Abstract
The main aim of the foundry industry is to produce quality castings with no rejection. Also, in the present era of global competition, manufacturing industries are bound to take the challenge of demand for high quality product with reduced lead–times. Nevertheless, the diversity of greensand casting parameters results in varying effects on the quality of castings.
With sand being one of the most frequent cause of quality reject/rework, it is essential to understand the effect it has on the casting outcome. Taguchi’s approach in quality states that the quality of a product is dependent on the input, as a result he figured that the perfect time to eliminate differences in products is during the designing and manufacturing of products, and as such developed a strategy for quality that can be used in the process. Therefore, it is important to understand the inputs in sand mould preparation.
The focus of this research is on sand moulding process. From this study, it is found that the casting defect is the most contributing factor to quality reject in most foundries. In particular, sand moulding process is the most contributing factor to the formation scrap. The target in foundries is to achieve lower number of defected castings, resulting to minimal financial losses.
Using this method, this study successfully identified sources of casting defects that are related to sand which were blows and managed to come up with remedies to reduce blows due to sand by focusing on the permeability of the sand. This study further found that the best way to effectively and efficiently reduce sand defects is to have a good quality management system, by simply collecting all data from sand, defects and keep records for a number of years. Collecting and keeping records assists in the understanding of the variation in parameters and therefore detect which adjustments to make if there is an occurrence of defects.