JPS59185797A - Continuous electroplating device provided with soluble electrode - Google Patents

Abstract

PURPOSE:To assure a uniformly high flow rate over the entire part of a plating cell by using soluble electrodes in electroplating, providing countercurrent discharging nozzles for an electrolyte in two stages and providing a variable dam seal with an adjustable flow rate in the end part on the inlet side. CONSTITUTION:Soluble electrodes 2 are specially disposed on both sides of a strip 1 which travels continuously in an arrow direction, with said strip as a center. Respectively a pair of counter current discharging nozzles 4 for an electrolyte are disposed in the end part on the strip outlet side of a plating cell 3 so that the electrolyte is discharged uniformly in the transverse direction of the strip 1. A variable type dam seal 5 constituting an outflow device for the electrolyte which can adjust freely flow rate is provided in the end part on the inlet side of the strip 1 in the plating cell 3 and dam rolls 6 for preventing the leakage of the electrolyte are provided. The plating having high quality is efficiently carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous electroplating device with soluble electrodes, and in particular to a device for applying zinc plating or zinc-based alloy plating to continuously running strips.

Conventionally, in order to perform zinc plating or zinc-based alloy plating, an apparatus using a soluble electrode or an insoluble electrode is used as an electrode. Here, as a device using soluble electrodes, a strip is continuously run between a pair of soluble electrodes installed horizontally and spaced apart, and an electrolyte is applied from an electrolyte discharge nozzle to the upper and lower surfaces of the strip. There is a so-called horizontal tank system that is configured to discharge in a direction perpendicular to the traveling direction. However, in such a conventional horizontal tank system, the electrolyte flow rate has a widthwise distribution, and the dissolution rate of the anode on the electrolyte discharge side where the flow rate is high is thicker than that on the opposite side (and therefore , the dissolution of the anode becomes uneven in the width direction.In addition, on the opposite side of the electrolyte discharge side, the flow collides with the tank wall and vortices are likely to be generated, resulting in uneven plating or the entrainment of foreign matter. This will have a negative effect on plating quality.

Furthermore, recently proposed continuous electroplating devices include a so-called jet cell method in which an electrolytic solution is blown in a countercurrent to the running strip from the end of the strip exit side of the plating tank or the center of the strip.

In this method, an insoluble electrode is used as the electrode, and a completely sealed tank is utilized. Compared to the horizontal tank method described above, this method has the advantage that the relative flow velocity between the electrolyte and the strip can be increased, and high-quality plating can be performed efficiently. However, when implementing this method using a soluble electrode, a closed tank cannot be used as it is necessary to provide a replenishment mechanism for the molten electrode. The flow velocity near the strip inlet of the electrolytic cell becomes low. Since the rate of reduction in flow rate is large as described above, the length of the plating tank cannot be increased in order to ensure a high flow rate throughout the entire plating tank, resulting in a method with poor equipment efficiency.

An object of the present invention is to provide an open-type continuous electroplating device using soluble electrodes that eliminates the drawbacks of the prior art.

Here, the present invention uses a soluble electrode, provides at least two stages of countercurrent discharge nozzles for the electrolytic solution, and further provides an electrolytic solution outflow device that can freely adjust the flow rate at the strip inlet side end of the plating tank. A uniform high flow rate is ensured throughout the entire plating bath, and the gist thereof consists of at least one pair of replaceable soluble electrodes spaced apart on both sides of the continuously running strip; The soluble electrodes and the strips are immersed and held in a plating tank below the surface of the electrolytic solution, and the strips are placed at the center of each soluble electrode in the strip running direction and at the end of the plating tank on the strip outlet side. A pair of nozzles for discharging the electrolyte in a countercurrent to the running direction of the strip are provided on both sides of the strip, and an electrolyte outflow device with a freely adjustable flow rate is provided on the strip inlet side of the coating tank. This is an open continuous electroplating device equipped with a soluble electrode.

In this way, the open type continuous electroplating device according to the present invention (
According to the multi-stage countercurrent method), not only the electrodes are uniformly melted in the width direction of the strip, but also a constant high flow rate of the electrolyte can be ensured regardless of the length of the plating tank. Furthermore, since there is no flow of electrolyte toward the strip exit end of the plating tank, foreign objects in the plating tank are prevented from getting caught in the rolls and causing indentation scratches. can be prevented.

