Manufacturing Guidelines for Micro Injection Molds

Abstract

The large demand for micro injected plastic parts can be solved with the reconversion of conventional mold machine shops in order to be suitable for performing micro manufacturing of molds and dies. This paper documents the fabrication of the cavity, ejection, injection and cooling systems of a micro mold for plastic injection in order to ensure a reduction in geometrical variation and to establish guidelines for the conversion of conventional mold shops. As a result, process planning guidelines are presented to reduce the amount of geometrical variation introduced through the main sources: part handling, electric discharge machining and milling operations. Unlike the approach of process planning methodologies available, which are aimed for conventional molds, this study provides guidance for selecting appropriate machine tool equipment for the machining of micro molds. Furthermore, the application of the proposed process planning guidelines seeks to facilitate the incursion of conventional mold shops into the micro mold industry by limiting the dimensional error of micro mold cavities.