JPH10251893A - Electroplating method for metallic strip and electrolytic cell for metallic strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the adhesion property of a plating metal and a metallic strip by an anodic treatment prior to a plating treatment at the time of electroplating the metal on the metallic strip subjected to the activation treatment by degreasing, washing and pickling. SOLUTION: The metallic strip S previously subjected to degreasing and washing is subjected to the activation of the surfaces by the pickling treatment and is washed again. At the time of transporting the metallic strip S by means of rolls 2a, 2, 2b and electroplating the metal on the surfaces by passing the strip in a plating cell 1, the metallic strip S is first passed through an inlet side pass section 8 and is subjected to the anodic treatment by supplying the current between the strip as an anode and an electrode 3 as a cathode, by which the surfaces of the metallic strip S are reactivated. In succession, the metallic strip S is passed through an outlet side pass section 9 and the metal is electroplated on the surfaces of the metallic strip S by supplying the current between the roll 2b as the cathode and the electrode 3 facing the roll as the anode. The plating layers having the excellent adhesion property to the metallic strip are thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for electroplating tin or chromium on the surface of a metal strip.

[0002]

2. Description of the Related Art FIG. 7 is a line diagram of a conventional metal strip continuous electroplating. As a method of continuously electroplating a metal such as tin, chromium, zinc or the like on the surface of a metal strip, a method before electroplating is performed. As a preliminary treatment, the surface of the metal strip is washed in a degreasing process to remove foreign substances and adhered oils and fats, the surface of the metal strip is activated in an acid washing process, and after cleaning, the metal strip is subjected to electrolytic plating in an electrolytic plating process. I do.

FIG. 6 is a schematic view of a conventional metal strip electrolytic cell. The electrolytic cell 1 is divided into a plurality of tanks 1a. Each tank 1a has a roll 2a at an upper part and a lower part for transferring a metal strip S. , 2b, 2 are arranged, and the upper rolls 2a, 2b are energizing rolls 2a, 2b for electrically connecting the metal strip S to a DC power supply. Electrodes 3 made of lead or a lead alloy are arranged on both sides of the metal strip S in the electrolytic plating solution. The negative pole of the DC power supply 4 is connected to each tank 1 for electrolytic plating.
The positive poles are connected to the electrodes in the electrolytic plating solution, respectively, on the upper conductive rolls 2a and 2b.

[0004]

However, if the activation of the strip surface is not sufficient even after the conventional pre-treatment of degreasing and pickling, or depending on the material of the metal strip, it may take a while to perform the plating from pickling to electrolytic plating. In the case where the surface of the metal strip is easily deactivated, sufficient plating quality may not be obtained even if electrolytic plating is performed after the pretreatment because adhesion of plating cannot be obtained. In addition, due to strict plating quality, it is necessary to improve the plating quality.

SUMMARY OF THE INVENTION The present invention provides a method for electroplating a metal strip and a metal strip electrolytic cell capable of obtaining sufficient plating quality.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a metal strip which has been pickled and washed is first placed in an electrolytic cell provided with an anodizing section and an electrolytic plating section, and the metal strip is first anodized in the anodizing section. Then, the surface of the metal strip is reactivated by anodizing, followed by electrolytic plating using the metal strip as a cathode in an electrolytic plating section.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of the electrolytic treatment of a metal strip according to the present invention. An electrolytic cell 1 is divided into a plurality of tanks 1a, and each tank 1a has an upper portion for transporting a metal strip S. Rolls 2a, 2b, 2 are arranged at the bottom and at the bottom, respectively. Rolls 2a, 2b at the top are energized rolls 2 for electrically connecting the metal strip S to a DC power supply.
a and 2b. Electrodes 3 made of lead or a lead alloy are arranged on both sides of the metal strip S in the electrolytic plating solution.

In the present invention, first, anodic electrolysis is performed in the anodizing section of the entrance path of the electrolytic cell 1 to reactivate the surface of the metal strip, and subsequently, electrolytic plating is performed in the electroplating section. The positive electrode of the DC power supply is connected to the energizing roll 2a, that is, the metal strip S, on the upper part of the tank 1a of the input path 8 for performing anodic electrolysis, and the negative electrode is connected to the electrode 3 in the electrolytic plating solution. After passing through, the electrolytic plating is performed in the exit path 9, so that the upper energizing roll 2b is connected to the negative pole of the DC power supply 4, and the electrode in the electrolytic plating solution is connected to the positive pole.

FIG. 2 is a schematic view of a metal strip electrolyzer according to the present invention. In the electrolyzer 1, rolls 2a and 2a are provided at the upper and lower portions of a tank 1a for transporting the metal strip S, respectively.
2b and 2 are arranged, and the upper roll is made of a metal strip S
Rolls 2a,
2b. The electrodes 3 are arranged on both sides of the strip S in the electrolytic solution. As the electrode material, for example, lead or a lead alloy is used.

Further, in this embodiment, a vertical partition plate 5 made of an insulating material is provided between each metal strip S of an entrance path serving as an anodizing section and an output path serving as an electrolytic plating section, and a vertical partition plate 5 is provided. At the lower part of the partition plate 5, a horizontal partition plate 7 having a gap 6 through which the metal strip S passes is provided, and the tank 1a is provided with an inlet pass portion 8 serving as an anodizing portion and an outlet pass portion 9 serving as an electrolytic plating portion. By partitioning, the electrical resistance between the entrance-side path section 8 and the exit-side path section 9 is increased, and the influence of the entrance-side path section 8 and the exit-side path section 9 on each other is reduced.

