Ferrous Metal Shell Casting – Gray Cast Iron Investment Casting – RMC Foundry

Shell mould casting is a process in which the sand mixed with a thermosetting resin is allowed to come into contact with a heated metallic pattern plate, so that a thin and strong shell of mould is formed around the pattem. Then the shell is removed from the pattern and the cope and drag are removed together and kept in a flask with the necessary back-up material and the molten metal is poured into the mould. 

Shell mold casting process offers better surface finish, better dimensional tolerances, and higher throughput due to reduced cycle times. The materials that can be used with this process are cast irons, and aluminum and copper alloys. The shell molding process produces cost savings solutions for difficult shapes, pressure vessels, weight sensitive parts, and castings requiring superior surface finishes. 

The basic characteristics of self-hardening molding casting process are:

• 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.