Metal cup with curling tip

Abstract

This invention provides a metal cup with a curled section that offers improved resistance to deformation under lateral compressive force, and is also suitable for attaching a lid (film) by heat sealing. [Solution] In a metal cup 1 having an opening at its upper end, a curled portion 13 protruding outward is provided around the entire circumference of the upper end opening, and the thickness t of the cup plate at the outermost surface X of the curled portion is 0.1 mm

Description

Technical Field

[0001] The present invention relates to a metal cup with a curled portion formed at the upper end of the opening.

Background Art

[0002] Conventionally, cups made of paper or plastic have been widely used as cup-shaped containers for eating and drinking. Containers formed from these materials are lightweight and easy to mold, so they are inexpensive and suitable for disposable use. However, from the environmental perspective of resource depletion and waste problems in recent years, metal cups have attracted attention. Metal cups are more resistant to stress and more durable than paper or plastic cups, are suitable for repeated use, and can significantly suppress resource depletion and waste generation.

[0003] By the way, metal cups have sharp opening ends and pose a safety problem. After drinking beverages, metal cups are handled very roughly, and the sharp ends often come into contact with the human body. For this reason, a rounded curled portion is formed at the upper end of the metal cup so that the sharp end does not touch the human body (see, for example, Patent Document 1).

[0004] However, the above-mentioned curled portion is weak against lateral compressive forces and has the problem of being easily deformed. For example, it may be deformed even when the curled portion is strongly grasped. In addition, a metal cup provided with such a curled portion is not suitable for attaching a lid material by heat sealing, and is restricted in the sales form after filling with contents such as beverages. Since the lid material is not attached, it becomes difficult to take it home after purchase.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Therefore, an object of the present invention is to provide a metal cup with a curled portion having improved deformation resistance against lateral compressive force and suitable for attaching a lid material (film) by heat sealing.

Means for Solving the Problems

[0007] According to the present invention, in a metal cup having an opening formed at the upper end, a curled portion protruding outward is provided over the entire circumference of the upper end opening, and the cup plate thickness t at the outermost surface portion of the curled portion satisfies the condition of 0.1 mm < t < 0.3 mm, and a flat portion is formed on the upper surface of the curled portion. A metal cup is provided.

[0008] In the metal cup of the present invention, (1) the width W1 of the flat portion is in the range of 30 to 70% with respect to the width W0 of the curled portion, (2) the width W0 of the curled portion is in the range of 3 to 15 mm, and the depth d of the curled portion is in the range of 1 to 5 mm, is preferable.

Effects of the Invention

[0009] In the metal cup of the present invention, since the plate thickness of the outermost surface portion of the curled portion is set thick, it has high deformation resistance against lateral compressive force, and the formation of sharp portions is prevented due to the deformation of the curled portion, so the safety is high. In addition, the curled portion of this metal cup has a flat portion, so it is also suitable for attaching a film by heat sealing, and after filling the contents, the lid material can also be attached by heat sealing and sold.

Brief Description of the Drawings

[0010] [Figure 1] This is a schematic side cross-sectional view showing the overall form of the metal cup of the present invention. [Figure 2] A magnified cross-sectional view of the curled portion of the metal cup shown in Figure 1. [Modes for carrying out the invention]

[0011] In Figure 1, the metal cup of the present invention, shown as 1 overall, consists of a cylindrical body portion 3 with an open upper end and a bottom portion 5 that closes the lower end of the cylindrical body portion 3. The bottom portion 5 may be flat, but it usually has an annular contact portion 7, the outer side of which is connected to the lower end of the cylindrical body portion 3 by a bent charm portion 9, and the inner side of which is raised. Having the bottom portion 5 in this form allows the metal cup 1 to be held in a more stable position (upright position).

[0012] Furthermore, to ensure stackability, it is preferable that the upper opening diameter D0 of the cylindrical body 3 is set to be larger than the outer diameter D1 of the lower end of the cylindrical body 3, as shown in Figure 1. This allows empty metal cups 1 to be stacked, which is advantageous for transportation and storage.

[0013] In a metal cup 1 of this form, the constituent metal material may be various metals or alloys, such as aluminum, copper, iron, or alloys containing these metals, or surface-treated steel sheets such as tin-plated steel sheets or chemically treated aluminum sheets. Generally, steel, stainless steel, aluminum, or aluminum alloys are preferred, but aluminum or its alloys are particularly preferred from the viewpoint of lightness and workability.

[0014] Furthermore, the inner surface of the metal cup 1 may be laminated with an organic resin coating. The organic resin coating is a coating derived from paints such as acrylic paints, urethane paints, silicone paints, and fluorine paints, or a thermoplastic resin such as polyethylene terephthalate (PET). It is provided to suppress corrosion and surface roughness during severe molding processes. Usually, it is a thin film of 20 μm or less. Also, the above-mentioned organic resin coating may be provided on the outer surface of the metal cup 1 in order to ensure printing characteristics, corrosion resistance, and scratch resistance.

[0015] Referring to the partial enlarged view of FIG. 2 together with FIG. 1, in the metal cup 1 of the above-described form, a curled portion 13 that protrudes outward is formed over the entire circumference at the upper end of the cylindrical body portion 3. That is, by forming such a curled portion 13, it is effectively prevented that the sharp end portion 13a made of metal comes into contact with the human body.

