EP4786366A1

EP4786366A1 - Bag-in-box and method of using it

Info

Publication number: EP4786366A1
Application number: EP26155194.9A
Authority: EP
Inventors: Kosei Matsuda; Takeshi Aoki; Tomoko Mita
Original assignee: Toppan Holdings Inc
Current assignee: Toppan Holdings Inc
Priority date: 2025-01-30
Filing date: 2026-01-30
Publication date: 2026-08-05

Abstract

[Problem] To provide a bag-in-box capable of easily suppressing remaining of a content.

[Solution] A bag-in-box (1) comprising: a flexible inner bag (2) forming an accommodation space (2s) for accommodating a content (10); an outer box (3) accommodating the inner bag (2); and a plug (4) having a dispensing port (33) configured to communicate with the accommodation space (2s) of the inner bag (2) and to dispense the content (10) from the accommodation space (2s); wherein the dispensing port (33) is configured to be capable of taking in outside air.

Description

TECHNICAL FIELD

The present invention relates to a bag-in-box in which a flexible inner bag is accommodated in an outer box.

BACKGROUND ART

A bag-in-box, in which a flexible inner bag is accommodated in an outer box, is widely used as a package for beverages, foods, liquid cosmetics, liquid industrial products, and the like because it is lightweight and difficult to damage.
For example, Patent Document 1 below describes a bag-in-box equipped with an inner bag in which corner portions are formed at the corners of the lower side and the side edges, wherein the corner portions are fixed to the bottom of the outer box to prevent the contents from remaining in the corners of the inner bag. Patent Document 2 below describes a beverage supply device equipped with a bag body having a rigid spout and an outer box for accommodating the bag body, wherein an air hole formed in the spout is closed with a pin.

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2004-018079
[Patent Document 2] Japanese Unexamined Utility Model Publication No. S63-013867

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

In a bag-in-box, when the content decreases due to dispensing, the inner bag contracts as the internal pressure drops, causing a part of the internal space of the inner bag to become blocked, and the content may remain inside the inner bag. Therefore, in the beverage supply device described in Patent Document 2, the blockage of the inner bag is eliminated by removing the pin to open the air hole and supplying air to the internal space of the inner bag, so that the content remaining inside the inner bag is dispensed. However, the pin had to be removed every time the content decreased, which required time and effort for the operation.
In view of this, an object of the present invention is to provide a bag-in-box and a method of using the same capable of easily suppressing the remaining of contents.

MEANS FOR SOLVING THE PROBLEMS

The aforementioned problems are solved by the bag-in-box of claim 1. The present invention further includes the following embodiments [1] to [32].

