JP2002263745A - Bottle-type can manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bottle-type can manufacturing method capable of preventing generation of wrinkles on a shoulder part, preventing any stepped shape from being formed on the shoulder part, and forming the shoulder part of a smooth and beautifully inclined surface without any forming trace left behind. SOLUTION: In a can integrated in a bottomed cylindrical shape, a bottom cylindrical part 42 of small diameter and a curved surface 31 of a lower part of the shoulder part are formed on the can bottom side in one forming step, and in the next forming step, the bottom part of the bottomed cylindrical part is re-drawn into a bottomed cylindrical shape of smaller diameter by a punch 16 while performing holddown of a bottom corner part of the bottomed cylindrical part drawn from the can bottom in the previous step by using a pusher 15 for holddown of predetermined shape and a drawing die 14 with each tapered surface of the pusher and the die. This re-drawing operation is repeated as necessary until the diameter of the bottomed cylindrical part becomes substantially same as the diameter of a predetermined neck part. Inclined surfaces 32... of the shoulder part re-drawn approximate to the curved surface are pressed and extended into a continuous and smooth curved surface from a curved surface 1 below the shoulder part for re-forming.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for manufacturing
A method for manufacturing a bottle can having a body, a shoulder, a mouth and a neck integrally molded from a 0.4 mm sheet metal,
In particular, in the production of such a bottle-type can, the inclined shoulder portion and the small-diameter cylindrical mouth and neck portion are integrally formed by processing the can bottom side of a can having a bottomed cylindrical shape. The present invention relates to a molding method for forming a smooth shoulder with a smooth and beautiful inclined surface (dome-shaped curved surface or tapered surface) without wrinkles or molding marks.

[0002]

2. Description of the Related Art For canning of various soft drinks and beers (beverage cans), a body (side wall) and a bottom (end wall) are integrally formed by squeezing and ironing a thin metal plate of aluminum or steel. In general, such a DI can is formed by integrally forming a bottom part having a pressure-resistant shape and a body part thinned by drawing and ironing, and an upper end opening part of the body part. After filling the contents such as soft drink and beer into the can body with neck-in processing, it is wrapped with an easy open end (lid plate with a simple opening) smaller in diameter than the body. It is shipped as a beverage can in a sealed state.

[0003] Further, a surface-treated steel sheet coated on both sides with a thermoplastic resin film is subjected to drawing and bending and stretching (re-drawing is performed) so that the body is thinner than the bottom. For the bottomed cylindrical can
A beverage can having the same neck-in processing as a DI can has been put to practical use.

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. Compared to such cans of beverage cans, they have the convenience of being resealed with a cap, but the rate of resource recovery and recycling is currently low, so cans with a high resource recycling rate About the container,
It has been studied to improve convenience by adding a function that can be resealed with a cap.

For the bottle type DI can for that purpose, that is, a DI can having a mouth and a neck portion to be screwed with a screw cap,
Japanese Unexamined Patent Publication No. 10-509095 discloses a type in which the mouth and neck are integrally formed with a lid plate to be wound around the upper end opening of the DI can, or a step-down diameter of the upper end opening side of the DI can by neck-in processing. And the type which integrated the mouth and neck by DI
For each type of bottle-type can, such as a type in which the bottom of the can is molded into the shoulder and mouth and neck, and the bottom lid is wrapped around the can opening end opposite to the shoulder and mouth and neck The structure and manufacturing method are disclosed.

Further, a bottle can of a type in which the bottom of a DI can is molded into a shoulder portion and a mouth and neck portion is disclosed in Japanese Patent Application Laid-Open No. 58-47.
No. 520 discloses that, when a DI can is formed by drawing and ironing, the bottom of the can is flattened by a final stroke of a punch in the drawing and ironing, and a flat shoulder portion and a cylindrical mouth-neck portion are formed by redrawing with a die. It is disclosed that the DI can is formed by drawing and ironing.
It is disclosed that the bottom of the can is pressed to form a frustoconical shoulder and a cylindrical mouth and neck.

[0007]

Incidentally, the bottle type cans made of DI cans as described above are not limited to DI cans, but include bent cans and ironed bottomed cans, and are wound around the opening at the upper end of the can. In the type that the mouth and neck are integrally formed with the lid plate to be fastened, there is no need to change the shape of the can body from the conventional can. However, there is a problem that dust and debris easily accumulate in the concave portion inside the tightened portion because the canned portion has the winded portion of the lid plate at the top of the can, and the rolled portion itself protrudes and the appearance is bad. .

Further, in the type in which the mouth and neck portion is integrally formed by gradually reducing the diameter of the upper end opening side of the can by neck-in processing, the portion whose diameter is reduced to the mouth and neck portion by neck-in processing is already used. Even if it is a part that has been thinned by drawing and ironing or drawing and bending and stretching, and this part has been stretched to be thicker than the body wall below it, the amount of one drawing Because it is not possible to reduce the diameter at a time by increasing the size, it is necessary to reduce the cap to reduce the material cost and to reduce the diameter of the mouth and neck larger than the outer diameter of the torso accordingly Requires a multi-stage necking operation.

That is, for example, in the case of beverage cans such as beer, the can body diameter that is often used is 66 mm (211 diameter), and the neck and neck of such a can can be necked in to 25.4 mm in diameter. Since 20 to 30 necking steps are required, a large number of molding machines are required for necking, which increases equipment costs and decreases quality and productivity due to an increase in the number of steps. Is concerned.

On the other hand, in the type in which the bottom of the can is formed into the shoulder and the mouth and neck, a part of the shoulder and the bottom of the can formed in the mouth and neck are hardly formed when the can is formed. Since it is a part that is not affected by processing, there is no work hardening and the thickness is almost the same as the original blank thickness, so the upper part of the body of the can is neck-in processed and the mouth and neck part is formed as described above As compared with the case where the diameter is reduced, the diameter can be reduced one time and the diameter can be largely reduced in one step, and the number of steps required for forming the mouth and neck can be greatly reduced.

However, although it is possible to increase the amount of drawing at one time as compared with the case of neck-in processing, even if the drawing amount is slightly different due to the difference in material, the drawing ratio (the diameter reduction ratio by one drawing) ) Has a limit. For example, in the case of a beverage can made of a thin metal plate such as a can for beer, a flat bottom of a cylindrical DI can having a bottom (diameter of 66 mm) and a small cylindrical mouth and neck (diameter of 25 mm) can be used. (0.4 mm), it is necessary to repeat the drawing step three to four times because the drawing ratio at one time is as small as about 1.5.

