JP2001114245A - Production of printed bottle-shaped can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a bottle-shaped can wherein a mouth neck part, a shoulder part and a body part are integrally molded so as to be capable of expanding the range of the printing design applied to the outer surface of a can to the shoulder part of the can without restricting the same to the cylindrical body part of the can by directly applying printing to the outer surface of the can in the same way as the case of a conventional two-piece can. SOLUTION: After a process punching a metal thin panel of which both surfaces are coated with a lubricant to mold the same into a cup shape and a process for further molding the cup-shaped molded object into a bottomed cylindrical can of which the body part is reduced in diameter and wall thickness, the lubricant is removed from at least the outer surface of the bottomed cylindrical can to apply printing to the outer surface of the cylindrical body part of the can and the lubricant is again applied to the bottomed cylindrical can to which printing is applied and the bottom part side of the can including the vicinity of the bottom part of the body part to which printing is applied is molded into a shoulder part and a mouth neck part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a bottle can having a body, a shoulder, a mouth and a neck integrally formed from a sheet metal, and more particularly to a method for manufacturing such a bottle can. The present invention relates to a method for producing a state in which printing is performed from the body to the shoulder on the outer surface.

[0002]

2. Description of the Related Art In the canning of various soft drinks and beers (beverage cans), can bodies are drawn from an aluminum or steel sheet by an appropriate method such as drawing and ironing or deep drawing (drawing / redrawing). Generally, two-piece cans in which the (side wall portion) and the can bottom (end wall portion) are integrally formed are used.
In the case of a piece can, the content of soft drinks, beer, etc. is added to the can body with a neck-in flange processed at the upper end opening of a thin-walled can body integrally molded from the can bottom with enhanced pressure resistance. After filling the can, the can is sealed by winding an easy open end (a lid plate with a simple opening) with a diameter smaller than the can body diameter on the flange at the upper end of the can body, and the easy opening of the easy open end is opened. The contents are taken out by doing.

On the other hand, various kinds of soft drinks have recently been
With the advent of polyethylene terephthalate resin integrally molded containers (PET bottles), a large number of products in PET bottles that can be resealed with screw caps have been produced. Although it is lighter in weight and can be resealed with a cap compared to the cans of such beverage cans, the rate of resource recovery and recycling is very low at present, With regard to metal cans having a high recycling rate and excellent light-shielding properties, gas-permeation resistance, and rapid cooling properties, it has been studied to improve the convenience by adding a function that can be resealed with a cap.

[0004] As a metal can that can be resealed by such a screw cap, a small-diameter mouth and neck, a shoulder having an inclined surface, and a large-diameter trunk are formed so as to have a shape similar to that of a PET bottle. Integrally molded, the bottom of the can opposite to the mouth and neck is sealed by winding and fixing a separate bottom lid, and a screw cap is screwed to the opened mouth and neck. Metal sheet thin bottle cans are available from Tokio Hei 10-50909
No. 5 discloses this as one of the embodiments.

[0005]

When a printed design such as a character or a decorative pattern is to be provided on the outer surface of a beverage container, the body of the PET bottle has a non-circular shape or an uneven portion. Printed or heat-shrinkable film because it is virtually impossible to print directly on the entire circumference of the bottle body or heat-bond a printed resin film because it is very thin. Is shrink-wrapped on the bottle body to give a print design.

[0006] On the other hand, in the above-mentioned metal bottle-shaped can, before neck-in processing is performed on the bottom side,
Since it has an opening of the same diameter as the body, it is possible to print directly on the can body or heat-bond a printed resin film as in the case of a conventional two-piece can, and by doing so, An appearance different from that of the PET bottle can be obtained, and the product can be differentiated.

However, when a heat-shrinkable film that has been printed, such as a PET bottle, is shrink-wrapped in the bottle body, the printed design can be provided not only on the body of the bottle but also on the shoulder. In a case where printing is directly performed on the outer surface of a bottle-shaped can, a printing device for a two-piece can body that has been conventionally used can print only on a cylindrical body, but has an inclined surface. Since the printing cannot be performed up to the shoulder, there is a problem that the range in which the print design can be provided is limited to the cylindrical body.

