JP7661697B2 - Can container and its manufacturing method - Google Patents

Description

The present invention relates to a can container and a method for manufacturing the same.

It is known to form an image by printing directly onto a can body using an inkjet head (Patent Document 1).
[Patent Document 1] JP 2019-108138 A

In a first aspect of the present invention, a can container is provided that includes a cylindrical can body, an inkjet-printed image layer that covers at least a portion of the outer periphery of the can body, and a resin film that covers the can body and the inkjet-printed image layer.

In a second aspect of the present invention, a can container is provided that includes a cylindrical can body, a digitally printed image layer that covers at least a portion of the outer periphery of the can body, a resin film that covers the can body and the digitally printed image layer, and a varnish layer that covers at least a portion of the resin film.

In addition, in a third aspect, a method for manufacturing a can container is provided that includes a label attachment step of attaching a printed label including an inkjet printed image layer and a resin film so as to cover at least a portion of the outer peripheral surface of the can body.

Note that the above summary of the invention does not list all of the necessary features of the present invention. Also, subcombinations of these features may also be inventions.

An example of a can container 10 in this embodiment is shown. An example of the layer structure of the can container 10 in this embodiment is shown. An example of the layer structure of the can container 10 in this embodiment is shown. An example of the layer structure of the can container 10 in this embodiment is shown. An example of the layer structure of the can container 10 in this embodiment is shown. An example of the layer structure of the can container 10 in this embodiment is shown. An example of the layer structure of the can container 10 in this embodiment is shown. An example of a flow of a manufacturing method of the can container 10 of this embodiment by wet molding will be shown. 11 shows an example of a sub-flow of the wet molding step S100 in this embodiment. An example of a flow of a manufacturing method of the can container 10 of this embodiment by dry molding will be shown. 11 shows an example of a sub-flow of the dry molding step S110 in this embodiment.

The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

Figure 1 shows an example of a can container 10 in this embodiment. A pattern or the like is formed on the can container 10 by digital printing such as inkjet printing. The can container 10 has a lid portion 100, a body portion 200, and a bottom portion 300.

The lid 100 is provided at one end of the can container 10. The top surface of the lid 100 is open so that the contents can be filled. After the contents are filled, a lid including a drinking spout or the like is placed on the lid 100, and the lid may be fixed by seaming or the like. The lid 100 may have a tapered portion in which the outer diameter is reduced from the body 200 side toward the end.

The body 200 is located between the lid 100 and the bottom 300, and occupies most of the can container 10. The body 200 may have a substantially constant outer diameter in the longitudinal direction of the can container 10. Digitally printed letters, symbols, repeating patterns, design patterns, and designs (also referred to as "designs, etc.") are provided on the body 200. In the example of FIG. 1, a design 400 and letters 500 are printed on the body 200.

The bottom 300 is provided on the other end side of the can container 10 and is formed in a dome shape. The bottom 300 enables the can container 10 to stand upright when placed upright. The bottom 300 may have a constant outer diameter or may have a reduced diameter.

The can container 10 shown in FIG. 1 may typically be a can for beverages, but is not limited thereto. For example, the can container 10 may be a food can such as a can containing food or oil, a 18L can, or an industrial can containing medicines, reagents, industrial products, etc. The shapes of the lid 100, body 200, and bottom 300 shown in FIG. 1 are examples of beverage cans, and are not limited thereto. In addition, the can container 10 is not limited to a can before it is filled with contents, but may also include a can after it has been filled with contents and an empty can after the contents have been consumed.

Figure 2 shows an example of the layer structure of the can container 10 in this embodiment. For example, the can container 10 may have the layer structure shown in Figure 2 in the can body 200. In addition, the can container 10 may also have the layer structure shown in Figure 2 on the side of the lid 100 and/or bottom 300.

The can container 10 has a can body 20, a printed label 30, and an adhesive layer 40. The contents filled in the can container 10 are located on the can body 20 side (lower side of the drawing). The can container 10 is in contact with the outside air on the printed label 30 side (upper side of the drawing). Hereinafter, the can body 20 side is referred to as the inner surface, and the printed label 30 side is also referred to as the outer surface.

