Method and apparatus for printing metallic beverage container bodies

Abstract

A pair of metallic beverage container bodies is sequentially decorated in a direct single file queue by a dry offset rotary metallic beverage container decorator. A container body has a common design element, a first unique design element in a first color, and a second unique design element in a second color on its outer surface. The first unique design element is located within a boundary of the second unique design element. A second container body has the common design element, a third unique design element in the first color, and a fourth unique design element in the second color on the outer surface. The third unique design element is unique relative to the first and second design elements. The third unique design element is located within a boundary of the fourth unique design element.

Claims

1. A method of consecutively decorating a plurality of substantially identical metallic beverage container bodies using a dry offset decorating apparatus without manufacturing interruption wherein each of the metallic beverage container bodies has an open end separated from a closed end by a circumferential side wall, the method comprising the steps of: providing a first image transfer blanket comprising: a first ink receiving surface having a first unique design element in high relief relative to directly adjacent portions of the first ink receiving surface bordering the first unique design element and a second unique design element in low relief within the first ink receiving surface, the first ink receiving surface having a length greater than or equal to a circumferential length of a first metallic beverage container body plus a length of an arc of the first metallic beverage container body subtending an angle of 15?; providing a second image transfer blanket comprising: a second ink receiving surface having a third unique design element in high relief relative to directly adjacent portions of the second ink receiving surface bordering the third unique design element and a fourth unique design element in low relief within the second ink receiving surface, wherein the third unique design element is unique relative to the first design element on the first image transfer blanket, the second ink receiving surface having a length greater than or equal to a circumferential length of a second metallic beverage container body plus a length of an arc of the second metallic beverage container body subtending an angle of 15?; sequentially indexing each of the plurality of substantially identical metallic beverage container bodies to a printing site on the dry offset decorating apparatus; engaging a circumferential side wall of the first metallic beverage container body with the first ink receiving surface of the first image transfer blanket and rotating the first metallic beverage container body circumferential side wall at least 6.6 radians while engaged with the first ink receiving surface and along a length of the first ink receiving surface greater than a circumferential length of the first metallic beverage container body circumferential side wall; and engaging a circumferential side wall of the second metallic beverage container body with the second ink receiving surface of the second image transfer blanket and rotating the second metallic beverage container body circumferential side wall at least 6.6 radians while engaged with the second ink receiving surface and along a length of the second ink receiving surface greater than a circumferential length of the second metallic beverage container body circumferential side wall.

2. The method of claim 1 wherein the first metallic beverage container body has a resultant decoration that is unique relative to a resultant decoration exhibited by the second metallic beverage container body subsequent to the two engaging and rotating steps.

3. The method of claim 2 wherein the rotating of the first and second metallic beverage container bodies for at least 6.6 rad is carried out while the first and second metallic beverage container bodies are engaged with ink-bearing portions of the first and second ink receiving surfaces, respectively.

4. The method of claim 3 wherein the first unique design element is spaced from the second design element on the first ink receiving surface such that rotation of the first metallic beverage container circumferential side wall by at least 6.2 radians against and along a length of the first ink receiving surface causes a first ink pattern associated with the first unique design element to be deposited on the first metallic beverage container side wall and causes a second ink pattern associated with the second unique design element to be deposited on the first metallic beverage container side wall and wherein the first ink pattern and the second ink pattern overlap.

5. The method of claim 4 wherein the third unique design element is spaced from the fourth design element on the second ink receiving surface such that rotation of the second metallic beverage container circumferential side wall by at least 6.2 radians against and along a length of the second ink receiving surface causes a third ink pattern associated with the third unique design element to be deposited on the second metallic beverage container side wall and causes a fourth ink pattern associated with the fourth unique design element deposited on the second metallic beverage container side wall and the third ink pattern and the fourth ink pattern overlap.

6. The method of claim 5 wherein the second and fourth ink patterns are defined by a surface area of the first image transfer blanket and the second image transfer blanket, respectively, having an absence of ink bounded by an identical common design element on each of the first image transfer blanket and the second image transfer blanket.

7. The method of claim 5 wherein the first and second image transfer blankets have an identical common design element on the first and second ink receiving surfaces, respectively, and which forms a boundary around the second and fourth unique design elements in low relief, respectively.

8. The method of claim 7 further comprising the steps of: providing a plurality of ink applicators each supplied with a different color of ink; providing a plurality of printing plates wherein each printing plate has a print surface in high relief; engaging each of the plurality of ink applicators with a corresponding printing plate and transferring a quantity of ink thereto; engaging each of the plurality of printing plates with the first ink receiving surface of the first image transfer blanket to provide a common ink pattern associated with the identical common design element and to provide ink to the first unique design element in high relief prior to the engaging a circumferential side wall of a first metallic beverage container body with the first ink receiving surface of the first image transfer blanket step; repeating the engaging each of the plurality of ink applicators to each of the plurality of printing plates step; and engaging each of the plurality of printing plates with the second ink receiving surface of the second image transfer blanket to provide a common ink pattern associated with the identical common design element and to provide ink to the third unique design element in high relief prior to the engaging a circumferential side wall of a second metallic beverage container body with the second ink receiving surface of the second image transfer blanket step.

9. The method of claim 8 wherein the first and third ink patterns are defined by first and third ink pattern surface areas, respectively, and the second and fourth ink patterns are defined by second and fourth ink pattern areas, respectively, wherein the first and third ink pattern surface areas are located completely within boundaries of the second and fourth ink pattern surface areas, respectively.

10. The method of claim 8 wherein the first and third ink patterns are defined by first and third ink pattern surface areas, respectively, and the second and fourth ink patterns are defined by second and fourth ink pattern areas, respectively, and wherein the first and third ink pattern surface areas are less the second and fourth ink pattern surface areas, respectively.

11. The method of claim 8 wherein the first and third ink patterns are defined by first and third ink pattern surface areas, respectively, and the second and fourth ink patterns are defined by second and fourth ink patterns, respectively, and wherein the first and third ink pattern surface areas are greater than the second and fourth ink pattern surface areas, respectively.

12. The method according to claim 1 wherein the first and third unique design elements are alphanumeric characters.

13. The method according to claim 1 wherein the second and fourth unique design elements are alphanumeric characters.

14. The method according to claim 1 wherein the first unique design element is a same alphanumeric character as the second unique design element.

