JP6875812B2 - Aluminum foil molding container - Google Patents

Description

The present invention relates to an aluminum foil molded container in which food is stored inside the container and the food can be cooked and eaten by heating the container as it is. More specifically, the present invention refers to stacking (stacking a plurality of containers vertically). The same shall apply hereinafter.) The present invention relates to an aluminum foil molded container that is easy to use and has good heating efficiency when used for heating with an electromagnetic cooker.

A food package containing foods such as noodles and pots in an aluminum foil molding container (including an aluminum alloy foil molding container; the same applies hereinafter) can be cooked and eaten as it is without being transferred to a separate container. It is convenient because the container can be thrown away after eating, and it is widely used as it is sold at convenience stores.
In the past, it was common to heat these food packages over a direct fire by putting them on a gas stove or the like, but in recent years, electromagnetic cookers have rapidly become widespread due to fire safety and other factors. Therefore, there is a demand for food packaging that can be cooked with an electromagnetic cooker.

The principle of heating a food package by such an electromagnetic cooker is as follows. When an alternating current is passed through a coil built into an electromagnetic cooker and a food package is placed on it, electromagnetic induction occurs due to changes in the magnetic field lines, and the bottom surface of the aluminum foil molded container of the food package is in a direction that prevents changes in the magnetic field lines. Eddy current is generated in.
When this eddy current flows through an aluminum foil molded container, Joule heat is generated by the electrical resistance of the metal that is the material of the container, and the food stored in the container is heated (for example, Patent Document 2). (See paragraph 0002 and paragraph 0003 of the same paragraph).

Various attempts have been made to improve the efficiency of cooking for food packages that can be cooked by an electromagnetic cooker.
For example, Patent Document 1 discloses an aluminum alloy foil-molded container having a predetermined alloy composition, thickness, and average crystal grain size, and a food package. By changing the alloy composition of the aluminum alloy as a material in this way. By changing the specific resistance value of the alloy, the efficiency of cooking by the electromagnetic cooker is improved.
Further, in Patent Document 2, an aluminum foil molding container for electromagnetic cooking has a bottom portion having a predetermined area, embossing is formed at a predetermined ratio with respect to the bottom area, and has a predetermined alloy composition. It is disclosed that, in addition to the change in alloy composition, the bottom of the container has an area within a predetermined range and the bottom of the container is embossed in a predetermined ratio or more, so that the cooking is cooked by an electromagnetic cooker. Is improving the efficiency of.

Japanese Unexamined Patent Publication No. 2009-97077 Japanese Unexamined Patent Publication No. 2003-153802

Generally, in order to increase the heating efficiency of the aluminum foil molding container by the electromagnetic cooker, it is conceivable to increase the area of the bottom of the aluminum foil molding container that is in direct contact with the electromagnetic cooker. If the area of the bottom of the aluminum foil molded container is too large, the display space becomes too large, which is not preferable.
Therefore, in order to increase the area of the bottom without changing the size of the entire aluminum foil molding container, the side wall of the aluminum foil molding container may be in a state close to vertical, but in that case, a plurality of aluminum foil molding containers are stacked. At that time, the side walls of the aluminum foil molded containers located above and below are more likely to interfere with each other as compared with the case where the side walls are inclined, and the height at the time of stacking becomes high.
As a result, there are problems that the handling of the container during production is deteriorated and the efficiency of container packaging during container transportation is deteriorated.

Therefore, the problem to be solved by the present invention is to achieve both the heating performance by the electromagnetic cooker and the stacking performance of the aluminum foil molded container.

Through diligent studies, the present inventors have solved the above problem by forming the side wall of the aluminum foil molded container into a convex shape (curved shape) inside the container.
More specifically, the aluminum foil molded container according to the invention is connected to the bottom wall and the peripheral edge of the bottom wall, and is connected to the side wall rising from the peripheral edge and the entire circumference of the upper end opening of the side wall. A flange extending substantially horizontally from the opening and a cylindrical edge winding connected to the outer circumference of the flange are provided, and the side wall is arranged from a side close to the bottom wall to a side close to the opening. The thickness is gradually increased toward the surface, and the shape is convex inward from the straight line connecting the intersection of the side wall and the flange and the intersection of the side wall and the bottom wall.