[1] A bag-in-box comprising:
- a flexible inner bag forming an accommodation space for accommodating a content;
- an outer box accommodating the inner bag; and
- a plug having a dispensing port configured to communicate with the accommodation space of the inner bag and to dispense the content from the accommodation space;
- wherein the dispensing port is configured to be capable of taking in outside air.
[2] The bag-in-box according to [1], wherein the dispensing port has a diameter capable of taking in outside air.
[3] The bag-in-box according to [2], wherein the diameter of the dispensing port is 10 mm or more and 30 mm or less.
[4] The bag-in-box according to [2] or [3], wherein the diameter of the dispensing port is 12 mm or more and 28 mm or less.
[5] The bag-in-box according to any one of [1] to [4], wherein the inner bag comprises a spout member having a discharge opening for discharging the content, and the plug comprises a ventilation pipe configured to communicate with the dispensing port and to be inserted into the accommodation space of the inner bag through the discharge opening of the spout member, and a connecting portion configured to connect with the discharge opening of the spout member.
[6] The bag-in-box according to [5], wherein the connecting portion of the plug includes a nut member configured to connect with the discharge opening of the spout member.
[7] The bag-in-box according to [6], wherein the nut member is formed by assembling a plurality of parts divided along a radial direction.
[8] The bag-in-box according to [5], wherein the connecting portion of the plug has a plug-in type connection structure in which the plug is connected to the discharge opening by being fitted into the discharge opening by being pushed into the discharge opening of the spout member in an axial direction.
[9] The bag-in-box according to [5], wherein the connecting portion of the plug has a flange-type connection structure in which a flange portion formed on the plug and a flange portion formed on the spout member are connected to each other by locking, welding, or fitting.
[10] The bag-in-box according to any one of [5] to [9], wherein the ventilation pipe of the plug has a ventilation portion for supplying outside air taken in from the dispensing port to the accommodation space of the inner bag.
[11] The bag-in-box according to [10], wherein the ventilation portion is a plurality of ventilation holes opening toward the accommodation space of the inner bag.
[12] The bag-in-box according to [11], wherein the ventilation pipe of the plug extends along an axial direction, and the ventilation holes open toward a direction intersecting the axial direction.
[13] The bag-in-box according to [11], wherein the ventilation pipe of the plug extends along an axial direction, and the ventilation holes are slits having an axis parallel to the axial direction.
[14] The bag-in-box according to [10], wherein the ventilation portion is a mesh portion provided in the ventilation pipe.
[15] The bag-in-box according to any one of [10] to [14], wherein the plug further comprises a cock having the dispensing port, and an extension nozzle provided between the ventilation pipe and the cock and configured to cause the ventilation portion and the dispensing port to communicate with each other, wherein at least a part of the extension nozzle extends in a direction inclined with respect to the axial direction.
[16] The bag-in-box according to [15], wherein the cock of the plug is detachably attached to an end of the extension nozzle of the plug.
[17] The bag-in-box according to [15], wherein the ventilation pipe and the extension nozzle of the plug are integrally formed.
[18] The bag-in-box according to [15], wherein the connecting portion of the plug is a nut member having an engagement hook capable of engaging with a flange portion formed on the extension nozzle of the plug, and fastening the extension nozzle and the spout member by engagement between the flange portion and the engagement hook accompanying thread engagement with a male thread portion formed on the spout member of the inner bag.
[19] The bag-in-box according to [15], wherein a seal member for sealing between the discharge opening of the spout member of the inner bag and the extension nozzle of the plug is provided.
[20] The bag-in-box according to [15], wherein a guide ring for guiding the discharge opening of the spout member of the inner bag to the flange portion of the extension nozzle of the plug is formed on the extension nozzle.
[21] The bag-in-box according to [20], wherein the guide ring of the extension nozzle of the plug is formed in a tapered shape in which the outer diameter becomes smaller toward the ventilation pipe side than toward the cock side.
[22] The bag-in-box according to any one of [1] to [21], wherein the dispensing port of the plug has a larger diameter than the discharge opening of the spout member of the inner bag.
[23] The bag-in-box according to any one of [1] to [22], wherein the outer box has a bottom surface, a top surface, and side surfaces, the bottom surface has a smaller area than the side surfaces, and the plug is taken out to the outside of the outer box through an opening formed in the bottom surface.
[24] The bag-in-box according to [23], wherein the outer box has a rectangular parallelepiped shape having four side surfaces, and the bottom surface has an area smaller than the area of each of the four side surfaces.
[25] The bag-in-box according to [23] or [24], wherein the opening through which the plug is taken out is arranged at an end of the bottom surface.
[26] The bag-in-box according to any one of [1] to [25], wherein the inner bag has no opening other than the dispensing port.
[27] The bag-in-box according to any one of [1] to [26], wherein the inner bag has an accommodating portion forming the accommodation space, and the accommodating portion is composed of a flexible film.
[28] The bag-in-box according to [27], wherein the rigidity (loop stiffness) of the film is 30 mN or more and 300 mN or less, and more preferably 65 mN or more and 88 mN or less.
[29] The bag-in-box according to [27], wherein the film is composed of:
- polyethylene layer / adhesive layer / polyethylene layer // polyethylene layer / adhesive layer / polyethylene layer, or
- polyethylene layer / adhesive layer / nylon 6 / EVOH / nylon 6 / adhesive layer / polyethylene layer
(Here, "/" means that adjacent layers are laminated, and "//" means that they are welded by heat sealing. In addition, it is preferable to use a non-oriented polyethylene film as the polyethylene layer).
[30] A method of using the bag-in-box according to any one of [1] to [29], comprising an intake step of performing dispensing of the content from the inner bag via the dispensing port and performing intake of outside air into the inner bag via the dispensing port.
[31] The method according to [30], comprising, before the intake step, a starting step of starting the dispensing of the content in the inner bag and performing only the dispensing of the content from the inner bag via the dispensing port.
[32] The method according to [30] or [31], comprising, after the intake step, a stopping step of stopping the dispensing of the content from the inner bag via the dispensing port and stopping the intake of outside air into the inner bag (2) via the dispensing port.

