连续纤维增强聚丙烯微发泡注塑过程数值模拟

Numerical Simulation of Microcellular Injection Molding of Continuous Fiber Reinforced Polypropylene Composite Foam

嵌件式微发泡注射成型工艺对改善微发泡制品的力学性能具有重要作用,是实现高强低质制品加工的重要途径之一。通过对连续纤维增强聚丙烯复合泡沫材料嵌件式微发泡注射成型过程进行数值模拟与仿真分析,研究不同进料方式对注射充填过程和制品成型精度的影响。结果表明,与平行于纤维布方向进料相比,垂直于纤维布方向进料不利于熔体的流动与充填过程,并且会造成更大的制品翘曲变形与体积收缩;而与无纤维布嵌件的泡沫制品相比,有纤维布嵌件的泡沫制品的发泡过程更彻底,泡孔尺寸和泡孔密度更均匀,但是会产生较大的热应力,造成更严重的翘曲变形和体积收缩。

Insert-microcellular injection molding was significant for enhancing mechanical properties of lightweight products,which could also solve the issues of preparing high strength and low density products.The numerical simulation for insert-microcellular injection molding of continuous fiber reinforced polypropylene composite foams was carried out,and the influences of different injection ways on filling process and product accuracy were analyzed.Comparedwith injecting parallel to the fiber cloth,injecting perpendicular to the fiber cloth was not conducive to the flowing and filling of melt and led to larger warpage and volume shrinkage of products.Meanwhile,compared with neat polypropylene foams,the foaming process of the continuous fiber reinforced polypropylene foams was more adequate,and the cell size and cell density were more homogeneous.However,it caused greater thermal stress,then resulting in greater warpage and volume shrinkage.