JPH0422784B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite beverage can that is completely impermeable to the body and has good sealing properties for beverages, particularly fruit beverages that have been sterilized by high temperature heating.

Conventionally, a surface paper made of aluminum foil paper with a synthetic resin layer is pasted on one or both sides of a cylinder made by polymerizing and bonding multiple strips in a spiral manner. A cylindrical container with a lid tightly secured is known.

This container has a simple moisture-proofing effect, so even if solid foods such as snack foods are directly filled at room temperature,
It is currently widely used because it does not become damp and does not deteriorate the quality of the solids it is filled with.

However, it is difficult to guarantee the quality of tea leaves, powdered coffee, etc., which are extremely sensitive to aroma loss, discoloration, moisture, etc., by simply filling and sealing them, so a special device is used to remove the air from the container and reduce the pressure. However, there are still cases of cracks, tears, and pinholes in the aluminum foil due to bending at the edge seal of the surface paper attached to one or both sides of the fuselage. Although it is often judged that there is no problem in appearance due to imperfections in the sealing part caused by wrinkles, the inside of the container may deteriorate after a few days due to the lack of gas barrier properties, airtightness, and sealing properties. Glass bottles and metal cans are still used for direct packing, as there are functional problems in which the gas is no longer under reduced pressure and the replaced gas escapes.

Furthermore, when a beverage that has been subjected to high-temperature heat sterilization at 90°C or higher, which is the object of storage in the present invention, is filled into the above-mentioned known container under almost the same conditions and sealed, when the temperature of the filled beverage drops, the pressure inside the container becomes reduced. become.
The stress of this reduced pressure causes enlargement of defective adhesion and delamination on the inner wall of the container body, causing inward lifting (protrusion). Moreover, peeling or lifting of the seal portion occurs. These phenomena have a high probability of occurring in the surface paper layer, and damage to the aluminum foil, which is used primarily for gas barrier properties, airtightness, etc., is noticeable.

In addition, since vibrations and shocks generated during handling and transportation after filling and sealing are constantly applied, under the stress of reduced pressure inside the container, peeling may expand, seal defects may increase, aluminum foil may break, pinholes, cracks, etc. The damage spreads, and the innermost resin film layer locally stretches, resulting in a lack of gas barrier properties, airtightness, and moisture resistance, and the permeation of beverage into the body, resulting in deformation and damage to the container. .

In addition, in order to prevent the cut surface of the edge of the surface paper affixed to the inner surface of the container body from being exposed, we have developed a technology in which one edge is bent and the other edge is overlapped and sealed. is known, but when folding the edge of the surface paper, cracks in the aluminum foil at the folded point,
Pinholes, wrinkles, and local stretching and tearing of the synthetic resin layer occur.

Furthermore, during sealing, bending and polymerization seals are prone to damage near the seal due to misalignment and damage of the bent edges, as well as cracks, pinholes, and tears due to multiple bends in the aluminum foil, resulting in poor gas barrier properties. , the sealing and moisture-proofing effects are completely lost.

In addition, if the metal lid is only attached to the upper and lower opening edges of the body of the known container through a viscous compound locally applied, the filled beverage will penetrate into the opening edge of the body. Penetration causes the edges to swell, causing the tightened parts to loosen or come off due to vibrations, shocks, etc., deterioration in the strength of the edges, and deformation of the body.
Airtightness, gas barrier properties, and sealing properties are completely ineffective, leading to leakage and spillage of the filled beverage.

As described above, conventionally known containers lack practicality in terms of functionality and strength as containers.

