JPS61190096A - Electroplating installation - Google Patents

Abstract

PURPOSE:To prevent the spreading of plating to a non-plating surface in the case of one-side plating by placing rectangular plate-shaped anode plates on both sides of a steel strip traveling in a vertical direction and providing electrically insulating edge masks to both ends of the steel strip therebetween. CONSTITUTION:The steel strip S is vertically moved upward and downward by conductor rolls 31, 32 in a plating cell 1 and is passed through the inside of two sets of a plating chamber 18 consisting of a pair of the rectangular plate-shaped anodes 5, 5. The plating liquid E supplied by a plating liquid E circulation pump 26 is supplied from nozzles 23 of supply pipes 22 into the chamber 18 and electricity is conducted to the strip S as the cathode, by which the strip is plated. The impression of the voltage to one anode out of a pair of the anodes 5 is stopped in the case of plating only on one side of the strip S. The electrically insulating edge masks 35 which can be moved forward and backward by driving bars 37 are disposed to both ends of the steel strip between a pair of the anodes 5 and 5 to cover the ends of the strip S by which the substantial flow of the plating current to the steel strip side ends facing the anodes 5 is obviated and the spreading of the plating to the non-plating surface is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electroplating installation, in particular an installation for continuous electroplating on one or both sides of a vertically running metal strip.

The invention is applied, for example, to equipment for electrodepositing zinc, soot, nickel, etc. on one or both sides of a copper strip.

(Prior Art) As a method of electroplating one or both sides of a strip, there is a method of continuously electroplating while running the strip in a vertical direction. In so-called vertical electroplating equipment that performs this type of electroplating, a pair of plate-shaped electrodes (anodes) are placed in a plating solution tank and face each other with their electrode surfaces perpendicular. A conductor roll is placed in each. A plating solution is supplied between the electrodes. Plating is carried out by passing a strip (cathode) guided by a conductor roll between the electrodes. The plating solution is supplied between the electrodes using a plating solution supply device or by immersing the electrodes in the plating solution.

As an example of such equipment, Japanese Patent Application No. 513-89792
There is an electroplating equipment disclosed in the publication.

(Problems to be Solved by the Invention) By the way, in conventional vertical electroplating equipment, there is a problem in that when plating one side, the plating runs around the side edge of the non-plated surface. That is, since the current density is generally higher on the side edge side of the strip than on other parts, a small amount of plating metal is electrodeposited on this side even if no voltage is applied to the electrode facing the non-plated side.

(Means for Solving the Problems) The electroplating equipment of the present invention includes a plating solution tank, a pair of opposing plate electrodes arranged in the plating solution tank with the plate surfaces vertical, and an upper part of the electrodes. and a conductor roll placed below.

and a plating solution supply device. Opposing electrodes form a plating chamber.

An electrically insulating edge mask covering the side edges of the strip between the electrodes is provided so as to be movable in and out in the width direction of the strip.

(Function) When performing single-sided plating, voltage is applied only to the electrode facing the surface to be plated. The edge mask is positioned so as to cover both ends of the strip.Since both ends are covered by the edge mask, sufficient plating is formed on the side facing the electrode to which no voltage is applied. No current flows, so there is no plating in this area.

(Example) FIG. 1 shows an example of the present invention, and is a longitudinal sectional view of a vertical electroplating equipment.

As shown in the drawing, the vertical electroplating equipment mainly consists of a plating solution tank 1, two sets of rectangular plate electrodes 5. It is composed of conductor rolls 31 and 32, a plating solution supply device i22, and an edge mask 35.

The plating solution tank 1 consists of a container that opens upward. The plating solution tank 1 collects the plating solution E flowing down from the upper plating chamber 18 at the bottom.

Each electrode 5 is an insoluble electrode in the shape of a rectangular plate, and consists of a pair of plate surfaces facing each other. The plate is supported in the plating solution tank 1 with its surface vertical and forming a plating chamber. The electrode 5 is connected to a feeding conductive band (not shown) and is maintained at a positive potential with respect to the strip S.

Directly above the electrode 5 is a pair of plating solution supply headers 22.
is located. Each plating solution supply header 22 is equipped with a nozzle 23 directed toward the plating chamber 18 .

Further, a liquid shut-off device 9 is attached to the lower end of the electrode 5 and includes a shut-off plate that can be moved in and out. The liquid shut-off device 9 divides the opening at the lower end of the plating chamber 18 by a closing plate to adjust the amount of the plating liquid E flowing out from the plating chamber 1B.A plating liquid circulation pipe is provided at the bottom of the plating liquid tank 1. 25 is connected, and the plating solution E is supplied to the plating solution supply header 22 by a plating solution circulation pump 26.

