JPH049876B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) Currently, there are the following electroplating methods. (1) Horizontal type, jet method from the side side (2) Horizontal type, jet method from the line direction (3) Horizontal type, jet method from the bottom and top surface (4) Vertical type, immersion, jet method from the bottom surface (5) Vertical type, immersion, jet type just before stripping (6) Vertical type, immersed type, jet type with alternating bottom and top surfaces, etc. However, with these methods, (1) When plating one side, the side that is not to be plated is also lightly plated. (2) Even if you do not want to plate the ends of the strip.
Approximately 10mm of plating will adhere. (3) Since it is not possible to ensure a uniform flow velocity distribution in the width direction of the plate, it is not possible to ensure uniform properties of the plating layer. (4) When plating both sides, a lot of the plating parts stick to both ends. There were many problems. Furthermore, JP-A-59-89792 discloses a method in which a plating solution is caused to flow non-horizontally between the strip and an anode by gravity when a metal layer is continuously electroplated on one or both sides of a strip metal. There is. However, in this method, the plating liquid flows simply by gravity, so if the water level difference between the upper and lower parts of the anode is a, a difference in flow velocity of √2 occurs. However, g
is the gravity, which is 9.8m/sec ² . For example, the flow velocity above the anode is approximately 0 m/sec, while at 1000 mm below it is 4.42 m/sec, resulting in a large difference in the flow velocity ratio. If the flow rate ratio is greatly different in this way, the Fe content distribution in the plating layer will be greatly different in alloy plating, such as zinc-iron alloy plating, and this will affect the corrosivity of the plating layer, secondary paint adhesion, and plating peeling. It becomes a big problem in terms of gender etc. Furthermore, in the vertical pass, the difference between the relative flow velocity with the strip in the up pass and the relative flow velocity in the down pass is twice the line speed, and quality is improved by zinc-iron alloy plating, zinc-Ni alloy plating, etc. This causes the above problem. Furthermore, since the plating liquid is dropped only by gravity, its speed is limited, and as the line speed increases, the problem arises that the liquid blows upstream in the uppath. For example, if the line speed is 120m/min, the line speed is 2m/sec.
sec, and V=√2 at the top of the anode, so 2
At a liquid level of less than m/sec, the plating liquid is lifted upward, and the space between the anode and the strip is not completely filled with the plating liquid, and as a result, the gas phase is drawn in, causing plating pinholes. (Technical Problem to be Solved by the Invention) The present invention is designed to flow the plating liquid almost uniformly in the longitudinal direction of the gap between the strip and the electrode using small equipment, and to prevent the entrainment of the gas phase. It is possible to improve the quality of strips, etc. and reduce power costs.Furthermore, plating on one side can be easily manufactured with good quality, it is possible to prevent plating overcoat on both ends of the strip, and it is possible to perform plating with less plating resistance voltage. Moreover, it is an object of the present invention 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 such that the strip is made to run along the electrodes arranged vertically or inclined at a predetermined angle with a certain gap from the electrodes, and at the same time is placed above the electrodes. This is an electroplating method in which the strip is plated by forcing plating liquid to flow down from a nozzle into the gap between the electrode and the strip at a desired flow rate, and the gap between the nozzle installation location and the gap is sealed with the plating liquid. . The 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 constant gap from the electrode. An electric plating device comprising: a nozzle that is arranged to force plating liquid 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 liquid. It is a device. Furthermore, a third aspect of the present invention is an adjustment mechanism for detecting the strip width or the amount of strip meandering in the second aspect, and adjusting the seal width of the seal mechanism and the jet width of the plating liquid jetted from the nozzle based on the detected value. This is an electroplating method with additional features. (Embodiment) FIG. 1 is a schematic diagram of an electroplating device showing an embodiment of the present invention, and FIG. 2 is an enlarged view of the main parts of the same device. In this device, a plurality of vertical plating tanks 10 are arranged in a row, and two pairs of anode electrodes 11, 11 and 12, 12 are arranged in each plating tank 10 in a vertical direction (or inclined at a predetermined angle). , the strip 13 is vertically introduced between the anode electrodes 11, 11 from above and led out downward, and then introduced into the anode electrodes 12, 12 from below through the roll 14 and led out upward, and then transferred to the next plating tank. 10. On the other hand, the plating liquid is ejected from the straight nozzle 16 through the nozzle header 15 into the gap between the electrodes 11, 11 and the strip 13. Metsuki liquid is
After passing through the gap, it enters the plating liquid tank 17. The plating liquid ejected from the nozzles 16 and 18 has an initial velocity of 1 m/sec or more, practically 2 m/sec to 8 m/sec.
