EP0975825A2

EP0975825A2 - Device for carrying out continuous electrolytic precipitation processes

Info

Publication number: EP0975825A2
Application number: EP98922686A
Authority: EP
Inventors: Hans Josef May; Roland Schnettler; Michel Collard
Original assignee: May Hans Josef; Schnettler Roland; Circuit Foil SA
Current assignee: Andritz AG; Circuit Foil Luxemburg SARL
Priority date: 1997-04-18
Filing date: 1998-04-11
Publication date: 2000-02-02
Anticipated expiration: 2018-04-11
Also published as: MD2173F2; EP0975825B1; US6306268B1; DE59800799D1; PL336496A1; WO1998048083A3; CA2286813A1; BR9808683A; DE19716369A1; ATE201724T1; CN1251624A; WO1998048083A2; CA2286813C; JP2000510532A; RU2180021C2; MD990273A; ES2157661T3; MD2173G2; KR20010006412A; JP3237762B2

Abstract

A device (1) for carrying out continuous electrolytic precipitation processes has a cathodic live cylinder (3) whose top surface is electroconductive over its whole useful width. An anode A is arranged concentrically to and spaced apart from the cathodic live cylinder (3). An electrolyte flows through the space (6) separating the live cylinder (3) from the anode A. Shielding strips (9, 9') associated to the live cylinder (3) are located between the cathodic surface of the live cylinder (3) and the anode A and electrically shield the marginal regions of the live cylinder (3), thus protecting them from electrolytic coating. The useful region N of the live cylinder (3) for carrying out the electrolytic precipitation processes is located between the shielding strips (9, 9'). The side of the shielding strips (9, 9') facing the useful region N has a shoulder (25') which reduces to zero the thickness of a metal strip to be produced or coated on one side, in the marginal region of the metal strip up to the shielding strip edge, so that no coating is deposited on the live cylinder outside the useful region N. The device (1) is useful both for electrolytically producing metal strips and for electrolytically coating one side of metal strips.

Description

Device for performing continuous electrolytic deposition processes

The invention relates to a device for carrying out continuous electrolytic deposition processes comprising a rotating cathodic current roller with an electrically conductive surface over its entire usable width and one or more anodes arranged approximately concentrically to the current roller, with the spacing space located between the current roller and the anode is flowed through by an electrolyte containing the metal to be deposited in dissolved form, to which current roller in a peripheral arrangement are assigned means for preventing a coating of the areas not used in electrolytic deposition processes from the current roller.

A device for the production of electrolytic metal strips is known, for example, from US Pat. No. 2,044,415. A driven cathodic current roller forms a spacing space with anodes which are arranged concentrically to the cylindrical surface of the current roller and which are arranged around the current roller at an angle of approximately 160 degrees. The electrolyte containing the metal to be deposited flows through the space. When there is a current flow, the metal initially contained in dissolved form in the electrolyte is deposited on the cathodic surface of the current roller. Due to the rotating movement of the current roller, the electrolytic coating can then be removed as a film or thin metal strip after it emerges from the electrolyte and can be fed continuously to subsequent processing steps. In this known current roller, the entire current roller width is used for the electrolytic deposition processes to form the metal foil. So that the current roller in its edge area in the transition to its end faces is not subjected to an electrolytic coating, which would damage it, a rubber band with a circular cross section is used, which is located on the front edge of the current roller and on a non-conductive, on the Current roller supports the flange arranged on the end face. This sealing rubber band ensures that a current flow to the front of the Current role out and thus preventing electrolytic coating of these areas is avoided.

Due to the gap-related marginal prevention of electrolytic deposits, this known device is only suitable for producing metal strips or foils in a single width, namely the width of the current roller. However, this device is unsuitable for the production of metal strips of different widths. This known device is also not intended for one-sided electrolytic coating of metal strips.

A device for one-sided electrolytic coating of metal strips is known from WO 94/10360. A metal strip to be coated on the outside is guided in contacting manner around the driven cathodic current roller. The metal strip is fed via a deflection roller with the smallest possible distance to the current roller and is continued on the opposite side via a further deflection roller after the coating. The metal strip passes through a space through which an electrolyte flows and in which the metal strip is electrolytically coated. Laterally, the space formed by the strip surface and the anode arranged opposite is delimited by seals which can be set up to adapt to different widths of metal strips to be coated in the axial direction of the current roller. These seals are supported with a sealing section in each case in the edge region of the metal strip to be coated. These supporting sealing sections contact the surface of the metal strip to be coated at a wrap angle that is so large that there is sufficient tightness when the metal strip enters the electrolyte.

