WPC-LVL共挤出复合材料的抗弯性能

Flexural Performance of Composite Manufactured by Wood Plastic Composites Co-extruded with Laminated Veneer Lumber

通过共挤出技术制备具有核壳结构的共挤出复合材料(CTC).其壳层为木粉/高密度聚乙烯(HDPE)基木塑复合材料(WPC),核层为杨木单板层积材(LVL).通过三点弯曲试验获得CTC和LVL试件的弯曲性能及破坏模式,并进一步研究水煮-冷冻-干燥环境对两者弯曲性能的影响.结果表明:CTC试件相对于LVL试件,其弯曲强度、弹性模量和抗弯刚度分别下降6.6%,12.7%和16.0%;但由于壳层WPC阻止了核层破坏时裂纹的产生和发展,使CTC试件的失效时间延长了44.1%;水煮-冷冻-干燥处理后,CTC试件的弯曲性能下降幅度明显小于LVL试件,这证明壳层WPC对核层LVL起到了很好的保护作用,WPC和LVL通过共挤出技术可达到很好的组合效应.

Co-extrusion composites(CTC)with core-shell structure were prepared by co-extrusion technology with wood/high density polyethylene based(HDPE)composites(WPC)as shell layer and poplar laminated veneer lumber(LVL)as core layer.Both of the CTC and LVL were treated with boiled-frozen-dry environment at one cycle,and the flexural performance and failure mode of CTC and LVL were investigated by three-point bending test.The results show that the bending strength,bending modulus and bending stiffness of CTC decrease by 6.6%,12.7%and 16.0%,respectively,compared with LVL at room temperature.When the core is broken,the failure time increased by 44.1%,because the shell of WPC preventes the crack generation and development.The boiled-frozen-dry treated results indicate that the CTC had better environmental resistance on flexural performance,resulting from the protection of the shell layer.It can be concluded that WPC and LVL have achieved a considerable combination effect by co-extrusion.