15. The method according to claim 1 wherein the third unique design element is a same alphanumeric character as the fourth unique design element.

16. A method comprising: consecutively decorating a plurality of substantially identical metallic beverage container bodies using a dry offset decorating apparatus without manufacturing interruption wherein each of the metallic beverage container bodies has an open end separated from a closed end by a circumferential side wall by over-rotating first and second metallic beverage container bodies 6.6 radians against lengths of first and second ink receiving surfaces on first and second image transfer blankets, respectively, which are greater than circumferential lengths of each of the metallic beverage container bodies, wherein a first metallic beverage container body first engages an ink-bearing leading edge of a first unique design element in high relief and wherein a first edge of the first unique design element is separated from a first edge of a common design element on the first ink receiving surface by a low relief portion of the first ink receiving surface and wherein the first metallic beverage container body further engages an ink-bearing portion of the first ink receiving surface comprising the common design element thereon, and wherein a second unique design element on the first ink receiving surface is in low relief between the first edge of the common design element and the first edge of the unique design element, wherein a first art associated with the first unique design element overlies a second art associated with the second design element and the first art is located completely within a surface area of the second art.

17. The method of claim 8 wherein the first and third ink patterns are defined by first and third ink pattern surface areas, respectively, and the second and fourth ink patterns are defined by second and fourth ink pattern areas, respectively, and wherein the first and third ink pattern surface areas are substantially equal to the second and fourth ink pattern surface areas, respectively.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings in which:

(2) FIG. 1 is a view of the printing apparatus of the prior art;

(3) FIG. 2 is a schematic view of a pallet compared with a man of medium height;

(4) FIG. 3 is a perspective view of the printing apparatus of the present invention;

(5) FIG. 4 is a perspective view of internal details of the printing apparatus of the present invention;

(6) FIG. 5 is an enlarged perspective view of internal details of the printing apparatus of the present invention;

(7) FIG. 6 is an enlarged perspective view of internal details of the printing apparatus of the present invention;

(8) FIG. 7 is a perspective view of a set of transfer blankets;

(9) FIG. 8 is a perspective view of a set of printed cans according to the present invention;

(10) FIGS. 9-16 are alternate versions of FIGS. 1-8, respectively;

(11) FIG. 17 is a top and cross-sectional view of a transfer blanket showing zones A, B, and C;

(12) FIG. 18 is a magnified view of zone A from FIG. 17;

(13) FIG. 19 is a magnified view of zone A from FIG. 17;

(14) FIG. 20 is a magnified view of zone A from FIG. 17;

(15) FIG. 21 is a magnified view of zone B from FIG. 17;

(16) FIG. 22 is a magnified view of zone B from FIG. 17;

(17) FIG. 23 is a magnified view of zone B from FIG. 17;

(18) FIG. 24 is a photograph of three sequentially produced cans according to the principles of the present invention; and

(19) FIGS. 25A-D are front views of blankets of the present invention; and

(20) FIG. 26 is a perspective view of an inked printing plate affixed to a plate cylinder wherein substantially an entirety of the inked surface of the printing plate is in high relief;

(21) FIG. 27A is a side view of a metallic beverage container body rotating and traversing an image transfer blanket;

(22) FIG. 27A is a side view of a metallic beverage container body rotating and traversing an image transfer blanket;

(23) FIG. 27B is an alternative side view of a metallic beverage container body rotating and traversing an image transfer blanket with an over-rotation of about 15?;

(24) FIGS. 28-30 are side views illustrating a metallic beverage container body rotating and traversing an image transfer blanket;

(25) FIG. 31 is a top view of an image transfer blanket having ink applied thereto;

(26) FIG. 32 is a cross-section of an image transfer blanket of FIG. 31;

(27) FIG. 33 is a perspective view of an image transfer blanket;

(28) FIG. 34 is a top view of an image transfer blanket having ink applied thereto;

(29) FIG. 35 is a cross-section of the image transfer blanket of FIG. 34;

(30) FIGS. 36 and 37 are side views of consecutively produced and decorated metallic beverage container bodies using image transfer blankets made according to the principles of FIGS. 31 and 34, respectively;

(31) FIG. 38 is a top view of an alternative form of an image transfer blanket having ink applied thereto;

(32) FIG. 39 is a top view of an alternative form of an image transfer blanket having ink applied thereto;

(33) FIGS. 40 and 41 are side views of consecutively produced and decorated metallic beverage container bodies using image transfer blankets made according to the principles of FIGS. 38 and 39, respectively;

(34) FIG. 42 is a top view of an alternative form of an image transfer blanket having ink applied thereto;

(35) FIG. 43 is a top view of an alternative form of an image transfer blanket having ink applied thereto;

(36) FIGS. 44 and 45 are side views of consecutively produced and decorated metallic beverage container bodies using image transfer blankets made according to the principles of FIGS. 42 and 43, respectively;

(37) FIG. 46 is a top view of a printing plate with ink thereon;

(38) FIG. 47 is a cross-section view of the printing plate of FIG. 46;

(39) FIG. 48 is a side view of the printing plate of FIG. 46 face-to-face with an image transfer blanket of the present invention;

(40) FIG. 49 is a side view of a printing plate in an engagement with an image transfer blanket and transferring ink thereto;

(41) FIG. 50 is a top view of an image transfer blanket having ink applied thereto;

(42) FIG. 51 is a cross-section of an image transfer blanket of FIG. 50;

(43) FIG. 52 is a perspective view of an image transfer blanket;

(44) FIG. 53 is a top view of an image transfer blanket having ink applied thereto;

(45) FIG. 54 is a cross-section of the image transfer blanket of FIG. 53; and

(46) FIGS. 55 and 56 are side views of consecutively produced and decorated metallic beverage container bodies using image transfer blankets made according to the principles of FIGS. 50 and 53, respectively.

DETAILED DESCRIPTION

(47) While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.

(48) The object of FIG. 1 was described above in the explanation of the prior art. However, it is important to stress that the invention in question is applied to a can printer, that is, a printing apparatus 1. The invention also relates to a modification introduced in such equipment, which enables one to print different finished arts onto cans, this printing takes place without interruption of the production.

