APPARATUS AND METHOD FOR FORMING HIGH DEFINITION LITHOGRAPHIC IMAGES ON CONTAINERS

Abstract

The present invention relates to using soft secondary plates and specialty inks in a printing process. More specifically, the present invention relates to an apparatus and methods of using soft secondary plates made of a rubber comprising a saturated chain of polymethylene or a photopolymer material to decorate an exterior surface of cylindrical metallic containers with high definition graphics and other indicia.

Claims

1-20. (canceled)

21. An apparatus for forming a high-definition lithographic image on an exterior surface of a metallic container, comprising: a first plate cylinder; a first printing plate attached to a circumference of the first plate cylinder, the first printing plate including a first ink receiving region bordered by a non-ink receiving region; a first inker operable to transfer a first ink to the first ink receiving region of the first printing plate; a blanket cylinder; a flexible transfer plate affixed to the blanket cylinder, the flexible transfer plate including a first image surrounded by a relief region, wherein the relief region aligns with the non-ink receiving region of the first printing plate, wherein the blanket cylinder is operable to move the flexible transfer plate into contact with the first printing plate such that the first ink is transferred from the first ink receiving region to the first image on the flexible transfer plate; and a support cylinder operable to move the metallic container into contact with the flexible transfer plate, wherein the flexible transfer plate is configured to transfer the first ink to the exterior surface of the metallic container.

22. The apparatus of claim 21, wherein the relief region has a depth that is lower than a plane defined by a face portion of the flexible transfer plate.

23. The apparatus of claim 21, wherein the relief region is formed by removing material from the flexible transfer plate.

24. The apparatus of claim 21, wherein the first image on the flexible transfer plate is a positive image configured to transfer the first ink to the metallic container.

25. The apparatus of claim 24, wherein the flexible transfer plate is configured to transfer the first ink to define the first image on the exterior surface of the metallic container.

26. The apparatus of claim 25, wherein the flexible transfer plate is configured to form an un-inked area corresponding to the relief region surrounding the first ink on the exterior surface of the metallic container.

27. The apparatus of claim 21, wherein the flexible transfer plate is comprised of one of a photopolymer material and a saturated chain of polymethylene.

28. The apparatus of claim 27, wherein the saturated chain of polymethylene is an M-class rubber.

29. The apparatus of claim 27, wherein the saturated chain of polymethylene is an ethylene propylene diene monomer.

30. The apparatus of claim 27, wherein the saturated chain of polymethylene is an ethylene propylene rubber.

31. The apparatus of claim 27, wherein the first image is formed by a laser engraving process.

32. The apparatus of claim 21, wherein the flexible transfer plate is formed of a non-laminated material.

33. The apparatus of claim 21, wherein no image is formed in the first ink receiving region of the first printing plate.

34. The apparatus of claim 21, further comprising: a second plate cylinder; a second printing plate attached to a circumference of the second plate cylinder, the second printing plate including a second ink receiving region and a relief area that will not accept ink, wherein the relief area aligns with the non-ink receiving region of the first printing plate; and a second inker operable to transfer a second ink to the second ink receiving region of the second printing plate, wherein the second printing plate is configured to transfer the second ink to a third ink receiving region of the flexible transfer plate, and wherein the flexible transfer plate is configured to transfer the second ink to the exterior surface of the metallic container.

35. A method of decorating an exterior surface of a metallic container with an image, comprising: providing a first printing plate on a first plate cylinder of a decorator, the first printing plate including a first ink receiving region bordered by a non-ink receiving region; transferring a first ink from a first inker of the decorator to the first ink receiving region; transferring the first ink from the first ink receiving region to an image formed on a flexible transfer plate that is affixed to a blanket cylinder of the decorator, wherein the image on the flexible transfer plate is surrounded by a relief region that aligns with the non-ink receiving region of the first printing plate; and moving the flexible transfer plate into contact with the exterior surface of the metallic container, wherein the image defined by the first ink is transferred to the exterior surface of the metallic container.

36. The method of claim 35, wherein the relief region has a depth that is lower than a plane defined by a face portion of the flexible transfer plate.

37. The method of claim 35, wherein an un-inked area corresponding to the relief region of the flexible transfer plate forms an un-inked area surrounding the image on the exterior surface of the metallic container.

38. The method of claim 35, wherein the image is formed on the flexible transfer plate by a laser engraving process.

39. The method of claim 35, wherein the flexible transfer plate is comprised of one of a photopolymer material and a saturated chain of polymethylene.

40. The method of claim 35, further comprising: providing a second printing plate on a second plate cylinder of the decorator, the second printing plate including a second ink receiving region and a relief area that will not accept ink, wherein the relief area aligns with the non-ink receiving region of the first printing plate; transferring a second ink from a second inker of the decorator to the second ink receiving region of the second printing plate; transferring the second ink to a third ink receiving region of the flexible transfer plate; and transferring the second ink from the third ink receiving region to the exterior surface of the metallic container, wherein the metallic container is decorated with the second ink and with the image formed of the first ink.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the Summary of the Invention given above and the Detailed Description of the drawings given below, serve to explain the principles of these embodiments. In certain instances, details that are not necessary for an understanding of the disclosure or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein. Additionally, it should be understood that the drawings are not necessarily to scale.

