MANUFACTURING PROCESS FOR PAPER COVERED POWER CABLES IMPREGNATED WITH NONDRIPPING COMPOUND Russian patent published in 1997 - IPC

FIELD: cable manufacture for power transmission. SUBSTANCE: process includes preparation of paper, cooking of impregnating compound incorporating in its composition industrial insulating oil and rosin, covering of cable conductors with paper insulation, drying, impregnation with heated compound in vacuum boiler in two stages: under vacuum and atmospheric pressure, draining of impregnating compound from boiler, cooling down, followed by enclosing cable in sheath, armour, and covering with protective coats. During cooking, impregnating compound is doped with polyethylene wax in the amount of 0.8-30% of total mass of impregnating compound and rosin in the amount of 2-8% of total mass of impregnating compound, and industrial oil - the rest; impregnation process lasts 20-30 h at 120-180 C; vacuum impregnation is made at 5-10 mm Hg until foaming fully ceases; impregnating compound is drained from boiler at temperature higher than melting point of polythene wax. EFFECT: improved operating characteristics of cable and its quality, reduced manufacturing cost and time. 1 dwg