Patent Publication Number: US-2021162733-A1

Title: Method for manufacturing beverage use can, beverage use can, and beverage can

Description:
TECHNICAL FIELD 
     The present invention relates to a method for manufacturing a beverage use can, a beverage use can, and a beverage can. 
     BACKGROUND ART 
     Patent Document 1 discloses forming images by inkjet printing on an outer surface of a seamless can. 
     CITATION LIST 
     Patent Literature 
     Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2012-232771 
     SUMMARY OF INVENTION 
     Technical Problem 
     Inkjet printing allows photo or similar images to be vividly printed on an outer circumferential surface of a beverage use can, as compared to the use of plate printing. Meanwhile, inkjet printing may produce some unclear printed images, such as outlines of character images becoming blurred. 
     An object of the present invention is to improve quality of images formed on an outer circumferential surface of a beverage use can. 
     Solution to Problem 
     A first aspect of the present invention relates to a method for manufacturing a beverage use can, the method including: forming an image on an outer circumferential surface of a can body by inkjet printing; and forming another image including a character image on the outer circumferential surface of the can body by plate printing, the another image being formed in an area that is smaller than another area in which the image is formed by inkjet printing. 
     The image formed by the inkjet printing may be formed over an entirety of the outer circumferential surface of the can body, and the another image including the character image formed by the plate printing may be formed on a portion of the outer circumferential surface of the can body. 
     Image formation by the inkjet printing and image formation by the plate printing may be performed such that the image formed by the inkjet printing and the another image formed by the plate printing do not overlap each other. 
     Image formation by the plate printing may be performed after image formation by the inkjet printing. 
     The inkjet printing may include forming, on the outer circumferential surface of the can body, the image including a photo image. 
     The plate printing may include forming, on the outer circumferential surface of the can body, the another image including the character image that represents at least one of information on a manufacturer and information on contents in the can body. 
     A second aspect of the present invention relates to a method for manufacturing a beverage use can, the method including: forming an image on an outer circumferential surface of a can body by inkjet printing; and forming another image including a trademark and/or a code image on the outer circumferential surface of the can body by plate printing, the another image being formed in an area that is smaller than another area in which the image is formed by inkjet printing. 
     A third aspect of the present invention relates to a method for manufacturing a beverage use can, the method including: forming an image on an outer circumferential surface of a can body by inkjet printing; and forming another image in an area on the outer circumferential surface of the can body by plate printing, the area extending in an axial direction of the can body, the area being smaller than another area in which the image is formed by inkjet printing. 
     The area extending in the axial direction may include a plurality of the areas extending in the axial direction, the plurality of the areas being located at mutually different positions in a circumferential direction of the can body, and a sum of the plurality of the areas extending in the axial direction may be smaller than the another area in which the image is formed by inkjet printing. 
     Image formation by the plate printing may be performed after image formation by the inkjet printing. 
     The image formed by the inkjet printing may be formed over an entirety of the outer circumferential surface of the can body, and then the another image formed by the plate printing may be formed on the image formed by the inkjet printing. 
     A fourth aspect of the present invention relates to a method for manufacturing a beverage use can, the method including: forming a multi-level image on an outer circumferential surface of a can body by inkjet printing, the multi-level image being included in images to be formed on the outer circumferential surface; and forming a binary image by plate printing in an area that is smaller than another area in which the multi-level image is formed by inkjet printing. 
     A fifth aspect of the present invention relates to a beverage use can including: a can main body of a cylindrical shape; an image part formed on an outer circumferential surface of the can main body, the image part being formed by inkjet head printing; another image part formed on the outer circumferential surface of the can main body, the another image part being smaller in area than the image part, the another image part being formed by plate printing, the another image part including at least one of a character image, a trademark, and a code image. 
     A sixth aspect of the present invention relates to a beverage use can including: a can main body of a cylindrical shape; an overall image formed on an outer circumferential surface of the can main body such that the overall image extends in a circumferential direction of the can main body, the overall image being formed by inkjet head printing; and a partial image formed on a portion of the outer circumferential surface of the can main body, the partial image including at least one of a character image, a trademark, and a code image, the partial image being formed by plate printing. 
