Design and wrapage analysis of plastic injection mould

This paper presents the design of a plastic injection mould for producing ejector component and performing wrapage analysis for the moulded component. The technique, theory, methods as well as consideration needed in designing of plastic injection mould are presented. Design of mould was carried out using design software and wrapage analysis is done in simulation software. The results show that shrinkage is likely to occur in the region near the cooling channels as compared to other regions. This uneven cooling effect at different regions of mould contributed to wrapage. During cooling, location near the cooling channel experiences more cooling than location far away from the cooling channel. This different temperature causes the material to experience differential shrinkage causing thermal stresses. Significant thermal stress can cause warpage problem. Therefore, it is important to simulate the wrapage analysis of the injection-molded part during the cooling stage. By understanding the characteristics of wrapage, deformation caused can be predicted.