VERFAHREN ZUR HERSTELLUNG VON KERAMISCHEN SCHALEN ALS GIESSFORM

摘要

The invention relates to a process for producing ceramic chills as casting moulds in which: a) a fusible or removable pattern of a part to be cast is made; b) the pattern is immersed in a dipping consisting of a slurry of a fireproof material and a binder containing a colloidal, aqueous silica sol and polymers in order to form a damp coating on the pattern; c) a coarse, fireproof powder is sprinkled thereon; d) the coating is dried; e) steps b), c) and d) are repeated until the chill is of the desired thickness. To produce fast-drying dip coatings with a drying time comparable to that of chills made on the basis of alcoholic binders, the dipping compound contains a dispersion of aqueous colloidal silica sol as a binder to which are added synthetic high polymers and/or an emulsion from the group of silicon-organic compounds to give a coating which, after drying, is waterproof but water-vapour-permeable.