PRODUCTION OF FOUNDRY SAND MOULDS AND CORES

摘要

Foundry sand cores are produced by a method comprising the steps of: (1) providing a core box to contain the core, (2) injecting into the core box a mixture of sand and a binder capable of being cured by means of carbon dioxide gas so as to form the core, (3) passing carbon dioxide gas under pressure into the core box so as to fill the core box, (4) holding the core in contact with the carbon dioxide gas so as to cure the binder, (5) releasing the pressure and allowing carbon dioxide gas to escape from the core box, and (6) removing the cured core from the core box. The method can also be used to produce moulds and is of particular use in the production of cores or moulds from a mixture of sand and a binder consisting of an alkaline aqueous solution of a phenolformaldehyde resin and an oxyanion such as borate capable of forming a stable complex with the resin.