Patent Publication Number: US-7914658-B2

Title: Electroplating apparatus

Description:
RELATED APPLICATIONS 
     This application is a division of application Ser. No. 10/852,597 filed May 24, 2004, now U.S. Pat. No. 7,556,722, which is a continuation-in-part of application Ser. No. 09/992,205 filed Nov. 6, 2001, now U.S. Pat. No. 6,929,723, incorporated by reference herein which is a continuation-in-part of application Ser. No. 09/528,393, titled “Electroplating Apparatus Having a Non-Dissolvable Anode,” filed Mar. 20, 2000, now U.S. Pat. No. 6,547,936, incorporated by reference herein, which is in turn a continuation in-part of application Ser. No. 09/345,263, titled “Electroplating Apparatus,” filed Jun. 30, 1999, issued as U.S. Pat. No. 6,231,728 on May 15, 2001, incorporated by reference herein, which is in turn a continuation-in-part of application Ser. No. 09/151,317, titled “Apparatus for Electroplating Rotogravure Cylinder Using Ultrasonic Energy,” filed Sep. 11, 1998, now U.S. Pat. No. 6,197,169 incorporated by reference herein, which is in turn a continuation-in-part of application Ser. No. 08/939,803, titled “Apparatus and Method for Electroplating Rotogravure Cylinder Using Ultrasonic Energy,” filed Sep. 30, 1997, issued as U.S. Pat. No. 5,925,231 on Jul. 20, 1999, incorporated by reference herein, which is in turn a continuation-in-part of application Ser. No. 08/854,879, titled “Rotogravure Cylinder Electroplating Apparatus Using Ultrasonic Energy,” filed May 12, 1997, now abandoned, incorporated by reference herein, which is in turn a continuation-in-part of application Ser. No. 08/755,488, titled “Apparatus for Electroplating Rotogravure Cylinders Using Ultrasonic Energy,” filed Nov. 22, 1996, now abandoned, incorporated by reference herein. 
    
    
     BACKGROUND 
     In a conventional electroplating apparatus, it is customary to bathe an object to be plated (electrically charged as a cathode) in a tank filled with a plating solution (i.e., electrolyte fluid) and metallic bars or metallic nuggets (electrically charged as an anode), supported in a set of baskets made of titanium or of a plastic material and disposed around each side of the object (e.g., a rotogravure printing cylinder). 
     In an arrangement for plating a rotogravure cylinder, shown in U.S. Pat. No. 4,352,727 issued to Metzger, and incorporated by reference herein, the metallic bars or metallic nuggets are disposed below the surface of the plating solution. Ions move from the metallic bars or metallic nuggets through the plating solution to the surface of the cylinder (preferably rotating) during the plating process (or in the reverse direction in the deplating process). Where plating is done directly from a plating solution, ions move 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 an object, particularly in the case of a rotogravure cylinder. However, the complete process is comparatively slow, and extra polishing steps are typically necessary after plating in order to produce a desirable uniform surface (e.g., consistent grain structure) on the object. According to the known arrangement, the overall efficiency of the process necessary to produce a suitably uniform plated surface on an object 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. 
     One of the causes of an undesirable plated surface is that in the known arrangement, during operation a metal sludge, formed from metal displaced from the metallic bars, nuggets or anode, tends to accumulate on and about the object during the plating process, forming uneven and undesirable deposits (typically in areas of low current density). These uneven depositions caused by the sludge necessitates an increased number or longer duration of additional polishing steps. The sludge may also build up between the contact surfaces of the baskets or anodes which may affect the efficiency of the plating process. Other surfaces of the electroplating apparatus may also become fouled with sludge and other matter. 
     Another method of reducing the effects of the sludge is to expose the object and at least portions of the electroplating apparatus to ultrasonic energy throughout at least a portion of the plating process as described in U.S. Pat. No. 5,925,231 issued to Metzger, incorporated by reference herein. 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 electroplating apparatus configured to capitalize on the advantages of substantially removing or eliminating material that is vulnerable to chemical attack or dissolution in the plating solution (or adequately protecting any material that cannot be removed), to prevent the buildup of sludge during the plating process, thereby reducing the number or duration of additional polishing steps. It would also be advantageous to have an electroplating apparatus employing an anode that is not vulnerable to chemical attack or dissolution by the plating solution (e.g., a non-dissolvable anode), for example, by substantially employing non-dissolvable materials (or adequately protecting any material that is not non-dissolvable), and thereby reducing or eliminating material that acts as the source of the sludge, so that the build-up of sludge during the plating process will be substantially reduced or eliminated and a more uniform and consistent grain structure on the plated surface of the object will be obtained. It would further be advantageous to have an apparatus configured to combine the advantages of implementing a non-dissolvable anode with the advantages of ultrasonic energy in plating an object (e.g., a rotogravure cylinder) in order to substantially reduce or eliminate the build-up of metal sludge during the plating process and obtain a more uniform and consistent grain structure on the plated surface of the object through a more efficient process. 
     It would be desirable to provide a method and apparatus providing some or all of these and other advantageous features. 
     SUMMARY 
     One embodiment relates to an apparatus for electroplating a rotogravure cylinder out of a plating solution. The apparatus includes a plating tank adapted to support the object and to contain the plating solution so that the object is at least partially disposed into the plating solution, and an anode system which includes at least one anode at least partially disposed within the plating solution. The cylinder and anode system both connectable to a current source. The apparatus further includes an ultrasonic system that introduces wave energy into the plating solution. The ultrasonic system includes at least one transducer element mountable within the plating tank to the mounting structure and a power generator adapted to provide electrical energy to the at least one transducer element. 
     Another embodiment relates to an apparatus for electroplating a rotogravure cylinder out of a plating solution. The apparatus includes a plating tank adapted to rotatably maintain the cylinder and to contain the plating solution so that the cylinder is at least partially disposed into the plating solution, and an anode system having at least one anode at least partially disposed within the plating solution. The anode includes a conductive core, a first layer including titanium securely applied to the conductive core and a second layer including at least one platinum-group metal or platinum-group metal oxide and at least one valve metal or valve metal oxide. The cylinder and anode system both connectable to a current source. 
     An additional embodiment relates to an apparatus for electroplating a rotogravure cylinder out of a plating solution. The apparatus includes a plating tank adapted to rotatably maintain the cylinder and to contain the plating solution so that the cylinder is at least partially disposed into the plating solution, and an anode system having at least one anode at least partially disposed within the plating solution. The anode includes a titanium core and a protective surface material that includes a mixture of iridium or iridium oxide and a valve metal or valve metal oxide. They cylinder and anode system both connectable to a current source. The apparatus further includes an ultrasonic system that introduces wave energy into the plating solution. The ultrasonic system includes at least one transducer element mountable within the plating tank to the mounting structure and a power generator adapted to provide electrical energy to the at least one transducer element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic sectional elevation view of an electroplating apparatus for plating a rotogravure cylinder according to an embodiment utilizing a non-dissolvable anode. 
         FIG. 2  is a sectional side and elevation view of the plating tank (with a rotogravure cylinder). 
         FIG. 3  is a schematic elevation view of a conventional printing system. 
         FIG. 4  is a schematic perspective view of a system for engraving an image on a rotogravure-cylinder. 
