TRANSPORT ROLLER AND CORRESPONDING MANUFACTURING PROCESS

Description

[0001] The invention relates to a device for printing a recording medium, comprising a transport roller. The transport roller has a base body on whose outer surface a protective layer is formed. The invention further relates to a device for turning over a recording medium and a method for producing a protective layer on a portion of the surface of the base body of the transport roller.

[0002] From the unpublished patent application DE 10 2020 120 412.4, a heating element is known that is part of a drying or fixing unit. The fixing unit is designed like a printing station to dry the ink of the printed image and fix it to the paper.

[0003] Document US 4,146,659 A discloses a heating roller for a fuser unit of an electrophotographic printer, which has a coating that may include ruthenium. This roller serves as a fuser roller to press the toner onto the paper.

[0004] Ruthenium coatings are therefore only known in the prior art for heated elements.

[0005] Furthermore, coatings of rollers or other guide elements made of silicone or Teflon are known to be used in printing or copying.

[0006] In conventional inkjet printing systems, the recording medium is first printed on one side using a first printing unit. The ink applied to the recording medium to create the image is then dried by a drying unit. The recording medium is then turned over by a flipping station, so that the reverse side of the recording medium, fed to a second printing unit, is printed with a second image. Finally, the recording medium is fed to a second drying unit, which dries the ink from the image printed on the reverse side.

[0007] The turning station flips the recording medium so that the unprinted reverse side faces the second printing unit. This allows for the use of two identical printing units, enabling a cost-effective configuration of the printing system. During the turning of the recording medium, the front side, printed with the first image, comes into contact with rollers of the turning station and / or rollers of the subsequent printing unit, particularly in a looper located between the printing units. In such a looper, the recording medium is pressed against the rollers with a relatively high force, which can lead to smearing of the ink from the first image and / or ink adhering to the roller surface.

[0008] The object of the invention is to provide a device for printing on a recording medium, which prevents contamination of the surface of a roller used to guide the recording medium after printing with the inkjet printer unit and drying of the printed image, and ensures that the printed image is not impaired. Furthermore, a turning unit and a method for producing a protective coating on the base body of a transport roller are to be provided.

[0009] This problem is solved by a device having the features of claim 1. Furthermore, the problem is solved by a device for turning over a recording medium having the features of claim 4 and by the methods having the features of the independent method claims. Advantageous embodiments are specified in the dependent claims.

[0010] By applying a protective coating to the outer surface of the roller's base body, comprising at least a ruthenium layer, similarly favorable triboelectric properties are achieved as with a hard chrome layer; that is, there is only minimal friction between the protective coating and the recording medium. Furthermore, the ruthenium layer is significantly less susceptible to adhering ink particles than the hard chrome layer. The protective coating also ensures that the printed image on the recording medium, once dry, is not affected, and in particular, is not smudged, even if the ink has not yet completely dried.

[0011] The recording medium is preferably a web-shaped recording medium, also known as an endless recording medium. The transport roller can be driven or free-running. The base body, on whose outer surface the protective coating is formed, can be made of aluminum, copper, iron, steel, stainless steel, aluminum alloys, copper alloys, iron alloys, and / or steel alloys.

[0012] Since ink particles adhering to the surface of a transport roller degrade the quality of subsequent printed images, the device according to claim 1 also leads to improved print quality. The transport roller with the protective layer formed according to the invention is arranged downstream of a first printing unit and a first drying unit, as the printed image of the recording medium only comes into contact with the surface of the transport roller there. In particular, the transport roller is part of a turning unit for turning the recording medium and / or part of a subsequent second printing unit.

[0013] A second aspect of the invention relates to a device for turning over a recording medium with at least one transport roller according to the invention.

[0014] A third and a fourth aspect each concern a method for producing a protective layer on the outer surface of a transport roller for transporting a recording medium, in particular a recording medium already printed with an image. The described methods each create a protective coating on the outer surface of the transport roller's base body, comprising at least a ruthenium layer. This achieves similarly favorable tribological properties as a hard chrome layer, i.e., only minimal friction occurs between the protective coating and the recording medium. Additionally, the ruthenium layer is significantly less susceptible to adhering ink particles. The permanent adhesion of ink particles to the protective coating is considerably reduced with a ruthenium coating compared to other known protective coatings.

[0015] Further features and advantages of the invention will become apparent from the claims and the following description of preferred embodiments, which are described with reference to the accompanying drawings.

