和水煮软化的生产工艺能对重组竹方材起到较好的软化效果,但也在一定程度上影响了其表面的裂纹长度和宽度。

Recombinant bamboo has many good properties, such as nice outlook, fine phisical properties. How- ever, recombinant bamboo has a low moisture content and high density. To determine changes in the weight gain rate and to provide temperature and hardness guidance for humidifying and softening recombinant bamboo, the technique of pressure impregnating and water softening with different pressures and temperatures were conducted. Results showed that with an increase in pressure and time, the weight gain rate increased, but above 1.2 MPa increases in the weight gain rate were not obvious. For the water softening process, with increases of temperature and time, the weight gain rate increased, but slowed after 36.0 h; the internal temperature was sta- ble after 8.0 h. Compared to the control, pressure impregnating and water softening decreased hardness 36.2%. Also, compared to the control group, the crack test showed that crack length increased 21.1% and crack width increased 16.7%. Thus, the manufacturing process had a great positive softening effect on recombinant bamboo, and it had a small nagetive effect on crack length and width with recombinant bamboo surfaces. [ Ch, 4 fig. 2 tab. 16 ref. ]