Chemistry: electrical and wave energy – Apparatus – Electrolytic
Reexamination Certificate
1998-09-11
2001-03-06
Valentine, Donald R. (Department: 1741)
Chemistry: electrical and wave energy
Apparatus
Electrolytic
C204S222000, C204S273000
Reexamination Certificate
active
06197169
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an apparatus for electroplating a rotogravure cylinder using ultrasonic energy.
BACKGROUND OF THE INVENTION
In a conventional apparatus for the electroplating of a rotogravure printing cylinder, it is customary to rotate the cylinder (electrically charged as a cathode) in a tank filled with an electrolyte bath and copper bars or copper nuggets (electrically charged as an anode), as disclosed in U.S. Pat. No. 4,352,727 issued to Metzger, and incorporated by reference herein (wherein the copper nuggets are supported in a set of baskets made of titanium or of a plastic material and disposed around each side of the cylinder), or simply a plating solution.
In the arrangement shown in U.S. Pat. No. 4,352,727, the top edge of the respective baskets are disposed below the surface of the electrolyte bath so as to ensure free circulation of constantly refreshed (i.e. filtered) electrolytic fluid or solution. Electrolytic fluid is pumped into the tank from a manifold adjacent to the bottom of one of the baskets, in the direction of cylinder rotation. The top of the rotating cylinder to be plated is disposed slightly above the surface level of the electrolytic fluid so that a washing action occurs as the surface of the cylinder breaks across the surface of the electrolyte. Ions move from the copper bars or nuggets through the electrolytic fluid to the surface of the rotating cylinder during the plating process (or in the reverse direction in the deplating process). Where plating is done directly from a plating solution, ions moves directly from the solution to the surface of the rotating cylinder.
Over time, refinements of this system have facilitated satisfactory control of the plating process, to achieve the desirable or necessary degree of consistent plating and uniformity in the plated surface of the cylinder. However, the complete process is comparatively slow, and extra polishing steps may be necessary after plating in order to produce a desirable uniform surface (e.g. roughness on grain structure) on the cylinder. According to the known arrangement, the overall efficiency of the process necessary to produce a suitably uniform plated surface on the cylinder can be adjusted either by reducing the current density, which increases the plating time but reduces the number or duration of additional polishing steps, or by increasing the current density, which reduces the plating time but increases the number or duration of additional polishing steps.
Furthermore, in the known arrangement, during operation, a copper sludge may tend to accumulate on and about the cylinder during the plating process, forming uneven and undesirable copper deposits, typically in areas of low current density (such as furthest apart from the copper cylinder). A copper sludge may also build up between the contact surfaces of the titanium baskets or lead contacts. Moreover, other surfaces may become fouled with sludge and other matter.
Ultrasonic wave energy has been used successfully in surface cleaning applications. The long-known advantages in using ultrasonic energy in electroplating have also been described in such articles as “Ultrasonics in the Plating Industry”,
Plating
, pp. 141-47 (August 1967), and “Ultrasonics Improves, Shortens and Simplifies Plating Operations,”
MPM
, pp. 47-49 (March 1962), both of which are incorporated by reference herein. It has been learned that ultrasonic energy may advantageously be employed to improve the quality (e.g. uniformity and consistency of grain structure) of a plating process by providing for uniformity and efficiency of ion movement. In other applications, it has been found that copper can be plated onto a surface in a production system using ultrasonic energy at up to four times the rate ordinarily possible. It has also been found that the use of ultrasonic energy in an electroplating process provides an increase in both the anode and cathode current efficiency, and moreover, the practical benefit of faster plating with less hydrogen embrittlement (e.g. with less oxidation of the hydrogen on the plating and deplating surfaces).
Accordingly, it would be advantageous to have an apparatus configured to capitalize on the advantages of ultrasonic energy in the electroplating of a rotogravure cylinder. It would also be advantages to have an apparatus configured to use ultrasonic energy in the plating a rotogravure cylinder in order to obtain a more uniform and consistent grain structure on the plated surface of the cylinder through a more efficient process. It would further be advantageous to have a rotogravure cylinder plating apparatus employing ultrasonic energy to eliminate the build-up of copper (or other) sludge during the plating process.
SUMMARY OF THE INVENTION
The present invention relates to an apparatus and method for electroplating and deplating a rotogravure cylinder out of a plating solution. The apparatus includes a plating tank adapted to rotatably maintain the cylinder and to contain a plating solution so that the cylinder is at least partially disposed into the plating solution, a mounting structure mountable within the tank partially on each side of and generally below the cylinder, and a plurality of conductors at least partially disposed within the plating solution. A current source is electrically connected to the conductors and to the cylinder. An ultrasonic system introduces wave energy into the plating solution. The ultrasonic system includes at least one transducer element mountable within the tank and a power generator adapted to provide electrical energy to the at least one transducer element. The at least one ultrasonic transducer element is protected from effects of the plating solution by a protective cover.
REFERENCES:
patent: 2702260 (1955-02-01), Massa
patent: 3351539 (1967-11-01), Branson
patent: 3647646 (1972-03-01), Tucker et al.
patent: 3923610 (1975-12-01), Bergin et al.
patent: 3933601 (1976-01-01), Ishibashi et al.
patent: 4352727 (1982-10-01), Metzger
patent: 4503769 (1985-03-01), Andersen
patent: 4812219 (1989-03-01), Sattrup et al.
patent: 4830758 (1989-05-01), Bodine
patent: 5409594 (1995-04-01), Al-Jiboory et al.
patent: 5707438 (1998-01-01), Carlton
patent: 5925231 (1999-06-01), Metzger
patent: 41 13 361 (1990-04-01), None
patent: 0 248 118 A1 (1986-12-01), None
H.E. Ricks, “Ultrasonics Improves, Shortens, and Simplifies Plating Operations,” MPM, pp. 47-49 (Mar. 1962) Best Available Copy.
W.D. Mogerman, “Ultrasonics in the Plating Industry,” Plating, pp. 941-947 (Aug. 1967) Best Available Copy.
Electroplating Engineering Handbook (Van Nostrand Reinhold Company, A. Kenneth Graham, ed. 1971) pp. 165-166 (No Month).
Ultrasonics General Information (printed from Internet on Nov. 14, 1996; dated Mar. 18, 1995, 3 pages total).
Maurice O'Donoghue, The Ultrasonic Cleaning Process (printed from Internet on Nov. 14, 1996; dated Mar. 6, 1996, 6 pages total).
J.R. Cox, “The Impact of Electromechanical Engraving Specifications on Streaking and Hazing,” Gravure, pp. 12-15 (Winter 1994) Best Available Copy No specific month available.
R. Martin AG brochure entitled “Plating installations type B” (selected pages) (no date), 4 pages total.
Dixon Ticonderoga Company, “Grapho Kote No. 4 Ladle Coating,” Product Data Sheet Pds—G332, 1 page (no date).
Crest Ultrasonics Corporation, “Martin Walter Push-Pull™ Transducers” Technical Specifications (2 pages, no date).
Foley & Lardner
Valentine Donald R.
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