Shell Mouldings‐a New Foundry Technique: A Brief Account of Developments in the Production of Castings Since the Introduction of Synthetic Materials

THE process known as Shell Moulding is the most important of a number of changes which have been brought about by the introduction of plastics into foundry technique. These changes result from the use of thermo‐setting resins in foundry sand to bind it, and depend on the temperature properties of the resin, which enable it to be cured at a moderate temperature so as rigidly to bind the mould, while the temperature of the melt is high enough to break down the resin again so that the mould falls away after the casting has been poured.