JPH11130039A - Container having wrinkled side-face suitable for heat seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a container having wrinkled side-faces which has a flat, wrinkle-free flange and high buckling strength which causes no troubles in heat sealing on an automatic packaging line. SOLUTION: In the container having wrinkled side-faces having a flange 1 and a tapered part 3, which is made of a material comprising an aluminum foil-synthetic resin composite material, a straightly formed part 2 for absorbing self-generated wrinkles is formed between the flange 1 and the tapered part 3 having self-generated wrinkles. The aluminum foil-synthetic resin composite material is obtained by coating or film-laminating at least one side of aluminum foil with heat seal lacquer or synthetic resin. And the inside of the wrinkled-side- having container is a non-aluminum foil face coated or laminated with the aluminum foil-synthetic resin composite material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simple packaging container used for desserts, cooked foods, etc.
More particularly, it relates to a side wrinkled container having a smooth wrinkle-free flange suitable for heat sealing.

[0002]

2. Description of the Related Art Heat-cooked foods such as desserts and retort foods such as fried rice, curry, stew and gratin,
Various containers made of metal foil, plastic, paper, etc. are commercially available as containers for simple packaging of pharmaceuticals, industrial materials, etc. Among them, when metal foil is used, aluminum foil or aluminum alloy foil (both are referred to as foils such as aluminum) .) Is most widely used without wrinkles made of an aluminum foil-synthetic resin composite material laminated with a heat seal lacquer or a plastic film. Containers such as udon and ramen are generally 100 μm or less (usually 60 to 80 μm) as containers that can be used for cooking with open flames.
2. Description of the Related Art A wrinkled container having excellent shape retention even though it is thin and deep drawn by a press using a foil of aluminum or the like having a thickness of about the same is widely used.

[0003] When filling and sealing the contents of these simple packaging containers, a dedicated and automated filling and sealing machine is used, so that one empty container stacked on the belt line is automatically placed on the belt line. A side face is provided with a taper for taking out the pieces one by one. In addition, the taken-out container is filled with the contents, covered with a lid material and automatically heat-sealed with a heat sealer. In this case, in a conventional container with side wrinkles, as shown in FIG. Wrinkles are formed, and this distortion affects the flange part, wrinkles enter the flange part, and even after heat sealing, there were places that could not be sealed and sealing could not be performed, or even if the flange did not wrinkle In some cases, the distortion affects the flange portion, and automatic heat sealing by the heat sealer cannot be performed well. On the other hand, a container without side wrinkles does not cause such a problem, but it is necessary to increase the thickness of the material in order to enhance the shape retention (rigidity) of the container.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a deep drawn deep-wrinkled container using an aluminum foil-synthetic resin composite material, which container has a flat wrinkle-free flange portion. Another object of the present invention is to develop a container having a large buckling strength and a side wrinkle which does not cause any trouble in heat sealing in an automatic packaging line and a mold suitable for molding the container.

[0005]

SUMMARY OF THE INVENTION The present invention relates to (1) a container having a side surface wrinkle having a flange portion and a tapered portion using a material made of an aluminum foil-synthetic resin composite material. A container having a side wrinkle suitable for heat sealing, wherein a straight formed portion for absorbing spontaneous wrinkles is provided between the tapered formed portion, and (2) a straight formed portion provided between the flange portion and the tapered formed portion. A container having side wrinkles suitable for heat sealing according to the above (1), wherein the width of the portion is 1 to 10 mm;
(3) The aluminum foil-synthetic resin composite material is obtained by coating a heat-seal lacquer or a synthetic resin on at least one surface of the aluminum foil or laminating a film, and the inner surface of the container having side wrinkles is formed of the aluminum foil. The container with side wrinkles according to the above (1) or (2), which is a non-aluminum foil surface coated or laminated with a synthetic resin composite material;

(4) A method for producing a container with side wrinkles suitable for heat sealing, characterized by using a molding die combining a die and a punch composed of a tapered punch portion and a straight punch portion and a wrinkle presser, (5) Dies The heat as described in (4) above, wherein a mold having a sufficient width of clearance between the inner surface and the tapered punch of the wrinkle retainer is used to generate naturally-occurring wrinkles in which a container having side wrinkles has the required strength. Manufacturing method for containers with side wrinkles suitable for sealing,