[0064] FIG. 1A is a top plan view of a printing plate with an engraved or etched area according to one embodiment of the present invention;

[0065] FIG. 1B is a cross-sectional elevation view of the printing plate of FIG. 1A taken along line 1B;

[0066] FIG. 2A is a top plan view of a printing plate with a relief area according to an embodiment of the present invention;

[0067] FIG. 2B is a cross-sectional elevation view of the printing plate of FIG. 2A taken along line 2B;

[0068] FIG. 3A is a top plan view of a soft secondary plate before an image is formed thereon;

[0069] FIG. 3B is a side elevation view of the soft secondary plate of FIG. 3A;

[0070] FIG. 4A is a top plan view of a soft secondary plate with an image formed thereon according to one embodiment of the present invention;

[0071] FIG. 4B is a top plan view of a soft secondary plate with a second image formed thereon according to another embodiment of the present invention;

[0072] FIG. 4C is a cross-sectional elevation view of the soft secondary plate of FIG. 4B taken along line 4C;

[0073] FIG. 5 is a schematic illustration of one embodiment of a decorator of the present invention using soft secondary plates to decorate metallic containers;

[0074] FIG. 6A is a photograph of a soft secondary plate comprised of a photopolymer material with an image formed thereon according to various embodiments of the present invention;

[0075] FIG. 6B is an enlarged photograph of the image formed on the soft secondary plate of FIG. 6A;

[0076] FIG. 7A is a photograph of a metallic container decorated according to various embodiments of the present invention using the soft secondary plate of FIG. 6A;

[0077] FIG. 7B is an enlarged photograph of the metallic can of FIG. 7A;

[0078] FIG. 8 is a photograph of a soft secondary plate comprised of a photopolymer material with images formed thereon according to various embodiments of the present invention;

[0079] FIG. 9 is a photograph of a metallic container decorated according to various embodiments of the present invention using the soft secondary plate of FIG. 8;

[0080] FIG. 10A is an enlarged photograph of a first image formed on the metallic container of FIG. 9 using the soft secondary plate of FIG. 8; and

[0081] FIG. 10B is a second enlarged photograph of a second image formed on the metallic container of FIG. 9 using the soft secondary plate of FIG. 8.

[0082] To assist in the understanding of one embodiment of the present invention the following list of components and associated numbering found in the drawings is provided herein:

TABLE-US-00001 Number Component 2 Printing plate 4 Face portion 6 Back portion 8 Ink receiving region 10 Non-ink region 12 Relief area 14 Soft secondary plate 16 Ink receiving region 18 Image 20 Relief area 22 Screened area 24 Decorator 26 Plate cylinder 28 Inker 30 Rollers 32 Blanket cylinder 34 Metallic container 36 Conveyor 38 Support cylinder 40 Station for metallic container 42 Storage facility 44 Container surface 46 Non-inked portion 48 Varnish unit 50 Curing unit

DETAILED DESCRIPTION

[0083] The present invention has significant benefits across a broad spectrum of endeavors. It is the Applicant's intent that this specification and the claims appended hereto be accorded a breadth in keeping with the scope and spirit of the invention being disclosed despite what might appear to be limiting language imposed by the requirements of referring to the specific examples disclosed. To acquaint persons skilled in the pertinent arts most closely related to the present invention, a preferred embodiment that illustrates the best mode now contemplated for putting the invention into practice is described herein by, and with reference to, the annexed drawings that form a part of the specification. The exemplary embodiment is described in detail without attempting to describe all of the various forms and modifications in which the invention might be embodied. As such, the embodiments described herein are illustrative, and as will become apparent to those skilled in the arts, may be modified in numerous ways within the scope and spirit of the invention.

[0084] Although the following text sets forth a detailed description of numerous different embodiments, it should be understood that the detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims. To the extent that any term recited in the claims at the end of this patent is referred to in this patent in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term by limited, by implication or otherwise, to that single meaning.

[0085] Referring now to FIGS. 1A and 1B, a printing plate 2A is illustrated. The printing plate 2A has a face portion 4 and a back portion 6. One or more ink receiving regions 8 adapted to receive and transfer ink to a soft secondary plate are formed in the face portion 4 by any means known to those of skill in the art. The inked receiving regions 8 of the printing plate 2A transfer a single tone, image, type of ink, or text to the soft secondary plate during a printing process. One or more non-ink regions 10 may be formed in the printing plate. The non-ink regions 10 may be formed by engraving, cutting, etching, and/or removing selected portions from the face portion 4 of the printing plate 2A to form depressions in the face portion. Additionally or alternatively, non-ink regions 10 may be treated to be hydrophilic to prevent ink from adhering to the printing plate 2A as is known by those of skill in the art. The non-ink regions 10 will not receive or transfer ink to the soft secondary plate. Although the non-ink region 10 illustrated in FIG. 1A is rectangular, one skilled in the art will recognize that any shape of non-ink region can be formed on the printing plate 2A, such as a circle, square, or star, an irregular shape and/or combinations thereof. The size and the location of the non-ink region 10 may also be varied. The printing plate 2A may have a common content with the other printing plates 2 used in the printing process to form a final image that will be transferred first to the soft secondary plate and then to a metallic container.

