Types of SandUsed in Sand Casting
1. Green Sand
Green sand castings are made using sand molds, which are made from green sand containing water and an organic binding compound (also known as clay). The term green sand refers to sand molds that are not "set" or "uncured" or "uncured" when the metal is poured into the mold. Because sand can be reused, casting with green sand is easy and inexpensive. The downside is that sand is a soft mold that can collapse or shift during casting.
2. Water glass or sodium silicate
Sodium silicate can be used to make sand castings. This process is beneficial for sand casting where mold cavities are required. Sodium silicate can quickly change from a liquid to a solid by passing carbon dioxide through it. This causes the sodium silicate to dehydrate. Sodium silicate must be mixed with other materials to remove the core during the breakdown of the product. If the mixture is incorrect, the core will get stuck in the casting.
3. Resin sand
The molding material of resin sand casting is a mixture of quartz sand and resin sand. When resin sand is mixed and heated, it hardens into a strong, smooth mold. Solid molds produce fewer casting defects, but are more expensive and slower to produce. Resin sand molds take longer to make because each one must be mixed and fired individually.