泡桐木材压缩硬化研究初报──泡桐压缩木回弹率的影响因素

Compressed and Stiffened Paulownia Wood (Ⅰ) The Factors Affecting the Springback Rate of the Compressed and Stiffened Wood

为了提高泡桐的密度、硬度和尺寸稳定性,将试材分成水分组、温度组、时间组、化学处理组，对水分组试材进行恒温恒湿处理，对化学处理组进行不同质量分数的酚醛树脂液浸泡处理，然后将各组试材进行不同温度、不同时间的热压试验．再将试材置于常温的水中浸泡，测定各处理试材的回弹率．分析试材含水率、热压温度、热压时间和酚醛树脂溶液质量分数对热压试材水浸泡回弹率的影响．结果表明；各试验因素对泡桐压密硬化效果有明显的影响，木材含水率为13．89％时．材面光滑，尺寸稳定性最好，热压前的喷湿处理可增强木材尺寸稳定性；用10％的酚醛树脂溶液处理试材可降低回弹率45．51％；最佳热压温度为190℃，最佳热压时间为8min.

In order to enhance the density, hardness and dimension stability of the compressed and stiffened Paulownia wood, this study divides the samples into four groups. They are: water group, temperature group, time group and chemical treating group. The samples of water group were treated under constant temperature and moisture. The samples of chemical treating group were treated by soaking in phenolic resin solution with different concentrations. All samples were hot-pressed under different temperature and time, then were immersed in the normal atmospheric temperature water, and finally, the springback rates of the compressed samples were determined. The studying results show that each of the four factors obviously affected the compressed Paulownia wood on hardness, density and dimension stability. When the moisture content of the samples was 13. 89 %, the surface of the samples were smooth, the dimension stability was the best. Before hot-pressing, spraying water upon the surface of the samples could increase the dimension stability. The springback could be decreased from 90. 96% (untreated wood) to 45. 51% by soaking the samples in 10% phenolic resin solution. The favorable hot-pressing time is 8 minutes at 190℃.