Regarding this point, Japanese Patent Application Laid-Open No. 58-47 mentioned above
No. 520 discloses a method of forming the mouth and neck by re-drawing the bottom of the can with a punch and a die at the final stroke during molding of a DI can.
Japanese Patent Application Laid-Open No. 62233 discloses a method of forming a shoulder and a mouth and neck by pressing a can bottom of a DI can.
Unless a metal plate (approximately 1.5 mm) is used as a material, wrinkles will be generated by increasing the drawing ratio at one time, and shoulders and mouth and neck with the same shape as a normal PET bottle for beverages will be generated. It is not possible to form a part.

Therefore, as described above, when the squeezing step is repeated three to four times on the flat can bottom of the DI can to form a shoulder and a mouth and neck similar to those of a normal PET bottle for beverages. Since it is necessary to suppress wrinkles with a tool in each drawing step, a ring-shaped and step-shaped stepped portion (for example, the above-mentioned Japanese Patent Application Laid-Open No. In FIG. 28 and FIG.
2) is formed, and even if it is re-formed into a smooth inclined surface by press working, the stair-shaped portion remains as a ring-shaped forming mark. However, the appearance is not good.

Regarding the problem of the appearance of the shoulder,
Although it does not have a significant effect on the function, it is an important issue for the product to be sold, and beverage manufacturers always demand a design that expresses the product image in containers and makes it more motivating to purchase Therefore, making the shape of the shoulder from the mouth and neck to the can body into a smooth and beautiful dome shape is an important point in design, and it is strongly desired to eliminate the above-mentioned molding traces. ing.

According to Japanese Patent Publication No. 10-509095, a cup drawn from a blank is subjected to a plurality of drawing operations (preferably three times) on the bottom (end wall) of the cup, as shown in FIGS. The above procedure is repeated to form a small-diameter cylindrical neck and neck portion, and then the bottom (end wall) neck and neck portion is bulged into a shoulder dome shape. A method of forming a can body downward from the dome shape is shown. In such a method, when forming the can body, the bottom (end) is formed as the material moves from the side wall of the cup to the can body. The material of the mouth and neck formed in the wall) will be drawn into the can body part through the shoulder.

Therefore, the cylindrical shape of the mouth and neck formed on the bottom (end wall) cannot be maintained in the original shape, and the vertical wall of the cylinder of the mouth and neck becomes a tapered wall of a truncated cone. A predetermined screw thread cannot be formed in the screw molding for resealing, and there is a possibility that a problem that sealing performance is deteriorated may occur. The problem arises that the cervix and shoulders must be reshaped so that the part rises as a vertical wall.

An object of the present invention is to solve the above-mentioned problems. Specifically, the present invention has a thickness of 0.1 to 0.4.
For a cylindrical can with a bottom that is integrally formed so that the body is thinner than the bottom from a thin metal plate of mm, by further processing the bottom of the can, the inclined shoulder and small-diameter cylindrical In the method for manufacturing a bottle-shaped can in which the mouth and neck are integrally formed, wrinkles are generated on the shoulder even if drawing is repeated a plurality of times to reduce the diameter of the mouth and neck to a predetermined diameter. It is an object of the present invention to form a smooth and beautiful sloped shoulder without leaving a trace on molding without forming a staircase shape on the shoulder.

[0018]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is to integrally form a thin metal plate having a thickness of 0.1 to 0.4 mm so that the body is thinner than the bottom. In a method of manufacturing a bottle-shaped can, which has been formed such that a sloped shoulder portion and a small-diameter cylindrical mouth and neck portion are integrally formed by further processing the formed bottomed cylindrical can to the bottom side of the can. For a can that is integrally molded into a bottomed cylindrical shape, a curved surface forming pusher having the same convex curved surface as the lower curved surface of the shoulder of the bottle-shaped can to be molded on the outer surface of the tip, and the curved surface at the lower portion of the shoulder Using a drawing die having a concave curved surface corresponding to the inner surface of the tip portion, and a drawing punch having a smaller diameter than the body of the can, while pressing the can bottom corner portion of the can with a pusher and a die,
The can bottom is formed into a cylindrical shape with a smaller diameter than the body using a punch, so that a small-diameter bottomed cylindrical portion and a curved surface below the shoulder below it can be formed on the can bottom once. Formed.

In the case of manufacturing a bottle-shaped can having a dome-shaped curved surface at the shoulder, the following molding step approximates a vertical section circular arc of a virtual curved surface following the curved surface at the lower part of the shoulder. A wrinkle-pressing pusher having a tapered surface with a vertical cross-sectional linear shape on the outer surface of the tip, a drawing die having a tapered surface with a large outer diameter on the inner surface of the tip at the same inclination as the taper surface of the pusher, and in the previous step, Using a drawing punch with a smaller diameter than the drawing punch used, sandwich the bottom corner of the bottomed cylindrical part drawn and formed from the bottom of the can in the previous step with a pusher and each tapered surface of the die to suppress wrinkles Meanwhile, the bottom of the bottomed cylindrical portion is redrawn by a punch into a smaller-diameter bottomed cylindrical shape, and the diameter of the bottomed cylindrical portion becomes approximately the same as the predetermined mouth-neck diameter in such redrawing. Repeat as necessary until The inclined surface of the shoulder formed by approximating a curved surface by drawing, reshaping extended press into a smooth curved surface that is continuous from the curved shoulder subordinate unit.

In the case of manufacturing a bottle type can having a shoulder having a tapered surface (a frusto-conical inclined surface) and a lower curved surface, a curved surface of the lower portion of the shoulder is formed in the next forming step. A pusher for wrinkle suppression having a taper surface of a predetermined angle following the outer surface of the distal end portion, and a drawing die having a taper surface facing the same slope as the taper surface of the pusher and a convex curved surface extending outside thereof on the inner surface of the distal end portion; Using a drawing punch with a smaller diameter than the drawing punch used in the previous process, the bottom corner of the bottomed cylindrical portion drawn and formed from the bottom of the can in the previous process with a pusher and each tapered surface of the die While pinching and wrinkling, the bottom of the bottomed cylindrical portion is redrawn by a punch into a smaller-diameter bottomed cylindrical shape, and such redrawing is performed so that the bottomed cylindrical portion has a predetermined diameter of the mouth and neck. Repeat as necessary until it is almost the same as Since I, the inclined surface of the shoulder formed following the curved surface of the shoulder subordinate unit by redrawing, reshaping extended press into a smooth tapered surface continuous from the curved shoulder subordinate unit.