[0016] They show: Figure 1 is a schematic representation of an inkjet printing device according to a first embodiment, Figure 2 is a detailed representation of a flip unit of the printing device according to Figure 1 Figure 3 is a schematic representation of an inkjet printing device according to a second embodiment, Figure 4 is a schematic representation of a transport roller with a protective layer, Figure 5 shows the structure of the protective layer on a lateral surface of the transport roller according to Figure 4 , and Figure 6 shows a flowchart for creating the protective layer according to Figure 5 .

[0017] Figure 1Figure 1 shows a schematic representation of an inkjet printing device 100 according to a first embodiment, which is designed for printing on a tape-shaped recording medium 120. The recording medium 120 can be made of paper, cardboard, carton, metal, plastic, textiles, a combination thereof, and / or other suitable and printable materials. The recording medium 120 is transported through the inkjet printing device 100 along the transport direction P1, which is indicated by an arrow. In other embodiments, the inkjet printing device is designed for printing on sheet-shaped, flat, or disc-shaped recording mediums 120.

[0018] The inkjet printing device 100 comprises a first inkjet printer 110 for printing the front side of the recording medium 120 and a second inkjet printer 112 for printing the back side of the recording medium 120. A turning unit 114 for turning the recording medium 120 is arranged between the inkjet printers 110 and 112. The recording medium 120 is fed to the first inkjet printer 110 with the front side facing up. After the first inkjet printer 110 has printed an image on the front side, the recording medium 120 is turned over in the turning unit 114 so that the recording medium 120 is fed to the second inkjet printer with the back side facing up. The second inkjet printer 112 then prints an image on the back side of the recording medium. The 110 and 112 inkjet printers can each produce a monochrome or multicolor print image on the front or back panel.Print on the reverse side of the recording medium 120. One such in . Figure 1 The arrangement shown, consisting of two identical inkjet printers 110, 112 and a flip unit 114 arranged between the inkjet printers 110, 112, is also referred to as the TWIN system.

[0019] The inkjet printers 110 and 112 of the printing device 100 can each comprise a printing unit with at least two print bars, each print bar being usable for printing with ink of a specific color, e.g., black, cyan, magenta, and / or yellow, and optionally MICR ink. Different print bars can be used for printing with different inks. Furthermore, the inkjet printers 110 and 112 each comprise at least one drying unit configured and designed to dry a printed image printed onto the recording medium 120 by means of the respective printing unit.

[0020] A print bar can comprise one or more printheads arranged side by side in several rows to print the pixels of different columns of a print image onto the recording medium 120. In a specific embodiment, a print bar comprises five printheads, each printhead printing the pixels of a group of columns of a print image onto the recording medium 120. A print bar can, in particular, comprise a number of printheads in the range of 5 to 20, and especially in the range of 5 to 9.

[0021] Each printhead of the printing unit comprises multiple nozzles, each nozzle configured to fire ink droplets onto the recording medium 120 or to eject them in the direction of the recording medium 120. For example, a printhead of the printing unit may comprise several thousand effectively used nozzles arranged along multiple rows transverse to the transport direction P1 of the recording medium 120.

[0022] The printing device 100 further comprises at least one control unit, e.g. a control hardware and / or a controller, which are configured to control the actuators of the individual nozzles of the individual printheads of the printing units in order to print the print image on the front or on the back of the recording medium 120 depending on print data.

[0023] The drying unit of each inkjet printer 110, 112 is configured to dry the recording medium 120 after the ink has been applied by the one or more printing plates. The drying unit can be controlled by the control unit of the printing device 100. For example, the drying can be carried out depending on the amount of ink applied and / or depending on the type of recording medium 120, in particular depending on the absorption properties of the recording medium 120 used.

[0024] Figure 2shows a detailed representation of the turning unit 114 after Figure 1 The recording medium 120 is printed by the inkjet printer 110 with the front side facing up and fed to the flipping unit 114 at its input 116 with the printed side facing up. At the output 118 of the flipping unit 114, the recording medium 120 is flipped, i.e., printed with the back side facing up. The recording medium 120 is then fed to the input of the second inkjet printer 112.

