JPH07206040A - Bag body for germless bag-in-box of beverage - Google Patents

Abstract

PURPOSE:To obtain a bag body for a germless bag-in-box of beverages, which is easily produced in a low cost. CONSTITUTION:The molten resin is extruded tubularly from a circular die equipped at the front end of an extruder as two upper and lower innermost layer films 13, 13 in superposed two upper and lower PE film laminated layers 2a, 2b, regarding a bag body 1 for a bag-in-box of beverages. And at the same time, germless air is ejected in the tube to swell it and the front and tail ends of the tube are sealed when the tube is rolled up by a winding roll to obtain a germless inflation tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a bag-in-box (Bag
in Box), especially raw milk, milk, processed milk, etc.
The present invention relates to a bag for a bag-in-box bag for beverages, which is suitably used for transportation and storage of liquids such as minerals and beverages such as mineral water classified by the Ordinance of Milk and the like.

[0002]

2. Description of the Related Art In recent years, a bag-in-box, which is a so-called one-way container of a disposable type, has been widely used for transporting and storing various liquids such as beverages such as mineral water and industrial chemicals.

This bag-in-box is a bag-in-bag body or container made of plastic and foldable, which is used as an interior, and a corrugated cardboard box is packaged in the interior. The internal plastic bag or container is responsible for gas barrier properties, and the exterior is responsible for the rigidity required for transportation and storage. Compared with conventional glass bottles, tin cans, etc., the bag-in-box configured in this way is labor-saving and cost-saving because it does not need to be collected, and because it is foldable, it is easy to transport and store empty containers. This has the advantage that distribution costs can be reduced.

On the other hand, as a container for liquids classified as "milk" according to the Ordinance of the Ministry of Milk such as raw milk, milk, processed milk, etc., a polyethylene processed paper container called a so-called milk carton has been widely used.

However, the above milk carton
Although it has excellent properties mainly as a small-sized container for household use, it has a drawback that it is not necessarily suitable in terms of capacity, strength, etc., for applications such as commercial use or transportation between factories.

Here, the bag-in-box can be considered as a large container suitable for commercial use or transportation between factories, and the conventional bag-in-box requires a container for raw milk, milk or the like. Those which fully satisfy various characteristics such as safety and strength have not been developed yet.

[0007] Therefore, the applicant of the present application has developed and has already applied for a bag body for a milk bag in box that sufficiently satisfies various characteristics such as safety and strength required for containers of raw milk, milk and the like. (Japanese Patent Application No. 5-120802 and Japanese Patent Application No. 5-222380).

This bag for dairy bag-in-box is, for example, as shown in FIG.
E) and low density polyethylene (LDPE) coextruded PE film (eg HDPE / LDPE or H
Two or more sheets of DPE / LDPE / HDPE, etc.) are used, and the coextruded PE film group laminate 2 is obtained by stacking the respective coextruded PE films without adhering them to each other. The two-sided seal is formed by sealing the four-sided seal portion 3 in a two-layered state. further,
In this bag for box 1 for milk, the outermost layer of the coextruded PE film group laminate 2 is an HDPE layer,
The facing layer between the coextruded PE films is an LDPE layer, and the innermost layer of the coextruded PE film group laminate 2 is LDP.
It is as an E layer.

Since the innermost layer of the bag main body and the injection pouring outlet which are in direct contact with the "milk" which is the content are formed of LDPE in the bag for dairy bag-in-box, the milk etc. Sufficient safety and strength satisfying the standard of (3) are secured, recycling is easy, and heat sealability is secured.

The outermost layer of the bag body is formed of an HDPE layer. The HDPE layer is excellent in heat resistance and mechanical strength, is not affected by heat at the time of heat sealing, and is difficult to stretch and has holes. Since it is difficult to obtain, an excellent bag for dairy bag-in-box can be obtained.

Further, since the coextruded PE films are superposed on each other without adhering and the facing layers between the coextruded PE films are respectively LDPE layers, the slip between the coextruded films is good, In terms of distribution, a preferable buffering effect is exhibited.

