Injection Molding Process Design And Mold Development For Plastic Blocking Sand Bend

Blocking sand bend is the key part of the recycled water storage device.The traditional blocking sand bend is made of cast iron,which has defects of heavy weight, low dimensional accuracy, and easy to jam and rust.The performance of plastic parts is stable, and it’s not easy to produce physical and chemical reactions in the water, which can satisfy the requirement of the performance and service life of the block. But, the traditional method of "try and error correction" of researching and developing blocking sand bend has high cost, and is over-reliance on experience, wasting of resources, and long development cycles.In this paper, injection molding process and injection mold structure are studied by CAD and CAE of injection molding, which aims to satisfy the quality requirement and reduce the deformation.In this paper, the sand blocking pipe structure and selected materials were based on the structure and material of the plastic blocking sand bend,3D model and finite element model had been designed. The injection molding simulation analysis of hot runner gating system and cold runner injection gating system were done respectively, and the hot runner gating system had been designed.To reduce the deformation of the plastic blocking sand bend, three different forms of cooling system had been designed in this paper, and by comparing the simulation results of deformation, the cooling system scheme with minimum deformation was determined.In this paper, the orthogonal test method using Moldflow software DOE analysis module to calculate the various process parameters and their interaction effect on the deformation obtained in a given range of parameters of deformation of minimizing the amount of process parameter scheme:the dwell time is 30s, the cooling time is 100s, the holding pressure equals to 108% injection pressure, and the injection time is 2.0s and the melt temperature is 247.5℃.Based on the design of gating system and cooling system obtained in the simulation analysis, the blocking sand bend had been designed, made and assembled; Trial manufacturewas carried out with the process parameter scheme obtained in the simulation analysis, and the samples formed burr, according to the cause analysis, the melt temperature parameter was reduced to 243℃, then trial again. Finally, the size and quality of the samples was both satisfing the product requirements.In this paper, the plastic product development process by CAD and CAE of injection molding is reasonable and universal, it can provide some reference in development process of other plastic products. and the research results have a direct guidance in the practical production, and the engineering application value is obvious.