Metal container for reform and manufacturing method for lid fitting type metal container

Abstract

To provide a metal container for reform whose opening diameter can be easily changed so as to be adapted to the lids of various sizes.SOLUTION: A metal container for reform 10 used in a manufacture of a lid fitting type metal container has a cylindrical body 1 with a closed lower end, and a curled part 9 for reform of a shape expanding outward is formed at the upper end of the body 1, and in a side cross-sectional view, a radial direction width W and an axial direction length H of the curled part for reform 9 are set to satisfy W>H or W<H.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a lid-fitted metal container that is used by fitting and fixing a lid, and more specifically, to a metal container for reform used in the manufacture of a lid-fitted metal container, and a method for manufacturing a lid-fitted metal container using the metal container for reform. [Background technology]

[0002] Generally, metal containers obtained by metal forming processes (punching, drawing, and ironing) are widely used for filling with liquids such as beverages, attaching lids to the containers, and selling them.

[0003] When attaching a lid to a metal container such as the one described above, the lid is generally fitted to the opening of the metal container. When fitting a lid using a screw engagement, threads must be formed on the outer surface of the opening of the container and on the inner surface of the skirt of the lid. However, when fitting using a screw engagement, such a cumbersome method as forming threads is not necessary, and the diameter of the lid can be set to a size that allows it to fit according to the size of the opening of the metal container.

[0004] For example, Patent Document 1 proposes a sealing method in which a lid having an engaging space outside the outer periphery of a container (metal container) having an outer curled portion at its open end is attached to the mouth of the container, and the curled portion is deformed to fill the engaging space. That is, in this method, with the lid placed over the mouth of the container, the outer curled portion formed on the mouth of the container is deformed (squashed) so as to be pressed into the engaging space formed in the lid, thereby forming a seal with the lid.

[0005] However, in recent years, in the field of beverage containers, retail stores and restaurants have been selling coffee, beer, and other beverages over the counter, filling these beverages into cup-shaped containers, attaching lids, and serving them to consumers. In this type of sales format, the designs and sizes of lids attached to containers vary depending on the type of beverage, the sales manufacturer, and so on, and a variety of lids are produced. In particular, the lids used in this type of sales format are mostly made of plastic rather than metal, and they also come in a variety of sizes. Therefore, if a metal container is to be used in this type of sales format, it is necessary to adjust the opening diameter of the metal container to match the opening diameter of the lid. This requires, for example, modifying the mold, which is costly and requires improvement. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 3687133 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the object of the present invention is to provide a metal container for reform that can easily change the mouth diameter so that it can be used with lids of various sizes, and a method for manufacturing a lid-fitted metal container by reforming using said metal container for reform. [Means for solving the problem]

[0008] According to the present invention, there is provided a metal container for reform used in the manufacture of lid-fitting type metal containers, characterized in that it has a cylindrical body portion whose lower end is closed and a reform curl portion having an outwardly expanding shape is formed at the upper end of the body portion.

[0009] In the metal container for reform of the present invention, (1) In a side sectional view, the radial width W and the axial length H of the reforming curl portion satisfy the following formula: W > H (1a) or W < H (1b) and are set to satisfy this. (2) The difference (|W - H|) between the radial width W and the axial length H is in the range of 0.1 to 7 mm. (3) The reforming curl portion extends so as not to contact the outer surface of the cylindrical body portion. (4) The radial width W and the axial length H of the reforming curl portion are set to satisfy the formula (1a). (5) When satisfying the formula (1a), the outer diameter D of the upper end of the body portion including the radial width W of the reforming curl portion is smaller than the inner diameter d of the fitting portion of the lid to be fitted and fixed to the reformed metal container. The following means is preferably adopted.

[0010] According to the present invention, further, a reforming metal container as described above is prepared, and there is provided a method for manufacturing a lid - fitting type metal container, characterized in that the radial width W of the reforming curl portion of the reforming metal container is reduced or expanded in diameter so that a metal lid can be put on it.

