A Plastic Injection Molding Process Characterization Using Experimental Design Technique: A Case Study

Abstract

Kertas kerja ini mengillustrasikan applikasi reka bentuk eksperimen dalam industri pemprosesan suntikan plastik untuk salah satu komponen penyaman udara. Objektif utama reka bentuk eksperimen ini ialah untuk mengenal pasti parameter mesin suntikan plastik dan seterusnya menentukan paras optima mesin yang mempengaruhi karekteristik output, iaitu short–shot. Reka bentuk factorial penuh telah dipilih untuk kajian ini dengan mengenal pasti lima mesin parameter, iaitu backpressure, screw rotation speed, spear temperature, monifold temperature, dan holding pressure transfer. Keputusan kajian telah dapat mengenal pasti mesin parameter yang mempengaruhi karekteristik output dan mesin parameter signifikasi tersebut telah dianalisa melalui model regrasi. Kata kunci: Reka bentuk eksperimen, mesin suntikan plastik, analisa varian, analisa regrasi This paper illustrates an application of design of experimental (DOE) approach in an industrial setting for identifying the critical factors affecting a plastic injection molding process of a certain component for aircond assembly. A critical to quality (CTQ) of interest is reducing process defects, namely short–shot. A full factorial design was employed to study simultaneously the effect of five injection molding process parameters. The five process parameters are backpressure, screw rotation speed, spear temperature, manifold temperature, and holding pressure transfer. Finally, the significant process parameters influencing the short–shot defect have been found. Empirical relationship between CTQ and the significant process parameters were formulated using regression analysis. Key words: Design of experiments, injection molding, analysis of variance (ANOVA), regression analysis