JP6131040B2 - Laminate shrink film - Google Patents

Description

  The present invention relates to a laminate shrink film. More specifically, the present invention relates to a laminate shrink film used for packaging in a state where the packaging film is in close contact with the packaging article.

  When selling products such as food, confectionery, books, cosmetics, and pharmaceuticals, the products are provided and sold in a state of being packaged with a plastic film or the like in order to prevent the product from being soiled. There are various types of packaging for such packaging. When automatic packaging is performed on a production line, for example, shrink packaging (heat shrink packaging) can be mentioned.

  Shrink wrapping (heat-shrink wrapping) allows (1) packaging with a film in close contact with the packaged article regardless of the shape of the packaged article, etc. (2) Packaging with multiple articles fixed and held together (3) It has the merit that automation of packaging is easy. For this reason, shrink wrapping has been increasingly used for packaging various articles to be packaged.

By the way, even in a shrink-wrapped product, various designs and characters are printed on the packaging film itself in order to improve the appearance and the advertising effect. This printing is designed in consideration of the appearance when the film is thermally contracted.
In addition, light-shielding ink or the like may be printed in order to prevent the inner packaged article from being deteriorated by light.

  On the other hand, when shrink-wrapping, the film is heat-sealed in order to seal the packaged article with the film. Thermal fusion is usually performed at the same time as the film is cut by a known sealing machine such as a fusing seal or a palm seal, but printing is performed on the surface located outside when the packaged article is packaged with the film. In this case, the printing ink melts and adheres to the sealing machine at the time of sealing, which may contaminate the sealing machine. On the contrary, when printing is performed on the surface located inside when the article to be packaged is packaged with the film, the printing ink becomes an obstacle and the heat fusion between the films is inhibited.

For this reason, in the shrink-wrap film, the printing design is adjusted so that there is no printing ink in the portion to be heat-sealed. Then, there is a problem that the design of the product is not good because the print design is limited and there is no printing at the heat-sealed portion.
Further, even when the film is provided with a light-shielding property, there is a problem that a sufficient light-shielding property cannot be imparted because printing cannot be performed on the heat-sealed portion.

  As a method for preventing such a problem, it is conceivable to prevent the printing ink from being exposed on the surface. For example, in a shrink label or the like, a technique for printing on the back surface of the shrink film (that is, the surface on the heat shrink sheet side) as a laminated sheet by laminating the shrink film and the heat shrink sheet is developed (for example, Patent Documents 1 to 3). 6).

Japanese Utility Model Publication No. 60-62936 Japanese Utility Model Publication No. 63-43722 Japanese Patent Laid-Open No. 3-219952 JP-A-4-41233 Japanese Patent Laid-Open No. 5-204312 JP-A-8-300547

  However, since the techniques of Patent Documents 1 to 6 are techniques related to a sheet used for a shrink label and not a sheet used for shrink wrapping to be sealed by heat fusion, the problem of heat fusion as described above. There is no consideration for.

  At present, there is no film printed up to the part to be heat-sealed in the film used for shrink wrapping, and such a film is desired.

  In view of the above circumstances, an object of the present invention is to provide a laminate shrink film that can be printed up to a portion to be heat-sealed and can improve the appearance and function of a packaged product.

The laminated shrink film of the first invention is a film used in a package formed by heat- sealing films, and the film has a pair of shrink films having heat shrinkability, and the pair of shrink films It is formed by bonding shrink films together with an adhesive. A printed layer is formed on the surface of the other shrink film on the other shrink film side, and the printed layer contains a chlorinated polypropylene resin. The laminate shrink film of the second invention is used for a package formed by heat-sealing films together, which is also formed on a portion to be heat-sealed when forming a package. The film has a pair of shrink films having heat shrinkability, and the pair of shrink films are in contact with each other. A printed layer is formed on the surface of the other shrink film side of the one shrink film, and the printed layer is a coat layer containing a chlorinated polypropylene resin on the surface. Is formed on a portion to be heat-sealed when the package is formed .