[0012]

However, in the bag body for dairy bag-in-box described above, it is necessary to sterilize the innermost surface of the innermost layer film with γ-ray irradiation, UV irradiation, hydrogen peroxide, etc. However, there is a problem that the manufacturing cost is high.

The present invention has been made under such circumstances, and an object of the present invention is to provide an aseptic bag-in-box bag for beverages, which can be manufactured extremely easily and at a low manufacturing cost.

[0014]

In order to achieve the above object, a bag body for a sterile bag-in-box for beverages of the present invention comprises a bag body made of polyethylene (PE) film and an injection spout attached to the bag body. A bag body for a bag-in-box, the bag body comprising two or more P containing at least one coextruded PE film of high density polyethylene (HDPE) and low density polyethylene (LDPE).
It is composed of a PE film group laminate obtained by stacking E films without adhering each PE film, and the bag body is formed by sealing four sides in a state where the two PE film group laminates above and below are stacked. Is being done,
LD in which the injection spout is heat-sealed to the inner surface of the bag body.
PE spout and HDPE attached to the spout
In the bag body for beverage bag-in-box consisting of cap made of, as the upper and lower two innermost layer films, the molten resin is extruded into a tube shape from the circular die attached to the tip of the extruder and at the same time sterile air is put into the tube. Is blown to inflate the tube, and a sterile inflation tube obtained by sealing the tip and the end of the tube when the tube is wound by a winding roll is used.

Further, the bag for a sterile bag in box for beverages of the present invention has a structure in which, in the bag for a sterile bag for in box for beverages, the sterile inflation tube is a sterile inflation tube made of LDPE. is there.

[0016] Furthermore, the bag body for a sterile bag-in-box for beverages of the present invention is, if necessary, in the bag body for a sterile bag-in-boxes for beverages, wherein the sterile inflation tube is HDPE having an LDPE layer as the innermost layer. LD
It is configured as a sterile coextrusion inflation tube with PE.

Further, the bag body for a sterile bag-in-box for beverages of the present invention is, if necessary, the bag body for a sterile bag-in-box for beverages, wherein the outermost layer of the bag body is the HDPE layer of the coextruded PE film. Alternatively, the structure is formed by the LDPE layer.

[0018] Furthermore, the bag body for a sterile bag-in-box for beverages of the present invention is, if necessary, the bag body for a sterile bag-in-box for beverages, wherein the bag body is a plurality of coextruded PEs made of HDPE and LDPE. It consists of a coextruded PE film group laminate obtained by stacking films without adhering each coextruded PE film, and the bag body is a four-way seal in a state where two coextruded PE film group laminates are stacked. Are formed together with each co-extrusion P
The facing layers between the E films are LDPE layers.

The sterile bag-in-box bag for beverages of the present invention has a structure in which the inside of the four-sided seal portion is further overlapped by a four-sided seal in the bag for sterile bag-in-boxes for beverages. .

[0020]

In the present invention, the sterile inflation tube obtained by blowing sterile air into the tube to inflate it in the inflation method and sealing the tip and the end of the tube is used as the innermost layer of the bag-in-box bag. Since it is configured to be used as a film, it is not necessary to sterilize the innermost surface of the innermost layer film of the bag-in-box bag body with γ-ray irradiation, UV irradiation, hydrogen peroxide, etc. Therefore, aseptic bag-in-box for beverage The bag body can be manufactured extremely easily, and the manufacturing cost thereof is low.

[0021]

EXAMPLES Examples of the present invention will now be described to more specifically describe the present invention. FIG. 1 is a partial cross-sectional view showing an embodiment of a PE film group laminate which constitutes the bag body for a sterile bag-in-box for beverages of the present invention.

As shown in FIG. 1, the bag 1 for bag-in-box for beverage according to the present embodiment comprises a plurality of PE films 11,
Two upper and lower PE film group laminates 2 composed of 12 and 13
It is formed by sealing four sides in a state where a and 2b are overlapped with each other, and is further provided with an injection spout (not shown).