         FIG. 5  is a schematic sectional elevation view of a lifter for the apparatus of  FIG. 1 . 
         FIG. 6  is a schematic sectional end elevation view of an apparatus for plating a rotogravure cylinder according to an embodiment employing a non-dissolvable anode. 
         FIG. 7  is a fragmentary perspective view of a conductor having a generally rectangular cross-section. 
         FIG. 8  is a fragmentary perspective view of the non-dissolvable anode of  FIG. 6 . 
         FIG. 9  is a schematic sectional elevation view of an electroplating apparatus for plating a rotogravure cylinder according to an embodiment utilizing a dosing tank and an alternate embodiment of a non-dissolvable anode. 
         FIG. 10  is a schematic sectional end elevation view of an apparatus for plating a rotogravure cylinder according to an embodiment employing a non-dissolvable anode. 
         FIG. 11  is a fragmentary perspective view of a conductor including a conductive surface material and a non-conductive surface material. 
         FIG. 12  is a fragmentary perspective view of the non-dissolvable anode of  FIG. 10 . 
         FIG. 13  is a sectional view of the conductor of  FIG. 11  taken through line  13  showing alternate abutments of the surface material. 
         FIG. 14  is a schematic sectional end elevation view of an apparatus for plating a rotogravure cylinder according to an alternate embodiment employing a non-dissolvable anode supported from beneath. 
         FIG. 15  is a fragmentary perspective view of a conductor including a conductive surface material. 
         FIG. 16  is a fragmentary perspective view of a conductor. 
         FIG. 17  is a fragmentary perspective view of the non-dissolvable anode of  FIG. 14 . 
         FIG. 18  is a fragmentary perspective view of a non-dissolvable anode according to an alternate embodiment. 
         FIG. 19  is a fragmentary perspective view of the non-dissolvable anode according to an alternate embodiment. 
         FIG. 20  is a schematic sectional elevation view of an apparatus for plating a rotogravure cylinder according to an embodiment employing a non-dissolvable anode ring. 
         FIG. 21  is a schematic sectional elevation view of an apparatus for plating a rotogravure cylinder according to an embodiment configured to support the rotogravure cylinder in a vertical position. 
         FIG. 22  is a schematic sectional view of an electroplating apparatus for plating a rotogravure cylinder according to an embodiment utilizing a non-dissolvable anode. 
         FIG. 23  is a schematic sectional end elevation view of an apparatus for plating a rotogravure cylinder directly out of a plating solution according to an embodiment employing an alternate embodiment of a non-dissolvable anode. 
         FIG. 24  is a schematic sectional end elevation view of an apparatus for plating a rotogravure cylinder directly out of a plating solution according to an embodiment employing an additional alternate embodiment of a non-dissolvable anode. 
         FIG. 25   a  is a fragmentary perspective view of a conductor having a generally circular cross-section. 
         FIG. 25   b  is a fragmentary perspective view of a conductor having a square cross-section. 
         FIG. 25   c  is a fragmentary perspective view of a conductor having a generally rectangular cross-section. 
         FIG. 26   a  is a fragmentary perspective view of an alternate embodiment of a generally circular conductor including a plurality of conductive pieces. 
         FIG. 26   b  is a fragmentary perspective view of an alternate embodiment of a generally rectangular conductor including a plurality of conductive pieces. 
         FIG. 27  is a sectional view of the conductor of  FIG. 25   a  taken through line  27 . 
         FIG. 28  is a fragmentary perspective view of a non-dissolvable anode according to an alternate embodiment. 
         FIG. 29  is a schematic sectional end elevation view of an apparatus for plating a rotogravure cylinder according to an alternative embodiment. 
         FIG. 30  is a schematic fragmentary end elevation view of an apparatus for plating a rotogravure cylinder according to an alternative embodiment. 
         FIG. 31  is a schematic view of an ultrasonic transducer element. 
         FIG. 32  is a schematic diagram of the ultrasonic transducer system. 
         FIG. 33  is a plan view of an exemplary arrangement of ultrasonic transducer elements within a plating tank according to an alternative embodiment. 
         FIG. 34  is a schematic sectional perspective view of a plating tank showing alternative arrangements of ultrasonic transducer elements. 
         FIG. 35  is a sectional end and elevation view of the plating tank showing alternative arrangements of ultrasonic transducer elements. 
         FIG. 36  is a sectional and partial elevation view of a plating tank according to an additional alternative embodiment. 
         FIG. 37  is a schematic view of the grain structure of a rotogravure cylinder plated according to a conventional method. 
         FIG. 38  is a schematic view of the grain structure of the rotogravure cylinder plated according to a preferred embodiment. 
         FIG. 39  is a schematic sectional elevation view of an electroplating apparatus for plating a rotogravure cylinder according to an alternate embodiment employing a non-dissolvable anode. 
         FIG. 40  is a fragmentary perspective view of a conductor having a layered surface material. 
         FIG. 41  is a fragmentary perspective view of the non-dissolvable anode of  FIG. 39 . 
         FIG. 42  is a fragmentary perspective view of the plating apparatus according to one embodiment. 
         FIG. 43  is a fragmentary perspective view of the plating apparatus according to the embodiment of  FIG. 42 . 
         FIG. 44  is a fragmentary perspective view of a non-dissolvable anode according to an alternate embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , an exemplary embodiment of an apparatus for electroplating an object (shown as a rotogravure cylinder) is shown. Apparatus  110  includes plating tank  112  containing a plating solution (electrolytic fluid such as copper sulfate, or the like in an appropriate solution) indicated by reference letter F. Apparatus  110  is configured to support object  120  such that object  120  is at least partially submerged in the plating solution. Apparatus  110  further includes an anode system  128  (cathode system for deplating) that includes at least one non-dissolvable anode  130 . For plating object  120 , anode system  128  is connected to an anode side of a plating power supply (e.g., a current source of known design) and object  120  is connected to a cathode side of the power supply. For deplating, the anode-cathode connections are reversed. According to any exemplary embodiment, apparatus  110  may include at least one transducer element  150 , and a holding tank  114  as shown schematically in  FIGS. 1 ,  9  and  22 . 
     According to any exemplary embodiment, the plating apparatus is configured to plate (or deplate) an object (shown as rotogravure cylinder  120  in the FIGURES). According to  FIG. 2 , rotogravure cylinder  120  is rotatably supported at its ends (e.g., upon an extending central shaft) and is at least partially submerged into the plating solution. In plating a rotogravure cylinder, the cylinder may be rotated such that the top of the rotating cylinder is disposed slightly above the surface level of the plating solution so that a washing action occurs as the surface of the cylinder breaks across the surface of the plating solution. Accordingly, cylinder  120  is submerged to a level of approximately one-half to one-third of the cylinder diameter. In some embodiments, plating apparatus  110  is configured such that cylinder  120  is at least about 65 to 70% submerged. According to alternate embodiments, the cylinder may be fully submerged. 
     As shown in  FIG. 1 , cylinder  120  is rotatably supported at its ends by bearings within a journal  122 , in which it is rotatably driven by a suitable powering device (not shown). According to one embodiment, a rate of rotation for cylinder  120  can have a value of 120 to 220 revolutions per minute (rpm). In other embodiments, the rate of rotation can have a value of 150 to 200 rpm. The direction of the cylinder rotation may depend on the exact design of the plating apparatus. For example, as shown in  FIG. 39 , the cylinder suitably rotates in a clockwise direction. 