An object of the present invention is to solve the above-mentioned problems. More specifically, the present invention relates to a method for manufacturing a bottle-type can in which a mouth, a neck, a shoulder, and a body are integrally formed. 2
Printing directly on the outer surface of the can, as in the case of piece cans, so that the range of print design applied to the outer surface of the can can be extended not only to the cylindrical body but also to the shoulders Is the subject.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is characterized in that a small-diameter mouth-and-neck portion, a shoulder having an inclined surface, and a large-diameter trunk are integrally formed. In the method for manufacturing a bottle-shaped can in which the outer surface of the body is printed from the bottom and the bottom lid is fixed to the lower end of the body, a metal sheet with a lubricant applied to both sides is punched out to form a cup. After the step of molding into a cup-shaped, and the step of further molding the cup-shaped one into a bottomed cylindrical can with a thinner diameter and thinner body, then lubricate at least the outer surface of the bottomed cylindrical can. After removing the agent, printing on the outer surface of the cylindrical body, after applying the lubricant again to the bottomed cylindrical can that has been printed,
The bottom side of the can, including the vicinity of the bottom of the printed body,
It is characterized by being molded on the shoulder and the mouth and neck.

According to the method for producing a printed bottle can described above, the lubricant is removed at the stage of the bottomed cylindrical can in the process of forming a thin metal plate into a bottle, and the cylindrical body is removed. Since the outer surface is printed, it can be directly printed on the outer surface of the can in the same way as in the case of the conventional two-piece can, and in the subsequent process, the printed bottomed cylindrical can is lubricated. After applying the agent again, since the bottom side of the can is molded so that the vicinity of the bottom of the printed body becomes a part of the shoulder, the shoulder of the bottle shaped can (A part of the shoulder) is given a print design.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the method for producing a printed bottle can of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of a bottle-shaped can manufactured by the method of the present invention. The bottle-shaped can 1 has a dome having a circular arc-shaped vertical section extending upward from a large-diameter cylindrical body 2. A small-diameter cylindrical mouth-and-neck portion 4 is integrally formed via a shoulder 3 having a shape, and a lower end opening of the body portion 2 is hermetically sealed by tightly fastening a bottom lid 5. On the outer surface of part 2,
A desired print design (characters, decorative patterns, and the like) is applied so that a large part of the body 2 including the hatched shoulder 3 is in the print range.

FIG. 2 schematically shows a process for manufacturing the bottle-shaped can shown in FIG. 1. In the method of this embodiment, both sides of a thin metal plate are made amorphous. First, in the cup forming process, a blank formed by punching the coated metal sheet into a disk shape is drawn and formed into a cup shape by using the coated metal sheet coated with the lubricant coated with the thermoplastic resin coating layer Then, in the next can body forming step, the cup is subjected to redrawing at least once or more to form a bottomed cylindrical can having a small diameter and a thin body.

Next, in a lubricant removing step, at least the lubricant is removed from the outer surface of the can. In a trimming step, the opening end side of the can is trimmed to make the can have a predetermined length.
It is sent out for the same printing and painting process as in the case of conventional two-piece cans. In the printing and painting process, the desired design (characters, decorative patterns, etc.) is printed on the cylindrical body, and the top After applying the coat, the printing ink layer and the top coat layer are sufficiently dried in a drying step.

With respect to the bottomed cylindrical can having the printing (and the top coat) applied to the body in this manner, the lubricant is applied again in the lubricant re-application step, and then, in the top dome forming step, The bottom corner of the bottomed cylindrical can (bottom part and the body part near the bottom part) is preliminarily provided with a shoulder curved surface with an arc-shaped vertical section in a state that includes the printed part applied to the body part. After forming, the drawing is performed a plurality of times on the bottom side of the can to form the shoulder and the unopened mouth and neck.