Here, the upper PE film group laminate 2a
Are three co-extruded PE films 11, 12, and 13 formed by co-extruding high-density polyethylene (HDPE) and low-density polyethylene (LDPE), and co-extruded PE film 11 / co-extruded PE film 12 from the outside. / Coextrusion P
The E films 13 are formed in this order by simply stacking the films without adhering to each other. Similarly lower PE
The film group laminate 2b is made of HDPE and LDPE
Three coextruded PE films 11,1 obtained by coextruding
Nos. 2 and 13 are formed in this order from the outside in the order of coextruded PE film 11 / coextruded PE film 12 / coextruded PE film 13 without simply adhering each film.

In the present invention, high density polyethylene (H
DPE) means polyethylene having a density of 0.94 or more, and low density polyethylene (LDPE) has a density of 0.9.
A polyethylene of less than 4. In addition, these high density polyethylene (HDPE) and low density polyethylene (L
It is necessary that all DPEs meet the following criteria for dissolution tests for heavy metals, evaporation residues and potassium permanganate consumption.

That is, dissolution test (60 ° C., 30 minutes)
Medium, 1ppm or less for heavy metals (leaching solution 4% acetic acid), 15p for evaporation residue (leaching solution 4% acetic acid)
pm or less, potassium permanganate consumption (leaching solution water)
Is 5 ppm.

With respect to burst strength and pinhole, it is not required to meet certain standards by special application under the Ordinance of the Ministry of Milk and the like. However, regarding the burst strength, when the "milk" which is the content of the bag body 1 formed by using these polyethylene is a low temperature distribution product, it is 5 kgf / cm ²
As described above, in the case of a product that is distributed at room temperature, it is preferably 8 kgf / cm ² or more. For pinholes,
Preferably there are no pinholes.

Coextrusion PE film 11 forming the outermost layer
Has a two-layer structure of an HDPE layer 11a and an LDPE layer 11b, and the thickness of the HDPE layer 11a is usually 30 μm to
It is 50 μm. The thickness of the LDPE layer 11b is usually 70 μm to 120 μm. In this embodiment, H
The DPE layer 11a has a thickness of 30 μm, and the LDPE layer 1
The thickness of 1b is 100 μm.

The coextruded PE film 11 constituting this outermost layer is overlaid with the coextruded PE film 12 adjacent thereto. The coextruded PE film 12 constituting the middle layer is composed of the LDPE layer 12a, the HDPE layer 12b and the LDP.
It has a three-layer structure including the E layer 12c.

Here, the LDPE layers 12a and 12c and the HDPE layer 12b are usually 20 to 4 in thickness.
It is 0 μm. In this embodiment, the thickness of each layer is 2
It is set to 0 μm.

Coextruded PE film 1 constituting this middle layer
A coextruded PE film 13 is superposed on the No. 3 adjacent thereto. The layer structure and the thickness of each layer of the coextruded PE film 13 forming the innermost layer are the same as those of the coextruded P film 13.
It is similar to the E film 12.

From the above, the layer structure of the bag body 1 is [HDPE layer 11a / LDPE layer 11 from the outside to the inside.
b] / [LDPE layer 12a / HDPE layer 12b / LDP
E layer 12c] / [LDPE layer 13a / HDPE layer 13b
/ LDPE layer 13c], the outermost layer is formed of HDPE, and the innermost layer is formed of LDPE.

Here, the outermost layer is formed of HDPE because HDPE has excellent heat resistance and mechanical strength as compared with LDPE, is not affected by heat at the time of heat-sealing, and is difficult to stretch and puncture. The reason for forming the innermost layer by LDPE is to ensure heat sealability.

Further, each coextruded PE film 11, 12,
13 is a four-sided seal and is laminated, and the entire surfaces of the coextruded PE films are not laminated together. Therefore, slippage occurs between the layers facing each other between the coextruded PE films, but all layers facing each other between the coextruded PE films are LDPE.
Since it is a layer, it has good slipperiness and exhibits a favorable cushioning effect in terms of distribution.

In the bag body 1 having such a structure, as in the conventional bag body for dairy bag-in-box shown in FIG.
An injection spout 4 including a spout 21 made of PE and a cap 22 made of HDPE is attached.