The can body 20 is the basic structure of the can container 10 and provides sufficient strength to the can container 10. The can body 20 is formed in a cylindrical shape. The can body 20 may be formed of a seamless can or a welded can. The surface of the can body 20 may be smooth or may be provided with irregularities (e.g., bead processing, embossing, and/or diamond cutting, etc.). The material of the can body 20 may be an aluminum can, a steel can, or other metal. The can body 20 may be surface-treated (e.g., oxide film treatment).

The printed label 30 is a film-like member on which a pattern or the like is printed, and covers at least a portion of the outer circumferential surface of the can body 20. In this way, the printed label 30 imparts a pattern or the like to the can container 10 even if the can body 20 is not directly printed on.

The printed label 30 may be provided on a part or the entire body 200 of the can body 20. The printed label 30 may be provided on a part or the entire lid 100 of the can body 20. The printed label 30 may be provided on a part or the entire bottom 300 of the can body 20. The printed label 30 includes a resin film 32 and a digitally printed image layer 34.

In the can container 10, the resin film 32 covers the can body 20 and the digitally printed image layer 34. The resin film 32 is disposed on the outer peripheral surface side of the printed label 30, and protects the digitally printed image layer 34 from physical damage. Furthermore, if the can container 10 is a beverage can or a food can, a retort process is performed for sterilization. In such a case, the resin film 32 prevents the digitally printed image layer 34 from coming into contact with moisture.

The resin film 32 may be a transparent film. For example, the resin film 32 may be a film that can be used as a transparent barrier film. As an example, the resin film 32 may be an oriented polypropylene (PP), oriented polyethylene terephthalate (PET), or oriented nylon film. In particular, it is preferable that the resin film 32 is a PET film.

The resin film 32 may also be surface-treated. For example, the resin film 32 may be a corona-treated film. Corona treatment can improve the adhesion between the resin film 32 and the digitally printed image layer 34. The thickness of the resin film 32 may be in the range of 1 to 100 μm, and preferably 5 to 50 μm.

The digitally printed image layer 34 constitutes a pattern or the like. The digitally printed image layer 34 is formed on the inner surface of the printed label 30 and covers at least a portion of the outer surface of the can body 20. The digitally printed image layer 34 may be formed by digital printing. For example, examples of digital printing include inkjet printing and electrophotographic printing.

The digitally printed image layer 34 may include an ink component for inkjet printing or a toner component for electrophotographic printing. As an example, when formed by inkjet printing, the digitally printed image layer 34 may be an inkjet printed image layer including a resin component and a pigment or dye. The digitally printed image layer 34 may include other additives. As an example, when formed by electrophotographic printing, the digitally printed image layer 34 may be an electrophotographic printed image layer including a resin component, a pigment, and a wax.

The digitally printed image layer 34 may be a layer on which a single-color image or the like is printed, or a layer on which a multi-color image or the like is printed. The digitally printed image layer 34 may be made up of multiple layers. For example, the digitally printed image layer 34 may be made up of two layers, a first layer and a second layer.

The first layer is located closer to the resin film 32 than the second layer, and is located on the outer surface side of the can container 10 after being attached to the can body 20. The first layer may form a pattern or the like. The second layer functions as a base and may form, for example, a solid pattern of a single color such as white, a repeating pattern such as stripes or a checkerboard pattern, or a pattern or the like. In one embodiment, one of the first layer and the second layer may be formed by plate printing such as gravure printing rather than digital printing. The digitally printed image layer 34 may be three or more layers.

The thickness of the digitally printed image layer 34 may be 0.1 μm or more and 20 μm or less. Preferably, the thickness of the digitally printed image layer 34 may be 0.5 μm or more and 10 μm or less.

The adhesive layer 40 adheres the printed label 30 to the can body 20. The adhesive layer 40 may be a cured adhesive or a cured semi-cured film. For example, the adhesive layer 40 may be a cured acrylic resin adhesive, a polyurethane resin adhesive, a polyester resin adhesive, or an epoxy resin adhesive.

