GF/PP Mechanical Properties And Optimization Analysis Of Injection Process Parameters

With the development and progress of the society,resin matrix composites are used more and more widely.Because of the outstanding performance advantages of resin matrix composites,it has obvious advantages over traditional materials.Based on the glass fiber reinforced polypropylene(GF/PP)composites,the short glass fiber particles(SFP)and long glass fiber particles(LFP)with different glass fiber(GF)content were used respectively to make the tensile specimens,bending specimens and impact specimens according to the ASTM standard injection molding.Then the specimens were tested and analyzed by tensile,bending and impact tests respectively.According to the experimental results,the mechanical properties of long glass fiber reinforced polypropylene(LGF/PP)were better than that of short glass fiber reinforced polypropylene(SGF/PP)when the content of GF was the same.And when the content of glass fiber was 30%,the comprehensive mechanical properties of the samples were the best.In addition,the causes of surface fiber and internal fiber orientation were analyzed.The interfacial bonding strength between PP and GF was enhanced by using PP-g-MAH,and the surface floats of GF/PP composites were solved.Injection molding is the main forming method of GF/PP composites,so it is very necessary to optimize the injection process parameters of GF/PP composite products and discuss the optimal process parameters suitable for GF/PP composites.In this paper,the response surface design was applied to optimize the injection molding process parameters with Design-Expert software,and then approximate response surface model was established.Based on this model,the Moldflow was used to carry out the simulation experiment to determine the optimal injection parameters combination.After the response surface model was optimized,the maximum residual stress of the product was 53.05MPa and the maximum volumetric shrinkage rate was 3.5022%.As the products belong to the shell products,the appearance quality and the mechanical properties of the products are higher.Thus,the products need further optimization to obtain the best product quality on the basis of the optimal injection parameters combination.After two times optimization of the holding curve,the maximum residual stress value of the product is 52.21 MPa and the maximum volume shrinkage rate is 3.3514%,which further improve the quality of the product.