Gum Arabic, exudates of several species of acacia, is typical of gum that contains Arabin. Gum Arabic of finest quality is obtained from Acacia Senegal and A. Arabica found in western and northern Africa. The Gum forms a clear thick solution in water. In this work, the foundry properties of Gum Arabic were investigated to ascertain its suitability as a composite binder for core production.
Various percentages of Gum Arabic and some conventional foundry binders were prepared and their binding properties determined. Since the binder has low limit hydration, it does not require the use of much water during mixture preparation. For the purpose of this work, 4%-6% of the Gum Arabic was used with conventional binders like bentonite, water glass, industrial starch, linseed oil to prepare core mixtures. A higher percentage (13-15%) of Gum Arabic alone was also used. Foundry properties like permeability, scatter index; mould ability index, moisture content, compressive strength tests and refractoriness were examined. The results revealed that the binder has a low refractoriness of 1200°C. This has the advantage of enhanced and good collapsibility during knock out.