[0025] The flipping unit 114 has, viewed in the transport direction P1 of the recording medium 120, a first inclined transport roller 122, which deflects the recording medium 120 by 90°. This is followed by a second transport roller 124, which also serves as a deflection element and deflects the recording medium 120 by 180°. From there, the recording medium 120 passes to a second inclined transport roller 126, which deflects the recording medium 120 by 90°. At the output 118 of the flipping unit 114, the flipped recording medium 120, i.e., with the reverse side facing up, is then ejected. The recording medium 120, with the reverse side facing up, can then be fed to the second inkjet printer 112. The second inkjet printer 112 then prints an image onto the back of the recording medium 120. The surfaces of the transport rollers 126 and 124 contact the printed front of the recording medium 120.To prevent ink deposits on the surface of the transport rollers 124, 126 and to prevent impairment of the printed image on the front side by ink transfer from the recording medium 120 to the surface of the transport rollers 124, 126 and / or blurring of the printed image on the front side of the recording medium 120, the transport rollers have a protective layer 125, 127.

[0026] Figure 3Figure 1 shows a schematic representation of an inkjet printing device 200 according to a second embodiment. The inkjet printing device 200 is a duplex printer for printing on the front and back of a web-shaped recording medium 120. In contrast to the printing device 100, the printing device 200 has a first printing module 210 for printing a print image on the front of the recording medium 120 and a second printing module 212 for printing a print image on the back of the recording medium 120. Elements with the same structure and / or function have the same reference numerals.

[0027] The web-shaped recording medium 120 is transported along a paper path in the transport direction of arrows P1 through the printing device 200. A turning unit 214 is arranged in the transport direction P1 of the recording medium 120 after the first printing module 210 and before the second printing module 212.

[0028] The print modules 210, 212 each have a print unit 216, 220 and a drying unit 218, 222 for drying the printed image printed onto the recording medium 120 by means of the respective print unit 216, 220. The design and function of the print units 216, 220 and the drying units 218, 222 correspond to the print units and drying units of the printers 110, 112 of the first embodiment. In the second embodiment, at least one control unit for controlling the print modules 210, 212 and the flip unit 214, as well as any additional units, is provided in the same manner as in the first embodiment.

[0029] For the transport and guidance of the recording medium 120, the first printing module 210 has at least two transport rollers 224, 226 and the second printing module 212 also has two transport rollers 228, 230.

[0030] The first print module 210 feeds the recording medium 120, with its printed front side facing up, to the flipping unit 214. In the flipping unit 214, the recording medium 120 is then flipped and output to the second print module 212 with the front side down and the back side up, where a second print image is printed onto the back of the recording medium 120.

[0031] The turning unit 214 comprises 5 transport rollers 232 to 240. Transport rollers 232, 234 and 236 contact the back of the recording medium 120. Transport rollers 236 and 238 contact the front of the recording medium 120, which has been printed by the printing unit 216 of the first printing module 210. Furthermore, transport rollers 228 and 230 of the second printing unit 212 contact the front of the recording medium 120, which has already been printed by the printing unit 216 of the first printing module 210.To prevent ink deposits on the surface of the transport rollers 228, 230, 232, 234, and 236, and to prevent impairment of the printed image on the front side by ink transfer from the recording medium 120 to the surface of the transport rollers 228, 230, 232, 234, and 236 and / or blurring of the printed image on the front side of the recording medium 120, the transport rollers 228, 230, 232, 234, and 236 have a protective coating.

[0032] Figure 4Figure 1 shows a schematic representation of a transport roller 300 with a base body 310 and a protective layer 312. The transport roller 300 can be used, in particular, as a transport roller 228, 230, 232, 234, and 236 in printing devices 100 and 200. The transport roller 300 can directly contact a printed image printed onto a recording medium 120 by means of an inkjet printing unit and dried by means of a drying unit through the protective layer 312, without any impairment of the printed image by ink transfer from the recording medium 120 to the protective layer 312 of the transport roller 300 and / or smearing of the printed image on the front of the recording medium 120. The protective layer 312 comprises at least one ruthenium layer.

[0033] Figure 5 shows, by way of example, the structure of the protective layer 312 of a surface, i.e. on the outer surface, of the transport roller 300. Figure 4The base body 310 is made of aluminum in the present embodiment.

[0034] In other embodiments, the base body 310 can also be made of an aluminum alloy, copper, a copper alloy, iron, steel, stainless steel, an iron alloy, and / or a steel alloy, or at least comprise at least one of these materials. The base body 310 is rotatably mounted in a suitable manner and can optionally be driven by means of a drive unit. The base body 310 has a circular outer diameter and can be made of solid material or be tubular, at least in a partial section.

