JP2700235B2 - Heat shrink wrapping method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-shrinkable packaging method using a heat-shrinkable film, and more particularly to a heat-shrinkable packaging method suitably used for obtaining a heat-shrinkable package having excellent airtightness.

[0002]

2. Description of the Related Art Conventionally, as a shrink wrapping method, an object to be wrapped is covered with a heat shrinkable film, an opening is sealed, and then the heat shrinkable film is passed through a heat shrink tunnel or blown with hot air. A so-called heat shrink packaging method for heat shrinking a film is known. This heat shrink wrapping method is widely used because of its excellent economy, workability, and high speed. By the way, when this method is used for heat shrink wrapping that covers the entire surface of an article to be wrapped, air in the package covered with the heat shrinkable film must be discharged to the outside during heat shrink wrapping. Pre-opened several small holes on the surface of the heat-shrinkable film, or
It has been common practice to degas the air inside the package in advance and then heat shrink the package.

However, when a heat-shrinkable film having a small hole is used for packaging food or the like, air, moisture, bacteria, and the like enter the package through the small hole and oxidize and discolor the food to be packaged. There was a problem that rot and the like occurred, and storage could not be performed for a long time. Further, the heat-shrinkable package having small holes in the heat-shrinkable film also has a problem that a bag is easily broken from the small holes during transportation or the like. In order to solve such a drawback, a method is used in which a heat-shrinkable film is heat-shrink-wrapped in a state where a punch hole for air discharge is opened, and the punch hole is closed with an adhesive label (actually, Kosho 50
-29007) has been proposed. Although this method is effective in solving the above-mentioned drawbacks, it is difficult to automatically attach a label to a position where the punch hole is closed, and it is necessary to pack a label one by one for each package. There was a problem that the cost would be expensive.

[0004] A heat-shrinkable packaging method is disclosed in which a moisture-proof sheet is attached to a soft bag, and a packaging bag having an air outlet provided in a heat-shrinkable film is provided at the position of the moisture-proof sheet (Japanese Utility Model Application Laid-Open No. 63-14442). ) Has also been proposed. This method, the moisture-proof sheet attached to the soft bag, between the heat-shrinkable film, when heat shrink packaging, the air between the heat-shrink film and the soft bag is degassed and exhausted, when the packaging is completed, The portion of the air discharge hole on the moisture-proof sheet also adheres to the heat-shrinkable film, and the outside air does not flow from the periphery of the air discharge hole into the soft bag. It has.

However, such a heat-shrinking method uses a double-packaged bag composed of a soft bag and a heat-shrinkable film, so that the packaging operation is complicated and the packaging cost is high. In addition, although the air between the soft bag and the heat shrinkable film can be degassed, there is a drawback that it is difficult to deaerate and discharge the air between the soft bag and the package, and a moisture-proof sheet is attached to the soft bag. A heat-shrink wrapping step and a heat-shrink wrapping step, in which a heat-shrinkable film is positioned at the position of the moisture-proof sheet.
There has been a problem that the number of packaging work steps increases and complicated packaging management is required.

Further, the method of performing heat shrink packaging after evacuating the air in the package has the problem that not only the packaging apparatus is expensive, but also high-speed packaging cannot be performed, and the packaging cost increases.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and to provide a heat-shrinkable package which is excellent in airtightness and which does not easily break during transportation or the like by a simple process at a low cost. It is an object of the present invention to provide a heat-shrinkable packaging method that can be used.

[0008]

The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, the heat-shrinkable film has, for example, one row or two or three rows of adjacent small holes for air discharge. It is found that the above problem can be solved by inserting a band-shaped film between the object to be packaged and the heat-shrinkable film to heat-shrink the film so as to close the small holes, When a heat-shrinkable film is used as the film, it is possible to obtain a heat-shrinkable package having a good packaging finish, and that a hot-melt adhesive or a pressure-sensitive adhesive is applied to a surface of the belt-shaped film that contacts the heat-shrinkable film. That a heat-shrinkable package with excellent airtightness can be obtained,
Furthermore, they found that if a film having gas barrier properties was used as the heat-shrinkable film, the packaged product could be stored for a long period of time, and the present invention was completed.

