Method and apparatus for electrochemical processing

• US 6,149,781 A
• Filed: 10/21/1997
• Issued: 11/21/2000
• Est. Priority Date: 01/10/1994
• Status: Expired due to Fees

• Current Assignee: Klehr Harrison Harvey Branzburg, LLP
• Original Assignee: James L. Forand
• Inventors: Forand, James L.
• Primary Examiner(s): Gorgos, Kathryn
• Assistant Examiner(s): SMITH HICKS, ERICA D
• Application Number:
  US08/955,386
• Time in Patent Office: 1,127 Days
• Field of Search: 204/412, 204/199, 204/239, 205/138, 205/660
• US Class Current: 204/239
• CPC Class Codes: C25D 7/0621 In horizontal cells
• CPC Class Codes: C25F 1/00 Electrolytic cleaning, degreasing, pickling or descaling
• CPC Class Codes: C25F 7/00 Constructional parts, or assemblies thereof, of cells for electrolytic removal of material from objects for both electrolytic coating and removal C25D; Servicing or operating

Abstract

A continuous strip is electrochemically processed in an electrolytic processing bath using either a thin flexible or resilient dielectric wiping blade or an open web, plastic mesh to wipe bubbles of gas from the surface, sever dendritic material, if such is present, and to remove a surface layer of partially depleted electrolytic solution in the form of a barrier or depletion layer including a heat zone, replacing with fresh cooler solution and to stabilize strip portions extending between support rolls. The resilient dielectric wiper blade is preferably used with perforated anodes which allow fresh electrolytic solution to flow into the space between the anodes and the strip surface after being expelled by passage of the strip past the wiping blade. It may also be used with electrode baskets in electroplating, however. The open web, plastic mesh wiper is particularly effective as a separator to provide the best spacing between the strip and the electrodes to prevent arcing and also prevents any filter cloth used over the electrodes in electroplating from catching upon the strip. The resilient wiper blade and open web, plastic mesh are preferably used in combination, but may also be used separately in electroplating, anodizing or electrolytic cleaning.

Claims

1. An improved arrangement for electrolytic cleaning of an elongated flexible metallic substrate in a heated alkaline cleaning bath comprising:

(a) means to pass a longitudinally extended metallic workpiece having at least one surface to be cleaned through a containment means for a body of alkaline electrolytic solution to which solution the surface to be cleaned is exposed,

(b) means to heat and maintain the electrolytic or electrochemical cleaning solution at an elevated temperature,

(c) at least one electrode mounted closely adjacent the pass line of said metallic workplace within the containment means,

(d) at least one unitary dielectric surface contact separating means extending at least transversely across the surface to be cleaned of said longitudinally extended metallic workplace and having a height measured perpendicular to the workplace surface greater than the arcing distance between the workplace and the electrode,

(e) said dielectric surface contact separating means being compatible with an alkaline electrolytic solution and having a heat deflection temperature exceeding the elevated temperature of the electrolytic cleaning solution.

2. An improved arrangement in accordance with claim 1 wherein the dielectric surface contact separating means is a thin elongated dielectric surface contact means extending transversely across the workpiece surface.

3. An improved arrangement in accordance with claim 1 wherein the dielectric surface contact separating means is an open-web, plastic mesh positioned between the workpiece surface and the electrode.

4. An improved arrangement in accordance with claim 3 wherein the open-web, plastic mesh is formed of polysulfone plastic resin.

5. An improved arrangement in accordance with claim 3 wherein the open-web, plastic mesh is formed of polyvinylidene plastic resin.

6. An improved arrangement in accordance with claim 2 wherein the elongated dielectric surface contact means is formed from polysulfone plastic material.

7. An improved arrangement in accordance with claim 2 wherein the elongated dielectric surface contact means is formed of polyvinylidene.

8. An improved arrangement in accordance with claim 2 wherein the elongated dielectric surface contact means is biased toward the elongated workpiece surface by gravity.

9. An improved arrangement in accordance with claim 2 wherein the elongated dielectric surface contact means is biased toward the elongated workpiece surface by resilient means arranged to effect such biasing.

10. An improved arrangement in accordance with claim 2 additionally comprising

(f) a dielectric separating means comprised of open-web, plastic mesh spaced between the electrode and the elongated workpiece on at least one side of the thin elongated dielectric surface contact measured along the workpiece surface.

11. An improved arrangement for electrolytic cleaning in accordance with claim 10 wherein both the thin elongated dielectric surface contact means and the open-web, plastic mesh separator have a heat deflection temperature greater than the boiling point of water.

12. An improved arrangement for electrolytic cleaning in accordance with claim 11 wherein both the elongated dielectric surface contact means and the open-web, plastic mesh separator are formed of a polysulfone plastic resin.

13. An improved arrangement for electrolytic cleaning in accordance with claim 11 wherein both the elongated dielectric surface contact means and the open-web, plastic mesh separator are formed of polyvinylidene.

14. An improved arrangement for electrolytic cleaning in accordance with claim 11 wherein there are multiple electrodes spaced along the longitudinally extended workpiece on both sides and

(g) said electrodes are arranged in pairs across from each other on opposite sides of the elongated workpiece which has two opposite surfaces to be cleaned with one electrode of each pair being spaced significantly closer to the elongated workpiece than the other, the respective close electrode and farther electrode alternating from one side of the workpiece to the other from one pair to the next along the extent of the elongated workpiece.

15. An improved arrangement for electrolytic cleaning in accordance with claim 14 in which the more closely spaced electrodes with respect to the elongated work piece are provided with one or more thin elongated dielectric surface contact means between the electrode and the workpiece.

16. An improved arrangement for electrolytic cleaning in accordance with claim 11 wherein each of the electrodes is provided with an open-web, plastic mesh between the surface of the electrode at the workpiece.

