The application of surface visibility and moldability to parting line generation

Abstract

In molding, casting or forging processes, part surfaces are formed by the core, cavity and local tools in molding/casting or by the upper and lower dies and local tools in forging. In computer-aided design of dies and molds, automatic identification of surfaces molded/formed by these different tooling components is critical since the generation of parting lines depends on these surfaces, which would further influence the determination of parting surfaces, the creation of core and cavity blocks and the entire mold structure. In this paper, the surface partability and visibility are first proposed and its moldability is next presented. Considering the molding process as an instance, the concepts of core-, cavity- and the local tool-molded surfaces are defined. A methodology based on surface visibility and moldability to determine the potentially and actually moldable surfaces of these groups is developed. Since the generation of parting lines is a crucial preliminary design step in mold/die design life cycle, a new approach to determining the parting lines based on the proposed methodology is presented. A case study is used to test the methodology and approach, and to validate the efficiency in parting line generation of molded parts. © 2002 Elsevier Science Ltd. All rights reserved.