     A seventh aspect of the present invention relates to a beverage can including: the beverage use can according to the above fifth or sixth aspect; and contents in the beverage use can. 
     Advantageous Effects of Invention 
     The present invention allows to improve quality of images formed on an outer circumferential surface of a beverage use can. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a beverage use can. 
         FIG. 2  is a developed view of printed images formed on an outer circumferential surface of a can body. 
         FIG. 3  shows printed images formed by inkjet printing among the printed images. 
         FIG. 4  shows printed images formed by plate printing among the printed images. 
         FIG. 5  is a developed view of other exemplary printed images formed on the outer circumferential surface of the beverage use can. 
         FIG. 6  shows printed images formed by inkjet printing among the printed images. 
         FIG. 7  shows printed images formed by plate printing among the printed images. 
         FIG. 8  is a side view of a printing apparatus. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     An embodiment of the present invention will be described below with reference to the drawings. 
       FIG. 1  is a perspective view of a beverage use can  100  according to the present embodiment. 
     The beverage use can  100  of the present embodiment includes a cylindrical can main body (can body)  200 . The can main body  200  includes a round opening  210  at its upper portion. The can main body  200  further includes a bottom  220  at its lower portion. The can main body  200  further includes an outer circumferential surface  230 . 
     Plate printing and inkjet printing are performed on the outer circumferential surface  230 , whereby printed images are formed the outer circumferential surface  230 . 
     In the present embodiment, a beverage as the contents of the beverage use can  100  is filled into the can main body  200  through the opening  210  at its upper portion. Then, the opening  210  is closed by a can lid (not shown). This completes a beverage can filled with the beverage. 
     The beverage use can  100  refers to an empty can before being filled with the beverage, and the beverage can refers to a can after being filled with the beverage as the contents thereof. 
     The can main body  200  is made of a metal material. Specifically, the can main body  200  is made of, for example, aluminum or aluminum alloy. Alternatively, the can main body  200  is made of, for example, iron alloy such as tin-free steel. The can main body  200  is formed by, for example, drawing and ironing (DI) of a flat plate material or stretching and drawing of the flat plate material. 
     Examples of the beverage filled into the can main body  200  include alcoholic beverages such as beer and non-alcoholic beverages such as soft drinks. 
       FIG. 2  is a developed view of printed images formed on the outer circumferential surface  230  of the can main body  200 .  FIG. 3  shows printed images formed by inkjet printing among the printed images shown in  FIG. 2 .  FIG. 4  shows printed images formed by plate printing among the printed images shown in  FIG. 2 . 
     The printed images of the present embodiment (the printed images shown in  FIG. 2 ) are composed of a superposition of those shown in  FIG. 3  and those shown in  FIG. 4 . 
     As shown in  FIG. 3 , in the present embodiment, images formed by inkjet printing (hereinafter each referred to as an “inkjet-printed image”) are formed on the outer circumferential surface  230  of the can main body  200  over the entirety of the outer circumferential surface  230 . 
     In other words, the inkjet-printed image is an example of the overall image and formed almost over the entire outer circumferential surface  230  of the can main body  200 . Additionally, the inkjet-printed image is formed in a belt-like shape so as to extend in the circumferential direction of the can main body  200 . 
     In the present embodiment, inkjet printing is performed over the entirety of the outer circumferential surface  230  of the can main body  200  to form the inkjet-printed images (images shown in  FIG. 3 ) thereon. 
     In the present embodiment, plate printing is then performed on these inkjet-printed images to form images thereon by plate printing (the images shown in  FIG. 4 ; hereinafter each referred to as a “plate-printed image”). 
     Here, the inkjet-printed images are formed first, followed by the plate-printed images. However, the order of image formation is not limited to this; the plate-printed images may be formed first, followed by the inkjet-printed images. 
     As shown in  FIG. 3 , in the present embodiment, photo images  3 C are formed as part of the inkjet-printed images. 
