Incorporating Dimensional Requirements Into Material Selection and Design of Injection Molded Parts

This paper presents a methodology for incorporating part dimensional tolerancing into material selection for engineering thermoplastics. This work builds on the authors’ previous efforts on integration of mechanical performance and manufacturing cost into candidate design selection. The benefit of this approach is the simultaneous consideration of the implications of material selection and part geometry on estimated manufacturing cost during candidate design selection. The research approach uses the Pressure-Volume-Temperature (PVT) method to estimate shrinkage in thermoplastic parts. The authors then present a method for calculating production costs for meeting part tolerance requirements. Example calculations and a computer program illustrate the proposed methodology.