METHOD FOR MANUFACTURING CERAMIC CONSTRUCTIONAL PRODUCTS Russian patent published in 1994 - IPC

FIELD: manufacture of constructional items. SUBSTANCE: desired ceramic constructional products are manufactured by method of plastic molding involving nonisometric granules in which ratio between surface area (sq. mm) and volume (cu. mm) is 0.6 to 2.1. Mold is filled with burnt granules, surfaces of granules are wetted by immersing mold into clay slicker or water or by passing steam through mold, granules are compacted to depth of surface layer of 0.3 to 20 mm either prior to withdrawing semi-finished product from mold or during heat treatment after pyroplastic condition is attained by hot molding at pressure of 0.3 to 20 MPa. Granule molding may be accompanied by electroosmosis. Disclosed method prescribes using method of vibration or remolding or ramming when embedding granules. Product is heat-treated by allowing hot gases to pass through highly gas-permeable workpiece or using high-frequency current or both. It is admissible that pigments or glaze be applied to compacted surface. Finished products have open porosity between 2 to 48 % , compressive strength of 5 to 50 MPa and frost resistance of more than 50 cycles. EFFECT: more sophisticated technique. 4 cl