Blows out as m/sec. The spray angle from the nozzles 16 and 18 is set to 0 in the running direction of the strip 13.
In terms of degrees, it is 0 to 70 degrees, preferably 0 to 45 degrees. A sealing mechanism shown in FIG. 2 is installed at the part of the plating liquid blowing section that comes into contact with the strip 13 to prevent the air entrainment phenomenon that tends to occur when the plating liquid is blown out. In this sealing mechanism, the sealing liquid (same composition as the plating liquid) is pumped into the pump 18.
The liquid is then sent to the sealing liquid supply box 19 via valve V ₁ or V ₂ . The sealing liquid in box 19 is
The liquid passes through the liquid level adjustment gate 20 and is stored in the sealing liquid storage section 21 . This storage section 21 is connected to the electrode 11 or 1.
2 and the strip 13 through a liquid seal throat portion 22. This throat portion 22 performs liquid sealing. The liquid seal throat portions 22 are preferably spaced as narrowly as possible. Based on the experimental results, the appropriate seal interval d ₁ of the throat portion 22 that can prevent air from entering is the jet velocity from the nozzle V ₀ m/sec and the liquid level maintenance pump discharge amount Qm ³ /sec, then d ₁ = f × ( The relationship is Q/V ₀ ) (f is an experimental coefficient), and in general (d ₁ is 3 mm to 8 mm), if d ₁ is too large, air will enter the plating liquid and good plating conditions cannot be maintained. . 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 to ensure good plating conditions, the initial velocity of the jet from the straight nozzle 16 is V ₀ m/sec. is as follows. Nozzle outlet spacing: d ₀ Flow rate Q ₀ Liquid seal throat spacing: d ₁ Flow rate Q ₁ Same Flow velocity: v ₁ Anode bottom (outlet) spacing: d ₂ Flow rate Q ₂ Same Flow velocity: v ₂ , then Q ₂ = Q From the relationship of ₀ + Q ₁ , v ₂ d ₂ = V ₀ d ₀ + v ₁ d ₁ , and the nozzle blowout flow velocity V ₀ is V ₀ = v ₂ d ₂ −v ₁ d ₁ /d ₀ . Furthermore, in the up-pass of the strip, the flow is counter-current to the direction in which the strip travels, and in the down-pass, the flow is parallel to the strip, so that the relative velocity differs for the same jet velocity.
Therefore, separate variable flow rate pumps are used for up-pass and down-pass. When the line speed is Lm/sec, the down-pass flow velocity v is preferably set to v=v'+2L (m/s) relative to the up-pass flow velocity v'. It is especially important to maintain this in the case of iron-zinc alloy plating, which requires uniform flow velocity. In addition, 23 in Fig. 1 is a downstream path jet pump, 2
4 is a liquid seal liquid level maintenance pump, and 25 is an energized roll. In FIG. 2, 26 is a jet guide portion, and 27 is a sealing liquid receiving port. 3 and 4 show a mechanism for adjusting the width of the sealing liquid and the jetting 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 consists of two members 20a and 20b whose upper surfaces are inclined. Both members 20a and 20b are movable in the horizontal direction, and the liquid seal width is changed by this movement. Nozzle ejection width adjustment spools 16a and 16b are disposed on both sides of the nozzle 16 so as to be movable in the horizontal direction, and the ejection width of the plating liquid is changed by this movement. The liquid seal width and the plating liquid jetting width are changed as follows. A strip width and meandering detection device 30 detects both ends of the strip and sends the signals to a work side cylinder 31 and a 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 slid from side to side in the board width direction using cylinders 31 and 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 of the liquid level and the sloped surface of the gate. Even when the strip meanderes, each member 20a and 20b of the liquid level adjustment gate slides and is set at a position that matches the strip position to maintain the seal width. Next, the nozzle jet width adjustment will be described.
