Multi-piece mould design based on a mixed-integer programming method

Abstract

Multi-piece mould design is a moulding technology that involves three-dimensional spatial construction of two or more mould pieces in a manner similar to assembling/dissembling a three-dimensional puzzle to build production parts. Using such a moulding technology, complex parts with intricate geometries can be made for limited run productions. Compared to traditional two-piece moulds and rapid prototyping, the multi-piece mould approach has many advantages with respect to part complexity and production speed, etc.; however, the technology has challenges in designing the actual multi-piece moulds. Previous methodologies address this problem primarily using heuristics. We present a multi-piece mould design (MPMD) framework that is based on a mixed-integer programming approach. The method constructs the MPMD by minimising the number of mould pieces that is required for a given Computer-Aided Design (CAD) model. The solution strategy for the formulated linear mixed-integer optimisation problem is presented. The algorithmic strategy for solving the resulting mixed-integer programming problem is also provided with examples that illustrate the effectiveness and efficiency of the approach.

Keywords:

• computer-aided mould design
• multi-piece moulding
• rapid tooling
• mixed-integer programming

Acknowledgments

The authors acknowledge Professor Satyandra K. Gupta at the University of Maryland for providing them the part models of Tests 4–8 and 10. The authors are also grateful to the comments and suggestions from the anonymous reviewers.