Next, in a lubricant removing step, the can is heated to remove the lubricant and the thermoplastic resin coating layer is made amorphous. After opening the mouth and neck by trimming the closed end of the end, the opening end is formed into an annular curl portion by external winding, and a screw for cap screwing is formed on the cylindrical peripheral wall, and the screw is formed. A bead portion is formed below the portion.

Then, in a neck / flange forming step, neck-in processing and flange processing are sequentially performed on a lower end opening end of the body part opposite to the mouth and neck, and then a bottom cover winding step (not shown) is performed. In the above, the bottom cover of another member made of a sheet metal material is integrally fixed to the flange formed at the lower end opening of the body by the double seaming method using a seamer (can lid winder). Thus, a bottle-shaped can as shown in FIG. 1 is completed.

The method of manufacturing the bottle-shaped can of the present embodiment as described above will be described in more detail. The thin metal plate as a raw material is prepared by laminating a thermoplastic resin film such as a polyester resin or a polypropylene resin on both surfaces of an aluminum alloy plate in advance. Coated metal sheet having a thickness of 0.1 to 0.4 mm, for example, 300 mm having a thickness of 0.315 mm.
For a 4H191 aluminum alloy plate, a mixed resin of polybutylene terephthalate resin (PBT) and polyethylene terephthalate resin (PET) (PBT: PET =
60:40) with a thickness of 20 μm on the inner side,
A coated metal sheet laminated so as to have a thickness of 20 μm on the outer surface side is used.

The method of laminating the thermoplastic resin film on the thin metal plate includes not only the case where the thermoplastic resin film formed in advance as a film is directly thermally bonded to the metal surface of the thin metal plate, but also the case where the thermoplastic resin film melted from the T-die is used. When the resin is extruded onto a pre-heated thin metal plate and directly bonded, and a thermoplastic resin film formed in advance as a film is bonded through an adhesive primer layer or a curable adhesive layer or a thermoplastic resin layer having good thermal adhesiveness. In some cases, it is thermally bonded to the metal surface of a thin metal plate. In the laminating step, it is preferable from the viewpoint of workability and adhesiveness that the thermoplastic resin film that has been thermally bonded is amorphous once cooled (for example, by passing it through water) and then rapidly cooled. .

With respect to the coated metal sheet having the thermoplastic resin film layers formed on both surfaces, normal butyl stearate, liquid paraffin, petrolatum, polyethylene wax, edible Oil, hydrogenated edible oil, palm oil, synthetic paraffin, dioctyl sebacate, etc. is applied as one or more kinds of lubricants, and the coated metal sheet coated with the lubricant is used as a material in a cup forming process. In this example, this is punched into a blank for each can and formed into a cup shape by drawing. For example, a blank punched into a disk having a diameter of 170 mm has a height of 48.3 mm and an outer diameter of 100 mm
Is drawn into a cup shape.

In the can body forming step, the cup thus formed is further subjected to bending and stretching in one of two redrawing steps, and thereafter, is subjected to ironing. After forming into a bottomed cylindrical can with a small diameter and a thin body part, the lubricant is removed from at least the outer surface of the bottomed cylindrical can. The height of the can (the length in the cylindrical axis direction) is made uniform by trimming the open end side. For the formation of this bottomed cylindrical can, for example, a cup having a height of 48.3 mm and an outer diameter of 100 mm is formed into a bottomed cylindrical can having a height of 171.5 mm or more and an outer diameter of 65.9 mm. From above, trimming is performed so that the height is adjusted to 171.5 mm.

The lubricant removing step of removing the lubricant from the bottomed cylindrical can is performed in order to remove the lubricant such as normal butyl stearate, liquid paraffin, and synthetic paraffin applied to the inner and outer surfaces of the can. For example, a well-known degreasing agent and water or hot water are sprayed on the inner and outer surfaces of the can to wash the lubricant to remove the lubricant or to remove the can from 200 to
The lubricant is volatilized by heating to a high temperature of about 300 ° C. (preferably 255 to 300 ° C.). In addition,
It is not necessary to remove the lubricant adhering to the inner surface of the can at this stage.However, the lubricant adhering to the outer surface of the can must be surely removed from the printing and painting process. It is necessary to keep.

