Method of printing an image on a metallic surface, particularly on a coin surface

Description

[0001] The invention relates to printing generally and more particularly to printing on metal objects such as coins.

[0002] It is known to print images on metal substrates. A number of systems and methods are known for applying ink on a metal surface. EP0209896 discloses a method and apparatus for decorating metal or plastic containers. US2002090456 teaches a method to print on strips of metal using computer controlled printing heads. GB2373217 discloses an inkjet printing system having print heads which utilize at least two different print head technologies. WO01920 discloses a paint composition formulation which allows metal coils to be decorated with multi-color complex designs. EP1120248 teaches a printing plate and method for its preparation, which forms a film of a desired image on a substrate medium for printing. EP1629977 describes how a printing plate can be roughened up in order for the polymer film to have good adhesion. US2004194235 describes a process to etch to a defined depth by using a laser and to fill the depth with a colored sealer. Finally EP1084830 discloses a method of roughening a plate surface using an electrochemical method.

[0003] Typically, it is necessary to coat the metal substrate with a thermoplastic or thermoset material prior to application of ink. It is further known to transfer the ink first to an intermediate carrier and subsequently transfer the ink from the carrier to the coated substrate. See, for example, U.S. Pat. No. 5,994,264 (Sherman et al.).

[0004] In particular, it is known to apply paint or ink to a metal coin using a silk screen process. While high quality images may be produced by such processes, adhesion of the image to the coin surface is not adequate to provide sufficient durability to make such coins suitable for public circulation.

[0005] A need exists for an efficient and low-cost method of printing images on metal surfaces such that the image demonstrates good adhesion to the metal surface. There is a particular need for a method of printing images on a face of a metal coin, wherein the image demonstrates sufficient durability to make the printed coin suitable for public circulation.

[0006] In a first aspect, the invention is a method of printing on a metal surface comprising the steps of providing a metal surface, forming a plurality of macropores on at least a portion of the metal surface, and forming a plurality of micropores within the macropores. The metal surface is cleaned, and a first ink having a first color is applied to the macropores and micropores to form at least one image on the metal surface. The ink is dried.

[0007] Preferably, the metal surface is part of a coin. Additional inks may be applied. Preferably, the first ink and any additional inks are solvent-based and are applied using inkjet printers. The drying process is preferably accomplished by blowing air across the metal surface. The method further preferably comprises a step of inspecting the metal surface to ensure correct orientation of the metal surface and a step of inspecting the metal surface to ensure proper quality of the printed image. The method may include a step of applying a substantially transparent top coat over the first and any additional inks. Preferably, the macropores are in the range of about 0.1 to 0.5 millimeter across and in the range of about 0.01 to 0.05 millimeter deep and the micropores are in the range of approximately 0.01 micrometres (microns) to 15 micrometres (microns) deep. The macropores may be formed in a stamping operation and the micropores may be formed in a sandblasting operation.

[0008] In a second aspect, the invention is a method of printing an image on at least a portion of a coin surface. The method comprises a first step of providing a metal coin having a first side and a second side. A plurality of macropores are formed on at least a portion of the first side. A plurality of micropores are formed at least within the macropores. At least the first side is cleaned to provide a substantially clean surface. The first side is inspected to ensure correct orientation of the coin. A first inkjet printer is used to apply a first ink having a first color to the macropores and micropores to form a first image on the first side. The first ink is air dried. A second inkjet printer is used to apply a second ink having a second color to the macropores and micropores. The second ink is air dried. A top coat of lacquer is applied to cover the first and second inks using a third inkjet printer. The top coat is air dried. The method is not limited to two colors, but may involve only one color, or more than two colors, excluding the top coat.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] For the purpose of illustrating the invention, there is shown in the drawings a form of the invention which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:

Figure 1 is a diagram of the steps of a method of printing on a metal surface in accordance with the present invention.

Figure 2 is a plan view of a first side of a coin having a printed surface produced in accordance with the method of Figure 1.

Figure 3 is a cross-sectional view of the coin of Figure 2, taken along line 3-3 of Figure 2.