Specifically, the LDPE layer 13c forming the innermost layer of the bag body 1 and the LDPE spout 21 are heat-sealed, and the screw cap 22 is attached to the spout 21. The spout 21 is attached to a spout hole (not shown) provided in the bag body 1.

When the spout 21 and the cap 22 are attached to the bag body 1, it is necessary to take care so that bacteria cannot enter the inside of the bag. Regarding the sealing strength of the bag formed in this way, it is necessary that there be no damage or air leakage.

As shown in FIG. 2, the aseptic bag-in-box bag 1 for beverages of the present invention has two upper and lower innermost layer films 13 and 2 in the two upper and lower PE film group laminates 2a and 2b. As 13, the molten resin is extruded into a tube shape from a circular die attached to the tip of the extruder, at the same time aseptic air is blown into the tube to inflate it, and when the tube is wound by a winding roll, It is characterized by using a sterile inflation tube obtained by sealing the last part.

Here, a method for manufacturing the above-mentioned sterile inflation tube used in the present invention will be described. Figure 3
FIG. 3 is a schematic view showing an example of a method for producing a sterile inflation tube according to the present invention.

As shown in FIG. 3, in the method for producing a sterile inflation tube, first, the molten and kneaded molten resin is extruded into a tube shape from the slit 102 of the circular die 101 attached to the tip of the extruder 100. At this time, the temperature of the molten resin 120 extruded in a tube shape is about 200 to 300 ° C. Therefore, the molten resin 120 extruded in a tube shape is in a sterile state.

Here, the tubular film is called an inflation film. Die 101
The molten resin kneaded by heating inside is adjusted inside the die 101 so as to have a uniform and even resin distribution before extruding the molten resin from the die lip. The thickness is adjusted by moving the outer die ring to change the die opening, changing the molten resin extrusion rate, changing the tube take-up speed, and changing the blown air pressure. Be seen. The ratio of the diameter of the tube to the diameter of the die is called the blow-up ratio and is a factor in determining the thickness. Further, by rotating the die, it is possible to prevent a gauge band from being generated in a part of the wound roll.

Examples of the molten resin include polyethylene (high density and low density), polypropylene, polyvinyl chloride, polyvinylidene chloride, nylon, ionomer, polybutadiene and the like.

At the same time as the molten resin is pressed into a tube shape as described above, the sterile air 103 is compressed from the lower part 104 of the die and blown into the tube 121 to blow the tube 12.
Inflate 1. Here, the sterile air 103 is obtained by a method such as removing bacteria with a filter or the like. Aseptic air 103 blown into this tube 121
May be cooled and blown into the tube 121 to enhance the cooling efficiency of the tube 121.

Molten resin 120 extruded in a tubular shape
Is cooled while adjusting the fluidity of the material by applying cold air 106 from the hole of the cooling ring 105 to the outer circumference of the tube 121. In this case, it is preferable that the cold air 106 is strongly blown along the tube 121 at a high speed.

Next, the tube 121 is squeezed by the stabilizer 107, sandwiched between the pinch rolls 108 made of a combination of iron and rubber rolls, and pulled up. The extruded tube 1
21 is expanded and cooled between die 101 and pinch roll 108.

Next, the tip of the tube 121 is sealed by the sealing means 109, and the tube 121 is wound by the winding roll 110. Specific examples of the sealing means for sealing the tip portion of the tube 121 include a heat sealing means. This tube 121
By sealing the tip of the tube, it is possible to prevent invasion of various bacteria and the like from the tip of the tube 121 in the process of manufacturing the inflation tube. The wound tube 12
Tube 12 so that 1 does not cause blocking phenomenon
It is necessary that 1 is sufficiently cooled to reach the take-up roll.

Finally, the last portion of the tube 121 is sealed by the sealing means 109 to obtain a sterile inflation tube in which the inner surface of the tube 121 is sterilized. The sealing of the rearmost portion of the tube 121 is performed by the same method and means as the sealing of the distal end portion.