An object of the present invention is to provide a composite beverage can that eliminates the above-mentioned drawbacks of the conventional beverage can. It consists of a cylindrical container body 2 bonded and formed, and a metal lid 3 integrated with double fastening at its open end, (B) The composite inner surface constituent material 4 is made of lining paper 41, thermoplastic A resin film 42, an aluminum foil 43, and a thermoplastic resin film 44 are sequentially polymerized on the inner surface to form an integral belt-like material, and (C) one edge 45 of the belt-like material is covered with a lining paper 41.
While bending to the side, the thermoplastic resin film 44 of the folded part 46 formed by bonding the facing lining papers 41 with adhesive 47 is polymerized and bonded to the thermoplastic resin film 44 of the other end edge 48. (D) The paperboard material 5 is wound and adhered to the upper surface of the composite inner surface component 4, and (E) The composite surface component 6 includes a backing paper 61 and a thermoplastic resin. The winding 62 and the aluminum foil 63 are formed of an integral strip which is sequentially overlapped on the surface side, and one edge of the strip is overlapped with the other edge and spirally applied to the upper surface of the paperboard material 5. (F) At least one opening of the cylindrical container body 2 is covered with a metal lid 3 via a synthetic resin 23 at its tip. This is a composite beverage can characterized by being integrated by double seaming.

In particular, the present invention provides the composite inner surface component 4 of the requirement (C).
By adopting a special configuration for the bending portion 46 of the aluminum foil 63, the weak point of deterioration of airtightness due to cracking or peeling caused by the bending process of the aluminum foil 63 is eliminated.

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a composite beverage can 1 according to the present invention, which includes a body 2 formed into a cylindrical shape by winding and gluing a plurality of strips in a spiral shape, and an upper and lower opening of the body 2. It is composed of a metal lid body 3 that closes the end.

FIG. 2 shows a partial cross section of the fuselage 2, and its main structure is as follows.

That is, the body 2 is composed of a composite inner surface material 4 made of laminated composite materials from the inside, a paperboard material 5, and a composite surface material 6 made of laminated composite materials.

First, the composite inner surface material 4 constituting the inner surface layer of the body 2 is made of a thermoplastic resin film 42 such as polyethylene with a thickness of about 15μ and an aluminum foil 43 with a thickness of about 9μ on one side of a lining paper 41 such as thin kraft paper. , and a thermoplastic resin film 44 of polyethylene or the like having a thickness of approximately 60 μm are sequentially polymerized and integrated.

Band-shaped composite inner surface constituent material 4 configured in this way
To join the edges, one edge 45 is bent so that the surface of the lining paper 41 overlaps with the folded portion 46.
The backing papers 41 which are bent at the bending part 46 and facing each other are fixed with an adhesive 47 and laminated to form one backing paper 41.

The purpose of processing this lining paper 41 with adhesive 47 is to integrate the folded part 46, and even if a crack occurs in the aluminum foil 43 at this folded part 46, it will not be able to pass through this crack. This is to prevent air etc. from entering the composite can 1.

Further, the other end edge portion 48 is integrally bonded by polymerization adhesion (fusion bonding) 49 so as to be located on the lower surface of the bent portion 46, and the composite inner surface structure material having the edge portions bonded in this manner is formed. 4 is spirally wound to form a cylindrical shape.

Further, the paperboard material 5 is preferably a fiber waste material that is relatively thick, strong, and easy to process, such as kraft paper or cardboard. The paperboard material 5 is wrapped and bonded to the paper backing side of the composite inner surface component 4.

The composite surface material 6 forming the surface layer of the body 2 includes a thermoplastic resin film 62 such as polyethylene with a thickness of about 15μ and an aluminum foil 63 with a thickness of about 7μ on one side of a backing paper 61 such as thin kraft paper. It is a composite material made by sequentially polymerizing and integrating the above-mentioned paperboard material 5, and is pasted onto the upper surface of the paperboard material 5 in a spiral shape while polymerizing its edges. In this case, one end edge 6 exposed to the outside
It is preferable that synthetic resin 66 be impregnated or coated on the cut surface 65 of No. 4 and its vicinity.

Further, the composite surface constituent material 6 can be appropriately printed for the purpose of displaying products, displaying effects, and the like.