That is, according to the present invention, in a heat shrink wrapping method for wrapping an article to be wrapped 1 using a heat shrinkable film 2, the heat shrinkable film 2 is provided with small holes 3 for discharging air. While inserting the belt-shaped film 4 between the packaged object 1 and the heat-shrinkable film 2 so as to close the small holes, the packaged object 1 is wrapped with the heat-shrinkable film 2 and then the opening is sealed to seal the open portion. A heat shrink wrapping method is provided, which comprises heating after being covered. In addition, the heat shrinkable packaging method is provided, wherein the heat shrinkable film 2 is provided with the air discharge small holes 3 arranged in one row or two or three rows adjacent to each other. The heat-shrinkable packaging method is provided, wherein a hot-melt adhesive or a pressure-sensitive adhesive is applied to the surface of the film 4 that contacts the heat-shrinkable film 2 on the surface that contacts the heat-shrinkable film 2,
Further, the heat-shrinkable packaging method is provided, wherein the heat-shrinkable film 2 is a heat-shrinkable film having a gas barrier property. Further, the heat-shrinkable film is used as the belt-shaped film 4. Is provided.

Hereinafter, the heat shrink wrapping method of the present invention will be specifically described. In the heat shrink wrapping method of the present invention, the heat shrinkable film 2 is provided with the small holes 3 for air discharge, and the heat shrinkable film 2 and the packaged object 1 are arranged so that the rows of the small holes 3 are completely closed. The package 1 is wrapped with the heat-shrinkable film 2 and the open portion is wrapped by a method such as a fusion seal such as a fusing seal, a lap seal, or an electrostatic seal. The object 1 is wrapped and passed through a heat shrink tunnel, or guided to a packaging machine provided with a heating means such as blowing hot air. How to

In the heat-shrinkable packaging method of the present invention, the small holes 3 provided in the heat-shrinkable film 2 are preferably arranged in one row or two or three rows adjacent to each other. Is preferred. Small hole 3 is adjacent 3
If they are arranged in rows or more, the width of the band-shaped film 4 that closes the small holes 3 needs to be increased, so that the aesthetic appearance of the heat-shrinkable package deteriorates and is uneconomical. Further, if the arrangement of the small holes 3 is far from the linear shape, the width of the band-shaped film 4 closing the small holes needs to be widened as described above, so that the appearance of the heat-shrinkable package deteriorates. And it is uneconomical. The number and size of the small holes may be appropriately selected according to the degree of air discharge during heat shrinkage. Further, if the small holes 3 provided in the heat-shrinkable film 2 are perforated, the bag can be broken through the small holes when opening the heat-shrinkable package.

Further, the surface of the belt-shaped film 4 in contact with the heat-shrinkable film 2 in the method of the present invention is easily adhered to the heat-shrinkable film 2 by heating at the time of heat-shrink packaging such as a hot-melt adhesive or an adhesive. When the coating agent is applied, the pores 3 are closed well, and excellent airtightness is obtained.

FIG. 1A is a perspective view showing one example of a heat-shrinkable package obtained by the method of the present invention. FIG. 1 (b)
FIG. 2 is a cross-sectional view taken along line AA of FIG. An article to be packaged 1 is covered with a heat-shrinkable film 2 having small holes 3 arranged in a line, and is further heat-shrink-wrapped in a state in which an opening is closed by a fusing seal 5. Further, a row of small holes 3 provided in the heat-shrinkable film 2 is closed by a band-shaped film 4 inserted between the packaged object 1 and the heat-shrinkable film 2. If a hot melt adhesive or the like is applied to the surface of the belt-shaped film 4 that contacts the heat-shrinkable film 2, the belt-like film 4 is not heat-sealed during packaging.
And the heat-shrinkable film 2 are adhered to each other, so that the airtightness is further improved.

The heat-shrinkable film 2 used in the present invention is a film that shrinks by heating, and is used for heat-shrinkable packaging such as a single-layer film of polypropylene, polyethylene, vinyl chloride or the like or a laminated film based on these resins. The film to be used is used. When a film having a gas barrier property is used as the heat-shrinkable film 2, it is possible to store a packaged object such as food for a long period of time. As the heat-shrinkable film having gas barrier properties, a single-layer film of polyamide, polyethylene terephthalate, polyvinylidene chloride or the like, or a multilayer in which a resin layer of polyvinylidene chloride or polyvinyl alcohol and another resin layer are laminated. Films and the like are preferred. The heat-shrinkable film 2 is preferably one that can be fused with the band-shaped film 4 by a seal such as a fusing seal or a welded seal from the viewpoint of packaging workability. Those that easily occur are preferred.

