V casting process

V casting process

V method casting is vacuum sealing modeling. The principle is to use plastic film to seal the sand box, and use a vacuum pump to extract the air in the mold to form a pressure difference inside and outside the mold to make the dry sand tight to form the required cavity. The biggest advantage of V-method casting, which is different from traditional sand casting, is that no adhesive is used, thus reducing the sand treatment work, and the labor of modeling and casting sand cleaning is also greatly reduced, and the recovery rate of old sand can reach more than 95%.

The castings produced by the V-method casting process are of good quality, smooth surface, clear outline, accurate size, and uniform hardness, which effectively extend the service life of the castings, and are praised by users and become the new favorite of the industry.

Both V-method casting and lost foam casting adopt Vacuum forming, but the technological processes of the two are quite different. Vacuum process casting is named after taking the prefix "V" of the English word Vacuum. It is different from the traditional sand casting. The biggest advantage is that no adhesive is used. The V-method casting uses plastic film to seal the sand box, and the air inside the mold is extracted by the vacuum pumping system. There is a pressure difference inside and outside the mold, the dry sand is dense to form the required cavity, and the casting is solidified by the lower core, the box is combined, and the casting is vacuumized to relieve the negative pressure, and the sand is then collapsed to obtain the casting.

Compared with traditional sand casting, V-method casting and lost foam casting have the following advantages:

first, because of the use of negative pressure casting casting sand hole pores, high product density, smooth surface, clear outline, accurate size;

second, energy-saving, efficient and clean production. Adopt V method and lost foam technology can make dry sand use repeatedly, without drying type, coal consumption is reduced, but due to long-term vacuum machine operation, power consumption is slightly increased, but greatly reduce dust and save human capital, make the casting work more effective, save labor and greatly reduce labor intensity, less harmful gases in the pouring process, and truly realize environmentally friendly production.

The key point of V-method production is to select the vacuum pumping system. When selecting the vacuum pumping system, the capacity of the vacuum pump must be determined first, mainly considering the following factors:

1. The size and quantity of sand boxes that need to work under vacuum at the same time;

2. The number of molds poured at the same time;

3, pouring size and shape;

4. The air permeability of the mold surface close to the film controls the amount of air entering the mold through the cracks in the plastic film. Therefore, it is necessary to use a small amount of mold coating during pouring, it helps to provide an "auxiliary sealing layer" for the vacuum machine ".