When a cleaning method is used to remove the lubricant, a can washer used in the degreasing / cleaning step of the squeezing and ironing can may be used, and when the lubricant is volatilized, an opening may be used. Hot air may be blown while the can is placed on a net conveyor and transported with the side facing down. If the thermoplastic resin film layer is to be made amorphous again if necessary in the lubricant removing step or the drying step after printing / painting, the temperature of the hot air is adjusted to the melting point of the thermoplastic resin. The temperature may be set to a higher temperature, and after blowing hot air, cold air (20 ° C. or less, preferably 15 ° C. or less) may be further blown.

Although not shown in the printing / painting process, a two-piece can (with a cover plate fixed thereto) is conventionally not illustrated in the printing and painting process for a bottomed cylindrical can having at least the outer surface side lubricant removed and having a uniform height. Appropriate apparatus (for example, Japanese Patent Application Laid-Open No. SHO 48-48) used for continuously printing and coating the outer surface of the cylindrical body while transporting the front can body by a mandrel.
-58905, JP-A-54-92810,
JP-A-57-170758, JP-A-57-178
No. 754, etc.), printing (and top coating) is performed on the outer surface of the cylindrical body in exactly the same state as the conventional two-piece can.

The portion near the bottom of the body of the bottomed cylindrical can is a portion that is re-formed into the shoulder by drawing in the subsequent top dome forming step, and is re-formed into the shoulder. Sometimes, the closer to the bottom, the shorter the length in the circumferential direction, and the printing design is also affected, so the width in the circumferential direction is narrower, closer to the bottom. It is necessary to design the vicinity (the shoulder portion) in consideration of this.

That is, when the portion near the bottom of the body of the bottomed cylindrical can is re-formed into the shoulder through the top dome forming step, a vertically long sentence is formed from the center of the shoulder toward the body. There is almost no problem except for designs that clearly show that the thickness of the characters and the width of the pattern are different between the mouth and neck side and the torso side, such as a repeated pattern in the vertical direction and the shoulder side. For the part near the mouth and neck from the center of the part,
Due to the anisotropy of the metal sheet that forms the can body, the size of the characters and patterns is not uniform even for horizontal writing and repeated patterns in the circumferential direction. Simple shade pattern, simple geometric pattern, simple pattern with multiple clouds floating in the blue sky, and a small number of characters (1-2 characters)
It is preferable to make a print design of words and the like.

For this reason, regarding the print design to be applied to the portion near the bottom of the torso, the portion near the torso of the shoulder portion has a sentence or pattern other than a vertically long sentence or a vertically repeated pattern. By selecting the print design of the above, it is possible to prevent the sentences and patterns of the shoulder curved surface from being distorted. By selecting a print design such as a pattern or a word with a small number of characters, it is possible to make the distortion of the pattern or the character applied to the relevant portion inconspicuous, and as a result, the shoulder after being formed by the top dome forming process. The print design of the part and the torso can be uniform.

To a bottomed cylindrical can that has been printed and painted and dried in a drying device such as an oven, a liquid lubricant such as normal butyl stearate, liquid paraffin, or synthetic paraffin is added to the can. In the top dome forming process, first, the can bottom corner portion (bottom portion) of a cylindrical can with a bottom is used after a spray device or a lubricant coating device (waxer) such as a rotary coating device made of felt is applied again on the outer peripheral surface. And the body near the bottom) is preformed into a shoulder curved surface having an arc-shaped vertical section, and as shown in FIG. 3 with the can bottom side up,
The flat can bottom surrounded by the can bottom corner preformed on the shoulder curved surface is pressed with a wrinkle press tool (die and pusher) equipped with a curved surface that is in close contact with the shoulder curved surface, and the body is punched. After drawing into a bottomed cylindrical shape with a smaller diameter than the part, the bottom side of the newly drawn bottomed cylindrical part is approximated to the cross-sectional arc of the virtual curved surface following the preformed shoulder curved surface Using a wrinkle holding tool (die and pusher) having a tapered surface as described above, the sheet is drawn into a smaller-diameter bottomed cylindrical shape by punching.

