Working principle of lost foam casting technology in foundry production

Lost foam casting technology is usually referred to as lost foam casting in English, which is also called as lost foam casting or lost foam casting in the industry. The basic principle of the process is to combine the wax model or foam model similar to the size and shape of the preformed casting into a model cluster, then brush the refractory coating on the outer surface of the cluster, then heat it and then dry it, then bury it in dry quartz sand to form the shape, and then pour it under negative pressure to make the preset model fast gasification, and the high temperature liquid metal occupies the prefabricated model position. The casting is formed after high temperature liquid solidifies and cools, which is a new casting method.

Lost foam casting is a new casting method with high forming rate, small machining allowance and accurate blank forming. The advantage of this new casting method is that it doesn’t need to take the prefabricated sample mold out of the mold cavity. At the same time, the parting line can’t be seen in the product appearance, and there is no need to use sand core in the process of lost foam casting There are no burr, burr, draft angle and other casting defects on the formed products, and the size deviation caused by the combination of core and sub box can be reduced.

After the completion of casting, machining allowance can be reduced to 1.5mm to 2mm. Due to the reduction of machining allowance, the cost related to the subsequent processing consumption of mechanical manufacturing can be reduced. Compared with the traditional sand casting method, the machining amount can be greatly reduced by 40% to 50% by using EPC Process. This technology was first invented by H.F. Shroyer of the United States in 1958, and then continuously improved through scientific research of relevant technical personnel in Germany, Japan and Italy. After the 1980s, this technology has developed rapidly in the world.

In the 1980s, China also introduced lost foam casting technology. In recent years, the rapid development of lost foam casting technology in China, the development results are very optimistic. A foundry machinery factory in Kunming, Yunnan Province of China has done a good job in the field of lost foam R & D, and its products have been exported to Malaysia and other surrounding countries. In addition, Tsinghua University, Huazhong University of science and technology and other institutions of higher learning have made valuable contributions to the research and development of lost foam casting technology.