Process Simulation-Based Design, Mold Construction and Mechanical Performance Evaluation of an Insert-Injection Molded Thermoplastic Polyurethane Part

Abstract

This paper presents a case study of simulation-based designand experimental validation of the insert-injection moldingprocess of a complex polyurethane part. The part under considerationis a dowel holder which is a machine element usedin the concrete railway sleepers production. A simulationstudy was carried out to define the relevant mold design optionsand optimal molding parameters as well as to evaluatetheir influence on the part?s quality indexes. Simulation wasperformed using the software Moldex3D. The mold was constructedaccording to the optimization analysis and a batchof pieces was manufactured under the optimized conditions.A mechanical testing experiment ? representing the actualservice loading conditions ? was designed and performed tovalidate the mold and process designs and the part performance.Simulation and statistical analysis results allowed determiningthose conditions that lead to a better assembly betweenthe part and the metallic insert and to its structuralintegrity. The mechanical performance evaluation demonstratedthat the part meets all its functional and structural requirements,validating simulation predictions.