[0086] Printing plates 2B may also be formed with a relief area 12, as illustrated in FIGS. 2A and 2B. The relief area 12 can be formed by removing a portion of the face portion 4 of the plate 2B. Additionally or alternatively, the relief area 12 can be formed or treated to be hydrophilic to prevent ink from adhering to the printing plate 2B. The relief area 12 will not accept ink and therefore will not transfer ink to the soft photopolymer plates. The size, location, and shape of the relief area 12 may align with the size, location, and shape of the non-ink region 10 of the printing plate 2A illustrated in FIGS. 1A and 1B. More than one relief area may be formed in each printing plate 2. Additionally or alternatively, printing plates 2 may include both relief areas 12 and non-ink regions 10. In one embodiment, one or more of the printing plates 2 include a face portion 4 comprising a photopolymer material. Images, non-ink regions 10, and relief areas 12 may be formed on the face portion 4 of a printing plate or blanket material comprising a photopolymer material as described below in conjunction with FIGS. 3 and 4.

[0087] After one or more of the ink receiving regions 8, non-ink regions 10, and/or relief areas 12 are formed on a printing plate 2, the plate 2 is attached to a plate cylinder of a decorator, discussed below in conjunction with FIG. 5. Optionally, more than one color of ink and one or more specialty inks may be used in conjunction with a corresponding inker in the printing process to form the final image. Each individual color of ink and type of specialty ink is applied by different plate cylinders. The printing plates of each plate cylinder will only receive one color or type of ink from an inker associated with each plate cylinder.

[0088] FIGS. 3A and 3B illustrate a soft secondary plate 14 before an image has been formed on the face portion 4 of the plate. Although the soft secondary plate 14 illustrated in FIGS. 3A and 3B has a generally rectangular shape, soft secondary plates are supplied in a varied of sizes and shapes that are suitable for use with the present invention. In one embodiment of the present invention, the soft secondary plate 14 has a thickness of about 0.04 inch to about 0.1 inch. In another embodiment, the thickness of the soft secondary plate is from about 0.060 inch to about 0.090 inch. In another embodiment, the soft secondary plate is about 0.05 inch thick. In still another embodiment, the soft secondary plate is about 0.0725 inch thick. As will be appreciated by those of skill in the art, soft secondary plates of any other suitable thicknesses may also be used with the present invention. Optionally, the soft secondary plates may include a Mylar backing. However, one of skill in the art will appreciate that backings of other materials, or no backing, may be used with the soft secondary plates 14. Further, an adhesive transfer tape or adhesive stickyback may be added to the back portion 6 of the soft secondary plate 14.

[0089] In one aspect of the present invention, at least the face portion 4 of the soft secondary plate 14 may be comprised of rubber comprising a saturated chain of polymethylene or other similar materials with similar physical properties. In one embodiment, the rubber comprises an M-class rubber. It will be appreciated by those of skill in the art that an M-class rubber refers to rubbers in American Society for Testing and Materials (ASTM) standard D-1418. In another embodiment, the rubber comprises an ethylene propylene diene monomer, known to those of skill in the art as EPDM rubber. EPDM rubber is a durable, synthetic rubber. In yet another embodiment, the rubber comprises an ethylene propylene rubber and is known to those of skill in the art as EPR and/or EPM rubber. In another aspect of the present invention, at least the face portion 4 of the soft secondary plate 14 may be comprised of pliable plastic materials.

[0090] In another aspect of the present invention, at least the face portion 4 of the soft secondary plate 14 may be comprised of a photopolymer material. Suitable soft photopolymer plates are commercially available from a variety of sources as will be appreciated by one skilled in the art. Examples of soft photopolymer plates used for high quality printing on flexible packaging are the Cyrel NOWS and the Cyrel DPR plates made by DuPont and described in DuPont Cyrel NOWS, Rugged, High-Performane Analog Plate, available at http://www2.dupont.com/Packaging_Graphics/en_US/assets/downloads/pdf/Cyrel_NOWS.pdf and DuPont Cyrel DPR, Robust Digital Plate for Highest Quality Printing, available at http://www2.dupont.com/Packaging_Graphics/en_US/assets/downloads/pdf/DP_Cyrel_DS_DPR_us_low.pdf, which are each incorporated herein by reference in their entireties.

[0091] In one embodiment, the soft photopolymer plates have a hardness of from about 40 durometers to about 110 durometers. In a preferred embodiment, the hardness of the soft photopolymer plates is from about 60 durometers to about 100 durometers. In another preferred embodiment, the hardness of the soft photopolymer plates is from about 50 durometers to about 90 durometers. However, soft photopolymer plates that are harder or softer may be used with the method of the present invention. In one embodiment, the hardness of the soft photopolymer plates is measured after the plates have been cured and an image formed thereon as described below.

