无醛水性热熔胶制备胶合板工艺及性能初探

Preliminary Study on the Technology and Performance of Plywood Prepared by Formaldehyde-free Water-based Hot Melt Adhesive

以桉木单板为原料,以自制的改性水性热熔胶为胶黏剂主剂,以异氰酸酯为交联剂,采用分步试验的方法研究了涂胶量、组坯后闭口陈放时间、板坯预压后至热压前存放时间以及热压工艺对胶合板性能的影响。研究结果表明,采用自制改性水性热熔胶制备胶合板可行;本试验得到的优化工艺为双面涂胶量260 g/m^(2),闭口陈放时间2 h,预压后板柸存放8 h后,热压高压段压力1.6 MPa保持150 s、中压段压力1.3 MPa保持210 s、低压段压力0.3 MPa保持180 s。采用该工艺制得的胶合板物理力学性能达到GB/T 9846—2015《普通胶合板》中I类胶合板要求,甲醛释放量为0.012 mg/m3,达到ENF级要求。

Using eucalyptus veneer as the raw material,self-made modified water-based hot melt adhesive as the main adhesive agent,and isocyanate as the cross-linking agent,a step-by-step experimental method was used to study the effects of the amount of glue spread,the closed storage after assembly,storage time of pre-pressed slabs before hot pressing and hot pressing process on the performance of plywood.The research results showed that it was feasible to use self-made modified water-based hot melt adhesive to prepare plywood.The optimized process obtained was a double-sided adhesive coating of 260 g/m^(2),closed storage time of 2 hours and the storage time of pre-pressed slabs 8 hours.The optimized process obtained was that the pressure and pressing time in the high-pressure section were 1.6 MPa and 150 s,that in the medium-pressure section were 1.3 MPa and 210 s,that in the low-pressure section were 0.3 MPa and 180 s.The physical and mechanical properties of the plywood produced by this process met the requirements of Class I plywood of the standard GB/T 9846—2015 Plywood for general use.The formaldehyde emission amount was 0.012 mg/m3,which met the ENF level requirements of the standard.