JPH047944Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a packaging material that has the function of releasing internal gas to the outside when formed into a bag shape.

It is known that fermented foods such as natto and cheese, or roasted coffee beans and raw bread crumbs, generate carbon dioxide gas during storage, and this carbon dioxide gas causes the bag to break and the taste changes due to the generated gas, which may cause problems during storage. It is known to reduce effectiveness. The following methods are known for removing internally generated gases such as carbon dioxide gas.

○B. In-bag placement method with a drug that absorbs carbon dioxide gas. As the carbon dioxide absorbing material, there is known a method such as manufactured by Kemetron Corporation in the United States under the trade name Baralime, and the method shown in Japanese Patent Application No. 82781/1983.

○B Method using a valve. This valve system prevents oxygen and moisture from entering, keeps the internal pressure constant, and releases carbon dioxide gas.It is a product of Aroma Protection, a product of the German Robert Botschü Hesser Packaging Machinery Department.
Valve V-10 is known.

However, method (B) involves the risk of accidental ingestion because it is packaged with food, and method (B) requires large-scale machinery and equipment.

This invention solves these drawbacks by keeping the gas inside the bag or container constant, preventing the unique flavor of the food from scattering, releasing internally generated gases such as carbon dioxide, and preventing oxygen and moisture from entering from the outside. The purpose is to provide packaging materials that can

That is, the present invention includes a non-gas permeable outer layer film having slits, and a gas permeable inner layer film consisting of a heat sealable film or a laminated film having a heat sealable resin layer as the innermost layer.
This is a gas-releasing packaging material that is bonded with an adhesive applied except for the area around the cut.

Hereinafter, the present invention will be explained with reference to the drawings. Each of the drawings shows an embodiment of the present invention.

Figure 4 of the drawings is a plan view of a packaging bag made using the packaging material of the present invention. Although the cut is shown as a single solid line, the outer films touch or overlap each other in this area, and the cut has substantially no width. Therefore, there is almost no inflow or outflow of gas such as oxygen through the cuts.
FIG. 2a is a partially enlarged sectional view of the area around the cut at this time, and for convenience of explanation, the cut is drawn to have a width.

However, if this packaging material is made into a bag and a food that generates carbon dioxide gas, such as freshly roasted coffee beans, is hermetically sealed, the internal gas pressure increases due to the generation of carbon dioxide gas, causing the bag to expand.

The cut, which was closed at this time, widens as shown in Figure 2b, and a gap necessary for gas to pass through is secured. That is, a space surrounded by the inner film, the adhesive layer, and the outer film is created that communicates with the atmosphere, and the gas inside the bag passes through the inner film and is released into the atmosphere.

When the gas inside the bag is released and the gas pressure decreases, the inner film contracts, and the cut ' is closed, returning to the state shown in FIG. 2a.

As described above, the present invention releases internal gas by opening and closing the cut, and its operation is based on an extremely simple principle and does not require any special equipment. In addition, the intrusion of oxygen and water vapor from the outside can be prevented by using a non-gas permeable outer layer film, and by contacting the outside air only when the gas inside is released, and is normally blocked. extremely small.

Furthermore, an important point of the present invention is that a non-adhesive-uncoated portion is provided at the periphery of the cut in the non-gas permeable outer layer film. This adhesive-uncoated portion forms a space communicating with the atmosphere when the bag is inflated, ensuring contact of the gas-permeable film with the atmosphere and promoting gas release.

As the non-gas permeable outer layer film used in the present invention, vinylon film, ethylene-vinyl alcohol copolymer film, polyester film, nylon film, cellophane film coated with polyvinylidene chloride, aluminum film, etc. can be used. .

As the gas-permeable heat-sealable film, a heat-sealable film whose material itself is gas permeable, or a heat-sealable film in which gas permeability is imparted by providing a large number of holes can be used. Heat-sealable films whose materials themselves are gas permeable include polyethylene,
Films such as polypropylene can be used, and examples of films that have gas permeability by providing a large number of holes include polyethylene non-woven fabrics and polypropylene non-woven fabrics, as well as polyethylene films with perforations in the areas corresponding to the cuts mentioned above, polypropylene films, etc. , vinylon film, nylon film, etc. FIG. 3 is an enlarged cross-sectional view showing the vicinity of the cut of a packaging bag using a heat-sealable film as the inner layer film, in which the outer layer film is perforated at a portion corresponding to the cut.

As described above, the inner layer film can be formed of a heat sealable film, but a laminated film obtained by coating or laminating paper, cloth, nonwoven fabric, etc. with a heat sealable resin can also be used as the inner layer film. When a packaging material is operated using this laminated film as an inner layer film, the heat-sealable resin must be used as the innermost layer of the packaging bag. This heat-sealable resin can be made of the same material as the heat-sealable film described above, that is, polyethylene, polypropylene, nylon, or ethylene-vinyl acetate copolymer, with perforations formed in the portions corresponding to the breaks in the outer film. You can also put it in.

The outer layer film and the inner layer film can be laminated by dry lamination, hot melt lamination, wet lamination, or the like.

Fig. 4 is an explanatory diagram illustrating the process of laminating the outer film and the inner film by dry lamination and making cuts in the outer film. Coat. In the figure, the adhesive-coated areas are represented by dots, but as can be seen, the non-coated areas are formed linearly in the longitudinal direction of the outer film. Then, the solvent in the adhesive is removed and dried in a drying oven, and before the adhesive loses its adhesive strength, cuts are made in the non-coated portion using a rotary cutter.
In the figure, the cut is expressed as a dotted line for ease of viewing, but as explained in Figure 1, the cut does not have to be a dotted line, and the cut is cut into two pieces. good.

Then, before the adhesive loses its adhesive strength,
The inner layer film is laminated and crimped with a crimping roll to obtain the packaging material of the present invention.

In order to produce a package using the packaging material of the present invention, a known method such as a three-sided seal, a four-sided seal, a casette bag, a standing pouch, etc. may be used.

This invention makes it possible to release gases generated by food, such as carbon dioxide, to the outside in an extremely simple way without intruding atmospheric oxygen and water vapor, and without releasing the flavor of the food.
It is extremely useful in industry.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a plan view of a packaging bag made using the packaging material of the present invention; FIG.
FIG. 2b is a partially enlarged cross-sectional view of the area around the cut when the internal gas pressure increases, and FIG. 3 is a partially enlarged cross-sectional view of the area around the cut when a heat-sealable film with perforations is used as the inner layer film. FIG. 4 is an explanatory diagram of the process of manufacturing the packaging material of the present invention. ... cut (slit), ′ ... cut (slit) when gas is released, ... outer layer film,
...adhesive, ...inner layer film, ...space,
...gravure cylinder, ...drying oven, ...crimping roll, ...packaging material, ...rotary cutter.

Claims (1)

[Claims for Utility Model Registration] 1. A gas permeable film consisting of a non-gas permeable outer layer film having a slit and a heat sealable film or a laminated film having a heat sealable resin layer as the innermost layer, as described above. A gas-releasing packaging material that is bonded with a coated adhesive except for the area around the cut. 2. The gas-releasing packaging material according to claim 1, wherein the outer film layers are in contact with each other or overlap each other at the cut portion.