According to this embodiment, instead of printing directly on the can body 20, a digitally printed print label 30 is used to apply a pattern or the like to the can container 10. This makes it easier to print a pattern or the like than printing directly on the can body 20, and since the pattern or the like can be prepared in parallel with the molding of the can container 10, the productivity of the can container 10 having various patterns or the like can be improved. In particular, even if there is a difference in productivity between the can manufacturing process and the digital printing process, the can container 10 can be manufactured without impairing the productivity of the can manufacturing line. In addition, even under conditions where direct printing is relatively difficult, such as when the can body 20 has unevenness, a pattern or the like can be applied to the can body 20. In particular, when the print label 30 is printed by inkjet printing, different patterns can be printed immediately on each of the can bodies 20, so that a can container 10 having a variety of patterns or the like can be easily provided. In particular, when the print label 30 is printed by electrophotographic printing, printing can be performed faster than conventional gravure printing and flexo printing, as with inkjet printing, so that a can container 10 having a variety of patterns or the like can be provided in a short time.

Figure 3 shows an example of the layer structure of the can container 10 in this embodiment. The can container 10 in Figure 3 further has a varnish layer 50 in addition to the can container 10 in Figure 2.

The varnish layer 50 covers at least a portion of the resin film 32. The varnish layer 50 protects the can body 20 from external impacts and the like. When performing retort processing, films such as the resin film 32 may become cloudy and white due to high temperature and moisture. By providing the varnish layer 50, it is possible to prevent the resin film from becoming cloudy and white.

The varnish layer 50 may be provided on at least the can body 200 of the can container 10. The varnish layer 50 may be formed so as to cover the entire or part of the resin film 32 of the can container 10.

The varnish layer 50 may contain a resin component. The resin component may contain a cured thermosetting acrylic resin, a thermosetting epoxy resin, or a thermosetting polyester resin, but from the viewpoint of transparency, a thermosetting epoxy resin may be used. The varnish layer 50 may further contain one or more selected from olefin-based hydrocarbons, paraffin-based hydrocarbons, oils and fats, wax, synthetic polymer-based resins, and organic fluorine compounds (hereinafter also referred to as "wax, etc."), but is not limited thereto. The varnish layer 50 may further contain a known additive. Examples of additives include a leveling agent, an antifoaming agent, a cissing inhibitor, a fluorine-based compound, and a silicon-based compound. The thickness of the varnish layer 50 may be 0.5 μm or more and 15 μm or less. If the thickness of the varnish layer is less than 0.5 μm, the protective effect of the can body 20 and the effect of preventing the resin film from becoming cloudy are insufficient, and if the thickness exceeds 15 μm, the production speed decreases and a large amount of material is consumed, which is disadvantageous in terms of cost.

Figure 4 shows an example of the layer structure of the can container 10 in this embodiment. The can container 10 in Figure 4 further has an inner surface protective layer 60 in addition to the can container 10 in Figure 3. As an alternative to the structure in Figure 4, some layers such as the varnish layer 50 may not be provided. The inner surface protective layer 60 protects the inner surface of the can body 20 and prevents the contents from coming into contact with the can body 20 and causing a reaction, etc.

The inner surface protective layer 60 may be formed by curing a known paint. The inner surface protective layer 60 may also be a polyester film heat-pressed onto the can body 20 or a resin film similar to the resin film 32.

Figure 5 shows an example of the layer structure of the can container 10 in this embodiment. The printed label 30 of the can container 10 in Figure 5 further has a resin film 36 in addition to the resin film 32 and the digitally printed image layer 34. As an alternative to the configuration in Figure 5, some layers such as the varnish layer 50 and/or the inner surface protective layer 60 may not be provided.

The digitally printed image layer 34 is sandwiched between the resin film 32 and the resin film 36. This provides more robust protection for the digitally printed image layer 34. For example, it is possible to more reliably prevent the digitally printed image layer 34 from coming into contact with moisture during retort processing, etc.

The resin film 36 may be the same film as the resin film 32. Alternatively, it may be a different film. For example, the resin film 32 may be selected with emphasis on the protection function of the can container 10, and the resin film 36 may be selected with emphasis on adhesion to the digitally printed image layer 34 and/or the adhesive layer 40. As an example, the resin film 32 may be thicker than the resin film 36. The resin film 36 may be opaque, but when a base layer 38 described later is provided, it is desirable that the resin film 36 is transparent so that the base can be visualized. If necessary, an adhesive layer made of an adhesive or the like may be further provided between the digitally printed image layer 34 and the resin film 36.

