Effect of Packing Pressure on Fiber Orientation in Injection Molding of Fiber-Reinforced Thermoplastics

摘要

Injection molding of fiber-reinforced polymeric composites is increasing with demands of geometrically complex products possessing superior mechanical properties of high specific strength,high specific stiffness,and high impact resistance.Complex state of fiber orientation exists in injection molding of short fiber reinforced polymers.The orientation of fibers vary significantly across the thickness of injection-molded part and can become a key feature of the finished product.Improving the mechanical properties of molded parts by managing the orientation of fibers during the process of injection molding is the basic motivation of this study.As a first step in this direction,the present results reveal the importance of packing pressure in orienting the fibers.In this study,the effects of pressure distribution and viscosity of a compressible polymeric composite melt on the state of fiber orientation after complete filling of a cavity is considered experimentally and compared with the simulation results of Moldflow analysis.