Generally, in the side wall of an aluminum foil molded container molded by press working, when comparing the region near the opening and the region near the bottom wall, the side wall of the region near the opening (first region). The thickness of is larger than the thickness of the side wall of the region (second region) near the bottom wall.
This is because when an aluminum foil blank is formed into a container by press molding, the center of the blank becomes the bottom wall and the peripheral edge of the blank becomes the side wall, but the peripheral edge of the blank that rises during pressing to form the side wall. This is because the amount of narrowing down during pressing increases as the distance from the bottom wall increases. Therefore, the wrinkles generated on the side wall become larger as the distance from the bottom wall increases, and the thickness of the first region of the side wall formed by folding the wrinkles becomes larger than the thickness of the second region.
When the side wall is convex inward from the straight line connecting the intersection of the side wall and the flange and the intersection of the side wall and the bottom wall, the rising angle of the second region with respect to the bottom wall is naturally relatively large, and the first region The rising angle with respect to the bottom wall is naturally relatively small (the rising angle refers to the angle formed by the bottom wall and the side wall on the outer surface side of the container in the second region, and in the first region, the side wall to be described later. The angle formed by the straight line passing through the formed bent portion and parallel to the bottom wall and the side wall, which is the angle on the outer surface side of the container. The same shall apply hereinafter).
Interference during stacking can be suppressed by making the rising angle of the first region relatively small, which is relatively thick and easily interferes when stacking, and by leaving the first region in a so-called laid state. it can.
In addition, by increasing the rising angle of the second region, which is relatively small in thickness and less likely to interfere when stacking, and making the second region upright, the entire side wall becomes like the first region. The area of the bottom wall can be increased if the area of the opening is constant, as compared with the case where the rising angle is small. Therefore, it is possible to improve the heating efficiency when the aluminum foil molded container is placed in an electromagnetic cooker.
In this way, the bottom area is large and the heating efficiency can be improved as compared with the container in which the rising angle of the entire side wall is the same as that in the first region, and the rising angle of the entire side wall is compared with the container in the second region. , Interference on the side wall can be suppressed and stacking performance can be improved.
That is, according to the aluminum foil molded container of the present invention, both heating performance and stacking performance can be achieved at the same time.

In the aluminum foil molded container according to the present invention, the side wall has a bent portion on the entire circumference in the middle of the rising direction from the bottom wall toward the opening, and the side wall above the bent portion is below the bent portion. It is preferable that the side wall is bent outward and stands up.

In the aluminum foil molded container according to the present invention, the straight line connecting the intersection of the side wall and the flange, the intersection of the side wall and the bottom wall, and the maximum distance to the side wall are 0.3 mm or more and 5.0 mm or less. preferable.
Similarly, in the aluminum foil molding container according to the invention, the thickness of the aluminum foil used as the material is t, the diameter of the edge winding is c, the angle formed by the inward extension line of the flange and the side wall is θ ₁ , and the bottom. When the angle between the wall and the side wall is θ ₂ , 7t << | c · cos θ ₁ | (however, 65 ° ≤ θ ₁ ≤ 85 °) and 4.5t << | c · cos θ ₂ | (however, 95 °). ≤θ ₂ ≤110 °) is preferably satisfied. In this case, it is still preferable that 70 μm ≦ t ≦ 100 μm and 2.5 mm ≦ c ≦ 4.5 mm.
The aluminum foil molding container according to the invention can be suitably used as an aluminum foil molding container for an electromagnetic cooker.

Since the aluminum foil molded container according to the invention is configured as described above, it is possible to achieve both the heating performance and the stacking performance of the electromagnetic cooker.