17. An improved arrangement for electrolytic cleaning in accordance with claim 14 wherein the electrodes nearer the workpiece are provided with intermediate elongated wiping means, with respect to the workpiece, and the electrodes spaced farther from the workpiece are provided with open-web, plastic mesh separators positioned between the electrodes and the workpiece.

18. An improved arrangement for electrolytic cleaning in accordance with claim 14 wherein the elongated dielectric wiping means and the open-web, plastic mesh are formed from polysulfone plastic resin.

19. A arrangement in accordance with claim 12 wherein the open-web, plastic mesh separators have been fabricated by mechanical forming means.

20. An improved arrangement for electrochemical processing of an elongated flexible metallic substrate in an electrolytic bath comprising:

(a) means to pass a longitudinally extended metallic workpiece having at least one surface to be processed through a containment means for a body of electrolytic solution to which solution the surface to be processed is exposed,

(b) at least one electrode mounted closely adjacent the pass line of said metallic workpiece within the containment means,

(c) at least one unitary dielectric surface contact separating means extending at least transversely across the surface to be processed of said longitudinally extended metallic workpiece and having a height measured perpendicular to the workpiece surface greater than the arcing distance between the workpiece and the electrode,

(d) said dielectric surface contact separating means taking the form of an open web, plastic mesh having its outer surface spaced a distance from the electrode surface greater than the arcing distance and

(e) said dielectric surface contact separating means being compatible with an electrolytic solution and having a heat deflection temperature exceeding the elevated temperature of the electrolytic solution.

21. An improved arrangement for electrochemical processing in accordance with claim 20 wherein the electrochemical processing is an electrolytic cleaning operation.

22. An improved arrangement for electrochemical processing in accordance with claim 20 wherein the electrochemical processing is an electroplating operation.

23. An improved arrangement for electrochemical processing in accordance with claim 20 wherein the electrochemical processing is an anodizing operation.

24. An improved arrangement for electrochemical processing in accordance with claim 20 wherein the open web, plastic mesh has webs between the openings which are wider than they are high.

25. An improved arrangement for electrochemical processing in accordance with claim 20 wherein the open web, plastic mesh has webs between the openings which are higher than they are wide.

26. An improved arrangement for electrochemical processing in accordance with claim 20 wherein the open web, plastic mesh is combined with a thin elongated wiping blade.

27. An improved arrangement for electrochemical processing in accordance with claim 20 wherein the amount of open space versus web material in the mesh is no less than 25% open and 75% solid and no more than 95% open and 5% solid.

28. An improved arrangement for electrochemical processing in accordance with claim 27 in which the openings in the mesh are between one quarter to two inches in diameter and more or less equidimensional.

29. An improved arrangement for electrochemical processing of an elongated flexible metallic substrate in an electrolytic cleaning bath comprising:

(a) means to pass a longitudinally extended metallic workpiece having at least one surface to be cleaned through a containment means for a body of electrolytic cleaning solution to which solution the surface to be processed is exposed,

(b) at least one electrode mounted closely adjacent the pass line of said metallic workpiece within the containment means,

(c) means to heat and maintain the electrolytic cleaning solution at an elevated temperature,

(d) at least one unitary dielectric surface contact separating means extending transversely across the surface to be processed of said longitudinally extended metallic workpiece and having an effective height measured perpendicular to the workpiece surface greater than the arcing distance between the workpiece and the electrode,

(e) said dielectric surface contact means having a heat deflection temperature exceeding the elevated temperature of the electrolytic cleaning solution and taking the form of an open web, plastic mesh having its outer surface spaced a distance from the electrode surface greater than the arcing distance, and

(f) wherein the open web, plastic mesh has webs between the openings which are wider than they are high.

30. An improved arrangement for electrochemical processing of an elongated flexible metallic substrate in an electrolytic cleaning bath comprising:

(a) means to pass a longitudinally extended metallic workplace having at least one surface to be cleaned through a containment means for a body of electrolytic cleaning solution to which solution the surface to be processed is exposed,

(b) at least one electrode mounted closely adjacent the pass line of said metallic workplace within the containment means,

(c) means to heat and maintain the electrolytic cleaning solution at an elevated temperature,

(d) at least one unitary dielectric surface contact separating means extending transversely across the surface to be processed of said longitudinally extended metallic workplace and having an effective height measured perpendicular to the workplace surface greater than the arcing distance between the work piece and the electrode,

(e) said dielectric surface contact means having a heat deflection temperature exceeding the elevated temperature of the electrolytic cleaning solution and taking the form of an open web, plastic mesh having its outer surface spaced a distance from the electrode surface greater than the arcing distance, and

(f) wherein the open web, plastic mesh has webs between the openings which are higher than they are wide.

31. An improved arrangement for electrochemical processing of an elongated flexible metallic substrate in an electrolytic cleaning bath comprising:

(a) means to pass a longitudinally extended metallic workplace having at least one surface to be cleaned through a containment means for a body of electrolytic cleaning solution to which solution the surface to be processed is exposed,

(b) at least one electrode mounted closely adjacent the pass line of said metallic workplace within the containment means,

(c) means to heat and maintain the electrolytic cleaning solution at an elevated temperature,

(d) at least one unitary dielectric surface contact separating means extending at least transversely across the surface to be processed of said longitudinally extended metallic workplace and having an effective height measured perpendicular to the workplace surface greater than the arcing distance between the workpiece and the electrode,

(e) said dielectric surface contact means having a heat deflection temperature exceeding the elevated temperature of the electrolytic cleaning solution and taking the form of an open web, plastic mesh having its outer surface spaced a distance from the electrode surface greater than the arcing distance, and

(f) wherein the open web, plastic mesh is combined with a thin elongated wiping blade.