JPH08324587A - Easily unsealable packaging bag - Google Patents

Abstract

PURPOSE: To provide a packaging bag having aluminum foil as an intermediate layer which can be unsealed by tearing in a certain direction and in a straight line simply by hand and appears nice when unsealed. CONSTITUTION: A sealable packaging bag is formed of a packaging material consisting of a laminate of an aluminum foil 1 as an intermediate layer, a base film 2 on one side thereof, and a thermally adhesive film 4 on the other side, and by using the thermally adhesive film 4 for the inner side of the packaging bag and by effecting the thermal adhesion along the perimetric adges that need it. This packaging bag is made capable of being unsealed easily by preliminarily providing fine holes 5 in the base film 2 at least along a preliminarily set part for the perimetric thermal adhesion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetically sealed package having an aluminum foil as an intermediate layer, which has an excellent appearance and can be opened by tearing straightly in a certain direction by hand regardless of the tearing position of the packaging bag. Regarding the bag.

[0002]

2. Description of the Related Art A bag in which a plastic film having a heat-fusible layer on its inner surface is opposed and its peripheral portion is heat-sealed is a hermetically sealed package for various powders and liquids including foods, pharmaceuticals, etc. Widely used as a bag. The opening of the hermetically sealed bag is performed by manually tearing the V notch or the I notch provided in advance on the peripheral edge portion which is heat-sealed.

However, such V notches or I
Not only is it difficult to find the position of the notch in the packaging bag provided with the notch opening, but it may not be possible to open the notch at the desired position with a single notch such as the I-notch, or it may not be possible to cut straightly. In the case of the V notch, there was a case where biting occurred due to film breakage at the time of sealing, and the cut end after cutting was an acute angle, which might damage other packaging bags.

For this reason, various measures have been taken so that cutting can be performed from any position on the peripheral portion. For example, Tokiko Sho 6
Japanese Unexamined Patent Publication No. 1-39228 discloses a method of pressing or rubbing an abrasive on the film surface or the edge of the film to form a scratch, and molding a sealed bag using this film. -45262 discloses a method of forming a large number of U-shaped or cross-shaped tear grooves over the entire one side edge portion of a sealed bag, and further, Japanese Patent Laid-Open No. 3-27930 discloses a bag edge line. A method is disclosed in which, after forming a large number of penetrating scars at locations along the line, heat fusion is performed along the edge line of the bag along which the scar forming portions extend.

However, according to these methods, when the packaging bag is opened, there are cases in which straight tearability cannot be obtained due to the tearing. That is, Japanese Patent Publication No. 61-392
No. 28 is a method in which an abrasive is pressed or scratched at the end to form a scratch, but in this method, the tearing direction is greatly affected by the directionality of the film and is not constant, and the tear is not straight. There are drawbacks. In addition, JP-A-6
In 4-45262, over the entire side edge of the sealed bag,
This is a method of forming a large number of U-shaped or cruciform laceration grooves. In this method, the tearing direction is more constant than in JP-B-61-39228 and JP-A-64-45262. Therefore, there is a drawback that straight tearability cannot be obtained. In this way, the tearing direction is not constant and is inclined, so that the contents cannot be taken out accurately, and in the case of a liquid contents, there is a problem of contamination such as overflow. Furthermore, Japanese Examined Japanese Patent Publication 61-39228
The shape of the No. has a drawback that the film is easily broken due to the tension applied to the film during slitting, which lowers the productivity.

[0006] For the purpose of solving these drawbacks, an easily openable sealed bag is known in which a penetrating scratch is provided on the seal portion of the bag.
That is, in a plastic sealed bag having at least a base material layer and an adhesive layer and having a seal portion, the base material has a penetrating scar that penetrates through the sealing portion, and the penetrating scar has a part or the whole thereof. An easily openable sealed bag is known which is covered with an adhesive layer (JP-A-62-52065). As a method of manufacturing an easily-openable sealed bag having such a scar, the publication discloses a method of previously fusion-sealing a material having a penetrating scar. However, when this method was applied to a packaging bag formed of a laminated film having an aluminum foil, the aluminum foil was cracked, resulting in poor appearance. Further, after forming the packaging bag, it is conceivable to provide a scratch on the peripheral seal portion, but in this case as well, there was a defect such as cracking in the aluminum foil portion. Further, it was found that moisture penetrates through the cracks from the outside and changes the contents.

[0007]

Therefore, the inventor of the present invention
As a result of various studies to improve such a defect, when a packaging bag is formed using a laminated sheet having an aluminum foil as an intermediate layer, the aluminum foil layer can be used as a base film layer without any scratches. It was found that the object can be sufficiently achieved by providing fine holes, and the present invention has been completed. The object of the present invention is to preliminarily use an aluminum foil in a packaging bag formed using a laminated sheet having an aluminum foil as an intermediate layer. An object of the present invention is to provide an easy-open packaging bag that can be easily opened in a certain direction by tearing a hand without providing any scratch on the layer.

[0008]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a packaging material in which an aluminum foil is used as an intermediate layer, a base film is laminated on one surface of the aluminum foil, and a heat-adhesive film is laminated on the other surface of the aluminum foil. In a hermetically sealed packaging bag formed by heat-bonding the necessary peripheral edge portion so as to be a heat-adhesive film, at least the peripheral portion of the base material film at the portion to be heat-bonded is provided with fine holes in advance. It is an easy-open packaging bag.

That is, the easy-open packaging bag according to the present invention is an easy-open packaging bag in which micropores are provided in the base film layer and no scratches are provided in the intermediate aluminum foil. The foil can be easily opened in a certain direction by tearing the hand without providing any scratches.