Perspective view of the aluminum foil molded container of the embodiment (A) is a plan view and (b) is a vertical sectional view of the aluminum foil molded container of the embodiment. Enlarged vertical cross-sectional view of the main part of the aluminum foil molded container of the embodiment Enlarged vertical cross-sectional view of a main part showing a state in which the aluminum foil molded containers of the embodiment are stacked. Longitudinal section showing another example of the aluminum foil molded container of the embodiment

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, in the aluminum foil molded container 10 of the embodiment, a side wall 12 rising from the peripheral edge of the bottom wall 11 is continuously provided on the substantially circular bottom wall 11. Further, flanges 13 are continuously provided on the entire outer circumference of the upper end opening 12a of the side wall 12 in a direction substantially parallel to the bottom wall 11. Further, a cylindrical edge winding 14 is continuously provided over the entire outer circumference of the flange 13.
The container 10 can be manufactured by integrally molding (press molding) an aluminum foil using male and female dies. A large number of wrinkles (not shown) are formed on the side wall 12 of the aluminum foil molded container manufactured in this manner, and the thickness of the side wall 12 is defined by overlapping the wrinkles. The thickness of the side wall 12 gradually increases from the side of the bottom wall 11 toward the side of the opening 12a. As described above, this is derived from press molding.

The thickness of the aluminum foil used for press molding of the container 10 is not particularly limited, but is preferably 70 μm to 100 μm, and particularly preferably 80 μm to 95 μm. If it is less than 70 μm, the strength required for a molded container cannot be obtained, and if it exceeds 100 μm, processing into a molded container may become difficult.
Further, when used as a container for an electromagnetic cooker, the electric resistance usually decreases as the thickness of the aluminum foil increases. Therefore, if the thickness exceeds 100 μm, the electric resistance becomes too small and the container may not be used for electromagnetic cooking.

The diameter of the edge winding 14 of the container 10 may be 2.5 mm to 4.5 mm, and is particularly preferably 3.0 mm to 4.0 mm. If the diameter is less than 2.5 mm, the diameter is too small, and when stacking, the bottom walls and side walls of the upper and lower containers will come into contact with each other before the rims of the upper and lower containers come into contact with each other, providing the required stacking performance. In addition to the possibility that it cannot be obtained, the aluminum foil may be crushed during molding because the diameter of the edge winding is too small, and the strength of the foil is too high with respect to the diameter of the edge winding. May be difficult to mold. On the other hand, if the diameter exceeds 4.5 mm, the large-diameter rims of the upper and lower containers come into contact with each other when stacked, so that the stacking height of the containers may become higher than necessary.

A plurality of embossed portions 11a are formed on the bottom wall 11 concentrically with the bottom wall 11. The area of the bottom wall 11 is not particularly limited, but is preferably ^{80 to 300 cm 2.} If the bottom area is less than 80 cm ^2, and is too small area of the bottom wall decreases the heating efficiency by the electromagnetic cooker, may become disabled cooking by induction heating cooker exceeds 300 cm ^2, the area of the bottom wall Is too large and the display space is too large, which is not preferable.

As shown in FIGS. 1 and 2, the side wall 12 has a bent portion 12b in the middle of the rising direction from the bottom wall 11 toward the upper end opening 12a. The side wall 12 above the bent portion 12b bends toward the outside of the container and stands up from the side wall 12 below the bent portion 12b. That is, the rising angle of the side wall 12 above the bent portion 12b is smaller than the rising angle of the side wall 12 below the bent portion 12b. The bent portion 12b is continuously formed around the entire circumference of the side wall of the container in the circumferential direction.
As shown in FIG. 3, the side wall 12 is bent inward by the bent portion 12b so as to be convex inward of the container from the straight line L connecting the intersection of the flange and the side wall and the intersection of the side wall and the bottom wall. It has a shape. That is, the side wall 12 is located inside the straight line L.
Of the distance between the straight line L and the side wall 12 (the length of the perpendicular line drawn from the side wall 12 to the straight line L), the farthest distance d (in the embodiment, the distance between the bent portion 12b of the side wall 12 and the straight line L). ) May be 0.3 mm to 5.0 mm, and particularly preferably 0.3 mm to 3.1 mm.
If the distance is less than 0.3 mm, there is no significant difference in comparison with the conventional container in which the side wall rises linearly from the bottom wall, and the stacking performance required for the container 10 may not be obtained. Further, if the distance exceeds 5.0 mm, the side wall 12 may be broken toward the inner surface side of the container when a force is applied to the container, and when the containers are stacked, between the side walls of the upper and lower containers. A relatively large gap is created, and it is easy to shake due to vibration during transportation, and the stacking state may not be stable.

