| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an improved method of manufacturing casting molds by which outflow of a binder of RCS (Resin Coated Sand) present in the periphery of aeration openings of a forming mold is prevented, the outflow being prone to occur during aeration with steam, thereby not only resolving problems with the formed mold surface but also advantageously improving separability of the mold during demolding from the forming mold and effectively improving the strength of the obtained mold. <P>SOLUTION: The method of manufacturing casting molds includes (a) a first step for preparing dry-state resin-coated sand that is flowable at room temperature, and is obtained by kneading and mixing preheated molding sand and an aqueous solution of a water-soluble alkaline resole resin, (b) a second step in which, after filling the prepared resin-coated sand into a heated forming mold, the obtained filling phase is aerated at a pressure of 0.1 MPa or less with steam at a temperature of less than 100°C, moistening and cohering the resin-coated sand constituting the filling phase, and (c) a third step for curing the filling phase of the resin-coated sand that has been moistened and cohered. <P>COPYRIGHT: (C)2012,JPO&INPIT |
