The production of castings using shell moulding (the Croning method) has a long-term tradition in ČZ (since 1956). A combination of shell mould and shell cores is used almost exclusively.
This technology enables the production of castings of high surface quality, dimensional accuracy and relatively complex shapes. It permits production of castings with minimum machining allowances. Shell moulds and cores are produced by shooting and blowing on Hottinger and Shalco machines, while some moulds are produced using mould-making machines with an ASF-ČZ tipping case.
The basis for mould production is the COATED SAND. This moulding material is almost 100% recycled after casting and knocking out of castings in the thermal reclamation unit and reused for further mould and core production. The foundry production of ČZ minimally burdens the environment by the depositing of foundry sand and other waste.
The finished shell mould ready for casting is loaded into a transport trolley on the foundry line using a handling robot and after passing it through the cooling tunnels; castings are automatically knocked out then. The FDC foundry line is industrial-computer controlled and all transport of moulds, castings and auxiliary materials is managed within controlled cycles using hydraulic manipulators and vibrating transporting troughs. Only mould loading, pouring and removing of raw casts at output from the cooling tunnel are performed manually.