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

关键词:  共挤出复合材料  核壳结构  弯曲性能  破坏模式  壳层保护

Key words:  co extrusion composite（CTC）  core shell structure  flexural performance  failure mode  shell protection

摘要:

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.

Abstract:

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.