Effects of the Invention

[0011] The reforming metal container of the present invention has a reforming curl portion formed in an outward - expanding shape. The side sectional shape of this reforming curl portion, for example, has a shape where the radial width W is longer than the axial length H (W > H), or a shape where the radial width W is shorter than the axial length H (W < H). That is, when W > H, the side sectional shape has an elliptical shape with the radial direction as the major axis and the axial direction as the minor axis, and when W < H, it has an elliptical shape with the axial direction as the major axis and the radial direction as the minor axis. As understood from this shape, this reforming curl portion can be reduced in diameter in the radial direction when W > H, and can be expanded in diameter in the radial direction when W < H. Therefore, the metal container for reform of the present invention can change the outer diameter of the curled portion without changing the diameter of its mouth (the diameter of the opening at the top end). In other words, the metal container can be reformed so that the lid can be fitted and fixed without changing the diameter of the mouth of the metal container for each size of lid, which reduces production costs and is suitable for sales of a wide variety of products in small lots. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional side view showing an example of a metal container for reform according to the present invention, showing the entire container together with its lid. [Figure 2] 2 is an enlarged view of a curled portion for reform of the metal container for reform of FIG. 1. FIG. [Figure 3] 1. FIG. 4 is a diagram showing another example of a shape that can be used as the curled portion for reform of the metal container for reform of FIG. [Figure 4] 10A and 10B are diagrams showing other forms of the reform curl portion. [Figure 5] 2 is a diagram for explaining a reforming method using the reforming metal container of the form of FIG. 1. FIG. [Figure 6] 6 is a diagram for explaining a reforming method using the metal container for reform of the form of FIG. 5. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] <Form of metal container for renovation> The metal container for reform of the present invention has a known configuration, except for the specially shaped curled portion.

[0014] As shown in FIG. 1, this metal container for reform, generally designated 10, has a hollow cup shape and includes a hollow body 1. The lower end of body 1 is closed by a bottom 3, which is typically formed of a chime portion 6 that curves from the lower end of body 1 and continues to a ground portion 5, and a bottom surface 7. Of course, the lower end of body 1 can be closed by a flat bottom surface, or the bottom surface can be dome-shaped. When placing the container on an uneven surface, it is advantageous to have a dome-shaped bottom surface 7.

[0015] 1, it is preferable that the upper end opening diameter D0 of the body 1 is set larger than the outer diameter D1 of the lower end of the body 1. This allows the metal containers 10 for reform (hereinafter sometimes simply referred to as "metal containers") to be stacked, which is advantageous for transportation and storage.

[0016] In FIG. 1, the body 1 has an inclined shape with a diameter that decreases downward in consideration of stackability, but it may also have a straight body shape without an inclination, and if necessary, a portion with a reduced diameter may be formed in the upper part of the body 1 by necking-in processing or the like.

[0017] In the metal container 10 having such a configuration, the metal constituting the material may be various metals or alloys, such as aluminum, copper, iron, or alloys containing these metals, or may be a surface-treated steel sheet such as a tin-plated steel sheet or an aluminum sheet subjected to a chemical conversion treatment. Generally, steel, stainless steel, aluminum, or an aluminum alloy is suitable, but aluminum or an aluminum alloy is particularly suitable from the viewpoints of lightness and workability.

[0018] Furthermore, an organic resin coating may be laminated on the inner surface of the metal container 10. The organic resin coating may be a coating derived from paint such as acrylic paint, urethane paint, silicone paint, or fluorine paint, or a thermoplastic resin such as polyethylene terephthalate (PET), which is provided to provide corrosion resistance and to prevent surface roughness during severe molding processes, and is usually a thin film of 50 μm or less. Furthermore, the organic resin coating as described above may be provided on the outer surface of the metal container 10 in order to ensure printing properties, corrosion resistance, and scratch resistance.

[0019] Examples of the thermoplastic resin include polyolefins such as low-density polyethylene, high-density polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, and random or block copolymers of α-olefins such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene; ethylene-vinyl compound copolymers such as ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, and ethylene-vinyl chloride copolymer; styrene resins such as polystyrene, acrylonitrile-styrene copolymer, ABS, and α-methylstyrene-styrene copolymer; polyvinyl compounds such as polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinylidene chloride copolymer, polymethyl acrylate, and polymethyl methacrylate; polyamides such as nylon 6, nylon 6-6, nylon 6-10, nylon 11, and nylon 12; thermoplastic polyesters such as polyethylene terephthalate and polybutylene terephthalate; polycarbonate; polyphenylene oxide; and mixtures thereof. Among these thermoplastic resins, polyester resins are particularly suitable in terms of processability, corrosion resistance, and flavor retention of beverages and the like filled in the container.

[0020] The organic resin coating may be formed in advance on one surface (the surface that will become the inner surface of the container) of the metal raw plate used in forming the metal container 10.

[0021] In the present invention, the upper end of the body 1 is subjected to exterior printing and finishing varnish application and baking, if necessary, followed by curling to form a reform curl portion 9 that extends outward.

[0022] In the present invention, the above-mentioned reforming curl portion 9 is a portion that is reformed to a size that allows the lid 20 (shown as 20 in Figure 1) to be attached to the container 10 to be fitted and fixed in place, depending on the size of the lid.