EFFECTS OF THE INVENTION

According to the bag-in-box relating to the present invention, the remaining of contents can be easily suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS

[FIG. 1] is a cross-sectional view showing an overall schematic configuration of a first embodiment of a bag-in-box relating to the present invention.
[FIG. 2] is a perspective view showing the appearance of a plug of the bag-in-box of FIG. 1.
[FIG. 3] is a side view showing a schematic configuration of the plug of FIG. 2.
[FIG. 4A] is an explanatory view schematically showing a region where content flows to a dispensing port of a plug when the liquid level height of the content is higher than a reference height.
[FIG. 4B] is an explanatory view schematically showing a region where content flows to a dispensing port of a plug when the liquid level height of the content is lower than a reference height.
[FIG. 5] is a cross-sectional view schematically showing an internal state when the content of the bag-in-box of FIG. 1 is being dispensed.
[FIG. 6] is a side view showing a schematic configuration of a modification of the plug of FIGS. 2 and 3.
[FIG. 7A] is a partially extracted appearance view showing a schematic configuration of a modification of a ventilation pipe of the plug of FIGS. 2 and 3.
[FIG. 7B] is a partially extracted appearance view showing a schematic configuration of another modification of a ventilation pipe of the plug of FIGS. 2 and 3.
[FIG. 8] is an external plan view showing a schematic configuration of a modification of an inner bag of the bag-in-box of FIG. 1.
[FIG. 9] is a perspective view showing a schematic configuration of a main part of a second embodiment of a bag-in-box relating to the present invention.
[FIG. 10] is a cross-sectional view showing a schematic configuration of the plug of FIG. 9.
[FIG. 11] is a perspective view showing a schematic configuration of a main part of a third embodiment of a bag-in-box relating to the present invention.
[FIG. 12] is a cross-sectional view showing a schematic configuration of the plug of FIG. 11.
[FIG. 13] is an exploded perspective view showing a schematic configuration of a nut member of FIGS. 11 and 12.

MODE FOR CARRYING OUT THE INVENTION

Embodiments of a bag-in-box relating to the present invention will be described based on the drawings. Note that the present invention is not limited only to the following embodiments described based on the drawings, and various technical matters described in each embodiment can be appropriately combined or replaced as necessary.

[First Embodiment]

A first embodiment of a bag-in-box relating to the present invention will be described based on FIGS. 1 to 5.
As shown in FIG. 1, a bag-in-box 1 relating to this embodiment is a package for accommodating a liquid content 10, and is configured such that the content 10 can be dispensed in a required amount. The bag-in-box 1 is installed, for example, in a storefront for selling the content 10 by weight.
The bag-in-box 1 comprises an inner bag 2 for accommodating the content 10, an outer box 3 for accommodating the inner bag 2, and a plug 4 for dispensing the content 10. The inner bag 2 is a flexible bag body and accommodates the content 10. Examples of the content 10 include beverages such as fruit juice drinks, juices, carbonated drinks, tea, coffee, milk drinks, and soups; cleaning agents such as shampoos, rinses, dishwashing detergents, and laundry detergents; and liquid industrial products such as oils, disinfectant solutions, liquid fertilizers, bactericides, and insecticides.
The inner bag 2 is a large-capacity bag body and has a volume of, for example, 3 liters or more and 20 liters or less. The inner bag 2 has an accommodating portion 11 forming an accommodation space 2s, and a discharge opening 12 for discharging the content 10 from the accommodation space 2s. The content 10 is filled into the accommodation space 2s of the inner bag 2. The accommodating portion 11 is composed of a flexible plastic film.
The plastic film constituting the accommodating portion 11 is selected in consideration of conditions such as the type, capacity, and storage period of the content 10. Typically, the accommodating portion 11 is composed of a polyolefin-based film such as polyethylene or polypropylene. The accommodating portion 11 is preferably a plastic film having water resistance, chemical resistance, gas barrier properties, etc., in order to suppress deterioration while maintaining the quality of the content 10. Note that the accommodating portion 11 can also be a laminate in which a plurality of types of plastic films are overlapped. In order to smooth the dispensing of the content 10 via the dispensing port 33 and the intake of outside air in an intake step described later, it is preferable that the rigidity of the film forming the accommodating portion 11 is within a certain range. More specifically, the loop stiffness (rigidity) of the film forming the accommodating portion 11 is preferably 30 mN or more and 300 mN or less, and more preferably 65 mN or more and 88 mN or less. If the rigidity of the film is less than 30 mN, there is a disadvantage that the film is too soft and the accommodating portion tends to contract. On the other hand, if the rigidity of the film exceeds 300 mN, there is a disadvantage that wrinkles or cracks are likely to occur in the film due to a slight load because the film is difficult to bend. The loop stiffness can be measured by the following procedure. A test piece having a width of 15 mm and a length of 200 mm is cut out from the film, and this is used as a measurement sample. Both ends of the measurement sample are clamped and fixed with clips so that the sealant layer (content side) of the measurement sample is on the inside, forming a circular loop with a loop length of 50 mm. The obtained circular loop is pushed from the opposite side of the clips at a pushing speed of 3.3 mm/sec, and the load (repulsion force) required for the pushing length to reach 10 mm is defined as the loop stiffness value (stiffness strength). As a measuring device, a loop stiffness tester (manufactured by Toyo Seiki Seisaku-sho, Ltd.) can be exemplified. In addition, as the layer configuration of the film forming the accommodating portion 11, the following can be exemplified:

polyethylene layer / adhesive layer / polyethylene layer // polyethylene layer / adhesive layer / polyethylene layer
polyethylene layer / adhesive layer / nylon 6 / EVOH / nylon 6 / adhesive layer / polyethylene layer

Among these, when the film forming the accommodating portion 11 is a polyethylene layer / adhesive layer / polyethylene layer // polyethylene layer / adhesive layer / polyethylene layer, it has appropriate rigidity, so that the dispensing of the content 10 via the dispensing port 33 and the intake of outside air become smooth in the intake step described later.
The discharge opening 12 is an opening for discharging the content 10 from the inner bag 2. It is preferable that the discharge opening 12 is provided such that its center is located within a range of 40 mm to 80 mm from the peripheral edge of the inner bag 2 when the inner bag 2 is unfilled, because the remaining amount of the content 10 in the inner bag 2 can be suppressed.
The content 10 is filled into the accommodation space 2s through the discharge opening 12. Note that the inner bag 2 can be arranged in the outer box 3 after the content 10 is filled, or the content 10 can be filled after the inner bag 2 is arranged in the outer box 3. The discharge opening 12 is typically formed by a resin spout member 12a attached to the accommodating portion 11 and communicating with the accommodation space 2s (see FIG. 3).
The outer box 3 has a function of protecting the inner bag 2 from external impacts and the like during storage, transportation, and the like. The outer box 3 is composed of, for example, corrugated cardboard, cardboard, or the like. Depending on the type of content 10, the outer box 3 can also be composed of a plastic sheet, a foamed urethane material, or the like.
Typically, the outer box 3 is a rectangular parallelepiped or cubic box having a bottom surface 21, a top surface 22, and four side surfaces 23. The bottom surface 21 has a smaller area than each side surface 23. For example, the outer box 3 has a rectangular parallelepiped shape that is flat in the depth direction, with a height smaller than the width and larger than the depth.
More specifically, the outer box 3 has a height of, for example, about 250 mm to 350 mm, a width of, for example, about 350 mm to 450 mm, and a depth of, for example, about 50 mm to 150 mm. In the outer box 3, an opening 3a for exposing the discharge opening 12 of the spout member 12a of the inner bag 2 is formed in the bottom surface 21 (see FIG. 3).
The plug 4 communicates with the accommodation space 2s of the inner bag 2 and has a function of dispensing the content 10 from the inner bag 2. The plug 4 is taken out to the outside of the outer box 3 through the opening 3a formed in the bottom surface 21 of the outer box 3. The opening 3a can be formed at any position on the bottom surface 21. That is, the plug 4 is taken out from any position on the bottom surface 21. However, from the viewpoint of more efficiently suppressing the remaining of content, it is preferable that the opening 3a through which the plug 4 is taken out is arranged at an end of the bottom surface 21 instead of the center.
The plug 4 has a cylindrical main body portion 30. The main body portion 30 has a proximal end portion 31 and a distal end portion 32, and extends along an axis Z between the proximal end portion 31 and the distal end portion 32. In the following description, in the direction along the axis Z (hereinafter referred to as "axial direction"), the direction from the proximal end portion 31 toward the distal end portion 32 is sometimes referred to as "downward," and the direction from the distal end portion 32 toward the proximal end portion 31 is sometimes referred to as "upward." Inside the main body portion 30, a dispensing passage 30p extending in the axial direction between the proximal end portion 31 and the distal end portion 32 is formed.
As shown in FIG. 3, the proximal end portion 31 has a substantially cylindrical shape and is fittable into the discharge opening 12 of the spout member 12a of the inner bag 2. It is preferable that the proximal end portion 31 is formed with a retaining ring for preventing detachment when fitted into the discharge opening 12. The distal end portion 32 is arranged on the opposite side of the proximal end portion 31 and has a dispensing port 33 for dispensing the content 10 from the inner bag 2.
When the proximal end portion 31 is fitted into the discharge opening 12 of the spout member 12a of the inner bag 2, the dispensing port 33 is brought into communication with the accommodation space 2s of the inner bag 2 via the dispensing passage 30p. As a result, the content 10 accommodated in the accommodation space 2s is dispensed from the dispensing port 33. It is preferable that the distal end portion 32 is arranged lower than the proximal end portion 31 so that the content 10 can be dispensed by the self-weight (potential energy) of the content 10.
The plug 4 further comprises a ventilation pipe 34 extending in the axial direction from the main body portion 30. The ventilation pipe 34 is, for example, a hollow cylindrical body having a length of about 50 mm to 70 mm and an outer diameter of about 30 mm. The ventilation pipe 34 is made of, for example, resin and is formed integrally with the main body portion 30.