According to the method for manufacturing a bottle-type can as described above, a bottomed cylindrical can formed integrally from a thin metal plate is provided with a small-diameter bottomed cylindrical portion and a lower portion of a shoulder portion. In order to form a curved surface, since both are molded in a single molding process using a curved surface molding pusher and drawing die of a specific shape, a small diameter bottomed cylindrical part is molded from the can bottom Compared to the case where the curved surface of the lower part of the shoulder is preformed in another process before the process, the number of processes can be reduced by one and productivity can be improved, and a cylindrical can with a bottom is formed. In the drawing and ironing process, the outer peripheral surface of the tip of the punch is formed into a curved surface with a large radius of curvature, so that the curved surface of the lower shoulder is simultaneously formed in the drawing and ironing process. It is possible to reduce the danger that wrinkles will occur on the surface.

When the remaining portion of the shoulder and the mouth and neck are formed by re-drawing, a newly formed bottomed bottom is formed by using a pusher and a drawing die for suppressing wrinkles having specific shapes, respectively. It is possible to redraw the material from the side of the shoulder portion already formed on the cylindrical portion without greatly drawing in the material, and it is possible to form the shoulder portion without generating wrinkles due to the drawing in of the material. The shoulder can be formed without forming a large step, and when the shoulder formed by re-drawing is pushed out and re-formed, a wrinkle or a forming mark (a forming mark due to a step-shaped step) is formed. ) Can be formed on a smooth and beautiful inclined surface (a dome-shaped curved surface or a smooth tapered surface) without leaving ()).

[0023]

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

FIGS. 1 to 8 relate to a first embodiment of the method for producing a bottle can of the present invention.
Shows the shape of the bottle-shaped can to be manufactured, and FIGS.
FIG. 6 shows a molding state in a first step of top dome molding, FIG. 7 shows a molding state in a second step of top dome molding, and FIG. It shows a molding state in a fourth step (reform step) of top dome molding.

FIGS. 9 to 11 relate to a second embodiment of the method for producing a bottle can of the present invention.
Are examples of different shapes of bottle-shaped cans (A),
(B) is shown, FIG. 10 shows a molding state in a second step of top dome molding, and FIG. 11 shows a molding state in a fourth step (reforming step) of top dome molding.

First, a first embodiment of a method for manufacturing a bottle can according to the present invention will be described below. The bottle can manufactured by the method of the present embodiment (first embodiment) is as shown in FIG. Above the large-diameter trunk portion 2, via a shoulder 3 inclined by a dome-shaped curved surface having a vertical cross section,
A small-diameter cylindrical mouth-neck portion 4 is integrally formed, and a lower end opening of the body portion 2 is closed by tightly fastening a bottom cover 5. Curl part 4a
And a screw portion 4b for screwing with a screw portion of the pill fur proof cap, a bead portion 4c for locking a break band of the pill fur proof cap, and a small diameter portion 4d thereunder.

Each step of manufacturing such a bottle-shaped can 1 will be schematically described. First, as shown in FIG. 2, a thin metal plate as a raw material is punched into a disc shape to form a blank for each can. By drawing the blank (a thin metal plate) into a cup shape, drawing and ironing the side wall of the cup, and then trimming the opening end side to a predetermined length, A bottomed cylindrical DI can with one open end is manufactured.

In order to form a top dome on the bottom side of the DI can manufactured as described above, as shown in FIG.
In FIG. 5, the bottom side of the can is shown as the top). First, in the first step of forming the top dome, the can bottom corner (bottom and bottom) is formed with respect to the bottomed cylindrical can produced in the previous step. The nearby body is formed into a curved surface with a vertical cross-section of an arc (the curved surface below the shoulder of the bottle-shaped can), and the flat bottom is drawn into a cylindrical shape with a smaller diameter than the body. Then, in the second step, the newly drawn bottomed cylindrical portion is redrawn into a smaller diameter bottomed cylinder, and in the third step, such redrawing is repeated once again. Then, after reducing the diameter of the bottomed cylindrical portion to approximately the same as the diameter of the mouth and neck portion, in the fourth step, by repeating such redrawing, the original curved surface (lower shoulder portion of the bottle-shaped can) Reshaping the shoulder portion formed following the curved surface of the curved surface) into a continuous smooth curved surface .

Next, as shown in FIG. 4, in a fifth step and a sixth step of forming the top dome, the bottomed cylindrical portion formed to have substantially the same diameter as the mouth and neck portion is subjected to two times of port drawing. After trimming the upper end closed portion (bottom portion) to form a mouth and neck with an open upper end, as shown in FIG. 5, in each step for screw and curl forming on the mouth and neck, The open end of the mouth and neck is formed into an annular curl by wrapping around the outside, and the cylindrical peripheral wall of the mouth and neck that extends downward from the curl is formed into a screw or a bead (small diameter portion below). Further, after neck and flange processing is performed on the lower end opening edge of the body opposite to the mouth and neck, a bottom cover made of a thin metal sheet is double-wrapped around the lower end opening edge. The bottle-shaped can 1 as shown in FIG. 1 is completed by integrally fixing by the fastening method.

A supplementary explanation of a specific example of the production of the above-mentioned bottle-shaped cans is as follows. The thin metal plate as a raw material is made of a thermoplastic resin such as a polyester resin or a polypropylene resin on both sides of an aluminum alloy plate. A metal sheet having a thickness of 0.1 to 0.4 mm obtained by laminating a film, and in this embodiment, a thickness of 0.315 mm
A polyethylene terephthalate film was applied to the 3004H191 aluminum alloy plate of
And a thin metal plate laminated so as to have a thickness of 20 μm on the outer surface side.

The method of laminating the thermoplastic resin film on the thin metal plate is not limited to the case where the thermoplastic resin film is directly heat-bonded to the metal surface of the thin metal plate.
In some cases, a thermoplastic resin film is thermally bonded to a metal surface of a thin metal plate via an adhesive primer layer, a curable adhesive layer, or a thermoplastic resin layer having good thermal adhesion.