     Cylinder  120 , shown in  FIGS. 1 ,  5 , and  39  may be one of a standard size (e.g., having a diameter of approximately 800 to 1500 mm), or, according to alternative embodiments, cylinders of other diameters may be accommodated. Cylinder  120  may be one of a common or standard length for a particular application (e.g., having a length of approximately 40 cm to 4 m), or, according to alternative embodiments, cylinders of other lengths may be accommodated. According to any exemplary embodiment, the cylinder mounting and drive system is of a conventional arrangement known to those of ordinary skill in the art of rotogravure cylinder plating. 
     As shown in  FIG. 2 , cylinder  120  has a cylindrical face surface  120   a  and opposing axial ends  120   b  (having a generally cylindrical shape). Ends  120   b  of cylinder  120  are installed into the apparatus according to a conventional arrangement to allow for axial rotation of the cylinder during the plating process. As shown schematically, each end  120   b  of cylinder  120  is mechanically coupled (e.g., using a chuck or like holding device) to an adapter  120   c  (also allowing for size differences in cylinders) which is retained within a bearing  120   d  for rotational movement about the axis of cylinder (e.g., imparted by a motor, not shown). Brushes  120   e  provide an electrical connection (i.e., as cathode) to cylinder  120 . 
     According to other exemplary embodiments, cylinder  120  includes a steel (e.g. 99 percent steel) base surface, as is conventional. Exemplary cylinders are commonly available (from commercial suppliers) in a variety of sizes, which can be plated according to the methods taught herein. Such cylinders after plating and engraving are used for printing packaging or publications (e.g., magazines); exemplary cylinder surface diameters and lengths (i.e., surface area to be plated, engraved and printed out) will suit particular applications. Following the plating of the cylinder, the surface can be polished, then engraved with an image, for example using engraving system  270  as shown schematically in  FIG. 4 , including a scanner  272 , computer-based controller  274  and an engraver  276 . Such systems are commercially available, for example, from Ohio Electronic Engravers, Inc. of Dayton, Ohio, U.S.A. (Model No. M820). The cylinder can be cleaned (and chrome-plated) and then printed out (according to processes known to those in the art who may review this disclosure), for example, onto a roll or web of paper using a printing system  280  (including cylinders  220 ) as shown schematically in  FIG. 3 . When use of the cylinder in the printing operation is completed, the image is removed from the surface of the cylinder (e.g., stripped off if engraved on a Ballard shell or cut off if engraved on a base copper layer). The cylinder can be cleaned and deoxidized, then replated (e.g., with base copper) and engraved for reuse. (Other materials may be similarly plated or engraved and printed on the cylinder by alternative embodiments, such as chrome or zinc.) 
     According to any exemplary embodiment, apparatus  110  includes an anode system  128  that can accommodate or adjust to accommodate cylinders having different diameters. In one such embodiment, shown in  FIG. 5 , anode system  128  is coupled to an adjustable rail  144  (shown disposed upon at least one lifter  174  (hydraulic cylinder)) that is raised or lowered depending on the size of cylinder  120  to be plated or deplated. When a cylinder of a lesser diameter is used, anode system  128  is raised so that anode system  128  is brought to an optimal distance (i.e., 5 mm to 80 mm, preferably 10 mm to 60 mm, or, according to an exemplary embodiment, 10 mm to 30 mm) from cylinder  120  as may be determined for a particular application. 
     According to an exemplary embodiment of a type shown schematically in  FIGS. 1 ,  9 , and  22 , apparatus  110  includes a plating tank  112  having side walls  112   a  and  112   b , and bottom  112   c  containing the plating solution (electrolytic fluid F) at a level (indicated by reference letter L) regulated by the height of a weir  172  (e.g., the top of side wall  112   b ), although a variety of methods for controlling the fluid level may be used (i.e., a pump, drain, sensor etc.). Plating tank  112  can take a variety of different shapes and sizes and may be manufactured from any one or a combination of suitable materials. In an exemplary embodiment, plating tank  112  is formed of a material that is substantially resilient to the plating solution (e.g., titanium, plastic, rubber, graphite, glass, silver, etc.), or, as shown in  FIG. 6 , includes a protective surface material  124  (e.g., lining, coating, sealing, covering, surface treatment, etc.) that is substantially resilient to the plating solution. 
     According to any preferred embodiment for plating a rotogravure cylinder, the tank system and cylinder mounting and drive system are of a conventional arrangement known to those of ordinary skill in the art of rotogravure cylinder plating. (Plating stations that may be adapted to incorporate various embodiments of the present invention are commercially available, for example, from R. Martin A G of Terwil, Switzerland.) The cylinder mounting system may be configured to support cylinder  120  in a horizontal position, as shown schematically in  FIG. 1 , or a vertical position as shown schematically in  FIG. 21 . 
     The plating solution is itself of a composition known to those of ordinary skill in the art of electroplating; for example, for copper plating, a solution of 120 to 295, preferably 270 to 290 gram/liter copper sulfate and 40 to 80, preferably 50 to 60 gram/liter sulfuric acid, to fill plating tank  112  to level L. The plating solution may be of a composition known to those who may review this disclosure. According to an exemplary embodiment for copper plating, the plating solution may be refreshed by adding sources of copper such as copper sulfate, copper oxides, cuprous oxide etc. (such as that described in U.S. Pat. No. 5,707,438 incorporated by reference herein), or the like (e.g. copper oxide provided to the solution through the oxidation of copper) to one or both of plating tank  112  and holding tank  114 . 
     According to some embodiments, the concentration of the plating solution is controlled by a volumetric feeder, sensor array (i.e., a Baumé sensor) in or near one or both of plating tank or holding tank. Sensor array  170  (shown schematically in  FIG. 9 ) may be of a type known to those who may review this disclosure. According to an exemplary embodiment, the concentration of the plating solution is controlled by pumping the solution through a clear tube with an optical device hooked up to a controller (e.g., a computing device); when the controller detects a low concentration (e.g., by more light passing through the solution than the threshold) it triggers a valve to deliver or introduce (possibly from a separate container) a refreshed solution or a material that will refresh the solution (i.e., nickel, zinc, copper sulfate, copper oxide, cuprous oxide, etc.) directly or indirectly into one or both of the plating tank and holding tank; refreshing the plating solution continues until the concentration rises sufficiently to trigger the controller to shut the valve. 
     According to any preferred embodiment, the plating solution includes a commercially available hardening agent or hardener (e.g., DisCop commercially available from Chema Technology, Inc., Milwaukee, Wis., U.S.A. (Part number CH-DisCop)). Other suitable hardening agents can be of a composition known to those who may review this disclosure. The amount of hardening agent added to the plating solution will depend on the specific hardening agent and the manufacturer&#39;s recommendations. For example, a suitable mixing ratio for DisCop is about 7 to 8 mL hardener per gallon of plating solution. More suitably, 7.4 to 7.6 mL hardener per gallon of plating solution. In some embodiments, the hardener may be selected to be substantially chloride-free or may be selected to comprise chloride. Brighteners may also be used, in the solution. 