The ventilation pipe 34 communicates with the dispensing port 33 via the dispensing passage 30p and projects upward from the proximal end portion 31. As shown in FIGS. 1 and 3, when the proximal end portion 31 is fitted into the discharge opening 12 of the spout member 12a of the inner bag 2, the ventilation pipe 34 is inserted into the accommodation space 2s of the inner bag 2 through the discharge opening 12.
At the upper end of the ventilation pipe 34, an opening 35 for guiding the content 10 in the inner bag 2 to the dispensing passage 30p is formed. Further, the ventilation pipe 34 has a plurality of ventilation holes 36 opening toward the accommodation space 2s of the inner bag 2. Typically, the plurality of ventilation holes 36 each open so as to penetrate the side wall of the ventilation pipe 34 in a direction intersecting (perpendicular to) the axis Z, and cause the accommodation space 2s and the dispensing passage 30p to communicate with each other. In the present embodiment, the shape of the opening of the ventilation holes 36 is round, but the shape of the opening of the ventilation holes is not limited thereto and may be, for example, a slit shape having an axis parallel to the axis Z. Instead of the ventilation holes 36, it is also possible to provide a mesh portion capable of ventilation in the ventilation pipe. In this case, the ventilation pipe itself may be formed of a mesh.
The plurality of ventilation holes 36 are, for example, circular through holes each having a diameter of 3 mm to 5 mm. The plurality of ventilation holes 36 have functions of respectively guiding the content 10 in the inner bag 2 to the dispensing passage 30p and respectively supplying outside air taken in from the dispensing port 33 to the accommodation space 2s.
The plug 4 further comprises a dispensing valve 37. The dispensing valve 37 is provided in the dispensing passage 30p between the proximal end portion 31 and the distal end portion 32, and is configured to switch between supplying and stopping the supply of the content 10. The dispensing valve 37 is configured to be switched between opening and closing by operating, for example, a handle 38 arranged on the side of the main body portion 30.
That is, when the proximal end portion 31 is fitted into the discharge opening 12 of the spout member 12a of the inner bag 2 and the dispensing valve 37 is opened, the dispensing port 33 communicates with the accommodation space 2s of the inner bag 2 via the dispensing passage 30p, and the content 10 in the accommodation space 2s is dispensed from the dispensing port 33 through the dispensing passage 30p. On the other hand, when the dispensing valve 37 is closed, communication between the accommodation space 2s and the dispensing port 33 is shut off, and the dispensing of the content 10 is stopped.
The dispensing port 33 of the plug 4 is configured to be capable of taking in outside air. More preferably, the dispensing port 33 of the plug 4 is configured to be capable of taking in outside air while dispensing the content 10. In the present embodiment, the intake of outside air via the dispensing port 33 is enabled by providing the ventilation pipe 34 or by making the diameter of the dispensing port 33 a diameter capable of taking in air. The diameter of the dispensing port 33 capable of taking in air is, for example, 10 mm or more and 30 mm or less. In order to make the dispensing of the content 10 and the intake of outside air smoother, the diameter of the dispensing port 33 is preferably 12 mm or more and 28 mm or less, and more preferably 15 mm or more and 25 mm or less. Note that when the dispensing port 33 is circular, the inner diameter of the dispensing port 33 is defined as the diameter of the dispensing port 33. When the dispensing port 33 is a regular polygonal shape, the diameter of a circle inscribed in the regular polygonal dispensing port 33 is defined as the diameter of the dispensing port 33.
Next, a method of using the bag-in-box 1 will be described.
The method of using the bag-in-box 1 includes an intake step of performing dispensing of the content 10 from the inner bag 2 via the dispensing port 33 and performing intake of outside air into the inner bag 2 via the dispensing port 33. The method of using the bag-in-box 1 may further include, before the intake step, a starting step of starting the dispensing of the content 10 in the inner bag 2 and performing only the dispensing of the content from the inner bag 2 via the dispensing port 33. That is, the dispensing port 33 of the plug 4 does not take in outside air during dispensing (starting step) when the liquid level height of the content 10 in the accommodation space 2s is higher than a reference height, and takes in outside air during dispensing (intake step) when the liquid level height of the content 10 in the accommodation space 2s is lower than the reference height. The method of using the bag-in-box 1 may further include, after the intake step, a stopping step of stopping the dispensing of the content 10 from the inner bag 2 via the dispensing port 33 and stopping the intake of outside air into the inner bag 2 via the dispensing port 33.
Note that the liquid level height is the height of the liquid surface of the content 10 based on the bottom surface 21. The actual diameter of the dispensing port 33 is designed according to the density, specific gravity, viscosity, etc. of the content 10. Also, the reference height is, for example, 10%, 20%, 30%, 40%, or 50% of the height of the outer box 3 based on the bottom surface 21. For example, when the reference height is to be increased, the diameter of the dispensing port 33 can be designed larger, and when the reference height is to be decreased, the diameter of the dispensing port 33 can be designed smaller.