Figure 4 is an enlarged detail view of the printed surface of the coin of Figure 2, showing macropores and micropores produced in accordance with the method of Figure 1.

Figures 5 through 13 are plan views of alternative patterns of macropore construction in accordance with the method of Figure 1.

Figures 14 and 15 are cross-sectional views showing alternative macropore construction in accordance with the method of Figure 1.

[0010] Referring to the figures, wherein like numerals are used to indicate like elements throughout, there is shown in Figure 1 a diagram of the steps of a method, identified generally by reference numeral 10, of printing on a metal surface in accordance with the present invention. Figures 2-4 illustrate a coin 100 produced by the method 10. The coin 100 includes a printable surface 108 having a plurality of macropores 110 and micropores 112, described in detail below. Figures 5-15 illustrate a few of the various ways in which the macropores 110 may be constructed.

[0011] The method of printing on a metal surface 10 will be described in the context of producing the coin 100. However, it will be recognized that the method 10 is applicable to metallic surfaces generally, and is not limited in application to coins. The method 10 is, however, especially well-suited for providing printed images on coins.

[0012] With reference to Figures 1-4, the method 10 comprises a first step 12 of providing a metal surface. The metal surface may be, for example, a first side 102 of the metal coin 100. The metal coin 100 includes the first side 102 and a second side 104. In the preferred embodiment illustrated, the first side 102 is provided with embossed indicia 106 surrounding the printable surface 108.

[0013] In a second step 14, a plurality of macropores 110 are formed on at least a portion of the metal surface (preferably, the first side 102). Preferably, the macropores 110 are formed using conventional metalworking techniques, such as stamping. With reference to Figures 4, 14, and 15, the macropores have a width A in the range of approximately 0.1 to 0.5 millimeters and a depth C in the range of 0.01 to 0.10 millimeters. Preferably, the macropores 110 are separated from one another by a distance B in the range of 0.0 to 0.3 millimeters.

[0014] The macropores 110 may be formed in a wide array of patterns. With reference to Figures 4 and 5, in a first pattern 130, the macropores 110 are formed as separate generally circular indentations of a generally uniform diameter. With reference to Figures 6-13, second through ninth patterns 132 - 146 provide both discrete, localized indentations similar to the first pattern 130, as well as extended indented channels. Other patterns are possible.

[0015] Furthermore, the macropores 110 may be formed in a wide array of cross-sectional profiles. With reference again to Figures 4 and 5, in a first cross-sectional profile 150, the macropores 110 are provided with a semi-circular cross-sectional profile. Furthermore, and with reference to Figure 14, in a second cross-sectional profile 152, the macropores 110 may be provided with compound shape having a combination of radiused and linear edges. Still further, with reference to Figure 15, the macropores 110 may be provided with a third, generally triangular, cross-sectional profile 154. The first through third cross-sectional profiles are illustrative of only three of the many geometries possible.

[0016] With particular reference to Figures 1 and 4, in a third step 16 a plurality of micropores 112 are formed within and adjacent to the macropores 110. The micropores 112 are characterized by dimensions much smaller than the macropores, ranging in sizes (depth and breadth) from 0.01 micrometre (micron) to 15 micrometres (microns). The micropores 112 average in size from around 0.5 micrometre (micron) to 5.0 micrometre (microns). The micropores 112 are preferably produced by a sandblasting process or by a lasering process.

[0017] With continued reference to Figure 1, in a fourth step 18 the metal surface (preferably, the printable surface 108) is cleaned to remove any debris on the surface accumulated during processing, including any lubricants. A clean surface improves adhesion of ink subsequently applied to the surface. The surface is cleaned using conventional techniques known to those of ordinary skill in the art of metalworking.

[0018] Preferably, in a fifth step 20 the metal surface is inspected to ensure correct orientation of the metal surface relative to inkjet printing equipment, described further below. The fifth step 20 is necessary for objects such as the coin 100, which is preferably fed to the printing equipment by automated equipment, and which is fed to the printing equipment oriented randomly face up or face down. If there were no uncertainty in the orientation of the object being processed, the fifth step 20 could be omitted.