Figure 6 shows an example of the layer structure of the can container 10 in this embodiment. The printed label 30 of the can container 10 in Figure 6 further has a base layer 38 in addition to the resin film 32, the digitally printed image layer 34, and the resin film 36. As an alternative to the configuration in Figure 6, some layers such as the resin film 36, the varnish layer 50, and/or the inner surface protective layer 60 may not be provided.

The undercoat layer 38 is formed between the can body 20 and the digitally printed image layer 34, and serves as a base for the digitally printed image layer 34. The undercoat layer 38 may be a pigment ink layer or a metal thin film layer.

The pigment ink layer may be coated or printed with a solid pattern of a single color such as white, or may be printed with a repeating pattern such as stripes or a checkerboard. The pigment ink layer may be formed by coating or plate printing rather than digital printing. By not using digital printing, the pigment ink layer can be formed at low cost using general-purpose materials (pigments, etc.).

The pigment ink layer contains a resin component and a colorant such as a pigment. The colorant may contain not only normal colors such as white and black, but also metallic colors such as gold and silver. When the base layer 38 is formed in a white solid pattern, the base layer 38 becomes the white background of the digitally printed image layer 34 on which the image or the like is formed, thereby enhancing the aesthetic appearance of the image or the like. In addition, costs can be controlled compared to when only the digitally printed image layer 34 including the base is formed.

The pigment ink layer may form an image that complements the image of the digitally printed image layer 34. For example, a color that occupies a large area of the image formed on the surface of the can container 10 may be formed by the pigment ink layer, and the remaining parts may be formed by the digitally printed image layer 34. The pigment ink layer may also form an image of a common part that does not differ for each product of the can container 10.

For example, if the pattern or the like to be printed on the surface of the can container 10 has parts that are common to the product (e.g., the product name or basic design of the product) and parts that differ for each product (e.g., a two-dimensional code that differs for each product), the common parts may be formed using a pigment ink layer, and the parts that differ for each product may be formed using the digitally printed image layer 34. These methods allow for cost control compared to forming all the patterns or the like using only the digitally printed image layer 34.

The metal thin film layer may be a metal thin film formed by deposition or the like on one side of the resin film 36. For example, the metal thin film layer may be an aluminum deposition layer. When the base layer 38 is a metal thin film layer, the background of the digitally printed image layer 34 on which the pattern or the like is formed has a metallic luster, so that the pattern or the like can be given a luxurious feel.

The base layer 38 may be a single color or multiple colors. The base layer 38 may be formed of a single layer or multiple layers. The base layer 38 may also be a layer that combines a pigment ink layer and a metal thin film layer.

Figure 7 shows an example of the layer structure of a can container 10 in this embodiment. The can container 10 in Figure 7 has a resin film 70 provided on the outer peripheral surface side of the can body 20, and a printed label 30 is adhered to the can body 20 by an adhesive layer 40. The inner surface protective layer 60 may also be a resin film. As an example, the can container 10 may be a resin-coated can in which both sides of a metal can body 20 are coated with a resin film such as a polyester film, and a printed label 30 consisting of a resin film 32 and a digitally printed image layer 34 is adhered via an adhesive layer 40 to the resin-coated can.

According to the embodiment shown in FIG. 7, a resin-coated can can be used that does not require water during the molding process of the can body 20. Therefore, this embodiment can provide a can container 10 that has a low environmental impact.

Figure 8 shows an example of a flow of a manufacturing method of the can container 10 of this embodiment by wet molding. The can container 10 of this embodiment can be manufactured by performing the processes of S100 to S800 in Figure 8. For ease of explanation, the processes of S100 to S800 will be explained in order, but at least some of these processes may be performed in parallel, or each step may be interchanged as long as it does not deviate from the spirit of the present invention. Some steps may also be omitted.

First, in S100, wet molding is performed on the metal plate. Wet molding is a molding method that uses a lubricant when molding the can body 20. Next, each step of the wet molding will be explained using FIG. 9. FIG. 9 shows an example of a subflow of the wet molding in S100 in this embodiment. The wet molding in S100 includes steps S11 to S16.

In step S11, uncoiler processing is performed. Specifically, the coiled metal sheet that will become the material for the can body 20 is uncoiled and stretched. The material for the metal sheet may be, for example, aluminum or steel whose main component is iron.

Next, in S12, lubricating is performed. Specifically, a lubricant is applied to the metal plate stretched in S11. The lubricant functions as a lubricant and a coolant, and a known material is used.