The strip film 4 may be heat-shrinkable or non-heat-shrinkable, and may be a single-layer film or a multilayer film. In addition, a multilayer film that easily causes blocking with the heat-shrinkable film 2 due to heating at the time of heat-shrink wrapping also shows good blocking of the small holes 3 and is effective in improving airtightness. Further, when the belt-shaped film 4 is heat-shrinkable, it may be the same film as the heat-shrinkable film 2 or another film. When the band-shaped film 4 is a film having heat shrinkability, the adhesion between the band-shaped film 4 and the heat-shrinkable film 2 in the heat-shrinkable package is beautiful, and the packaging finish is good. Especially,
If the heat shrinkage in the length direction of the belt-shaped film 4 and the heat shrinkage in the small hole row direction of the heat shrinkable film 2 are almost the same, the packaging finish is better.
It is preferable that the band-shaped film 4 can be fused to the heat-shrinkable film 2 by a seal such as a fusing seal or a welding seal from the viewpoint of packaging workability. Further, the band-shaped film 4 may be printed with a bar code, a mark for opening, or the like.

The width of the strip film 4 is preferably 2 cm to 10 cm. If the film width is less than 2 cm, it is difficult to close the row of small holes, and if the film width exceeds 10 cm, the packaging finish will be unsightly.
Further, it is a matter of course that the rolled film may be used as the belt-shaped film 4 separately from the heat-shrinkable film 2.

[0017]

According to the heat shrink wrapping method of the present invention, when heat shrinking is performed by a heat shrink tunnel or the like, first, the air inside the package expands and only the heat shrinkable film swells. There is a gap between them. Then, the heat-shrinkable film is shrunk while discharging the air in the package from the arranged small holes to the outside. Further thereafter, the band-shaped film provided between the object to be packaged and the heat-shrinkable film so as to close the small holes closes the heat-shrinkable film and closes the small holes,
In addition, the heating during the heat shrinkage causes the strip film and the heat shrinkable film to block or adhere to each other, thereby closing the small holes more completely, increasing the airtightness, and completing the packaging. .

[0018]

As described above, the heat shrink wrapping method of the present invention exhibits good airtightness because the strip film is used to close the small holes for discharging air during heat shrinkage. For this reason, products that are easily affected by oxygen and moisture can be stored for a long period of time. In addition, since the small holes are covered with a band-like film, troubles such as breakage of the bags from the small holes during transportation or the like are reduced.
In addition, since packaging can be easily performed at high speed, packaging cost can be reduced. In the method of the present invention, in the packaging operation, the heat-shrinkable film and the band-shaped film are simply overlapped and directly wrapped on the wrapped object, and then the wrapped wrapped object is subjected to heat shrinkage, fusion, etc. by heating. Only through the process, packaging with extremely good airtightness and excellent appearance can be easily performed.

[Brief description of the drawings]

FIG. 1 (a) is a perspective view of a heat-shrinkable package obtained by a heat-shrinkable packaging method of the present invention. (B) is a sectional view taken along line AA of (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Packaged matter 2 Heat shrinkable film 3 Small hole 4 Strip film 5 Fusing seal

Claims (5)

(57) [Claims] In a heat-shrinkable packaging method for packaging an article to be packaged using a heat-shrinkable film, a small hole for discharging air is provided in the heat-shrinkable film so that the small hole is closed. The strip-shaped film 4 is inserted between the package 1 and the heat-shrinkable film 2 while the package 1 is
A heat shrink wrapping method comprising: wrapping, then sealing by covering an open portion, and then heating. 2. The heat-shrinkable packaging method according to claim 1, wherein the heat-shrinkable film 2 is provided with small holes 3 for air discharge arranged in one or two or three adjacent rows. 3. A hot-melt adhesive or a pressure-sensitive adhesive is applied to the surface of the strip-shaped film 4 that contacts the heat-shrinkable film 2 on the surface that contacts the heat-shrinkable film 2. Heat shrink wrapping method. 4. The heat-shrinkable packaging method according to claim 1, wherein the heat-shrinkable film 2 is a heat-shrinkable film having gas barrier properties. 5. The heat-shrinkable packaging method according to claim 1, wherein a heat-shrinkable film is used as the strip film 4.