竹繊維を用いたスタンパブルシートの比曲げ強度および比弾性率のPVA処理による改善

抄録

This study proposes an effective technique to improve the flexural strength and flexural modulus of the stampable sheet fabricated with bamboo fibers. Non-woven cloth fabricated with bamboo fibers and PP (polypropylene) slivers were prepared by conventional carding method. The non-woven cloth was pressed on a heat press machine to make the stampable sheet after soaking in a PVA(Poly Vinyl Alcohol) water solution and then they were dried in an electric oven (PVA treatment). Specific bending strength and specific elastic modulus of the stampable sheets were determined by three point bending tests. The interfacial strength between treated bamboo fiber and PP were also measured by the pull-out test, after the tensile property of treated bamboo fiber was investigated.Results of three point bending tests showed, at first, that 80.1% of improvement in specific strength of was observed, when the stampable sheet was fabricated with the modified bamboo fibers appropriately treated by the PVA solution. It was suggested that the PVA worked as the adhesive between bamboo fibers and PP, in which interfacial failure was prevented by the PVA treatment, while debonding was observed in original stampable sheet with untreated bamboo fibers in this study. By the PVA treatment, 55.6% of improvement in specific flexural modulus of the stampable sheet was also obtained. It was also suggested that the enhancement of flexural modulus was explained by the improvement of observed elastic modulus around the connected bamboo fibers so that elastic deformation of adhesive connections constructing bamboo fibers network was prevented, if the bamboo fibers were treated with PVA solution.