The characteristics of chemical hardening sand casting process are:
① The strength of chemically hardened sand mold is much higher than that of clay sand mold, and after being made into sand mold, the film will be removed after hardening to a fairly high strength, so there is no need to repair the mold. Therefore, the mold can accurately reflect the size and outline shape of the pattern, and it is not easy to deform in the later process. The size accuracy of sand mold casting is high.
② Because the viscosity of the binder and hardener used is not high, it is easy to mix with sand particles. The sand mixing equipment has the advantages of light structure, low power and high productivity. The work part of sand treatment can be simplified.
③ The mixed molding sand has good fluidity before hardening, and the molding sand is easy to pound during molding, so there is no need for a huge and complex molding machine.
④ When molding with chemically hardened sand, pattern materials such as wood, plastic and metal can be selected according to production requirements.
⑤ The content of binder in chemically hardened sand is much lower than that of clay sand, and there is no powdery auxiliary material. If raw sand with the same particle size is used, the gap between sand particles is much larger than that of clay sand. In order to avoid metal infiltration between sand particles during sand mold casting, the surface of sand mold or core shall be coated with high-quality coating.
⑥ The chemically hardened sand using glass as binder has the advantages of low cost and odorless working environment. However, after pouring metal, the molding sand is not easy to collapse; The used old sand can not be recycled directly, but must be recycled, and the regeneration of sodium silicate sand is more difficult.
⑦ The cost of chemically hardened sand with resin as binder is high, but after pouring, the sand castings are easy to be separated from the molding sand, the workload of sand casting cleaning is reduced, and most of the used sand can be recycled.