The side wall 12 is formed with ribs 12c extending in the vertical direction on the entire circumference thereof. The area of the opening 12a of the side wall 12 is not particularly limited, but it is preferably ^{120 to 400 cm 2 as the storage performance of the contents is good.}

In the present invention, it has been found that the stacking performance becomes more preferable when the following relational expressions (formula (I) and formula (II)) are simultaneously satisfied in order to solve the above-mentioned problem of stacking performance.
7t << | c · cos θ ₁ ｜ ・ ・ ・ ・ ・ Equation (I)
4.5t << | c · cos θ ₂ | ・ ・ ・ Equation (II)
[T: Aluminum foil thickness, c: Edge winding diameter, θ ₁ : Angle between the extension line of the flange to the inside of the container and the side wall, θ ₂ : Angle between the bottom wall of the container and the side wall of the container]
_{Here, θ 1} of the formulas (I) and (II) needs to be 65 ° to 85 °, preferably 70 ° to 78 °. If the angle is less than 65 °, the capacity of the container required for use as a container for an electromagnetic cooker and the heating efficiency required for electromagnetic cooking cannot be obtained, and if the angle exceeds 85 °, the stacking required for the container is not obtained. I can't get the performance.
_{Θ 2} of the formulas (I) and (II) needs to be 95 ° to 110 °, preferably 97 ° to 100 °. If the angle is less than 95 °, the stacking performance required for the container cannot be obtained, and if the angle exceeds 110 °, the capacity of the container required when used as a container for an electromagnetic cooker and the heating efficiency required for electromagnetic cooking can be obtained. I can't.

The derivation of equations (I) and (II) is as follows.
First, referring to FIG. 3, the thickness of the region above the bent portion 12b (first region) and the region below the bent portion 12b (second region) of the side wall 12 is the thickness of the aluminum foil which is the material of the container. Using the thickness t of the material, it can be approximated to "7t" and "4.5t", respectively.
Here, in the aluminum foil molded container formed by press molding, the thickness of the side wall 12 including the wrinkles is thinner in the lower region (second region) than in the upper region (first region) of the bent portion. This is as described above.
Although it depends on the shape of the container to be molded, the thickness is not usually constant in each of the first region and the second region, and the thickness of the side wall gradually increases from the lower side to the upper side. As a result of repeating the measurement, it was found that the side wall thickness of the first region was "7t" at the maximum and the side wall thickness of the second region was "4.5t" at the maximum. Approximated. In FIG. 3, the difference in thickness between the first region and the second region is schematically expressed by the difference in the thickness of drawn lines.
In the embodiment, the bent portion 12b divides the first region and the second region, but as will be described later, in the aluminum foil molded container of the present invention, the side wall 12 is the side wall 12 and the flange 13. It suffices if the intersection is convex inward from the straight line connecting the intersection of the side wall 12 and the bottom wall 11, and it is not always necessary to have a clear bent portion 12b. If there is no clear bent portion 12b, the point where the perpendicular line drawn from the side wall 12 to the straight line L at the above-mentioned distance d intersects the side wall can be regarded as the bent portion. Including the case where such a clear bent portion 12b is not provided, the second region of the side wall is the vertical height of the entire side wall due to the above circumstances that the thickness of the side wall increases from the lower side to the upper side. It refers to the region of 45% or less, and the first region of the side wall refers to the remaining region. If the upper limit of the vertical height of the entire side wall is within the range of 20 to 45% of the vertical height of the entire side wall, the efficiency of cooking by the electromagnetic cooker and the stacking performance can be compatible at a high level.

