Optimization of Injection-Molding Process of Short Glass Fiber and Polytetrafluoroethylene Reinforced Polycarbonate Composites via Design of Experiments Method: A Case Study

Abstract

This study analyses the tribological behaviors and mechanical properties of polycarbonate (PC) reinforced with 20% short glass fiber (SGF) and 6% polytetrafluoroethylene (PTFE), which is applied to the bottom cover of the card reader body. In order to reduce the number of experiments, the design of experiments (DOE) method based on Taguchi's orthogonal arrays were applied. The specimens were prepared under different injection molding conditions by varying four controlled factors including the filling time, the melt temperature, the mold temperature and the packing pressure with three levels for each factor. The wear mass loss, the friction coefficient, and the strain are adopted as the quality targets. In addition, an optimal parameter setting is obtained through a desirability function that balances three desired quality targets. Furthermore, analysis of variance (ANOVA) is conducted to identify the factors that have significant influence on the quality of the products. The proposed approach offered an effective and systematic way to identify an optimal setting of the injection molding process.

Keywords:

• DOE
• Injection molding
• Mechanical properties
• Optimization
• Tribology properties

ACKNOWLEDGMENTS

The authors would like to thank the National Science Council of the Republic of China, Taiwan for financially supporting this research under Contract No. NSC93-2212-E-159-001.