[0092] The soft photopolymer plate may be made of any photo-curable material, whether made of a polymer or not. One example is a UV-curable material. Another example is made of a material cured by light of a different wavelength, not necessarily UV light. Although many such plates are made of polymer compositions today, the current invention is applicable to plates made of any material and composition that are curable by light of a desired wavelength. In one embodiment, the photopolymer plate is comprised of elastomers which are cured using a light-catalyzed photopolymerization process. In another embodiment, the photopolymer plate is comprised of chloroprene cross-linked with trimethylolpropane triacrylate. In still another embodiment, the photopolymer plate is comprised of styrene-isoprene rubber with a polyacrylate. Still other embodiments may use soft photopolymer plates comprised of other suitable light-curable materials known to those skilled in the art or developed in the future.

[0093] Soft photopolymer plates have primarily been used for creating high resolution graphics on flexible plastic packaging (such as soft plastic vegetable and produce bags), tags, labels, folding cartons, and tissue wrappers. Soft photopolymer plates are not known to have been used in the metallic container industry due to the significant challenges of high speed printing on an exterior surface of a metallic substrate.

[0094] Referring now to FIGS. 4A-4C, soft secondary plates 14 are illustrated with images 18 formed thereon. The face portions 4 of the soft secondary plates 14A, 14B include ink receiving regions 16. An image 18A of the word BALL is formed on the soft secondary plate 14A. An image 18B of a sports jersey is formed on the other soft secondary plate 14B.

[0095] The process of forming the image 18 to be printed onto the exterior surface of the metallic container on the soft secondary plates 14 depends on the material of the soft secondary plate. When the soft secondary plates 14 are comprised at least partially of rubber, the image 18 is formed on (or transferred to) the soft secondary plate 14 by any process known to one of skill in the art (or developed in the future) including, without limitation, a direct laser engraving (DLE) process, a mechanical or chemical etching or engraving process, an ink repelling process, a pressure forming process, or by a combination of processes.

[0096] In the DLE process, a portion of the rubber material of the soft secondary plate 14 is ablated, or otherwise removed, by a laser. The time required to form the image on the rubber soft secondary plate 14 varies based on the size and complexity of the image, the depth and shading of the image, and also upon the composition of the rubber of the soft secondary plate. In one embodiment, the processing time required to form the image 18 in the rubber using the DLE process is from approximately 10 minutes to approximately 3 hours. The rubber soft secondary plate 14 may be affixed to a cylindrical surface while the image is formed using the DLE process. The cylindrical surface has a radius of curvature approximately equal to the radius of curvature of the blanket cylinder of the decorator. Forming the image 18 in the rubber using the DLE process is similar to using a laser engraving and cutting system, such as an Epilog laser to burn an image in a substrate. However, the DLE process offers higher image resolutions and the ability to control the height of screened dots that compose the image (known as the dot deck height).

[0097] In the etching or engraving process, predetermined portions of the rubber of the soft secondary plate 14 are removed to form the image. In a mechanical etching or engraving process, a tool is used to remove the predetermined portions of the rubber. The tool may include a cutting tool, a rotating bit, an abrasive tool, a fluid tool, or any other type of tool operable to remove a predetermined amount of rubber from the face portion 4 of the soft secondary plate 14. The fluid tool may direct a high pressure stream into the face portion of the soft secondary plate. The high pressure stream of the fluid tool can include at least one of a gas, a liquid, and a solid selected to remove the rubber from the face portion of the soft secondary plate 14. Optionally, the tool may be heated to a predetermined temperature as the image is formed on the rubber soft secondary plate 14.

[0098] In a chemical etching or engraving process, a chemical is used to remove the predetermined portions of the rubber. A masking material may be applied to the rubber of the soft secondary plate 14 to ensure that the chemical only contacts and removes the predetermined portions of the rubber to form the image. The masking material is selected to adhere to the rubber and is inert with respect to the chemical to protect non-image areas of the rubber. In one embodiment, the masking material may be applied to the entire face portion of the soft secondary plate 14. The masking material is then selectively removed from the areas forming the image. In another embodiment, the masking material is only applied to non-image areas on the face portion 4 of the soft secondary plate. The chemical is then applied to the face portion 4 and contacts the image areas not protected by the masking material. After a predetermined amount of time, the chemical is removed or neutralized and the masking material is removed from the soft secondary plate 14. Optionally, the soft secondary plate 14 may be at least partially immersed in a bath of the chemical. In another embodiment, no masking material is used and the chemical is selectively applied to the predetermined portions of the rubber.

[0099] When the image is formed using the ink repelling process, predetermined portions of the rubber soft secondary plate 14 are adapted to be receptive or repellant to ink. In one embodiment, a chemical or a material that repels or attracts ink is applied to predetermined portions of the rubber of the soft secondary plate 14 to form the image. In another embodiment, before the image is formed on the soft secondary plate 14, the face portion 4 of the plate includes a coating that repels or attracts ink. Predetermined portions of the coating are selectively removed from the rubber soft secondary plate 14 to form the image. The image formed using the ink repelling process is comprised of areas that attract ink and other areas that repel ink. In one embodiment, the image may include areas that attract (or repel) at least one type of ink and repel (or attract) at least one other type of ink.