The blank for each can was prepared by punching the above-mentioned thin metal plate into a disk having a diameter of 170 mm. This disk-shaped blank was 48.3 mm in height and 1 mm in outer diameter.
After being drawn into a 00 mm cup shape, the side wall of the cup is drawn and ironed, and then the end on the opening end side is trimmed to have a height of 171.5 mm and an outer diameter of 65.9 mm. The bottom is a cylindrical DI can.

For such a bottomed cylindrical DI can,
Prior to drawing the bottom of the can as a top dome (forming the bottom of the can into the shoulder and mouth and neck), the DI can is heated to the melting point of the polyethylene terephthalate resin covering the can and then rapidly cooled. By making the polyethylene terephthalate film amorphous, the adhesion between the film and the aluminum alloy plate is improved.

As for the bottom lid for closing the lower end opening of the body opposite to the mouth and neck, an aluminum alloy (5182-H39) having a 0.02 mm-thick polyethylene terephthalate film heat-sealed on both sides Made with a thickness of 0.2
It is a bottom lid having a diameter of 85 mm and a diameter of 62.6 mm, and is integrally fixed to a lower end opening edge of a neck portion subjected to neck and flange processing by double winding.

In this regard, the process for drawing the bottom of the DI can into a shoulder portion and a mouth and neck portion (the process shown in FIG. 3) of the bottle type can manufacturing process as described above is the same as the present embodiment. In the first embodiment, the neck and neck are drawn by the following method.

First, as shown in FIG. 6, the DI can formed into a cylindrical shape with a bottom by drawing and ironing has the same convex curved surface as the curved surface at the lower part of the shoulder of the bottle-shaped can at the outer surface at the tip end. Pusher 12 for forming a curved surface, drawing die 11 having a concave curved surface corresponding to the curved surface at the lower part of the shoulder on the inner surface at the tip, and drawing punch 1 having a diameter smaller than the inner diameter of the body of the can
By pressing the can bottom corner portion with the pusher 12 and the die 11 using 3, the can bottom corner portion is formed into an arc-shaped curved surface (curved surface that is a curved surface at the lower part of the shoulder) 31 in a vertical section, The flat can bottom 41 having a smaller diameter than the body portion is drawn by the punch 13 into a cylindrical shape with a smaller diameter, so that the small-diameter bottomed cylindrical portion 42 and the curved surface 31 below the curved portion (curved surface at the lower part of the shoulder) 31 are formed. It is molded in one molding step.

Thereafter, as shown in FIG. 7, for the newly drawn bottomed cylindrical portion 42, a cross-section straight line approximating the cross-sectional arc of the imaginary curved surface following the curved surface 31 below the shoulder formed in the previous step. A pusher 15 for suppressing wrinkles having a tapered surface, a die 14 having a tapered surface having the same inclination as the tapered surface of the pusher 15 and having a large outer diameter, and a smaller diameter than the punch 13 for drawing used in the previous step. In the state where the bottom corner portion of the bottomed cylindrical portion 42 is wrinkled down by the respective tapered surfaces of the pusher 15 and the die 14 using the drawing punch 16 of the above, the punch 16 is used to redraw into a smaller diameter bottomed cylindrical shape. After that, by repeating the redrawing of the bottomed cylindrical portion 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 4.

After forming the curved surface 31 at the lower portion of the shoulder and the cylindrical portion 42 with the bottom on the bottom side of the can, re-drawing is performed a plurality of times (two times) as shown in FIG. In addition, the bottomed cylindrical portion is reduced in diameter to substantially the same diameter as the mouth and neck portion 4 having a predetermined diameter, and a shoulder portion comprising a lower curved surface 31 and a plurality of (two) tapered surfaces 32 and 33 similar thereto. Is formed, and a plurality of forming tools (a die 17 and a pusher 18) having a shape of an imaginary curved surface extending from the lower curved surface 31 are formed by forming the plurality of tapered surfaces 32, 33 of such shoulders.
As a result, the entire shoulder portion is reformed (reformed) into a smooth dome shape along the previously formed lower curved surface 31.

According to such a method of the present embodiment (first embodiment), a small-diameter bottomed cylindrical portion 42 is provided on the bottom side of a bottomed cylindrical can formed integrally from a thin metal plate. And the curved surface 31 at the lower part of the shoulder, both of which are molded in one molding process using the curved surface molding pusher 12 and the drawing die 11 having a specific shape. Compared to the case where the curved surface 31 at the lower part of the shoulder is preliminarily formed before being formed into the bottomed cylindrical portion 42, the number of steps can be reduced by one and the productivity can be improved. When molding a cylindrical can with a bottom, the outer peripheral surface of the tip portion of the punch is formed into a curved surface with a large radius of curvature, thereby simultaneously forming the curved surface 31 at the lower part of the shoulder,
It is possible to reduce the possibility that wrinkles are generated on the curved surface 31 at the lower part of the shoulder.

Then, when redrawing the can having the curved surface 31 at the lower part of the shoulder, as shown in FIG. 7, by using the pusher 15 for pressing the wrinkle and the drawing die 14 having a specific shape. A bent portion at the lower end of the bottomed cylindrical portion 42 (a boundary portion between the shoulder portion already formed and the bottomed cylindrical portion) L
Without forming a large step,
The shoulder formed following the curved surface 31 at the lower part of the shoulder is formed as a plurality of tapered surfaces 32 and 33 which approximate a curved surface instead of a step shape without generating wrinkles due to drawing in of the material at the time of redrawing. As a result, when the plurality of tapered surfaces 32, 33 formed by re-drawing are stretched to a smooth curved surface and re-formed, the shoulder portion 3 does not leave wrinkles or forming marks. Can be formed into a smooth and beautiful dome-shaped curved surface.

As for the die 14 and the pusher 15 used in such redrawing, the outer diameter of the tapered surface of the die 14 is larger than the outer diameter of the pusher 15 (extending outward). This is very important. That is, in order not to leave the bent portion L at the lower end of the bottomed cylindrical portion formed in the previous step (the boundary line portion between the already formed shoulder portion and the bottomed cylindrical portion) L as a step on the shoulder portion. It is necessary to continuously perform re-drawing until the bent portion L is drawn between the die 14 and the pusher 15, but the bent portion L can be connected to the die 14 and the pusher without any resistance during the re-drawing. As a result, as described in detail later, it is the same as drawing with a large drawing ratio, and wrinkles are formed on the curved surface 31 at the lower part of the shoulder already formed. Will be generated.