The pressure applied to the discharge opening 12 is proportional to the liquid level height of the content 10 in the accommodation space 2s. For example, when the liquid level height of the content 10 is high, the pressure applied to the discharge opening 12 increases, and the flow rate of the content 10 dispensed from the dispensing port 33 also increases. On the other hand, when the liquid level height of the content 10 is low, the pressure applied to the discharge opening 12 decreases, and the flow rate of the content 10 dispensed from the dispensing port 33 also decreases.
In FIGS. 4A and 4B, the hatched portion shows the region where the content 10 flows. When the liquid level height of the content 10 is higher than the reference height, the flow rate of the content 10 dispensed from the dispensing port 33 increases, so the cross-sectional area of the content 10 (the region where the content 10 flows in the dispensing port 33) becomes large. Therefore, as shown in FIG. 4A, the cross-sectional area of the content 10 substantially coincides with the area of the dispensing port 33. In this case, since the dispensing port 33 is blocked by the content 10 during dispensing, outside air is not taken in from the dispensing port 33 (starting step). As a result, the internal pressure of the accommodation space 2s decreases with the dispensing of the content 10, and the inner bag 2 contracts.
On the other hand, when the liquid level height of the content 10 is lower than the reference height, the flow rate of the content 10 dispensed from the dispensing port 33 decreases, so the cross-sectional area of the content 10 becomes small. Therefore, as shown in FIG. 4B, the cross-sectional area of the content 10 becomes smaller than the area of the dispensing port 33. In this case, a region 40 not blocked by the content 10 is formed in the dispensing port 33 during dispensing. As a result, outside air (air) 42 is taken in from the dispensing port 33 through the region 40 due to the pressure difference between the internal pressure of the accommodation space 2s and atmospheric pressure. That is, the dispensing of the content 10 from the dispensing port 33 and the intake of outside air 42 are performed simultaneously (intake step).
Thereby, as shown in FIG. 5, when outside air 42 is taken in from the dispensing port 33, the outside air 42 flows into the ventilation pipe 34 through the dispensing passage 30p and is supplied to the accommodation space 2s through the plurality of ventilation holes 36 of the ventilation pipe 34. When outside air 42 is supplied to the accommodation space 2s, the contraction of the inner bag 2 is suppressed.
As described above, in the bag-in-box 1, when the liquid level height of the content 10 in the inner bag 2 is higher than the reference height, outside air 42 is not taken in from the dispensing port 33 during dispensing, so that quality deterioration of the content 10 due to early supply of outside air 42 to the inner bag 2 can be prevented.
On the other hand, when the liquid level height of the content 10 in the inner bag 2 is lower than the reference height, outside air 42 is taken in from the dispensing port 33 during dispensing and supplied to the accommodation space 2s of the inner bag 2. As a result, it is possible to suppress the inner surfaces of the inner bag 2 from closely adhering to each other and blocking the accommodation space 2s, and it is possible to suppress the remaining of the content 10 (liquid residue) in the inner bag 2. Therefore, the content 10 can be dispensed from the inner bag 2 to the end. When the content 10 is dispensed from the inner bag 2 to the end, the dispensing of the content 10 from the inner bag 2 via the dispensing port 33 and the intake of outside air into the inner bag 2 via the dispensing port 33 stop (stopping step).
In addition, the inner bag 2 has no opening other than the dispensing port 33. In this bag-in-box 1, since outside air 42 is taken in when the liquid level height of the content 10 becomes lower than the reference height, an operation such as removing a pin to open an air hole becomes unnecessary, and the user's effort can be reduced.
Also, in this bag-in-box 1, since the plug 4 is arranged on the bottom surface 21 of the outer box 3 having a small area, the content 10 can be dispensed by the potential energy of the content 10 without using external power such as a pump.
Also, in this bag-in-box 1, since the ventilation pipe 34 is inserted into the accommodation space 2s of the inner bag 2, outside air 42 taken in from the dispensing port 33 can be supplied to the upper part of the accommodation space 2s.
Further, since a plurality of ventilation holes 36 are formed in the ventilation pipe 34, even when the accommodating portion 11 of the inner bag 2 closely adheres to the ventilation pipe 34 due to the contraction of the inner bag 2, blockage of the ventilation pipe 34 can be largely suppressed. Thereby, outside air 42 can be reliably supplied into the accommodation space 2s of the inner bag 2, and the content 10 can be stably dispensed from the inner bag 2.

