Injection mold performance of machined ceramic filled epoxy tooling boards

The RP4037™ tooling board system is a ceramic (silicon carbide) filled epoxy casting system intended for prototype molds in plastic injection molding applications. As with most cast products, machining is necessary due to the fact that cast parts can only be made to near net-shape. However, there is little information available on the performance of machined tooling board systems in injection molding applications. In this study, six molds, made from three different levels of silicon carbide (SiC) filler concentration and machined at two cutting speeds, were used to produce plastic parts. Each of the molds successfully produced 150 parts without any obvious damage or catastrophic failure of the mold. The surface roughness of the molded parts was observed to increase with filler concentration. The flexural strength of the molded parts also increased with SiC concentration. Possible explanations for the observed trends are given.