Hybond bentonite additives

Tolsa SA, Madrid, has developed its Hybond bentonite additives specifically for green sand foundries to ensure consistent homogeneity and thermal stability of green sand, according to the company.

The supplier's portfolio includes binder additives made from high-quality bentonites extracted from its own mines worldwide. According to the company, the Hybond bentonites are produced from high-purity bentonite, then ground and classified to obtain a consistently dry powder that exhibits high compressibility in the dry state and very good crushing properties. Thanks to their homogeneity, the natural sodium and calcium activated Hybond bentonites are said to provide mould stability throughout the casting process. They are said to ensure not only excellent mould strength and durability, but also high wet tensile strength, resulting in fewer casting defects. They also promise high agglomeration rates, high flowability in sand through controlled compactability, high durability and excellent thermal resistance. This reduces bentonite consumption as well as fine dust and moisture. The additives are equally suitable for iron, steel, aluminium or copper castings.