     According to any preferred embodiment, anode system  128  includes a non-dissolvable anode  130  (i.e., an anode or cathode for deplating) made from a conductive material substantially resilient to the plating solution, or a conductive material including, at least partially, a surface material or treatment (or combination of surface materials and/or treatments that is substantially resilient to the plating solution) for plating or deplating an object with various metals or metallic alloys (i.e., nickel, zinc, copper, etc.) directly out of solution to produce a uniform and consistent grain structure on the surface of the object. 
     According to any preferred embodiment, anode system  128  is at least partially disposed into plating solution F below level L such that anode system  128  will remain in electrical contact with plating solution F during the plating process. In some embodiments, non-dissolvable anode  130  can be disposed into solution F below level L. 
     Anode system  128  may include a continuous anode (i.e., a conductive plate disposed near cylinder  120 ), a plurality of anodes coupled to or contacting one another, or a plurality of independent anodes separately coupled to a power supply. As shown schematically in  FIGS. 1 ,  9  and  22 , and  39  anode system  128 , is electrically coupled to at least one current carrying rail  144  (e.g., bus bar). In an exemplary embodiment, anode system  128  is mechanically coupled to a pair of rails  144 , which are shown extending along walls  112   a  and  112   b  of plating tank  112 . (Rails  144  are shown mounted from a reinforcing structure  141  in  FIG. 1 ; according to an alternative embodiment, the ends of the rails may be supported by the tank ends or side walls.) Alternatively, as shown in  FIG. 14 , anode system  128  may be electrically coupled and mechanically supported from beneath by rail  144  (which is in turn electrically coupled and mechanically supported by column  178 ) electrically coupled to anode system  128 . As shown in  FIGS. 1 and 9 , anode system  128  is mechanically fastened and electrically coupled to rail(s)  144  at junctions employing fasteners  145 , shown as bolts. 
     According to an exemplary embodiment, shown schematically in  FIG. 39 , anode system  128  does not encompass any substantial portion of the outer perimeter of cylinder  120 . This relationship may vary in alternative embodiments, such as those shown in  FIGS. 18 and 20  which employ an anode system of a larger size or greater surface area relative to cylinder  120 . According to an exemplary embodiment, shown schematically in  FIGS. 8 and 12 , anode system  128  is disposed around each side of cylinder  120  and follows the general shape or curve of cylinder  120 . As shown schematically in  FIGS. 6 ,  10 ,  14 ,  23 ,  24 ,  29 ,  30 ,  39 , and  41  anode system  128  may extend partially around cylinder  120 . Alternatively, as shown schematically in  FIG. 20 , anode system  128  may extend substantially or fully around cylinder  120 . 
     According to a particular embodiment, anode system  128  includes a heavier weight anode, an increased number of anodes, or a surface material such that the total anode weight or surface area (or cathode weight or surface area for deplating) is increased to provide for greater efficiency (and consistency) in the electroplating process by allowing usage of an increased current density (i.e. higher amperage and lower voltage). Typically, an increased current density reduces the plating time but increases the number or duration of additional polishing steps. However, utilizing an anode system having a non-dissolvable anode  130  with an increased current density not only reduces the plating time, but also minimizes the number or duration of additional polishing steps by reducing the amount of metallic sludge in the plating tank that may adhere to the cylinder and may cause uneven or undesirable deposits. 
     According to any preferred embodiment, anode system  128  includes at least one non-dissolvable anode  130  made from a conductive material substantially resilient to the plating solution (e.g., graphite, silver, titanium, platinum), or a conductive core  134  (e.g., lead, copper, titanium, etc.) covered, at least partially, by a protective a surface material  136  that is substantially resilient to the plating solution. While portions of anode system  128  may be coated with a nonconductive protective surface material  137 , at least portions of anode system  128  should include a conductive protective surface material  135  (e.g., graphite, titanium, platinum, silver conductive metal oxides or combinations thereof) that will maintain electrical contact between anode system  128  and plating solution F. The non-dissolvable anode may include a protective surface material or a combination of protective surface materials (e.g., a sleeve, wrap, surface treatment, powder coating, spray coating, brushing, dipping, sealing, powder coating, washing etc.) along its entire surface area, along a substantial portion of its surface area, or along only part of its surface area. According to other alternative embodiments, the surface material may include a material (e.g., a sheet, slat, strip, wrap, etc.) coupled to (e.g., adhered, welded, wrapped, shrunk, applied to or fastened by mechanical fasteners or otherwise, etc.) the core  134 . According to some embodiments, at least those portions of the anode system that may be exposed to corrosion or chemical attack by the plating solution (electrolytic fluid F) will be made from a material that is substantially resistant to the plating solution or include a protective surface material that is substantially resistant to the plating solution. 
     In an exemplary embodiment, core  134  is protected, at least partially, by a surface material  136  formed from (at least partially) a conductive surface material (e.g., graphite). Conductive surface material  135  may extend along the entire length of conductive core  134  or along a portion of conductive core  134 . In an exemplary embodiment, a plurality of conductive surface material pieces  186  are used to at least partially cover core  134 . As shown in  FIG. 13 , where a plurality of pieces  186  is used, pieces  186  may be adjoined using a angled abutment (depicted in  FIG. 13   a ), a stepped abutment (depicted in  FIG. 13   b ), a straight abutment (depicted in  FIG. 13   c ), or any other configuration that may be known to those who may read this description. According to any exemplary embodiment, non-dissolvable anode  130  may include conductive surface material  135  coupled to a portion of core  134  as shown in  FIG. 12 , or, as shown in  FIG. 15 , coupled to multiple surfaces of core  134 . In an alternate embodiment, portions of core  134  not covered by sheet material  186  may be covered, at least partially, by non-conductive material  137 . In an exemplary embodiment, to create a seal between conductive surface material  135  and non-conductive surface material  137 , non-conductive material  137  wraps around the edges of conductive surface material  135 , as shown in  FIG. 11 . Other methods may also be used to create a seal between conductive surface material  135 , non-conductive material  137 , or other materials constituting surface material  136 . 
     Alternatively, graphite is applied to protect core  134  using a spray or powder coating. According to a particularly preferred embodiment, protective surface material  136  includes coating or wash having a graphite content of more than 10 percent, and preferably a graphite content of more than 20 percent such as GRAPHOKOTE NO. 4 LADLE COATING (trade name with product data sheet Pds-G332 incorporated by reference herein), commercially available from Dixon Ticonderoga Company of Lakehurst, N.J., U.S.A. According to any preferred embodiment, the protective surface material (e.g., graphite) is securely applied to core  134 . 