[0016] In the present invention, the cup plate thickness t at the outermost surface portion X of the curled portion 13 satisfies the condition of 0.1 mm < t < 0.3 mm. That is, a normal known metal cup is subjected to ironing processing in addition to drawing processing, and ironing processing involving thinning is performed in one or a plurality of stages. As can be understood from this, in the metal cup obtained through ironing processing, the plate thickness t at the outermost surface portion X is considerably thick. By making the outermost surface portion X thick in this way, high deformation resistance against lateral compressive force can be ensured.

[0017] For example, if the plate thickness t is thinner than the above range, it becomes easily deformed against the lateral compressive force. For example, it will be deformed even when the curled portion 13 is gripped slightly strongly. Also, if the plate thickness t exceeds the above range and becomes thick, although the strength itself increases, thinning is greatly restricted, ironing processing is restricted, and inconveniences such as the height H of the metal cup 1 becoming small occur.

[0018] Furthermore, the plate thickness t0 at the center O of the bottom portion 5 corresponds to the thickness of the base material used for forming the metal cup 1. Therefore, in terms of the balance between thinning and the strength of the curled portion 13, it is preferable that the cup plate thickness t at the outermost surface portion X of the curled portion 13 is in the range of 50 to 80% of the plate thickness t0 (i.e., the thickness of the base material). Also, in terms of facilitating the drinking of the beverage contained in the metal cup 1, it is suitable that the height H of the metal cup 1 is in the range of about 100 to 200 mm.

[0019] Furthermore, in the present invention, it is important that a flat portion 17 is formed on the upper surface of the curled portion 13. By forming such a flat portion 17, it becomes possible to attach a heat-sealing lid material. If the flat portion 17 is not provided, it is difficult to perform heat-sealing pressure bonding by a heat-sealing bar. However, by providing the flat portion 17, the pressure-bonding area by the heat-sealing bar becomes larger, so that it becomes possible to attach the heat-sealing lid material. As the heat-sealing lid material, as long as it is a film of a heat-sealable thermoplastic resin, its material is not limited. Generally, films of polyesters such as olefin-based resins and polyethylene terephthalate (PET) are preferably used.

[0020] In the present invention, it is preferable that the width W1 of the flat portion 17 is in the range of 30 to 70%, particularly about 40 to 60%, with respect to the overall width W0 of the curled portion 13. If the ratio of this width W1 is small, heat-sealing tends to be difficult, and also, molding (molding of the curled portion 13) may become difficult. Also, if the ratio of the width W1 is too large, it is likely to cause a decrease in the strength of the curled portion 13. Furthermore, as understood from FIG. 2, the overall width W0 of the curled portion 13 means the distance between the inflection point Q generated between the inner side portion of the curled portion 13 and the upper end of the cylindrical end portion 3, and the outermost surface portion X of the curled portion 13.

[0021] Furthermore, in this invention, in order to maximize the lateral and vertical strength of the curled portion 13 without impairing the heat-sealing properties of the flat portion 17 described above, it is preferable that the overall width W0 of the curled portion 13 is in the range of 3 to 15 mm and the depth d is in the range of 1 to 5 mm. That is, if the width W0 or depth d is excessively large or excessively small, the lateral strength and vertical strength tend to decrease.

[0022] Such a metal cup 1 is formed by punching and drawing a thin metal sheet (the inner surface may have the aforementioned organic resin coating) to create a bottomed cylindrical body with a horizontal flange larger than the aforementioned width W0 at its upper end. Then, while holding this horizontal flange, it is redrawn and ironed, and if necessary, the redrawing is repeated multiple times. Next, the bottom is domed to obtain a cup in which a horizontal flange is formed in place of the curled portion 13. After washing and drying this cup, if necessary, an organic resin coating is formed on the outer surface by baking an outer paint, applying and baking a finish varnish, etc. Furthermore, if an organic resin coating is formed with paint, the outer paint is applied and baked, and finally, the horizontal flange portion is curled to obtain the metal cup 1 of the present invention with a curled portion 13. In addition, when forming the flat portion 17, the manufacturing method is not limited to the above method. A bottomed cylindrical body with a horizontal flange larger than the width W0 described above may be formed, then a portion of this horizontal flange flat may be curled to form the flat portion 17, and then, while holding the flat portion 17, a redrawing-drawing process may be performed.

[0023] The metal cup 1 of the present invention described above has a curled portion 13 that is resistant to deformation and is suitable for use as a beverage cup sold at events such as sporting events. Furthermore, since the curled portion 13 is provided with a flat portion 17, it is possible to fill the container with contents such as beverages, then attach a lid by heat sealing and sell the product. For example, chilled beverages such as lactic acid drinks, which are filled into containers at a low temperature of 5°C or below, stored at a low temperature of 10°C or below, and consumed within a short period of time, can be filled into the metal cup 1 described above, and then sold with a heat-seal lid attached. [Explanation of Symbols]

[0024] 1: Metal cup 3: Torso 5: Bottom 7: Grounding part 13: Curl section 17: Flat section

Claims

1. In a metal cup having an opening formed at its upper end, A metal cup characterized in that a curled portion protruding outward is provided around the entire circumference of the upper end opening, the cup plate thickness t at the outermost surface of the curled portion satisfies the condition 0.1 mm < t < 0.3 mm, and a flat portion is formed on the upper surface of the curled portion.

2. The width W of the curled portion ０ In contrast, the width W of the flat portion １ A metal cup according to claim 1, wherein the percentage is in the range of 30-70%.

3. The width W of the curled portion ０ The metal cup according to claim 2, wherein the length is in the range of 3 to 15 mm, and the depth d of the curled portion is in the range of 1 to 5 mm.

Images