Nozzle jet width adjustment spool 16 according to board width
a and 16b are slid left and right by the cylinders 31 and 32, and the plating liquid is ejected only over the required strip width. If the strip is meandering, use the adjustment spool 16.
a and 16b similarly slide according to the strip position. Next, specific examples will be described. Example 1 Double-sided plating (1) Test conditions (see Figure 5) Line speed 80 m/min Strip size 1.0 x 1000 mm Plating type Pure Zn Coating amount Double-sided plating 30 g/m ² /30 g/m ² Number of trays 9 trays Blow-out using double-sided anode Nozzle spacing d ₁ 11mm Initial blowing speed V ₀ 3m/sec Liquid seal height l ₁ 170mm Seal gap d ₂ 5mm Distance between electrodes d ₃ 10mm Anode electrode length l ₂ 1100mm Plating liquid main component ZnSO ₄ (PH=1.4) Liquid Seal width 1040mm Plating liquid spray width 1040mm (2) Results (a) Adhesion distribution in the board width direction If the conventional vertical method was used, as shown in Figure 6, the amount of adhesion at both ends would be significantly different compared to the center. . On the other hand, the coating amount distribution in the width direction of the plate plated by the method of the present invention is uniform with no large amount of plating attached to both ends.The reason is that the plating jet spray width is adjusted according to the strip width, so that Zn ions are This is to prevent concentrated electrodeposition. (b) Reduction in plating voltage Compared to the conventional vertical method, the distance between the poles is shorter and the plating flow speed is faster, so as shown in the table below, the plating voltage is reduced and power consumption can be saved.

[Table] Example 2 Single side plating (1) Test conditions Line speed 60m/min Strip size 0.8×1220 Plating type Pure Zn Amount of coating Single side plating 0/40g/m ² Number of trays 9 trays Only one side anode used Blowout nozzle spacing 11mm Blowout initial speed V ₀ 2m/sec Liquid seal height 160mm Seal gap 5mm Distance between electrodes 10mm Anode electrode length l ₂ 1100mm Plating liquid main component ZnSO ₄ (PH=1.4) Liquid seal width 1250mm Plating liquid injection spray width 1250mm (2) Results (a) ) Amount of adhesion on non-plated surface The average amount of adhesion on the three points at both ends and center of the non-plated surface is 500 mg/m ² in the conventional method, but is less than 10 mg/m ² in the present invention. The reason is that since the plating liquid is not sprayed on the non-plated surface, the plating does not come into contact with the plating liquid and no plating is attached. (b) Plating adheres to both ends of the non-plated surface In the conventional method, both ends of the non-plated surface
The adhesion amount distribution is as shown by the solid line in the figure.
According to the present invention, almost no adhesive is attached to both ends as shown by the broken line. Example 3 Iron-zinc alloy plating (1) Test conditions Line speed 50m/min Strip size 0.7×1300 Plating type Iron-zinc alloy plating deposit 0/40g/m ² Number of trays 9 trays Single-sided anode used Blowout nozzle spacing 11mm Initial blowing speed 6m/sec Liquid seal height 200mm Seal gap 5mm Electrode distance 10mm Anode electrode length l ₂ 1100mm Plating liquid main components ZnSO ₄ , FeSO ₄ Liquid seal width 1340mm Plating liquid spray width 1340mm (2) Results (a) Alloy plating layer Uniformity of Fe content in conventional methods (for example, Japanese Patent Laid-Open No. 59-89792), the flow path differs greatly between the upper and lower parts of the anode electrode. For example, the flow rate is 1.5m/sec at the top, 4.5m/sec at the bottom, and the flow velocity ratio is 300%. The Fe content of the Fe--Zn plating layer is greatly influenced by the flow rate of the plating liquid flowing between the anode electrode and the strip, as shown in FIG. 8, for example. Therefore, when the conventional method (Japanese Patent Application Laid-Open No. 59-89792) is used, 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 with 9 trays, it will look like Figure 10. On the other hand, when the method of the present invention is used and the initial velocity of the upper anode electrode is 6 m/sec, the upper anode speed is 6 m/sec.
