Abstract: Cores that are inserted into the mold during the die casting of workpieces from metal in order to keep the cavities provided in the workpieces free during the filling of the molds with the melt have to meet demanding requirements with regard to the dimensional stability and suitability thereof for removal from the cavities. Therefore, salt-based cores which can be produced by molding and compressing a core material mixture are provided according to the invention, the core materials thereof being selected from at least one salt, at least one binder system comprising a combination of binder/binding agent and optionally auxiliary substances such as additives, fillers, wetting agents and catalysts, wherein the salt, the binder system and the optionally used auxiliary substances of the core material mixture are inorganic, and these core materials are soluble with water as the solvent.

Abstract: Water-soluble salt cores are used in molds for the production of hollow moldings by plastic molding. The production of hollow plastic moldings is effected by positioning a water-soluble salt core in a mold, molding a thermoplastic molding material around the salt core and, after solidification of the thermoplastic molding material, washing out the salt core with a water-containing solvent.