With such a device, metal strips of different widths can be coated on one side. The sections of the current roller that are not used in the case of narrow metal strip widths are protected from electrolytic coatings, since these sections are not wetted with electrolyte due to the sealing measure. Even if this known device prevents an undesired electrolytic coating of the unused edge areas of the current roller, Especially when coating very thin metal strips, such as foils, supporting the sealing sections on the metal strips is disadvantageous. Especially in the case of very thin metal strips to be coated, these sealing sections, past which the metal strip to be coated is drawn, leave markings. The edge sections of such tapes or foils must then be cut off in a subsequent work step.

Electrolytic metal strip production cannot be carried out with an object according to WO 94/10360.

Based on this discussed prior art, the invention is therefore based on the object of proposing a generic device in which not only the usable area of the current roller can be set up and the unused areas of the current roller are effectively protected against undesirable electrolytic coatings, but with which both Electrolytic metal strip production and a one-sided electrolytic coating of metal strips is possible.

This object is achieved in that the current roller on each side is assigned a shielding tape protruding from the end face over the cylindrical surface of the current roller made of an electrically insulating material which is between the cathodic current roller and the anode or anodes and adjacent to the current roller area used for electrolytic deposition processes (useful area), electrically shielding the edge area of the current roller that is not used in the deposition process and surrounding the current roller at least at the fill level of the electrolyte, the side of a shielding tape facing the useful area pointing in this direction, has paragraph extending over the length of the shielding tape.

By providing a shielding band, expediently a flexible band of electrically non-conductive material, which is arranged surrounding the current roller in the region of the electrolyte, an electrically effective shielding between the anode or the anodes, which are expediently insoluble, and that covered by the shielding band Sections of the current roller serving as cathode created. An electrical current flow between the anode and the cathode therefore only takes place in the useful area of the current roller and thus in the areas not covered by the shielding tapes, so that an electrolytic coating is limited to the respective useful area of the current roller. In contrast, in the sections covered by the shielding tapes there is no current flow and therefore also no electrolytic coating. In order to ensure that an increased electrolytic coating of the current roller surface is also prevented in the edge region of a shielding tape facing the useful area, this has a shoulder directed towards the current roller. This also ensures that there is an edge-thinning layer thickness in the outer edge sections of the metal strip to be produced or coated, which is reduced to zero up to the strip edge, so that the current roller is not coated outside the useful area.

The useful area of the current roller can be determined, for example, by providing shielding tapes of different widths at the edges to shield the current roller for different deposition processes.

The device according to the invention is suitable both for the electrolytic production of metal strips or foils and for the one-sided electrolytic coating of metal strips, since the device for protecting the unused current roller sections is based on the principle of electrical shielding and not the principle of liquid sealing, as is the case, for example, with the subject matter of WO 94 / 10360 used, used. In the case of a one-sided electrolytic coating of metal strips, the edge region of the metal strip to be coated engages in the shoulder of the shielding strips facing the useful area, so that the lateral edge of the metal strip is already electrically shielded to such an extent that an excessive coating of these metal strip sections and a coating of the current roller in that section is protected from an electrolytic coating which borders directly on the area covered by the metal strip to be coated.

The two flexible shields used for shielding are expediently seed shielding tapes each projecting beyond the end face of the cathodic current roller. The sections protruding from the end faces can be used to adjust the two shielding tapes so that they are adapted to the width of the useful area of the current roller and thus to the width of the edge portion of the current roller to be shielded. With these shielding tapes, the useful width of the current roller can thus be set up by moving the shielding tapes to the respectively desired width of the useful area, without having to change the shielding tapes.

On its side facing the current roller, a shielding band supported on the surface of the current roller expediently has support webs and drainage grooves arranged alternately with the support webs. In addition to an electrolyte outlet which extends directly into the spacing space, the drain grooves also discharge electrolyte from the spacing space in this way. In addition, particularly in the case of thin metal strips to be coated, such as foils, the resulting suction causes the foil to be pressed against the current roller, particularly in its edge region, which promotes proper fixing of the foil to the current roller.

