JP6970558B2 - Metal leaf molding container - Google Patents

Description

The present invention relates to a metal leaf molded container.
More specifically, the present invention relates to a metal leaf molded container that improves the strength of the boundary between the bottom wall and the peripheral wall and suppresses the perforation generated by the repeated deformation of the boundary between the bottom wall and the peripheral wall.

A food package is known in which food such as udon is stored in a wrinkled metal foil-molded container made by press-molding a metal foil such as aluminum foil. This type of food package is convenient and widely distributed because the container can be easily cooked on a gas stove and the container can be disposable after meals.
The food manufacturer stores the food in the metal leaf molded container. When the metal leaf molded container containing this food is delivered from the food manufacturer to the retail store, or when the consumer is taken home from the retail store, the food stored in the metal leaf molded container is the metal leaf. Vibrate in the molded container.
Due to this vibration, a force perpendicular to the bottom wall of the metal leaf molding container is repeatedly applied to the bottom wall of the metal foil molding container. As a result, the boundary between the bottom wall and the peripheral wall of the metal foil molding container is repeatedly deformed, and as a result, there is a problem that a defect such as a hole is generated in the boundary.

As in Patent Document 1, an attempt has been made to form a rib extending from the bottom wall of the metal leaf molding container to the peripheral wall to improve the strength of the boundary between the bottom wall and the peripheral wall. It has not been possible to consider a shape that suppresses repeated deformation of the boundary due to vibration of the contents, and the strength is still insufficient.

Japanese Unexamined Patent Publication No. 11-29131

Therefore, the problem to be solved by the present invention is to suppress repeated deformation of the boundary between the bottom wall and the peripheral wall due to the vibration of the contents of the metal leaf molding container made by press-molding the metal foil, and improve the strength. It is to suppress the perforation that occurs at the boundary.

In order to solve the above-mentioned problems, the metal leaf forming container according to the invention includes a bottom wall, a peripheral wall rising from the peripheral edge of the bottom wall, and ribs protruding on the bottom wall in a direction perpendicular to the surface of the bottom wall. The tip of the rib in the protruding direction has an arc shape with a radius of 1.2 mm or more and 2.5 mm or less.

When a metal leaf molding container is wrinkled and molded from a metal foil by a press molding method using a mold, when ribs are formed in the container, the ribs are derived from the clearance between the male mold and the female mold. The tip in the protruding direction inevitably becomes an arc shape.
In the conventional metal leaf molding container, the radius of the arc at the tip of the rib exceeds 5 mm, but if the radius of the arc is large and the rib is rounded, the strength of the rib becomes insufficient. It ends up.
In the present invention, since the radius of the arc at the tip of the rib is minimized to 2.5 mm or less, the rib approaches the shape with a sharp tip, and its strength can be improved. On the other hand, if the radius of the arc at the tip of the rib is less than 1.2 mm and the tip is extremely sharp, the tip of the mold for forming the tip of the rib becomes too sharp and the tip of the rib is formed. In the present invention, the radius of the arc at the tip of the rib is set to 1.2 mm or more because the metal leaf may be torn from the portion.

In the metal leaf molding container according to the present invention, the opening angle of the rib along the protruding direction is preferably 135 degrees or more and 150 degrees or less.
This is because if the opening angle of the rib is less than 135 degrees, the tip of the mold for forming the rib becomes too sharp, and the metal leaf may be torn due to the pressing of the tip.
Further, if the opening angle of the rib exceeds 150 degrees, the rib becomes a flat shape widened in the circumferential direction of the peripheral wall and the bottom wall, and the strength of the rib may be insufficient.

In the metal leaf molded container according to the invention, a plurality of the ribs are continuously arranged in parallel in the circumferential direction of the bottom wall, and as a whole, a valley projecting toward the inner surface of the container and a projecting toward the outer surface of the container. It is preferable that the peaks have a wavy shape that is alternately repeated in the circumferential direction of the bottom wall.
By densifying the ribs close to the boundary between the peripheral wall and the bottom wall without gaps, the strength at the boundary can be greatly improved.

In the metal leaf molding container according to the present invention, it is preferable that the height difference between the tip of the rib in the protruding direction and the tip of the peak in the protruding direction is 0.8 mm or more and 2.0 mm or less.
The strength of the rib can be improved by forming the valley and the mountain deeply, but if the height difference between the valley and the mountain is less than 0.8 mm, the valley and the mountain may be too shallow and the strength may be insufficient. This is because if the height difference exceeds 2.0 mm, the metal foil may be excessively stretched during molding and may be torn.