In order to perform anodizing in the inlet pass section 8, the upper energizing roll 2 a is connected to the positive pole of a DC power supply, the electrode 3 in the electrolytic plating solution is connected to the negative pole, and in the outlet pass section 9. Since the electrolytic plating is performed, the current-carrying roll 2b
Is connected to the negative pole of the DC power supply 4, and the electrode in the electrolytic plating solution is connected to the positive pole.

In the above arrangement, the metal strip is anodized by using an electrolytic plating solution with the metal strip as an anode to reactivate the surface of the metal strip. Electroplating is performed in the activated state, so that the adhesion between the metal strip and the plated metal is improved.

FIG. 3 is a schematic view of another embodiment of the electrolytic cell according to the present invention. The entrance-side pass portion 8 and the exit-side pass portion 9 are communicated with each other through a lower tank 10 on which a transport roll 2 is disposed. The electrodes 3 are arranged on the entrance-side path portion 8 and the exit-side path portion 9 with the strip S interposed therebetween, and the electrodes 3 of the path portions 8 and 9 are arranged independently of each other. Influence can be reduced.

FIG. 4 is a schematic view of another embodiment of the electrolytic cell of the present invention, in which the inlet-side pass portion 8 and the outlet-side pass portion 9 are made independent, and each of the pass portions 8 and 9 has a squeezing roll 11 at a lower portion. At the same time, the electrodes 3 are arranged with the strip S interposed therebetween. Each pass unit 8,
At the lower part of 9, a transport roll 2 is arranged,
A receiving tank 12 for the leaked liquid is arranged. Since the path units 8 and 9 are completely independent, the path units 8 and 9 hardly influence each other electrically.

FIG. 5 is a schematic view showing an embodiment in which the present invention is applied to a horizontal electrolytic cell. The anodizing section 8 has an energizing roll 2a on the metal strip entry side of the electrolytic cell 1 as a positive pole and an electrode 3 as a negative pole. Which is connected to the metal strip S
The anodizing section 9 is formed by setting the current-carrying roll 2b on the exit side to a negative pole and the electrode 3 to a positive pole to form a metal strip passing through each processing section from a liquid supply nozzle 13 provided above and below the metal strip S. S is supplied with an electroplating solution, and the metal strip S is first anodized in the anodizing section to perform anodization to reactivate the metal strip surface.
Subsequently, electrolytic plating is performed using the metal strip S as a cathode in an electrolytic plating section.

[0016]

According to the present invention, since the electroplating is immediately performed in a state where the surface of the metal strip is activated, the adhesion between the metal strip and the plating metal can be sufficiently ensured, and the plating quality can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an electrolytic treatment of a metal strip of the present invention.

FIG. 2 is a schematic view of a metal strip electrolytic cell of the present invention.

FIG. 3 is a schematic view of another embodiment of the electrolytic cell of the present invention.

FIG. 4 is a schematic view of another embodiment of the electrolytic cell of the present invention.

FIG. 5 is a schematic view showing an embodiment in which the present invention is applied to a horizontal electrolytic cell.

FIG. 6 is a schematic view of a conventional metal strip electrolytic cell.

FIG. 7 is a line diagram of a conventional metal strip continuous electrolytic plating.

[Explanation of symbols]

 S Metal strip 1 Electrolyzer 1a Tank 2 Roll 2a, 2b Roll (Electrified roll) 3 Electrode 4 DC power supply 5 Vertical partition plate 6 Gap 7 Horizontal partition plate 8 Inlet path part (anodic treatment part) 9 Outlet path part (electrolysis) Plating section) 10 Lower tank 11 Squeeze roll 12 Receiving tank 13 Liquid supply nozzle

Claims (5)

[Claims] 1. An anodizing treatment is performed on an acid-washed and cleaned metal strip in an electrolytic bath provided with an anodizing section and an electroplating section. After reactivating the surface,
A method for electrolytic plating a metal strip, wherein the electrolytic plating is performed using the metal strip as a cathode in an electrolytic plating section. 2. An electrolyzer for a metal strip, comprising: an anodizing section provided on the entry side of a metal strip; and an electroplating section connected to the anodizing section. 3. An electrolytic cell comprising an entrance pass section serving as an anodizing section on the entry side of the metal strip and an exit pass section serving as an electrolytic plating section on the exit side of the metal strip. A DC power source is electrically connected to the electrode, the energizing roll on the input side, and the energizing roll on the outgoing side, respectively, with a polarity for anodizing and electrolytic plating. 3. The metal strip electrolytic cell according to 2. 4. An inflow path and an outflow path are communicated by a lower tank provided with a transport roll, and electrodes are arranged at positions sandwiching the strip between the paths. The metal strip electrolytic cell according to claim 2 or 3, wherein 5. An electrolytic cell comprising an independent inlet pass section and an independent outlet pass section. A narrowing roll is provided at a lower portion of each pass section, and an electrode is arranged with a metal strip interposed therebetween. 5. The metal strip electrolytic cell according to claim 2, wherein a roll is disposed.