1) General coated sand

Ordinary coated sand is the traditional coated sand. Its composition is usually composed of quartz sand, thermoplastic phenolic resin, urotropine and calcium stearate without additives. Its resin content is usually relatively high under certain strength requirements. It does not have the characteristics of high temperature resistance, low expansion and low gas evolution. It is suitable for castings with low requirements.

(2) Coated sand with high strength and low gas generation

Characteristics: High strength, low expansion, low gas evolution, slow gas evolution and oxidation resistance: High strength and low gas evolution coated sand is a renewal product of common coated sand. By adding some additives and adopting new formulation technology, the amount of resin used is greatly reduced. Its strength is over 30% higher than that of common coated sand, its gas evolution is significantly reduced, and its gas evolution speed can be delayed, and it can be more effective. It is well suited to the needs of casting production. This kind of coated sand is mainly suitable for the production of cast iron, medium and small steel castings and alloy steel castings. At present, there are three series of coated sand: GD-1 high-strength low-gas-generating coated sand; GD-2 high-strength low-expansion low-gas-generating coated sand; GD-3 high-strength low-expansion low-gas-generating anti-oxidation coated sand.

(3) High temperature resistant (class) coated sand (ND type)

Features: High temperature resistance, high strength, low expansion, low gas evolution, slow gas evolution, easy collapsibility and oxidation resistance: High temperature resistant coated sand is a new type of coated sand with excellent high temperature performance (high strength at high temperature, long heat resistance time, low thermal expansion, low gas generation) and comprehensive casting performance produced by special process formulation technology. This kind of coated sand is especially suitable for the production of complex thin-walled precision iron castings (such as automotive engine cylinder block, cylinder head, etc.) and high-requirement steel castings (such as container angle and brake brake brake brake brake brake brake brake brake brake brake brake brake brake brake, etc.). It can effectively eliminate casting defects such as sand sticking, deformation, hot cracking and air holes. At present, there are four series of coated sand: VND-1 high temperature resistant coated sand, ND-2 high temperature low expansion low gas generating coated sand ND-3 high temperature low expansion low gas oxidation resistant coated sand ND-4 high temperature high strength bottom low expansion low gas generating coated sand.

(4) collapsible coated sand

It has good strength and excellent collapsibility at low temperature. It is suitable for producing non-ferrous metal castings.

(5) other special requirements of coated sand

In order to meet the needs of different products, a series of special coated sand have been developed, such as centrifugal casting coated sand, chilled coated sand, wet coated sand, anti-sticking sand, anti-vein grain, anti-orange peel coated sand, etc.