[0035] In the present embodiment, a zincate pickling layer 166 is produced on the outer surface of the aluminum base body 310 by means of chemical deposition. Prior to this, the surface onto which the zincate pickling layer 166 is applied can be pretreated in a suitable manner, in particular by blasting with a suitable abrasive. A suitable abrasive is, for example, aluminum oxide with a grain size of 200 µm to 240 µm. For example, aluminum oxide with a grain size of 220 µm can be used. Other suitable cleaning and / or pretreatment processes can be carried out additionally or alternatively.

[0036] After the application of the zincate pickling layer 166, a nickel sulfamate layer 168 is produced by chemical and / or electroplating. Subsequently, a phosphate-containing nickel layer 170 is applied to the nickel layer 168 by chemical deposition. A palladium layer 172 is applied to the phosphate-containing nickel layer 170 by chemical deposition, and the ruthenium layer 174 is applied to the palladium layer 172 by chemical deposition. The ruthenium layer 174 forms the surface 176 of the transport roller, which is contacted by the printed side of the recording medium 120. The layer structure consisting of the zincate pickling layer 166, the nickel layer 168, the phosphate-containing nickel layer 170, the palladium layer 172, and the ruthenium layer 174 proposes a five-layer system that has at least as good tribological properties as a hard chrome layer.The tribological properties relate in particular to the friction occurring between the recording carrier 120 and the transport roller 310, as well as the wear behavior of the protective layer 312 and the corrosion or susceptibility to corrosion of the protective layer 312.

[0037] Chemical deposition is achieved by immersing the substrate 310 in a chemical bath. Therefore, this process is referred to as chemical bath deposition. The deposition of thin layers of a desired substance onto the substrate 310 occurs through ion reactions and the aggregation of colloidal particles. Chemical bath deposition is particularly cost-effective, as it does not require expensive equipment.

[0038] Alternatively or additionally, individual layers 166 to 174 can be produced by galvanic processes or by electrolysis. In galvanic processes, the base body 310 serves primarily as the cathode, onto which the desired material is deposited from an electrolytic bath. Typically, the metal to be deposited is located at the positive terminal, or anode, and the object to be coated is located at the negative terminal, i.e., the cathode. In galvanic processes, metallic deposits are electrochemically depositiond, allowing coatings or layers to be applied to the base body 310. For this purpose, the base body 310 to be coated is immersed in an electrolytic bath.In the present embodiment, the zincate pickling layer 166 has a layer thickness of 200 nm, the nickel layer 168 has a layer thickness of 3 µm, the phosphate-containing nickel layer 170 has a layer thickness of 15 µm, the palladium layer 172 has a layer thickness of 0.5 µm and the ruthenium layer 174 has a layer thickness of 1.5 µm.

[0039] Compared to the hard chrome plating of the transport roller 310, the ruthenium layer 174 or the proposed layer structure of the protective layer 312 has the advantage that no chromic acid is required for the production of the protective layer 312, thus protecting the environment and in particular avoiding the high disposal costs for chromic acid.

[0040] The zincate pickling layer 166 is produced, in particular, by chemical deposition in a zincate pickling bath, wherein the bath temperature preferably has a value in the range of 10°C to 25°C and / or the treatment time in the bath preferably has a value in the range of 60 s to 120 s. To produce the nickel layer 168 by the base body 310, chemical deposition is carried out in a nickel sulfamate bath, wherein the bath temperature of the nickel sulfamate bath preferably has a value in the range of 30°C to 50°C. The pH value of the nickel sulfamate bath preferably has a value in the range of 3 to 4. The production of the phosphate-containing nickel layer 170 is carried out by chemical deposition in a bath with phosphate-containing nickel, wherein the bath temperature preferably has a value in the range of 80°C to 95°C. The phosphate content preferably has a value in the range of 5% to 50%, particularly in the range of 7% to 11%. This is also referred to as high-phosphorus nickel.

[0041] The palladium layer 172 is produced by chemical deposition in a palladium bath, the bath temperature preferably being in the range of 30°C to 50°C. The pH value of the palladium bath is preferably in the range of 7 to 9. The ruthenium layer 174 is produced by chemical deposition in a ruthenium bath, the bath temperature preferably being in the range of 40°C to 70°C. The pH value of the ruthenium bath is preferably in the range of 0.1 to 2, particularly in the range between 0.9 and 2.

[0042] Alternatively, the zincate pickling layer 166, the nickel layer 168, the phosphate-containing nickel layer 170, the palladium layer 172, and / or the ruthenium layer 174 can be produced by electroplating processes, wherein, for producing the palladium layer in an electroplating bath, a maximum current flow in the range of 0.3 A / dm² to 1.5 A / dm² of the cathode area is preferably generated when the base body 310 forms the cathode. For producing the ruthenium layer in an electroplating bath, a maximum current flow in the range of 0.3 A / dm² to 2.5 A / dm² of the cathode area is generated, with the base body 310 forming the cathode.