(6) A molding die in which a punch comprising a die, a tapered punch portion and a straight punch portion and a wrinkle press are combined, and which has a sufficient clearance between the die and the punch of the tapered molded portion to generate wrinkles. A mold for a container with side wrinkles suitable for heat sealing, and (7) the height of the straight punch portion is 1 to 10
The above object has been achieved by developing a container mold having a side face wrinkle described in the above (6), wherein the taper of the tapered punch portion is 5 to 15 ° in mm.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The aluminum foil of the aluminum foil-synthetic resin composite used in the wrinkled container of the present invention varies depending on the purpose of use, the size of the container and the like, but generally has a thickness of 30 to 200 μm, preferably 50 μm. ~ 150
μm is appropriate. If the thickness is less than 30 μm, except for a small one such as a mini cup, not only molding becomes difficult, but also the rigidity of the container decreases, and it becomes difficult to maintain the shape when the contents are put. When it is thicker than 200 μm, moldability
Although there is no problem such as shape maintenance, there is no particular advantage, which leads to an increase in cost, which is not preferable. The aluminum foil is always coated or laminated with a synthetic resin such as a heat seal lacquer or a plastic film on one surface, and this surface is the inner surface of the container. In the case of application, many are thin, but when laminating a film,
It is preferable that the thickness is smaller than or equal to the thickness of the aluminum foil. When laminating films on both sides of the aluminum foil, it is preferable that the total thickness of the films on both sides is equal to or smaller than the thickness of the aluminum foil because of good workability. This synthetic resin has no toxicity and does not decompose when cooked for heating cooking [thermosetting resin for heat seal lacquer, polyethylene (LDPE, LLDP) for plastic
E, HDPE) polypropylene (CPP), ethylene-
Vinyl acetate copolymer (EVA) or hot melt. The type is not particularly limited as long as the heat sealing property with the synthetic resin surface of the lid material is good.

The present invention will be described below with reference to the drawings. The purpose of the present invention is to explain the contents of the present invention, and is not limited to those described in the drawings. FIG. 1 or FIG. 2 is shown as one specific shape of the present invention. The container of the present invention (a well-known lid can be used as it is, so description is omitted). The container includes a flange portion 1, a straight molded portion 2 which is not included in a conventional container having side wrinkles, and a tapered molded portion 3. The tapered portion 3 is formed of naturally occurring wrinkles generated at the time of molding, and the proportion of the occupied portion is not constant depending on the size of the container, but is formed so as to occupy a portion of approximately 70% or more of the height of the entire container. Is preferred.

If the height of the straight molded portion 2 only serves as a wrinkle absorbing zone, it is sufficient to simply provide this portion, and the height does not matter much. On the other hand, the tapered portion is preferably provided with a taper of 5 ° or more, preferably 6 ° or more with respect to the recommendation when considering the stacking property of the automatic packaging machine. If the angle of the taper is large, the container becomes wide and the internal volume becomes small. If the height of the straight molded portion is large, the buckling strength of the container is reduced. Therefore, it is preferable to reduce the proportion occupied by this portion within a range in which the naturally generated wrinkles of the tapered molded portion do not affect the flange portion. The length of the straight molded portion has a trade-off with the taper angle, but usually 1 to 10 mm is used.

In the container with side wrinkles of the present invention, wrinkles must be avoided in the flange portion and the straight molded portion, but it is necessary to avoid the occurrence of naturally occurring wrinkles in the tapered molded portion which occupies most of the molded product. Since there is no mold, it is easy to make a mold. As shown in FIGS. 3 and 4, the mold includes a die, a tapered punch portion, a straight punch portion, and a wrinkle retainer. In this case, a clearance (2 to 10 times, preferably 3 to 8 times the thickness of the material) is sufficient between the die and the tapered punch portion to form a naturally occurring wrinkle. It is only necessary to leave an interval with the die, and it is possible to create a naturally occurring wrinkle that secures strength. This is because there is no need to make a precise mold so that the tapered portion does not have wrinkles as in the case of a ribbed container, so that the mold making cost is greatly reduced.

Referring to FIGS. 3 and 4, a description will be given of the structure of a mold of a container with side wrinkles and a method of manufacturing the container with side wrinkles. As shown in FIG.
The synthetic resin composite material C is restrained between the wrinkle presser B and the die A. At this time, the top of the straight punch b2 is at least at a position equal to or lower than the upper surface of the wrinkle holder B, and it is preferable that the molding material is not deformed when the aluminum foil-synthetic resin composite C is engaged. Subsequently, the tapered punch b1 and the straight punch b2 advance while squeezing the molding material C into the die A, and stop at a predetermined height to form a molding container. At this time, wrinkle presser B and die A
A wrinkle pressing force is applied so that the molding material C does not undulate during the period and does not break during molding. The naturally occurring wrinkle of the container generated between the tapered punch part b1 and the die A is the die A
Taper punch side corner and straight punch b2
And has no effect up to the flange portion, forming a flat and undistorted flange portion 1.
As a result, a container with side wrinkles that not only has good stacking properties but also can completely perform heat sealing without errors even in an automatic packaging machine.

[0013]

EXAMPLE As the material of the container body, outer coating (3 microns) / Al (120) (aluminum foil 120 microns) / heat seal lacquer (3 microns) [total thickness: 1]
26 microns], as the material of the lid material, the outer surface coating / Al (7
0) / Aluminum foil-synthetic resin composite material having the structure of heat seal lacquer was used. (Example 1) A mold having the above-mentioned container body material provided with a clearance of 6 mm in height of the straight punch and 0.66 mm (5.2 times the total thickness of the container body) between the inner surface of the die and the straight punch. 1 [flange width 9.5 mm, inner diameter 66 mm in the upper part of the container, inner diameter 64 mm in the lower end of the straight molded part, height 6 mm in the straight molded part, taper angle 8 in the tapered molded part (naturally occurring wrinkle).
°, height of the entire container 22 mm] (hereinafter referred to as shape 1) to form a container body. The container body was stacked in an automatic packaging machine, filled with fried rice as a content, and continuously packaged with the lid material. The packaging was completely heat-sealed without any trouble, and the packaging was successful without any wrinkles on the flange. Table 1 shows the results.