     According to an alternative embodiment, shown in  FIG. 40 , anode system  128  includes a conductive core  134  and a layered protective surface material  136 . According to some embodiments, the protective surface material includes a valve metal base  262  and a conductive metal oxide coating  264 . According to some embodiments the conductive metal oxide coating can include at least one platinum-group metal or platinum-group metal oxide and at least one valve metal or valve metal oxide. Exemplary platinum-group metals and oxides thereof include, but are not limited to, ruthenium, ruthenium oxide, osmium, osmium oxide, rhodium, rhodium oxide, iridium, iridium oxide, palladium, palladium oxide, platinum and platinum oxide. Exemplary valve metals and oxides thereof include, but are not limited to, tantalum, tantalum oxide, titanium, titanium oxide, zirconium, and zirconium oxide. According to some embodiments, the protective surface material includes mixtures of metal oxides (e.g., iridium oxide and tantalum oxide). Exemplary conductive metal oxide coatings are described in U.S. Pat. No. 4,585,540 incorporated by reference herein, and U.S. Pat. No. 6,217,729 incorporated by reference herein. According to a particularly preferred embodiment, the conductive metal oxide coatings may include those commercially available from Eltech Systems Corporation of Fairport Harbor, Ohio, U.S.A. The conductive metal oxide coating can be applied to the valve metal base according to conventional procedures known to those who may read this disclosure. 
     According to any preferred embodiment, the valve metal base includes titanium. The titanium base may include the conductive core  134  or an intermediate titanium layer (e.g.,  260  or  262 ). As shown in  FIG. 40 , the conductive metal oxide coating  264  can be applied to the titanium base  262  which is applied to the conductive core  134  via a conductive intermediate layer  260  (e.g., platinum, titanium, etc.). According to an alternative embodiment, the titanium base  262  is applied directly to the conductive core  134 . According to some embodiments, the titanium base includes a titanium spray coating  262  securely applied to at least potions of the conductive core  134 . A spray coating may be selected to create a rough surface, which may increase the surface area of anode  130 . Some embodiments will increase the surface are of anode  130  by more than about 50 percent. A particularly preferred embodiment will increase the surface area of anode  130  by more than about 100 percent. 
     According to any exemplary embodiment, anode  130  may include multiple layers of surface materials. For example, anode  130  may include a conductive core  134  at least partially covered by a first layer (e.g., platinum, titanium, silver, graphite, etc.) and at least partially covered by a second layer (e.g., platinum, titanium, silver, graphite, conductive metal oxide, etc.). Some embodiments may include a first layer of titanium and a second layer of platinum. Some embodiments may include a first layer of titanium and a second layer of conductive metal oxide. According to an alternate embodiment, additional layers can be employed. 
     According to an alternate embodiment, shown in  FIGS. 18 and 19 , anode system  128  includes a non-dissolvable anode  130  that is entirely composed of a conductive material substantially resilient to the plating solution (e.g. graphite commercially available, for example, from Schunk Graphite Technology of Menomonee Falls, Wis.). As shown in  FIGS. 18 and 19 , anode system  128  includes a plurality of support members (e.g., a curved or angled supporting plate or at least one curved or angled flat supporting strip some of which may be made using a nonconductive material) mechanically fastened and electrically coupled to a plurality of non-dissolvable anodes  130 . In an exemplary embodiment, shown in  FIG. 19 , graphite non-dissolvable  130  are coupled to support members  142  using fasteners  145 , shown as screws. According to any embodiment, particularly those where graphite is used, preferably at least portions of the anode system are sealed (preferably high pressure sealing commercially available, for example, from Schunk Graphite Technology of Menomonee Falls, Wis.) or baked. According to some embodiments, support members  142  and non-dissolvable anodes  130  are connected using fasteners  145  (shown as screws) made of a material that is substantially resilient to the plating solution (e.g., graphite). 
     According to any preferred embodiment, the contact surfaces between anode system  128  and current carrying rails  144  are maintained free of any surface material that may materially diminish the electrical current flowing between non-dissolvable anode  130  and current carrying rails  144 . Likewise, according to some embodiments the contact surfaces of the anode system  128  are maintained free of any surface material that may materially diminish the electrical current (i.e., contact between support members  142  and non-dissolvable anode  130 ). According to an exemplary embodiment, contact surfaces include a conductive surface material (e.g., platinum, titanium, etc.) on at least one of the contact surfaces (i.e., contact surfaces between support members  142  and non-dissolvable anode  130 ). 
     An alternate embodiment of anode system  128 , shown in  FIGS. 23 and 24 , includes at least one non-dissolvable anode  130  and at least one support member  142  that serves as the structural support (i.e. a hanger) for non-dissolvable anode  130 . According to a preferred embodiment, support member  142  acts, at least partially, as non-dissolvable anode  130 . According to an exemplary embodiment, a plurality of non-dissolvable anodes  130 , which may be placed in a variety of configurations, are used. Support member  142  is mechanically fastened and electrically coupled to current carrying rails  144  at junctions employing fasteners  145 , shown as bolts. According to an alternative embodiment, shown in  FIG. 19 , only a portion of support members  142   a  are electrically coupled to current carrying rails  144 . A second portion of support rails  142   b  may be made from a nonconductive material (e.g., plastic) and implemented chiefly as a support mechanism for anode  130 . Portions of the support members  142  may include a surface material (conductive or nonconductive) to protect, or further protect the portions from the plating solution. 
     According to an exemplary embodiment, titanium tubes, which may include a protective surface material, are shrunk onto a lead or copper core material. As shown in  FIG. 25 , non-dissolvable anode  130  may take numerous forms, shapes, or proportions, including having a generally round cross-section (depicted in  FIG. 25   a ), a square cross-section (depicted in  FIG. 25   b ), a generally rectangular cross-section (depicted in  FIG. 25   c ), or of a wide variety of shapes, sizes, proportions, or combinations thereof. According to a preferred embodiment, the ends of core  134  are also protected by a protective surface material. According to one embodiment, shown in  FIGS. 25   a - c , surface material  136  includes caps  140  attached to side portions  139  of protective surface material  136 . Depending on the type or nature of the protective surface material used, other methods of protecting the ends of core  134  may be implemented. 
     According to an alternate embodiment, shown in  FIGS. 25   a - b , a hollow tube  146  manufactured from a conductive material that is resilient to the corrosive effects of the plating solution (e.g., graphite, titanium, etc.), or including a conductive protective surface material substantially resilient to the effects of the plating solution, is filled with a plurality of conductive elements or pieces  148 . An exemplary embodiment utilizes metallic elements (e.g., lead or copper alloy balls or nuggets) to fill tube  146 . Caps  140 , attached to tube  146 , seal the ends  147  of the tube and contain and protect the conductive elements  148 . Depending on the material used to manufacture tubes  146 , other methods of sealing the ends of tubes  146  may be implemented. Tubes  146  may take numerous forms or proportions, including a generally round cross-section as depicted in  FIG. 26   a , a generally rectangular cross-section as seen in  FIG. 26   b , or of a wide variety of shapes, proportions, or combinations thereof. According to an exemplary embodiment, the anode system includes a porous covering (e.g., a polypropylene mesh) covering at least portions of the anode system. The porous covering helps to prevent any particles separated from the anode system from freely entering the plating solution. An exemplary embodiment utilizes the porous covering to further protect the anode system as well as filter the plating solution. 
