Validation of an extended objective function for the thermal optimisation of injection moulds

Abstract

The central shaping element in the injection moulding process is the unique injection mould. The tempering channel layout inside the injection mould is the decisive factor in terms of cost-effectiveness and the resulting quality of the moulded parts. The aim of the present research is to further improve thermal mould design by an inverse approach. In the first part of this work, the improvement of the objective function as a central element of the inverse thermal mould design is explained based on theoretical evaluations. The aim of the revised objective function is a homogeneous temperature distribution in the moulded part at the end of the cooling phase and the achievement of a homogeneous morphology in the plastic. The inverse thermal mould design is applied for the first time to a practically relevant moulded part. The usability of the methodology also for complex geometries can be shown. Due to limitations in the choice of materials for additively manufactured injection moulds, conventionally designed cooling systems are usually equivalent in performance. The use of the developed method may reduce the dependence on the experience of the mould designer and results in moulded parts with low distortion.