JPS6142798B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method and apparatus for continuous electroplating of metal strips.

[Prior art]

When electroplating the surface of a metal strip, one of the properties generally desired is that the plating be smooth and have a uniform thickness.

One of the factors to satisfy this property is to keep the interval (distance between electrodes) between the metal strip (cathode) and the plating member (anode) constant.

That is, the weight W of the plating material deposited on the cathode during electroplating follows Faraday's law regarding electrolysis, and if the surface area of the cathode to be plated is A, then the thickness T of the plating is as follows: T=W/( A・d)...d is the specific gravity of the plating layer, and is expressed as follows, so it is proportional to the amount of electricity used and the current efficiency, as shown by the following equation.

T∝I・tE _ffk ...I is the strength of the current, t is the plating time, and E _ffk is the current efficiency at the cathode.

Therefore, it can be seen that when the distance between the electrodes changes, the liquid resistance changes and the current I changes, so that the plating thickness T changes. Therefore, in order to keep the plating thickness constant, it is necessary to keep the distance between the poles constant.

However, in conventional continuous electroplating equipment for metal strips, the plating material, which wears out as plating progresses, is simply placed in a position opposite to the strip metal. There was a problem in that since the distance changed, adjustment work was required to keep this distance constant.

[Purpose of the invention]

An object of the present invention is to provide continuous electroplating in which the plating member is an anode and the plated member is a cathode.
It is an object of the present invention to provide a continuous electroplating method and an apparatus thereof, which make it possible to substantially keep the distance between electrodes constant by reducing changes in the distance between the electrodes due to consumption of the anode during the plating process.

[Summary of the invention]

The present invention provides a method in which a plating member is placed at a predetermined distance from a plated member that is continuously immersed in an electrolyte solution, and the plated member is moved along the plated member. The present invention is characterized in that the plating member is supplied into an electrolyte solution. According to this configuration, the surface of the plating member, which is the anode, is worn out during plating, but a new plating member is supplied by traveling.
The distance between poles can be maintained substantially constant,
As a result, the plating layer to be plated onto the member to be plated can be continuously plated to a substantially uniform thickness.

[Embodiments of the invention]

Embodiments of the present invention will be described with reference to FIGS. 1 to 4.

FIG. 1 shows an embodiment of the present invention, in which a plating member 1 serving as an anode is unwound from an unwinding machine 3 as indicated by an arrow in the figure, and transferred to a plating tank 5. It is introduced and wound up by the winder 4. This plating member 1 has at least its outer surface formed of plating metal. A strip of metal 2 serving as a cathode is introduced into the plating tank 5 from the side opposite to the plating member 1.
The plating member 1 and the strip 2 are respectively supported by a cathode conductor roller 7 to an anode conductor roller 6 disposed in a plating tank 5, and run continuously at a predetermined interval. It's summery. Both conductor rollers 6 and 7 have
A current is applied by a power source 8 so that the supported plating member and strip serve as an anode and a cathode, respectively.

In such a device, electroplating is performed as shown in FIG.

Plating metal ions 1 are continuously introduced into the electrolyte solution from the plating member 1, that is, from the anode side.
0 is dissolved in the solution, and this metal ion 1
0 moves to the strip 2 on the cathode side, and a plating layer 11 is formed on the surface of this strip 2.

Therefore, in this embodiment, since the plating member 1 is supplied so as to run continuously along the strip 2 while maintaining a predetermined interval, the distance between the plating member 1 and the strip 2, i.e. During plating, even if the surface of the plating member 1 is worn out, a new part of the plating member can be continuously supplied, so there is no need to adjust the distance between the poles each time based on the wear of the plating member. The distance can always be maintained constant. As a result, the plating layer 11 applied to the strip 2 can have a uniform thickness over the entire length of the strip.

Furthermore, in this embodiment, since the plating member 1 and the strip 2 are running in the electrolyte,
The flow rate of the electrolyte at the electrode surface increases, and during electrolysis, the layer with low metal ion concentration, that is, the diffusion layer, formed at the electrode interface can be made thinner, thereby increasing the current density. I can do it. That is, by increasing the flow rate of the electrolytic solution, the current density, which is the main factor governing high-speed plating, can be increased, and this has the effect of making high-speed electroplating possible.

It goes without saying that if a plurality of the materials of this embodiment are combined, even higher speed electroplating becomes possible.

Further, although this embodiment shows an example in which the running directions of the plating member and the strip are reversed, the same effect can be obtained even if the plating member and the strip run in the same direction.

