Optimizing The Casting Development Process In A Foundry Through Six Sigma

Abstract

In the current scenario of mass production, quality is a very important parameter for acceptance of a product by the customer. Firms are competing for achieving the closest tolerance provided by the customer, whereas reducing the defects and achieving maximum profit margins are in house challenges. Despite modernization in manufacturing processes like 3D printing and advanced CNC machining that can achieve tolerances in microns, casting foundries still dominate mass production because of their inherent cost-effectiveness and reproducibility. Even with new methods and techniques implemented in recent years, foundries struggle to reduce the casting defects and losses which occur during the casting processes. This paper reports an experimental investigation carried out at a small-scale foundry which manufactures hubs, flywheels, and brackets in S.G. and C.I., with the aim to reduce casting losses. This applied research project was focused on the development phase, where defect rates can even go above 50%. By applying Six Sigma methodology and DOE for the sand moulding process, the authors were able to help the foundry achieve significant reduction in the defect rate for the development of raw manifolds from 29.24% to 5.42%.