A Numerical Simulation and Multi-objective Optimization for the Plastic Injection Molding of a Centrifugal Pump Casing

Abstract

Plastic pumps are used to efficiently move liquids within aquaculture systems and seafood processing facilities. Commonly, the centrifugal pump casing is fabricated by plastic injection molding technology. In the plastic injection molding process, the control parameters are essential to the success of plastic molding product fabrication. This study aims to optimize process parameters for the quality of centrifugal pump casing during plastic injection molding using a combination of response surface methodology (RSM) and the NSGA-II method. Firstly, the L27 orthogonal array design of the experiment method is used, which has four input variables, including plastic temperature, mold temperature, cooling time, and injection time (filling time and packing time). The output responses of the injection molding process to be evaluated are the warpage and shrinkage deformation of the molded product. After obtaining data, the RSM model is applied to describe the relationship between the input and output variables. Finally, multi-objective optimization uses the NSGA-II method for the best product quality. The results show that the optimized parameters for injection molding of the centrifugal pump casing are a plastic temperature of 200°C, mold temperature of 65°C, cooling time of 25s, and injection time of 10s with warpage of 0.868 mm, and shrinkage of 10.104mm.