In the present invention, the laminated film used as the packaging material uses an aluminum foil as an intermediate layer to secure the moisture-proof property of the packaging bag, and one surface thereof has a thickness of 10 to 40 μm. A film with relatively high mechanical strength, such as an axially stretched polyester film, a stretched nylon film, or a biaxially stretched polypropylene film, is used as a base film to laminate an isocyanate adhesive or molten polyethylene as an adhesive, while the other side of the aluminum foil is laminated. As the heat-adhesive film, a low-density polyethylene, a heat-adhesive resin such as polypropylene is extruded into a film and directly laminated, or these films formed in advance are laminated using an appropriate adhesive. is there. The thickness of the aluminum foil used is about 4 to 20 μm,
The thickness of the heat adhesive film is generally about 15 to 60 μm. In the present invention, fine holes are provided in the base film layer, but in this case, not only the film on the surface but also fine holes may be provided from the surface film to the adhesive layer. The size of the fine pores is 0.1 to 0.
It may be about 5 mm.

The heat-adhesive film of the packaging material made of this laminated film is arranged on the inner surface of the bag, and the necessary peripheral portion is heated and pressed to easily form the packaging bag. The micropores in the present invention are those provided by, for example, a needle or a laser, and an appropriate adhesive is used for a base material film in which micropores are provided in advance in positions that become peripheral portions, and this is laminated with an aluminum foil. A heat-adhesive film, which is the innermost layer, is laminated on the aluminum foil side of this laminated film using an adhesive. It is preferable to use low density polyethylene as the heat adhesive film. The aluminum foil thus obtained is used as an intermediate layer, a base film is laminated on one side, and a film having a heat-adhesive film laminated on the other side is used. To form. Alternatively, after forming the packaging bag, the heat-bonded portion is easily provided with fine holes in the base film layer by a needle or a laser so as not to damage the aluminum foil from the surface of the bag, thereby facilitating easy-open packaging of the present invention. You can get a bag. In the treatment, it is preferable to use a laser beam because the laser beam is reflected by the aluminum foil and is less likely to damage the aluminum foil.

The form of the packaging bag of the present invention is not particularly limited, and may be, for example, a gusset bag, a three-sided seal bag, a self-supporting bag, or the like. The cross-sectional structure of the laminated film of the packaging material used in the present invention is shown in FIG. In FIG. 1, the aluminum foil 1 is used as an intermediate layer, the base film 2 is laminated on one surface of the aluminum foil 1 with the adhesive layer 3 interposed therebetween, and the thermal adhesive film 4 is laminated on the other surface of the aluminum foil 1 with the adhesive layer 3 interposed therebetween. And when forming a packaging bag with such a laminated film, the micropore 5 is provided in the base material film of the peripheral part, or a base material film and a thermoadhesive film.

FIG. 2 is a view showing an example of forming the easy-open packaging bag of the present invention. In FIG. 2, aluminum foil 1
As an intermediate layer, the base film 2 is laminated on one surface of the laminated film with the adhesive layer 3 interposed therebetween, and the heat-adhesive film 4 is laminated on the other surface of the laminated film with the adhesive layer 3 interposed therebetween. Micropores 5 are provided in the material film layer (a). Then, by folding back the laminated film at the central portion to form a packaging bag, an easily openable packaging bag having fine holes in the peripheral portion of the packaging bag is obtained.

[0014]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples. Example 1 A thickness of 12 μm on one surface of an aluminum foil having a thickness of 7 μm
After laminating the biaxially stretched polyester film of No. 12 with a thickness of 12 μm of molten polyethylene as an adhesive, and directly laminating 40 μm of low density polyethylene on the opposite surface by extrusion film forming, a three-layer structure of polyester / aluminum foil / polyethylene Then, a heating needle was used to form a hole having a diameter of about 0.2 mm in only the base film so as to have a width of about 3 mm at a portion to be heat-bonded in the sealed packaging bag. Using this packaging material, a packaging bag having a width of 50 mm and a length of 85 mm was prepared by thermally adhering the three sides. The heat bonding width at this time is 5
mm. As a result of visually confirming the heat-bonded portion of the obtained packaging bag, the aluminum foil had a good appearance without cracks.

[0015]

As described above, according to the present invention, the base film and the heat-adhesive film are finely divided so that the peripheral edge of the packaging bag formed of the laminated film in which the aluminum foil is interposed is not scratched. By providing the scratches formed by the holes, an easily openable packaging bag having a good appearance can be obtained without cracking the aluminum foil. In addition,
When laminating the base film and the aluminum foil,
When molten polyethylene is used as an adhesive, when forming a hole with a needle, this polyethylene layer acts as a buffer and the needle does not damage the aluminum foil, and the hole in the base film can be reliably formed. .

[Brief description of drawings]

FIG. 1 is a sectional view of a packaging material used in the present invention.

FIG. 2 is an explanatory view showing an example of forming the easy-open packaging bag of the present invention.

[Explanation of symbols]

1 Aluminum foil 2 Base film 3
Adhesive layer (sealant) 4 Thermal adhesive film 5 Micropores

Claims (1)

[Claims] 1. A packaging material in which an aluminum foil is used as an intermediate layer, a base film is laminated on one surface of the aluminum foil, and a heat-adhesive film is laminated on the other surface of the bag so that the inner surface of the bag is the heat-adhesive film. An easily openable packaging bag, characterized in that in a hermetically sealed packaging bag formed by heat-adhering a necessary peripheral edge portion, micropores are provided in advance at least in a base material film at a portion to be heat-bonded at the peripheral edge portion.