Drying of moulds and cores made using polymer foils and vacuum - where microwave energy is used to dry mould wash coating foils forming mould cavity

摘要

Polymer foils are drawn onto a pattern by suction, and are then coated with a slurry employed to improve the surface quality of the castings. The moulding boxes are next filled with sand or other moulding material. The moulds or cores are then dried using microwave energy and a vacuum which removes the gases and vapour created during drying. The pref. appts. includes a reflecting base on which the moulds are placed underneath a hood contg. microwave generators; and the vacuum removing gas and vapour is applied via suction channels in the walls of the moulding boxes. The slurry used as a mould wash is made using water or alcohol, which must be removed before casting. The invention provides very rapid removal of the water or alcohol.