注塑条件对长玻璃纤维/聚丙烯材料拉伸性能的影响

Effect of Injection Moulding Condition on Tensile Strength of Long Glass Fiber Reiforced PP

利用自行研制的玻纤增强聚丙烯预浸装置制备了长玻纤增强聚丙 (LGFRP)粒料 ,并利用普通注塑机成型了长玻纤增强聚丙烯试样。研究了模具和注塑工艺对注塑试样拉伸强度的影响。实验发现 ,对注塑成型的平板试样 ,其拉伸强度具有位置分布 ,边缘处的拉伸强度高于中间部位。对哑铃形试样 ,所用模具的浇口尺寸越大 ,试样的拉伸强度就越高。注塑温度 (从 2 0 0℃～ 2 5 0℃ )对注塑试样的拉伸强度影响较小。较低速度注塑试样的拉伸强度要高于高速注塑试样。

Using an impregnation/pultrusion device developed at our laboratory,long glass fiber reinforced polypropylene(LGFRP)pellets were produced.Test bars were injection molded by a conventional injection machine.Effects of injection moulds and injection parameters on tensile strength were studied.For the molded plate samples a position dependent tensile strength was found.The tensile strength at the plate edge was found higher than that at the plate middle.For the molded dumb samples,tensile strength increased with the runner size,and decreased with the injection speed both monotonously.The injection temperature had less effect on the tensile strength in the range from 200℃ to 250℃.