[0019] Preferably the fifth step 20 is performed using conventional automated pattern recognition equipment of a type known to those of ordinary skill in the art of automated manufacturing equipment. For example, a digital camera (not illustrated) could be coupled to a computer controller (not illustrated), providing a signal to the controller. The controller is provided with software adapted to determine from the signal the orientation of the object being processed. In particular, with respect to the coin 100, the software would recognize whether the first side 102 or second side 104 was properly oriented relative to the printing equipment. If not properly oriented, the controller would activate machinery of a type well known to those of ordinary skill in the art of automated manufacturing equipment to flip the coin 100 into the desired orientation.

[0020] With reference now to Figures 1 and 6, in a sixth step 22, a first ink 116 having a first color is applied to the macropores 110 and micropores 112 to form at least one image 114 on the printable surface 108. Preferably, the first ink 116 is a solvent-based ink having a solvent which evaporates very quickly, preferably within three or four seconds of exposure to air blowing past the printable surface 108 at a moderate velocity (for example, 10 feet per second). In particular, an alcohol ketone based ink, such as the inks available from Imaje France of Bourg Les Valence, France, having product codes FT316 and 5130, have been found to be particularly effective.

[0021] The first ink 116 is preferably applied to the printable surface 108 using a first inkjet printer (not illustrated). The first inkjet printer is preferably a piezoelectric-type inkjet printer. The first inkjet printer is conventional. Preferably a Model S8 Series Master available from Image France is used.

[0022] In a seventh step 24, the ink is dried in a first air tunnel (not illustrated) where air is circulated at a moderate velocity to evaporate the solvent and dry the first ink 116. As indicated above, the metal object (preferably, the coin 100) moves through the first air tunnel in three to four seconds. The air need not be heated above the ambient temperature within the processing plant.

[0023] Preferably in an eighth step 26, a second ink 120 having a second color is applied to the macropores 110 and micropores 112 on the metal surface (the printable surface 108). The second ink 120 forms a second image 118, which preferably cooperates with the first image 114. In the particular embodiment of the coin 100 illustrated, the first image 114 and second image 118 together form a representation of a poppy flower.

[0024] Preferably, the second ink 120 is also solvent-based. It has been found to be desirable that the first and second inks 116, 120 be based on different solvents. Otherwise, when the second ink 120 is applied, the solvent contained therein tends to re-wet and blur the first image 114. The second ink 120 is preferably applied with a second inkjet printer (not illustrated) similar to the first inkjet printer (not illustrated). In a ninth step 28, the second ink 120 is air-dried, preferably in a manner similar to the first ink 116, as described in the seventh step 24.

[0025] It will be recognized that the method 10 is not limited to application of only two inks. Additional printing stations applying additional inks along with additional drying tunnels could be provided.

[0026] With reference now to Figures 1 and 4, in a tenth step 30, a substantially transparent top coat 122 is applied to at least substantially cover the first ink 116, and second ink 120 and other additional inks, if provided. Preferably, the top coat 122 is a substantially transparent lacquer having a nitrocellulose base resin. This lacquer is commercially available from sources including Imaje France, under the product code 5553. The preferred thickness of the top coat 122 is in the range of about 1 to 2 microns. Preferably, the tenth step 30 is performed using a third inkjet printer (not illustrated) of a type similar to the first and second inkjet printers. In an eleventh step 32, the top coat 122 is air-dried, preferably in a manner similar to that described above for the seventh and ninth steps 24 and 28.

[0027] Alternatively, it will be recognized that application of the top coat 122 could be accomplished using other materials and techniques. For example, the top coat 122 could be a transparent coating capable of being cured by exposure to ultraviolet radiation. Other types of heat sensitive top coats 122 could be used, including a polyurethane coating. Still further, the top coat 122 could either be colorless, or could be colored, while still being at least substantially transparent.

[0028] Finally, in a twelfth step 34, the first and second printed images 114, 118 are inspected for acceptable quality by automated pattern recognition equipment of a type similar to that described above relative to the fifth step 20.