[0023] As can be seen from the enlarged cross-sectional side view of FIG. 2, the reforming curled portion 9 in FIG. 1 has a shape in which the radial width W is greater than the axial length (height) H. That is, in the example of FIGS. 1 and 2, the reforming curled portion 9 satisfies the following formula (1a): W>H (1a) The curled portion 9 for reforming has an elliptical shape as a whole, with the major axis corresponding to the width W in the radial direction and the minor axis corresponding to the length H in the axial direction.

[0024] For example, as shown in Figure 1, the lid 20 to be attached to the container obtained by reforming a metal container 10 may be made of either plastic or metal. In either case, it has a top plate portion 21 and a cylindrical side wall 23 connected to the top plate portion 21, and may also have a circumferential protrusion 25 extending inward from the lower end of the cylindrical side wall 23. In such a lid 20, when the inner surface of the cylindrical side wall 23 is in close contact with the outer surface of the reformed curled portion 9, the lid 20 is mated and fixed to the reformed metal container, sealing the opening at the top end. That is, the inner diameter of the cylindrical side wall 23 of the lid 20 becomes the mating portion inner diameter d, and the reformed curled portion 9 of the metal container 10 is reformed so that the outer diameter D of the upper end of the metal container 10 matches the mating portion inner diameter d (d = D). Furthermore, when a circumferential protrusion 25 is formed at the lower end of the cylindrical side wall 23 of the lid 20, the lid 20, which is fitted and fixed to the reformed curled portion 9, is more reliably prevented from slipping off. Furthermore, such lids 20 are often made of plastic (for example, polyolefins such as polyethylene and polypropylene, or polyesters such as polyethylene terephthalate), but as already mentioned, they may also be made of metal. If made of plastic, a knob or the like for removing the lid 20 from the reformed curled portion 9 may be provided on the cylindrical side wall 23, and if made of metal, a tear tab with a ring may be provided on the cylindrical side wall 23.

[0025] In the example of Figure 1, the curled portion 9 for reforming of the metal container for reforming 10 satisfies formula (1a), so that the radial width W is large and the outer diameter D of the upper end of the metal container for reforming 10 is larger than the inner diameter d of the mating portion of the metal lid 20 (i.e., D > d). Therefore, in order to fit and secure the lid 20, it is necessary to reduce the radial width W of the curled portion for reforming 9 so that D = d. The greater the length that can be reduced, the wider the range of the inner diameter d of the mating portion of the lid 20 that can be fitted and secured to the upper end of the metal container for reforming 10, and this means that lids 20 of various sizes can be fitted and secured.

[0026] In the present invention, the diameter of the curled portion 9 for reforming can be reduced using a clamping tool capable of compressing it in the circumferential direction. To reduce the diameter without distortion, the tip 9a of the curled portion 9 for reforming preferably extends away from the outer surface of the cylindrical body 1, as shown in FIG. 2. That is, if a large gap CL is formed between the tip 9a of the curled portion 9 and the outer surface of the cylindrical body 1, when the curled portion 9 is compressed from the outside, the tip 9a of the curled portion 9 becomes a free end, and the curled portion 9 is quickly compressed and deformed, for example, by increasing the axial length H and stretching in the height direction, effectively preventing distortion of the shape of the curled portion 9 after reforming. The same applies when expanding the diameter of the curled portion 9 for reforming.

[0027] In the present invention, as shown in FIGS. 1 and 2, the curling portion 9 for reforming described above is usually in the simplest form of an ellipse with the major axis in the radial direction. However, as long as the condition that the radial width W is larger than the axial length (height) H is satisfied, it is not limited to an ellipse. Examples of such other forms are shown in FIG. 3. In FIG. 3(a), it has a wide hook-shaped form, and in FIG. 3(b), it has a flat loop-shaped form. Further, FIG. 3(c) has a shape closer to a rectangle rather than an ellipse. Any of the shapes has W > H, and its tip 9a is separated from the outer surface of the body portion 1.

[0028] Also, the examples shown in FIGS. 1 and 2 described above satisfy the condition (W > H) shown in formula (1a). However, in the present invention, the shape of the curling portion 9 for reforming can also be set to satisfy the condition (W < H) shown in formula (1b). As shown in FIG. 4, such a form of the curling portion 9 for reforming is an ellipse with the major axis in the axial direction, and D < d. Therefore, in this curling portion 9 for reforming, in order to enable fitting and fixing with D = d, it is necessary to expand the diameter of the curling portion 9 for reforming in the radial direction (reduce the diameter in the axial direction). That is, as also described above, in order to easily perform such expansion in the radial direction (reduction in the axial direction), it is preferable that a gap CL is formed between the tip 9a of the curling portion 9 for reforming and the outer surface of the cylindrical body portion 1.

