S&B Industrial Minerals has developed a special additive, ANTRAPEX, that has become a permanent component in the moulding materials used for core making. ANTRAPEX is a mixture of synthetic, organic and inorganic constituents  that are added to the core sand in order both to avoid veining and to improve the casting surface.

As a result, the need for core coating can be extensively or even completely eliminated. When casting the core packages or in moulds containing cores that have been prepared with the ANTRAPEX additive, the ANTRAPEX component undergoes plastification, i.e. it softens, thus filling the pores and forming lustrous carbon. This plastification reduces the compressive stresses and thus the tendency toward veining. Closing of the porous cavities and reducing the degree of wetting of the mould by the molten metal results in less penetration and thus in an improvement in the component’s as-cast surface.

Benefits: Casting surfaces of near-perfect finish; significantly reduced expense in terms of core coating operations and casting machining/rework; significantly reduced gas formation in the core.

Following core breakdown, the residues land in the bentonite-bonded moulding sand, again contributing to significant improvements in the casting surface through the formation of lustrous carbon.

                   with Antrapex                             without Antrapex