[0029] It will be recognized by those of ordinary skill in the pertinent art that one or more of the foregoing twelve steps may be omitted. For example, the twelfth step 34, while desirable, need not be performed.

[0030] An efficient and low-cost method of printing images on metal surfaces is thus disclosed. In particular, an efficient and low-cost method of printing images on a face of a metal coin, wherein the image demonstrates sufficient durability and adhesion to the coin surface to make the printed coin suitable for public circulation, is disclosed.

Claims

1. A method of printing on a metal surface comprising the steps of:

providing a metal surface;

forming a plurality of macropores on at least a portion of the metal surface, wherein the macropores are in the range of about 0.1 to 0.5 millimeter across and in the range of about 0.01 to 0.10 millimeter deep;

forming a plurality of micropores within the macropores, wherein the micropores are in the range of approximately 0.01 micrometres to 15 micrometres in depth and breadth;

cleaning the metal surface;

applying a first ink having a first color to the macropores and micropores to form at least one image on the metal surface; and

drying the first ink.

2. The method of printing on a metal surface of claim 1, wherein the metal surface is part of a coin.

3. The method of printing on a metal surface of either claim 1 or claim 2, wherein the step of applying the ink is performed by an inkjet printer.

4. The method of printing on a metal surface of claim 3, wherein the inkjet printer is a piezoelectric inkjet printer.

5. The method of printing on a metal surface of any one of claims 1 to 4, wherein the ink is solvent- based.

6. The method of printing on a metal surface of claim 5, wherein the step of drying the ink includes a step of blowing air across the metal surface to evaporate a solvent in the solvent-based ink.

7. The method of printing on a metal surface of any one of claims 1 to 6 further comprising a step of applying a second ink to the macropores and micropores on the metal surface.

8. The method of printing on a metal surface of claim 7, wherein the second ink has a second color different from the first color.

9. The method of printing on a metal surface of either claim 7 or claim 8, wherein the first ink and the second ink are applied with first and second inkjet printers, respectively.

10. The method of printing on a metal surface of any one of claims 7 to 9, wherein the first ink and the second ink are solvent-based, and the first ink includes a first solvent and the second ink includes a second solvent.

11. The method of printing on a metal surface of any one of claims 1 to 10 further comprising a step of inspecting the metal surface to ensure correct orientation of the metal surface.

12. The method of printing on a metal surface of claim 11 further comprising a step of inspecting the metal surface to ensure proper quality of the printed image.

13. The method of printing on a metal surface of claim 12, wherein the steps of inspecting the metal surface and inspecting the image are performed using automated pattern recognition devices.

14. The method of printing on a metal surface of any one of claims 1 to 13 further comprising a step of applying a substantially transparent top coat to at least substantially cover the at least one image.

15. The method of printing on a metal surface of claim 14, wherein the top coat is a substantially transparent lacquer.

16. The method of printing on a metal surface of either claim 14 or claim 15, wherein the step of applying the top coat is performed using a third inkjet printer.

17. The method of printing on a metal surface of any one of claims 1 to 16, wherein the spacing between the macropores is in the range of 0.0 millimeter to about 0.30 millimeter.

18. The method of printing on a metal surface of any one of claims 1 to 17, wherein the step of forming the macropores is performed in a stamping operation and the step of forming the micropores is performed in one of a sandblasting operation or a lasering operation.

19. The method according to claim 2 further comprising the steps of:

applying a second ink to the macropores and micropores on the metal surface, where the second ink has a second color different from the first color;

drying the second ink;

inspecting the metal surface before application of the inks to ensure correct orientation of the metal surface;

applying a substantially transparent top coat to at least substantially cover the at least one image;

wherein the first and second inks are applied with first and second inkjet printers respectively and the top coat is applied using a third inkjet printer.

20. The method according to claim19, wherein the cleaning of the metal surface provides a substantially clean surface, the drying of the first and second inks is air drying and the top coat is a lacquer.