In the above-described method for producing a sterile inflation tube, a co-extruder is used as an extruder, and two or more kinds of molten resins are extruded into a tube shape from a circular die attached to the tip of the co-extruder. To produce a sterile coextrusion inflation tube. In this case, as the co-extrusion inflation tube, a co-extrusion inflation tube made of high density polyethylene (HDPE) and low density polyethylene (LDPE) (for example, HDPE / LDPE (inner surface layer) or HDPE / LDPE / HDPE (inner surface layer), etc.) ) Etc. are illustrated.

Further, in the above-described method for producing a sterile inflation tube, the tip tube and the last seal section of the inflation tube may be sealed at appropriate intervals. In this way, by sealing the space between the front and rear seal portions at an appropriate interval, even if a part of the inflation tube is pierced, aseptic conditions other than the pierced part are maintained.

Since the above-mentioned bag 1 for aseptic bag-in-box for beverages of the present invention has a structure in which a sterile inflation tube is used as the innermost layer film of the bag-for-bag for bag-in-box, There is no need to sterilize the innermost surfaces 14, 14 of the inner layer films 13, 13 with γ-ray irradiation, UV irradiation, hydrogen peroxide, etc. Therefore, it is extremely easy to manufacture a sterile bag-in-box bag for beverages. And the manufacturing cost thereof is low.

The aseptic bag-in-box bag 1 for beverages according to the present invention is not limited to the above-mentioned embodiment, and may be modified appropriately. For example, the PE film group laminate 2 constituting the bag body 1 is not limited to that shown in FIG. 1, and may be, for example, [HDPE layer (thickness 30 to 50 μm) / LDPE layer (thickness) in order from the outside. 70 to 12
0 μm)] + LDPE film (thickness 40 to 80 μm)
+ LDPE film (thickness 40 to 80 μm) (PE film group laminated body) triple bag, [HDPE layer (thickness 3
0-50 μm) / LDPE layer (thickness 70-120 μm
m)] + [LDPE layer (thickness 20-40 μm) / HDP
E layer (thickness 20 to 40 μm) / LDPE layer (thickness 20 to
40 μm)] (coextruded PE film group laminated body) double bag or [HDPE layer (thickness 30 to 50 μm)]
/ LDPE layer (thickness 70 to 120 μm)] + [LDPE
Layer (thickness 20 to 40 μm) / HDPE layer (thickness 20 to 4)
0 μm) / LDPE layer (thickness 20 to 40 μm)] + [L
DPE layer (thickness 20 to 40 μm) / HDPE layer (thickness 2
0-40 μm) / LDPE layer (thickness 20-40 μm)]
+ [LDPE layer (thickness 20 to 40 μm) / HDPE layer (thickness 20 to 40 μm) / LDPE) layer (thickness 20 to 4)
0 μm)] (coextruded PE film group laminate) 4
It may be a heavy bag or the like.

Further, instead of the outermost layer coextruded PE film consisting of the HDPE layer / LDPE layer in the above two to four-layer bag, the outermost layer coextrusion P consisting of the LDPE layer / HDPE layer is used.
E film may be used. Thus, when the outermost coextruded PE film is the LDPE layer / HDPE layer,
The impact strength can be improved.

Specifically, in the configuration of the embodiment shown in FIG. 1 described above, heat sealing is performed from the outermost layer side in the bag making process, and this heat sealing provides surface resistance.
PE deteriorates and the distance between the middle layer and the inner layer coextruded PE film, which is a sealant, is too long to obtain sufficient impact strength. For example, if the bag is dropped from a height of 60 cm, the bag will break. Resulting in. On the other hand, the outermost layer coextruded PE film in the above-mentioned example was used as the LDPE layer / HD
When the PE layer is used, even if the bag is dropped 5 times from a height of 90 cm, bag breakage does not occur and sufficient impact strength can be obtained.

The sterile bag-in-box bag for beverages according to the present invention is the bag-sterile bag-in-box bag for beverages in the above-mentioned embodiment, in which the inside of the four-sided sealing portion is further overlapped by a four-sided seal. Heavy seal). In this case, it is preferable that the four corners of the inner four-sided seal portion are also curvedly sealed.