Next, in S13, a cupping press is performed. Specifically, the metal plate to which the lubricant was applied in S12 is punched into a disk shape. Here, further drawing is performed to obtain a cup-shaped metal material.

Next, in S14, the body is made. Specifically, the cup-shaped metal material obtained in S13 is subjected to drawing and ironing to form a cylindrical can-shaped container with a constant thickness around the peripheral wall and a dome-shaped bottom. This forms the body 200 and bottom 300 of the can container 10.

Next, in S15, trimming is performed. Specifically, the tops of the can-shaped containers obtained in S14 are trimmed to evenness.

Next, in S16, the washer process is performed. Specifically, the can-shaped container obtained in S15 is washed to remove lubricants and other contaminants, and then dried. After S100, the process of S200 is performed.

In S200, the inner surface protective layer 60 is formed. For example, the inner surface of the can-shaped container may be coated with a transparent paint by spray painting. If the inner surface protective layer 60 is not provided (for example, the form shown in FIG. 2), the process of S200 may be omitted. After S200, the process of S300 is performed.

In S300, the printed label 30 is manufactured. Specifically, digital printing is performed on one side of the resin film 32 to form a digitally printed image layer 34. The resin film 32 may be the one described in FIG. 2. Digital printing refers to a printing method that does not use a plate and can be performed on demand. For example, digital printing may be inkjet printing or electrophotographic printing. As an example, the printed label 30 may be manufactured by printing and forming an image or the like on the resin film 32 with inkjet ink or toner (hereinafter also simply referred to as "toner, etc."), and then curing and/or drying the image or the like.

In electrophotographic printing, a laser beam method or an electron beam method may be used. In addition, powder toner or liquid toner may be used as the toner. From the viewpoint of preventing and reducing shrinkage of the resin film 32 etc. due to thermal transfer, it is preferable to use liquid toner, but this is not limited to this.

In order to improve the adhesion between the resin film 32 and the toner, etc., the resin film 32 may be subjected to a surface treatment before printing. As an example, the resin film may be subjected to a corona treatment or plasma treatment, etc., and/or a primer layer, etc. may be formed. Known toner, etc. may be used.

The resin film 32 may be printed multiple times to form a digitally printed image layer 34 made up of multiple layers. In this case, some of the multiple prints may not be digitally printed but may be plate-printed such as gravure printing, or all of them may be digitally printed.

In one embodiment, a further resin film 36 may be laminated on the digitally printed image layer 34. This results in the printed label 30 shown in Figures 5 and 6. In one embodiment, a transparent paint or the like may be applied, cured, and dried on the digitally printed image layer 34 to form a protective layer in place of the resin film 36.

In one embodiment, a base layer 38 may be further formed on the upper side (opposite the resin film 32) of the resin film 36 or the protective layer. This results in the printed label 30 shown in FIG. 6.

The base layer 38 may be a pigment ink layer formed by coating or printing a pigment ink. For example, the pigment ink layer may be formed by coating such as gravure coating, or by plate-type printing such as gravure printing. As an example, a pigment ink is applied to the outer peripheral surface of the can body 20 and dried to form a pigment ink layer on at least a portion of the surface of the printed label 30.

The base layer 38 may be a thin metal film layer formed on at least a portion of the surface of the printed label 30. For example, the thin metal film layer may be formed by vapor deposition of a metal such as aluminum. Alternatively, the thin metal film layer may be formed by attaching a metal foil such as aluminum foil.

The process of S300 does not have to be performed after S100-S200, but may be performed in parallel with or prior to S100-S200. Next, the process of S400 is performed.

In S400, the printed label 30 including the digitally printed image layer and resin film produced in S300 is attached to the can body 20 of the can-shaped container obtained in S200 (or S100). For example, an adhesive or a semi-cured film of an adhesive semi-cured may be placed between the outer peripheral surface of the can-shaped container and the printed label 30, and the printed label 30 may be adhered to the can. The adhesive may be appropriately selected in consideration of the adhesiveness between the adhesive surface of the printed label 30 (i.e., the surface opposite the resin film 32) and the can-shaped container. For example, the adhesive may be, but is not limited to, an acrylic resin adhesive, a polyurethane resin adhesive, a polyester resin adhesive, or an epoxy resin adhesive.