Here, referring to FIG. 4, when the containers are stacked and the edge windings 14 of the upper and lower containers 10 are in contact with each other, the distance (thickness) formed by the first regions on the side walls 12 of the upper and lower containers 10 is formed. The distance between the virtual centers in the direction) can be expressed as _{"| c · cos θ 1 |".} If this "| c · cos θ ₁ |" is larger than the thickness "7t" of the side wall 12 of the first region, there is a gap between the side walls in the first region of the vertically located containers when the containers are stacked. Therefore, the side walls 12 in the first region do not interfere with each other.
Similarly, when the edge windings 14 of the upper and lower containers 10 are in contact with each other, the distance formed by the second regions on the side walls 12 of the upper and lower containers 10 (distance between virtual centers in the thickness direction) is It can be expressed as “| c · cos (180 ° −θ ₂ ) |” = “| c · cos θ _{2 |”.} If this "| c · cos θ ₂ |" is larger than the thickness "4.5 t" of the side wall 12 of the second region, there is a gap between the side walls of the vertically located containers in the second region when the containers are stacked. The side walls 12 in the second region do not interfere with each other because of the existence of.
Therefore, by satisfying both the formula (I) and the formula (II), the entire side walls 12 of the upper and lower containers 10 do not interfere with each other during stacking, and good stacking performance can be obtained.
In addition, in FIG. 4, the maximum state (a state in which the thickness 7t of the first region and the thickness 4.5t of the second region substantially coincide with _{| c · cosθ 1} | and | c · cosθ _{2 |, respectively) is schematically illustrated.} It is expressed as a target.

Further, when used as a container for an electromagnetic cooker, the alloy composition of aluminum suitable for obtaining high heating efficiency is, for example, 0.5 ≦ Mn ≦ 3.0% by mass of Mn and 0.0001 ≦ Cr < 0.20% by mass of Cr, 0.2≤Mg≤1.8% by mass of Mg, 0.0001≤Ti≤0.6% by mass of Ti, and 0 <Cu≤0.005% by mass of Cu An aluminum alloy containing 0 <Si ≦ 0.1% by mass of Si and 0 <Fe ≦ 0.2% by mass of Fe, the balance of which is aluminum and unavoidable impurities.
With such an alloy composition, an aluminum foil molded container that can be efficiently heated by an electromagnetic cooker can be manufactured by having an electrical resistivity value of a certain level or higher, and therefore, it can be preferably used.

Hereinafter, the content of the invention will be further clarified by giving examples and comparative examples of the present invention.
In the containers of Examples 1 to 10 and Comparative Examples 1 to 3, a substantially circular bottom wall and a side wall rising from the peripheral edge of the bottom wall are continuously provided. Further, a flange is continuously provided on the entire outer circumference of the upper end opening of the side wall in a substantially horizontal direction with the bottom wall. Further, a cylindrical edge winding is continuously provided over the entire outer circumference of the flange. The container is manufactured by integrally molding (press molding) aluminum foil using male and female dies. The bottom wall is concentrically embossed from the center of the bottom wall of the container.
These configurations are the same as those of the aluminum foil molded container 10 of the embodiment.

