Numerical Simulation of Fiber orientation of Short Fiber Reinforced Polypropylene in Injection Molding

摘要

Based on generalized non-Newtonian fluid with seven parameters Cross-WLF viscosity model and modified 2-double Tait model, the numerical simulation was carried out for the short glass fiber reinforced PP injection molding process of rectangular part. The influence of main process parameters on fiber orientation is investigated. The results show that fiber orientation can be generally divided into three-regional layers in injection molding, that is outer-surface, subsurface and core layer. The degree of fiber orientation in subsurface layer is the highest and that in core layer is the lowest. The influence of fibers interaction coefficient (C_i) and fibers aspect ratio (r_e) on fiber orientation is significant. There is obvious difference between simulation results and practical results without consideration of C_i. The effect of melt temperature, mold temperature and cooling tubes number on fiber orientation isn't obvious.