Further, in this embodiment, the distance between the poles is kept constant between the conductor rollers, but even if the distance between the poles of the conductor rollers before and after the running direction of the plating member and the member to be plated is slightly different. , it is clear that almost the same effect can be obtained.

Furthermore, although the plating material is supplied continuously in this embodiment, almost the same effect can be obtained even if the plating material is supplied intermittently to the extent that it does not affect plating. is clear.

Further, in this embodiment, as shown in FIG. 2, the plating member 1 serving as the anode is composed of a substrate 11 and a plating metal 12 covering the surface of the substrate, but all the plating members are It may also be made of a metal.

FIG. 3 shows a further improvement of the present invention, which is applied to multi-layer galvanizing of strips (see JP-A-57-26154).

The strip 100 unwound from the payoff reel 103 is guided through an inlet looper 113 and an annealing furnace 114 to a molten zinc bath 115, where it is galvanized. The hot-dip galvanized strip 101 is introduced into a continuous electrogalvanizing apparatus via a cooling tower 116, where it is further electrogalvanized over the hot-dip galvanized layer as shown in detail in FIG. Ru. The hot-dip and electrically double-layer galvanized strip is then passed through a skin pass mill 117, a post-processing device 118, and an exit looper 119.
The coils are wound onto a tension reel 104 through the coils, respectively, to produce a multi-layer galvanized product coil.

In this example, electroplating is performed as shown in FIG.

The hot-dip galvanized strip 101 becomes an anode between two anode-side conductor rollers 108 on the inlet side, and is further formed into a loop by a support roller 109 to change its direction of travel to form a cathode-side conductor roller on the outlet side. A cathode is formed between the rollers 107. That is, the hot-dip galvanized strip 101 serves as a plating member, and zinc metal ions 110 are dissolved in the electrolyte solution from the hot-dip galvanized layer 112 on its surface. Then, the zinc metal ions 110 move to the strip 102 side where the zinc metal ions are dissolved and the hot-dip galvanized layer 112 has become thinner, and then electrogalvanized onto the thinner hot-dip galvanized layer 112. Galvanized again as a coating layer 111. Although the anode and cathode are directly connected by the strip, the strip is looped in a large manner so that the resistance thereof is increased by the support roller 109, so that it has no effect on electroplating.

Generally, the amount of galvanizing applied to one side of the strip by hot-dip galvanizing is 90 to 150 g/m ² , but the thickness of the hot-dip galvanized layer 112 and the electrolytic galvanized layer 111 of the strip that becomes the product is 90 to 150 g/m 2 . If the thickness of the hot-dip galvanized layer on the inlet anode conductor roller 108 is 100, the ratio is as follows from an economical point of view:
Approximately 30 electrogalvanized layers, hot dip galvanized layers
Each is determined to be around 70. This adjustment can be easily made by adjusting the current, time, etc. using Faraday's law regarding electrolysis.

According to this embodiment, the respective characteristics of hot-dip galvanizing and electrolytic galvanizing can be effectively utilized. That is, although hot-dip galvanizing can provide a thick plating layer in a short time, it has the disadvantage that gas is generated from inside when the molten metal solidifies, resulting in pin poles that cause rust. on the other hand,
Although electrogalvanizing provides a good surface finish, it has the disadvantage that the plating process requires a long time and a considerable amount of electricity in order to obtain the desired thickness for corrosion resistance. By combining these two methods as in this example, pinholes, which are a disadvantage of hot-dip plating, can be repaired by electroplating, and the disadvantages of electroplating, such as processing time and amount of electricity, can be Since the plating is sufficiently corrosion resistant, it can be plated in a short time and with a small amount of electricity. Furthermore, in electrogalvanizing,
Continuous hot-dip galvanized strips constitute the anode and cathode, respectively, and the use of upstream hot-dip galvanized strips as the anode eliminates the previously required anode replenishment. There is no need to replenish the anode, such as adjustment work to keep the distance between the electrodes constant when the anode wears out, and the energy used is also reduced compared to the anode (although the distance between the electrodes does not require adjustment). It requires high energy as it is necessary to constantly supply an electrolytic solution between the metal strip and the metal strip at a high flow rate.) It requires only the same amount of energy as conventional electroplating, which saves labor. , has excellent effects in terms of running costs, etc.

In addition, in this example, an example of melting and electric multi-layer galvanizing on only one side was shown, but the same thing as this example was modified in this example so that the other side was multi-layer galvanized. By combining, it is also possible to form a multi-layer galvanized layer on both sides.

