JPH11198967A - Inner bag of bag-in-box for dairy products - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inner bag for a bag-in-box of large capacity having high impact resistance and resistance to pin hole. SOLUTION: In the inner bag of bag-in-box for dairy products wherein an inside film 11 is laminated onto an outside film 12 and the outer peripheries of both the films are heat sealed, as the inside film 11 to be in contact with the contents of the bag, an additive-free linear low density polyethylene film is used and in the outside film 12, a biaxially oriented nylon film is used as an intermediate layer 12a and the layer 12a is sandwiched between linear low density polyethylene films 12b, 12c to form a laminated composite film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner bag of a large bag-in-box filled with a liquid or viscous dairy product.

[0002]

2. Description of the Related Art Conventionally, from the viewpoint of hygiene of contents, it is obligatory to use additive-free polyethylene as an inner bag of a bag-in-box for storing milk products such as fresh cream and milk. . And, in order to maintain the strength of the inner bag, mainly in order to maintain the burst strength, JP-A-7-2255, JP-A-7-187233,
The inner bag uses a co-extruded film of low-density polyethylene (LDPE) and high-density polyethylene (HDPE) as disclosed in JP-A-7-187234.

However, since additive-free polyethylene originally has low film strength such as tensile strength and pinhole resistance, it cannot be said that polyethylene is suitable for a large liquid container of a bag-in-box having a capacity of about 10 to 20 liters. In addition, high-density polyethylene used to have burst strength also has high rigidity, so it has strong tensile strength and puncture resistance, but lacks flexibility and has poor bending pinhole resistance. There is a problem that a pinhole is easily generated by vibration. Further, in the case of high-density polyethylene, since the film is hard, bag breakage is likely to occur at the seal edge portion due to the impact when dropped.

For this reason, for example, as shown in FIG. 3, the innermost layer (the side where the contents come in contact) has no LDPE (10%).
1), a non-doped LDPE (102) in the middle layer, and a non-doped LDP on both sides of non-doped HDPE (103) in the outermost layer
Although a triple bag made of a composite film laminated with E (104, 105) is used, it is still not perfect.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems relating to the inner bag of a large bag-in-box using non-added polyethylene, and has been made in view of impact resistance and pinhole resistance. An object of the present invention is to provide an inner bag of a large-capacity dairy product bag-in-box excellent in performance.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an inner bag of a dairy bag-in-box, which is formed by stacking two double films, each having an inner film and an outer film, and heat sealing the periphery. A non-added linear low-density polyethylene film is used for the inner film in contact with the outer film, and a biaxially stretched nylon film is used as an intermediate layer for the outer film, and a composite film obtained by laminating a linear low-density polyethylene film on both sides is used. This is the inner bag of the product bag-in-box.

[0007] As described above, according to the present invention, an additive-free linear low-density polyethylene film is used for the inner film in contact with the contents, and a biaxially stretched nylon film is used as the intermediate layer for the outer film. Since a composite film laminated with a low-density polyethylene film was used,
An inner bag with excellent impact resistance and pinhole resistance can be obtained. Further, since the additive-free resin is used for the inner film in contact with the contents, there is no problem in hygiene.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments. FIG. 1 is an explanatory sectional view showing an example of the layer constitution of the film for an inner bag of the present invention, and FIG. 2 is an explanatory plan view of an inner bag of a dairy bag-in-box produced using the inner bag. It is.

As shown in FIG. 1, the inner bag of the present invention comprises a double film (2) in which an inner film (11) provided on the side in contact with the contents and an outer film (12) located outside the inner film (12) are laminated. 10).

The inner film (11) is not allowed to contain additives such as antioxidants and the like, because the dairy product as the contents is in contact with the inner film (11). In the present invention, a film obtained by molding an additive-free linear low density polyethylene resin (LLDPE) by an inflation method or a T-die method is used. 50-10
Those having a thickness of about 0 μm can be suitably used.

The outer film (12) is provided for the purpose of protecting the inner film. The outer film (12) is required to have not only physical properties such as tensile strength but also pinhole resistance, drop impact resistance and the like. Is also required. Therefore, the thickness of the intermediate layer (12a) is 10 to 20
A biaxially stretched nylon film (ONy) having a thickness of about 30 μm is used on both sides (12b, 12c).
About LDPE was laminated by an extrusion laminating method, a dry laminating method or the like to obtain an outer film (12). Since the outer film (12) does not come into contact with the contents, additives such as an antioxidant may be added.

The inner film (11) and the outer film (1)
2) A spout (22) is formed in one of the double films by making the inner film surfaces of the double film (10) in which two sheets are stacked face each other, and heat sealing (21) is performed in a square shape. Make a bag. A cap is stopper-fitted to the spout (22) to form an inner bag. These spouts and caps are made of low density polyethylene (LDPE) with no additives
Is molded by an injection molding method.

[0013]

EXAMPLES Examples of the present invention will be described below more specifically. <Example 1> As an inner film (11), a non-addition grade LLDPE having a thickness of 75 µm was prepared.