As a modification of the present embodiment, for example, as shown in FIG. 6, it is also possible to have a plug 4A having a dispensing port 33 with a diameter D1 larger than the diameter D2 of the ventilation pipe 34. Also, in the plug 4A, the diameter D1 of the dispensing port 33 can be made larger than the diameter of the discharge opening 12 of the spout member 12a of the inner bag 2. Since such a plug 4A has a large diameter D1 of the dispensing port 33, it becomes easy to take in outside air 42 from the dispensing port 33 during dispensing.
Also, in the present embodiment, the case of the ventilation pipe 34 in which a plurality of ventilation holes 36 are formed has been described, but any ventilation pipe in which at least one ventilation hole 36 is formed is applicable in the same manner as in the present embodiment.
Also, for example, as shown in FIG. 7A, by cutting the cylindrical body obliquely with respect to the axis Z, it is also possible to have a ventilation pipe 34A having an opening 35A with an end face directed in a direction intersecting (inclined) with respect to the axis Z. Since this ventilation pipe 34A has a long-hole-shaped opening 35A extending in an oblique direction with respect to the axis Z, even if the accommodating portion 11 closely adheres due to contraction of the inner bag 2, blockage can be suppressed. Thereby, outside air 42 can be supplied to the accommodation space 2s while stably dispensing the content 10.
Also, for example, as shown in FIG. 7B, it is also possible to have a ventilation pipe 34B having a slit-shaped ventilation hole 36B extending in the axial direction. In this ventilation pipe 34B, the ventilation hole 36B facing in a direction perpendicular to the axis Z opens inside the accommodation space 2s of the inner bag 2. Since the ventilation hole 36B of this ventilation pipe 34B extends in a slit shape, even if the accommodating portion 11 closely adheres due to contraction of the inner bag 2, blockage can be suppressed. Thereby, outside air 42 can be supplied to the accommodation space 2s while stably dispensing the content 10.
Also, in the present embodiment, the plug 4 is taken out to the outside of the outer box 3 through the opening 3a formed in the bottom surface 21, but the present invention is not limited thereto. As a modification, for example, the plug 4 can also be taken out to the outside of the outer box 3 through an opening formed in the lower part of the side surface 23. Even in this case, it is possible to dispense the content 10 using the potential energy of the content 10.
Also, in the present embodiment, a straight-shaped plug 4 in which the dispensing passage 30p extends in the axial direction as shown in FIG. 3 has been described, but the present invention is not limited thereto. As a modification, for example, an L-shaped plug is also possible. Also, the plug 4 may be configured to supply outside air 42 taken in from the dispensing port 33 from the proximal end portion 31 of the main body portion 30 to the accommodation space 2s without comprising the ventilation pipe 34. Further, the outer box 3 is not limited to a rectangular parallelepiped or cubic shape and may have, for example, a cylindrical shape.
Also, for example, when the inner bag 2 is unfilled, as shown in FIG. 8, it is preferable to form a heat seal (shoulder seal) 2c connecting the sides 2b constituting the corner portion 2a so as to form a triangular portion 2d including the corner portion 2a of the square-shaped inner bag 2. Thereby, when the inner bag 2 is filled with the content 10, it is possible to prevent the content 10 from entering into the triangular portion 2d including the corner portion 2a where the content 10 tends to remain, and the remaining amount of the content 10 in the inner bag 2 can be suppressed when the dispensing of the content 10 from the inner bag 2 is finished. In particular, it is very preferable that the length L of each side 2b of the triangular portion 2d constituting the corner portion 2a of the inner bag 2 when unfilled is within the range of 40 mm to 80 mm, because the remaining amount of content 10 can be suppressed while suppressing the reduction in the fillable amount of content 10.

