With the advancement of science and technology and the vigorous development of the foundry industry, different casting methods have different mold preparation contents. Taking the most widely used sand casting as an example, the preparation of the mold includes two major tasks: material preparation and molding and core making. Various raw materials used for modeling and core making in sand casting, such as raw casting sand, sand binder and other auxiliary materials, as well as molding sand, core sand, coatings prepared from them, are collectively referred to as modeling materials. The task of modeling materials preparation According to the requirements of the castings and the properties of the metal, the appropriate raw sand, binder and auxiliary materials are selected, and then they are mixed in a certain proportion into molding sand and core sand with certain properties. Commonly used sand mixers include roller type sand mixers, countercurrent sand mixers and continuous sand mixers. The latter is specially designed for mixing chemical self-hardening sand, continuous mixing and high sand mixing speed.
Modeling and core-making are carried out on the basis of determining the modeling method and preparing the modeling materials according to the requirements of the casting process. The accuracy of the casting and the economic effect of the entire production process mainly depend on this process. In many modern casting workshops, modeling and core making have been mechanized or automated. Commonly used sand moulding core making equipment include high, medium and low pressure moulding machines, air jet moulding machines, boxless injection moulding machines, cold core box core making machines and hot core box core making machines, coated sand core making machines, etc.
After the casting is taken out from the pouring and cooling mold, there are gates, risers, metal burrs, and drape seams. The sand castings still adhere to the sand, so they must go through a cleaning process. The equipment for this kind of work includes polishing machine, shot blasting machine, pouring riser cutting machine and so on. The falling sand cleaning of sand castings is a process with poor working conditions. Therefore, when choosing a molding method, try to create convenient conditions for falling sand cleaning. Due to special requirements, some castings have to undergo post-casting treatments, such as heat treatment, shaping, anti-rust treatment, and rough machining.