In this way, the composite can 1 for beverages according to the present invention is
Since the body 2 is configured as above,
Even if the beverage is filled with a beverage that has been sterilized by heating at a temperature of 90°C or higher, there will be pinholes caused by dents, scratches, bends, wrinkles, etc. that occur during handling or during the molding of the body 2.
Since the composite inner surface material 4 is free from cracks and damage, gas barrier properties, airtightness, etc. are perfect.

Furthermore, since the width of the bent portion 46 of the bonded (fused) portion 49 is uniform, there is no occurrence of multiple wrinkles or cracks due to misalignment or scratches.
There are no non-adhesive parts on the inside, resulting in stable and uniform adhesion (fusion), resulting in strong retention. Therefore, permeation and leakage of the beverage can be completely prevented, and strength deterioration of the composite can 1 can also be prevented. Furthermore, since the composite surface constituent material 6 can prevent moisture and water from entering and penetrating from the outside, there is no deterioration in the strength of the body 2.

When carrying out the present invention, a metal lid 3 is attached to one opening end of the body 2 configured as described above by double-sealing to close one opening, and the lid body 3 is heated at a temperature higher than 90°C. After filling the beverage which has been sterilized by high temperature heating under almost the same conditions, a metal lid 3 is attached to the other open end by double-sealing to seal it. As shown in the figure, a flange 21 projecting outward is provided at the open end of the body 2, and a synthetic resin 23 is applied to the tip 22 of the flange 21 and its vicinity before the double seaming process. It is necessary as a process.

By performing this pretreatment, the following effects can be obtained.

That is, by providing the flange 21, double seaming can be performed without difficulty, and by impregnating or coating the tip 22 of the flange 21 with the synthetic resin 23, when filling the beverage, Beverage can be prevented from entering the body 2, and strength deterioration of the body 2 can be prevented.

Furthermore, as shown in FIG.
A viscous polymer 3 such as polyvinyl acetate is provided at the bottom 33 of the groove 32 and in the vicinity thereof.
Give 4.

Further, a coating layer 31 made of an arbitrary material is provided on one or both of the upper surface and the lower surface of the metal plate of the metal lid body 3 in order to obtain effects such as rust prevention and corrosion resistance.

The effects obtained by double seaming the metal lid body 3 configured in this way are as follows.

That is, as shown in FIG. 4, the flange 21 at the open end of the body 2 is covered with the groove 32 at the periphery of the metal lid 3 by overlapping and tightly double-sealing. Can be tightly closed.

Furthermore, by interposing the viscous polymer 34, it is possible to double-seal tightly, and there will be no leakage of the beverage. Furthermore, by providing the coating layer 31, it is possible to prevent rust and corrosion of the metal lid body 3, as well as to prevent oxidative corrosion caused by contact between the beverage and metal, and to improve the taste, color, aroma, etc. of the beverage due to chemical reactions. This has the effect of preventing changes in quality.

The composite can for beverages of the present invention is constructed as described above, and is particularly suitable as a composite can for fruit beverages, and has excellent gas barrier properties, sealing properties, airtightness, waterproof and moisture-proof properties, rust prevention, corrosion prevention properties, etc. Therefore, it is possible to maintain the beverage in a completely sealed state for a long period of time and guarantee it for a long period of time. or,
The edges of the composite inner surface material forming the inner surface layer of the fuselage are joined together by strong adhesion (fusion) between the bent portion of one edge and the other edge. Since the width is made uniform and the backing paper 41 laminated on the inner surface of the folded portion 46 is bonded to each other with the adhesive 47, the stress generated by constant decompression acts on the inner wall of the body 2. Even if the composite inner surface constituent material 4 is peeled off, especially the bent portion 46, swelling deformation and peeling or damage of the adhesive portion 49 can be prevented, and the contents can be prevented from deteriorating in quality.

