Integrated Robust Design Methodology and Dual Response Surface Methodology Approach in Optimization of Powder Coating Process

Abstract

Powder Coating (PC) is an economical and widely preferred surface finishing process. Powder coating being a special process has its share of quality-related problems. In this work, an attempt is being made to integrate Genichi Taguchi’s Robust Design (RD) methodology and Dual Response Surface (DRS) methodology. The main purpose of this research is to determine the various parameters that govern the quality characteristics of PC process and to further optimize the process to achieve the products critical-to-quality specifications nearer to the target value by reducing the process variation. The process under study is an electrostatic PC process done using a corona gun. The response output is dry film thickness whereas the input variables are high voltage, current limitation, total air flow, and feed air. RD method was used to predict the significant effects of parametric levels on the PC process. Further the DRS methodology was utilized to optimize the PC process. Confirmation experiment revealed that with the adopted methodology, it is possible to maintain the CTQ parameter nearer to target value of 100 microns with an acceptable variation.