     As shown in  FIG. 24 , apparatus  110  may employ multiple layers of non-dissolvable anodes  130 , which may be placed in a variety of configurations, thereby further increasing the size (or surface area) of the anode. One row of non-dissolvable anodes  130  may be directly “stacked” on another, or, as shown in  FIG. 24 , be separated by partition  156 . According to some embodiments, partition  156  is made of electrically conductive mesh or expanded metal material (e.g., having apertures). Partition  156  may be attached to non-dissolvable anodes  130  or support members  142  by welding or other comparable method or fixture. As depicted in  FIGS. 23 and 24 , according to an exemplary embodiment, anode system  128  includes a covering  154 . Anode system  128  may also include non-dissolvable anodes  130 . Covering  154  may be configured to cover non-dissolvable anodes  134 . According to some embodiments, covering  154  is made of electrically conductive mesh or expanded metal material (e.g., having apertures). Covering  154  is attached to conductors  132  or support structure  144  by welding or other comparable fixture. According to any particular preferred embodiment, the apertures within the mesh (or expanded metal material) create flow paths for circulation of the plating solution, increase the surface area for the anode, and further promote uniform transmission of the ultrasonic energy. Covering  154  may comprise platinum or titanium. 
     According to any of the preferred embodiments, the ability to perform plating of a rotogravure cylinder  120  directly out of solution using a non-dissolvable anode  130  eliminates the need to place unprotected solid metallic material (i.e., copper nuggets or any other unprotected anode susceptible to corrosion or chemical attack) in close proximity to cylinder  120 . This configuration substantially reduces or eliminates uneven or undesirable deposits on a cylinder as result of the sludge caused by dissolution of an unprotected anode or other unprotected surfaces. The plating process according to any preferred embodiments is thereby intended to produce a more uniform, consistent grain structure of the plated material as well as to speed the plating by allowing more energy (i.e. a higher current density on the plated surface) to be applied during plating without adverse effects. 
     The plating process according to any preferred embodiment is intended to speed up the plating process yet produce a more uniform, consistent grain structure of the plated material on the cylinder and reduce the amount of polishing and other subsequent steps to prepare the cylinder for use. 
     According to other preferred embodiments, shown schematically in  FIGS. 1 ,  9 ,  22 , and  39  ultrasonic energy may be used in conjunction with the plating process using an anode system  128  having at least one non-dissolvable anode  130 , to provide a more uniform and consistent grain structure on the plated surface of cylinder  120 . 
     As shown schematically in  FIGS. 1 ,  9 ,  22 , and  39  a transducer element  150 , or plurality of transducer elements can be readily installed within plating tank  112  to introduce ultrasonic wave energy to facilitate the plating process. Multiple ultrasonic transducer elements can be installed in the plating tank (and may be disposed beneath non-dissolvable anode  132  as shown in  FIGS. 6 ,  10  and  14 ) to ensure coverage (i.e., transmission of ultrasonic wave energy to) along the entire length of the surface of cylinder  120 . The transducer elements  150  (shown as two elements) are electrically coupled to a control system and are provided to introduce ultrasonic wave energy into plating tank  112 . Transducer elements  150  can be of any type disclosed or of any other suitable type that may be known to those who review this disclosure, and can be mounted or inserted according to any suitable method. 
     Alternative embodiments may employ various arrangements of transducer elements to optimize plating (and deplating) performance in view of design and environmental factors (such as the ultrasonic energy intensity, flow conditions, sizes, shapes and attenuation of the tank, anode system, cylinder, etc.). According to a preferred embodiment, transducer elements  150  include a protective surface material. Transducer elements  150  are configured and positioned to assist with the plating process (e.g. to facilitate consistency of ion migration through the electrolytic fluid), and to prevent any fouling buildup on the various elements of apparatus  110 . 
     Referring to  FIGS. 1 ,  9 ,  22 , and  39  shown disposed lengthwise along the bottom surface of plating tank  112  (e.g., bonded or securely mounted thereto) are ultrasonic transducer elements  150 . Transducer elements  150  can be of any variety known in the art. In the exemplary embodiment shown in  FIG. 1 , a portion of the transducer elements are configured and positioned in relation to anode system  128  as to assist with the plating process directly (e.g., to facilitate consistency of ion migration to cylinder  120 ), and to provide a cleaning function and maintain anode system  128 , cylinder  120  and other elements of and about plating tank  112  free of sludge and other fouling buildup. 
     Referring to  FIG. 32 , according to a preferred embodiment, the ultrasonic system includes an ultrasonic power generator  153  for transforming a commercial supply of electric power (e.g., typically provided at low frequency such as 60 Hz) to an ultrasonic frequency range (approximately 120 kHz), a transducer element  150  for converting the high frequency electrical energy provided by generator  153  into ultrasonic energy (i.e. acoustical energy) to be transmitted into and through the electrolytic fluid, and a low voltage direct current (DC) power supply  152  for powering generator  153  and transducer elements  150 . Alternative embodiments, however, may operate at higher frequencies (e.g. above 120 kHz), where cavitation action tends to result, or may operate over a varying range of frequencies. According to a particularly preferred embodiment, the transducer elements are designed to provide for operation in a frequency range of 15 to 30 kHz (cycles). 
     As has been described, the plating process is enhanced by the introduction of ultrasonic wave energy into the plating tank. An ultrasonic generator converts a supply of alternating current (AC) power (e.g. at 50 to 60 Hz) into a frequency corresponding to the frequency of the ultrasonic transducer system (oscillator); the usual frequency is between 15 or 120 kHz and 40 kHz. The energy to the transducer (from the generator or oscillator) is supplied by means of a protected connection (e.g. a cable) transmitting energy at the appropriate frequency. The transducer element converts the electrical energy into ultrasonic energy, which is introduced into the plating solution as vibration (at ultrasonic frequency). The vibration causes (within the plating solution) an effect called cavitation, producing bubbles in the solution which collapse upon contact with surfaces (such as the plated cylinder). The greater amount of ultrasonic wave energy introduced into the plating tank, the greater this effect. 
     According to an exemplary embodiment, two, three, or more ultrasonic transducer elements can be installed in a staggered or offset pattern to ensure coverage of (i.e. transmission of ultrasonic wave energy to) and along the entire length of the surface of the cylinder, as shown in  FIGS. 33 and 34 . 
     According to any preferred embodiment, the transducer element is provided with some type of protective outer cover, preferably electrically isolated and resistant to the chemical and other effects of the plating solution. For example, the transducer element, may have a multi-layer protective cover with an outer layer and an inner covering sleeve (or like material) that forms a tight fit to the transducer element, made of “heat shrink” tubing, of a material (such as plastic or a like “inert” material) that is resistant to the effects of the plating solution. According to other alternative embodiments, the protective cover may include a layer of protective coating material (e.g., a coating) that can be applied directly to the transducer element by spraying, brushing, dipping, etc. (in place of or along with other “layers” or elements of protective cover). According to any alternative embodiment, the protective cover for the transducer element may be provided in a wide variety of forms and can include one or more layers of material or one or more elements (e.g. coating, wrap, sleeve, tube, fluid filled tube, etc.) that provides the protective function. 
     According to any preferred embodiment, the transducer elements efficiently convert electrical input energy from the generator into a mechanical (acoustical) output energy at the same (ultrasonic) frequency. The power generator is located apart from the plating tank, and may be shielded from the effects of the plating solution. The transducer elements can be generally of a ceramic or metallic material (or any other suitable material), and may have a construction designed to withstand the effects of the plating solution in which they are immersed, and positioned to provide uniform energy (and thus uniform cavitation) throughout the anode system and rotogravure cylinder. (Exemplary transducer elements are described in the articles cited herein previously and incorporated by reference herein.) Alternative embodiments may employ various arrangements of transducer elements to optimize plating (and deplating) performance in view of design and environmental factors (such as the ultrasonic energy intensity, flow conditions, sizes, shapes and attenuation of the tank, anode system, cylinder, etc.). 