Then, by repeating such drawing again, the diameter of the bottomed cylindrical portion is reduced until it becomes substantially the same as the diameter of the mouth and neck portion. A plurality of tapered surfaces of the shoulder formed following the initial shoulder curved surface are stretched by a pair of forming tools (die and pusher) having a virtual curved surface shape extending from the shoulder curved surface, so that continuous smoothness is obtained. After reshaping into a curved surface (reform), although not shown in FIG. 3, the mouth and neck formed into a bottomed cylindrical shape is subjected to mouth drawing twice.

In the top dome forming step, first,
For a cylindrical can with a bottom, the vicinity of the can bottom of the thinned body is preformed into a curved shoulder portion, and then the top dome is formed so that the preformed portion becomes a part of the shoulder (shoulder). In order to prevent wrinkles from being formed in the preformed part during the formation of the top dome, a cylindrical can with a bottom is formed from a cup. In the can body forming step, the thickness of the preformed body portion (sidewall portion near the can bottom) is 60% or more of the thickness of the can bottom (substantially the same as the thickness of the thin metal sheet before processing). It is preferable to keep the thickness.

Next, prior to screw-curl forming of the mouth-neck formed by mouth drawing, a lubricant applied by a lubricant applying device (waxer) before forming the top dome is heated at a high temperature. A thermoplastic resin film (for example, a mixed resin film of polybutylene terephthalate resin and polyethylene terephthalate resin) covering both sides of the can at the same time as being volatilized and removed by heating
, And then rapidly cooled to make the thermoplastic resin film layer amorphous, thereby improving the adhesion between the resin film and the aluminum alloy plate.

With respect to the amorphization of the thermoplastic resin film layer, the thermoplastic resin film layer, which had been formed in an amorphous state on the coated thin metal sheet from the beginning, was formed as a result of the subsequent molding. The thermoplastic resin coating layer is crystallized by stretching (that is, the initially amorphous thermoplastic resin coating layer is crystallized by successive stretching by cup molding, can body molding, and top dome molding). Even if it is made amorphous again in the lubricant removal process and drying process in the middle, the thermoplastic resin coating layer in the top dome molded part is crystallized by stretching by this molding) Before the screw / curl forming step of performing severe processing, the film is made amorphous again to reinforce the adhesion to the aluminum alloy plate.

The amorphization before the screw / curl forming step may be performed by a separate heating / quenching apparatus. However, in the lubricant removing step immediately before the screw / curl forming step, the can is removed. When the lubricant is heated to a high temperature to vaporize the lubricant at the same time, the lubricant can be efficiently amorphousized without providing a dedicated device for amorphousization.

In a screw / curl forming step, first, a small diameter at the upper end of the mouth and neck portion is applied to a can whose body has been subjected to printing (and top coat) and the thermoplastic resin film layer of the protective film has been made amorphous again. After opening the mouth and neck portion by trimming the portion, the opened mouth and neck portion are connected to the outer winding curl portion 11, the inclined wall 12, the screw forming portion 13, the bead portion as shown in FIG. 14 and a small-diameter cylindrical portion 15.

That is, after trimming and opening the small diameter portion at the upper end of the mouth and neck, the opening edge is slightly pre-curled outward, and then a mold having a curved surface having an arc-shaped cross section at the upper edge is formed. With the curl forming punch pressed down from above while inserted inside the mouth and neck, an outer curl is formed at the opening edge of the upper end of the mouth and neck, and the vertical section of the lower inclined wall is outwardly formed. It is formed into a curved surface that becomes an arc shape that swells into a circle.

Then, the cylindrical peripheral wall following the inclined wall below the curl portion is formed into a thread forming portion. In this case, a method of forming a screw thread and a screw valley is to form a female mold inside the mouth and neck. There is a method of molding by inserting and pressing the roll from the outside, a method of forming by pressing the roll from the inside of the mouth and neck, etc.After forming the screw by an appropriate method, the lower part of the screw forming part By pressing the roll from the outside under the width and leaving it as a small-diameter cylinder,
The lower part of the screw forming part is formed into an annular bead part.