This aseptic bag-in-box bag for beverages is, for example, in accordance with the ministerial ordinance of milk such as raw milk, milk and processed milk,
It is particularly suitable for use as a container for products classified as "milk", and is used in a state of being housed in an outer corrugated cardboard box.

[0055]

As described above, according to the bag body for aseptic bag-in-box for beverage of the present invention, aseptic air is blown into the tube to inflate it in the inflation method, and the tip and the end of the tube are inflated. Aseptic inflation tube obtained by sealing, since it is configured as an innermost layer film of the bag body for bag-in-box, the innermost surface of the innermost layer film of the bag body for bag-in-box, γ-ray irradiation, UV irradiation, Since it is not necessary to sterilize with hydrogen peroxide or the like, a sterile bag-in-box bag for beverages can be manufactured very easily, and the manufacturing cost thereof is low.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an example of a PE film group laminate constituting the bag body for a sterile bag-in-box for beverages of the present invention.

FIG. 2 is an exploded cross-sectional view showing a sterile bag-in-box bag for beverages of the present invention.

FIG. 3 is a schematic view showing an example of a method for manufacturing a sterile inflation tube.

FIG. 4 is a perspective view showing a conventional bag body for a bag-in-box for beverages.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Aseptic bag-in-box bag for beverage 2 ... PE film group laminated body 3 ... Four-sided seal part 4 ... Injection pouring tool 11 ... Co-extrusion PE film 11a ... High density polyethylene (HDPE) layer 11b ... Low density polyethylene (LDPE) ) Layer 12 ... Coextruded PE film 13 ... Coextruded PE film 21 ... Spout 22 ... Cap 100 ... Extruder 101 ... Die 103 ... Aseptic air 105 ... Cooling ring 106 ... Cold air 107 ... Stabilizer 108 ... Pinch roll 109 ... Sealing means 110 ... Winding roll 120 ... Molten resin extruded in a tube shape 121 ... Tube

Claims (6)

[Claims] 1. A bag-in-box bag body comprising a bag body made of a polyethylene (PE) film and an injection spout attached to the bag body, wherein the bag body is a high density polyethylene (HDPE). PE obtained by stacking two or more PE films containing at least one co-extruded PE film of polyethylene and low density polyethylene (LDPE) without adhering between the PE films
The bag main body is made of a film group laminate, and the bag body is formed by sealing the four sides of the two PE film group laminates on top of each other, and the injection spout is heat-fused to the inner surface of the bag body. A bag bag for a beverage bag-in-box comprising an LDPE spout to be worn and an HDPE cap attached to the spout, comprising: a circular die attached to the tip of an extruder as upper and lower two innermost layer films. Aseptic inflation tube obtained by extruding molten resin into a tube at the same time as blowing sterile air into the tube to inflate it and sealing the tip and the end of the tube when winding the tube with a winding roll was used. A bag body for a sterile bag-in-box for beverages, which is characterized in that 2. A sterile inflation tube is an LD
The bag body for a sterile bag-in-box for beverage according to claim 1, which is a PE-made sterile inflation tube. 3. The sterile bag-in-box bag for beverage according to claim 1, wherein the sterile inflation tube is a sterile coextrusion inflation tube of HDPE and LDPE having an LDPE layer as an innermost layer. 4. The bag body for a sterile bag-in-box for beverages according to claim 1, wherein the outermost layer of the bag body is an HDPE layer or LDPE of the coextruded PE film.
The bag body for a sterile bag-in-box for beverages according to claim 1, wherein the bag body is formed of layers. 5. The sterile bag-in-box bag for beverages according to claim 1, wherein the bag body is HDP.
A coextruded PE film group laminate obtained by stacking a plurality of coextruded PE films composed of E and LDPE without adhering the respective coextruded PE films, and the bag body has two coextruded PE film groups. The sterile bag-in bag for beverages according to any one of claims 1 to 4, wherein the laminates are formed by sealing in four directions in a stacked state, and the facing layers between the coextruded PE films are LDPE layers. Box bag. 6. The aseptic bag-in-box bag for beverages according to claim 1, wherein the insides of the four-sided seal portions are further overlapped by four-sided seals. Bag body for bag-in-box.