According to the first invention, since the printing layer is located between the pair of shrink films, it is possible to prevent the sealing machine from being soiled by the material of the printing layer even if the film is heat-sealed. Moreover, since the printing layer material contains a chlorinated polypropylene resin, when the laminated shrink films of the present invention are heat-sealed, even if the printing layer is formed on that portion, the heat-sealing is firmly performed. can do. Therefore, since it is not necessary to make the area to be heat-sealed as a non-printing area during the overlap wrapping, the degree of freedom in designing the print layer is increased and the entire surface can be printed. In addition, when the overlap packaging is performed, there is printing on the entire surface of the package. Therefore, if the light shielding ink is printed, the light shielding property can be improved. Moreover, since the part without printing cannot be performed, the appearance of the package can be improved.
According to the second invention, since the printing layer is located between the pair of shrink films, it is possible to prevent the sealing machine from being soiled by the material of the printing layer even if the film is heat-sealed. Moreover, since the surface of the printing layer contains a coating layer made of a chlorinated polypropylene resin, when the laminate shrink film of the present invention is heat-sealed, even if the printing layer is formed in that portion, it is strong. Can be heat-sealed. Therefore, since it is not necessary to make the area to be heat-sealed as a non-printing area during the overlap wrapping, the degree of freedom in designing the print layer is increased and the entire surface can be printed. In addition, when overlap-wrapped, it can be firmly heat-sealed in any region of the film, so there is printing on the entire surface of the package. Can be improved. Further, if the entire surface is printed, a portion without printing cannot be formed, so that the appearance of the package can be improved.

It is a schematic sectional explanatory drawing of the laminate shrink film 1 of this embodiment. It is a schematic explanatory drawing of the manufacturing equipment of the laminate shrink film 1 of this embodiment. It is a schematic explanatory drawing of the operation | work which manufactures package MP using the laminate shrink film 1 of this embodiment.

  The laminate shrink film of the present invention is a film used for shrink-wrapping an article to be packaged, and can improve the appearance, light-shielding function, etc. of the shrink-wrapped product.

  The article to be packaged that is shrink-wrapped by the laminate shrink film of the present invention is not particularly limited. For example, food, confectionery, books, cosmetics, pharmaceuticals, and the like can be mentioned, but the invention is not limited to these.

  In addition, the laminate shrink film of the present invention is very thin (about 19.5 to 35 μm) compared to the packaged article, and the film and each layer constituting the laminate shrink film are also very thin. The relative dimensions of the film to be packaged and the like, the thickness of the laminated shrink film cross section, the thickness of each layer, and the like do not necessarily match the actual relative dimensions.

  Moreover, although the laminate shrink film of this invention has at least one pair of shrink film so that it may mention later, the shrink film which comprises a laminate shrink film is not limited to two sheets. For example, the laminate shrink film of the present invention includes a laminate of three or more shrink films. In addition, when three or more shrink films are laminated, it is not necessary to provide a printing layer and an adhesive layer between all the shrink films, and only an adhesive layer may be provided. .

(Laminated shrink film)
The laminate shrink film 1 of this embodiment will be described.

  As shown in FIG. 1, the laminate shrink film 1 of this embodiment includes a pair of shrink films 1a and 1b, and a printing layer 2 and an adhesive layer 3 formed between the pair of shrink films 1a and 1b. Have. That is, in the laminate shrink film 1 of this embodiment, the printing layer 2 is sandwiched between a pair of shrink films 1a and 1b.

  For this reason, in the case of the laminate shrink film 1 of this embodiment, in the manufacturing process of the package MP as will be described later, when the films are overlapped and fused or heat-sealed, Even if the printing layer 2 exists, the material such as the printing ink of the printing layer 2 does not directly contact the sealing machine. That is, since a material such as printing ink does not adhere to the sealing machine, the sealing machine or the like does not get dirty even if there is printing on the heat-sealed portion.

Moreover, if there is printing at the portion to be heat-sealed, printing ink or the like may inhibit the heat-sealing.
However, in the laminate shrink film 1 of the present embodiment, the printing layer 2 is made of a material containing chlorinated polypropylene resin, so that even if the printing layer 2 is present in the heat-sealed portion, the heat-sealing is firmly performed Can be made.

  Therefore, in the laminate shrink film 1 of the present embodiment, the portion to be heat-sealed does not need to be a non-printing area during shrink wrapping (for example, overlap wrapping). In addition, the entire surface can be printed. Therefore, it is possible to improve the appearance and the light-shielding function of the product that is wrapped and the like.

  Even when overlapping packaging is performed, it is possible to print the entire surface of the laminate shrink film 1. Then, since it will be in the state with printing on the whole surface of the package MP which carried out the overlap wrapping, if light-shielding ink is printed, light-shielding property can be improved. Moreover, since there is no printed part in the packaged article M, the appearance of the package MP can be improved.

Below, each member of the laminate shrink film 1 of this embodiment is demonstrated.
In the following description, among the pair of shrink films 1a and 1b, the shrink film 1a is disposed outside the packaging body MP, and the shrink film 1b is disposed inside the packaging body MP, that is, on the side in contact with the packaged article M. The case where it will be described.

