Comparison of Bentonite and Cassava Starch on the Moulding Properties of Silica Sand

This work investigated the effects of Bentonite and Cassava starch binders on foundry moulding sand. The two binders were applied separately to silica sand in different proportions and also as a mixture in different proportions as well. The effects of these various additions on foundry moulding sand were investigated by conducting out various tests as permeability, moisture content, green compressive and green shear strength, dry compressive and dry shear strength as well as the AFS of the sand. The results showed that bentonite had better binding characteristics than cassava starch but a mixture of both in equal proportions gave a range of excellent mould properties that could be exploited in making moulds for different weights of castings. Permeability for the two binders decreased as the quantity of binder increased.