Study On Injection Molding Process Of Resin-based Glass Fiber Composites

Resin-based glass fiber composites are an excellent lightweight material.It has good dimensional accuracy,good heat resistance and excellent insulation properties,so it is widely used as a molding material for automotive parts and precision parts.Resin-based chopped glass fiber composites can meet our lightweight and performance requirements to a large extent,but how to effectively control the fiber orientation,to optimize the fiber distribution in the product,to obtain better performance products,has become a new challenge.Therefore,based on the traditional injection molding process,this paper proposes a dynamic injection molding process to optimize the fiber orientation during the molding process,in order to obtain better performance products.This paper proposes a new production process,and has done a lot of research in process design,mold design,process optimization and experimental verification.The specific research done in this thesis is as follows:(1)According to the characteristics of resin-based chopped glass fiber composites,in order to optimize the orientation and distribution of glass fibers in products,this paper proposes a dynamic injection molding process,and describes the basic principles and processes of dynamic injection molding processes.Based on the molding principle,this paper designs the dynamic injection mold based on the movable core,analyzes the design points and working process of the dynamic injection mold,and cleverly designs the activity that can expand the cavity while the mold remains closed.The core mechanism makes the overall structure of the mold more compact and simple.(2)After completing the process design and mold design of dynamic injection molding,this paper uses Moldflow software to simulate the forming process of 16 different process parameters,and obtains two quality index results of fiber orientation tensor and warpage.The orthogonal test method was used to analyze the simulation results.The results show that the initial cavity thickness has a significant effect on the fiber distribution.The injection time has a significant effect on the warpage of the product,and the optimal process parameter setting is obtained.The correctness of the dynamic injection molding process and the mold was verified.(3)Based on the analysis of CAE software,this paper carries out production experiments on the test pieces,and introduces and analyzes the problems that need attention in the production process.After the injection of the test piece,the tensile test,bending test and cross-sectional observation of the test piece were carried out.The influence of various parameters on the mechanical properties of the plastic part under the dynamic injection molding process was summarized.It was found that after the dynamic injection molding process was optimized,the product was obtained.The internal structure is more uniform,the tensile strength of the test piece is improved,but the bending strength is slightly improved.