sec, 9 m/sec at the bottom, and the flow rate ratio is within about 50% increase. Therefore, the Fe content distribution is as shown in FIG. 11, which is significantly different from that shown in FIG. 9, and can be manufactured with good quality. When this is plated with nine trays, the result shown in Fig. 12 is obtained, resulting in a uniform Fe 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 the present invention, since the plating liquid is ejected from the nozzle, the difference in flow velocity between the upper and lower parts can be reduced.Moreover, the plating liquid is ejected from the upper part by the nozzle, and the sealing mechanism is 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 liquid is sprayed only between the electrode and the strip, it is difficult for the plating liquid to enter the non-plated side when plating one side, and the jet width of the plating liquid is adjusted according to the strip width. Therefore, an increase in the amount of adhesion to the strip edge can be prevented. As a result, single-sided plating can be performed well. In addition, the distance between the electrodes can be shortened to reduce plating power consumption.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an electroplating device showing an embodiment of the present invention, FIG. 2 is an enlarged view of the main parts of the device, and FIG.
4 and 4 are explanatory diagrams showing the adjustment mechanism for sealing liquid width and plating liquid jetting width, FIG. 5 is a diagram showing an example of the specifications of the electroplating apparatus used in the example, and FIG. FIG. 7 is a diagram showing the results of Example 2. FIG. 8 is a diagram showing the relationship between the flow rate of the plating solution and the Fe content of the Fe-Zn plating layer, and FIGS. 9 and 10. 11 and 12 are diagrams showing the results of the conventional example used as a comparison target in Example 3, and FIGS. 11 and 12 are diagrams showing the results of Example 3. 10... Vertical plating tank, 11, 12... Electrode,
13...Strip, 14...Roll, 15...
Nozzle header, 16... Nozzle, 17... Mekki liquid tank, 18... Upstream pass jet pump, 19...
Seal liquid supply box, 20... Liquid level adjustment gate, 21... Storage section, 22... Liquid seal throat section, 23... Jet pump for downstream path, 24...
Liquid seal liquid level maintenance pump, 25... energizing roll, 26... jet flow guide section, 27... seal liquid receiving port, 30... detection device, 31... work cylinder, 32... drive side cylinder.

Claims (1)

[Scope of Claims] 1. A strip is made to run along an electrode arranged vertically or inclined at a predetermined angle and at a constant distance from the electrode, and at the same time, from a nozzle arranged above the electrode, the distance between the electrode and the strip is An electroplating method in which the strip is plated by forcing a plating liquid to flow down at a desired flow rate, and the gap between the nozzle installation location and the upper part of the above-mentioned gap is sealed with the plating liquid. 2. In an electroplating device in which a strip runs along an electrode arranged vertically or at a predetermined angle and at a constant distance from the electrode to perform strip plating, the strip is arranged above the electrode and the distance between the electrode and the strip is a nozzle that forces the plating liquid to flow down at a desired flow rate, and a sealing mechanism that seals the plating liquid between the nozzle installation location and the upper part of the above-mentioned interval, and this sealing mechanism has a sealing liquid reservoir and a sealing mechanism. An electroplating device comprising: a liquid seal throat portion communicating with the sealing liquid storage portion and an upper portion of the gap and causing the sealing liquid in the sealing liquid storage portion to flow down to the upper portion of the gap. 3. In an electroplating device in which a strip runs along an electrode arranged vertically or inclined at a predetermined angle and at a constant distance from the electrode to perform strip plating, the strip is arranged above the electrode and the distance between the electrode and the strip is a nozzle that forces the plating liquid to flow down at a desired flow rate; a sealing mechanism that seals the gap between the nozzle installation location and the above-mentioned interval with the plating liquid; and a strip width or strip meandering that is detected and based on this detected value. a mechanism for adjusting the seal width of the seal mechanism and the jet width of the plating liquid ejected from the nozzle; an electroplating device, the electroplating device comprising: a liquid seal throat portion communicating with the sealing liquid storage portion to cause the sealing liquid in the sealing liquid storage portion to flow down to the upper part of the gap;