Stereolithography for injection mould tooling

Abstract

Explains that stereolithography (SL) can greatly reduce initial tooling costs, thus making prototyping and small production runs economically feasible. Describes how epoxy resin SL5170 and Zeneca filled resin are used to build SL injection moulding tools. Different sets of tools were evaluated, based on the maximum number of successful injections and quality of performance. A polymer tool requires a minimum level of strength, thermal conductivity and dimensional accuracy. The Zeneca SL tool achieved a total number of 200 successful injections before starting to fail. However, the failure happened during the first shot of the day where the initial injection pressure was set high. On the other hand, epoxy tools were more resistant to injection pressure and temperature and more than 500 injections were achieved without tool failure. In all tests the cavity was never damaged and it was the core which failed during either injection or ejection. Concludes that product diversity, high product complexity, increase in product variety, and shorter product life are prime motives for SL tooling.