Further, in Examples 1 to 10, the side wall has a bent portion in the middle of the rising direction from the bottom wall toward the upper end opening, similarly to the side wall 12 of the aluminum foil molding container 10 of the embodiment.
The side wall above the bent portion bends toward the outside of the container and rises from the angle of the side wall rising upward from the bottom wall. This bent portion is continuously formed on the entire circumference of the side wall of the container in the circumferential direction. The side wall has a convex shape inside the container with respect to a straight line connecting the intersection of the flange and the side wall and the intersection of the side wall and the bottom wall.
On the other hand, in Comparative Examples 1 and 2, unlike the side wall 12 of the aluminum foil molded container 10 of the embodiment, the side wall rises linearly from the bottom wall toward the upper end opening.
Further, in Comparative Example 3, unlike the side wall 12 of the aluminum foil molded container 10 of the embodiment, the side wall has a bent portion in the middle of the rising direction from the side wall toward the upper end opening, but the bending direction thereof. Is the opposite of that of Examples 1-10.
That is, the side wall above the bent portion bends toward the inside of the container and rises from the angle of the side wall rising upward from the bottom wall. This bent portion is continuously formed on the entire circumference of the side wall of the container in the circumferential direction. The side wall has a convex shape (concave shape inward) on the outside of the container with respect to a straight line connecting the intersection of the flange and the side wall and the intersection of the side wall and the bottom wall.

The alloy composition of the containers of Examples 1 to 10 and Comparative Examples 1 to 3, the area of the plane with the opening edge of the container as the outer circumference, the height of the container, the shape of the blank before press molding, and the container opening after press molding. The shape, the shape of the bottom of the container after press molding, etc. are the same.
Here, the alloy composition is 1.6% by mass of Mn, 1.0% by mass of Mg, 0.003% by mass of Ti, 0.03% by mass of Si, and 0.05% by mass of Fe. , 0.0002% by mass Cr and 0.0004% by mass Cu are contained, and the balance is composed of aluminum and unavoidable impurities. The shape of the blank before press molding is circular, and the shape of the opening and bottom after press molding is circular and has ribs.

Further details of Examples 1 to 10 and Comparative Examples 1 to 3 are shown in Table 1 below.
Table 1 shows the area of the plane with the edge of the opening as the outer circumference (mouth area), the height of the side wall of the container excluding the edge winding (side wall height), and the vertical height from the bottom wall to the bent part. (Bent height), thickness of aluminum foil (t) of material, edge winding diameter (c), corner of the extension line of the flange of the container and the side wall of the container, the corner on the inner surface side of the container (θ1), the container Of the corners formed by the bottom wall and the side wall of the container, the corner (θ2) of the inner surface of the container, the intersection of the flange and the side wall, and the straight line connecting the intersections of the side wall and the bottom wall, one of the vertical lines drawn from the side wall. The distance (d) apart, the bottom area of the container after molding, and the diameter of the blank before molding are shown.

The method for measuring the height of the container and the height of the bent portion is not particularly limited, but it can be measured with an arbitrary height measuring instrument.
Further, the method for measuring the thickness (t) of the aluminum foil of the material is not particularly limited, but it can be measured with an arbitrary thickness measuring device.
The method for measuring the edge winding diameter (c) is not particularly limited, but it can be measured with an arbitrary thickness measuring device, calipers, or the like.
Further, the method of measuring the distance (d) that is the farthest from the vertical line drawn from the side wall with respect to the straight line connecting the intersection of the flange and the side wall and the intersection of the side wall and the bottom wall is not particularly limited, but is arbitrary. It can be measured with a point micrometer or a bispherical micrometer.

<Test 1: Evaluation test of stacking performance>
The height of stacking 10 containers of Examples 1 to 10 and Comparative Examples 1 to 3 in each container alone was measured, and the stacking performance was compared. The results are shown in Table 2. In Table 2, the x mark indicates that stacking was not possible.
<Test 2: Description of IH efficiency evaluation test method>
Put 500 ml of water at 25 ° C in the containers of Examples 1 to 10 and Comparative Examples 1 to 3, and use an electromagnetic cooker (Toshiba MR-101, 1200 W) to heat the stored water to 80 ° C. Was measured. The results are shown in Table 2.
As can be seen from Table 2, good stacking performance and good heating performance were obtained in all of Examples 1 to 10, whereas in Comparative Examples 1 to 3, either stacking performance or heating performance was obtained. One was inadequate.

