Dry Sand Moulding

Dry Sand Moulding :

Introduction:

     Dry sand casting is a sophisticated form of green sand process, in which the sand mold is baked at a given temperature to make it stronger. This process in mostly used in large foundries to produce big ferrous and non-ferrous castings like engine blocks, construction parts, etc. Dry sand casting ensures precise size and perfect dimensions.

      The factors affecting the casting process is the proper baking of the mold and the accurate consideration of size, weight and mass of the casting. The key to this process is the proper baking time in relation to the binder and the moisture content.

Process:

     A chemical or adhesive binder is mixed with unbounded sand and then it is shaped in the form of the the mold or pattern. It is then baked at a specific temperature. Very intricate designs that are required for housing constructions and automotive parts can be molded perfectly by this method. When the mold is ready, the pattern made of wood, rubber or other material is set in the mold. Intricate pattern, spures and cores can be used in this method. The patterns is a exact replica of the shape that the metal is to casted in. Molten metal in poured into the mold where it solidifies. When the casting is complete, it is removed from the mold. For the best results in dry sand casting baking of the mold should be properly baked at a given temperature and the proportion between the binder and the moisture content should be maintained. Though the process is quite expensive this process produces exact result when casting large and heavy operation casting.

Applications:

     Both ferrous and non-metals can be cast using the dry sand cast method. This process is largely used for producing intricate designs for heavy applications. Some of the casting that are produced are engine blocks, large gears, big housings, construction parts, big gear boxes, transmission housings, agricultural casting, automotive parts, etc.

Advantages:

• Complicate designs required for engines and automobiles can be designed with relative ease
• Accuracy is terms of dimensions, size, designs, is the main benefit
• Though an expensive process, here accuracy is maintained in every respect
• A process is favored by large foundries.