On the other hand, by making the outer diameter of the tapered surface of the die 14 larger than the outer diameter of the pusher 15, the bent portion L at the lower end of the bottomed cylindrical portion formed in the previous step can be formed. Even if the re-drawing is continued until it is drawn between the pusher 15 and the pusher 15, the bent portion L hits the tapered surface of the die 14 protruding outward from the pusher 15, so that the tapered surface of the die 14 The bent portion L is gradually pulled between the die 14 and the pusher 15 due to the resistance due to the frictional contact.

The shoulder forming by drawing (redrawing) using the drawing die 14 and the wrinkle-pressing pusher 15 as described above will be described in more detail. A wrinkle-pressing tool (die and pusher) used for drawing is used. The original role of) is to press the material with a certain pressure to prevent wrinkles from being generated by the circumferential shrinkage when the original metal plate material flows into the drawing die by the punch. It is to convert to a predetermined thickness, but when the material is pressed by such a wrinkle holding tool, if the stop by the punch is stopped in the middle and taken out, the shape of the wrinkle holding tool can be transferred to the material as it is it can.

Therefore, as described above, the bottomed cylindrical portion is drawn from the flat can bottom of the DI can, and the drawing process is repeated to gradually reduce the diameter of the bottomed cylindrical portion. At the time of forming (redraw forming), by stopping the drawing by the punch in the middle, the portion drawn by the punch is formed as a small-diameter bottomed cylindrical portion (finally a cylindrical mouth and neck portion), The portion pressed by the wrinkle holding tool is formed as a shoulder portion following the curved surface of the already formed lower portion of the shoulder portion.

When a wrinkle-reducing tool (die and pusher) conforming to the shape of the bottom corner of the bottomed cylindrical portion is used as a wrinkle-reducing tool when the cylindrical portion having the bottom is drawn, a plurality of tools are required. When performing the drawing process twice, the shoulder portion from the curved surface of the lower shoulder portion formed earlier to the mouth and neck, that is, the shoulder portion formed by multiple drawing processes,
It will be formed in a step shape, and even if it is stretched out and re-formed, traces of the step shape will remain in a ring shape on the shoulder.

On the other hand, when a wrinkle-repressing tool (die and pusher) that matches the curved shape of the shoulder following the curved surface of the lower part of the shoulder that has already been formed is used, when it is squeezed by a punch, the original shape is obtained. As the material moves from the bottom cylinder to the squeezed bottom cylinder, the material of the curved surface at the lower part of the shoulder that has already been formed is drawn into the newly formed bottom cylinder, and as a result, Means that the drawing process is performed at a drawing ratio larger than a predetermined drawing ratio, and wrinkles are generated on the curved surface at the lower part of the shoulder.

On the other hand, in the method of the present embodiment (first embodiment), as a wrinkle pressing tool at the time of redraw forming, a cross-sectional straight line approximating a cross-sectional arc of a virtual curved surface following the curved surface 31 at the lower part of the shoulder is used. The use of the wrinkle-repressing pusher 15 having a tapered surface and the drawing die 14 having a tapered surface having the same inclination as the tapered surface of the pusher 15 and having a large outer diameter allow transfer of a wrinkle-retaining tool. The stepped shape is not formed on the shoulder, and the shoulder can be formed as a plurality of tapered surfaces approximating a curved surface, and the bent portion L at the lower end of the bottomed cylindrical portion formed in the previous step is formed. Even if re-drawing is continued until the bent portion L is drawn between the die 14 and the pusher 15 so as not to leave a step portion, the material is drawn from the already formed shoulder portion and wrinkles are generated. To let Never.

The number of repetitions of the redrawing of the bottomed cylindrical portion as described above will be further described. One drawing amount (drawing ratio) is determined by the thickness and the material of the DI can. In the case of redrawing with a thin metal plate (aluminum alloy or steel) of 0.1 to 0.4 mm like a DI can for beverages, the drawing ratio is usually 1.5.
It is considered to be within, if it is more than that, even if wrinkles are generated or wrinkle holding pressure is increased, it will cause material breakage, and by further redrawing, work hardening will cause the critical draw ratio to be further reduced Therefore, for example, in the case of a beverage can of beer or carbonated beverage, the can body diameter is generally 66 mm (211 mm).
Diameter) can be used, so the final diameter of the mouth and neck is 3
Assuming that the drawing ratio is 1.3 mm when the drawing ratio is 0 mm, three drawing steps (two redrawing steps) are required. However, in the case of manufacturing a bottle-type can having a particularly large mouth-neck diameter with respect to the can body diameter (for example, a bottle-type can having an outside diameter of the mouth-neck portion equal to or more than の of the can body outer diameter). In this case, it is also possible to perform only two drawing steps (one re-drawing step).

Although the first embodiment of the method of the present invention has been described above, the present invention for producing a bottle can having a shoulder shape different from that of the bottle can according to the first embodiment is further described. A second embodiment of the method will be described below.

The bottle-type can manufactured by the method of the second embodiment of the present invention is different from the bottle-type can manufactured by the method of the above-described first embodiment except that the shape of the shoulder 3 is different. Basically, it is the same (specifically, it is not necessarily the same up to the length of the torso and the mouth and neck), and FIG.
As shown in (B), the shape of the shoulder 3 is the lower curved surface 3a.
A tapered surface (truncated cone-shaped inclined surface) 3b continuously and smoothly continues above. Although the specific example shown in FIG. 9A and the specific example shown in FIG. 9B differ in the length and angle of the tapered surface 3b, and the curvature of the lower curved surface 3a is different. Are basically manufactured by the same manufacturing method.

The outline of the manufacturing process of such a bottle-shaped can 1 is not particularly different from that shown in FIGS. 2 to 5 in the description of the first embodiment, and as shown in FIG. A pusher 12 for forming a curved surface, which has the same convex curved surface on the outer surface of the lower end of the shoulder of the bottle-shaped can to be molded, and a constriction on the inner surface of the distal end, which has a concave curved surface corresponding to the lower surface of the shoulder. Using a die 11 and a drawing punch 13 having a diameter smaller than that of the body of the can, the bottom of the DI can formed into a cylindrical shape with a bottom by drawing and ironing is used as a shoulder in a single forming step. The method of forming the lower curved surface 31 and the small-diameter bottomed cylindrical portion 42 is not different from the method of the first embodiment.

