An Introduction to Sand Casting

Source : VARUN METAL FOUNDRY

Sand casting is the most common technique used around the world. A typical process flow of sand casting is shown in the following diagram: 

Sand is used as a refractory material in sand moulding systems. Sand casting process is a binder maintains the shape of the mould while pouring molten metal. There is a wide range of sand/binder systems that are used in sand casting system. Bentonite clay is used upto 4-10% of the sand mixture in Green sand systems, which is the most common sand casting system. Water, which makes up around 2-4% of the sand mixture, activates the binder. Carbonaceous material such as charcoal (2-10% of total volume) is also added to the mixture to provide a reducing environment. It helps in preventing the metal from oxidizing while pouring. The remaining 85-95% of the total mixture contains sand.

A range of chemical binders is used by other sand moulding processes: Oil binders are mixture of animal oils, petrochemicals and vegetable. Some of the popular synthetic resin binders are: ureaformaldehyde, phenolics, phenolformaldehyde, urea-formaldehyde/furfuryl alcohol, alkyl isocyanate and phenolic isocyanate. Chemical resin binders are frequently used for foundry cores and less extensively for foundry moulds.

Varun Metal Foundry is the leading manufacturer of C.I. Casting, Gray C.I. Casting,Close Gray C.I. Casting, and Graded C.I. Casting. 

Posted By : Metal casting Company