This forms an adhesive layer 40 between the can body 20 and the printed label 30 that form the can-shaped container. If a pigment ink layer or a metal thin film layer is formed on the surface of the printed label 30, adhesion may be performed so that the pigment ink layer or the metal thin film layer is positioned between the can body and the printed label. Next, processing of S500 is performed.

In S500, a varnish layer 50 is formed on the outer peripheral surface of the can-shaped container (i.e., the resin film 32). For example, a varnish composition may be applied to a part or the entire outer peripheral surface of the can-shaped container, and cured to form the varnish layer 50. The varnish composition may contain a resin component, wax, an organic solvent, and additives as necessary. The resin component may contain a cured thermosetting acrylic resin, a thermosetting epoxy resin, or a thermosetting polyester resin. Curing may be performed by heating, blowing air, ultraviolet light irradiation, electron beam irradiation, or a combination of these.

S500 (i.e., forming the varnish layer 50) may be performed during S300 (i.e., manufacturing the printed label 30). In this case, the varnish layer 50 may be formed in advance on one of both sides of the resin film 32 opposite the side on which the digitally printed image layer 34 is formed, prior to printing. Alternatively, the varnish layer 50 may be formed after printing.

Also, if the can container 10 does not include a varnish layer 50 (for example, the form shown in FIG. 2), processing in S500 may be omitted. Next, processing in S600 is performed.

Neck processing is performed in S600. Neck processing (also called necking) forms one end of the can-shaped container to form the lid portion 100 so that the lid can be later seamed. A reduced diameter portion may be formed during neck processing. Methods known in the can manufacturing field may be used for neck processing.

The necking may be performed between S100 and S400. The printed label 30 is attached to the can container 10 that has already been necked. In this case, the printed label 30 may be attached to at least the body portion 200.

By performing neck processing, a can container 10 having a lid portion 100, a body portion 200, and a bottom portion 300 is formed. Next, processing of S700 is performed.

In S700, the can container 10 is inspected. For example, the outer or inner surface of the can container 10 is inspected for dents, holes, scratches, stains, etc. For example, the can container 10 is inspected for sufficient clarity of the pattern, etc., and for printing misalignment, chipping, bleeding, etc. Inspection may be performed using an inspection device or visually by a human. Next, processing in S800 is performed.

In S800, the inspected can container 10 is filled with the contents. A can lid is attached to the can container 10 filled with the contents. Filling with the contents and attaching the can lid may be performed by a known method. For example, a can lid with a drinking spout may be placed on the can container 10, and the can lid may be fixed to the can container 10 by rolling and seaming.

Steps S100 to S200 may be performed at a can manufacturing plant. Step S300 may be performed at a label manufacturing plant. Steps S400 to S800 may be performed at a bottler. However, as mentioned above, step S500 may be performed at a label manufacturing plant along with step S300. If steps S400 and onwards are performed at a bottler, the can manufacturing plant stores the can containers without the printed label 30 attached.

In this case, even if the design or other changes are made, the bottler can affix the changed design or other changes to the can container, reducing the number of can containers that need to be discarded. In addition, because the designs or other changes are made using digital printing, design changes can be made more quickly and with greater freedom. In addition, there is no need to store many different types of printed can containers at the can manufacturing factory, which is advantageous in terms of storage costs and can meet the needs of small lots of many different types.

Note that steps S100 to S700 may be performed at the can factory, and step S800 may be performed at the bottler. The division of steps between the can factory and the bottler is not limited to this pattern.

Figure 10 shows an example of a flow of a manufacturing method by dry molding of the can container 10 of this embodiment. The can container 10 of this embodiment can be manufactured by the processes of S110 to S800 in Figure 10. For ease of explanation, the processes of S110 to S800 will be explained in order, but at least some of these processes may be performed in parallel, or the steps may be interchanged as long as it does not deviate from the spirit of the present invention. Explanations of steps S110 to S800 that are common to the steps in Figure 8 will be omitted.

First, in S110, dry molding is performed on the metal coil material. Dry molding is a molding method that does not use lubricants when molding the can body 20. This means that large amounts of water are not consumed for cleaning the lubricants, etc., and the environmental impact can be reduced. Next, each step of the dry molding will be explained using Figure 11.