[0100] In the pressure forming process, the image is first formed on a surface of a master material. The master material may comprise a metal, a plastic, a photopolymer material, or any other suitable material. The rubber of the soft secondary plate 14 is pressed against the image on the master material for a predetermined amount of time to transfer the image from the master material to the rubber soft secondary plate 14. The soft secondary plate 14 with the image is then removed from the master material. The rubber of the soft secondary plate 14 and/or the master material may be heated before the soft secondary plate 14 is pressed against master material. In one embodiment, the soft secondary plate and the master material are heated to a temperature of approximately 310 F. In another embodiment, the soft secondary plate 14 and the master material are pressed together at a pressure of approximately 1,000 psi.

[0101] After the image 18 is formed on the rubber soft secondary plate 14, the soft secondary plate 14 may be cleaned by any suitable method to remove debris from the face portion 4. In one embodiment, a pressurized gas is used to remove the debris from the soft secondary plate 14. In another embodiment, the debris is removed from the soft secondary plate 14 with a liquid, such as water or a solvent.

[0102] When the image 18 is formed on the face portion 4 of the rubber soft secondary plate 14, the face portion 4 may have relief areas 20 that will not receive ink and images 18 that can receive ink. The image 18 formed on the rubber of the soft secondary plate 14 can be three dimensional and have different depths in the face portion 4. The image 18, or portions of the image, may have a depth of about 0.0009 inch to about 0.089 inch. In a more preferred embodiment, the depth of the image 18, or within portions of an image 18, is from approximately 0.001 inch to approximately 0.084 inch deep.

[0103] When the soft secondary plates 14 are comprised at least partially of a photopolymer material, the images 18A, 18B are formed of exposed and hardened material of the soft photopolymer plates with a computer to plate (CTP) process, a conventional plate exposure process, or any other suitable method. A piece of Mylar is generally used as a backing for the soft photopolymer plate 14, although other materials commonly known by one skilled in the art may also be employed as a backing. An image 18 to be printed onto an exterior surface of the metallic container is formed.

[0104] In the conventional plate exposure process, a film negative of the image 18 is created. The film negative is placed on a predetermined portion of the face portion 4 of the soft photopolymer plate 14. The soft photopolymer plate 14 with the film negative is then placed into an exposure device that exposes the soft photopolymer plate and the film negative to a light source. The film negative acts as a negative mask that blocks and prevents some of the light from reaching the face portion 4 of the soft photopolymer plate 14. The light shines through the clear sections of the film negative and hardens the material of the soft photopolymer plate 14. Exposure time to an ultraviolet light source may range from approximately 0.01 minute to approximately 10 minutes.

[0105] The material on the face portion 4 of the soft photopolymer plate 14 hardens where light passes through the film negative and strikes the face portion 4. Portions of the soft photopolymer plate 14 that are not covered by the film negative are also exposed to the light and harden. The material on the face portion of the soft photopolymer plate 14 under the areas of the film negative that block the light, or some of the light, remain unexposed and soft.

[0106] Using the CTP process, the image 18 is transferred directly to the plate in a digital imager apparatus. The digital imager apparatus ablates, or otherwise removes, portions of an opaque mask coating on the face portion 4 of the soft photopolymer plate 14 to form a negative of the image 18. The soft photopolymer plate 14 is then placed into an exposure device that exposes the soft photopolymer plate to a light source. The exposure device may be the same as, or similar to, the exposure device used in the conventional plate exposure process described above. Portions of the mask coating that were not ablated block light and prevent the light from reaching the face portion 4 of the soft photopolymer plate 14. The polymer material of the soft photopolymer plate 14 under remaining portions of the mask coating remains unexposed and soft. Light from the exposure device contacts the polymer material of the soft photopolymer plate in the image areas where the mask coating has been removed and hardens the material of the soft photopolymer plate 14. Exposure time to an ultraviolet light source may range from approximately 0.01 minute to approximately 10 minutes. An example of the CTP process is described in Advancing Flexography, The Technical Path Forward by Ray Bodwell and Jan Scharfenberg, available at http://www2.dupont.com/Packaging_Graphics/en_US/assets/downloads/pdf/AdvFlexo_Brochure.pdf, which is herein incorporated by reference in its entirety. Examples of suitable digital imager apparatus are described in Cyrel Digital flex plate Imagers (CDI), available at http://www2.dupont.com/Packaging_Graphics/en_GB/assets/downloads/pdf/CDI_family_Englis h.pdf, which is herein incorporated by reference in its entirety.

[0107] Once the image is transferred to the soft photopolymer plate 14 using either the CTP process or the conventional plate exposure process, the soft, unexposed polymer material on the face portion 4 of the exposed soft photopolymer plate 14 is removed. In one embodiment, the exposed soft photopolymer plate 14 is placed in a washing station. The unexposed, soft polymer material on unexposed areas of the face portion 4 of the soft photopolymer plate 14 is removed by washing and scrubbing the face portion 4. The washing station may include either water or a solvent, such as Cyrel Nutre-Clean. As will be appreciated, other solutions and solvents may be used in the washing station. In another embodiment, the unexposed polymer material is removed from the face portion by a post processing apparatus that does not use solvents and/or other liquids. The post processing apparatus may use thermal energy and a developer roll to remove the unexposed polymer material. After the soft, unexposed polymer material is removed, the soft photopolymer plate 14 may be exposed to light a second time to complete polymerization and ensure all areas of the plate have been hardened and to attain maximum durability.