[0029] In the reforming metal container of the present invention described above, when it includes the curling portion 9 for reforming that satisfies the condition (W > H) shown in formula (1a) or the condition (W < H) shown in formula (1b), it is preferable that the difference (|W - H|) between W and H is in the range of 0.1 to 7 mm. Although it depends on the size of the curling portion, the closer this difference is to 0 mm, the smaller the degree of freedom for reducing or expanding the diameter of the curling portion 9 for reforming, and the size of the container lid that can be attached by reforming tends to be limited. Also, if this difference is too large, the deformation work becomes difficult, and it becomes difficult to apply the present invention.

[0030] <Reform Using a Metal Container for Reform> In the present invention, the reform of the curling portion 9 for reform described above is carried out as follows.

[0031] First, for the curling portion 9 for reform in a form (W > H) that satisfies formula (1a), as shown in FIG. 5, the inner surface of the curling portion 9 is fixed in position by the fixed die 51 (FIG. 5(a)), and then by driving the clamp die 53 inward, the outer surface of the curling portion 9 is pressed inward to crush it (FIG. 5(b)). As a result, the curling portion 9 for reform is reduced in diameter in the radial direction (expanded in the axial direction), the outer diameter D of the curling portion, which is larger than the outer diameter d of the container lid 20, is reduced, and D = d, obtaining a metal container provided with a curling portion that enables fitting and fixing of the container lid 20.

[0032] Also, for the curling portion 9 for reform in a form (W < H) that satisfies formula (1b), as shown in FIG. 6, the upper surface of the curling portion 9 is fixed in position by the fixed die 61 (FIG. 6(a)), and then by driving the clamp die 63 upward, the lower side of the curling portion 9 is pressed upward to crush it (FIG. 6(b)). As a result, the curling portion 9 for reform is expanded in diameter in the radial direction (reduced in the axial direction), the outer diameter D of the curling portion, which is smaller than the outer diameter d of the container lid 20, is expanded, and D = d, obtaining a metal container provided with a curling portion that enables fitting and fixing of the container lid 20.

[0033] In the present invention, although it has been described that the container lid for fitting and fixing to the reformed metal container may be made of plastic or metal, usually, plastic is optimal. That is, in the case of a metal container lid, it is difficult to deform, so in order to perform fitting and fixing, it is required to be reformed to a state as close as possible to D = d. Also, the inclination angle of the circumferential protrusion 25 and the like on the container lid 20 are strictly set so that fitting and fixing are easy. However, in the case of a plastic container lid, since it has high flexibility and is easy to deform, the accuracy required for various sizes is low, which is much more advantageous than a metal container lid.

[0034] The metal container obtained by reforming the curled portion 9 for reforming as described above can have a container lid 20 fastened to it, so that it can be filled with various beverages such as beer, fruit juice, etc. and then offered for sale.

[0035] In particular, the present invention can accommodate container closures of various sizes by simply changing the outer diameter of the curled portion, without changing the opening diameter (processed diameter). Therefore, a container production factory can produce and store a large number of metal containers for remodeling, and when selling, remodel them to fit the size of the container closures the customer has, ship the remodeled metal containers (empty containers), and then fill the metal containers with the beverage desired by the consumer, attach and secure the container closure, and sell them to the consumer. This method is particularly suitable for use in convenience stores and the like. [Explanation of symbols]

[0036] 1: Cylindrical body 9: Curl part for reform 9a: Tip of curl 10: Metal container 20: Lid 21:Top plate part 23: Cylindrical side wall 25: Circumferential protrusion 51,61: Fixed type 53,63: Clamp type

Claims

1. A metal container for reform used in the manufacture of lid-fitting type metal containers, characterized in that it has a cylindrical body portion whose lower end is closed and a reform curl portion that expands outward is formed at the upper end of the body portion.

2. In the side cross-sectional view, the radial width W and the axial length H of the curl portion for reforming are expressed by the following formula: W>H (1a) or W<H (1b) 2. The metal container for reform according to claim 1, wherein the metal container is set to satisfy the following:

3. The metal container for reform according to claim 2, wherein the difference (|W-H|) between the radial width W and the axial length H is in the range of 0.1 to 7 mm.

4. 4. The metal container for reform according to claim 1, wherein the curled portion for reform extends so as not to come into contact with the outer surface of the cylindrical body portion.

5. A metal container for reform according to any one of claims 2 to 4, wherein the radial width W and axial length H of the curled portion for reform are set to satisfy the formula (1a).

6. A metal container for reform as described in claim 5, wherein the outer diameter D of the upper end of the body portion, including the radial width W of the curled portion for reform, is smaller than the inner diameter d of the fitting portion of the lid to be fitted and fixed to the reformed metal container.

7. A metal container for reform according to claim 1 is prepared, A method for manufacturing a lid-fitting metal container, characterized in that the radial width W of the curled portion for reform of the metal container for reform is reduced or expanded so that the lid can be placed on it.

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