The disadvantage of vacuum casting iron plate is that compared with traditional sand casting, the manufacturing cost is higher, and this increase of cost can be offset by the added value of the product. Therefore, compared with the traditional sand casting process, there are still many advantages of vacuum casting cast iron plates, summarized as follows:
1. The dimensional accuracy of the vacuum casting iron plate is high. The surface of the cast iron plate is smooth, with clear outline and accurate size. The surface of the mold cavity is covered with plastic film, and finer dry sand is used to make the mold hardness high and uniform, and the mold surface is smooth and flawless. What's more, the sand box is easy to mold, and the cavity is not easy to deform. During pouring, since the sand box is kept in a vacuum state, it is beneficial to fill the cavity with molten metal.
2. The vacuum casting iron plate has a small machining allowance and a high utilization rate. So it can save related adhesives, additives and sand mixing equipment. Because the cooling rate of molten metal in the cavity is slow, the metal mobility is better, and the filling capacity is strong, which is beneficial to the replenishment of the metal and improves the utilization rate of the metal. The mold has high hardness and slow cooling, so it can get the use of feeder to reduce the riser and the machining allowance to guarantee the long service life of the mold and sand box.
3. Various operation and maintenance costs are reduced and investment is saved. Except for the need to add a vacuum pump and a special sand box, other equipment is relatively simple. Because vacuum casting machine uses dry sand, and it is easy to shake off the sand, which can save the sand shaker, sand mixer and some auxiliary equipment, so the investment cost is low, and the equipment maintenance is convenient. What's more, the raw materials and labor are saved to keep the high rate of sand recovery rate.
4. The service life of the tool is effectively extended. Because the vacuum cast iron plate is protected by a plastic film, the drafting force is very small. There is only slight vibration and is not affected by high temperature and high pressure, so the appearance is not easy to deform and damage.