     The use of ultrasonic energy increases plating rates by facilitating rapid replenishing of metal ions in the cathode film during electroplating. The ultrasonic energy is also very beneficial in removing absorbed gases (such as hydrogen) and soil from the electrolytic fluid and the surfaces of other elements during the electroplating process. According to any particularly preferred embodiment, the transducer elements are arranged to provide ultrasonic energy at an intensity (e.g. frequency and amplitude) that provides for uniform and consistent agitation throughout the plating solution suitable for the particular arrangement of plating tank  112 , cylinder  120  and anode system  128 . As contrasted to mechanical agitation, which may tend to leave “dead spots” in the plating tank with where there is little if any agitation, ultrasonic agitation may readily be transmitted in a uniform manner (according to the orientation of the array of transducer elements). 
     Ultrasonic agitation according to a exemplary embodiment will further provide the advantage of preventing gas streaking and burning at high current density areas on the cylinder without causing uneven or rough deposits. As a result, the use of ultrasonic energy to introduce agitation into the plating tank produces a more uniform appearance and permits higher current density to be used without “burning” the highest current density areas of the cylinder like the edge of the cylinder. (Usually the critical area of burning or higher plating buildup is the edge of the cylinder.) (Ultrasonic energy also can be used in chrome tanks to increase the hardness of the chrome, to increase the grain structure of the chrome and to eliminate the microcracks in chrome.) 
     A further advantage of a preferred embodiment of the plating apparatus using ultrasonic energy is that it expands the range of parameters for the plating process such as current density, temperature, solution composition and general cleanliness. The surface of a plated cylinder that used ultrasonic energy according to a preferred embodiment will tend to have a much finer grain size and more uniform surface than a cylinder that used a conventional plating process. The plated surface hardness would typically increase (without any additive) by approximately 40 to 60 Vickers, evidencing a much finer grain structure. The use of ultrasonic energy in the plating process therefore allows a minimum or no polishing of the cylinder. 
     According to a particularly preferred embodiment, the apparatus may employ a modular ultrasonic generator (e.g. Model No. MW GTI/GPI from Martin Walter) with at least one cylindrical “push-pull” transducer element (e.g. suitably positioned within the tank for efficient operation in the particular application); according to alternative embodiments, the transducer elements can be any of a variety of other types, installed on other tank surfaces and/or other orientations; the generator may be of any suitable type. 
     According to an exemplary embodiment, underneath transducer element  150  is placed a reflector  158  having a highly polished reflective surface shown mounted to side walls of plating tank  112 . Reflector  158  is shown in the preferred embodiment as being of an integral unit having an arcuate shape, and extends substantially along the entire length of cylinder  120  (as does transducer element  150 ). Alternatively, the reflector can be provided with any other suitable shape (such as parabolic or flat or multi-faceted) or in segments. Transducer element  150  when energized will transmit wave energy (shown partially by reference letter U in  FIG. 36 ) in a substantially radial pattern through the plating solution, including toward cylinder  120  and against reflector  158  which will reflect the wave energy back to cylinder  120  and related structures (such as the anode system  128 ). The direct and reflected ultrasonic wave energy is intended to keep the surfaces of the cylinder and related structures free of fouling buildup and to facilitate the plating process. 
     According to the preferred embodiments, plating can be conducted in accordance with the same basic range of values of process parameters as for plating by convention methods (i.e., without using a non-dissolvable anode or ultrasonic energy). The plating process according to the preferred embodiments is intended to produce a more uniform, consistent grain structure of the plated material as well as to speed the plating by allowing more energy (i.e., a higher current density on the plated surface) to be applied during plating without adverse effects. According to exemplary embodiments, copper can be plated with a current density in a range of approximately 1 to 3 amperes per square inch (as compared with 0.8 to 1.2 amperes per square inch as an example for a typical conventional process); chrome can be plated with a current density in a range of approximately 5 to 12 amperes per square inch (as compared with 5 to 7 amperes per square inch as an example for a typical conventional process). As a result, in an exemplary embodiment, plating may be accomplished as much as 40 to 50 percent faster, or an increased thickness of plated material can be achieved in a given time period. For example, all other parameters being maintained constant, if a conventional system plates a Ballard shell of approximately 0.0027 inches onto the cylinder in approximately 30 minutes without using ultrasonic energy, by using ultrasonic energy according to a preferred embodiment, after 30 minutes a Ballard shell of approximately 0.004 inches in thickness would be plated onto the cylinder. 
     According to an exemplary embodiment for plating with copper (e.g., from copper nuggets, cuprous oxide, cupric oxide, copper sulfate), the plating solution is maintained at a temperature of approximately 25 to 35° C. (preferably 30 to 32° C.) with a concentration of 180 to 295 grams/liter of copper sulfate (preferably 220 to 290 grams/liter) and 40 to 80 grams/liter of sulfuric acid (preferably 50 to 60 grams/liter); ultrasonic energy (i.e. power) can be applied in a range of 1.5 to 6 kVA. According to a particularly preferred embodiment for plating with chrome (e.g., directly out of solution), the plating solution is maintained at a temperature of approximately 55 to 65° C. with an initial concentration of 120 to 250 grams/liter of chromic acid and 1.2 to 2.5 grams/liter of sulfuric acid; ultrasonic energy (i.e., power) can be applied in a range of 1.5 to 6.0 kVA. As is apparent to those of skill in the art who review this disclosure, the values of process parameters may be adjusted as necessary to provide a plated surface having desired characteristics. According to alternative embodiments, these ranges may be expanded further, using the advantages of ultrasonic energy. 
     In comparison to conventional methods (e.g., without using ultrasonic energy), the rotogravure cylinder plated according to many embodiments will provide a surface better suited for subsequent engraving and printing. The plated surface of the cylinder will be characterized by a hardness similar to that obtained by conventional methods, but the grain structure (i.e., size) will be more consistent across and along the surface (i.e., both around the circumference and along the axial length of the cylinder), by example (for copper plating) varying approximately 1 to 2 percent (with ultrasonic) in comparison to approximately 4 to 10 percent (without ultrasonic). (According to other exemplary embodiments, the plated surface hardness may increase 120 to 30 Vickers.) 
     The surface plated according to one embodiment of the present invention will exhibit an engraved cell structure  200  as shown in  FIG. 38  (schematic diagram) with cell walls  202  of a generally consistent width and shape and relatively and substantially free of “burrs” or other undesirable deposits of material following the engraving process. By conventional methods, shown in  FIG. 37 , the structure of cell  201  is somewhat less consistent in form and dimension, as well as having material deposits  205  on or near walls  203  that may cause irregularities or defects during printing, see “The Impact of Electromechanical Engraving Specifications on Streaking and Hazing,”  Gravure  (Winter 1994), Which is incorporated by reference herein. Cells  200  of a consistent structure, as shown in  FIG. 38 , with less distortion and less damage during engraving, provide a surface on the cylinder which can more efficiently be inked and cleaned and which is therefore more capable of printing a high quality image in the final product. When, such uniformity and consistency can be achieved across the length of the cylinder (not just in isolated portions of the surface), the overall printing quality is enhanced. 
