单板条层积材(PSL)施胶方法与热压工艺的研究

以杨木碎单板切成的单板条制作PSL为研究对象,通过分析单板条的尺寸形态、施胶的胶液浓度与施胶时间对单板条吸胶量影响,考察了3种不同的施胶方法、热压时间与温度对PSL物理力学性能的影响,优化了热压工艺。结果表明,单板条的尺寸形态对其吸胶量没有显著的影响,它主要影响产品的均一性和外观质量;胶黏剂的浓度是影响单板条吸胶量的一个重要因素,选用胶液浓度为30%的酚醛树脂胶;施胶方法是影响PSL力学性能的重要因素;热压时间和热压温度对PSL的物理力学性能有显著的影响。综合考虑产品的物理力学性能和产品均一性,以单板条长度为100mm,采用喷胶方式,热压时间为35min、热压温度为150℃时制成的PSL的性能较好。

Glue Application and Hot-pressing Technology of Parallel Strand Lumber

Parallel strand lumber(PSL) was manufactured from the waste poplar veneer strips,a by product from plywood enterprises.The influences 3 glue application methods,time of hot pressing and temperature on the physical and mechanical properties of PSL were investigated by analyzing the impacts of size of the strips,glue concentration and application time on the amount of glue-absorbing of each strip.Hot pressing technology was optimized.The results showed that the size of the veneer strands had no notable influence on the glue-absorbing amount,and it mainly affected the homogeneity and appearance quality of the product.The glue concentration is the main factor to affect the glue-absorbing amount of veneer strands,and in this study,PF resin with a concentration of 30% was selected.The glue-applying way was the main factor to affect the mechanical property of PSL.The hot-pressing time and temperature had significant influence on physical and mechanical properties of PSL.Considering physical and mechanical properties and homogeneity of product comprehensively,it was concluded that PSL with satisfactory quality would be manufactured by adopting the following conditions: length of veneer strands: 100 mm,glue application way: spraying;time of hot pressing: 35 min;temperature of hot pressing: 150 ℃.