In addition, in the multi-stage countercurrent method of the present invention, by providing an electrolyte outflow device that can freely adjust the flow rate at the strip inlet side end of the plating tank, preferably at the strip inlet, the electrolyte in the plating tank can be drained. The flow can be made uniform throughout the entire plating tank, and the generation of vortices on the wall surface of the plating tank, thereby preventing the occurrence of uneven plating or the intrusion of foreign matter, etc.

The invention will now be described in conjunction with the accompanying drawings.

The accompanying drawing is a schematic cross-sectional view of a device according to the invention, in which a strip 1 running continuously in the direction of the arrow is centered, with soluble electrodes 2 spaced apart on both sides thereof. In the illustrated example, two pairs of these soluble electrodes are provided in front and behind each other. Furthermore, pairs of electrolyte countercurrent discharge nozzles 4.4 are arranged at the center of the plating tank 3 and at the strip outlet side end of the plating bath 3 in the strip running direction. These electrolyte countercurrent discharge nozzles 4 may be slit-shaped nozzles extending in the direction of the strip, thereby discharging the electrolyte uniformly in the direction of the strip and countercurrently with respect to the running direction of the strip. Electrolyte countercurrent discharge nozzle 4
As described above, the shape and structure are not particularly limited as long as the countercurrent flow pattern can be made uniform.

A variable dam seal 5 is provided at the end of the plating tank 3 on the strip inlet side, which constitutes an electrolyte outflow device whose flow rate can be adjusted. On the other hand, a dam roll 6 is provided at the opposite end of the plating bath 3 to prevent leakage of the electrolyte. By adjusting the flow rate from the variable dam seal 5,
A uniform flow pattern of the electrolyte can always be obtained even near the inlet end of the strip.

As described above, the present invention adopts a multi-stage countercurrent system and provides countercurrent discharge nozzles not only at the end of the strip exit side of the plating tank but also in the center thereof, thereby uniformly discharging the entire plating tank. This allows a high flow rate to be ensured.

Furthermore, in the multi-stage countercurrent method of the present invention, the electrolyte flows out of the plating tank from the strip inlet end, so by adjusting the flow rate, a uniform flow pattern can be achieved throughout the plating tank. You can get it. For example, in the conventional method where a dam roll is also provided at the end of the strip inlet to prevent electrolyte leakage and allow overflow while maintaining a constant electrolyte level, the flow of electrolyte is directed toward the dam roll or the wall of the plating tank. They collide and generate vortices, which adversely affect plating quality.

In addition, in the figure, numerals 7.8 and 9 indicate an energizing roll, a support roll, and a plating tank, respectively. In this way, the electrolyte is constantly circulated between the plating tank and the plating bath.

Thus, according to the present invention, as is clear from the above explanation, uniform dissolution in the middle direction of the soluble anode can be achieved, and a uniform flow velocity distribution can be obtained in the strip running direction, making it possible to achieve high-quality plating efficiently. It can be implemented practically.

[Brief explanation of the drawing]

The accompanying drawing is a schematic cross-sectional view of an open continuous electroplating device according to the invention. 1. Strip 2. Soluble electrode 3. Plating bath 4. Countercurrent discharge nozzle 5. Variable dam seal Applicant Sumitomo Metal Industries Co., Ltd. Agent Patent attorney Akira Hirose −

Claims (1)

[Claims] at least one pair of replaceable soluble electrodes spaced apart on either side of the continuously running strip;
The soluble electrodes and the strips are immersed and held in a plating tank below the surface of the electrolytic solution, and the strips are placed at the center of each soluble electrode in the strip running direction and at the end of the plating tank on the strip outlet side. A pair of nozzles for discharging electrolyte in a countercurrent to the strip running direction are provided on both sides of the plating tank, and an electrolyte outflow device whose flow rate can be adjusted is provided on the strip inlet side of the plating tank. , an open continuous electroplating device with soluble electrodes.