Sand mold , also known as sand casting , is sand which when moistened and compressed or oiled or heated tends to pack well and hold its shape. It is used in the sand casting process to prepare mold cavities.
Video Molding sand
Green sand
Green sand is a sand aggregate, bentonite clay, coal powder and water. Its main use is making molds for metal casting. The largest part of the aggregate is always sand, which can be silica. There are many recipes for the proportion of clay, but they all have a different balance between moldability, surface finish, and the ability of hot metal molecules to degass. Coal, commonly referred to as marine coal, is present at a ratio of less than 5%, partially burning on the surface of molten metal that causes the offgassing of organic vapors.
Sand casting is one of the earliest forms of casting practiced because of the simplicity of the materials involved. It's still one of the cheapest ways to get rid of metal because of the same simplicity. Other casting methods, such as those using coquille, have higher surface finish quality, but have a higher cost.
Green sand (like other casting sand) is usually stored in what the caster calls "pumpkin", which is nothing but a bare or closed box. The box is divided into two parts which are arranged together used. This section is referred to as the top and bottom flasks respectively.
Not all green sand is green. But it is considered "green" as in the sense that it is used in a wet state (similar to green wood). According to the Cast Metal Federation website, the alternative casting method is to heat the dry sand before pouring molten metal. This dry sand casting process produces a more rigid mold that is more suitable for heavier castings.
Maps Molding sand
See also
- Overcome and drag
- DISAMATIC
- Testing of foundry sand
- Hand prints
- Sand casting
- Sand rammer
- Seramsite sand
Source of the article : Wikipedia
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