21. The method of claim 20 further comprising the steps of using at least a third inkjet printer to apply at least a third ink having at least a third color to the macropores and micropores and air drying the at least third ink.

Ansprüche

1. Verfahren zum Drucken auf einer Metalloberfläche, das folgende Schritte umfasst:

das Bereitstellen einer Metalloberfläche;

das Ausbilden einer Vielzahl von Makroporen auf zumindest einem Abschnitt der Metalloberfläche, worin die Makroporen einen Durchmesser im Bereich von etwa 0,1 bis 0,5 mm und eine Tiefe im Bereich von etwa 0,01 bis 0,10 mm aufweisen;

das Ausbilden einer Vielzahl an Mikroporen innerhalb der Makroporen, worin die Mikroporen eine Tiefe und Breite im Bereich von etwa 0,01 µm bis 15 µm aufweisen;

das Reinigen der Metalloberfläche;

das Aufbringen einer ersten Druckfarbe mit einer ersten Farbe auf die Makroporen und Mikroporen, um zumindest ein Bild auf der Metalloberfläche zu erzeugen, und

das Trocknen der ersten Druckfarbe.

2. Verfahren zum Drucken auf einer Metalloberfläche nach Anspruch 1, worin die Metalloberfläche Teil einer Münze ist.

3. Verfahren zum Drucken auf einer Metalloberfläche nach Anspruch 1 oder 2, worin der Schritt des Aufbringens der Druckfarbe durch einen Tintenstrahldrucker erfolgt.

4. Verfahren zum Drucken auf einer Metalloberfläche nach Anspruch 3, worin der Tintenstrahldrucker ein piezoelektrischer Tintenstrahldrucker ist.

5. Verfahren zum Drucken auf einer Metalloberfläche nach einem der Ansprüche 1 bis 4, worin die Druckfarbe lösungsmittelbasiert ist.

6. Verfahren zum Drucken auf einer Metalloberfläche nach Anspruch 5, worin der Schritt des Trocknens der Druckfarbe einen Schritt umfasst, bei dem Luft auf die Metalloberfläche geblasen wird, um das Lösungsmittel in der lösungsmittelbasierten Druckfarbe zu verdampfen.

7. Verfahren zum Drucken auf einer Metalloberfläche nach einem der Ansprüche 1 bis 6, das weiters einen Schritt umfasst, bei dem eine zweite Druckfarbe auf die Makroporen und Mikroporen auf der Metalloberfläche aufgebracht wird.

8. Verfahren zum Drucken auf einer Metalloberfläche nach Anspruch 7, worin die zweite Druckfarbe eine zweite Farbe aufweist, die sich von der ersten Farbe unterscheidet.

9. Verfahren zum Drucken auf einer Metalloberfläche nach Anspruch 7 oder 8, worin die erste Druckfarbe und die zweite Druckfarbe mit einem ersten bzw. einem zweiten Tintenstrahldrucker aufgebracht werden.

10. Verfahren zum Drucken auf einer Metalloberfläche nach einem der Ansprüche 7 bis 9, worin die erste Druckfarbe und die zweite Druckfarbe lösungsmittelbasiert sind und die erste Druckfarbe ein erstes Lösungsmittel umfasst und die zweite Druckfarbe ein zweites Lösungsmittel umfasst.

11. Verfahren zum Drucken auf einer Metalloberfläche nach einem der Ansprüche 1 bis 10, das weiters einen Schritt umfasst, bei dem die Metalloberfläche geprüft wird, um eine korrekte Ausrichtung der Metalloberfläche sicherzustellen.

12. Verfahren zum Drucken auf einer Metalloberfläche nach Anspruch 11, das weiters einen Schritt umfasst, bei dem die Metalloberfläche geprüft wird, um eine angemessene Qualität des gedruckten Bildes sicherzustellen.

13. Verfahren zum Drucken auf einer Metalloberfläche nach Anspruch 12, worin der Schritt des Überprüfens der Metalloberfläche und der Schritt des Überprüfens des Bilds unter Verwendung von automatischen Mustererkennungsvorrichtungen durchgeführt werden.