Comparative Example 1 The shape shown in FIG. 5 [the shape of a conventional container with side wrinkles, without a straight molded portion. The height 22 mm, the upper inner diameter 66 mmφ, and the angle of the tapered portion 8 °] (hereinafter referred to as “shape 2”) are set to the clearance 0.66 mm between the inner surface of the die and the tapered punch (5.2 times the total thickness of the container body). It was molded using a mold. Wrinkles were generated on the flange portion, and 12 out of 500 packagings with an automatic packaging machine were leaky. Table 1 shows the results
Shown in (Comparative Examples 2-3) Example 1 and Comparative Example 1 except that a clearance of 0.19 mm (1.5 times the total thickness of the container body) between the inner surface of the die and the tapered punch portion was used as a 1.5 mm mold. Went as it was. In this case, no wrinkles were generated in the molded container, but the buckling strength was low and it could not be said that the molded container was sufficient. Table 1 shows the results.

(Measurement Method) 1) Sealability: Puncture pressure was measured. The measuring method was such that the injection needle was pierced into the lid, the air was injected, and the internal pressure at the time of rupture was measured. 2) Buckling strength: The container was placed downward between two rigid, flat, parallel compression plates, and the upper plate was pressed against the bottom of the container, compressed, and the compression pressure during buckling was measured.

[0016]

[Table 1] * 1: Sealing property: OK No leak occurred. : NG leak occurred. * 2: Buckling strength: 高 い Higher than Comparative Example 2. (× 1.2 or more): Δ Comparative Example 2 (conventional container with side wrinkles): × Lower than Comparative Example 2. (× 0.9 or less)

In the container with side wrinkles according to the present invention, by providing a straight molded portion below the flange portion, the effect of naturally occurring wrinkles of the tapered molded portion is absorbed in this portion, and the flange portion is flat and distortion occurs. It is a difficult shape. As a result, stacking properties in automatic packaging machines,
There is no problem in heat sealability and the like, and there is almost no occurrence of distortion of the container which occurs when stock is required for a long time until use, and the buckling strength is stable. Also, if the tapered punch portion is provided with a sufficient clearance, the accuracy of the finished surface is not a problem, so that the die can be manufactured at a very low cost as compared with a die for a container with ribs.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a container with side wrinkles according to the present invention.

FIG. 2 is a perspective view of the container body with side wrinkles of the present invention.

FIG. 3 is a sectional view of a mold for producing the container of the present invention.
(Before molding starts)

FIG. 4 is a sectional view of a mold for manufacturing the container of the present invention.
(At the end of molding)

FIG. 5 is a cross-sectional view of a conventional container with side wrinkles.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flange 2 Straight molded part 3 Tapered molded part A Die B Wrinkle holder b1 Tapered punch part b2 Straight punch part C Aluminum foil-synthetic resin composite material

Claims (7)

[Claims] In a container having a side surface wrinkle having a flange portion and a tapered portion using a material made of an aluminum foil-synthetic resin composite material, naturally occurring wrinkles are generated between the flange portion and a tapered portion having a naturally occurring wrinkle. A container with side wrinkles suitable for heat sealing, characterized by having a straight molded portion for absorbing. 2. The container with side wrinkles suitable for heat sealing according to claim 1, wherein the width of the straight molded portion provided between the flange portion and the tapered molded portion is 1 to 10 mm. 3. The aluminum foil-synthetic resin composite material is obtained by coating a heat-seal lacquer or a synthetic resin on at least one surface of an aluminum foil or laminating a film, and the inner surface of the container having side wrinkles is formed of 3. The container with side wrinkles according to claim 1, which is a non-aluminum foil surface coated or laminated with an aluminum foil-synthetic resin composite material. 4. A method for manufacturing a container with side wrinkles suitable for heat sealing, characterized by using a molding die in which a die, a punch comprising a tapered punch portion and a straight punch portion and a wrinkle press are combined. 5. A mold having a clearance between the inner surface of the die and the tapered punch of the wrinkle holder having a clearance large enough to generate naturally-occurring wrinkles for obtaining the strength required for the container having side wrinkles. Item 4. A method for producing a container with side wrinkles suitable for heat sealing according to Item 4. 6. A molding die combining a die, a punch comprising a tapered punch portion and a straight punch portion and a wrinkle presser, and having a sufficient clearance between the die of the tapered molded portion and the tapered punch portion to generate wrinkles. A mold for containers with side wrinkles suitable for heat sealing. 7. The height of the straight punch portion is 1 to 10 m.
7. The mold for a container with heat seal side wrinkles according to claim 6, wherein m and the taper of the tapered punch portion are 5 to 15 [deg.].