Unintended features of the injected part may affect the quality of the product. The present study aims to optimize the injection molding parameters and minimize the shrinkage and sink marks for artificial phalanx bone of the index finger via response surface methodology (RSM). The injection molding process was numerically simulated by the software. The combination of the process parameters was designed by Central Composite Design (CCD) in RSM. Three important process parameters were considered, which are melting temperature, cooling time and injection pressure. Meanwhile, two responses (i.e., volumetric shrinkage and sink marks) were considered in the multi-objective optimization. Regression model, ANOVA analysis and perturbation plot analysis were also highlighted in this study. The simulation results revealed two most significant factors towards the responses and the optimum setting of process parameters were recommended to minimize the shrinkage and sink marks of the injected artificial phalanx bone. The optimum injection molding process parameters are 240 °C of melting temperature, 40 s of cooling time and 12 MPa of injection pressure. The optimized results are expected to be used as the reference in the fabrication of the artificial phalanx bone via injection molding.