[0043] As an alternative to the layer thicknesses already mentioned, the zincate pickling layer 166 can have a thickness in the range of 100 nm to 300 nm. The nickel layer 168 produced can have a layer thickness in the range of 2 µm to 4 µm. The phosphate-containing nickel layer 170 can have a layer thickness in the range of 10 µm to 20 µm. The palladium layer 172 can have a layer thickness of 0.1 µm to 0.6 µm. The ruthenium layer produced can have a layer thickness in the range of 0.3 µm to 2 µm, in particular in the range of 0.1 µm to 0.8 µm or in the range of 0.8 µm to 1.5 µm.

[0044] The palladium layer 172 serves in particular as a corrosion protection layer. The nickel layer 168 is preferably highly corrosion-resistant and forms a closed layer on the zinc pickling layer 166.

[0045] Figure 6 shows a process flow chart 400 for producing the protective layer 312 according to Figure 5In a first step S40, the base body 310 is blasted with corundum. In other embodiments, the base body 310 can be pretreated in another suitable way. In particular, other types of corundum and other grain sizes can be used. Chemical pretreatment is also possible. In the present case, corundum with a grain size of 220 µm is used for blasting the base body 310.

[0046] In the next step, S42, the zincate pickling layer 166 is applied to the base body 310 in a zincate pickling bath by chemical deposition. Then, in step S44, a nickel layer 168 is electrolytically deposited onto the zincate pickling layer 166 in a nickel sulfamate bath. In step S46, a phosphate-containing nickel layer 170 is then applied to the nickel layer 168 by chemical deposition in a bath. In step S48, a palladium layer 172 is then applied to the phosphate-containing nickel layer 170 in a palladium bath by chemical deposition. Finally, in step S50, the ruthenium layer 174 is produced on the palladium layer 172 by chemical deposition in a ruthenium bath. The ruthenium layer 174 then forms the outer surface of the protective layer 312 for contact with the recording medium 120.

[0047] The use of ruthenium-coated base bodies 310 for transport rollers 300 reliably prevents contamination of the roller surface 176 with ink and / or dirt. To ensure this, the base body 310 is first sandblasted with corundum using a simple coating process. This increases the surface roughness and simultaneously smooths any rough peaks on the surface of the base body 310. The use of corundum results in a uniformly rough surface without sharp or pointed edges. The pre-treated base body 310 is then coated with a thin layer of ruthenium. This ruthenium layer has excellent anti-adhesive properties and high hardness. Due to the targeted surface treatment and the ruthenium coating, the results achieved are superior to those of transport rollers with a Teflon coating.

[0048] Teflon is a relatively soft material, which is why transport rollers with a Teflon coating wear out after a certain period and completely lose their non-stick properties. Therefore, Teflon-coated rollers are not wear-resistant and must be replaced regularly by a service technician. Depending on the recording medium used (120) or the type of paper being printed, these rollers can wear out sooner or later, which also poses a risk to the user of the printing device (100, 200) of producing waste paper. Ruthenium-coated transport rollers (300) are wear-free and can be used for the entire lifespan of the printer or printing device (100, 200). Ruthenium-coated transport and deflection rollers (300) are not only significantly cheaper to manufacture, but their wear-free design also contributes to a significant reduction in service costs and process stability for the user. Reference symbol list

[0049] 100, 200 Inkjet printing device 110, 112 Inkjet printer 114, 214 Flip unit 116 Input 118 Output 120 Recording medium 122, 124, 126, 224-240, 300 Transport roller 125, 127 Protective layer 210, 212 Printing module 216, 220 Printing unit 218, 222 Drying unit 166 Zinc pickling 168 Nickel layer 170 Phosphorus-containing nickel layer 172 Paladium layer 174 Ruthenium layer 176 Surface 310 Base body 312 Protective layer 400 Drain S40-S50 Process steps P1 Transport direction of the recording medium

Claims

1. Transport roller (122, 124, 126, 232-240, 300) for transporting a recording medium (120), wherein the transport roller (122, 124, 126, 232-240, 300) comprises a base body (310), wherein a protective layer (125, 127, 312) is formed on at least part of the outer surface of the base body (310), and wherein the protective layer (125, 127, 312) comprises at least one ruthenium layer (174), characterized in that the protective layer (125, 127, 312) comprises at least one zinc oxide layer (166) arranged between the ruthenium layer (174) and the base body (310).

