Thermal–structural analysis of bi-metallic conformal cooling for injection moulds

Abstract

In injection moulding process, cooling time greatly affects the total cycle time. As thermal conductivity is one of the main factors for conductive heat transfer in cooling phase of IMP, a cooling channel made by higher thermal conductive material will allow faster extraction of heat from the molten plastic materials, thus resulting in shorter cycle time and higher productivity. The main objective of this paper is to investigate bi-metallic conformal cooling channel design with high thermal conductive copper tube insert for injection moulds. Thermal–structural finite element analysis has been carried out with ANSYS workbench simulation software for a mould with bi-metallic conformal cooling channels and the performance is compared with a mould with conventional straight cooling channels for an industrial plastic part. Experimental verification has been carried out for the two moulds using two different types of plastics, polypropylene (PP) and acrylonitrile butadiene styrene, in a mini injection moulding machine. Simulation and experimental results show that bi-metallic conformal cooling channel design gives better cycle time, which ultimately increases production rate as well as fatigue life of the mould.