Silica sand is the most commonly used sand because of its great abundance, and, thus, low cost (therein being its greatest advantage). Its disadvantages are high thermal expansion, which can cause casting defects with high melting point metals, and low thermal conductivity, which can lead to unsound casting. It also cannot be used with certain basic metal because it will chemically interact with the metal forming surface defect. Finally, it causes silicosis in foundry workers.
Chromite sand
Chromite sand is a solid solution of spinels. Its advantages are a low percentage of silica, a very high fusion point (1,850 °C (3,360 °F)), and a very high thermal conductivity. Its disadvantage is its costliness, therefore its only used with expensive alloy steel casting and to make cores.
Resin
Resin binders are natural or synthetic high melting point gums. The two common types used are urea formaldehyde (UF) and phenol formaldehyde (PF) resins. PF resins have a higher heat resistance than UF resins and cost less. There are also cold-set resins, which use a catalyst instead of a heat to cure the binder. Resin binders are quite popular because different properties can be achieved by mixing with various additives. Other advantages include good collapsibility, low gassing, and they leave a good surface finish on the casting.
Founded in 1997,Haian Haitai Casting Co.,Ltd. is the leading manufacturer of large-scale cement and marine sand casting products in the north of Jiangsu Province. Its main products include rudder blade, quill shaft,anvil stand,support roller,cast steel joints for bridge,gear,integrated chassis,steel bracket,rudder pintle, sternpost, chain wheel, slag pot with the material of carbon steel,low alloy steel and so on.More than 20 years experience, we now have one set of 8 tons of electirc arc furnace(maximum casting 28T) and two 20 tons high-frequency furnace.The annual capacity is 20000 tons and the maximum casting can be 60 tons.Your visit to our factory will be warmly welcomed.
