Abstract: A method of removing a core from a molded product in which the core is formed of a particulate inert material, such as sand, bound together by a cured water soluble binder. The binder is cured by heat. The core and molded product are exposed to water, preferably heated water in a bath or steam, after the product has been molded to rapidly disintegrate the core and remove it from the molded product.

Abstract: A method of removing a core from a molded product in which the core is formed of a particulate inert material, such as sand, bound together by a cured binder of a water soluble carbohydrate alone or mixed with a silicate is disclosed. The silicate is preferably an alkali earth metal silicate, preferably sodium silicate, and the carbohydrate is preferably a saccharide or starch. The binder is cured by heat. The core and molded product are exposed to water, preferably heated water in a bath or steam, to rapidly disintegrate the core and remove it from the molded product.

Abstract: A method of removing a core from a molded product in which the core is formed of a particulate inert material, such as sand, bound together by a cured binder of a water soluble carbohydrate alone or mixed with a silicate is disclosed. The silicate is preferably an alkali earth metal silicate, preferably sodium silicate, and the carbohydrate is preferably a saccharide or starch. The binder is cured by heat. The core and molded product are exposed to water, preferably heated water in a bath or steam, to rapidly disintegrate the core and remove it from the molded product.

Abstract: The utility of a cover for vents or drains is improved by having a unitary, integral fastening means which can be used to either secure the covering so securely that mutilation of the cover may be required to remove the cover or that the cover may be easily removed and replaced. The cover can be formed from any polymer with any desired surface configuration, i.e., hole size and shape, and can be used to modify existing covers or as the original cover for a hole or vent. The fastening means when integral is made of the same material as the cover and can be easily expanded and secured by pressure elements. Since the normal sleeve has been replaced by the integral fastener which is part of the cover, no relative rotation of the sleeve and pressure means can occur.

Abstract: A method of removing a core from a molded product in which the core is formed of a particulate inert material, such as .[.sand-bound.]. .Iadd.sand, bound .Iaddend.together by a cured binder of a water soluble carbohydrate alone or mixed with a silicate is disclosed. The silicate is preferably an alkali earth metal silicate, preferably sodium silicate, and the carbohydrate is preferably a saccharide or starch. The binder is cured by heat. The core and molded product are exposed to water, preferably heated water in a bath or steam, to rapidly disintegrate the core and remove it from the molded product.