(49) The printing apparatus 1 can be observed in greater detail in FIG. 3, which shows a can chain 7 having a plurality of cans 8 that are fixed to said can chain 7 in a rotatory manner. In the left portion of this FIG. 3, one can see cans 8 that come from the initial production processes, mainly from the mechanical shaping processes. These cans pass through a first directing wheel 9 and then through a second directing wheel 10. In this way, and with the aid of other elements of the equipment, not described or disclosed, it is possible to direct the cans 8 retained in the can chain 7 so that they will be led to the can carrying apparatus or can indexer 11.

(50) On the can indexer 11, the cans are then displaced in a circle around said indexer 11. Although the cans 8 are retained in the can chain 7, they still have the possibility of turning around their main axis, i.e. a central longitudinal axis about which the can is formed.

(51) In the right portion of FIG. 3, one can see eight ink-cartridges 2a-2h, positioned in half-moon arrangement, which follow the same central axle 12. It can be noted that, in this embodiment of the invention, there is a limited number of ink-holders, but it is important to point out that this is a project option, and there may be a larger or smaller number of ink-cartridges 2.

(52) In FIG. 4, which shows the right portion of FIG. 3, one can see in greater detail the inside of the printing apparatus 1. The central axle 12 is, indeed, the transfer blanket drum 6, which has a radial arrangement of the ink-cartridges 2a-2h close to part of its perimeter.

(53) However, the ink-cartridges 2a-2h do not rest on the transfer blanket drum 6, since between each ink cartridge 2a-2h and the transfer blanket drum 6 there are respective plate cylinders 4a-4h. As mentioned above, on the plate cylinders 4a-4h there are respective printing plates 3a-3h that have the finished arts in relief on their outer surface facing the transfer blanket drum 6.

(54) Moreover, the printing plates 3a-3h are responsible for the communication between the ink-cartridges 2a-2h and the transfer blankets 5a-5l, which are placed on the outer surface of the transfer blanket drum 6. Obviously, there should be a positioning/interaction between the printing plates 3a-3h and the transfer blankets 5a-5l, so that the transfer blankets 5a-5l can interact in a precise manner with the cans 8 to be printed.

(55) With a view to exemplify how the interaction between the components responsible for the printing takes place, FIG. 5 shows an internal portion of the printing apparatus 1. For practical purposes, one will demonstrate only the functioning of a part of the transfer of ink for printing, since the process is analogous for each ink-cartridge.

(56) In FIGS. 5 and 6, the process, also an object of the present application, can be better understood, wherein the ink cartridge 2a supplies ink to the printing plate 3a present on the plate cylinder 4a, and ink is transferred chiefly to the high reliefs existing there, which have a finished art or print arrangement.

(57) The plate cylinder 4a, upon coming into synchronized contact by the printing plate 3a with the transfer blankets drum 6, supplies ink from its high relief to the transfer blanket 5a, wherein this takes place by rotation of the printing plate that transfers the ink present on high relief to the transfer blanket 5a.

(58) Afterwards and by opposite directions rotation of the transfer blanket drum 6 and the can indexer 11, the transfer blanket 5a that has the ink from the printing plate 3a transfers the ink present on the transfer blanket 5a to the can 8, which is rotated under some pressure against the transfer blanket 5a.

(59) It is pointed out that, if it is necessary to print more than one finished art or different colors onto the can 8, the transfer blanket 5a will also have passed through the other printing plates 3b-3h present on the respective plate cylinders 4b-4h. The same occurs successively with the other transfer blankets 5b-5l that have the finished art coming from any printing plates that are necessary for obtaining all the finished art of different colors on the cans 8 to be printed.

(60) Thus, the finished arts present on the printing plates are transferred to the transfer blankets, which in turn transfer ink to the cans 8.

(61) The transfer blankets of the present invention can be seen in FIG. 7.

(62) Usually, that is, in the prior art, these transfer blankets are only smooth surfaces that are used as ink transferring means between the printing plates 3a-3h and the cans 8 to be printed. However, in the present invention the transfer blankets also have the function of being a graphics mean that has influence on the finished arts of the cans 8 to be printed.

(63) In the example of FIG. 7, one demonstrates only three transfer blankets 5a-5c, but there may be several blankets with low relief according to the need for different finished arts on the cans 8. In other words, the number of different finished art or graphs from the blankets on the cans is limited to the number of blankets present on the blanket drum 6.

(64) In the preferred embodiment of the present invention one has opted for using a transfer blanket drum with twelve blankets 5a-5l, but, as mentioned before, only three blankets are shown in FIG. 7.

(65) It is of the utmost importance to note that the transfer blankets 5a-5c have respective low reliefs 13a-13c, wherein the low reliefs of finished arts are in reality low relief 13a-13c with different shapes. Therefore, there is a finished art in low relief 13a present on the blanket 5a, a finished art in low relief 13b present on the blanket 5b and another finished art in low relief 13c present on the blanket 5c.

(66) Thus, when there are three types of blankets 5a-5c with different finished arts in low relief, it is possible that all the finished arts coming from printing plates will be transferred by ink to the transfer blankets 5a-5c, so that the cans 6 will be printed in this way.

(67) However, since each of the finished arts 13a-13c is in low relief, there will be no ink in this low-relief portion of each of the blankets. There will be no contact, in this low-relief region, between the blanket and the cans 8 to be printed. Indeed, the original color of the can 8 will remain in this region free from ink or free from contact between the can 8 and the respective blanket that is transferring the ink from the transferring blankets to the can 8.

(68) Therefore, if there is a low-relief finished art 13a on the blanket 5a which, in the present example, a circle, there will be no print or ink transfer from this low-relief region to the can 8. Therefore, a first finished art is formed on the can 8, as shown in FIG. 8, which is in the form of a circle, for explanation purposes.

(69) Thus, the next can 8 to be printed will also receive ink from the printing plates, but from the next blanket. In this example, the transfer blanket 5a has a low-relief finished art 13b in the form of a rectangle. In this way, the can to be printed will have a second finished art in the form of a rectangle in the original color of the can.

(70) Following the same logic, a third can to be printed will also receive ink from the printing plates, but from a subsequent blanket other than the first two ones. This third transfer blanket 5c has a low-relief finished art 13c in the form of a pentagon, so that the can to be printed will have a third finished art in the form of a pentagon in the original color of the can.