In addition, by providing an outwardly projecting flange at the open end of the body and applying synthetic resin to the tip, the metal lid can be double-sealed smoothly and the beverage When filling the container, it is possible to prevent the beverage from entering or penetrating the container. Therefore, it is possible to prevent the edges of the polymer of the composite inner surface material, the composite surface material, and the paperboard material forming the fuselage from curling up, completely preventing deterioration in the strength of the fuselage, and making it possible to completely prevent deterioration of the strength of the fuselage under reduced pressure conditions. It is possible to obtain a strong composite beverage can that does not deform even when

[Comparative example]

In order to confirm the adhesion effect of the adhesive 47 on the bent portion 46 formed on the composite inner surface component 4 of the composite beverage can 1 of the present invention, a composite can 1 was created in which the adhesive 47 was omitted. Composite inner surface component 4 in the bent portion 46 when the inside thereof is kept in vacuum
We observed the state of change.

FIG. 6 is an explanatory diagram of this state, and when the lining paper 41 is not adhered at the folded portion 46, when the pressure inside the body portion 2 is reduced, this folded portion 46
The air in the space 46a formed near the
Alternatively, the air a that has entered from the paperboard material 5 via the space 46a enters into the space 50 formed by peeling off the bent portion 46.

On the other hand, since the bent portion 46 is strongly bent, a crack 51 often occurs in the aluminum foil 43 constituting the composite inner surface component 4.
It was confirmed that the air a inside the can entered the inside of the composite can 1.

In addition, the thermoplastic resin films 44 forming the innermost layer of the body portion 2 are bonded by polymer winding 49 at the overlapping surfaces.
However, as described above, when the bent portion 46 deforms as shown in FIG. 6, a peeled portion 49a may be formed at the adhesive 49, and the airtightness may be rapidly reduced. confirmed.

[Brief explanation of drawings]

FIG. 1 is an overall view of a composite beverage can according to the present invention, FIG. 2 is a sectional view taken along the line A-A in FIG. 1, FIG. 3 is a vertical sectional side view of the open end of the body, and FIG. , FIG. 5 is a longitudinal sectional side view of the metal lid, and FIG. 6 is an explanatory sectional view of a comparative example showing the same portion as FIG. 2. 1... Composite beverage can, 2... Body, 3... Metal lid, 4... Composite inner surface material, 5... Paperboard material,
6... Composite surface constituent material, 21... Flange, 23
... Synthetic resin, 41,61 ... Lining paper, 42,
44,62...Thermoplastic resin film, 43,63...
Aluminum foil, 46...bent part.

Claims (1)

[Claims] 1. A cylindrical container body 2 formed by sequentially adhering a composite inner surface material 4, a paperboard material 5, and a composite surface material 6.
and a metal lid body 3 integrated with the opening end by double tightening, and the composite inner surface component 4 includes a lining paper 41, a thermoplastic resin film 42, an aluminum foil 43, and a thermoplastic resin film 44. It is formed by an integral strip that is sequentially overlapped on the inner surface side, and one edge 45 of the strip is bent toward the lining paper 41 side, and the facing lining papers 41 are bonded together with an adhesive 47. The thermoplastic resin film 44 of the folded bent portion 46 is polymerized and bonded 49 to the thermoplastic resin film 44 of the other edge 48, and the paperboard material 5 is wound and bonded to the upper surface of the composite inner surface component 4. In addition, the composite inner surface component 6 is formed of an integral band-like material in which a lining paper 61, a thermoplastic resin wrap 62, and an aluminum foil 63 are sequentially superposed on the surface side, and one end of the band-like material The cylindrical container body 2 is constructed by wrapping the edge portion of the cylindrical container body 2 in a spiral shape while overlapping the other edge portion and adhering it to the upper surface of the paperboard material 5. is attached to the metal lid body 3 through the synthetic resin 23.
A composite beverage can characterized by being integrated with double seams.