In the metal leaf molding container according to the present invention, it is preferable that the rib extends from the bottom wall to the peripheral wall and projects on the peripheral wall in a direction perpendicular to the surface of the peripheral wall.
By forming a rib straddling the boundary portion between the peripheral wall and the bottom wall, the strength at the boundary portion can be improved.

In the metal leaf molding container according to the present invention, the rib is formed on the peripheral wall from the boundary with the bottom wall to the upper side by 2.5 mm or more at a vertical height, and is formed on the bottom wall from the boundary with the peripheral wall. It is preferably formed up to 2.5 mm or more inward along the surface of the bottom wall.
If it is less than the above range, the distance between both ends of the rib and the boundary between the peripheral wall and the bottom wall is too short, and the total length of the rib is too short, so that the reinforcing effect of the boundary may be insufficient.

In the metal foil molding container according to the invention, the metal foil is preferably an aluminum foil.
This is because molding is easy, material cost is low, and recycling is easy.

It is possible to form a food package from the metal leaf molding container according to the invention and the food stored in the metal leaf molding container.

Since the metal leaf molding container according to the invention is configured as described above, the bottom wall and the peripheral wall are suppressed by suppressing the repeated deformation of the boundary between the bottom wall and the peripheral wall due to the vibration of the contents and improving the strength. It has become possible to suppress the perforations that occur at the boundary due to the repeated deformation of the boundary.

(A) is a perspective view of the metal leaf molding container of the embodiment, and (b) is a vertical sectional view of the metal leaf molding container of the embodiment. (a) is a cross-sectional view of the metal leaf molded container of the embodiment at the point indicated by the arrow in FIG. 1 (b), and (b) and (c) are partially enlarged views of (a). (A) is a schematic diagram showing the manufacturing process of the metal leaf molding container of the embodiment, and (b) is the manufacturing process of the conventional metal leaf molding container with ribs. Schematic diagram of repeated deformation test

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The metal foil molding container 10 of the embodiment shown in FIG. 1A is composed of a bottom wall 11, a peripheral wall 12, a flange 13, a rim winding 14, and a large number of ribs 15, and is composed of an aluminum foil, an iron foil, and the like. It is produced by integrally molding (press molding) a metal foil such as a copper foil using a mold.
When the food package is constructed using the metal leaf molded container 10 of the embodiment, the food is stored in the storage space partitioned by the bottom wall 11 and the peripheral wall 12, and the peripheral wall 12 constituting the opening of the container 10 is stored. The upper edge will be sealed with a film or the like.

Here, the type of metal foil is not particularly limited, but aluminum foil is preferable because it is lightweight, inexpensive, and easy to mold and reuse.
The thickness of the metal foil is also not particularly limited, but is preferably 70 to 100 μm. If it is less than 70 μm, it may be too thin to obtain the required strength when molded into a container, and if it is more than 100 μm, it is too thick and the moldability is lowered, and the material cost is high.

The bottom wall 11 is substantially square, but each side thereof bulges outward and is rounded as a whole. Food will be placed on the bottom wall 11.
In the figure, the bottom wall 11 is flat, but it can be reinforced by forming a large number of uneven portions and ribs by embossing or the like.

The peripheral wall 12 has a lower edge portion connected to the peripheral edge of the bottom wall 11, and rises from the lower edge portion extending toward the upper edge portion constituting the opening of the container 10.
The rising angle of the peripheral wall 12 is different between the upper half and the lower half, and the lower half stands at an angle closer to vertical than the upper half. The boundary between the upper half and the lower half of the peripheral wall 12 is a step portion 12a.
Further, the upper edge portion of the peripheral wall 12 constitutes a substantially square contour similar to that of the bottom wall 11.

The flange 13 has a substantially square ring shape and extends substantially horizontally from the upper edge of the peripheral wall.
Note that the lines attached to the upper half of the middle peripheral wall 12 and the flange 13 in FIG. 1A show wrinkles that naturally occur when the container 10 is press-molded from the metal foil using a mold. This wrinkle may also appear in the lower half of the peripheral wall 12, but is not shown in the figure for convenience of explanation.
The upward edging 14 is connected to the outer edge of the flange 13.

