Defect Reduction in Injection Process of Printer's Parts using the Design of Experiment (DOE) Technique

Abstract

The objective of this research was to reduce any defects in injection process of printer's parts using the theory of the plastic injection and Design of Experiment (DOE) technique for a cause analysis and impact factors on the quality of product. The research methodology included the determination of possible causes of defects with a fish bone diagram and the use of FMEA to the select top of 3 important factors. Next step was to test level of significance with 2[superscript 3] full factorial design with some repeating, number of block I and 95% confidence level. Levels of three factors were Mold Temperature at 35 degree Celsius and 45 degree Celsius Cycle Time at 34 sec. and 38 sec. and Holding Pressure at 30 and 40 MPa. The result showed that the optimal level are the mold temperature at 45 degree Celsius, the cycle time at 34 sec. and holding pressure at 30 MPa, which can reduce defect rate from 77.7% to 05.3%