HA-Ilarduya provides a great variety of pre-coated sands matching customer requirements. A pre-coated sand is commonly silica sand lightly coated with phenolic resin and used in foundry cores and moulds manufacturing through shell moulding (Croning process), that consists of putting in contact the pre-coated sand with a hot metal mould so that melted resin creates a sand shell around the mould.
The resulting cores have high mechanical strength and casted pieces present outstanding surface properties and top dimensional accuracy.
Pre-coated sand design is closely related to the kind of piece to be casted and the moulding process (dumping or shooting) to be used.
Core shape, casting alloy and surface quality requirements in the casted product significantly determine parametres such as sand AFA index or additives incorporation like organic compounds, magnetite, chromite, etc.
Pre-coated sands have unlimited bench life and endless storage time; furthermore, their high fluidity allows filling any mould shape, thus producing low weight hollow cores with less amount of sand.
Hüttenes Albertus offers a wide range of pre-coated sands for cores and Shell moulding, and also tailored solutions when necessary.