US3989604A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing metal strip having a galvanized coating on one side
Assignee: National Steel Corp
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Filing: 1975-10-15
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Granted: 1976-11-02
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Expires: 1995-10-15
Abstract
Abstract A method for producing galvanized metal sheet or strip material having a zinc coating on one side only. The method includes utilizing the strip as a bipolar electrode and electrolytically removing a zinc coating from one side of the strip while simultaneously depositing a substantially equivalent amount of zinc on the opposite side of the strip. The method is most economically performed with a steel strip having a differential coating of zinc.
Inventors
- 👤 Lowell W. Austin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:33
CPC Classifications
C; C25; C25D; C25D7/00; C25D7/06; C25D7/0614; C25D7/0671; C25D3/00; C25D3/02; C25D3/22; C25D5/00; C25D5/02; C25D5/028; Y; Y10; Y10S; Y10S204/00; Y10S204/07
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
65 words
A method for treating zinc-coated metal strip material comprising: a. immersing the strip in an electrolyte solution, b. passing the strip through the electrolyte solution and between anode means and cathode means, and c. electrolytically removing a zinc coating from the side of the strip facing the cathode means while simultaneously depositing a substantially equivalent amount of zinc on the opposite side of the strip.
Claim 2
Independent Claim
65 words
A method for treating zinc-coated metal strip material comprising: a. immersing the strip in an electrolyte solution, b. passing the strip through the electrolyte solution and between anode means and cathode means, and c. electrolytically removing a zinc coating from the side of the strip facing the cathode means while simultaneously depositing a substantially equivalent amount of zinc on the opposite side of the strip.
Claim 3
Dependent Claim
23 words
A method as defined in claim 1 wherein the strip passing between the anode means and the cathode means is a bipolar electrode.
Claim 4
Dependent Claim
51 words
A method as defined in claim 2 wherein the strip has a zinc coating on a first side which is less than the zinc coating on the opposite side, said first side of the strip facing the cathode means as the strip passes between the cathode means and the anode means.
Claim 5
Dependent Claim
38 words
A method as recited in claim 3 wherein the zinc coating on the first side is about 0.01 - 0.15 ounce/ft 2 and the zinc coating on the opposite side is about 0.2 - 0.7 ounce/ft 2 .
Claim 6
Dependent Claim
36 words
A method as recited in claim 4 wherein the electrolytic solution is an aqueous solution of zinc sulfate and sulfuric acid and contains from about 10 to 20 ounces of zinc metal per gallon of solution.
Claim 7
Dependent Claim
20 words
A method as recited in claim 5 wherein the electrolyte solution has a pH of from about 1 to 4.
Claim 8
Dependent Claim
25 words
A method as recited in claim 6 wherein the electrolyte solution is maintained at a temperature within the range of from 120° to 150° F.
Claim 9
Dependent Claim
24 words
A method as recited in claim 3 wherein the spacing between the strip and each electrode means is from about 1 to 3 inches.
Claim 10
Dependent Claim
29 words
A method as recited in claim 8 wherein the average current density on the strip opposite the cathode means ranges from about 200 to about 1,000 amps/ft 2 .
Claim 11
Dependent Claim
39 words
A method as recited in claim 3 wherein the anode means and cathode means are arranged in a substantially diagonal configuration and the strip is passed between the anode means and cathode means also along a substantially diagonal line.
Claim 12
Dependent Claim
19 words
A method as recited in claim 10 wherein the anode means and cathode means comprise two sets of electrodes.
Claim 13
Dependent Claim
49 words
A method as recited in claim 3 wherein subsequent to the electrolytic removal of the zinc coating from the first side of the strip, the first side is subjected to a brushing treatment which does not scar the surface of the strip whereby any residual loose coating is removed.
Claim 14
Dependent Claim
36 words
A method as recited in claim 2 wherein the electrolyte solution is an aqueous solution of zinc sulfate and sulfuric acid and contains from about 10 to 20 ounces of zinc metal per gallon of solution.
Claim 15
Dependent Claim
20 words
A method as recited in claim 13 wherein the electrolyte solution has a pH of from about 1 to 4.
Claim 16
Dependent Claim
26 words
A method as recited in claim 14 wherein the electrolyte solution is maintained at a temperature within the range of from about 120° to 150° F.
Claim 17
Dependent Claim
39 words
A method as recited in claim 2 wherein the anode means and cathode means are arranged in a substantially diagonal configuration and the strip is passed between the anode means and cathode means also along a substantially diagonal line.
Claim 18
Dependent Claim
19 words
A method as recited in claim 16 wherein the anode means and cathode means comprise two sets of electrodes.
Claim 19
Dependent Claim
47 words
A method as recited in claim 2 wherein subsequent to the electrolytic removal of the zinc coating from one side of the strip, the strip is subjected to a brushing treatment which does not scar the surface of the strip, whereby any residual loose coating is removed.
Claim 20
Dependent Claim
28 words
A method as recited in claim 1 wherein the cathode means is of a material which resists the plating of metal ions tending to discharge on its surface.
Claim 21
Dependent Claim
30 words
A method as recited in claim 1 wherein the cathode means is of a material on which zinc will deposit but from which a zinc plating can be easily stripped.
Claim 22
Dependent Claim
29 words
A method as recited in claim 20 wherein the cathode means comprises a material selected from the group consisting of lead, lead alloys, carbon, platinum plated titanium and aluminum.
References Cited (Backward Citations)
US1798391A
Cited
US2655473A
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US2673836A
Cited
US3178305A
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US3429787A
Cited
US3901771A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-02 | 1980-05-03 | 1980-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-02 | 1984-05-03 | 1984-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-02 | 1988-05-03 | 1988-11-02 | $7700.00 | Window Closed / Lapsed |