JPS62240793A - Method and apparatus for electroplating - Google Patents

Abstract

PURPOSE:To shorten the distance between both electrodes to enhance efficiency of electric power and to satisfactorily perform one-side plating by injecting plating liquid between vertically provided electrodes and a running strip and also providing a sealing mechanism, thereby preventing involution of gaseous phase. CONSTITUTION:A strip 13 is run along electrodes 11, 12 vertically or slantingly arranged. Plating liquid is simultaneously allowed to flow down through a nozzle 16 arranged to the upper part of the electrodes 11. 12 for the interval of the electrodes 11, 12 and the strip 13. The space of both the set part of the nozzle 16 and the upper part of the above-mentioned interval is sealed by a sealing mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) Currently, there are the following electroplating methods.

1) Horizontal type, jet flow from the side side 2) Horizontal type, jet flow from the line direction 3) Horizontal type,
4) Vertical, immersed, jet from the bottom 5) Vertical, 8P immersion, jet just before stripping 6) Vertical, immersed, alternating jet from the bottom and top, etc. However, with these methods: 1) When plating one side, the unplated side is also plated thinly.

2) 101 even on the sides where you do not want to plate the ends of the strip.
Some plating will adhere.

3> Because it is not possible to ensure a uniform flow velocity distribution in the width direction, it is not possible to ensure uniform properties of the plating layer.

4) When plating both sides, a lot of plated parts adhere to both ends.

There were many problems.

Also, JP-A-59-89792 Gk, gold mI! A method is disclosed in which, when continuously electroplating W on one or both sides of a strip metal, the plating solution is caused to flow non-horizontally between the strip and the anode by gravity.

However, in this method, the plating solution simply flows by gravity, so if the water level difference between the upper and lower parts of the anode is a, f
77] - flow velocity difference occurs. However, 0 is gravity, 9.8
10/'SeC2.

For example, the flow velocity above the anode is approximately Oi/sec, while at 1000 mm below it is 4.42 m/sec, resulting in a large difference in the flow velocity ratio.

When the flow rate ratio is greatly different in this way, in alloy plating, for example, zinc-iron alloy plating, the l”e in the plating layer
The content distribution varies greatly, which causes major problems in the corrosion of the plating layer, secondary coating adhesion, plating removability, etc.

Furthermore, in the vertical pass, the difference between the relative flow velocity with the strip in the up bath and the relative flow velocity in the down bath is twice the line speed, and the difference is twice the line speed. This results in quality problems.

Furthermore, since the plating solution is dropped only by gravity, its speed is limited, and as the line speed increases, the problem arises that the solution blows upstream in the up-pass. For example, if the line speed is 1
At 20 a+/l1in, the velocity is 2II/SeC per second, and V-r is positive at the top of the anode.In the liquid level below 2 m/sec, the plating solution is lifted upwards, and the space between the anode and the strip is completely filled with the plating solution. As a result, the gas phase is drawn in, creating pinholes in the plating.

(Technical Problem to be Solved by the Invention) The present invention allows the plating solution to flow almost uniformly in the longitudinal direction of the gap between the strip and the electrode using small equipment, and prevents the entrainment of gas phase. It is possible to improve the quality of the strips and reduce the power cost, and it is also possible to easily produce high-quality plating on one side at a time, to prevent over-coating of the plating at both ends of the strip, and to reduce the plating resistance voltage. The object of the present invention is to provide an electroplating method and apparatus that can be applied not only to low and medium speed lines but also to high speed lines.

(Means for Solving Technical Problems) The first invention is to run a strip along an electrode arranged vertically or inclined at a predetermined angle with a constant gap from the electrode, and at the same time from a nozzle placed above the electrode. ,
This is an electroplating method in which the strip is plated by flowing a plating solution at a desired flow rate into the gap between the electrode and the strip, and the gap between the nozzle installation location and the gap is sealed with the plating solution.

A second invention is an electroplating apparatus in which a strip is plated by running along an electrode arranged vertically or inclined at a predetermined angle and with a certain gap from the electrode, and the strip is arranged above the electrode. This electroplating apparatus is equipped with a nozzle that allows a plating solution to flow down at a desired flow rate into the gap between an electrode and a strip, and a sealing mechanism that seals the gap between the nozzle installation location and the upper part of the gap with the plating solution.

