Comparative analysis of materials during design process of prosthetic foot by using plastic injection molding simulation FE tool

A comparative analysis between polymeric materials suggested for a new design of a Dynamic Energy Return (DER) prosthetic foot is presented. This component, developed in the R+D Biomechanics Group of the Universidad Simón Bolívar, conforms a solid block of some 400 cm³, which is unusual in injected plastic parts and requires particular requirements not covered by conventional standards for correct design of an injection mold. Numerical tests were conducted using a plastic injection molding simulation tools. Results related to Filling Time of the cavity mold, Cycle Time, Volumetric Shrinkage, Warpage and Sink Marks of molded part in Polyoxymethylene (POM), polyamide (PA) and polypropylene (PP) are presented and discussed contrasted with the recommendations of the technical bibliography reports, usually for injection of thin-walled parts.