(Shrink film)
First, the pair of shrink films 1a and 1b are formed of a resin that has heat shrinkability and can be heat-sealed in a state where the films are stacked. That is, the pair of shrink films 1a and 1b is thermally melted in any state of the state in which the shrink films 1a are overlapped, the state in which the shrink films 1b are overlapped, and the state in which the shrink film 1a and the shrink film 1b are overlapped. It can be worn.

  In addition, a pair of shrink film 1a, 1b should just have the above properties, and is not specifically limited. Examples thereof include a film obtained by uniaxially or biaxially stretching a resin film such as polypropylene (PP) or polyethylene terephthalate (PET).

  Further, the thickness of the pair of shrink films 1a and 1b is not particularly limited, but for example, a thickness of about 9.5 to 15 μm is preferable. If the pair of shrink films 1a and 1b are formed to such a thickness, even if the printing layer 2 and the adhesive layer 3 are combined, the thickness of the laminate shrink film 1 of this embodiment is at most 19.5 to 35 μm. It will be about. Then, since it becomes a thickness comparable as the single layer film currently used for the conventional shrink packaging, it can be used also for an overlap packaging like a single layer film. In addition, since the two shrink films are overlapped, there is an advantage that the strength can be made stronger than the film of the conventional shrink packaging and the packaging is not easily broken.

  Furthermore, it is preferable that the pair of shrink films 1a and 1b be formed with the same resin and the same thickness because the shrinkage ratios of both the shrink films 1a and 1b can be made substantially equal when thermally contracted. Further, it is preferable because curling does not occur when the laminate shrink film 1 is thermally contracted.

(Print layer 2)
The printing layer 2 is a layer formed on the back surface of the shrink film 1a. The printing layer 2 is formed by applying a printing ink containing a pigment, a solvent, and a binder to the back surface of the shrink film 1a by a method such as gravure printing or flexographic printing.

As described above, in the laminate shrink film 1 of the present embodiment, the printing ink for forming the printing layer 2 contains chlorinated polypropylene resin as a binder. However, except for this point, the printing for forming the printing layer 2 is performed. Ink and the like are composed of known raw materials used in normal printing.
The binder may be a mixture of a chlorinated polypropylene resin and a commonly used resin binder, or only a chlorinated polypropylene resin may be used as the binder.

  Further, the ratio of mixing a resin binder containing chlorinated polypropylene resin or chlorinated polypropylene resin with the printing ink is preferably about 1.5 to 17%. When there are too few resin components in printing ink, the viscosity of printing ink will fall and the problem that peeling of printing will arise easily will arise. On the other hand, if the resin component in the printing ink is too large, the viscosity increases and printing becomes difficult.

(Example in which coat layer 4 is provided)
Further, as shown in FIG. 1 (B), a printing layer 2 is formed by printing a design or characters using normal printing ink, and a resin containing chlorinated polypropylene resin or chlorinated polypropylene resin on the surface thereof. The coat layer 4 may be formed by coating. That is, the coat layer 4 may be provided so as to be positioned between the print layer 2 and the adhesive layer 3. In this case, since it is not necessary to include chlorinated polypropylene resin in the material such as printing ink for printing the designs and characters, the designs and characters can be printed in the same way as normal printing, so printing is easy. .

  In particular, when shrink wrapping is performed, the coat layer 4 is provided on the entire surface of the shrink film 1a, so that any region of the film can be firmly heat-sealed. Then, since it is possible to print on the entire surface of the shrink film 1a, the light shielding property can be improved by printing the light shielding ink on the entire surface. Further, if the entire surface is printed, a portion without printing cannot be formed, so that the appearance of the package MP can be improved.

(Adhesive layer 3)
The adhesive layer 3 is a layer formed on the back surface of the shrink film 1b. The adhesive layer 3 is formed, for example, by applying an adhesive such as a urethane adhesive or a chlorinated polyolefin adhesive to the back surface of the shrink film 1b by a method such as gravure coating.

In addition, the application amount of the adhesive layer 3 is not particularly limited, but for example, it is preferable to apply 1 g / m ² or more.

  Moreover, it is preferable to apply | coat an adhesive agent after performing the surface treatment for improving adhesiveness with an adhesive agent to the shrink film 1b. Examples of the surface treatment include corona discharge treatment and plasma treatment.

(Manufacturing method of the laminate shrink film 1 of this embodiment)
Next, a method for producing the laminate shrink film 1 will be described.
In FIG. 2, symbols MR1 and MR2 are original rolls around which the above-described shrink film 1a and shrink film 1b are wound. Reference sign SR denotes a product roll around which the manufactured laminate shrink film 1 is wound.
In addition, the shrink film 1a wound up by the raw fabric roll MR1 is a film in which the printing layer 2 has already been formed on the surface. Of course, when the shrink film 1a is the laminate shrink film 1 of FIG. 1B, it goes without saying that the coat layer 4 is also formed on the surface of the print layer 2.

