METHOD FOR MAKING CORES AND MOLDS Russian patent published in 2021 - IPC B22C9/02 B22C1/18 

FIELD: foundry.

SUBSTANCE: method for manufacturing casting cores and molds includes filling the technological equipment with a liquid glass mixture, simultaneous or sequential evacuation and heating and holding in the equipment, or simultaneous or sequential evacuation and preheating in the equipment until the rod or mold acquires manipulator strength, removal from the equipment, final heating SHF-oven and exposure to air. Before filling the tooling with a mixture, potassium alum is added to its composition in an amount of 3.0-4.0 wt.%. The content of water glass in the mixture is 2.0-3.0 wt.%. The mixture is heated to 130-140°C, and evacuated to a depth of at least 1.0 bar for 40-60 s. Dehydration of alum during the curing of the core and mold makes it possible to use them as a binder and reduce the content of water glass in the mixture without reducing the technological characteristics and increasing the crumbling of the core and mold.

EFFECT: increased strength properties and their stability, increased gas permeability and knockout of rods and molds, reduced energy consumption and duration of the production cycle of their manufacture.

1 cl, 3 tbl