     The photo images  3 C are images formed based on photo data. It should be noted that the photo images  3 C include not only those obtained from the photo data itself but also those formed based on data that is processed from the photo data. Processing the photo data includes adding an additional image(s) to the photo data. 
     In other words, in the present embodiment, multi-level images among the images to be formed on the outer circumferential surface  230  of the can main body  200  are formed by inkjet printing. 
     The multi-level images include color and gray-scale images. Forming these multi-level images by inkjet printing can make them more vivid than when they are formed by plate printing. 
     Meanwhile, in the present embodiment, binary images including character images (described later) and single-colored code images (described later) are formed by plate printing, among the images formed on the outer circumferential surface  230  of the can main body  200 . 
     Referring to  FIG. 4 , a description will be given of images formed by plate printing (plate-printed images). 
     As shown in  FIG. 4 , in the present embodiment, the plate-printed images are formed in areas that are smaller than the area where the inkjet-printed images are formed. 
     Specifically, in the present embodiment, the inkjet-printed images are formed over the entirety of the outer circumferential surface  230  of the can main body  200  (see  FIG. 3 ), whereas the plate-printed images are formed on portions of the outer circumferential surface  230  of the can main body  200 , as shown in  FIG. 4 . 
     More specifically, the plate-printed images are formed in first to eighth formation areas E 11 -E 18  on the outer circumferential surface  230  of the can main body  200 , instead of over the entirety of the outer circumferential surface  230 . In other words, in the present embodiment, each of the plate-printed images can be regarded as a partial image that is formed on a portion of the outer circumferential surface  230  of the can main body  200 . 
     The first formation area E 11  and the second formation area E 12  are rectangular (belt-like) areas extending in the axial direction of the can main body  200 . The first formation area E 11  and the second formation area E 12  are laid out from one end  211  (see  FIG. 1 ) to the other end  212  of the can main body  200  in the axial direction thereof. Also, the first formation area E 11  and the second formation area E 12  are located at mutually different positions in the circumferential direction of the can main body  200 . 
     In the present embodiment, the sum of the areas of the first formation area E 11  and the second formation area E 12  is smaller than the area where the inkjet-printed images are formed (the area inside a rectangular dashed line denoted by  3 A in  FIG. 3 ). 
     It should be noted that the number of formation areas extending in the axial direction of the can main body  200  may be one or three or more, instead of two (the first formation area E 11  and the second formation area E 12 ) in the present embodiment. 
     As shown in  FIG. 4 , in the present embodiment, a trademark “ABC Draft Beer” is formed in each of the third formation area E 13  and the fourth formation area E 14  as part of the plate-printed images. 
     The fifth formation area E 15  and the sixth formation area E 16  have a round shape. A character image “alcohol” representing the kind of contents in the can main body  200  is formed in each of the fifth formation area E 15  and the sixth formation area E 16 . 
     Also, a character image “draft beer (non-heat treated)” representing the kind of contents in the can main body  200  is formed in each of the seventh formation area E 17  and the eighth formation area E 18 . 
     The shape of each of the first to the eighth formation areas E 11 -E 18  is not limited to a particular shape and may be a circle, an ellipse or a polygon. Beside these, any irregular shape may also be used. Example of the polygon include triangle and square. Pentagon or more-sided polygons may also be used. 
     In the present embodiment, formation of the plate-printed images (formation of images by plate printing) is performed after formation of the inkjet-printed images (formation of images by inkjet printing). 
     This makes the plate-printed images come on the front side as compared to when the plate-printed images are formed prior to the inkjet-printed images. This makes clearer the character images and the like included in the plate-printed images. 
     It should be noted that formation of the plate-printed images is not necessarily performed after formation of the inkjet-printed images; the plate-printed images may be formed prior to the inkjet-printed images. 
     The image formation by inkjet printing refers to a printing method in which ink is ejected from inkjet heads  411  and applied onto the can main body  200 . 
