Rejection Rate Reduction of the Automotive Thermoplastic Parts in Injection Moulding Using Response Surface Methodology

Abstract

Plastic injection moulding is widely used for manufacturing due to variety of plastic product. In this study, plastic part defects such as air bubble and gas mark defect are commonly occurs in thermoplastic part, specifically acrylonitrile butadiene styrene (ABS). In order to optimize the process parameters of injection moulding, design of experiment (DOE) with Response Surface Methodology (RSM) model was used. Process parameters such as melt temperature, mould temperature and injection pressure were selected for the DOE development. The experiments were conducted with melt temperature range from 200 °C to 240 °C, mould temperature from 60 °C to 80 °C and injection pressure from 90 to 99%. The result indicates that, all the selected parameters were significantly influence the rejection rate of the automotive ABS part. The optimum melt temperature, mould temperature and injection pressure were 220 °C, 70 °C and 98% respectively, in obtaining minimum rejection rate.