14. Verfahren zum Drucken auf einer Metalloberfläche nach einem der Ansprüche 1 bis 13, das weiters einen Schritt umfasst, bei dem eine im Wesentlichen transparente Deckschicht auf gebracht wird, um das zumindest eine Bild zumindest im Wesentlichen zu bedecken.

15. Verfahren zum Drucken auf einer Metalloberfläche nach Anspruch 14, worin die Deckschicht ein im Wesentlichen transparenter Lack ist.

16. Verfahren zum Drucken auf einer Metalloberfläche nach Anspruch 14 oder 15, worin der Schritt des Aufbringens der Deckschicht unter Einsatz eines dritten Tintenstrahldruckers durchgeführt wird.

17. Verfahren zum Drucken auf einer Metalloberfläche nach einem der Ansprüche 1 bis 16, worin der Abstand zwischen den Makroporen im Bereich von 0,0 mm bis etwa 0,30 mm liegt.

18. Verfahren zum Drucken auf eine Metalloberfläche nach einem der Ansprüche 1 bis 17, worin der Schritt des Ausbildens der Makroporen in einem Stanzvorgang erfolgt und der Schritt des Ausbildens der Mikroporen in einem Sandstrahlvorgang oder einem Laservorgang erfolgt.

19. Verfahren nach Anspruch 2, das weiters folgende Schritte umfasst:

das Aufbringen einer zweiten Druckfarbe auf die Makroporen und Mikroporen auf der Metalloberfläche, wobei die zweite Druckfarbe eine zweite Farbe aufweist, die sich von der ersten Farbe unterscheidet;

das Trocknen der zweiten Druckfarbe;

das Überprüfen der Metalloberfläche vor dem Aufbringen der Druckfarben, um eine korrekte Ausrichtung der Metalloberfläche sicherzustellen;

das Aufbringen einer im Wesentlichen transparenten Deckschicht, um das zumindest eine Bild zumindest im Wesentlichen zu bedecken;

worin die erste und die zweite Druckfarbe mit einem ersten bzw. einem zweiten Tintenstrahldrucker aufgebracht werden und die Deckschicht unter Einsatz eines dritten Tintenstrahldruckers aufgebracht wird.

20. Verfahren nach Anspruch 19, worin das Reinigen der Metalloberfläche eine im Wesentlichen reine Oberfläche bereitstellt, das Trocknen der ersten und zweiten Druckfarbe durch Lufttrocknen erfolgt und die Deckschicht ein Lack ist.

21. Verfahren nach Anspruch 20, das weiters den Schritt des Einsatzes zumindest eines dritten Tintenstrahldruckers zum Aufbringen zumindest einer dritten Druckfarbe mit zumindest einer dritten Farbe auf die Makroporen und Mikroporen und des Lufttrocknens der zumindest dritten Druckfarbe umfasst.

Revendications

1. Procédé d'impression sur une surface métallique comprenant les étapes de:

réaliser une surface métallique;

former une pluralité de macropores sur au moins une portion de la surface métallique, où les macropores sont dans la plage d'environ 0,1 à 0,5 millimètre de largeur et dans la plage d'environ 0,01 à 0,10 millimètre de profondeur;

former une pluralité de micropores dans les macropores, où les micropores sont dans la plage d'approximativement 0,01 micromètre à 15 micromètres en profondeur et largeur;

nettoyer la surface métallique;

appliquer une première encre ayant une première couleur aux macropores et micropores pour former au moins une image sur la surface métallique; et

sécher la première encre.

2. Procédé d'impression sur une surface métallique selon la revendication 1, dans lequel la surface métallique est une partie d'une pièce de monnaie.

3. Procédé d'impression sur une surface métallique selon l'une quelconque des revendications 1 ou 2, dans lequel l'étape d'application d'encre est exécutée par une imprimante à jet d'encre.

4. Procédé d'impression sur une surface métallique selon la revendication 3, dans lequel l'imprimante à jet d'encre est une imprimante à jet d'encre piézoélectrique.

