Patent ID: 8490677
Filing Date: 2013-07-23
Classification: B22C

Abstract:
1. A method for forming molds comprising: (a) foaming an aggregate material mixture by stirring the aggregate material mixture containing granular aggregate materials, 0.1-5.0 parts of one or more kinds of aqueous binders per 100 weight parts of the granular aggregate materials, a cross linking agent which induces a cross linking reaction with the aqueous binders in an amount of at least 5 weight % in relation to the aqueous binders, and water, wherein the stirred mixture has a ratio of foaming of 50-80%, the ratio of foaming being defined by: (b) filling the foamed aggregate material mixture under pressure in a space for forming molds; (c) together with caking the aggregate material mixture by evaporating the water in the filled aggregate material mixture under heat and forming a mold; carrying out a cross linking reaction of the aqueous binders and the cross linking agent; and (d) taking out the formed mold from the space for forming molds, wherein the aqueous binders are selected from the group consisting of the combination of polyvinyl alcohol or its derivatives and starch or its derivatives, the combination of saponins and starch or its derivatives, and the combination of polyvinyl alcohol or its derivatives, and other saccharides.