When a metal pill fur proof cap is attached to the mouth and neck by a capper, the roller of the capper enters the small-diameter tube portion and the lower end wall of the cap. The lower end wall of the cap is pressed against the lower side wall of the bead (lower step) by deforming the lower end of the band below the perforation for breaking, so that the cap is pill fur proof (opened) on the mouth and neck. In such a case, the perforation is broken so that the fact can be visually recognized.)

In the neck / flange forming step, a neck-in process and a flange process are performed on the lower end opening end of the body opposite to the mouth-neck portion in the can whose neck and neck portion has been formed as described above. After successively applying, in the bottom lid winding step, the bottom lid of another member is double-tightened and fixed to the flange formed at the lower end opening of the can by a seamer (can lid winding machine). It becomes a bottle type can that can be filled with the contents.
Using a bottom lid having a thickness of 0.285 mm and a diameter of 62.6 mm made of an aluminum alloy (5182-H39) obtained by heat-sealing a mixed resin film of a polybutylene terephthalate resin and a polyethylene terephthalate resin having a thickness of mm. I have.

According to the method for manufacturing a printed bottle can of the present embodiment as described above, the lubricant is removed at the stage of the bottomed cylindrical can in the middle of molding to remove the outer surface of the cylindrical body. Because it is printed on the can, it can be printed directly on the outer surface of the can in exactly the same state as the conventional two-piece can, and the lubricant is applied again to the printed bottomed cylindrical can Then, in the subsequent top dome forming step, first, as shown in FIG. 3, the can bottom corner portion (bottom portion and body portion near the bottom portion) of the bottomed cylindrical can is changed to a printing range indicated by oblique lines. By preforming the shoulder curved surface in such a state as to include, since the bottom side of the can is formed so that the vicinity of the bottom of the trunk included in the printing range indicated by oblique lines becomes a part of the shoulder Extend the range of print design to the shoulders of bottle-shaped cans. Can.

In this embodiment, since the protective film covering the metal surface of the thin metal plate is a thermoplastic resin film layer, in the screw / curl forming step after removing the lubricant, the thermoplastic resin film layer is formed. Acts as a lubricant and does not easily peel off the protective coating by stretching or bending following the elongation or bending of the metal sheet. Since the thermoplastic resin film layer is made amorphous again in the lubricant removing step to improve the adhesion between the thermoplastic resin film and the metal plate, the protective coating ( The peeling of the thermoplastic resin film layer) can be reliably prevented, and as a result, the coating state of the protective coating can be maintained well until the completion of the molding of the can. Sufficiently it can provide corrosion resistance against the can having a rear painted hard portion on the inner surface, such as a shoulder portion that neck and abruptly diameter threaded.

Further, in this embodiment, in order to form the shoulder portion and the mouth and neck portion (not open), the can bottom corner portion of the can is preformed into a curved shoulder portion, and then the bottom portion is formed into a bottomed cylindrical shape. Forming and repeating drawing to the bottom formed into a cylindrical shape with a bottom using a wrinkle holding tool that has a tapered surface with a linear cross-sectional shape approximating the cross-sectional arc of a virtual curved surface following the preformed shoulder curved surface In order to form a small-diameter mouth and neck (not open) with, and then to extend the multiple tapered surfaces of the shoulder formed to approximate the curved surface into a continuous smooth curved surface, and re-mold it, The shoulder portion can be formed into a smooth and beautiful dome-shaped curved surface without leaving the edge.

Although one embodiment of the method for producing a printed bottle can of the present invention has been described above, the present invention is not limited to the above-described embodiment. Not only the aluminum alloy plate as shown in the above embodiment, but also ultra-thin tin-plated steel plate, nickel-plated steel plate, electrolytic chromium which has been subjected to various metal plating and surface treatments such as chemical conversion treatment used for can making It is also possible to use a surface-treated steel sheet such as an acid-treated steel sheet or a galvanized steel sheet.