Each rib 15 extends from the edge of the bottom wall 11 to the lower half of the peripheral wall 12, that is, to the lower side of the step portion 12a through the boundary between the bottom wall 11 and the peripheral wall 12. The rib 15 is not provided on the inner side of the edge of the bottom wall 11 and on the upper half of the peripheral wall 12, that is, on the upper side of the step portion 12a.
Each rib 15 projects perpendicularly to the surface of the bottom wall 11 on the bottom wall 11, and projects perpendicularly to the surface of the peripheral wall 12 on the peripheral wall 12.
A large number of ribs 15 are arranged in parallel in a continuous state over the entire circumference of the edge of the bottom wall 11 and the entire circumference of the lower half of the peripheral wall 12.
As a result, the appearance of a large number of ribs 15 as an aggregate is such that the mountain 15a projecting toward the outer surface of the container 10 and the valley 15b projecting toward the inner surface of the container 10 form the circumference of the bottom wall 11 and the peripheral wall 12. It has a wavy shape that repeats alternately in the direction.

Here, the forming range of the rib 15 is not particularly limited, but it is preferable that the rib 15 is formed on the peripheral wall 12 from the boundary with the bottom wall 11 to the upper side by 2.5 mm or more in the vertical height.
If it is less than 2.5 mm, the distance between the end of the rib 15 on the peripheral wall and the boundary between the peripheral wall and the bottom wall is too short, and the length of the rib 15 on the peripheral wall 12 is too short, so that the boundary reinforcing effect is obtained. This is because there is a risk that
Further, on the bottom wall 11, it is preferable that the bottom wall 11 is formed from the boundary with the peripheral wall 12 to the inside by 2.5 mm or more along the surface of the bottom wall 11.
Similarly, if it is less than 2.5 mm, the distance between the end of the rib 15 on the bottom wall and the boundary between the peripheral wall and the bottom wall is too close, and the length of the rib 15 on the bottom wall 11 is too short. This is because the reinforcement effect of the boundary may be insufficient.
It is more preferable that the length of the rib on the bottom wall 11 from the boundary with the peripheral wall 12 is 15 mm or less. If it exceeds 15 mm, the rib formation range on the bottom wall 11 is too wide, which may hinder the storage of food to be placed on the bottom wall 11.

Each rib 15 has a substantially triangular cross section in the direction perpendicular to the extending direction from the bottom wall 11 to the peripheral wall 12, but only the tip of the peak and the tip of the valley of the rib 15 are slightly rounded. It is tinged and has an arc shape.
The radius R of the arc-shaped tip of the rib 15 is adjusted to 1.2 mm ≦ R ≦ 2.5 mm.
This is because if the radius of the tip of the rib exceeds 2.5 mm, the overall shape of the rib becomes rounded and the strength is insufficient. Further, if the radius of the tip of the rib is less than 1.2 mm, the tip of the mold for forming the tip of the rib becomes too sharp, and the metal foil may be torn from the tip of the rib. Is.
On the other hand, in the conventional metal leaf molding container, the radius of the arc-shaped tip of the rib formed from the bottom wall 11 to the peripheral wall 12 exceeds 5 mm, and the overall shape of the rib has a large rounded shape. Therefore, the strength is significantly insufficient.
Such a difference between the radius of the tip of the rib of the metal leaf molding container of the embodiment and the radius of the tip of the rib of the conventional metal foil molding container is derived from the rib forming method described later.

Further, the depth of the rib 15, that is, the height difference h between the peak 15a and the valley 15b is not particularly limited, but is preferably 0.8 mm ≦ h ≦ 2.0 mm.
If the height difference is less than 0.8 mm, the unevenness is too shallow and the strength may be insufficient. If the height difference exceeds 2.0 mm, the metal foil is excessively stretched during molding. This is because there is a risk of tearing.
The method of forming the rib, which will be described later, is also related to the adjustment of the height difference between the peak 15a and the valley 15b in the rib 15.

In the rib 15 having a triangular cross section, the angle (opening angle) θ of the tips of the peaks 15a and valleys 15b is not particularly limited, but it is preferably 135 degrees ≤ θ ≤ 150 degrees.
This is because if the angle is less than 135 degrees, the tip of the mold becomes too sharp and the metal leaf pressed against the tip may be torn.
Further, if the angle exceeds 150 degrees, the height of the rib becomes short, and the strength may be insufficient.
The method of forming the rib, which will be described later, is also related to the adjustment of the angle of the rib 15.

Next, with reference to FIG. 3, the difference between the rib forming method in the metal leaf forming container of the embodiment and the rib forming method in the conventional metal foil forming container will be described.