Figure 11 shows an example of a subflow of dry molding in S110 in this embodiment. Dry molding in S100 includes steps S11, S120, S13, S14, and S15. Of these, the processes in S11, S13, S14, and S15 may be the same as the corresponding processes in the wet molding shown in Figure 9.

In dry molding, S120 is performed after S11. Next, in S120, a resin film is laminated onto the metal plate stretched in S11. For example, the resin film may be heat-pressed onto both sides or one side of the metal plate. When the resin film is laminated onto both sides of the metal plate, the shape is the same as that shown in FIG. 7, and the resin film on the inner side of the laminated resin film functions as the inner protective layer 60.

The resin film may be a thermoplastic resin, preferably a polyester film. A thermosetting resin may be used in place of a plastic resin in the resin film. For example, a thermosetting acrylic resin, a thermosetting epoxy resin, a thermosetting polyurethane resin, or a thermosetting polyester resin may be used. As an example of lamination, the method described in JP-A-2004-25640 may be used.

According to this embodiment, by applying a resin film to the can body, it is possible to provide appropriate slipperiness during can molding without using a lubricant. Since no lubricant is used in the flow of Figure 11, the washer process of S16 in Figure 9 can be omitted, but the washer may be run to remove dirt, etc.

If necessary, a lubricant may be applied after laminating the resin film. In this case, the washer process of S16 may be performed in the same manner as in FIG. 9.

The present invention has been described above using an embodiment, but the technical scope of the present invention is not limited to the scope described in the above embodiment. It is clear to those skilled in the art that various modifications and improvements can be made to the above embodiment. It is clear from the claims that forms with such modifications or improvements can also be included in the technical scope of the present invention.

The order of execution of each process, such as operations, procedures, steps, and stages, in the can bodies, can containers, and methods shown in the claims, specifications, and drawings is not specifically indicated as "before" or "prior to," and it should be noted that the processes can be performed in any order, unless the can bodies or can containers from a previous process are used in a later process. Even if the operational flow in the claims, specifications, and drawings is explained using "first," "next," etc. for convenience, it does not mean that it is necessary to perform the processes in this order.

REFERENCE SIGNS LIST 10 Can container 20 Can body 30 Printed label 32 Resin film 34 Digitally printed image layer 36 Resin film 38 Base layer 40 Adhesive layer 50 Varnish layer 60 Inner surface protective layer 70 Resin film 100 Lid 200 Body 300 Bottom 400 Pattern 500 Characters

Claims (8)

Cylindrical can body,
a digitally printed image layer covering at least a portion of an outer periphery of the can body;
A resin film that covers the can body and the digitally printed image layer; and
A varnish layer covering at least a portion of the resin film;
Equipped with
said digitally printed image layer being an electrophotographically printed image layer ;
The digitally printed image layer is an electrophotographically printed image layer using liquid toner.
Tin container. The resin film is a PET film.
The can container according to claim 1. Between the can body and the digitally printed image layer,
The can container according to claim 1 or 2, comprising a pigment ink layer. Between the can body and the digitally printed image layer,
A metal thin film layer is provided.
A can container according to any one of claims 1 to 3. Cylindrical can body,
a digitally printed image layer covering at least a portion of an outer periphery of the can body;
A resin film that covers the can body and the digitally printed image layer; and
A varnish layer covering at least a portion of the resin film;
Equipped with
A method for manufacturing a can container , wherein the digitally printed image layer is an electrophotographically printed image layer ,
manufacturing a printed label having the electrophotographically printed image layer formed on the resin film by electrophotographically printing a liquid toner on the resin film; and
A label attachment step of attaching a printed label including the digitally printed image layer and the resin film so as to cover at least a portion of the outer circumferential surface of the can body.
A method for manufacturing can containers. The ink layer forming step further comprises forming a pigment ink layer on at least a part of the surface of the printed label,
The labeling step is performed such that the pigment ink layer is positioned between the can body and the printed label.
The method for producing the can container according to claim 5 . The ink layer forming step includes:
A step of applying a pigment ink to the outer peripheral surface of the can body by gravure coating and drying the same.
The method for producing the can container according to claim 6. A metal thin film layer forming step is further provided for forming a metal thin film layer on at least a part of the surface of the printed label,
The labeling step is performed such that the metal thin film layer is positioned between the can body and the printed label.
The method for producing the can container according to claim 6.

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