     Any known method may be used for image formation by inkjet printing. Specifically, use may be made of piezoelectric inkjet, thermal (bubble) inkjet, continuous inkjet and the like. 
     The image formation by plate-printing refers to a printing method using a plate. More specifically, in this method, ink is applied to a plate and then transferred from the plate onto the can main body  200  for printing on the can main body  200 . 
     The ink may be transferred onto the can main body  200  by direct contact between the plate and the can main body  200  or via an intermediate transfer body disposed between the plate and the can main body  200 . 
     Example of the plate printing include letterpress printing, intaglio printing, planographic printing, and stencil printing. Any of these methods may be used for the plate printing. In the present embodiment, the plate-printed images are formed by letterpress printing. 
     Referring to  FIG. 4 , a detailed description will be given of the first formation area E 11  and the second formation area E 12 . 
     Character images are formed in the first formation area E 11 . 
     More specifically, a character image (character string) representing information on the contents in the beverage use can  100  (the part denoted by  4 A), a character image representing a manufacturer (the part denoted by  4 B), and a character image representing contact information (the part denoted by  4 C) are formed. 
     The character image representing information on the contents include a list of raw materials of the contents as denoted by 4D and a list of nutrition facts as denoted by  4 E. 
     A character image is also formed in the second formation area E 12 . 
     Specifically, a character image representing a notice for use (the part denoted by  4 F) is formed in the second formation area E 12 . 
     A code image as denoted by  4 G is also formed in the second formation area E 12 . The code image refers to an image of encoded numerical values and characters. The code image includes a bar code consisting of parallel bar images and other form of code images such as two-dimensional bar code. 
     An image about recycling as denoted by  4 H is also formed in the second formation area E 12 . 
     As described above, the present embodiment exemplarily shows the case where multiple kinds of character images are formed, including one representing information on the contents, one representing the manufacturer and one representing contact information. However, not all of these character images are essential; any or some of them may be removed and also another character image representing other information may be added. 
     In the above description, the plate-printed images are formed on the inkjet-printed images. In other words, the inkjet-printed images and the plate-printed images overlap each other. 
     However, the way of printing is not limited to this; the inkjet-printed images and the plate-printed images may be formed such that they do not overlap each other. 
     Specifically, for example, the inkjet-printed images may not be formed on portions where the plate-printed images are to be formed (i.e., the inkjet-printed images may be formed so as to leave blank the portions where the plate-printed images are to be formed), and then the plate-printed images may be formed on these portions. 
     Alternatively, for example, areas where the inkjet-printed images are to be formed may be distinctively separated from areas where the plate-printed images are to be formed, and the inkjet-printed images and the plate-printed images may be formed in respective areas. 
     Inkjet printing allows photo or similar images to be vividly printed on the outer circumferential surface  230  of the can main body  200 , as compared to the use of plate printing. 
     Meanwhile, inkjet printing of those images that need to be clearly outlined, such as character images and trademarks, may result in the outline of these images becoming blurred. In view of this, in the present embodiment, those images that need to be clearly outlined, such as character images and trademarks, are formed by plate printing as described above. This makes the outline of these images clear, improving the quality of images formed on the can main body  200 . 
     In the present embodiment, comparing the formation area for the inkjet-printed images and the formation area for the plate-printed images, the latter is smaller than the former. 
     In other words, comparing an area of ink applied onto the can main body  200  by inkjet printing and an area of ink applied onto the can main body  200  by plate printing, the latter is smaller than the former. 
     In the present embodiment, this allows for easier formation of images on the can main body  200  as compared to when the formation area for the plate-printed images is larger than the formation area for the inkjet-printed images. 
     Forming images by plate printing requires a plate. It also requires installation of the plate and color matching. This involves a large workload and cost. In particular, use of a larger plate often involves a larger workload and cost. 
     In contrast, in the present embodiment, the plate-printed image formation area is smaller than the inkjet-printed image formation area, as described above. This allows to more easily and inexpensively prepare a plate for plate printing as compared to when the plate-printed image formation area is larger than the inkjet-printed image formation area. Additionally, this smaller plate-printed image formation area allows to reduce workload of color matching and the like, as compared to when the plate-printed image formation area is larger than the inkjet-printed image formation area. 
