Shankaranarayana, R., "Application of Six Sigma Methodology to Improve Product Quality in Injection Molded Parts at Supplier End in Motorcycle Industry," SAE Technical Paper 2017-01-5011, 2017.
Process Parameters play a vital role in product quality of Injection Molded components. Variation in process parameters will lead to Injection Molded manufacturing defects like Sink Mark, Flow Mark, Silver Streak, Flash, Warping, Weld lines, Jetting, voids, Short Shot & Bubbles. This manuscript is innovative because suppliers (Tier 1 and Tier 2) do not use DoE for standardization of their process parameters in Injection Molding and High Pressure Die Casting. They do trial and error method to arrive at the process parameters which is error prone and time consuming.The variation of process parameters can be optimized using Six Sigma approach, a structured methodology which is Process focused & data driven approach. The purpose of this paper is to present through a case study how the concepts of Design of Experiments, which is a part of Six Sigma Methodology can be used for improving the Injection Molding Process at supplier end reducing defects & hence improving Quality at supplier which stops 100% BOP inspection and segregation when the parts reach the OEM. Here one of the products in Motorcycle Industry has been taken which has 100% Sink Mark defect & resulting in 100% rework. By following the six sigma DMAIC approach and using tools like SIPOC, PMAP, Fish Bone Diagram, Cause and Effect Matrix & Design of experiments to optimize the process parameters at supplier Injection Molding Machine through cross functional team approach. The result has proved that the quality of the product in automotive Industry can be improved by using Six Sigma Approach. This approach can be used for all suppliers and all OEMs or can be horizontally deployed in the Injection Molding Process and High Pressure Die Casting Process to reduce defects and improve product quality by reducing process variation.