Refractory coatings are applied to sand moulds and cores in foundries (steel castings, grey cast iron and ductile iron, and non-ferrous metals).
Refractory coatings provide a protective barrier between the molten metal and the mould or core substrate during the casting process, ensuring the integrity of the cast surface and preventing defects, such as segregations, burnt-in sand, bulges/recesses and other.
They reduce the thermal shock caused by sand substrate and reactions between the substrate and melt, strengthen the mould surface and give smooth surface of castings.
Different applying processes can be used for our coatings – dipping, spraying, pouring and applying with brush – providing flexible use in production processes specific to individual foundries.
Efficient coating must provide the following features:
- Sufficient refractory quality to prevent melt being pured into substrate
- Good adhesiveness to substrate and good covering characteristics
- No blistering, cracking and scaling tendency on drying
- Good suspension and mixing properties
- Good storage stability
- Good adhesiveness