The thermoplastic resin covering both surfaces of the metal sheet is also an olefin resin such as polyethylene, polypropylene, ethylene-propylene copolymer, modified olefin, polyethylene terephthalate, polybutylene terephthalate, ethylene terephthalate / isophthalate copolymer. Polyesters such as polymers, nylons, and mixed resins of two or more kinds of these resins can be used. Further, a thin metal sheet not coated with a synthetic resin film such as a thermoplastic resin film is used as a material for cans. It is also possible to carry out the coating after the molding by coating the metal surface with a synthetic resin film.

When a thin metal sheet coated with a thermoplastic resin film layer is used as a material, from the viewpoint of adhesiveness and workability, the thermoplastic resin film layer is made of an amorphous material as described in the above embodiment. It is preferable to perform molding such as cup molding, top dome molding and screw / curl molding after
It is also possible to carry out the molding process by performing a molding process in a state where the biaxially oriented crystals remain on the upper layer side of the thermoplastic resin coating layer without becoming amorphous.

Although a synthetic resin film such as a thermoplastic resin film layer covering both surfaces of the metal thin plate is not shown in the above embodiment, the synthetic resin film on the outer surface side of the can includes a metal thin plate. In order to conceal the metallic color, pigments and dyes such as titanium dioxide, calcium carbonate, alumina and aluminum powder can be mixed. However, since the moldability deteriorates when the amount of the pigment or the like is increased, it is preferable that the amount of the pigment or the like is limited to a small amount and the printing is performed with an ink containing a white pigment.

The molding of the cup into a bottomed cylindrical can is performed by the molding method described in the above embodiment,
That is, the thickness of the can body wall is made thinner than the thickness of the bottom portion by performing at least one thinning process for bending and elongating at the time of the redrawing process, and then performing at least one ironing process after the redrawing process. When molding a bottomed cylindrical can from as little metal sheet as possible,
Molding can be performed with little damage to the thermoplastic resin coated on the metal sheet, but it is not necessarily limited to such a molding method, and drawing, ironing, drawing / ironing, redrawing, It is also possible to perform molding by an appropriate number of times by selectively combining one or two or more appropriate molding methods such as bending and stretching. In addition,
If it is sufficient to extend the range of the print design to less than half of the shoulder, when forming a cylindrical can with a bottom, the lower end of the trunk is curved so that the can bottom corner of the can after printing It is possible to omit the step of preforming the portion into a curved surface having an arcuate vertical section.

Also, regarding the shape of the shoulder and the molding method,
The present invention is not limited to the case where the entire shoulder portion is formed into a smooth curved surface without forming marks as shown in the above embodiment, but may be formed in an appropriate shape (for example, a step portion is formed on the shoulder portion) by an appropriate molding method. The shape of the mouth and neck formed in the screw / curl forming step can be changed to a specific shape as shown in FIG. 5 (A). The present invention is not limited to this, and the shape can be changed to an appropriate shape as long as the curled portion and the screw portion are formed.

Further, the present invention is not limited to the case where a curled portion or a threaded portion is directly formed on the mouth and neck, and for example, as shown in FIG. It is also feasible to extrapolate and fix the cylindrical body with a synthetic resin thread on the mouth and neck as shown in FIG. 5 (B). Needless to say, the present invention is not limited to such a specific structure.

The specific structure shown in FIG. 5B will be described. A cap is screwed onto a cylindrical body 20 previously formed of a resin such as polypropylene, polyethylene or polyester by an injection molding method or the like. , A holding ring 22 for holding the can in the filling process of the contents, an inner recess 23 for preventing the relative rotation between the mouth and neck 4 and the cylindrical body 20, and the like. After the cylindrical body 20 is extrapolated to the mouth and neck 4 which has been formed and the upper end is opened by trimming, the opening edge of the mouth and neck 4 is pre-curled considerably outward and then curled from above. By pushing down the punch and curling it outward, the tip of the curled portion 17 bites into the outer peripheral surface of the upper end of the tubular body 20 and the upper end of the tubular body 20 is fixed. Apply hydraulic or elastic pressure from inside to On the inner surface side recess 23 of the shaped body 20 by overhang the side wall of the neck 4 of the corresponding position protrusion 18
Is formed, the tubular body 20 is fixed so as not to rotate with respect to the mouth and neck 4.

