Sand Mold Casting Process

Sand mold casting is one of the expendable mold casting processes. This is a very common method in local manufacturers. In this method, Foundry people use sand as the mold material and a small amount of clay use as the bonding agent. Sand and clay with small amounts of water use to improve cohesion and mouldability. Most foundries use silica sand (SiO2) as the mold material. There are two common sand types use in mold marking. Those methods are naturally bonded (bank sand) and synthetic (lake sand). Considering the accuracy of composition control, most foundries tend to use synthetic sand for their casting process.

Application of Sand Casting

• Machine frames and beds
• Gear of various shapes and sizes
• Casing and impeller of water pumps
• Turbines and other hydraulic equipment
• Railway items
• Aerospace parts
• Automobile parts
• Engine blocks
• Fan blades

Advantage

• Almost any material can use for the cast (Cast iron, Steel, Aluminium, Zinc, and Alloys)
• No limitation for part size
• No limitation for shape and weight of the part
• Low tooling cast
• Simple molding structure

Disadvantages

• Need some finishing operations
• Relatively coarse surface finish
• Wide tolerances

Sand Casting Operation

Sand mold is making use of various methods like:

• Vertical flask less molding
• Impact molding
• Vacuum molding.

After the mold has been shaped cope and drag parts can be closed and clamped. secondly molten is to prepared temperature can pour into the mold cavity. After solidification casting can take out using vibration or by sandblasting.

Types of Sand Molds

• Green Sand Mold
• Skin-Dried Mold
• Dry Sand Mold

The green sand mold is very common and widely used for ferrous and non-ferrous casting. Foundry people sand casting mixture make using sand, clay, and water. Sand is moist or damps while the molten metal is pouring into it. Skin- Dried sand mold is similar to Greensand mold with the sand mixture. Skin- Dried sand mold cavity is dried with warm air or flame to harden the surface & drive out moisture before the casting process. Bonding argent can use for the Skin-Dried sand molds. Dry Sand Moulds are thoroughly heated or baked until remove most of the moisture from the sand mold is. In this type of sand mold, all the sand contains the bonding urgent.