Zhengzhou EverBright Machinery Co.,Ltd
Mobile : +8613213152686
Address: No.93 building, Headquarters Enterprise Base, High-Tech Zone, Zhengzhou City, Henan Province, China
The molding sand used in this sand type is called chemically hardened sand. The binder is generally a substance which can undergo molecular polymerization under the action of a hardener to form a three-dimensional structure, and various synthetic resins and water glass are commonly used. There are basically three ways of chemical hardening.
1. Self-hardening: Both binder and hardener are added during sand mixing. After the sand or core is made, the binder reacts under the action of the hardener to cause the sand or core to harden by itself. The self-hardening method is mainly used for styling, but it is also used to manufacture larger cores or to produce cores with a small batch size.
2. Aerosol hardening: Add binder and other auxiliary additives during sand mixing without first adding hardener. After molding or core making, a gaseous hardener is blown in or blown into the gaseous carrier to atomize the liquid hardener, which is dispersed in the sand or core, resulting in sand hardening. Aerosol hardening is mainly used for core making and sometimes for small sand types.
3. Heat hardening: Adding a binder during sand mixing and a latent hardener that does not work at room temperature. After the sand or core is formed, it is heated, at which time the latent hardener reacts with certain components of the binder to form an effective hardener that hardens the binder, thereby hardening the sand or core. The heat hardening method is mainly used for core making in addition to the small shell sand type.