Abstract: The invention relates to a molding material mixture for production of casting molds for metalworking, to a process for producing casting molds, to casting molds obtained by the process and to the use thereof. For the production of casting molds, a refractory molding matrix and a waterglass-based binder are used. The binder has been admixed with a proportion of a particulate metal oxide which is selected from the group of silicon dioxide, aluminum oxide, titanium oxide and zinc oxide, particular preference being given to using synthetic amorphous silicon dioxide. The molding material mixture comprises a carbohydrate as a further essential constituent. The addition of carbohydrates allows the mechanical strength of casting molds and the surface quality of the casting to be improved.

Abstract: For production of a hollow structural part made of fiber-reinforced plastic, a water-dispersible support core made of a water-soluble binding agent consisting at least partly of a water-soluble silicate-containing binding agent, and a filler is wrapped with the reinforcing fibers. The fibers on the support core are impregnated with a curable plastic, the plastic is cured, and the support core is subsequently flushed out with water.