5. Procédé d'impression sur une surface métallique selon l'une quelconque des revendications 1 à 4, dans lequel l'encre est à base de solvant.

6. Procédé d'impression sur une surface métallique selon la revendication 5, dans lequel l'étape de séchage de l'encre comporte une étape de soufflage d'air sur la surface métallique pour l'évaporation d'un solvant dans l'encre à base de solvant.

7. Procédé d'impression sur une surface métallique selon l'une quelconque des revendications 1 à 6, comprenant en outre une étape consistant à appliquer une deuxième encre aux macropores et micropores sur la surface métallique.

8. Procédé d'impression sur une surface métallique selon la revendication 7, dans lequel la deuxième encre a une deuxième couleur différente de la première couleur.

9. Procédé d'impression sur une surface métallique selon l'une quelconque des revendications 7 ou 8, dans lequel la première encre et la deuxième encre sont appliquées avec des première et deuxième imprimantes à jet d'encre, respectivement.

10. Procédé d'impression sur une surface métallique selon l'une quelconque des revendications 7 à 9, dans lequel la première encre et la deuxième encre sont à base de solvant, et la première encre comporte une premier solvant et la deuxième encre comporte un deuxième solvant.

11. Procédé d'impression sur une surface métallique selon l'une quelconque des revendications 1 à 10, comprenant en outre une étape consistant à inspecter la surface métallique pour assurer une orientation correcte de la surface métallique.

12. Procédé d'impression sur une surface métallique selon la revendication 11, comprenant en outre une étape consistant à inspecter la surface métallique pour assurer une qualité correcte de l'image imprimée.

13. Procédé d'impression sur une surface métallique selon la revendication 12, dans lequel les étapes consistant à inspecter la surface métallique et à inspecter l'image sont exécutées en utilisant des dispositifs de reconnaissance de motif automatiques.

14. Procédé d'impression sur une surface métallique selon l'une quelconque des revendications 1 à 13, comprenant en outre une étape consistant à appliquer une couche de finition sensiblement transparente pour couvrir au moins sensiblement la au moins une image.

15. Procédé d'impression sur une surface métallique selon la revendication 14, dans lequel la couche de finition est une laque sensiblement transparente.

16. Procédé d'impression sur une surface métallique selon l'une quelconque des revendications 14 ou 15, dans lequel l'étape consistant à appliquer la couche de finition est exécutée en utilisant une troisième imprimante à jet d'encre.

17. Procédé d'impression sur une surface métallique selon l'une quelconque des revendications 1 à 16, dans lequel l'espacement entre les macropores est dans la plage de 0,0 millimètre à environ 0,30 millimètre.

18. Procédé d'impression sur une surface métallique selon l'une quelconque des revendications 1 à 17, dans lequel l'étape de formation des macropores est exécutée par une opération d'estampage, et l'étape de formation des micropores est exécutée selon l'une parmi une opération de sablage ou une opération au laser.

19. Procédé selon la revendication 2, comprenant en outre les étapes de:

appliquer une deuxième encre aux macropores et micropores sur la surface métallique, où la deuxième encre possède une deuxième couleur différente de la première couleur;

sécher la deuxième encre;

inspecter la surface métallique avant l'application des encres pour assurer une orientation correcte de la surface métallique;

appliquer une couche de finition sensiblement transparente pour couvrir au moins sensiblement la au moins une image;

où les première et deuxième encres sont appliquées avec les première et deuxième imprimantes à jet d'encre respectivement, et la couche de finition est appliquée en utilisant une troisième imprimante à jet d'encre.

20. Procédé selon la revendication 19, dans lequel le nettoyage de la surface métallique réalise une surface sensiblement propre, le séchage des première et deuxième encres est un séchage à air et la couche de finition est une laque.

21. Procédé selon la revendication 20, comprenant en outre les étapes consistant à utiliser au moins une troisième imprimante à jet d'encre pour appliquer au moins une troisième encre ayant au moins une troisième couleur aux macropores et micropores et le séchage à air de la au moins troisième encre.

Drawing