(71) As already mentioned, the number of different finished art on the cans will only be limited to the number of blankets present on the blanket drum 6.

(72) It is further stressed that the finished arts present on the blanketsthat are portions of removed material of the blanketsare arranged directly on the blankets without any other type of layer on the blanket, so that the latter can have the printing function, i.e., the function of having a finished art that will be present on the printed can.

(73) It is reiterated that the low reliefs or portions of material removal will represent absence of ink, which will enable one to view the original color of the can, be it the color of the aluminum or of a coating of other coloring that the can to be printed already has.

(74) The finished art produced by the low relief will be a final contour on the printed can, which will provide a clearer finished art, and the low relief present on the blanket will have less problems with usual printing aspects, such as, for instance, ink stains, smears or any other type of problem related to the high-precision printing or detailing.

(75) In FIG. 8, one demonstrates by reticence that there is the possibility of more than three types of finished arts from the printing process and apparatus of the present invention. This is verified through a subsequent can with another finished art in the form of three consecutive lines.

(76) Obviously, the finished arts or graphic arrangements are not limited to geometric shapes, but may be any type of graphic means that one desires to print on the cans 8, as for example, names of persons, of teams, figures, etc. In this regard, the limitation is no longer in the printing process, but rather in the creativity of those who develop the finished arts to be applied to the printed cans.

(77) In the face of the foregoing, it is possible to have, in the same uninterrupted production line, cans with different finished arts, which was possible only with the interruption of the production line until the advent of the present invention.

(78) However, it was not feasible, in terms of logistics, to obtain cans from the same production sequence with different finished arts on the same pallet, or still delivered to the beverage manufacturers, such as supermarkets. However, this has become possible with the present invention.

(79) According to another embodiment of the present invention, artwork with improved resolution and/or increasing complexity can be generated using transfer blankets 5a-5l with improved, highly detailed low-relief features. In the prior art, the printing plates 3a-3h carry detailed art in high relief as described above. The high relief art is transferred to a transfer blanket 5a-5l which then prints the can 8. As described above, the transfer blankets 5a-5l may be supplied with low relief art wherein the can 8 will have an area devoid of ink corresponding to the low relief art on the transfer blankets 5a-5l. By way of example, under a prior art printing process, printing plate 3a-3h will have a relief feature. To print, for example, BRAND X SODA on a can, a printing plate 3a-3h has BRAND X SODA in high relief a surface of the printing plate 3a-3h. Then the ink is applied to the high relief on the surface of the printing plate in the shape of BRAND X SODA.

(80) In the present invention, it is contemplated that improved and more flexible high resolution low-relief features can be generated by treating the transfer blankets 5a-5l with a suitable laser beam. In this embodiment, portions of the blanket 5a-5l are removed by laser treatment. Through laser ablation, very different, highly complex and detailed relief patterns can be created on each of the transfer blankets 5a-5l, rather than simple shapes and the like as discussed above.

(81) For example, each blanket 5a-5l is typically produced from a non-metallic material such as a rubber (or a polymer or composite) rectangle the size of a legal paper. Each blanket is typically ? to ? inch thick (3.2 mm to 6.4 mm). Shading can be generated by varying the depth and size of the low-relief features. In practice, printed areas on a finished can be made lighter or darker depending on how much of the surface of a particular transfer blanket 5a-5l is removed during the laser treatment process.

(82) Basically, there are two different properties that are essential to the laser treatment discussed herein: tolerance of the cut and surface finish. Standard technology laser cutting equipment that has been in use for 5+ years uses a focused laser beam. The spot size of the laser beam determines the tolerance and the surface finish. Older laser cutting machines that have been in service for 5+ years, have 0.008 to 0.010 inches spot diameter size (0.2 mm to 0.3 mm). Newer laser cutting machines a focus within a spot diameter size of 1-2 thousandths (0.001 to 0.002 inches) of an inch (0.03 mm to 0.05 mm). Generally, using a laser as contemplated by the inventors, a low-relief feature having a surface finish or depth as little as 0.001 inches (0.03 mm) or less can be created.

(83) In creating high resolution low-relief features on a transfer blanket 5a-5l using a laser cutting apparatus, the apparatus must position and move the beam accurately. Because the beam is moving in two dimensions (e.g., an X & Y coordinate system) speed of the laser beam movement must be controlled. For example, if a straight cut is being generated, the laser beam speed across the surface of the transfer blanket needs to be constant. Once a curved cut or low-relief pattern is desired, the speed at which the laser beam travels must be varied so that the laser beam can affect the cut itself. Software and algorithms calculate the proper speed of the laser beam along the surface as cuts are made. Suitable transfer blankets have been manufactured using a 420 W Stork? brand laser engraver set at a speed of about 12 m/s The result is a smooth cut and a smooth surface finish.

(84) To avoid a resultant blurring effect on a finished can caused by the low-relief features produced by laser ablation on the transfer blankets 5a-5l, the surface of the transfer blanket 5a-5l must have a better surface finish, especially, or primarily, an edge of the transfer blanket surface between the low-relief laser ablated surface and an untreated surface. The better the edge surface the laser creates, the better the printed edge of the finished product. This better surface finish will result in a cleaner, crisper image.

(85) Final surface finish of a laser treated transfer blanket 5a-5l is dependent on the transfer blanket 5a-5l thickness prior to laser treatment. A thicker transfer blanket will have a rougher final surface finish. The laser does not cut as smoothly in thicker substrates.

(86) However, depending on the algorithm, the speed, and the arc, smoothness of the laser cut can be improved. When a laser is cutting an arc or intricate shapes, the algorithm will change the speed and how the laser beam is moving. This results in a cleaner shape.

(87) In generating transfer blankets of the present invention laser beam spot size was generally on the order of 0.003 inches (0.08 mm). However, such a spot size is inadequate for producing cans with high resolution graphics devoid of ink as contemplated herein. More specifically, the inventors determined that transfer blanket low-relief pattern quality suffers when a laser beam spot size greater than 0.002 inches (0.05 mm) is employed. This will result in a target surface finish of about 125 to 250 micro inches (about 0.002 inches or 0.05 mm).

