Lost Foam Casting In pouring, in order to drain the gas and mold gasification residue, the sprue should have sufficient height to allow the metal liquid to have enough indenter to promote the stable and rapid filling of the molten metal to ensure that the casting surface is clear and complete. In practice, some enterprises use the original sand casting with the gate cup, due to the smaller size, prone to flow is not smooth lead to the phenomenon of scrap. In order to ensure adequate flow so that the casting process constantly flow, and soon set up the starting pressure head, you can switch to a larger gate cup; sprue made hollow to reduce the air back to spray, increase the pressure when the start pouring head.
Lost Foam Casting uses negative pressure dry sand vibration modeling, using this method modeling shape strength is much greater than the wet sand strength. The method of pumping negative pressure can improve the stability of the mold and timely extract the pyrolysis gasification product produced by the gasification. However, in the production process, some factories only pay attention to observe the table before the table negative pressure, but the casting process often overlooked negative pressure changes, resulting in casting defects. This problem can be solved well by taking a method of adjusting the negative pressure during the casting process according to the size of the casting and the amount of pyrolysis products.