[0108] When the unexposed soft material on areas of the face portion 4 of the soft photopolymer plate 14 have been removed, the face portion 4 will have relief areas 20 that will not receive ink and hardened areas forming images 18 that can receive ink. The image 18 formed on the soft photopolymer plate can be three dimensional and have different depths in the face portion 4 depending on the amount of light that passed through the film negative or the masking coating. The image 18, or portions of the image, have a depth of about 0.0009 inch to about 0.089 inch. In a more preferred embodiment, the depth of the image 18, or within portions of an image 18, is from approximately 0.001 inch to approximately 0.084 inch deep.

[0109] In some embodiments, the soft photopolymer plates 14 may also be etched or engraved on the face portion 4 before, during, or after the curing process to form one or more additional recessed portions. The etched or engraved areas may be formed using a laser or any other means known by those of skill in the art.

[0110] The images 18 have a maximum thickness equal to the original thickness of the soft secondary plate 14. The images 18 can be surrounded by relief areas 20. When the soft secondary plate 14 is comprised at least partially of a photopolymer material, the relief areas 20 comprise portions of the photopolymer material that were not exposed and therefore remained soft. The unexposed, soft material of the soft photopolymer plates is subsequently removed to form the relief areas 20. The size, location, and shape of the relief area formed in the soft secondary plates 14 may align with the size, location, and shape of the non-ink region 10 of the printing plate 2A illustrated in FIG. 1A and the relief area 12 of the printing plate 2B illustrated in FIG. 2A. The relief areas 20 of the soft secondary plates 14 will not accept ink from the printing plates 4 and may be used to create unique, undecorated areas (or non-inked areas) on the metallic container. The image 18 can include a relief area 20C that will not receive ink and can also include screened areas 22 that receive less ink than other portions of the image as illustrated in FIG. 4B. Although FIGS. 4A, 4B, and 4C illustrate an image surrounded by a relief area, it should be understood that an image 18 may be formed on the soft secondary plate with no relief area surrounding the image 18, as shown in FIGS. 6A and 6B. Further, it will be understood by one of skill in the art that a relief area can be of any desired size or shape and more than one relief area 20 may be formed on the soft secondary plate.

[0111] After the image 18 has been formed on the face portion 4 of the soft secondary plate 14, an adhesive transfer tape or adhesive stickyback may be added to the Mylar portion or other backing on the back portion 6 of the soft secondary plate 14. Suitable adhesive stickyback is available from a variety of commercial suppliers. In one embodiment, the adhesive stickyback is about 2.0 mil (or about 0.002 inch) thick. In another embodiment, the adhesive stickyback is about 15 mil (or about 0.015 inch) thick. The soft secondary plate 14 with the stickyback on the back portion 6 is then attached to the blanket cylinder of the decorator.

[0112] Although not illustrated in FIGS. 1-4, it will be appreciated by one of skill in the art that one or more of the printing plates 2 and/or the soft secondary plates 14 may have print registration areas that are used to monitor the registration of different colors or specialty inks printed by different plates 2, 14 to form an image on the metallic container. For example, print registration areas may be provided on the printing plates 2 and/or the soft secondary plates 14 to monitor the location and alignment of print content on metallic containers.

[0113] Referring now to FIG. 5, a decorator 24 using soft secondary plates 14 and specialty inks to form multiple images on metallic containers 34 is illustrated. The decorator 24 includes at least one plate cylinder 26. One or more printing plates 2 are attached to each of the plate cylinders 26. Additionally or alternatively, the printing plate 2 can be a sleeve or cylinder that wraps around a circumference of the plate cylinder 26. The plate cylinders 26 are operable to rotate in a first direction. Inkers 28 with rollers 30 are associated with each plate cylinder 26. The rollers 30 of each inker 28 transfer one color of ink or type of specialty ink to the ink receiving regions 8 of the printing plates 2.

[0114] As discussed herein, specialty inks include, but are not limited to, a thermochromic ink, a photochromic ink, a scented thermochromic ink, a fluorescent ink, a UV ink, a glow-in-the-dark ink, a black light ink, an infrared ink, a phosphorescent ink, a pressure sensitive ink, a tactile ink, a tactile thermochromic ink, a leuco dye, a matte ink, and any other type of ink, dye, or varnish that changes appearance, color, and/or texture in response to temperature changes or exposure to light or pressure. Specialty inks and methods of using them are disclosed in U.S. Pat. Nos. 4,889,560, 5,502,476, 5,591,255, 5,919,839, 6,139,779, 6,174,937, 6,196,675, 6,309,453, 6,494,950, 7,810,922, 8,409,698, U.S. Patent Application Publication 2012/0238675, U.S. Patent Application Publication 2013/0075675, U.S. Patent Application Publication 2013/0105743, U.S. Patent Application Publication 2013/0231242, U.S. Patent Application Publication 2012/0315412, U.S. Patent Application Publication 2013/0340885, U.S. Patent Application Publication 2014/0039091, U.S. Patent Application Publication 2014/0072442, U.S. Patent Application Publication 2014/0187668, U.S. Patent Application Publication 2014/0210201, U.S. Patent Application Publication 2014/0212654, U.S. Patent Application Publication 2014/0272161, and International Publication No. WO 2014/096088 which are each incorporated herein in their entirety by reference.

