The manufacturing process can involve different stages, with sand casting being one of its most critical aspects. Casting involves pouring liquid material into a mould to shape it as it solidifies. The casting is then ejected or removed from the mould to be used for manufacturing equipment or machinery. The most common materials that are used in the process are concrete, epoxy, clay, plaster, and sand, and the process is conducted in a sand casting foundry, a specialized factory that is well-equipped for the job. Around 70 percent of every metal casting produced is created using the sand casting process, as it is typically cost-effective and produces durable parts.
Two types of sand moulding casting processes may be used in a sand casting foundry, namely green sand and the air set method. Green sand castings are created from sand moulds, which are formed from ‘wet’ sand (also called, ‘clay’) containing organic bonding compounds and water. It gets its name from not being ‘set’ and still in the uncured or ‘green’ state, even as the metal is introduced into the mould. Air set casting method uses dry sand, which is bonded with clay and other materials, and a fast-curing adhesive.
When deciding on which sand casting process to do, a sand casting foundry looks into the type of moulding process and the sand to be used. The accuracy of each method will depend greatly on those factors, too. One of ways to determine coarse green sand is its ability to cause a surface texture that is rough. Castings created using fine green sand may shine, but there could be limitations to the pockets in a pattern’s depth to width ratio. If you require a smoother surface, air set mould can be a better choice. Castings made with the air set method often have a burnt colour on their surface, and they are typically preferred when a pattern must have deep narrow pockets