OPTIMIZATION OF MACHINE PARAMETER SETTINGS OF PLASTIC MOLDING INJECTION USING RESPONSE SURFACE METHODOLOGY REDUCING UNDER WEIGHT AND SHRINKAGE DEFECT

Abstract

Parameter machine settings make high variations which leads increasing various number of defect. At PT.ZXC, there were 103 customer complaints during 2016 - 2017, 38 of them came from machine problem, and 27 of customer complaint must be replace with 3,757,941 pieces of product cause of those various number of defect. Two of them which are underweight and shrinkage happened due to parameter settings still not standardize. Due to under weight complaint, there was 430,000 pieces must be replaced. While for shrinkage complaint, there was 50,400 pieces must be replaced. There is three parameter machine settings that frequently changed which are Holding Pressure (390 bars – 410 bars), Holding Time (1 second – 2 seconds), and Back Pressure (22 bars – 25 bars). By using RSM method, the result of response optimizer are Holding Pressure set on 399 bars, Holding Time set on 1.25 seconds, and Back Pressure set on 24.85 bars with 99% the model fit the data and also reduce cost of electricity up to Rp 513,728,-