Mechanical and dimensional characterisation of polypropylene injection moulded parts in epoxy resin/aluminium inserts for rapid tooling

The current paper proposes a new hybrid mould manufactured by casting with epoxy resin and aluminium. After manufacturing, polypropylene parts were injected using the proposed mould. The mechanical properties and dimensional deviation were assessed from the injected parts, in order to evaluate the proposed mould. Besides, comparing with the real application, similar parts were injected using a mould manufactured in AISI P20 steel (ordinary mould). The results show that unless the hardness occurs there is no significant difference between the parts injected using both moulds, in terms of yield strength, maximum strength and Young modulus. The geometric deviation of the parts injected using the mould manufactured with AISI P20 steel showed a bit lower shrinkage compared to those parts injected with the mould manufactured with epoxy/Al. These results show that epoxy/Al moulding blocks can be a high-quality alternative for rapid tooling for manufacturing short series of products.