       FIG. 5  is a developed view of other exemplary printed images formed on the outer circumferential surface  230  of the beverage use can  100 .  FIG. 6  shows printed images formed by inkjet printing among the printed images shown in  FIG. 5 .  FIG. 7  shows printed images formed by plate printing among the printed images shown in  FIG. 5 . 
     The printed images shown in  FIG. 5  are composed of a superposition of those shown in  FIG. 6  and those shown in  FIG. 7 . 
     As shown in  FIG. 6 , in this example too, the inkjet-printed images are formed almost over the entirety of the outer circumferential surface  230  of the can main body  200 . 
     The inkjet-printed images include a photo image  3 C similarly to the above example. More specifically, the inkjet-printed images include a photo image  3 C representing a temple. 
     As shown in  FIG. 7 , in this example too, plate-printed images are formed on the outer circumferential surface  230  of the can main body  200 . More specifically, in this example, the plate-printed images are formed in five formation areas of first to fifth formation areas E 21 -E 25 . 
     The first formation area E 21  has a rectangular shape extending in the axial direction of the can main body  200 . As denoted by  7 A, a character image representing a text for explaining the image (the image of the temple) included in the inkjet-printed images is formed in the first formation area E 21 . Similarly to the above example, a character image as denoted by  7 B representing information on the contents in the can main body  200  is formed in the first formation area E 21 . Also, a code image as denoted by  7 C and a character image representing a manufacturer as denoted by 7D are formed in the first formation area E 21 . 
     As shown in  FIG. 7 , a character image “alcohol” representing the kind of contents in the can main body  200  is formed in the second formation area E 22 . A character image representing the contents in the can main body  200  is formed in the third formation area E 23 . 
     A trademark is formed in the fourth formation area E 24 . Another trademark is formed in the fifth formation area E 25 . 
     Now a description will be given of a printing apparatus  400  for forming the inkjet-printed images and the plate-printed images. 
       FIG. 8  is a side view of the printing apparatus  400 . 
     The printing apparatus  400  includes an inkjet printing part  410  that forms images by inkjet printing (inkjet printing process) and a plate printing part  450  that forms images by plate printing (plate printing process). The printing apparatus  400  further includes a can conveying mechanism  490  that conveys the can main bodies  200  in the direction of an arrow  8 A in the figure. 
     The plate printing part  450  is located downstream of the inkjet printing part  410  in the conveying direction of the can main bodies  200 ; in the present embodiment, plate printing is performed after inkjet printing. 
     The inkjet printing part  410  includes four inkjet heads  411 . Specifically, the inkjet printing part  410  includes a first inkjet head  411 Y ejecting yellow ink, a second inkjet head  411 M ejecting magenta ink, a third inkjet head  411 C ejecting cyan ink, and a fourth inkjet head  411 K ejecting black ink. 
     The four inkjet heads  411  are positioned so as to extend in a direction perpendicular to the conveying direction of the can main bodies  200  (a direction perpendicular to the paper plane in the figure). Further, each of the four inkjet heads  411  is positioned so as to extend along the axial direction of the conveyed can main bodies  200 . 
     Each of the four inkjet heads  411  is positioned above the conveying route of the can main body  200  and ejects ink onto the can main body  200  located below. 
     The can conveying mechanism  490  includes multiple moving units  491 . Each moving unit  491  includes a mandrel  491 A for supporting the can main body  200 . The mandrel  491 A is formed in a cylindrical shape and inserted into the can main body  200 . Each moving unit  491  includes a motor (not shown) for rotating the mandrel  491 A. 
     The can conveying mechanism  490  further includes a moving mechanism (not shown) for moving the moving units  491 . 
     The moving mechanism may be a linear moving mechanism, for example. When a linear moving mechanism is used, an electromagnet is placed along a moving route of each moving unit  491  and a magnet is placed on each moving unit  491 . Controlling the energization of the electromagnet allows each moving unit  491  to be moved. 