  First, the shrink film 1a is unwound from the raw roll MR1 and supplied to the laminating apparatus RP.

  On the other hand, when the shrink film 1b is unwound from the raw roll MR2, the surface treatment is performed on the back surface (lower surface in FIG. 2) by the surface treatment device CP.

The shrink film 1b surface-treated by the surface treatment device CP is supplied to the adhesive application device GR, and the adhesive is applied to the back surface, that is, the surface-treated surface, so that the adhesive layer 3 is formed.
In addition, in order to apply | coat an adhesive agent uniformly to the shrink film 1b, it apply | coats in the state melt | dissolved in the solvent. What is necessary is just to use the solvent used in this case according to an adhesive agent.

  The shrink film 1b on which the adhesive layer 3 is formed is supplied to the drying device DP. In the drying device DP, the shrink film 1b is heated to remove the solvent contained in the adhesive layer 3 formed on the shrink film 1b.

  Then, the shrink film 1b that has passed through the drying device DP is supplied to the laminating device RP, and is laminated and bonded to the shrink film 1a. Specifically, in the laminating apparatus RP, the surface of the shrink film 1b on which the adhesive layer 3 is formed and the surface on which the printed layer 2 of the shrink film 1a is formed are pressed together. Then, both sheets are adhere | attached with the adhesive agent of the adhesive bond layer 3, and the laminate shrink film 1 is formed.

(Method for producing package MP)
Below, the process of manufacturing the package MP shrink-wrapped by the laminate shrink film 1 of this embodiment is demonstrated easily.

  In the process of manufacturing the package MP, the laminate shrink film 1 of the present embodiment is a continuous belt-like web, and is folded into two so that a space is formed between the upper and lower films Fa and Fb in the transport process. It is done. Then, the packaged article M is supplied to the space between the upper and lower films Fa and Fb, and the packaged article M is sandwiched between the upper and lower films Fa and Fb (see FIG. 3A).

  When the article to be packaged M is sandwiched between the upper and lower films Fa and Fb, the laminate shrink film 1 is heated and cut by a known fusing seal at portions located before and after the article to be packaged M in the transport direction. . At this time, the portion cut by the fusing seal is fused and the upper and lower films Fa and Fb are heat-sealed to form a heat-sealed portion HS. At the same time, the opening edges s of the upper and lower films Fa and Fb are heat-sealed to form a heat-sealing part HS. That is, the upper and lower films Fa and Fb are heat-sealed with each other in three directions surrounding the packaging article M excluding the portion where the laminate shrink film 1 is bent, and the heat-sealed portion HS is formed and sealed. That is, the pre-shrinkage packaging body BS in which the packaging article M is sealed with the laminate shrink film 1 is formed (see FIG. 3B). And as above-mentioned, the laminate shrink film 1 has the printing layer 2 containing the chlorinated polypropylene resin, or the coating layer 4 of the chlorinated polypropylene resin is formed. For this reason, the upper and lower films Fa and Fb are firmly heat-sealed in the heat-sealing part HS.

  The pre-shrink wrapping body BS formed as described above is conveyed by a conveyor or the like and supplied to a heating tunnel or the like. Then, since the laminate shrink film 1 is shrunk by heating when passing through the heating tunnel or the like, a package MP in which the laminate shrink film 1 is in close contact with the surface of the packaged article M can be formed (FIG. 3 (C)).

  The laminate shrink film of the present invention is suitable for a film for overlapping packaging of articles to be packaged such as food, confectionery, books, and medicines.

1 Laminate Shrink Film 1a Shrink Film 1b Shrink Film 2 Print Layer 3 Adhesive Layer 4 Coat Layer

Claims (2)

A film used in a package formed by heat-sealing films,
The film
It has a pair of shrink films having heat shrinkability, and is formed by bonding the pair of shrink films together with an adhesive.
A printed layer is formed on the surface of the other shrink film on the other shrink film side,
The printed layer is
Contains chlorinated polypropylene resin ,
A laminated shrink film, which is also formed on a portion to be heat-sealed when forming a package . A film used in a package formed by heat-sealing films,
The film
It has a pair of shrink films having heat shrinkability, and is formed by bonding the pair of shrink films together with an adhesive.
A printed layer is formed on the surface of the other shrink film on the other shrink film side,
The printed layer is
A coat layer containing chlorinated polypropylene resin is formed on the surface ,
A laminated shrink film, which is also formed on a portion to be heat-sealed when forming a package .

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