〔Effect of the invention〕

According to the present invention, since the plating member is configured to run along the plated member, the distance between the plating member and the plated member, that is, the anode and the cathode, can be adjusted without adjusting the distance between the electrodes. The distance between the electrodes can be maintained substantially constant, and the plating layer to be plated on the plated material can be continuously plated to a substantially uniform thickness. play.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an overview of a continuous plating apparatus which is an embodiment of the present invention, FIG. 2 is an explanatory diagram showing an electroplating pattern in the apparatus of FIG. 1, and FIG.
This figure is an overall configuration diagram showing an outline of a continuous plating apparatus according to another embodiment of the present invention, and FIG. 4 is an explanatory diagram showing an electroplating pattern in the apparatus of FIG. 3. DESCRIPTION OF SYMBOLS 1...Plating member, 2...Member to be plated, 5...Plating tank, 6...Anode side conductor roller, 7...Cathode side conductor roller, 8...Power source.

Claims (1)

[Scope of Claims] 1. A plated member serving as an anode and a plated member serving as a cathode are continuously immersed in an electrolyte solution, and a current is passed between the anode and the cathode to remove the plated member. In a continuous electroplating method in which a film of plating metal is deposited on the surface of a plating member, the plating member is placed along the member to be plated with a predetermined distance between the member and the member to be plated. A continuous electroplating method characterized in that the electrolyte is supplied so as to be able to travel through the electrolyte solution. 2. The continuous electroplating method according to claim 1, wherein the plating member is entirely formed of plating metal. 3. In claim 1, the plating member and the plated member are supplied so that the moving directions of the plating member and the plated member in the electrolyte solution are opposite to each other. A continuous electroplating method characterized by: 4. In claim 1, the plating member is a member in which pre-plated metal is melt-plated, and the plating member forms a loop after traveling along the plating member. A continuous electroplating method characterized in that the running direction of the plating member is changed by changing the running direction of the plating member. 5. The continuous electroplating method according to claim 4, wherein the plating member is a band-shaped metal plated with hot dip galvanization. 6. A plating tank containing an electrolyte solution, a plating member that is immersed in the solution in the plating tank and becomes an anode, and a plating member that is continuously immersed in the solution in the plating tank and becomes a cathode. A continuous electroplating device comprising a member and a device for passing an electric current between the anode and the cathode, wherein the plating member is spaced apart from the member to be plated by a predetermined distance, and A continuous electroplating apparatus characterized in that a traveling device for the plating member is provided so that the plating member can travel in an electrolyte solution along the member. 7. In claim 6, the plating member traveling device includes a device for supplying a plating member and a device for moving the plating member supplied in the electrolyte solution along the member to be plated. A guiding device,
A continuous electroplating apparatus comprising: a device for drawing out the tampering member from the electrolyte solution through the guide device. 8 In claim 7, the device for supplying the plating member is an unwinding device that winds the plating member, and the device for pulling out the plating member is a winding device that winds up the plating member. A continuous electroplating device characterized by: 9. The continuous electroplating apparatus according to claim 7, wherein the device for guiding the plating member comprises a plurality of rollers. 10. The continuous electroplating device according to claim 7, further comprising rollers for supporting the plating member and the member to be plated on the entry side and the exit side of the device for guiding the plating member. . 11 A supply device for supplying metal strips, a device for melt-plating plating metal onto the supplied metal strips, and a plating tank containing an electrolyte solution in which the melt-plated metal strips are continuously immersed. a first guide device for guiding the traveling of the metal strip in the electrolyte solution in the plating tank;
a turning device that forms a loop in the metal strip that has passed through the guiding device and turns the running direction of the metal strip, and a metal strip that has passed through the turning device and is guided by the first guiding device. a second guide device spaced apart from each other and guided so as to be able to run along the metal strip in the electrolyte solution in the plating tank; energizing a winding device and the metal strips so that the metal strips guided by the first guide device become an anode and the metal strips guided by the second guide device become a cathode; A continuous electroplating device comprising: 12. The continuous electroplating apparatus according to claim 11, wherein the first and second guide devices are rollers. 13. The continuous electroplating apparatus according to claim 11, wherein the device for applying current comprises the first and second guide devices and a power source. 14. The continuous electroplating apparatus according to claim 11, wherein the turning device comprises a plurality of rollers. 15. The continuous electroplating apparatus according to claim 11, wherein the apparatus for hot-dipping the metal strip is a hot-dip galvanizing apparatus.