[0050]

According to the method for producing a printed bottle can of the present invention as described above, printing can be performed directly on the outer surface of the can in exactly the same state as in the case of the conventional two-piece can. Moreover, the range of the print design (printing range) applied to the outer surface of the can can be extended not only to the cylindrical body but also to the shoulder.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view showing an example of a printed bottle can manufactured by the method of the present invention.

FIG. 2 is an explanatory side view showing a manufacturing process for manufacturing the bottle can shown in FIG. 1;

FIG. 3 is a cross-sectional explanatory view showing a molding state of a mouth, a neck, and a shoulder in a top dome molding step in a manufacturing step of the bottle-shaped can shown in FIG. 2;

FIG. 4 is an explanatory side view showing a printing range of the can at each stage in a top dome forming process of the bottle can shown in FIG. 3;

FIG. 5 is a partial cross-sectional side view showing the mouth and neck of the bottle-shaped can shown in FIG. 1 with respect to the mouth and neck of the bottle-shaped can manufactured by the method of the present invention, and (B) a bottle-shaped can. FIG. 6 is a vertical cross-sectional view showing another example of the mouth and neck portion of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bottle type can 2 Body 3 Shoulder 4 Mouth and neck 5 Bottom lid

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B65D 1/02 B65D 1/00 C

Claims (5)

[Claims] 1. A small-diameter mouth-and-neck portion, a shoulder having an inclined surface, and a large-diameter torso are integrally formed, printing is performed on the outer surface of the torso from the shoulder, and a bottom is formed at a lower end of the torso. In a method for manufacturing a bottle type can to which a lid is fixed, a step of punching a thin metal sheet coated with a lubricant on both sides and forming it into a cup shape, and further forming the cup shape into a body with a small diameter. After the step of molding into a thinned bottomed cylindrical can, after removing the lubricant from at least the outer surface of the bottomed cylindrical can,
After printing on the outer surface of the cylindrical body, the lubricant is again applied to the printed bottomed cylindrical can, and then the bottom of the can including the vicinity of the bottom of the printed body. A method for producing a printed bottle can, characterized in that the sides are molded into a shoulder and a mouth and neck. 2. In the step of molding the bottom side of a cylindrical can with a bottom into a shoulder and a mouth and neck, a can bottom corner of the can is preformed into an arcuate shoulder curved surface with a vertical cross section, A cross section of a virtual curved surface following the preformed shoulder curved surface after drawing the bottom of the can into a cylindrical shape having a smaller diameter than the body portion while the shoulder curved surface of the can bottom corner portion is being wrinkled. Using a wrinkle holding tool having a tapered surface with a cross-section linear shape similar to an arc, the bottomed cylindrical portion drawn from the bottom of the can is wrinkled at the bottom corner by the tapered surface of the tool. Draw-formed into a small-diameter, bottomed cylinder, repeat such drawing until the diameter of the bottomed cylinder is approximately the same as the diameter of the mouth and neck, and then repeat the drawing to form a curved surface The multiple tapered surfaces of the shoulder formed in approx. The method for producing a printed bottle can according to claim 1, wherein the preform is stretched to a smooth curved surface and reshaped. 3. The printed bottle mold according to claim 1, wherein the bottomed cylindrical can is formed from a sheet metal having a protective coating including at least a thermoplastic resin layer on both surfaces. How to make cans. 4. A curled portion and a screw portion are formed in the mouth and neck after a step of forming the bottom side of the cylindrical can with a bottom into a shoulder and a mouth and neck. 4. The method for producing a printed bottle-shaped can according to any one of items 1 to 3. 5. After passing through a step of forming the bottom side of a bottomed cylindrical can into a shoulder and a mouth and neck, a cylindrical body with a thread made of synthetic resin is externally fixed to the mouth and neck. The method for producing a printed bottle can according to any one of claims 1 to 3, wherein