Retaining means are preferably assigned to each shielding band on its side pointing away from the useful area of the current roller and projecting beyond the end face of the current roller, said adjustment means being in engagement with an adjusting device for setting up the bands with respect to the width of the current roller edge to be shielded. In one embodiment, webs spaced apart from one another are provided as retaining means and are arranged in a row and are held in an approximately complementary receiving groove of a receiving piece. The spacing of the webs is chosen to facilitate threading a shielding tape into such a receptacle. Such a receptacle expediently engages piston-cylinder arrangements with which the setting up of a shielding band takes place with respect to the width of the current roller sections to be shielded. However, other means for setting up the receiving piece, such as spindles, possibly driven by a motor, are also conceivable. Further advantages and developments of the invention form part of the subclaims and the following description of a preferred exemplary embodiment. Show it:

1 shows a cross section through a device for one-sided electrolytic coating of metal strips along the line A-B of FIG. 2,

2 shows a longitudinal section through the device of FIG. 1 along the line C-D of FIG. 1,

3 shows an enlarged detail of the area marked “X” in FIGS. 2 and

Fig. 4 shows a section corresponding to the representation of Figure 1

Device for the production of electrolytic metal strips.

Figure 1 shows a device for one-sided electrolytic coating of metal strips (coating device) 1. The coating device comprises a trough 2, in which a cathodic current roller 3 is rotatably mounted. The direction of rotation of the current roller 3 is indicated by the arrow 4. The current roller 3 is an undivided current roller, the cylindrical surface of which is electrically conductive over the entire width of the current roller 3. Providing such an undivided current roller 3 avoids markings that occur, in particular, when thin metal strips are coated, such as occur with divided current rollers. The necessary anodes cannot be seen in the section shown in FIG. 1; these are located behind a retaining wall 5. The anodes used are insoluble anodes. The spacing space 6 formed by the surface of the current roller 3 and the anodes is traversed by an electrolyte which is continuously introduced into the spacing space 6 via an electrolyte feed 7 and drawn off via the device 7 '. The direction of supply of the electrolyte is indicated by arrow 8. The direction of flow of the electrolyte is thus in the same direction with respect to the direction of rotation 4 of the current roller 3. In a further embodiment, not shown, it is provided that the direction of flow of the electrolyte is opposite opposite to the direction of rotation 4 of the current roller 3 is provided. The marginal space 6 is delimited by a shielding band 9, 9 ', of which only the shielding band 9 can be seen in FIG. The side of the shielding tape 9 facing the current roller 3 is structured in a structured manner by alternately arranged support webs 10 and drain grooves 11. With the support webs 10, the shielding tape 9 is supported on the surface of the current roller 3 to be shielded. The drain grooves 11 serve to drain the electrolyte located in the spacing space 6 and each open into a collector 12 on the outside. In the deepest part of a collector 12 there is in each case an outlet 13 from which, according to the arrow 14, the electrolyte which has emerged from the drain grooves 11 is drawn off.

A metal strip 15 to be coated is deflected at a first deflection roller 16 to feed it into the spacing space 6. It is provided that the metal strip 15 already contacts the top of the cathodic current roller 3 before it enters the space 6 filled with the electrolyte. When passing through the spacing space, the desired coating then takes place on the outside of the metal strip 15. The metal strip 15 ′ coated after passing through the coating device 1 is carried on via a second deflection roller 17.

From the longitudinal section of the coating device 1 shown in FIG. 2, the arrangement of the two shielding tapes 9, 9 ′ in relation to the useful area N of the current roller 3 becomes clear. The upper part of the longitudinal section of FIG. 2 shows the shielding tapes 9, 9 ', which cut in the area of a support web 10, 10', while the shielding tapes 9, 9 'in the lower part of this longitudinal section each cut in the area of a drain groove 11, 11' are shown. The shielding tapes 9, 9 'have a width at which it is ensured that, even in the case of the metal tape with the smallest width to be coated, they protrude from the end over the current roller 3. With these end sections projecting beyond the end face of the current roller 3, the shielding tapes 9, 9 'each engage an adjusting device 18, 18' by means of which the shielding tapes 9, 9 'can be set with respect to the width of the edge section to be shielded by the current roller 3 are. For this purpose, the shielding tapes 9, 9 'on the outside in each case retaining webs 19, 19' which engage in a correspondingly shaped receptacle 20, 20 'of a receptacle piece 21, 21'. The retaining webs 19, 19 'are a plurality of individual webs spaced apart from one another.