     According to any exemplary embodiment, as shown schematically in  FIGS. 1 , and  39  plating apparatus  110  includes holding tank  114  which may include at least one supply pipe  160 , and at least one spray bar  162  that supplies a flow of plating solution to plating tank  112 . The spray bar  162  can be adjustable to accommodate objects (e.g., rotogravure cylinders) of varying sizes. In a particularly preferred embodiment, an adjustable spray bar  162  is coupled to an adjustable anode system  128 . Supply pipes  160  are coupled to a circulation pump  164  (configured and operated according to a known arrangement) that may or may not have a filter system  166 . According to an exemplary embodiment, filter system  166  (including a system of multiple filters) is used to further reduce or minimize the amount of sludge in the plating solution or in plating tank  112  that may otherwise come into contact or near contact with cylinder  120 . As shown schematically in  FIG. 1 , circulation pump  164  draw plating solution F from holding tank  114  into inlets  161  in each of supply pipes  160  and force it under pressure through filter system  166  and into spray bars  162  where it is reintroduced through apertures into plating tank  112  for the electroplating process. In a preferred embodiment, each of spray bars  162  extends along the bottom of plating tank  112 , rising horizontally from holding tank  114  and turning to run horizontally along and beneath anode system  128 . According to alternative embodiments, apparatus  110  may include one pump and filter coupled to either a single spray bar or a spray bar manifold system, or any other combination of elements that provide for the suitable supply of plating solution F into plating tank  112 . According to an exemplary embodiment, filter system may include a porous material (e.g., polypropylene mesh) for filtering the plating solution. According to an exemplary embodiment, the holding tank and/or the plating tank is lined with a porous material which filters the plating solution or its precursors (i.e., any material used to create or refresh to the plating solution) before the plating solution is allowed to contact the cylinder. 
     Plating solution may build up heat and increase in temperature over time during the plating (or deplating) process and therefore plating tank  112  and/or holding tank  114  may be equipped with a fluid cooling system  116  (e.g., a suitable heat exchanger for such fluid of a type known in the art). Likewise, electrolytic fluid may need to be heated from an ambient temperature to a higher temperature at the outset of the plating process and therefore plating tank  112  and/or holding tank  114  may be equipped with a fluid heating system  118  (e.g., a suitable heat exchanger for such fluid of a type known in the art). The temperature regulating system for the plating solution can be coupled to an automatic control system that operates from information obtained by temperature sensors in or near one or both tanks, and to control other parameters that may be monitored during the process, according to known arrangements. Before the electroplating process begins, the ultrasonic system can be energized to provide for agitation of the electrolytic fluid and for cleaning the system to provide for better contact and plating performance. 
     According to any preferred embodiment, holding tank  114 , supply pipe  160 , spray bar  162 , filter system  166 , circulation pump  164 , mixing system  254 , heating system  118 , cooling system  116 , transducer element  150 , or other pieces that may be exposed to the plating solution (electrolytic fluid F) may be formed from a material substantially resilient to the plating solution, or include a surface material substantially resilient to the plating solution along their (individually or collectively) entire surface area, along substantial portions of their (individually or collectively) surface area, along part of their (individually or collectively) surface area, or strategically placed along those surfaces that may be exposed to corrosion or chemical attack. 
     In an exemplary embodiment, shown schematically in  FIGS. 9 ,  22 , and  39  a mixing or dosing tank  180  is coupled to holding tank  114 . Alternatively, dosing tank  180  may be coupled to plating tank  112 . Dosing tank  180 , in conjunction with one or more of a sensor array  170 , dosing pump  182 , timer (not shown), volumetric feeder (e.g., commercially available, for example from TecWeigh of St. Paul, Minn.) (not shown) or other like device, introduces a material that will refresh the plating solution (i.e., in the case of copper plating; copper sulfate, copper oxide, cuprous oxide, etc.) directly or indirectly into plating tank  112 . As shown schematically in  FIG. 9 , dosing tank  180  introduces (e.g., gravity feed, gear system, value system, etc.) a material that will refresh the plating solution into holding tank  114 , which then transfers the refreshed solution to plating tank  112 . Dosing tank  180  may include a diffuser to allow better mixing of the material used to refresh the plating solution into the plating solution and/or to ensure more complete ionization of the material. 
     According to an exemplary embodiment, dosing tank, holding tank, or plating tank can be lined with or otherwise includes a porous material (e.g., polypropylene mesh) for filtering the plating solution or its precursors (e.g., cupric oxide, cuprous oxide, copper sulfate) before the plating solution comes in contact with cylinder  120 . 
     According to an exemplary embodiment as shown schematically in  FIG. 39 , holding tank  114  or plating tank  112  can include a mixing system  252  to facilitate the dissolution and/or circulation of the copper plating material (e.g., cuprous oxide, cupric oxide, copper sulfate, etc.) into the plating solution. According to one embodiment, mixing system  252  can include a motor driven mixer (e.g., propeller, mixing blade or other mechanical agitation device). 
     According to any exemplary embodiment, a separate tank  252  can be used to introduce the hardening agent into the plating solution. The hardening agent can be introduced directly or indirectly into either the plating tank  112  or holding tank  114 . Tank  252 , in conjunction with a sensor array, dosing pump, timer, volumetric feeder or other like device, introduces the hardening agent directly or indirectly into the plating solution. 
     According to any exemplary embodiment, dosing tank  180 , tank  252 , sensor array, dosing pump, volumetric feeder, mixing system  254  or other constituent parts that may be exposed to the plating solution or its precursors may be formed from a material substantially resilient to the plating solution or its precursors along their (individually or collectively) surface area or along part of their (individually or collectively) surface area, or strategically placed along those surfaces that may be exposed to corrosion or chemical attack. 
     As shown in  FIG. 43 , the proximity of cylinder  120  to anode system  128  may be determined by a proximity sensor  129  (shown schematically). As shown in  FIG. 5 , lifter  174  may be controlled based on a signal output by proximity sensor  129 . 
     Other solution concentration parameters (e.g. hardener concentration, brightener concentration, etc.) may be monitored by one or more control systems using one or more additional sensors. 
     In exemplary embodiments, an anode may comprise a mesh or grid formed from a material substantially resilient to the plating solution. 
     According to exemplary embodiments, non-dissolvable anodes may be in direct contact with one another. In alternate embodiments the non-dissolvable anodes are spaced apart. The anodes may contain spaces between portions of the conducting materials that allow the plating solution to flow through the spaces between the anodes. These embodiments may comprise solid anodes spaced apart and may include meshes or grids. 
     Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments (such as variations in sizes, structures, shapes and proportions of the various elements, values of the process parameters, mounting arrangements, or use of materials) without materially departing from the novel teachings and advantages of this invention. Other sequences of method steps may be employed. Accordingly, all such modifications are intended to be included within the scope of the invention as defined in the following claims. In the claims, each means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the preferred embodiments without departing from the spirit of the invention as expressed in the appended claims. It should be understood that the plating apparatus according to alternate embodiments may be configured to plate alternate types of objects.