[0115] A first color of ink or type of specialty ink may be applied to the printing plates of the first plate cylinder 26A and a second color of ink or type of specialty ink may be applied to the printing plates of the second plate cylinder 26B. More colors of ink and types of specialty ink may be used if additional plate cylinders 26 are provided. In one embodiment, the decorator 24 includes from 4 to 18 plate cylinders 26 and from 4 to 18 inkers 28 each operable to apply a different color of ink or type of specialty ink to a predetermined portion of a printing plate 2. In a more preferred embodiment, the decorator includes from 6 to 18 plate cylinders and from 6 to 18 inkers each operable to apply a different color of ink or type of specialty ink to a predetermined portion of a printing plate 2.

[0116] In the example illustrated in FIG. 5, the printing plates 2 of the first plate cylinder 26A include common content, an image in the form of the words Please Recycle, in ink receiving regions 8 that will be transferred to all of the soft secondary plates 14. However, as will be appreciated by one of skill in the art, the printing plates do not have to include an image. For example, the printing plates can transfer ink to the soft secondary plates 14 without transferring an image to the soft secondary plates. The first and second plate cylinder 26A, 26B can include printing plates 2 with one or more relief areas 12 and non-ink regions 10. In one embodiment, a relief area 12 may be formed in the same location of all of the printing plates 2 except for one printing plate which does not have a relief area. The relief areas 12 formed in the printing plates 2 do not receive ink from the inkers 28 and will not transfer ink to the secondary plates 14. The one printing plate 2 without a relief area will transfer ink to all images 18 and ink receiving regions 16 of the soft secondary plates 14 that contact the ink receiving regions 8 of the face portion 4 of the one printing plate 2 without a relief area. Additionally or alternatively, one or more printing plates 2 can transfer different colors of ink and types of specialty ink to the same location of the soft secondary plates 14. Thus, different colors of ink and types of specialty ink may be transferred from one or more printing plates 2 to the same location of the soft secondary plates 14 in overlapping layers.

[0117] The decorator 24 also includes a blanket cylinder 32 to which one or more soft secondary plates 14 are attached. Additionally or alternatively, the one or more soft secondary plates 14 can be a sleeve or cylinder of a soft photopolymer material or a sleeve of rubber that wraps around the circumference of the blanket cylinder 32. The blanket cylinder 32 rotates in a second direction opposite to the first direction of the plate cylinder 26. Each soft secondary plate 14 may have a different image 18 formed thereon. For example, the soft secondary plates 14 illustrated in FIG. 5 include an image 18B of a sports jersey, an image 18C of a star, an image 18D of an X, and an image 18E of a lightning bolt formed thereon. The images 18 on the soft secondary plates 14 can be formed in locations corresponding to, or aligning with, the relief areas 12 of the printing plates 2. The images 18 of the soft secondary plates 18 may be negatives (formed by relief areas 20 that will not receive ink) that leave non-inked areas on the decorated metallic container 34, or the images 18 may be positives that will receive ink when the images 18 contact one or more ink receiving regions 8 of the printing plates 2 that have received ink from an inker 28. For a soft secondary plate 14 formed at least partially of a photopolymer material, a positive portion of an image is formed by exposed, hardened areas of the soft photopolymer plates 14. The positive portions of an image formed on a soft secondary plate 14 formed at least partially of rubber comprise the portions of the face 4 of a soft secondary plate 14 that are not removed during the image forming process or areas adapted to attract ink. The images 18 can also include combinations of negative and positive areas. It will be understood by those of skill in the art that a positive image will apply ink to a metallic container and a negative image means an absence of ink in a printed or positive part of an image.

[0118] The plate cylinders 26 rotate in the first direction and the blanket cylinder 32 rotates in the second opposite direction in unison to bring the printing plates 2 into contact with the soft secondary plates 14. Ink is transferred to the ink receiving regions 16 and images 18 of the soft secondary plates 14 that contact the inked ink receiving regions 8 of the printing plates 2. The main image exposure occurs on the inked printing plates 2 and a secondary image is produced by the soft secondary plates 14. The soft secondary plates 14 may have ink receiving regions 16 that are common for all of the soft secondary plates 14. The areas where images 18 are formed on the soft secondary plates, such as the images 18A, 18B illustrated in FIGS. 4A and 4B, will create unique inked areas for each soft secondary plate 14. The process is similar to a stamp ink pad and rubber stamp where only the raised portion of the rubber stamp collects ink from the ink pad and transfers the ink to a substrate as an image. Relief areas 20 of the soft secondary plates 14 will not receive ink from the printing plates 2. Only the images 18 or the ink receiving regions 16 of the soft secondary plates 14 will receive ink from the printing plates 2 and transfer the ink onto the surface of the metallic containers. By using soft secondary plates 14 with different images 18 formed thereon a completely different image will be printed on each metallic container. This results in multiple lithographic images being produced from a single set of printing plates 2 on the plate cylinders 26 of the decorator 24. The process uses high-definition solid and screened images formed on the soft secondary plates 14 resulting in unique ink transfer to metallic containers.

