This paper presents the optimisation of the injection moulding process on a pipe fitting using the Taguchi method. This study optimises the injection moulding parameters that yield minimum sink marks and volumetric shrinkage in the injected pipe fitting. Five parameters: cooling time, melting temperature, packing time, packing pressure, and injection pressure, were considered in the simulation. Taguchi method with L27 Orthogonal array was employed to construct the Design of Experiment (DOE) for the simulation analysis. The main responses are sink marks and volumetric shrinkage. The main effect and ANOVA analysis were also studied. The results revealed that melting temperature was the most significant factor influencing sink mark response. However, packing pressure crucially affects the volumetric shrinkage of the injected pipe fitting part. The optimal injection moulding process can be achieved with a cooling time of 26.52 s, a melt temperature of 218 ℃, an injection pressure of 36.23 MPa, a packing pressure of 60 MPa and a packing time of 5 s.
