Inorganic binder material for core-making

In order to reduce the consumption of organic binding material, which is responsible for emissions and odour in foundries (which can lead to complaints from neighbours), different compositions of inorganic binding materials have been developed for use in core-making in aluminium die-casting and have already been used in the series production of intake pipes for 

The cores are produced using a binder that contains magnesium sulphate and/or polyphosphate. The inorganic binders consist essentially of salt-water mixtures, as well as small amounts of additives (e.g. ceramic) to prevent sand adhering or sticking to the casting. The proportion of binder relative to the quantity of sand by weight is 3 to 8%. About half of this amoimt is solvent and crystal water. 

The different sand flowing properties will require revision of the core models and venting upon implementation of this technique in an existing plant. In the drying step, all the moisture needs to leave the core, a requirement which may limit the core dimensions. 

The ceramic additives contained in the binder eliminate the need to coat the cores. 

When a dry technique is used for core removal, all the binder remaining in the sand can be reused. 

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