Cope/drag interface sealing article for the metal casting industry, and method

Abstract

A fiber-reinforced sealing article disposed between an upper sand mold portion (cope) and lower sand mold portion (drag) to fill in, or correct irregularities in green sand molds. In casting metal shapes in a sand / binder mold, the cope and / or drag mold portions include sand compositions that are not perfectly planar surrounding the mold cavity, leaving one or more areas where the cope and drag are not in contact or otherwise provide a seal surrounding the mold cavity. The fiber-reinforced clay-containing article described herein is disposed between the cope and drag to seal the mold in one or more locations surrounding the mold cavity. The composition described herein is capable of shaping by hand, like modeling clay; and the article is preferably in the form of a continuous rope that is flexible, remains hydrated, and can be cut or broken to a desired length and disposed in area(s) where the cope and drag do not make good mating contact.

Description

FIELD OF THE INVENTION [0001] The present invention is directed to a fiber-reinforced clay-containing article for use in the foundry industry in the casting of molten metal. More particularly, the present invention is directed to an article in the form of a rope, pellet, particle bulk form particularly useful to provide a seal between an upper mold portion (cope) and lower mold portion (drag) to fill in, or correct irregularities in molds, particularly in green sand molds. In casting metal shapes in a sand / binder mold, the cope and / or drag mold portions include sand compositions that are not perfectly planar surrounding the mold cavity, leaving one or more areas where the cope and drag are not in contact, or otherwise do not provide a seal surrounding the mold cavity. The fiber-reinforced clay-containing article described herein is disposed between the cope and drag to seal the mold cavity in one or more locations surrounding the mold cavity. The composition described herein is capa...

AI Technical Summary

Benefits of technology

[0012] Another aspect of the compositions, articles and methods described herein is to provide a sealing composition for the foundry industry useful for minimizing molten metal that flows outside of a mold cavity, said composition comprising clay, water, a hygroscopic agent and reinforcing fibers;

[0015] Still another aspect of the compositions, articles and methods described herein is to provide a sealing article for sealing imperfectly formed mold cavities whereby the sealing article can be reused after metal casting by mixing the used sealing article into a sand composition initially used to form the mold cavity.

Problems solved by technology

When the grains are too close, the molding sand moves and expands causing the castings to show defects such as “buckles” (a deformity in the casting resulting from excessive sand expansion), “rat tails” (a rough, irregular depression that appears on the surface of a casting or a minor buckle), and “scabs” (a breaking away of a portion of the molding sand when hot metal enters the mold).

A major problem with the asphaltic cope rope is that the high temperature of the molten metal will volatilize the volatilizable asphalt components, particularly benzene, leading to EPA violations and hazardous working conditions for foundry personnel.

In casting metal shapes in a sand / binder mold, the cope and / or drag mold portions include sand compositions that are not perfectly planar surrounding the mold cavity, leaving one or more areas where the cope and drag are not in contact or otherwise do not provide a seal surrounding the mold cavity.

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