     Besides the linear moving unit, the moving mechanism may be any other known moving mechanism. Alternatively, each moving unit  491  may be mounted with a driving source such as a motor so as to move by itself. 
     The plate printing part  450  includes multiple plate cylinders  451 . Each plate cylinder  451  includes, on its surface, projections (not shown) corresponding to the plate-printed images. The plate printing part  450  further includes multiple ink supply units  452  for supplying ink onto the projections of each plate cylinder  451 . 
     The plate printing part  450  further includes a blanket  453  to which the ink is transferred from the plate cylinders  451  and that transfers the ink to each can main body  200 . 
     The printing apparatus  400  sequentially conveys each can main body  200  to the downstream side using the can conveying mechanism  490 . The can main body  200  is stopped below each of the four inkjet heads  411  and rotated in the circumferential direction. 
     In this state, ink is ejected from each inkjet head  411  onto the can main body  200  located below. Thus, in the present embodiment, color inkjet-printed images are formed on the outer circumferential surface  230  of the can main body  200  as it passes below the four inkjet heads  411 . 
     In the present embodiment, the can main body  200  then moves to the print printing part  450 , at which the can main body  200  is temporarily stopped. Further, the can main body  200  is rotated. 
     At the print printing part  450 , ink is supplied from the ink supply units  452  onto the surfaces of the corresponding plate cylinders  451 . The ink applied on the surface of each plate cylinder  451  (the ink applied on the projections of each plate cylinder  451 ) is then transferred onto the blanket  453 . The ink transferred onto the blanket  453  is in turn transferred onto the can main body  200  being rotated. This forms the plate-printed images on the outer circumferential surface  230  of the can main body  200 . 
     When the plate-printed images have a single color, use is made of a single ink supply unit  452  and a single plate cylinder  451  corresponding to the single ink supply unit  452 . When the plate-printed images have two or more colors, use is made of multiple ink supply units  452  and multiple plate cylinders  451 . 
     In the present embodiment, the plate-printed images of trademarks are formed in a single color and the other plate-printed images are formed in another single color; the plate-printed images are thus composed of two colors. Hence, in the present embodiment, use is made of two ink supply units  452  and two plate cylinders  451 . 
     The present embodiment has described the case where the inkjet printing part  410  is located on the upstream side and the plate printing part  450  is located on the downstream side; when, however, the inkjet-printed images are to be formed after the plate-printed images, the positions of the printings parts are exchanged. That is, the plate printing part  450  is located on the upstream side and the inkjet printing part  410  is located on the downstream side. 
     Although not shown in the above figures, a white or other colored underlayer may be formed on the outer circumferential surface  230  of the can main body  200  when necessary prior to formation of the inkjet-printed images and the plate-printed images. 
     Although not shown in the figures, a curing process is performed downstream of the inkjet printing part  410  and the plate printing part  450 , whereby the can main body  200  is heated or UV-irradiated to cure the inkjet-printed images and the plate-printed images thereon. 
     Although not shown in the figures, a protective layer forming process is also performed downstream of the inkjet printing part  410  and the plate printing part  450 , whereby a paint is applied on the inkjet-printed images and the plate-printed images to form a protective layer thereon. 
     While in the above description the two printing parts of the inkjet printing part  410  and the plate printing part  450  are provided in the single printing apparatus  400 , there may be installed two printing apparatuses  400  one of which performs inkjet printing and the other of which performs plate printing. 
     While in the above description the can main bodies  200  are linearly moved and conveyed in the printing apparatus  400  of the present embodiment, the can main bodies  200  may be moved along an annular route and the inkjet-printed images and the plate-printed images may be formed on the can main bodies  200  during their movement along the annular route. 
     REFERENCE SIGNS LIST 
     
         
           3 C Photo image 
           100  Beverage use can 
           200  Can main body (can body) 
           230  Outer circumferential surface 
           410  Inkjet printing part (inkjet printing process) 
           450  Plate printing part (plate printing process)