On V-method Casting
Vacuum process casting is named after the prefix "V" of the English word vacuum. The biggest advantage that distinguishes it from the traditional sand casting is that it does not use adhesive. V-method casting uses plastic film to seal the sand box, and draws out the air in the mold by the vacuum pumping system. There is a pressure difference inside and outside the mold, so that the dry sand is dense and forms the required cavity. After the core is lowered, the box is closed, and the vacuum is pumped by pouring to solidify the casting, relieve the negative pressure, and then the molding sand is collapsed to obtain the casting.
Advantages of V-method Casting Compared with Traditional Sand Casting:
1. The negative pressure casting has less sand holes and pores, high product compactness, smooth surface, clear outline and accurate size;
2. Energy saving, efficient and clean production. The use of V method and lost foam technology can make the dry sand reused without drying mold and reduce the coal consumption. However, due to the long-term operation of vacuum machine, the power consumption increases slightly, but the dust is greatly reduced and the human capital is saved, which makes the casting work more effective, saves labor and greatly reduces the labor intensity, and has less harmful gas in the pouring process, so as to truly realize environmental protection production.
Application of Fused Ceramic Sand Instead of Silica Sand in V-process Casting
V-method casting is a green casting technology with high dimensional accuracy, clear contour and smooth surface. It is not only in line with the national "green manufacturing" industrial policy, but also in line with the benefit needs of enterprises and the product quality needs of customers. It is widely used. V-process casting is all molded with dry sand, such as silicon sand, which emits a lot of silicon dust in the process of sand falling, and the working conditions are very bad, which is an urgent problem to be solved. The use of fused ceramic sand instead of silica sand can greatly reduce the dust emission, which is of great significance to improve working conditions and protect the environment.
Advantages of Fused Ceramic Sand Applied in V-process Casting
1. The refractoriness of fused ceramic sand is higher than that of silica sand at 1800 ℃, and the compactness of filling is high during molding. Therefore, the surface quality of castings can be improved and the scrap rate in production can be reduced;
2. The grain shape of molten ceramic sand is spherical and has good fluidity. For castings with complex shape, it is easy to fill the parts that are difficult to fill, such as internal included angle, deep recess, flat hole, etc. Therefore, the sand inclusion defects in these parts can be significantly reduced, and the workload of cleaning and finishing can be greatly reduced;
3. The amount of molding sand consumed per ton of castings can be greatly reduced, and the waste discharged can be correspondingly reduced;
4. The thermal expansion coefficient of fused ceramic sand is low, which can prevent the expansion defects of castings.
As a green molding material, fused ceramic sand has been widely used, and will play a greater role in the national environmental protection situation and the transformation and upgrading of the foundry industry in the future.