连续玻璃纤维/聚丙烯热塑性复合材料拉挤成型中的工艺参数

采用复合纱拉挤方法制备连续玻璃纤维/聚丙烯(GF/PP)热塑性复合材料，研究了复合纱拉挤成型过程中模具温度及拉挤速度对GF/PP复合材料截面中心温度的影响。以傅里叶定律为理论基础，分析了拉挤过程中模腔内的瞬态传热过程；建立了工艺参数矩阵，通过有限元数值计算，预测了不同模具温度、拉挤速度下GF/PP复合材料截面中心的温度变化，优选了工艺参数组合。通过实验制备不同温度、不同拉挤速度的GF/PP复合材料，并进行弯曲模量测试及截面形貌观察。结果表明:在GF/PP复合纱拉挤过程中，拉挤速度不宜超过350 mm/min，模具熔融区温度设定应高于180℃；GF/PP复合材料在150℃-230℃-50℃成型温度、100 mm/min拉挤速度的工艺参数设定下获得最优的制品力学性能；在设定拉挤参数时，拉挤速度相较于熔融区温度更重要。 

Parameters in process of pultrusion of continuous glass fiber/polypropylene thermoplastic composites

The continuous glass fiber/polypropylene (GF/PP) composites were prepared by thermoplastic pultrusion using GF/PP commingled yarns. The effect of mold temperature and pulling speed on the centraline temperature of GF/PP composites was studied. Based on Fourier law, the transient heat transfer within mold cavity in pultrusion process was analyzed. The process parameter matrix was established. The centraline temperature variation of GF/PP composites under the conditions of different mold temperatures and pulling speeds was predicted using finite element numerical calculation. The combination of process parameter for certain mold structure was optimized. The flexural modulus of PP/GF composites obtained at different temperatures and pulling speeds was tested and the sections were observed. The results show that the pultrusion speed should not exceed 350 mm/min, while the mold melt zone temperature should be set higher than 180℃ in the pultrusion process of GF/PP commingled yarns; the optimized process parameter for best mechanical properties of GF/PP composites is obtained at 150℃-230℃-50℃ temperature and 100 mm/min pulling speed. The pultrusion speed is more important than the mold melt zone temperature in pultrusion process of GF/PP commingled yarns.