Conductor bars 31, 32 are arranged above and below the electrode 5, respectively. Conductor roll 31
．． 32 guides the strip S so as to keep a constant distance between it and the electrode 5.

Strip S in contact with conductor roll 31.32
is maintained at a negative potential with respect to ta5.

As shown in FIGS. 2 and 3, a pair of edge masks 35 made of an electrically insulating material are provided between the electrodes 5 so as to be movable in and out. The edge mask 35 has a U-shaped cross section so as to cover the side edge of the strip S.
It extends vertically to almost the full length of the electrode 5.

A drive rod 37 passing through the side wall 3 of the plating solution tank 1 is connected to the back of the edge mask 35. The drive rod 37 advances and retreats from the edge mask 35 by a drive device (not shown) such as a hydraulic cylinder connected thereto.

A rubber shielding sheet 3 is attached to the back of the edge mask 35.
One end of the shielding sheet 38 is fixed, and the other end of the shielding sheet 38 is fixed to the inner surface of the side wall 3 of the plating solution tank l. The shielding sheet 39 is slack when the edge mask 35 is retracted so that the shielding sheet 3S can expand and contract as the edge mask 35 moves forward and backward. The shielding sheet 39 electrically blocks the opposing electrodes 5 at the back of the edge mask 35 .

Next, the operation of the electroplating equipment configured as described above will be explained.

A plating solution is supplied from the plating solution supply nozzle 23 to the plating chamber 18 . The outflow amount of the plating solution is adjusted by the liquid shutoff device 9 so that the plating solution E fills the plating chamber 18 up to the upper end.

When performing single-sided plating, the electrode 5 facing the surface to be plated
Voltage is applied only to The position of the edge mask 35 is adjusted by the driving rod 37 so as to cover both ends of the strip S. Since both ends are covered by the edge mask 35, the side end facing the zero potential electrode 5 is The edge mask 35 does not allow sufficient current to form the plating, so the plating does not penetrate into this area.
The shielding width on the side end side varies depending on the current density, interpolar distance, and other plating conditions, but is approximately 10 to 100 m.

Further, the shielding sheet 39 electrically isolates the positive potential electrode 5 and the zero potential electrode 5 at the back of the edge mask 35 . Therefore, no unnecessary current flows between both electrodes 5.

Here, a specific example of electroplating using the above equipment will be described.

Electrolytic conditions in plating solution (1) ZnSOa 7H2O concentration: 250
Gel plating solution temperature = 60°C Plating solution pH: 1.5 Free H2SO4 in plating solution: 21 g/vertical anode-cathode distance: 9+am Liquid volume static pressure pad: 2 m3/sin One side auxiliary ladder: 0. 5 m3/in Unilateral static pressure (static pressure pad area): 425 am H20 edge mask:
Steel strip side end shielding width 5II11 (a) Dimensions of double-sided plated copper strip: Thickness 0.8 mm x width 1500 am Target coating amount: 20 g/m2 (rl) on both sides Dimensions of single-sided plated steel strip: Thickness 0. 75 thickness x width 1500 layers Target amount of plating coating on two surfaces 20 g/ls2 Back surface Q g/ra2 As is clear from the table above, in this invention, the plating does not spread to the end of the non-plated surface.

The present invention is not limited to the above-described embodiment; for example, a set of electrodes may be disposed within the plating solution tank, and the edge mask may be moved in and out by an electric device.

(Effects of the Invention) As described above, according to the present invention, when performing single-sided plating, the plating does not go around to the side edge side of the non-plated surface. Therefore, the non-plated surface is completely unplated. Single-sided plating is obtained.

[Brief explanation of drawings]

FIG. 1 shows an example of the present invention, and is a longitudinal sectional view of a vertical electroplating equipment, and FIG. 2 is a side view of the main parts of the equipment.
and FIG. 3 is a sectional view taken along the line ■-■ in FIG. 2. ■... Plating solution tank, 5... Electrode, 18... Plating chamber. 22... Plating solution supply header, 23... Nozzle,
26... Plating solution circulation pump, 11.32... Conductor roll, 35... Edge mask, 37...
Drive rod, 38... Shielding sheet, S... Strip,
E...Plating solution.

Claims (1)

[Claims] A plating solution tank, a pair of plate electrodes arranged in the plating solution tank so that their plate surfaces face each other vertically to form a plating chamber, a conductor roll arranged above and below the electrodes, and a plating chamber. 1. An electroplating equipment comprising a liquid supply device, characterized in that an electrically insulating edge mask covering the side end side of the metal strip between the electrodes is provided so as to be movable in and out in the width direction of the metal strip.