China OEM custom alloy steel shell mold casting products. 

Shell molding casting process is also called pre-coated resin sand casting process, hot shell molding castings or core casting process. The main molding material is the pre-coated phenolic resin sand, which is more expensive than green sand and furan resin sand. Moreover, this sand can not be recycle used. 

The Advantages of Furan Resin Coated Sand Self-hardening Molding Casting:
1) Improve the dimensional accuracy of castings and the surface roughness.
2) The hardening of the mold (core) sand does not require drying, which can save energy, and inexpensive wood or plastic core boxes and templates can also be used.
3) Self-hardnening molding sand is easy to compact and collapse, easy to clean up castings, and old sand can be recycled and reused, which greatly reduces the labor intensity of core making, modeling, sand falling, cleaning and other links, and it is easy to realize mechanization or automation.
4) The mass fraction of resin in sand is only 0.8%~2.0%, and the comprehensive cost of raw materials is low.

Because the self-hardening method has many of the above-mentioned unique advantages, the self-hardening method is not only used for core making, but also used for casting moulding. It is especially suitable for single piece and small batch production, and can produce cast iron, cast steel and non-ferrous alloy castings. Some Chinese foundries have completely replaced clay dry sand molds, cement sand molds, and partially replaced water glass sand molds.