(88) To illustrate this aspect of the invention, referring to FIGS. 17-23, a transfer blanket 5 is treated with a laser to produce a low-relief rectangle 50. A zone A of FIG. 17 represents a corner 54 of the rectangle on an upper surface of the blanket 5 forming an edge between a laser treated portion of the blanket 5 and an untreated portion of the blanket 5; a zone B represents inside corners 66,68 of the rectangle 50; and a zone C represents a laser treated surface finish upon the rectangle floor.

(89) Referring to FIGS. 18-20, in zone A, the corner 54 quality is a function the laser beam design, accuracy of the XY coordinate axis positioning, and the blanket 5 material. As shown in FIG. 18, a sharp 90? corner is difficult to achieve. Generally, the corner exhibits a certain radius of curvature as shown in FIG. 19. Regarding the edge level quality in FIG. 19, the edge quality of the corner 54 is material dependent because projection of the blanket material may take place during laser treatment. Thus, the contour of the cut must be within 2 parallel lines as shown in FIG. 20.

(90) Referring to FIG. 21, in theory, in zone B, sharp angles at the inside corners 66,68 would result from laser ablation forming the rectangle 50. However, as shown in FIG. 22, due to the laser milling process, there will be 2 separate curvatures at the corners 66,68, a first radius of curvature on the edge of the corner 66 forming the contour of the rectangle and a second radius of curvature at the corner 68 forming a bottom of the ablated groove. These radii are specific to the laser process used (laser type, laser parameters, material type). As shown in FIG. 23, a wall 70 between the corners 66,68 is angled between 75? and 105?, typically angled outwardly greater than 90?, more specifically 105??5?. In practice, substantially 90? angles are formed at the corners when forming a solid image, such as the rectangle 50 shown. When producing micro portions or dots as described below, the wall 70 will generally be angled according to the parameters set forth above.

(91) Further, the corner 66 forming the contour of the rectangle is critical in establishing the high level of graphic quality discussed hereinafter. A surface finish of the transition between an upper surface of a blanket 5 on which ink is deposited by a printing plate 3 (high relief portion) and the recessed portion of the blanket 5 (low relief portion) is less than or equal to 3.5 R.sub.a, preferably less than 3.5 R.sub.a, and more preferably 3.0 R.sub.a?0.1 R.sub.a. Additionally, the most preferable surface finish in this region has 3.33 R.sub.max. Adequate blankets have been manufactured having a surface finish of about 3.03 R.sub.a.

(92) In zone C, the rectangle floor's surface finish is a function of laser technology and blanket material. A target of 125 to 250 micro inches (about 0.002 inches or 0.05 mm) for the surface finish is preferred to achieve desired results. Suitable blankets having a surface roughness of 3.03 R.sub.a (3.33 R.sub.max) have been produced having a floor depth of about 0.015 inches (0.38 mm). It has been determined that the floor depth of about 0.015 inches (0.38 mm) performs well in that ink is not transferred from the low relief floor to the beverage container 8 when the floor is at least 0.015 inches (0.38 mm).

(93) FIG. 24 shows an example of three sequentially produced, i.e. directly consecutive without manufacturing interruption, beverage containers which may be produced having highly detailed unique art, relative to each other. These cans have gray scale art produced with three unique blankets 5a-5c according to the present invention. Note that much of the detail is achieved by way of the natural metallic color of the metallic can produced by low relief features on the blankets 5a-c. In this example, at least one of the printing plates has a relatively large portion of the upper surface in high relief. If the blankets 5a-c were typical blankets used in the art, the cans would have no art other in an area of the can sidewall corresponding to the high relief portion of the printing plate other than an overall black color. In other words, but for the relief art on the blankets 5a-5c, the cans would at least have a very large black portion. However, when blankets 5a-5c according to the present invention are employed having low relief features, the cans exhibit art in a color combination comprising the background color (black) and highly detailed unique art formed by the original color of the can. This is accomplished by the printing plate having substantially a large area of an upper surface in high relief with ink deposited thereon which delivers the ink to high relief portions of the blanket (black). The blanket has highly detailed unique art laser etched thereon in low relief. The beverage container can otherwise have art detail provided by the remaining printing plates. In other words, each metal beverage container produced in sequence up to a finite number of metal beverage containers, typically less than fifteen, will have a first art identical to the other metal beverage containers in the sequence and a second art unique to the individual metal beverage container.

(94) Even more detailed metal beverage container decoration and images can be created by using an interplay between the high and low relief features on the printing plates 3 with the high and low relief features on the transfer blankets 5 together with the colors delivered from the ink cartridges 2. See, for example, FIG. 24.

(95) FIGS. 25A-D are front views of blanket 5a-5d of the present invention which illustrate how low relief features produced according to the methods described above can be used to generate highly detailed art when used in combination with printing plates as described above. Here, low relief features can be varied in size and location to produce shading and detail which results in a very complex image. According to further principles of the invention, a plurality of unique blankets can be introduced into a rotary inking apparatus as described above wherein a corresponding plurality of different resultant cans can be produced continuously and sequentially. For example, in the blanket illustrated, a man's face is depicted. In practice, the can printing apparatus may be outfitted with a plurality of blankets 5a-5d, e.g. four, wherein each exhibit unique low relief features, relative to each other, to produce 4 cans sequentially, wherein each of the four cans has a different art thereon, for instance four different men's faces in the example illustrated. It should be noted that the number of different sequentially produced cans is only limited by the number of blankets a particular printing apparatus is capable of using. In the previous example, as few as two and as many as twenty-four different sequentially produced cans may be produced continuously.

(96) More particularly to FIGS. 25A-D, each blanket 5a-5d has been treated with a laser to remove portions of an upper surface 84 of each blanket 5a-5d. Using a laser having a laser beam spot size less than 0.002 inches (0.05 mm) very precise removal of the blanket material can produce micro high relief and low relief portions 88,92 of the upper surface 84 of the blankets 5a-5d. A black ink has been applied to the upper surface 84 of the blankets 5a-5d. It follows that the high relief features 88 are black in the figures, and the low relief features 92 are a lighter color. The resultant sequentially and continuously printed cans have unique art heretofore unrealized in the can making art.

