Parametric Analysis and Quality Improvement of Mould Filling Process for the Manufacturing of a Car Side Mirror Cover: A Case Study

Abstract

The aim of this research paper is to reduce the defects rate and process variation during production of car side mirror plastic cover. The main purpose of this research study is first one to recognize the root cause analysis of quality problems as well as other surface marks on car side mirror plastic cover. The second purpose is to implement sigma with DMAIC to improve the quality of car side mirror plastic cover. A plastics industry in Pakistan has many quality problems during the production of car side mirror plastic cover such as black dots, air bubbles, flow marks and part hard fitting. Due to process variation, non-conformity increases and poor-quality parts are produced. The industry faces high percentage of wastage, production cost and low customer's satisfaction due to low quality of mould part. The major rejection of moulded part is found due to hard fitting, black dots, air bubbles and flow marks. The Six-sigma with DMAIC (Define, Measure, Analysis, Improve, and Control) was applied to overcome these quality problems and process variation. DMAIC is an engineering technique that can be used in service and production which requires a practical solution. This improvement technique is applied on injection moulding machine 360 tone Tederic manufactured by china Model 2005 which has major rejection rate. This machine had 35% rejection of total rejection before improvement. After development, it reduced to 16%. Four major quality problems are removed and increased the quality level and customer's satisfaction. The reduction of rejection rate and wastage has saved company time, money and improved company sigma level.