Furthermore, a third invention is a v4 adjustment in which the strip width or strip meandering l is detected in the second invention, and the seal width of the seal mechanism and the jet width of the plating liquid jetted from the nozzle are adjusted based on the detected value. This is an electroplating method with an additional mechanism.

(Embodiment) FIG. 1 is a schematic diagram of an electroplating apparatus showing an embodiment of the present invention, and FIG. 2 is an enlarged view of the main parts of the same apparatus. This device has a plurality of vertical plating tanks 10 arranged in a row, and two pairs of anode electrodes 4111.11 and 12.12 arranged vertically (or inclined at a predetermined angle) in each plating tank 10. , the strip 13 is vertically introduced between the anode electrodes 11.11 from above and led out downwardly, passed through the roll 14 into the anode electrode ff112.12 from below and led out upwards, and then the next plating l110 It leads to On the other hand, the plating liquid is ejected from the straight nozzle 16 through the nozzle header 15 into the gap between the electrode 11.11 and the strip 13. The plating solution enters the plating solution tank 17 after passing through the gap. The plating liquid ejected from the nozzles 16 and 18 is ejected at an initial ejection speed of 1ill/SeC or more, practically 21/SeC to 811/SeC.

The spray from nozzle 16.18 is at an angle of strip 13.
If the running direction of is 0 degrees, then O to 70 degrees, preferably O
~45'''. A sealing mechanism shown in FIG. 2 is installed at the part where the plating solution comes into contact with the strip 13 to prevent the air entrainment phenomenon that tends to occur when the plating solution is blown out. In this sealing mechanism, the sealing liquid (same composition as the plating liquid) is sent from the pump 18 through the valve V! or v2 to the sealing liquid supply box 19.The sealing liquid in the box 19 passes through the liquid level adjustment gate 20 to seal the liquid. The liquid is stored in a liquid storage section 21. This storage section 21 communicates with the gap between the electrode 11 or 12 and the strip 13 via a liquid seal throat section 22. The throat section 22 performs liquid sealing.

The liquid seal throat portions 22 are preferably spaced as narrowly as possible. From the experimental results, the appropriate seal interval d of the throat portion 22 that can prevent air from entering is determined by the jet flow velocity from the nozzle Va m/sec, the liquid level maintenance pump discharge amount Q I3/
Sec, the relationship is dl-(X (Q/Vo) (+ is the experimental coefficient), and generally (dl is 31i to 8I
IIn, and if )dl is too large, air will enter the plating solution, making it impossible to maintain good plating conditions.

In order to maintain as uniform a flow velocity as possible and an appropriate predetermined flow velocity between the slip 1 and the anode electrode 11 or 12 and to ensure good plating conditions, the initial velocity vom, "sec" of the jet from the straight nozzle 16 must be It is as follows.

Nozzle outlet interval = do flow jlQ.

Liquid seal throat spacing 2 dri Flow IQt same
Flow velocity = v! Anode bottom (outlet) spacing: d2 Flow rate Q2 Same
If the flow velocity is v2, then from the relationship 02-QO+Qt, V2d2=Vo do +Vt Ll, and the nozzle blowout flow velocity Va is furthermore, in the up-pass of the strip, the flow is countercurrent to the strip advancing direction, and in the down-pass, the flow is parallel, and at the same jet velocity, the flow is relative. The speed will be different.

Therefore, separate variable flow rate pumps are used for the 7-up pass and the down pass. When the line speed is L m /sec, the down-pass flow velocity V is preferably v=v'+2L (y71/s) with respect to the up-pass flow velocity V'.

It is especially important to maintain this in the case of iron-zinc alloy plating, which requires uniformity of flow velocity.

In FIG. 1, 23 is a downstream path jet pump, 24 is a liquid seal liquid level maintenance pump, and 25 is an energized roll. Second
In the figure, 26 is a jet guide portion, and 27 is a sealing liquid receiving port.

FIGS. 3 and 4 show a mechanism for adjusting the width of the sealing liquid and the spouting width of the plating liquid when the width of the strip 13 changes or when the strip 13 meanders. The liquid level adjustment gate 20 has two members 20a and 20 whose upper surfaces are inclined.
Both members 20a and 20b are movable in the horizontal direction, and the width of the liquid seal is changed by this movement. Nozzle ejection width adjustment spools 16a and 16b are arranged on both sides of the nozzle 16 so as to be movable in the horizontal direction, and the ejection width of the plating solution is changed by this movement.