(97) Consecutively Manufactured Metallic Beverage Container Bodies

(98) Using the principles described above and the further principles yet to be described, a plurality of metallic beverage container bodies 1008 are produced on a dry offset metallic beverage container body decorating apparatus directly consecutively and continuously without manufacturing interruption in a direct single file queue. A first container body 1008 in the queue of container bodies will have one or more unique design elements that are visually distinguishable, as in casting different visual impression, relative to a directly subsequently produced substantially identical container body 1008 (i.e. conforming with typical manufacturing tolerances). Pairs of these consecutively decorated container bodies 1008 are illustrated, for example, in FIGS. 36 and 37, 40 and 41, and 44 and 45. These containers 1008, although produced consecutively, have different overall decorations provided by design elements that are unique to the individual containers 1008 in the pair.

(99) Each of the container bodies 1008 has an open end 1002 separated from a closed end 1006 by a circumferential side wall 1010. The circumferential side wall 1010 has an inner surface and an opposing outer surface 1014. The outer surface 1014 has a surface area that generally defines a surface area of the container body 1008 on which design elements may be applied.

(100) A first container body 1008 in the pair has a common design element 1018 on the outer surface 1014, a first unique design element 1022 in a first color on the outer surface 1014 defined by a first unique design element surface area, and a second unique design element 1026 in a second color on the outer surface 1014 defined by a second unique design element surface. The first unique design element surface area is located within the second unique design element surface area

(101) A second container body 1008 in the pair also has the common design element 1018 on its outer surface 1014. a third unique design element 1030 in the first color on the outer surface 1014 defined by a third unique design element surface area, and a fourth unique design element 1034 in the second color on the outer surface 1014 defined by a fourth unique design element surface area. The third and fourth unique design elements 1030,1034 are unique relative to the first and second design elements 1022,1026 on the first container body 1008. Further, the third unique design surface area is located within the fourth unique design surface area.

(102) The unique design elements on the beverage container bodies 1008 owe their relative uniqueness from the first container body 1008 to the second container body 1008 to unique design elements in high and low relief on image transfer blankets 5-l. The high relief portions receive ink from printing plates and display these design elements in the form of colors provided by the ink. The low relief portions do not receive ink from the printing plates and display design elements as an absence of ink wherein the uninked surface of the beverage container body 1008 forms a design element, typically surrounded by a color or colors of the common design element forming a border about the uninked design element.

(103) The common design element 1018 is identical from one container to the next. It has a substantially larger surface area than those of the unique design elements 1022,1026,1030,1034 wherein it dominates the overall impression of the decorated container bodies 1008. It will generally include a dominant background color. This dominant background color portion of the common design will preferably surround the unique design elements 1022,1026,1030,1034 such that unique design elements 1022,1026,1030,1034 lie entirely within the surface area of the common design element 1018.

(104) As will be described below, the common design elements generally owes their shape, color, and appearance to high relief portions of inked printing plates 3a-h. This process will be described in more detail below.

(105) The container bodies 1008 can exhibit several relationships between the pairs of unique design elements 1022,1026 and 1030,1034. For example, as illustrated in FIGS. 40 and 41 and 44 and 45, the first and third unique design element surface areas are located completely within boundaries of the second and fourth unique design element surface areas, respectively, and the first and third unique design element surface areas are greater than the second and fourth unique design element surface areas, respectively. As illustrated in FIGS. 36 and 37, the first and third unique design element surface areas can be substantially equal to the second and fourth unique design element surface areas, respectively, or the first and third unique design element surface areas can be less than the second and fourth unique design element surface areas, respectively.

(106) In the illustrated examples, the first and third unique design elements 1022,1030 are alphanumeric characters. The second and fourth unique design elements 1026,1034 are alphanumeric characters in the examples shown in FIGS. 36 and 37 and 40 and 41. In FIGS. 44 and 45, the second and fourth design elements are create borders about the alphanumeric characters of the first and third unique design elements 1022,1030, preferably with half-tone accenting or shading. Preferably, the first and second container bodies have multiple alphanumeric characters that spell out words, such as names and the like.

(107) Further to the examples, the second and fourth design elements 1026,1034 each take the color of an uninked outer surface 1014 of the first and second container bodies 1008. Typically, this uninked portion is the metallic color of the container body 1008. Meanwhile, the first and third design elements 1022,1030 each take a color of an ink supplied to the outer surface 1014 of the first and second container bodies 1008.

(108) In one embodiment, according to FIGS. 55 and 56, the first and second metallic beverage container bodies receive a wet ink on wet ink process. Here, the second and fourth unique design elements 1026,1034 are completely absent. The ink associated with the first and third design elements 1022,1030 is overlapped directly with an ink associated with the common design element 1018.

(109) The apparatuses and processes that create these decorative structures will be described in detail below.

(110) Dry Offset Rotary Decorating Apparatus

(111) A dry offset rotary style decorating apparatus 1 for creating the decorated beverage container bodies 1008 described immediately above is a typical decorating apparatus as previously described with modifications as will now be described. These modifications are made to at least one of the printing plates 3a-h (see FIGS. 46-48) and to the image transfer blankets 5a-l.

(112) The purpose of this apparatus 1 is to deliver a first overall decoration comprising unique design elements and a common design element from one image transfer blanket 5a to a first metallic beverage container body 1008. The apparatus 1 then delivers a second overall decoration comprising different unique design elements and the same common design element from a second image transfer blanket 5b to a second consecutively processed metallic beverage container body 1008. The first overall decoration is, thus, unique relative to the second overall decoration caused by the unique design elements.

(113) In this embodiment, the differences between the first overall decoration and the second overall decoration are accomplished by over-rotation of the container bodies 1008 against ink-bearing portions of the image transfer blankets 5a-l. In other words, the container bodies will make more than a 360 rotation against ink-bearing portions of the image transfer blankets 5a-l.

(114) As previously set forth, the apparatus has a plurality of ink applicators 2a-h. A plurality of printing plates 3a-h, where each printing plate 3a-3h has a print surface in high relief, engages a corresponding ink applicator of the plurality of ink applicators 2a-h and receives a quantity of fluid, i.e. ink, therefrom. The apparatus further comprises a plurality of image transfer blankets 5a-l rotationally mounted to the apparatus 1. The image transfer blankets 5a,b of this embodiment are illustrated in FIGS. 27-35, 38, 39, 42, 43, 48, and 49.