However, in the method of the first embodiment,
While the entire shoulder including the curved surface at the lower part of the shoulder is formed as a dome-shaped curved surface, the method according to the second embodiment has a smooth tapered surface (frustoconical shape) at the part following the curved surface at the lower shoulder. In the method of the first embodiment, in the redraw forming after forming the curved surface 31 at the lower part of the shoulder and the small-diameter bottomed cylindrical portion 42, as shown in FIG. Then, while the shoulder is reshaped as shown in FIG. 8, in the method of the second embodiment, redrawing is performed as shown in FIG. 10 and the shoulder is formed as shown in FIG. Has been reshaped.

That is, in the method of the first embodiment, the curved surface 3 at the lower part of the shoulder is used as a wrinkle pressing tool for redraw forming.
Wrinkle-pressing pusher 1 having a tapered surface having a linear cross-sectional shape approximating a circular arc of a virtual curved surface following 1 on the outer surface of the tip portion
5 and a drawing die 14 having a tapered surface having the same inclination as the tapered surface of the pusher 15 and a large outer diameter on the inner surface at the tip end.
When the drawing process is repeated using the above, the inclination angle of the tapered surfaces of the die 14 and the pusher 15 slightly changes from that in the previous drawing process.
In the method of the embodiment), as shown in FIG. 10, a pusher 22 for suppressing wrinkles having a tapered surface of a predetermined angle following the curved surface of the lower part of the shoulder on the outer surface of the distal end portion is opposed to the taper surface of the pusher 22 at the same inclination. The use of a drawing die 21 having a tapered surface 21a to be formed and a convex curved surface 21b extending outside thereof on the inner surface of the tip portion allows the die 21 to be used even when drawing is repeated.
And the inclination angle of the tapered surface of the pusher 22 is always a predetermined constant angle.

Regarding the reshaping (reforming) of the shoulder formed by redrawing, the method of the first embodiment employs a pair of forming tools (a die 17 and a die 17) having a virtual curved surface shape extending from the lower curved surface 31. While the entire shoulder is reshaped into a smooth dome shape along the previously formed lower curved surface 31 by being extended by the pusher 18), the present embodiment (second embodiment) In the method (1), as shown in FIG. 11, a pressing force is applied to the bottom of the mouth and neck 4 (the bottomed cylindrical portion whose diameter is reduced substantially to the mouth and neck) by the punch 25, so that the shoulder has a bottom side. In a state where a tensile force is applied to the lower portion, the pair of forming tools (die 23 and pusher 24) having a tapered surface having a predetermined angle extending from the lower curved surface 31 are pressed and extended to thereby form the lower portion formed earlier. Curved surface 31 It is reshaped into a tapered surface that is continuous upward

The die 21 used for redrawing is
Regarding the pusher 22 and the pusher 22, it is important that a convex curved surface 21b is provided outside the tapered surface 21a of the drawing die 21 (a tapered surface having the same inclination and substantially the same diameter as the tapered surface of the pusher 22). That is, as described in the description of the first embodiment, when redrawing is continuously performed until the bent portion L at the lower end of the bottomed cylindrical portion formed in the previous step is drawn between the die and the pusher, The bent part L without any resistance
Is drawn between the die and the pusher, the result is the same as drawing with a large drawing ratio, and wrinkles are generated on the shoulder.

On the other hand, in the present embodiment (second embodiment), since the convex curved surface 21b is provided outside the tapered surface 21a of the die 21, the bottomed cylindrical portion formed in the previous step is formed. Even if the redrawing is continuously performed until the bent portion L at the lower end is drawn between the die 21 and the pusher 22, the bent portion L hits the convex curved surface 21 b of the die 21 projecting outward from the pusher 22, After that, the already formed inclined portion of the shoulder portion comes into frictional contact with the convex curved surface 21b of the die 21 and receives resistance, so that the die 21 and the pusher 2 are little by little.
2 and as a result, the die 21
In the state where the convex curved surface 21b is slightly transferred to the shoulder portion, the shoulder portion can be formed without leaving a stepped portion due to the bent portion and without generating wrinkles.

As a result, as shown in FIG. 11, when the curved surface 31 at the lower part of the shoulder and the cylindrical portion 41 with the bottom are formed on the bottom side of the can and re-drawing is performed a plurality of times (two times) as shown in FIG. To
The shoulder has a slightly concave surface (the convex curved surface 21b of the die 21) at the lower end.
Are formed as a plurality (two surfaces) of tapered surfaces 34, 35 having a portion to which a slight transfer is made. By applying a pressing force to the bottom of the bottomed cylindrical portion whose diameter has been reduced to the neck, a pair of tapered surfaces having a predetermined inclination angle are applied in a state where a pulling force is applied to the shoulder to the bottom side. By pressing and extending by pressing with a forming tool (die 23 and pusher 24), an inclined surface (curved surface 31 becomes curved surface 3a, and tapered surfaces 34, 35 become tapered surface 3b) Can be reshaped (reformed).

According to such a method of the present embodiment (second embodiment), when redrawing a can formed with the curved surface 31 at the lower part of the shoulder and the cylindrical portion 41 with the bottom, as shown in FIG. As described above, by using the pusher 22 for suppressing wrinkles and the drawing die 21 having a specific shape, a large step is formed by leaving the bent portion L caused by the lower end of the bottomed cylindrical portion 42 to be shallow. The curved surface 31 at the lower part of the shoulder portion does not generate wrinkles due to the drawing in of the material at the time of redrawing.
Can be formed as a plurality of tapered surfaces 34 and 35 having a slightly concave curved surface at the lower end, so that the shoulder formed by redrawing can be formed into a die 2.
3 and without being wrinkled or forming marks when pressed and re-formed by the pusher 24, FIG.
As shown in (A) and (B), the shoulder 3 can be formed on a beautiful inclined surface where a smooth tapered surface 3b continues upward from the curved surface 3a at the lower part of the shoulder.

