COOLING METHOD OF COOLING CAN

PURPOSE:To cool effectively a can with a less refrigerant in the stage of cooling a cylindrical can for transferring a high polymer film on the surface of which a thin film of a ferromagnetic metal is to be deposited by evaporation by evacuating the inside of the can and evaporating the refrigerant with the inside wall surface. CONSTITUTION:While a high polymer film 3 of polyester, etc. is transferred by a cylindrical cooling can 4 under rotation in a vacuum vessel 1, a film deposited by evaporation is formed on the surface of said film by vapor flow 9 of the ferromagnetic metal in a crucible 7 by electron rays 6. The inside of the can 4 is evacuated in this case and a refrigerant such as water is evaporated under reduced pressure from the fine holes 15 on the inside surface of a water pipe 14 installed zigzag on the inside circumferential surface. The can 4 is effectively cooled by the heat of vaporization in such evaporation by which the can 4 and the film 3 in contact therewith are cooled with the smaller amt. of the refrigerant. The thin film of the ferromagnetic metal is thus stably deposited by evaporotion on the film 3 to a uniform thickness.