As an intermediate layer (12a), a 15 μm thick O
Ny is prepared, and LLDPE having a thickness of 55 μm is provided on the side (12b) of the ONy which is in contact with the inner film, and LL having a thickness of 35 μm is provided on the side (12c) which is not in contact with the inner film.
DPE was laminated by extrusion lamination to form an outer film (12). Additives such as antioxidants are added to the material of the outer film.

A double film (10) in which two inner films and an outer film are superposed on each other, and a spout (22) made of LDPE containing no additive is formed in one of the two films with the inner film surfaces facing each other. At the same time, 58cm × 5
The periphery was heat-sealed (21) into a 9 cm substantially square shape to make a bag. An LDPE-free cap was plug-fitted into the spout to produce a 58 cm × 59 cm inner bag containing 18 liters.

<Comparative Example 1> A composite film (total thickness: 60 μm) obtained by laminating both sides of a non-additive grade HDPE with a non-additive grade LDPE as an inner layer (side in contact with the contents) was used as an intermediate layer film. Additive grade LDPE on both sides of additive free grade HDPE
Composite film laminated with PE (total thickness 60μm)
And a composite film (total thickness: 130 μm) obtained by laminating an additive-free grade LDPE and an additive-free grade HDPE as an outer layer film.

These inner layer film, intermediate layer film,
The inner film surfaces of the three-layer film in which the outer layer films were stacked were opposed to each other, a spout was formed in one of the three-layer films, and the periphery was heat-sealed into a 58 cm × 59 cm square to form a bag. An LDPE-free cap was plugged and fitted to the spout to produce an inner bag with dimensions of 58 cm × 59 cm containing 18 liters.

The two kinds of bag-in-boxes thus produced were filled with 18 liters of cold water at 5 ° C., and a drop test and a vibration test were performed according to the following methods and conditions. Table 1 shows the results. Drop test, drop in the direction of the bottom seal ‥ Drop five times repeatedly from a height of 1 m so that the bottom seal of the inner bag (the lower seal in FIG. 2) first hits the concrete floor (Example 1). The inner bag is dropped once from a height of 0.5 m so that the bottom seal of the inner bag first contacts the concrete floor (Comparative Example 1). Drop in side seal direction ‥ Side seal of inner bag (Fig. 2
In Example 1, the material is repeatedly dropped five times from a height of 0.5 m so that the left or right side of the seal) first hits the concrete floor (Example 1). With the side seal of the inner bag hitting the concrete floor first,
It is dropped once from a height of m (Comparative Example 1). Horizontal drop on the floor 方向 Bottom of inner bag (in FIG. 2,
5) Repeat from the height of 0.5m so that the side with no spout attached first hits the concrete floor.
Drop it once (Example 1). The inner bag is dropped once from a height of 0.5 m such that the bottom surface of the inner bag first contacts the concrete floor (Comparative Example 1). The number of samples (n) under each condition was 2.

Vibration test: Each inner bag was 273 in inner method.
mm × 273 mm × 274 mm in a cardboard case, amplitude: 2.2 mm, vibration frequency: 15 H with a vibration tester
Vibration was applied for 60 minutes under the conditions of z, vibration direction: vertical.
The number of samples (n) under each condition was 4.

[0020]

[Table 1]

Considering from Table 1, the inner bag using the non-added LLDPE for the inner (wetted) side film (Example 1) is as follows.
It was found that both the drop test and the vibration test were remarkably superior to the inner bag (Comparative Example 1) using LDPE / HDPE without additives for the inner film.

[0022]

As described above, according to the present invention, the seal strength and the pinhole resistance are improved by changing the inner film from an additive-free low-density polyethylene to an additive-free linear low-density polyethylene. The use of a composite film in which a linear low-density polyethylene was laminated on both sides of a biaxially stretched nylon film as the outer film improved drop impact strength and pinhole resistance. Since the inner film is an additive-free linear low-density polyethylene, there is no problem in the hygiene of the contents.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration explanatory view showing an example of a layer configuration of an inner bag film of the present invention.

FIG. 2 is an explanatory plan view of an inner bag of a bagon box manufactured using the inner bag of the present invention.

FIG. 3 is an explanatory sectional view showing a layer structure of a film of an inner bag of a conventional dairy bag box.

[Explanation of symbols]

 10 Double film 11 Inner film 12 Outer film 12a Intermediate layer, ONy 12b, 12c LLDPE 20 Inner bag of bagon box 21 Seal part 22 Outlet 101, 102 , 104, 105 ‥‥ LDPE 103 ‥‥ HDPE

Claims (1)

[Claims] 1. An inner bag of a dairy product bag-in-box in which a double film in which two inner films and an outer film are stacked and the periphery thereof is heat-sealed is not added to the inner film in contact with the contents. A dairy product bag comprising a composite film in which a linear low-density polyethylene film is used, a biaxially stretched nylon film is used as an intermediate layer for the outer film, and a linear low-density polyethylene film is laminated on both sides of the intermediate film. Inner bag of inbox.