The liquid seal width and the plating liquid jet width are changed as follows.

The strip width and meandering detection device 30 detects both ends of the strip and sends the signals to the work side cylinder 31 and the drive side cylinder 32.

In order to adjust the liquid seal width using the signal, each member 20a, 20b of the liquid level adjustment gate 20 is connected to the cylinder 3.
1. Slide left and right in the board width direction at step 32. When the plate width becomes wider, the member 20a moves to the work side member 20b to the drive side.

Since the liquid level remains the same, the liquid seal width expands to the width of the intersection between the liquid level and the sloped surface of the gate.

Each member 20 of the liquid level adjustment gate even when the strip is meandering.
a and 20b slide and are set at the slip 1 to slip positions to maintain the seal width.

Next, the nozzle jet width adjustment will be described.

Nozzle jetting width V4 adjustment spool 16a according to board width.

16b slides left and right by the above-mentioned sills 31 and 32, and the plating liquid is ejected only over the required strip width.

Adjustment spool 16a when the strip is meandering.

16b similarly slides according to the slip position.

Next, specific examples will be described.

(Example 1) Double-sided plating 1) Test conditions (see Figure 5) Line speed 80m/min Strip size 1.0X100Os Plating type Pure Zn Coating amount Double-sided plating 30g/TIt/30g/Td Number of trays 9 trays Blowout using double-sided anode Nozzle spacing 61 11 #1 Initial blowing velocity Vg3m/sec Liquid seal height Jll 170m Seal gap d25111 Interelectrode distance d310III 7-node electrode length J121100m Main component of plating solution Zll 804 (pH"" 1.
4) Liquid seal width: 10401M Plating liquid spray width: 1040# 2) Results a) Adhesion distribution in the board width direction If the conventional vertical method was used, the adhesion layer at both ends would be larger than the center, as shown in Figure 6. It's very different.

On the other hand, the coating amount distribution in the width direction of the plate plated using the method of the present invention is uniform without a large amount of plating adhering to both ends. This is because 111 is not performed in a concentrated manner.

b) Reduction in plating voltage Compared to the conventional vertical type method, the distance between the electrodes is shorter and the plating flow rate is faster, so as shown in the table below, the plating voltage can be reduced and the power consumption for plating can be saved.

(Example 2) Single side plating 1) Test conditions Line speed 60 m/lin Strip size 0.8x1220 Plating type Pure ZN included! fft Single side plating O/40 (1/Number of trays 9 trays Only one side anode used Blowout nozzle spacing
11mm Initial blowing speed 2m/SeC Liquid seal height 160m Seal gap 5m Interelectrode distance 10m Anode electrode length J12 1100#+llI plating liquid main component Zn SO4 (pH-1, 4) Liquid seal width
1250 layer plating solution spray width 1250m + 2) Results a) Amount of adhesion on non-plated surface The average amount of 3 points at both ends and center of the non-plated surface is 500q/Td in the conventional method, but in the present invention it is 10uIg.
/A or below.

The reason is that since the plating solution is not sprayed on the non-plated surface, the plating does not come into contact with the plating solution and no plating is attached.

b) Plating deposited on both ends of non-plated surface If the conventional method is used, the coating amount distribution at both ends of the non-plated surface is as shown by the solid line in FIG. Not attached at both ends.

(Example 3) Iron-zinc alloy plating 1) Test conditions Line speed 50 m/min Strip size 0.7x1300 Plating type Iron-zinc alloy plating W! t O/40M bottom]・Number of lays: 9 trays Single-sided anode used Blowout nozzle spacing: 11M Blowout initial velocity: 6 m/sea Liquid seal height: 200 m+ Seal gap: Distance between 5 layers: 10 feet Anode electrode length - t21100# Plating liquid main component: Zn 804, Fe 304 Liquid seal width 1340sx Plating liquid spray width 1340#1l12) Results a) Uniformity of Fe content in alloy plating layer In the conventional method (for example, JP-A-59-89792), the upper part of the 7-node electrode The flow velocity differs greatly between the upper and lower parts.

For example, 1.5 m/sec at the top, 4.5 m/sec at the bottom.

The flow rate ratio is 300%. F of Fe-Zn plating layer
The e content is greatly influenced by the flow rate of the plating solution flowing between the anode electrode and the strip, as shown in FIG. 8, for example.

