3. models, materials used in small amount of surface treatment materials and mass production with a metal or resin, filler with high purity, high melting point of refractory material in order to prevent and respond to molten metal, its material depends on the kind of casting metal, particle size distribution of refractory material is big particles mixed with small particle powders, moderate strength and surface can be obtained, gel used for the purpose of promoting agent is to accelerate the curing of bond, the use of alkaline substances such as general ammonium carbonate, etc.Above to everyone lost wax casting and the difference of the ceramic shell mold method believe that everybody should know that how to reasonable application of two kinds of methods to use should be more clearly!