The process of cleaning precision castings from the mold, removing excess parts other than the main body, and polishing the inner and outer surfaces of the castings.

De-coring and surface cleaning:

Divided into two categories, dry and wet. Dry cleaning is the use of mechanical equipment to clean the castings. The equipment is simple, the production efficiency is high, and it has the advantages of greater adaptability to different types of castings and can remove the core and effectively clean the surface. The disadvantage is that the equipment is running. In general, the dust is flying, the noise is large, and the environment is polluted. Wet cleaning has no dust, but because water is used as the medium, the surface of the casting is easy to rust. A large amount of sewage and cement sand are generated in the work process, which causes problems such as the regeneration of sand and water and sludge treatment.

The dry and wet cleaning methods commonly used in production are:

1. Roller cleaning. Put the casting and the star iron into the round drum together. When the drum rotates, the sand inside and outside the casting will be removed due to the collision and friction between the casting, the star iron and the waste sand. Polishing the surface of the castings can also partially clean the flash and burrs. This type of equipment can be used to clean small and medium-sized castings with simpler appearance and thicker walls.

2. Shot blasting. The impact force of high-speed steel shot, iron shot, and abrasive flow is used to clean the core, sticky sand, and polish the surface of the casting. In addition, the common shot blasting equipment also has a shot blasting cleaning table and a shot blasting cleaning room for development. Continuously produced shot blasting machines include chain-type shot blasting drums, continuous shot blasting cleaning tables, suspended continuous production shot blasting cleaning rooms, etc. These types of equipment have high operating and maintenance costs.

3. Hydraulic sand removal. Shoot high-pressure water from the nozzle of the gun to the cast part to be disposed of according to the pipeline, and use the kinetic energy and scouring effect of the water flow to clean the core and the casting sand. The hydraulic sand cleaning is generally equipped with an open cleaning chamber composed of section steel and steel plate, with a rotation at the bottom. The working table and the spray gun are installed on the side wall, which can move up and down and rotate, so that the high-pressure water can be sprayed to any part except the bottom surface of the casting. Sometimes, in order to better improve the efficiency of cleaning the sand on the surface of the Precision Casting, the spray gun Quartz sand and other abrasives are introduced into the appropriate position to obtain high-speed water sand flow. This method is generally called water sand cleaning.

4. Water explosion to clear sand. After the mold is poured, the precision casting is boxed when it cools to the specified temperature, and it is immediately immersed in the pool. The water penetrates into the mold through all the gaps and contacts the high-temperature metal quickly, vaporizes and explodes. The shock wave can basically clean the sand attached to the inside and outside of the casting. The water explosion sand cleaning method has the advantages of short working time and high efficiency. It is widely used in domestic Steel Casting workshops. It is generally used to dispose of steel castings with a carbon content of less than 0.35%.