In resin sand molding and water glass sand molding, although the molding strength of both is very high, sand inclusion and blisters will also occur in castings.
Reason: The sand cleaning in the sand mold is not clean, and there are residual sand and gravel. In the process of pouring, it is caused by the molten iron scouring the sand of the runner wall.
Some manufacturers use paint to prevent it and get better results, but there will still be sand inclusions and blisters in the castings. One is that it is more laborious and difficult to paint the gate. The second is that the pouring temperature is high during the pouring process, the scouring is large, and the paint is easy to fall off under the scouring and high-temperature immersion. Causes sand holes. For a long time, many foundries have not paid much attention to the runner. The scouring of the runner wall during the pouring process is ignored. As a result, sand holes in the castings are caused.
method:
1. Improve the yield of castings, improve the quality of castings, and reduce the total cost of castings.
2. Using cast gate ceramic tube, this product is easy to use, has the characteristics of smooth flow, resistance to molten iron, molten steel erosion, no absorption of molten steel, good saw ability, etc. It can simplify the modeling process and save the difficult work of coating the inside of the gate. , and to improve the layout of the gating system to avoid casting sand flushing, sand holes, and sand addition defects. It plays a great role in improving the quality of castings and the yield of castings, especially in various self-hardening casting shapes, with more prominent features.