(115) One image transfer blanket 5a has an ink receiving surface 1038. The ink receiving surface 1038 sequentially engages each print surface of the plurality of printing plates 3a-h. High relief portions of the printing plates 3a-h engage high relief portions of the image transfer blankets 5a-l as illustrated in FIGS. 48 and 49. A first unique design element 1042 is in high relief relative to directly adjacent portions of the ink receiving surface 1038 bordering the first unique design element 1042. A second unique design element 1046 is in low relief within the ink receiving surface 1038. It is important to keep at least a 3 mm spacing between the second unique design element 1048 and any artwork apart from a background color of a common design element transferred from the printing plates 3a-h to the image transfer blankets 5a-l.

(116) Similarly, a second image transfer blanket 5b has a second ink receiving surface 1050. It engages the printing plates 3a-h in a like manner. A third unique design element 1054 is in high relief relative to directly adjacent portions of the second ink receiving surface 1050 bordering the third unique design element. The third unique design element 1054 is unique and distinctive relative to the first design element 1042 on the first image transfer blanket 5a. A fourth unique design element 1058 is in low relief within the second ink receiving surface 1050.

(117) The beverage container indexer 11 is mounted to the apparatus 1 in the conventional manner. The indexer 11 is rotationally mounted to the apparatus 1 and has a plurality of stations adapted for receiving a metallic beverage container body 1008 therein. The indexer 11 delivers the container bodies 1008 sequentially and continuously to a printing site 15 where the container bodies 1008 rotationally engage one image transfer blanket 5a such that the circumferential side wall 1010 of the container body 1008 completes at least a full 360 degree rotation, preferably more rotation as will be described, against the ink receiving surface 1038 and receives ink therefrom at the printing site 15. The indexer 11 transfers a container body 1008 from the printing site 15 while simultaneously transferring another container body 1008 to the printing site 15 where this container body engages a second single image transfer blanket 5b such the circumferential side wall 1010 of this container body 1008 also completes at least a full 360 degree rotation against ink receiving surface 1050 of the second image transfer blanket 5b and receives ink therefrom.

(118) In this embodiment of the invention, as illustrated in FIGS. 27-30, the container bodies 1008 complete more than a 360 degree rotation against ink-bearing portions of the ink receiving surfaces 1038,1050 of the image transfer blankets 5a,b. Typically, this additional rotation will be at least 6.5 rad, more preferably at least 6.6 rad, or enough to cause the surface areas of the first and third unique design elements 1042,1046 and the surface areas of the second and fourth unique design elements 1054,1058, respectively, to overlap during printing of the container bodies 1008. Accordingly, a distance between leading edges 1060 of the first and third design elements 1042,1054 and trailing edges 1062 of the second and fourth design elements 1046,1058 along a path parallel with a rotational movement of the image transfer blankets 5a,b are within ?10% of a length of a circumference of the metallic beverage containers processed on the apparatus 1.

(119) The ink receiving surfaces 1038,1050 on the image transfer blankets 5a-l also have an identical common design element 1064 in high relief. This common design element 1064 is created by the transfer of ink from high relief portions of the printing plates 3a-h to high relief portions of the ink receiving surfaces 1038,1050, in the embodiment illustrated. A distance between the leading edges 1060 of the first and third design elements 1042,1054 and a trailing edge 1070 of the common design element 1064 on the first and second ink receiving surfaces 1038,1050 is greater than or equal to a circumferential length of the container bodies plus a length of an arc of the container bodies 1008 subtending an angle of 15?, more preferably 20? or more. This arrangement allows the overlap of the surface areas of the unique design elements when the container bodies are over-rotated more than one complete revolution against ink-bearing surfaces of the image transfer blankets 5a-l.

(120) Thus, in the particular embodiment described herein, as the first and second container bodies 1008 are over-rotated more than one complete revolution against the ink receiving surfaces 1038,1050, they will first encounter an ink-bearing leading edge of the first and third unique design elements 1042,1054 in high relief. Trailing edges 1072 of the first and third unique design element 1042,1054 are separated from a leading edge 1073 of the common design element on the ink receiving surfaces 1038,1050 by a low relief portion of the ink receiving surface. The container bodies 1008 will then engage ink-bearing portions of the ink receiving surfaces 1038,1050 having the common design element 1064 thereon. A length of the common design element 1064 between the leading edge 1073 of the common design element and the trailing edge of the common design element is within ?5% of the length of the circumference of the container bodies, and the second and third unique design elements 1026,1058 are in low relief between the leading edge 1073 of the common design element 1064 and the trailing edge 1070 of the common design element 1064.

(121) Using the over-rotation of the container bodies 1008 against their respective image transfer blankets 5a-l, many decorating variations can be achieved. For example, the first, second, third, and fourth design elements 1042,1046,1054,1058 are defined by first, second, third, and fourth design element surface areas, respectively. The first and third unique design element surface areas may be less the second and fourth unique design element surface areas, respectively. The first and third unique design element surface areas may be substantially equal to the second and fourth unique design element surface areas, respectively. The first and third unique design element surface areas may be greater than the second and fourth unique design element surface areas, respectively.

(122) As discussed in conjunction with the container bodies 1008 themselves, the unique design elements may be alphanumeric characters. The first and second unique design elements 1042,1046 can be the same character, or the second unique design element 1046 character can create visual effects about the first unique design element 1022 (see FIG. 44). Likewise, third and fourth unique design elements can be the same character, or the fourth unique design element 1058 can create visual effects about the third unique design element 1054 (see FIG. 45). Clearly, from the drawings, the unique design elements 1042,1046,1054,1054 may comprise a plurality of alphanumeric characters each in order to spell names and the like.

(123) As shown in FIGS. 46 and 47, in this embodiment, one of the printing plates 3a has a band 1074 in high relief. This band 1074 engages the high relief of the first and third unique design elements 1042,1054 on the image transfer blankets 5a,b (see, e.g., FIG. 48).

(124) In one embodiment, according to FIGS. 50-56, the apparatus featuring over-rotation of the metallic beverage container bodies 1008 described above is used to print in a wet ink on wet ink process. Here, the second and fourth unique design elements 1042,1058 are not included on the first and second blankets 5a,b such that an ink from the ink patterns 1082,1090 received on the containers bodies 1008 from the first and third unique design elements 1042,1058 is overlapped directly with an ink of the ink pattern 1098 received from the common design element 1064.

