Lost foam casting technology process

The process flow of lost foam casting is divided into white area and black area.

(1) The process of lost foam casting white area: the white area is mainly a program for making foam models. Foam forming process should first consider the wall thickness and material of lost foam Castings, and choose the foaming agent (original foaming beads) suitable for it. After finding the appropriate foaming beads, put the original beads into the intermittent hair dryer for foaming. Consider the process requirements during foaming, such as density, strength and other indicators. After drying in the curing bed of the pre hair machine, it is transported to the curing bin for curing. Then enter the molding workshop, inject the matured beads into the lost foam casting mold of the preform, expand and melt the beads after steam heating and humidification, and finally fill the cavity of the lost foam casting mold to form the shape of lost foam casting. Then, after cooling through the water cooling process, the foamed white lost foam casting mold has a certain strength. Then enter the drying room for drying, and the white mold is made.

(2) Lost foam casting black area process flow: the lost foam casting plant places the special interlayer sand box on the vibrating equipment table, then paves the dry quartz sand with a thickness of about 100mm at the bottom of the box (the particle size of quartz sand is about 20-40 mesh), then vibrates the quartz sand in the box through the vibrating equipment, and scrapes the top of the box at the same time. Then, the Yellow mold made in the white area is pre placed on the bottom sand surface of the lost foam casting sand box, and the position of the Yellow mold in the lost foam casting sand box is arranged according to the pre design, then the sprue reserved model used during casting is connected with the pouring riser, and then the lost foam casting sand box is filled with dry sand, and then the lost foam casting sand box is vibrated again according to the process requirements, After vibrating the sand in the lost foam casting sand box, scrape the dry quartz sand at the box mouth again. After scraping, cover the gate with plastic film, then place the gate cup at the gate, and fix the plastic film at the edge of the box with quartz sand. Then connect the vacuum system hose to the pipeline at the bottom of the box, start the equipment of the vacuum system for vacuum pumping, and fasten the dry sand in the box after meeting the process time and process requirements, so that the manufacturing process of lost foam casting mold in the black mold area is completed. Wait for the metal solution to enter the Yellow mold cavity of the mold box through the gate cup, and then wait for the white mold gasification to disappear. The high-temperature metal solution quickly replaces the position of the white mold cavity and overflows out of the gate, and then the pouring procedure is completed. After pouring, the box body shall be cooled by pressure maintaining. After cooling, reset the vacuum equipment, cancel the vacuum pumping process of lost foam casting box body, and finally turn over the box after cooling the lost foam casting to take out the lost foam casting.