First, as shown in FIG. 3A, in the metal foil molding container of the embodiment, a mold 20 having deep unevenness is used, and the metal foil is applied only to the tops of the ridges 21a and 22a of the upper mold 21 and the lower mold 22. It is manufactured by bringing the upper mold 21 and the lower mold 22 into close contact with each other in a state where f is in contact with each other.
Even when the upper die 21 and the lower die 22 are close to each other, a relatively large gap is left between the opposite peaks 21a and 22a and the valleys 21b and 22b.
The metal leaf f at the portion of the upper die 21 that abuts on the top of the ridge 21a is sufficiently extended toward the bottom of the valley 22b of the lower die 22 that faces the upper die 21. Similarly, the metal leaf f at the portion of the lower mold 22 that abuts on the top of the ridge 22a is sufficiently extended toward the bottom of the valley 21b of the upper mold 21 that faces the lower mold 22.
This makes it easy to increase the height difference between the peaks and valleys of the rib 15. In addition, it becomes easy to reduce the angle between the tips of the peaks and valleys.
Further, by reducing the radius of the arc at the tip of the peak or valley of the mold, the radius of the tip of the peak or valley of the rib 15 is reduced in the metal leaf f that is strongly pressed in the extended state. It becomes possible to do.

On the other hand, as shown in FIG. 3B, in the conventional metal leaf molding container, the metal leaf f is in contact with almost the entire surface of the upper mold 31 and the lower mold 32 by using the mold 30 having shallow unevenness. , It is manufactured by bringing the upper mold 31 and the lower mold 32 close to each other so that there is almost no gap between them.
With the upper mold 31 and the lower mold 32 close to each other, the peak 31a of the upper mold 31 and the valley 32b of the lower mold 32, and the valley 31b of the upper mold 31 and the peak 32a of the lower mold 32 are extremely close to each other, leaving a so-called clearance. It is in a state of being.
Since the metal leaf f is hardly stretched at the time of forming the rib, it is difficult to increase the height difference between the peak and the valley, and the unevenness of the mold 30 is shallow, and the peaks 31a, 32a and the valleys 31b, 32b are shallow. Since the angle of the tip of the rib tends to be large, it is difficult to reduce the angle of the tip of the rib that depends on these angles.
Further, even if the radius of the arc at the tip of the peak 31a, 32a or the valley 31b, 32b of the mold 30 is reduced, the metal leaf f is weak in a state where it hardly extends to the tip of the peak or valley of the mold 30. The radius of the tip of the ridge or valley of the rib is small enough to reflect the radius of the tip of the ridge or valley of the mold 30 because it is pressed or only faces with a slight gap. Can't be.

Hereinafter, the contents of the present invention will be further clarified by giving examples and comparative examples of the present invention.

The aluminum foil molded containers of Examples and Comparative Examples as shown in Table 1 below were prepared.
In the table, t is the thickness of the aluminum foil (μm), R is the radius (mm) of the arc that constitutes the tip of the rib peak or valley, and θ is the opening angle (degree) of the rib peak or valley. h indicates the height difference between adjacent peaks and valleys, and L indicates the length (mm) of the ribs formed on the bottom wall.
The overall shape and rib formation mode of the aluminum foil molded container of Examples and Comparative Examples are the same as those shown in the embodiment, and the dimensions thereof are substantially the same in Examples and Comparative Examples.
Further, the aluminum foil molded container of the example was manufactured by the method shown in FIG. 3 (a), and the aluminum foil molded container of the comparative example was manufactured by the method shown in FIG. 3 (b). No abnormality was found.

The aluminum foil molded containers of these Examples and Comparative Examples were repeatedly subjected to deformation tests using the apparatus shown in FIG.
The device of FIG. 4 includes a cylinder 41, an arm 42, a pedestal 43 installed so as not to be able to move up and down, and a light source 44 arranged below the pedestal 43.
The aluminum foil molded containers of Examples and Comparative Examples are attached by clamping the bottom wall from above and below by the bottom fixing portion 42a of the arm 42, and the holding plate of the flange fixing portion 43a of the pedestal 43 is applied to the flange from above and below. Attach by fastening with.
In this state, when the cylinder 41 is operated to move the bottom fixing portion 42a of the arm 42 up and down, the bottom wall of the aluminum foil molded container fixed to the arm 42 vibrates in the vertical direction. On the other hand, since the peripheral wall of the aluminum foil molded container is fixed to the pedestal 43 by the flange fixing portion 43a via the flange, a force for deforming is repeatedly applied to the boundary between the peripheral wall and the bottom wall. Become.
In this repeated deformation test, the bottom fixing portion 42a of the arm 42 clamps the bottom wall of the container with a circular surface having a diameter of 40 mm, the amplitude is 10 mm, and the frequency is 1 time / sec.
Further, one vibration started from a flat state of the bottom wall, deformed the bottom wall upward by 10 mm, and returned the bottom wall to the flat state again.
For the aluminum foil molded containers of Examples and Comparative Examples, the number of vibrations of the bottom fixing portion 42a of the arm 42 until a hole was formed at the boundary between the peripheral wall and the bottom wall was measured.
The presence or absence of holes was determined by whether or not the light emitted from the light source 44 arranged below the pedestal 43 passed through the boundary between the peripheral wall and the bottom wall of the aluminum foil molded container.