In each of the above-described embodiments (the first and second embodiments), in each case, the thermoplastic resin such as a polyester resin or a polypropylene resin is formed on both sides of the aluminum alloy plate. We manufacture bottle-type cans from thin metal sheets with a synthetic resin film laminated with a resin film.However, we manufacture bottle-type cans from such thin metal sheets with a synthetic resin film, making it difficult to post-paint. Corrosion resistance can be sufficiently imparted to the small-diameter threaded mouth and neck.

In particular, since a thermoplastic resin film is used as a synthetic resin film for covering the metal surface of a metal sheet, drawing, bending and stretching (stretching), ironing, beading, and screwing of the metal sheet are performed. The thermoplastic resin film layer acts as a lubricant during processing such as part forming processing, and the thermoplastic resin film layer can be stretched or bent following the elongation and bending processing of the metal sheet, so that the thickness has been reduced. Despite having a torso, and having a small diameter mouth and neck with curl molding and screw molding,
The coating state of the coating can be maintained well until after the can is formed. (It is desirable from the viewpoint of recycling that the bottom lid for closing the lower end opening of this bottle-shaped can be formed of an aluminum alloy plate laminated with the same thermoplastic resin film as that used for the can body).

In each of the above-described methods for manufacturing a bottle-shaped can according to the present embodiment, in each case, the vicinity of the bottom of the thinned body (sidewall portion) is added to the shoulder portion of the cylindrical can with a bottom. (Part of the shoulder) is re-formed. In order to prevent wrinkles from occurring during this re-forming, the thickness of the re-formed part of the body (the side wall near the bottom) is required. It is preferable to set the thickness to 60% or more of the thickness of the bottom portion (substantially the same as the thickness of the metal sheet before processing).

Although the embodiments of the method for producing a bottle-shaped can of the present invention have been described above, the present invention is not limited to the above-described embodiments. Not only the aluminum alloy plate as shown in the embodiment, but also ultra-thin tin-plated steel plate, nickel-plated steel plate, surface-treated such as various metal plating and chemical conversion treatments used for can making, electrolytic chromic acid treatment It is also possible to use surface-treated steel sheets such as steel sheets, galvanized steel sheets, etc., and to use a thin metal sheet that is not coated with a synthetic resin film such as a thermoplastic resin film, and then apply post-painting after forming the can. It is also possible to cover the metal surface with a synthetic resin film.

When integrally forming a cylindrical can with a bottom from a thin metal plate having a thickness of 0.1 to 0.4 mm so that the body portion is thinner than the bottom portion, the thin metal plate is punched out to form a cup. After drawing, it may be obtained by performing at least one step of thinning the body wall by performing stretching while redrawing (redrawing step), or redrawing a cup formed by drawing. It may be obtained by performing one or more steps of thinning the body wall by performing bending and stretching and ironing while processing, and further performing bending and stretching at the time of redrawing, and then performing ironing. It may be obtained by doing.

Further, regarding the specific structure of the bottle-shaped can to be manufactured, in the above embodiment, the bottle-shaped can is formed with a screw portion for screwing a cap on the mouth-neck portion. As for the shape, only the curl part is provided, and the mouth and neck are sealed using an aluminum alloy sheet easy-to-open cap (the skirt part of the cap is crimped along the outer surface of the curl part). Also, as for the overall shape of the bottle-shaped can, after forming a curled portion on the mouth and neck, the opening end on the body side is separated from the opening end of another bottomed cylinder with an adhesive or the like. Needless to say, the design can be changed as appropriate, for example, it can be joined to produce a tall bottle can.

[0065]

According to the method of manufacturing a bottle-shaped can of the present invention as described above, a bottomed cylindrical can having a body portion formed thinner than a bottom portion is formed by drawing the bottom of the can. When integrally forming the slanted shoulder and the small-diameter cylindrical mouth and neck, the curved surface at the lower part of the shoulder is simultaneously formed with the drawing of the mouth and neck, which may cause wrinkles on the curved surface at the lower part of the shoulder. The number of steps can be reduced, the number of steps can be reduced, the productivity can be improved, and even if the drawing process is repeated several times in order to reduce the diameter of the mouth and neck to a predetermined diameter, it can be applied to the shoulder. Without forming large steps or wrinkles,
As a result, the shoulder portion can be formed on a smooth and beautiful inclined surface without leaving wrinkles or molding marks when the shoulder portion is reformed.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view showing an example of a bottle-shaped can to be manufactured in a first embodiment of a method for manufacturing a bottle-type can of the present invention.

FIG. 2 is an explanatory side view showing a part (from a blank to a cylindrical can with a bottom) of a manufacturing process of a bottle can.

FIG. 3 is an explanatory side view showing a part of the manufacturing process of the bottle-shaped can (forming the top dome of the bottom of a cylindrical can having a bottom).

FIG. 4 is an explanatory side view showing a part of the manufacturing process of the bottle-shaped can (opening forming and trimming of a bottomed cylindrical mouth and neck formed by top dome forming).

Fig. 5: Part of the manufacturing process of a bottle-shaped can
Curl molding and neck and flange processing of the opening at the bottom of the can body)
FIG.

FIG. 6 is a view showing a first embodiment of the present invention. In the top dome forming in the manufacturing process of the bottle-shaped can, in the first step, a curved surface at the lower portion of the shoulder and a small-diameter bottomed cylindrical portion are provided on the bottom side of the DI can. Sectional explanatory drawing which shows the state at the time of drawing.

FIG. 7 is a view of the first embodiment of the present invention, in which the curved surface at the lower part of the shoulder and the small-diameter bottomed cylindrical portion are formed by drawing in the first step in the top dome forming process of the bottle can manufacturing process. Sectional explanatory drawing which shows the state at the time of reducing the diameter of a cylindrical part with a bottom by drawing (redrawing) in the 2nd process of a DI can.

FIG. 8 is a view showing a first embodiment of the present invention. In the top dome forming process of the bottle type can manufacturing process, the DI can having the shoulder portion and the mouth and neck portion formed in the second and third steps, Sectional explanatory drawing which shows the state at the time of reshaping (reforming) the whole shoulder part into a smooth dome shape in four processes.

FIG. 9 shows examples (A) and (B) of bottle-type cans to be manufactured according to the second embodiment of the method for manufacturing a bottle-type can of the present invention.
FIG.