It should be considered that the embodiments and examples disclosed this time are exemplary in all respects and not restrictive. The scope of the invention is indicated by the claims and is intended to include all modifications and modifications within that scope.

In the aluminum foil molded container of the present invention, the bottom wall may or may not be embossed. When the bottom wall is embossed, its shape is not particularly limited.
The rib processing of the side wall may or may not be performed. When the side wall is ribbed, its shape is not particularly limited.
The aluminum foil molded container of the present invention is suitable for cooking with an electromagnetic cooker, but it goes without saying that it can also be used for cooking with an open flame such as a gas stove.

In the embodiment of the present invention, the aspect in which the bent portion 12b is clearly formed on the side wall is shown, but the present invention is not limited to this aspect, and the shape of the side wall is the intersection of the flange 13 and the side wall 12 as shown in FIG. The shape may be convex inward of the container 10 with respect to the straight line L connecting the intersections of the side wall 12 and the bottom wall 11, and the shape may be curved without clearly having a bent portion.
Further, the height of the bent portion 12b is not particularly limited, but the vertical height from the bottom of the boundary portion between the first region and the second region of the side wall is 20 of the vertical height of the entire side wall as described above. Since it is preferably in the range of% to 45%, the height of the bent portion 12b that separates the first region and the second region is also preferably a corresponding height.

The shape of the container opening and the shape of the bottom wall when viewed in a plan view from the opening side of the aluminum foil molded container are not particularly limited, and may be a round shape, a square shape, a polygonal shape, or the like.
In the examples, the aluminum foil molded container of the present invention is made of an aluminum alloy having a specific composition, but the composition is not particularly limited.

10 Aluminum foil molded container 11 Bottom wall 11a Embossed portion 12 Side wall 12a Opening 12b Bending portion 12c Rib 13 Flange 14 Edge winding L Straight line d straight line L connecting the intersection of the flange and the side wall and the intersection of the side wall and the bottom wall Maximum distance from the side wall t Thickness of aluminum foil θ ₁ Angle between the extension line of the flange to the inside of the container and the side wall θ ₂ Corner between the bottom wall of the container and the side wall of the container

Claims (4)

With a nearly circular bottom wall,
A side wall that is connected to the peripheral edge of the bottom wall and rises from the peripheral edge,
A flange that is connected to the entire circumference of a substantially circular opening at the upper end of the side wall and extends substantially horizontally from the opening.
A cylindrical rim winding, which is continuously provided on the outer circumference of the flange, is provided.
The side wall
The thickness gradually increases from the side close to the bottom wall toward the side close to the opening, and is inward from the straight line connecting the intersection of the side wall and the flange and the intersection of the side wall and the bottom wall. It has a convex shape and has a convex shape.
The side wall has a bent portion continuous with the entire circumference in the rising direction from the bottom wall toward the opening.
The side wall in the first region above the bent portion bends outward from the side wall in the second region below the bent portion and rises.
The maximum thickness of the side wall in the first region is t ₁ , the maximum thickness of the side wall in the second region is t ₂ , the diameter of the edge winding is c, the inward extension line of the flange and the first region of the side wall. When the angle formed _{by the two is θ 1} , and the angle formed by the bottom wall and the second region of the side wall is θ ₂ ,
An aluminum foil molded container satisfying _{t 1} << | c · cos θ ₁ | (where 65 ° ≤ θ ₁ ≤ 85 °) and t ₂ << | c · cos θ ₂ | (where 95 ° ≤ θ _{2 ≤ 110 °).} The aluminum foil molding container according to claim 1, wherein the straight line connecting the intersection of the side wall and the flange, the intersection of the side wall and the bottom wall, and the maximum distance to the side wall are 0.3 mm or more and 5.0 mm or less. .. The aluminum foil molded container according to claim 1 or 2, wherein 2.5 mm ≦ c ≦ 4.5 mm. The aluminum foil molded container for an electromagnetic cooker according to any one of claims 1 to 3.

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