The results are shown in Table 2 below. From the results in Table 2, it was found that the aluminum foil molded container of the example had a larger number of vibrations of the arm in the repeated deformation test than the aluminum foil molded container of the comparative example. The reason is that the aluminum foil molded container of the example suppresses the deformation of the boundary between the bottom wall and the peripheral wall of the aluminum foil molded container and improves the strength as compared with the aluminum foil molded container of the comparative example. It is presumed that in the aluminum foil molded container of Example 2, the strength of the boundary between the bottom wall and the peripheral wall was dramatically improved, so that the number of vibrations until the hole was formed increased.

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

The mode of forming the rib is not limited to the embodiment as long as it is formed on the bottom wall that contributes to the suppression of drilling. For example, it may be provided only on the bottom wall without being formed on the peripheral wall, or may be provided on the upper half of the peripheral wall. Further, it may be provided intermittently in the circumferential direction of the bottom wall and the peripheral wall.
The overall shape of the metal foil molded container is not limited to the embodiment. For example, the bottom wall may be circular or polygonal.

10 Metal leaf molding container of the embodiment 11 Bottom wall 12 Peripheral wall 12a Step portion 13 Flange 14 Edge winding 15 Rib 15a Mountain 15b Valley 20 Mold for metal leaf molding container of the embodiment 21 Upper mold 21a Mountain 21b Valley 22 Lower mold 22a Mountain 22b Valley 30 Mold for conventional metal leaf molding container 31 Upper mold 31a Mountain 31b Valley 32 Lower mold 32a Mountain 32b Valley 40 Repeated deformation test device 41 Cylinder 42 Arm 42a Bottom fixing part 43 Pedestal 43a Flange fixing part 44 Light source h Height difference between rib peaks and valleys θ Opening angle at the tip of the rib R Radius of the arc at the tip of the rib f Metal leaf

Claims (8)

With the bottom wall
A wrinkled peripheral wall that rises from the periphery of the bottom wall,
It extends from the bottom wall only to the lower half of the lower and upper halves of the peripheral wall, projects vertically on the bottom wall with respect to the surface of the bottom wall, and on the lower half of the peripheral wall of the peripheral wall. With ribs that project perpendicular to the surface ,
The tip of the rib in the protruding direction is a metal leaf molded container having an arc with a radius of 1.2 mm or more and 2.5 mm or less. The metal leaf molding container according to claim 1, wherein the opening angle of the rib along the protruding direction is 135 degrees or more and 150 degrees or less. A plurality of the ribs are continuously arranged in parallel in the circumferential direction of the bottom wall, and as a whole, valleys protruding toward the inner surface of the container and peaks protruding toward the outer surface of the container form the circumference of the bottom wall. The metal leaf molding container according to claim 1 or 2, which has a wavy shape that is repeated alternately in a direction. The metal leaf molding container according to claim 3, wherein the rib has a height difference of 0.8 mm or more and 2.0 mm or less between the tip portion in the protruding direction of the valley and the tip portion in the protruding direction of the mountain. The rib is
The metal leaf molding container according to any one of claims 1 to 4, which is formed on the bottom wall from the boundary with the peripheral wall to the inside by 2.5 mm or more along the surface of the bottom wall. The rib is
It is formed on the peripheral wall from the boundary with the bottom wall to the upper side by 2.5 mm or more at a vertical height.
The metal leaf molding container according to any one of claims 1 to 5, which is formed on the bottom wall from the boundary with the peripheral wall to the inside by 2.5 mm or more along the surface of the bottom wall. The metal foil molded container according to any one of claims 1 to 6, which is made of aluminum foil. The metal leaf molded container according to any one of claims 1 to 7.
A food package comprising the food stored in the metal leaf molded container.

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