During pouring in lost foam casting, in order to evacuate gases and residues from pattern vaporization, the sprue must have sufficient height to provide enough metal head pressure to drive the molten metal flow steadily and quickly fill the mold, ensuring a complete and clear casting surface. In practice, some enterprises use the same pouring cups as those used in green sand casting. Due to their small size, this can easily cause unstable metal flow, leading to scrap. To ensure sufficient flow rate to maintain a continuous pouring process and quickly establish dynamic head pressure, larger pouring cups can be adopted. The sprue can also be made hollow to reduce back-gassing and increase the initial pouring head pressure.

Lost foam casting uses negative pressure dry sand with vibration molding. With this method, the mold strength is much greater than that of green sand molds. The application of negative pressure can improve mold stability and promptly remove the pyrolysis products generated during pattern vaporization. However, in production, some factories only pay attention to the pre-pour negative pressure reading and often neglect changes in negative pressure during pouring, resulting in casting defects. This problem can be well solved by adjusting the negative pressure during pouring according to the casting size and the amount of pyrolysis products. Due to its low equipment investment and low cost, lost foam casting technology has developed rapidly in recent years. Many existing small and medium-sized foundries are increasingly adopting this technology. However, some enterprises fail to pay sufficient attention to certain operational details, such as patterns, coatings, vibration methods, and pouring procedures, leading to unstable casting quality during production.

As a near-net-shape forming method, lost foam casting technology has developed rapidly in recent years. Overseas, with the successive completion and commissioning of mechanized and automated lost foam casting production lines, as well as the significant economic and social benefits they have generated, lost foam casting technology has demonstrated strong vitality.

Although the application of lost foam casting technology in China progressed slowly in the earlier period, it has developed rapidly in recent years. Especially due to the low equipment investment and short process route, many existing small and medium-sized foundries are increasingly adopting this technology. However, some enterprises have failed to pay adequate attention to certain operational issues, resulting in some problems during production that have greatly affected casting quality.