[0119] In operation, a metallic container 34 is fed to a support cylinder 38 by a conveyor 36 or other means from a storage location or facility 42. The support cylinder 38 has a plurality of stations 40 adapted to receive and hold a metallic container 34 in a predetermined position aligned with the soft secondary plates 14. The stations 40 can hold the metallic containers 34 in a stationary position and can also rotate the metallic containers 34 about each container's longitudinal axis. As the blanket cylinder 32 rotates in the second direction, the support cylinder 38 rotates in unison in the first direction to bring an exterior surface 44 of the metallic container 34 into rotational contact with an inked soft secondary plate 14 attached to the blanket cylinder 32. The ink is then transferred from the soft secondary plate 14 to the exterior surface 42 of the metallic container 34. Although a support cylinder 38 is illustrated in FIG. 5, it should be understood that other means of supporting the metallic containers 34 and bringing the exterior surface 44 of them into contact with the soft secondary plates 14 may be used, such as a mandrel wheel or a conveyor belt. After the ink is transferred to the metallic container 34, a varnish unit 48 may optionally apply an over varnish to the metallic container 34. The over varnish may comprise a specialty ink. If necessary, the ink and/or the over varnish may be cured by a curing unit 50 by any method known to those of skill in the art. In one embodiment, the curing unit 50 may use one or more of thermal energy, ultraviolet energy, and an electron beam to cure the ink and/or the over varnish on the metallic container 34.

[0120] Two decorated metallic containers 34A, 34B are also illustrated in FIG. 5. The decorated metallic containers include an image of common content (Please Recycle) which is transferred from the printing plate 2C. Container 34A includes unique content, the image 18B of a sports jersey, and container 34B includes a unique image 18C of a star.

[0121] Decorators 24 used in the commercial metallic container industry generally have blanket cylinders 32 with between about 4 to 12 individual soft secondary plates 14 attached. When each of the 4 to 12 individual soft secondary plates 14 has a unique image 18 formed thereon, the decorator 24 can produce from 4 to 12 different lithographic images without changing the printing plates 2. The present invention will work with a blanket cylinder 32 with any number of soft secondary plates 14 attached to its circumference. In addition, although the soft secondary plates 14 are illustrated in FIG. 5 as individual secondary plates, in some embodiments the blanket cylinder 32 may have one continuous blanket of a photopolymer material or rubber affixed to its circumference, the continuous blanket having multiple unique images formed thereon. In another embodiment, one or more soft secondary plates comprised at least partially of rubber and one or more soft secondary plates comprised at least partially of a photopolymer material may be attached to the blanket cylinder 32 at the same time. Each of the rubber soft secondary plates or the soft photopolymer plates may have one or more different images 18 formed thereon. In another embodiment, printing plates 2 formed of rubber or a soft photopolymer material may be attached to one or more of the plate cylinders 26. Each of the rubber printing plates or the photopolymer printing plates may have one or more ink receiving regions 8, non-ink regions 10, and relief areas 12 that form an image.

[0122] Referring now to FIG. 6A, a photograph of a soft secondary plate 14F comprised of a photopolymer material is provided. The soft secondary plate 14F includes an image 18 of a sports jersey with the number 92 formed thereon according to various embodiments of the present invention. FIG. 6B is an enlarged photograph of the image 18 of FIG. 6A. In the embodiment illustrated in FIGS. 6A and 6B, the image 18 is not surrounded by a relief area.

[0123] Referring now to FIG. 7A, a photograph of a generally cylindrical metallic container 34F decorated according to various embodiments of the present invention with the soft secondary plate 14F shown in FIG. 6A is provided. FIG. 7B is an enlarged portion of the photograph of FIG. 7A. The photographs show a generally cylindrical metallic container 34F decorated with a sports jersey which includes the number 92 formed in a non-inked portion 46 (or negative) of the decoration. Other numbers, shapes, words, or designs could be formed to decorate a substrate using the present invention.

[0124] Referring now to FIG. 8, a photograph of another soft secondary plate 14G with several images formed thereon according to various embodiments of the present invention is provided. The soft secondary plate 14G is comprised of a photopolymer material. A photograph of a generally cylindrical metallic container 34G decorated according to various embodiments of the present invention using the soft secondary plate 14G of FIG. 8 is shown in FIG. 9. FIGS. 10A and 10B provide enlarged photographs of a first image and a second image formed on the metallic container 34G shown in FIG. 9.

[0125] The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limiting of the invention to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments described and shown in the figures were chosen and described in order to best explain the principles of the invention, the practical application, and to enable those of ordinary skill in the art to understand the invention.

[0126] While various embodiments of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention, as set forth in the following claims. Further, the invention(s) described herein is capable of other embodiments and of being practiced or of being carried out in various ways. In addition, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of including, comprising, or having and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.