In the area of the section of the shielding tapes 9, 9 'projecting beyond the end face of the current roller 3, outlet openings 22, 22' are introduced into the outlet grooves 11, 11 ', so that electrolyte escaping through these outlet openings 22, 22' into the collectors 12, 12 arranged below 'can expire.

The adjusting devices 18, 18 'each comprise two piston-cylinder arrangements, which are supported on the trough 2, by means of which the receiving pieces 21, 21' can be moved and set up axially with respect to the current roller 3. Figure 2 shows an arrangement of the shielding tapes 9, 9 ', which has been chosen only to illustrate the variability of the setup of the shielding tapes 9, 9'. It shows the shielding tape 9 with its adjusting device 18 in a position that would be selected to create a relatively wide useful area N, here: to coat a relatively wide metal tape. In contrast, the shielding tape 9 'with its adjusting device 18' is shown in a position which would be selected to form a relatively narrow usable area N, here: for coating a much narrower metal tape. In both cases it is ensured that the areas of the current roller 3 which are not used by the metal strip are electrically shielded by the shielding strips 9, 9 'and are therefore not subject to any electrolytic coating. In the normal case, however, the shielding tapes 9, 9 'are arranged centered with respect to the center line 23 of the current roller 3.

The shielding tapes 9, 9 'can be set up by means of their adjusting device 18, 18' via a correspondingly positioned photocell with which the respective width of a metal strip 15 to be coated on the current roller 3 is detected. The adjusting devices 18, 18 'for setting up the shielding tapes 9, 9' are then controlled via a control device acted upon by such a photocell.

The arrangement of the shielding tapes 9, 9 'from the The enlarged section “X” of the shielding band 9 'shown in FIG. 3. The shielding band 9' is supported with its supporting webs 10 'on the electrically conductive outside of the current roller 3. Only in the area of the drain grooves 11' is this edge portion of the current roller 3 in Due to the electrically non-conductive design of the shielding tape 9 ', however, this area of the current roller 3 is electrically shielded so that electrolytic coating of these edge sections is prevented. The shielding tape 9' is brought into contact with the outside of the current using suitable tensioning means. roller 3. There is therefore sliding contact between the top of the current roller 3 and the shielding band 9 '. The shielding bands 9, 9' are supported in the direction of rotation 4 of the current roller 3 at the end by a stop.

On the outside, the shielding band 9 'is supported on the anode holder 24 accommodated in the supporting wall 5, the shielding band 9' having a slidingly sealed contact for its ability to be set up in the longitudinal direction of the current roller 3. The anode A is held in the anode holder 24.

In a further embodiment, not shown, it is provided that the shielding tapes 9, 9 'are pressed against the surface of the current roller 3 with pressure means which are supported on the anode holder 24. An inflatable tube, for example, can be provided as such pressure medium.

The side of the shielding tape 9 'facing the metal tape 15 carries a shoulder 25', the height of which is adapted to the thickness of the metal tape 15 to be received. Through the shoulder 25 ', a projection 26' is formed, which projects on the outside over the outer edge region of the metal strip 15. Due to the protrusion 26 'projecting over the metal strip 15, a coating of the outermost edge region of the metal strip is reduced to a layer thickness of zero up to the strip edge, so that the current roller is not coated outside of the useful region N.

From the arrangement of the shielding tape 9 'it is clear that with this an effective electrical shielding of the metal tape 15th Covered areas of the current roller 3 is achieved without means to provide a liquid seal to keep the electrolyte away from this area. In particular, it is clear from FIG. 3 that the metal strip 15 is guided freely in the shoulder 25 ', without contact with the shielding strip 9'.

FIG. 4 shows the coating device 1, the coating device 1 now being set up for the production of electrolytic metal strips. A metal strip to be coated is therefore not supplied via the deflection roller 16. In the event of a current flow, a metallic coating deposits on the cylindrical surface of the current roller 3, which is pulled off in the area of the current roller 3 emerging from the spacing space 6 by the rotation of the current roller 3 via the deflection roller 17. The metal strip 28 produced in this way can then be continuously fed to a further processing or rolled up for intermediate storage. For this purpose, the surface of the current roller 3 is conditioned in such a way that it is ensured that the metallic coating which forms on the current roller surface adheres only slightly and can therefore be removed easily.

