Plastic Product Evaluation Based on Mold Conceptual Design

Abstract

Severe competition in plastic product manufacturing industry is driving the product design toward first-part-correct. Up to now, plastic product design is mainly evaluated by computer-aided-engineering packages to justify the plastic moulding processes including flow, packing and cooling. At the same time, product designers rely on their experience to justify the possibility of forming products, including parting/de-moulding direction and layout design, as there is rarely practical solution on those perspectives. This paper proposes a methodology to evaluate plastic product design based on downstream mould conceptual design probability. Several aspects of the conceptual mould design, from parting direction, undercut, draft angle to overall layout are studied. A novel undercut detection algorithm which extends the Z-Map to two sets of faces and sub-cells is proposed, and a hybrid parting direction detection mechanism is worked out. A prototype system is developed to help product designers to evaluate their designs based on the mould conceptual design perspectives. The system is tested with dozens of industrial parts and results show that the system can help the plastic part and mould designers to evaluate the designs before they are finalized.