Therefore, in the conventional method (Japanese Patent Laid-Open No. 59-89792), in the case of a vertical tray, the Fe content of the plating layer differs greatly between the upper and lower portions of the tray as shown in FIG.

If this is plated on nine trays, the result will be as shown in Figure 10.

On the other hand, when the method of the present invention is used, the initial velocity of the upper anode electrode is 6T.
When carried out with rL/SeC, the flow rate ratio is 5 Ill/SeC in the upper part and 97 FL/SeC in the lower part, and the flow rate ratio is limited to an increase of about 50%.

Therefore, the distribution of the content of l''e is as shown in FIG. 11, which is significantly different from that shown in FIG. 9 and allows production of good quality.

When this is plated on nine trays, the result shown in FIG. 12 is obtained, resulting in a uniform l''e content distribution, and it is possible to manufacture a rust-proof steel plate for automobiles with good paint adhesion (especially secondary adhesion) and secondary corrosion resistance.

(Effects of the Invention) According to this invention, since the plating liquid is ejected from the nozzle, the difference in flow velocity between the upper and lower parts can be reduced. By providing this, entrainment of the gas phase can be prevented, and therefore a high quality alloy plating layer with a desired composition can be reliably formed. In addition, since the plating solution is sprayed only between the electrode and the slip,
When plating one side, it becomes difficult for the plating solution to enter the non-plated surface, and since the plating solution jet width is adjusted according to the strip width, an increase in adhesion m to the strip edge can be prevented. As a result, single-sided plating can be performed satisfactorily. In addition, the distance between electrodes can be shortened to reduce plating power consumption.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing an electroplating apparatus showing an embodiment of the present invention, Fig. 5 is a diagram showing an example of specifications of the electroplating equipment used in the embodiment, and Fig. 6 is a diagram showing the results of Example 1. , FIG. 7 is a diagram showing the results of Example 2, and FIG. 8 is a diagram showing the flow rate of the plating solution and F
Figures 9 and 10 are diagrams showing the relationship with the 1''e content of the e-Zn plating layer, Figures 11 and 12 are diagrams showing the results of the conventional example that was the subject of comparison in Example 3. The figure shows the results of Example 3. 10...Vertical plating tank, 11.12... Electrode, 13
... strip, 14 ... roll, 15 ... nozzle header, 16 ... nozzle, 17 ... plating liquid tank,
18...Jet pump for upstream bath, 19...Seal liquid supply box, 20...Liquid level adjustment gate, 21...
Storage section, 22... Liquid seal throat section, 23...
Downstream path squirt pump, 24...Liquid seal liquid level maintenance pump, 25...Electrifying roll, 26...Jet flow guide section, 27...Seal liquid receiving port, 30...Detection device,
31...Work cylinder, 32...Drive side cylinder. Applicant's agent: Patent attorney Takehiko Suzue (Figure 1). Figure 6 5101520 3) 4oso
50 40 30 2015[5)-74rI V

Dry 7xide 9jL (m/5ec) Fig. 10 Fig. 11 Fig. 12

Claims (3)

[Claims] (1) A strip is made to run along an electrode arranged vertically or at a predetermined angle with a certain gap between the electrode and at the same time, a plating solution is applied from a nozzle placed above the electrode into the gap between the electrode and the strip. An electroplating method in which a strip is plated by flowing down at a desired flow rate, and a plating solution is used to seal between the nozzle installation location and the upper part of the gap. (2) In an electroplating apparatus in which a strip is plated by running along an electrode arranged vertically or inclined at a predetermined angle and with a certain gap from the electrode,
Electroplating comprising a nozzle that is placed above the electrode and causes the plating solution to flow down at a desired flow rate into the gap between the electrode and the strip, and a sealing mechanism that seals the gap between the nozzle installation location and the upper part of the gap with the plating solution. Device. (3) An electroplating device in which the strip is plated by running the strip along an electrode arranged vertically or inclined at a predetermined angle with a certain gap from the electrode,
A nozzle that is placed above the electrode and causes the plating solution to flow down at a desired flow rate into the gap between the electrode and the strip, a sealing mechanism that seals the space between the nozzle installation location and the gap with the plating solution, and the strip width or strip meandering amount. An electroplating apparatus comprising: a mechanism for detecting the detected value and adjusting the seal width of the seal mechanism and the jet width of the plating liquid ejected from the nozzle based on the detected value.