RU2155247C2 - Apparatus for applying coats on metals - Google Patents

Abstract

FIELD: coat applying apparatus. SUBSTANCE: proposed apparatus includes bath for applying coats on material which is mounted between rolling and unrolling units. Fixed anode and revolving drum-cathode are located in bath. Current lead running to drum-cathode is made in form of hollow body with opening for shaft; it is separated from bath. Body is filled with molten metal and insulator located above metal. Level of molten metal is below opening in body for shaft of drum-cathode. Insulator is liquid; its density is lesser than density of molten metal. EFFECT: enhanced reliability due to avoidance of formation of oxides of molten metal and its spontaneous leakage from body of current lead. 3 cl, 3 dwg

Description

 The invention relates to the field of hydrometallurgy and can be used in the coating of a metal strip by electrolysis.

 A device is known for coating copper foil, comprising a housing, inside of which a rotating drum-cathode is mounted, a fixed anode, and between them there is a liquid electrolyte with components for the desired coating formed under the influence of electric current. The supply unit for transmitting voltage to the drum-cathode is made in the form of two bushings connected to the shaft of the drum-cathode (see TU N 48-2-3-86, 1986 drawing N 2695. 06.01.000 SB).

 The disadvantage of this type of device is that there are large losses of electricity in the node of its transmission to the shaft. In addition, there is an overheat of the current supply transmission unit and its quick failure. Another disadvantage of this device is the complex construction of the transmission unit itself and inconvenient when replacing, requiring the unpressing of the bushings from the shaft.

 Also known is a device for applying a plating to a metal strip containing a housing with a bath, inside of which there is a fixed anode and a drum-cathode rotating on a shaft around its axis with a current-supply unit for the drum-cathode in the form of brushes and rings (see French patent N 2438692 Cl. C 25 D 1/04, 1980).

 The disadvantage of this device is its short service life due to overheating and destruction during operation, as well as significant losses of electricity, which makes the entire device unreliable during operation and it is impossible to obtain high-quality coating on it due to significant voltage drops at different time intervals.

 The technical task of the proposed device is to reduce energy losses during the coating process, increase reliability and increase the service life during operation.

 This task is achieved in that the apparatus for coating, containing a bath for coating a material with a fixed anode placed therein and a drum-cathode rotating on the shaft and a current supply to the drum-cathode through the shaft, is additionally equipped with material winding and winding units, between which a bath, and the current lead is made in the form of a hollow body with a hole for the shaft of the drum-cathode, separated from the bath, in which liquid metal and an insulator located above the metal are located, while the metal level in the body cavity and it is located below the hole under the shaft of the drum-cathode, the insulator is made liquid, and its density is less than the density of the liquid metal.

 In FIG. 1 shows a General diagram of the apparatus of the coating of the proposed design.

 In FIG. 2 is a section along AA in FIG. 1 in the form of a specific structural design.

 In FIG. 3 is a section along BB in FIG. 2.

 As shown in the drawings, the apparatus of the invention comprises a winding assembly 1 with a belt speed adjuster 2, a washing bath 3, a coating bath 4, a drying chamber 5 and a winding assembly 6. Each of the coating baths 4 has a rotating drum cathode 7 and a fixed anode 8. In the baths 4, between the cathode 7 and the anode 8, an electrolyte 9 is filled in. A drum-cathode 7 is mounted on the shaft 10 and the supports 11, on the side of which an insulated housing 12 with a cavity 13 is installed. In the cavity 13 of the housing 12, the metal 14 and the insulator 15. The shaft pulley 16 10 is located inside the cavity 13. The level 17 of the metal 14 is located below the lower edge of the hole 18 of the shaft 10. The cavity 13 closed by a cover 19, a current supply is formed as a fixed bus 20. The housing 12 is isolated from the bath 4 plate 21.

The work of the proposed device is as follows. The roll of coated material is installed in the winding assembly. Then the end of the tape of material is passed through the bath (washing 3, coating 4), drying 5 and fixed in the winding unit 6. After that, voltage is applied through the tires 20, which is transmitted through the molten metal 14 to the pulley 16, and then through the shaft 10 to the drum cathode 7. Simultaneously with the voltage supply, the winding device drives are turned on and the tape moves. Under the influence of electric current in the baths of the coating 4, a coating is applied to the tape. As a current lead placed in the cavity 13, a metal with a low melting point (about 0 ^° C.) is used, for example indium, galium, etc. The housing 12 is provided with a lid 19, which closes the cavity 13 from contaminants entering it, and a liquid insulator 15, for example, a glycerol solution inert to air, is located above the metal 14. By setting a certain speed of the material inside the bath, the desired coating thickness is achieved. This process continues until the entire roll of material passes through the coating baths 4. After this, the power supply is stopped, the roll is removed from the winding unit 6, and a new roll is installed in the winding unit and the process is repeated.

 By equipping the cavity of the current supply housing with an insulator, it is possible to exclude the contact of liquid metal with oxygen in the air, to exclude its hardening and the formation of an oxide film. In addition, the location of the level of liquid metal below (at the level) of the lower edge of the hole in the housing under the shaft eliminates the leakage of the latter from the cavity due to its winding on the shaft during rotation, with a thin layer and passage through the seal of the hole due to the significant adhesion to the shaft.

 The use of the invention in devices for applying protective films by the electrolytic method can improve the reliability of the device, reduce the consumption of current-carrying material and improve the quality of the resulting coating due to the stability of the current supply to the drum throughout the entire coating process in comparison with the known ones.

Claims (3)

 1. The apparatus for coating, containing a bath for coating a material with a fixed anode and a rotating drum cathode placed in it together with a shaft and a current supply to the drum cathode, characterized in that it is equipped with material winding and winding units, between which is installed coating bath, current supply is made in the form of a hollow body with a hole for the drum-cathode shaft, separated from the bath, with liquid metal placed inside the body and an insulator located above the liquid metal, while the liquid metal level is located below the hole in the housing under the shaft of the drum-cathode.  2. The apparatus according to claim 1, characterized in that the insulator is made liquid.  3. The apparatus according to claims 1 and 2, characterized in that the density of the material of the insulator is less than the density of liquid metal.

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