2. Transport roller according to claim 1, characterized in that the transport roller (124, 126, 236, 238) contacts the side of the recording medium (120) on which the dried print image is located.

3. Transport roller according to one of the preceding claims, characterized in that the protective layer (125, 127, 312, 174) directly contacts the recording medium (120).

4. Method for producing a protective layer (125, 127, 312) on a part of the surface (176) of a base body (310) of a transport roller (300) for transporting the recording medium (120) downstream, a drying unit (218) for drying an inkjet print image printed on the recording medium (120) is arranged, in which a protective layer (125, 127, 312) comprising at least one ruthenium layer (174) is produced on the part of the surface (176) of the base body (310) of the transport roller (300), characterized in that the method comprises the following steps: the base body (310) is blasted with corundum before the ruthenium layer (174) or another layer (166 to 172) is applied, wherein the corundum preferably has a grain size of 200 µm to 240 µm and is preferably high-grade corundum, and the base body (310) is treated by chemical deposition in a zinc pickling bath or by an electroplating process before the ruthenium layer (174) or another layer (166 to 172) is applied and after blasting with corundum to produce a zinc pickling layer (166).

5. Method according to claim 4, wherein, if a zinc pickling bath is used, the temperature of the zinc pickling bath has a value in the range from 10°C to 25°C and / or the treatment duration in the bath is in the range from 60 s to 120 s.

6. Method according to one of the above claims 4 or 5, wherein, after the zinc pickling layer (166) has been produced, the base body (310) is treated to produce a nickel layer (168) by chemical deposition in a nickel sulphamate bath or by an electroplating process.

7. Method according to claim 6, wherein the temperature of the nickel sulphamate bath has a value in the range from 30°C to 50°C and / or the pH value is in the range from 3 to 4.

8. Method according to claim 6, wherein a maximum current flow in the range of 0.3 A / dm2 to 2.5 A / dm2 cathode area is generated in the galvanic bath, wherein the base body (310) preferably forms the cathode.

9. Method according to one of the above methods 4 to 8, wherein the base body (310) is treated after the nickel layer (168) has been produced in order to produce a phosphate-containing nickel layer (170) by chemical deposition in a bath containing phosphate-containing nickel or by an electroplating process.

10. Method according to claim 9, wherein the temperature of the bath containing phosphate-containing nickel has a value in the range from 80°C to 95°C and / or the phosphate content is in the range from 5% to 50%, in particular in the range from 7% to 11%.

11. Method according to claim 9, wherein the base body (310), after the phosphate-containing nickel layer has been produced, is treated by chemical deposition in a palladium bath or by an electroplating process to produce a palladium layer (172).

12. Method according to claim 11, wherein the temperature of the palladium bath has a value in the range from 30°C to 50°C and / or the pH value is in the range from 7 to 9.

13. Method according to claim 11, wherein the base body (310) is treated by chemical deposition in a ruthenium bath or by an electroplating process after the palladium layer (172) has been produced in order to apply the ruthenium layer (174).

14. Method according to claim 13, wherein the temperature of the ruthenium bath has a value in the range from 40°C to 70°C and / or the pH value is in the range from 0.1 to 2, in particular in the range between 0.9 and 2.

15. Method according to claim 13, wherein a ruthenium layer (174) is produced in an electroplating bath, wherein a maximum current flow in the range from 0.3 A to 1.5 A / dm2 cathode surface is produced in the electroplating bath, wherein the base body (310) forms the cathode.

16. Method according to at least one of claims 13 to 15, characterized in that the zinc pickling layer (166) produced has a thickness in the range from 100 nm to 300 nm, in particular a thickness of 200 nm, and / or that the nickel layer (168) produced has a thickness in the range from 2 µm to 4 µm, in particular a thickness of 3 µm, and / or that the phosphate-containing nickel layer (170) produced has a thickness in the range from 10 µm to 20 µm, in particular a thickness of 15 µm, and / or that the palladium layer (172) produced has a thickness in the range from 0.1 µm to 0.6 µm, in particular in the range from 0.1 µm to 0.5 µm, and / or that the ruthenium layer (174) produced has a thickness in the range from 0.3 µm to 2 µm, in particular in the range from 0.1 µm to 0.8 µm or 0.8 µm to 1.5 µm.