[FIG. 10] In the second embodiment of the present invention, in the top dome forming in the manufacturing process of the bottle-shaped can, in the first step, the curved surface at the lower portion of the shoulder and the small-diameter bottomed cylindrical portion were formed by drawing on the bottom side of the can. Sectional explanatory drawing which shows the state at the time of reducing the diameter of a cylindrical part with a bottom by drawing (redrawing) in the 2nd process of a DI can.

FIG. 11 is a view showing a second embodiment of the present invention. In the top dome molding in the manufacturing process of the bottle-shaped can, the DI can having the shoulder and the mouth and neck formed in the second and third steps is replaced with the first can. Sectional explanatory drawing which shows the state at the time of reshaping (reforming) the whole shoulder part into a smooth dome shape in four processes.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Bottle can 2 Body 3 Shoulder 4 Neck and neck 11 Drawing die (for forming a curved surface below the shoulder) 12 Pusher for forming a curved surface (for forming a curved surface below the shoulder) 13 Drawing Punch 14 Die for drawing (for pressing wrinkle) (die for redrawing) 15 Pusher for pressing wrinkle 16 Punch for drawing (redrawing punch) 21 Die for drawing (for pressing wrinkle) (die for drawing again) 22 Pusher for wrinkle control 31 Curved surface at the lower part of shoulder 32 Tapered surface (formed as part of shoulder by redrawing) 33 Tapered surface (formed as part of shoulder by redrawing) 34 Tapered surface 35 (formed as part of shoulder by redrawing) Tapered surface 35 (formed as part of shoulder by redrawing)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) B65D 8/04 B65D 1/00 C

Claims (5)

[Claims] 1. A bottomed cylindrical can which is integrally formed from a thin metal plate having a thickness of 0.1 to 0.4 mm so that a body portion is thinner than a bottom portion, is further processed on the bottom side of the can. In the method of manufacturing a bottle-type can in which the inclined shoulder portion and the small-diameter cylindrical mouth-and-neck portion are integrally formed by applying, the bottle to be molded with respect to the can that is integrally molded into a bottomed cylindrical shape A curved surface forming pusher having the same convex curved surface as the curved surface of the lower shoulder portion on the outer surface of the tip, a drawing die having a concave curved surface corresponding to the curved surface of the lower shoulder portion on the inner surface of the distal end, and the can Pressing the can bottom corner with a pusher and die using a drawing punch with a diameter smaller than the body of the can, and drawing the bottom of the can with a punch into a bottomed cylindrical shape with a diameter smaller than the body. A small-diameter bottomed cylindrical part and a curved surface below the shoulder part below the can bottom side After forming in one molding process,
In the next forming step, a pusher for suppressing wrinkles having a tapered surface with a vertical cross-section linear shape similar to the vertical cross-section arc of the virtual curved surface following the curved surface on the outer surface of the tip, and an outer diameter with the same inclination as the taper surface of the pusher Using a drawing die with a large tapered surface on the inner surface of the tip and a drawing punch with a smaller diameter than the drawing punch used in the previous process, a bottomed cylinder drawn from the bottom of the can in the previous process While pressing the bottom corner of the part between the taper surfaces of the pusher and the die and pressing it down, the bottom of the bottomed cylindrical part is redrawn by a punch to a smaller diameter bottomed cylinder, and such redrawing is performed. Repeat as necessary until the diameter of the bottomed cylindrical portion becomes substantially the same as the diameter of the predetermined mouth and neck, and then the shoulder inclined surface formed by approximation to a curved surface by redrawing is replaced with a shoulder portion. From lower surface to continuous smooth surface Method for manufacturing a bottle-shaped can which is characterized in that so as to reshaped extended to. 2. A bottomed cylindrical can which is integrally formed from a metal sheet having a thickness of 0.1 to 0.4 mm so that a body portion is thinner than a bottom portion, is further processed on the bottom side of the can. In the method of manufacturing a bottle-type can in which the inclined shoulder portion and the small-diameter cylindrical mouth-and-neck portion are integrally formed by applying, the bottle to be molded with respect to the can that is integrally molded into a bottomed cylindrical shape A curved surface forming pusher having the same convex curved surface as the curved surface of the lower shoulder portion on the outer surface of the tip, a drawing die having a concave curved surface corresponding to the curved surface of the lower shoulder portion on the inner surface of the distal end, and the can Using a punch for drawing with a diameter smaller than the body of the can, while pressing the corner of the can bottom with a pusher and a die, draw the bottom of the can with a punch to form a cylinder with a bottom with a diameter smaller than the body. A small-diameter bottomed cylindrical part and a curved surface below the shoulder part below the can bottom side After forming in one molding process,
In the next forming step, a pusher for suppressing wrinkles having a tapered surface of a predetermined angle following the curved surface on the outer surface of the distal end portion, a tapered surface facing the same inclination as the tapered surface of the pusher and a convex curved surface following the outside thereof. Using the drawing die on the inner surface of the tip and the drawing punch smaller in diameter than the drawing punch used in the previous process, the bottom corner of the bottomed cylindrical portion drawn from the bottom of the can in the previous process While pressing the wedge between the taper surfaces of the pusher and the die, the bottom of the bottomed cylindrical part is redrawn by a punch to form a smaller diameter bottomed cylinder by punching, and such redrawing is performed on the bottomed cylindrical part. Repeatedly as necessary until the diameter becomes substantially the same as the diameter of the predetermined neck and neck, then the shoulder slope formed following the curved surface of the lower shoulder by re-drawing, the lower shoulder Press from curved surface to continuous smooth taper surface Method for manufacturing a bottle-shaped can which is characterized in that so as to reshaped extended. 3. A thin metal plate as a material for integrally forming a cylindrical can with a bottom is an aluminum alloy plate coated with a thermoplastic resin film.
Or the manufacturing method of the bottle-shaped can of 2. 4. A thin metal sheet, which is a material for integrally forming a cylindrical can with a bottom, is obtained by coating a surface-treated steel sheet with a thermoplastic resin film.
3. The method for producing a bottle-shaped can according to claim 1. 5. A cylindrical can with a bottom, which is integrally formed from a thin metal plate, so that the thickness of a side wall portion near the bottom of the can is less than the thickness of the original thin metal plate and is 60% or more of the thickness. The method for producing a bottle-shaped can according to any one of claims 1 to 4, wherein the method is performed.