(125) Method of Processing Container Bodies

(126) The invention is further directed to a method of producing the metallic beverage container bodies 1008 of, for example, FIGS. 36 and 37, on an apparatus 1 as described above using the principles of container body over-rotation, the unique and common design elements of the image transfer blankets, and the printing plate band 1074 described in conjunction with FIG. 48. Accordingly, the method is directed to consecutively decorating a plurality of substantially identical metallic beverage container bodies using a dry offset decorating apparatus. This method is carried out without manufacturing interruption.

(127) Thus, a queue of the container bodies 1008 is sequentially indexed to and through a printing site 15 on the dry offset decorating apparatus 1. As shown in FIGS. 27-30, a circumferential side wall 1010 of a first metallic beverage container body 1008 is brought into contact with the first ink receiving surface 1038 of the first image transfer blanket 5a. The first metallic beverage container body circumferential side wall 1010 is rotated at least 6.5 rad, more preferably at least 6.6 rad, while engaged with ink-bearing portions of the first ink receiving surface 1038 and along a length of the first ink receiving surface 1038 greater than a circumferential length of the first metallic beverage container body circumferential side wall 1010. Next, this process is repeated for a second metallic beverage container body 1008 directly behind the first metallic beverage container body 1008 in the queue, although contact of this container body 1008 is with a second image transfer blanket 5b.

(128) The first metallic beverage container body 1008 will have a resultant overall decoration that is unique relative to a resultant overall decoration exhibited by the second metallic beverage container body 1008 subsequent to the two engaging and rotating steps.

(129) Furthermore, according to the description of the first image transfer blanket 5a, the first unique design element 1042 is spaced from the second design element 1046 on the first ink receiving surface 1038. Rotation of the first metallic beverage container circumferential side wall 1010 by at least 6.2 radians against and along a length of the first ink receiving surface 1038 causes a first ink pattern 1082 associated with the first unique design element 1042 to be deposited on the first metallic beverage container side wall 1010 and causes a second ink pattern 1086 associated with the second unique design element 1046 to be deposited on the first metallic beverage container side wall 1010. The first ink pattern 1082 and the second ink pattern 1086 overlap.

(130) Likewise, the third unique design element 1054 of the second image transfer blanket 5b is spaced from the fourth design element 1058 on the second ink receiving surface 1050 such that the rotation of the second metallic beverage container circumferential side wall 1010 by at least 6.2 radians against and along a length of the second ink receiving surface 1050 causes a third ink pattern 1090 associated with the third unique design element 1054 to be deposited on the second metallic beverage container side wall 1010 and causes a fourth ink pattern 1094 associated with the fourth unique design element 1058 to be deposited on the second metallic beverage container side wall 1010. The third ink pattern 1090 and the fourth ink pattern 1094 overlap.

(131) The image transfer blankets 5a,b employed in this method have an identical common design element 1064 on the first and second ink receiving surfaces 1038,1050, respectively, and which forms a boundary around the second and fourth unique design elements 1046,1058 in low relief, respectively. The identical common design elements 1064 on the image transfer blanket blankets 5a,b are directly attributable to receiving an ink pattern from the high relief portions of each of the plurality of printing plates 3a-h and which directly create the common design element 1018 exhibited by the decorated container bodies 1008.

(132) More specifically, the ink applicators 2a-h are each supplied with a different color ink. Each printing plate 3a-h has a print surface in high relief. Each of the plurality of ink applicators 2a-2h transfers a quantity of ink to a corresponding printing plate 3a-h. Each of the plurality of printing plates 3a-h is then brought into engagement with the first ink receiving surface 1038 of the first image transfer blanket 5a to provide a common ink pattern 1098 associated with the identical common design element 1064 and to provide ink to the first unique design element 1042 in high relief prior to engaging the circumferential side wall 1010 of the first metallic beverage container body 1008 with the first ink receiving surface 1038 of the first image transfer blanket 5a. This action is repeated on the second image transfer blanket 5b.

(133) It further follows that the first and third ink patterns 1082,1090 are defined by first and third ink pattern surface areas, respectively. The second and fourth ink patterns 1086,1094 are defined by second and fourth ink patterns surface areas, respectively. The first and third ink pattern surface areas may be located completely within boundaries of the second and fourth ink pattern surface areas, respectively. (See FIGS. 44 and 45). The first and third ink pattern surface areas may be less than the second and fourth ink pattern surface areas, respectively. (See FIGS. 40 and 41). The first and third ink pattern surface areas may be substantially equal to the second and fourth ink pattern surface areas, respectively. The first and third ink pattern surface areas are greater than the second and fourth ink pattern surface areas, respectively. (See FIGS. 36 and 37). Furthermore, the second and fourth ink patterns 1086,1090 can be defined by an area having absence of ink bordered by the common design element 1064 ink pattern.

(134) In one embodiment, according to FIGS. 50-56, the method of the amount or degree of over-rotating the metallic beverage container bodies 1008 described above is used to print in a wet ink on wet ink process. Here, the second and fourth unique design elements 1042,1058 are not included on the first and second blankets 5a,b such that an ink from the ink patterns 1082,1090 received on the containers bodies 1008 from the first and third unique design elements 1042,1058 is overlapped directly with an ink of the ink pattern 1098 received from the common design element 1064.

(135) A preferred example of embodiment having been described, one should understand that the scope of the present invention embraces other possible variations, being limited only by the contents of the accompanying claims, which include the possible equivalents.

REFERENCE NUMBERS

(136) 1: printing apparatus 2a-2h: ink-holders 3a-3h: printing plates 4a-4h: plate cylinders 5a-5l: transfer blankets 6: transfer blanket drum 7: can chain 8: can 9: first directing wheel 10: first directing wheel 11: can carrying apparatus or beverage container indexer 12: central axle 13a-13c: artwork in low relief 66: an edge portion forming a transition between each of the plurality of low relief features and each of the corresponding high relief features on a transfer blanket 68: an edge portion forming a transition between opposite the edge 66 70: a wall separating the low relief features from the high relief features on a transfer blanket 80: a complex image exhibiting shading 84: an upper surface of a transfer blanket 88: high relief features on a transfer blanket 92: low relief features on a transfer blanket

(137) While the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying Claims.