Optimization of Injection Molding Process for Tensile and Wear Properties of Polypropylene Components via Taguchi and Design of Experiments Method

Abstract

This study analyzes the wear and the tensile properties of polypropylene (PP) components, which are applied to the interior coffer of automobiles. The specimens are prepared under different injection molding conditions by changing the melting temperature, the injection speed, and the injection pressure via three computer-controlled progressive strokes. The wear and tensile properties are adopted as the quality targets. Experiments of 16 experimental runs are based on an orthogonal array table, and apply the Taguchi method and the design of experiments (DOE) approach to determine an optimal parameter setting. In addition, a side-by-side comparison of two different approaches is provided. In this study, regression models that link the controlled parameters and the targeted outputs are developed, and the identified models can be used to predict the tensile and wear properties at various injection molding conditions.

Keywords:

• DOE
• Injection molding
• Optimization
• Taguchi
• Tensile stress
• Wear

ACKNOWLEDGMENT

The authors would like to thank the National Science Council of the Republic of China, for financially supporting this research (Contract No. NSC95–2622-E-159-01-CC3) and Ming Hsin University of Science and Technology (Contract No. MUST-96-ME-001).