Multidisciplinary robust and reliability-based design optimization of injection molding system

Even a slight reduction in production cost can make a huge impact in a mass manufacturing domain like injection molding. In this paper, we proposed design modifications to the conventional multi-cavity injection mold insert for the reduction of overall mold material costs required for molding a part family. Additionally, the reduced size of the proposed insert makes it more suitable to manufacture it using metal additive manufacturing and exploit the associated benefits. We also provided formulations to minimize cycle time and pressure drop of the melt simultaneously in the modified design using integrated multi-objective optimization and multidisciplinary design optimization framework. The proposed flexible multi-cavity-inserts are designed to mold multiple part family members whose geometric dimensions are allowed to vary within a permissible limit. Hence, there exists uncertainty in the input variables. Two approaches: robustness-based design optimization and reliability-based design optimization are used to handle the uncertainty in the input variables. A case study is presented to numerically illustrate the implementation of the proposed optimization frameworks. Our formulations provide Pareto optimal design options for the flexible multi-cavity-insert that will open opportunities to produce small plastic parts having dimensional similarity economically.