To set the desired width of the metal strip to be produced, the shielding strips 9, 9 'are set up in such a way that the useful area N of the current roller corresponds to the width of the metal strip 28 to be produced. Due to the possibility of setting up the shielding tapes 9, 9 ', the device 1 is suitable for producing metal tapes of different widths.

It is clear from the illustrated exemplary embodiments that the coating device 1 is suitable, without making changes, both for the one-sided electrolytic coating of metal strips and for the actual production of metal strips by means of electrolysis. The variability with regard to the ability to be set up via the shielding tapes 9, 9 ′ enables the device 1 to be used universally. Compilation of the reference symbols

1 coating device

Tub

3 current roller

arrow

5 retaining wall

6 clearance space

7 Electrolyte supply

8 arrow

9, 9 'shielding tape

10, 10 'support web

11, 11 'drain groove

12, 12 'collectors

13 outlet

14 arrow

15 metal band

16 deflection roller

17 pulley

18, 18 'adjusting device

19, 19 'retaining bridge

20, 20 'recording

21, 21 'receiving piece

22, 22 'drain opening

23 center line

24 anode holder

25 'paragraph

26 'advantage

27 'marginal gap

28 metal band

A anode

N Usable area of the current roller

Claims

claims

1. Device for performing continuous electrolytic deposition processes comprising a rotating cathodic

Current roller (3) with a surface that is electrically conductive over its entire usable width and one or more anodes (A) which are spaced approximately concentrically to the current roller (3), the spacing space (between the current roller (3) and the anode (A)) 6) is flowed through by an electrolyte containing the metal to be deposited in dissolved form, to which current roller (3) in a peripheral arrangement are assigned means for preventing a coating of the areas which are not used in electrolytic deposition processes from the current roller (3), characterized in that the current roller ( 3) one on each side

The end face, which projects beyond the cylindrical surface of the current roller (3), is assigned a shielding tape (9, 9 ') made of an electrically insulating material which is located between the cathodic current roller (3) and the anode (s) and adjacent to that of the current roller electrolytic deposition processes used

Area (useful area) (N), which electrically shields the edge area of the current roller (3) that is not used in the deposition process and surrounds the current roller (3) at least at the fill level of the electrolyte, the side of a shielding tape facing the useful area (N) (9, 9 ') has a shoulder (25') pointing in this direction and extending over the length of the shielding tape (9, 9 ').

2. Device according to claim 1, characterized in that a shielding tape (9, 9 ') with its side facing away from the useful area (N) is arranged projecting beyond the lateral end face of the current roller (3).

3. Apparatus according to claim 1 or 2, characterized in that the shielding tape (9, 9 ') is supported on the surface of the current roller (3) to be shielded.

4. The device according to claim 3, characterized in that the shielding tape (9, 9 ') on its side facing the current roller (3) side transversely to the length of the support webs (10, 10') and alternately arranged with these drain grooves (11, 11 ' ) having.

5. Device according to one of claims 2 to 4, characterized in that the drain grooves (1 1, 1 1 ') in the region of their outlet openings (22, 22').

6. Device according to one of claims 1 to 5, characterized in that the shielding tape (9, 9 ') is sealed on the outside on a receptacle (24) for holding the anodes (A).

7. The device according to one or more of claims 2 to 6, characterized in that each shielding tape (9, 9 ') on its end over the current roller (3) protruding side has retaining means (19, 19') with an adjusting device ( 18, 18 ') for setting up the shielding tapes (9, 9') with respect to the width of the current roller edge to be shielded in engagement.

8. The device according to claim 7, characterized in that the

Adjusting device (18, 18 ') comprises a partially annular receiving piece (21, 21'), in the side facing the current roller (3), a receiving groove (20, 20 ') for receiving the outer edge of the shielding tape (9, 9') with its Retaining means (19, 19 ') is arranged, which receiving piece (21, 21') is arranged in the axial direction of the current roller (3).

9. The device according to claim 8, characterized in that an adjusting device (18, 18 ') for axially setting up a receiving piece (21, 21') comprises two piston-cylinder arrangements.

10. The device according to claim 7, characterized in that the retaining means are webs (19, 19 ') which are arranged at intervals from each other in the longitudinal direction of the shielding tape (9, 9') on its outer edge projecting from the band surface.

11. The device according to one or more of claims 1 to 10, characterized in that the side facing each current shielding tape (9, 9 ') facing the current roller (3) is coated with friction reducing at least in the region of the sections contacting the current roller (3).