[Second Embodiment]

A second embodiment of a bag-in-box relating to the present invention will be described based on FIGS. 9 and 10. However, for parts similar to those in the above-described embodiment, descriptions overlapping with the descriptions in the above-described embodiment will be omitted by using the same reference numerals as those used in the description of the above-described embodiment.
The bag-in-box relating to this embodiment comprises an inner bag 2 and an outer box 3, and as shown in FIG. 9, comprises a plug 4B for dispensing content 10. That is, the bag-in-box 1B relating to this embodiment comprises a plug 4B instead of the plug 4 of the bag-in-box 1 relating to the above-described embodiment.
As shown in FIGS. 9 and 10, the plug 4B comprises a ventilation pipe 34, an extension nozzle 51, and a cock 52. The ventilation pipe 34 extends in a direction along the axis Z (axial direction) and has a plurality of ventilation holes 36 opening toward the accommodation space 2s, similarly to the above-described embodiment. When the plug 4B is connected to the discharge opening 12 of the spout member 12a of the inner bag 2, the ventilation pipe 34 is inserted into the accommodation space 2s of the inner bag 2 through the discharge opening 12.
One end of the ventilation pipe 34 is connected to one end 51a of the extension nozzle 51. The other end 51b of the extension nozzle 51 is connected to the cock 52. That is, the extension nozzle 51 is provided between the ventilation pipe 34 and the cock 52. At least a part of the extension nozzle 51 extends linearly in a direction inclined with respect to the axis Z of the ventilation pipe 34. Note that the extension nozzle 51 may be partially or entirely curved.
The extension nozzle 51 has a passage 51p for causing the plurality of ventilation holes 36 of the ventilation pipe 34 and the dispensing port 52b of the cock 52 to communicate with each other. At least a part of the passage 51p of the extension nozzle 51 extends linearly or curvedly in a direction inclined with respect to the axis Z. The passage 51p has functions of guiding the content 10 in the inner bag 2 from the plurality of ventilation holes 36 to the dispensing port 52b and supplying outside air taken in from the dispensing port 52b to the accommodation space 2s via the plurality of ventilation holes 36.
Near one end 51a of the extension nozzle 51, a locally enlarged flange portion 51f is provided. On both sides of the extension nozzle 51 when the opening of the other end 51b is viewed from the front, flat surfaces 51e called so-called D-cuts are respectively formed so as to form a pair. Note that the ventilation pipe 34 and the extension nozzle 51 can be integrally formed of a thermoplastic resin or the like.
The cock 52 is connected to the other end 51b of the extension nozzle 51. The cock 52 has a supply port 52a, a dispensing port 52b, and a dispensing passage 52p. In the cock 52, the dispensing port 52b communicates with the supply port 52a via the dispensing passage 52p. The supply port 52a of the cock 52 is connected to the other end 51b of the extension nozzle 51 so as to communicate with the passage 51p of the extension nozzle 51.
A fitting groove 51g is formed on the outer periphery of the extension nozzle 51 on the side of the other end 51b. A fitting claw portion 52c is formed at the supply port 52a of the cock 52. By engaging the claw portion 52c of the cock with the groove 51g of the extension nozzle 51, the cock 52 is fitted to the other end 51b of the extension nozzle 51 and detachably attached thereto. Thereby, the cock 52 can be replaced according to the type and amount of the content 10 accommodated in the inner bag 2.
The cock 52 further comprises a dispensing valve 55. The dispensing valve 55 is provided in the dispensing passage 52p between the supply port 52a and the dispensing port 52b, and is configured to be able to switch between supplying and stopping the supply of the content 10.
The plug 4B further comprises a nut member 53 that connects one end 51a of the extension nozzle 51 to the discharge opening 12 of the spout member 12a of the inner bag 2. The nut member 53 is provided so as to surround the one end 51a side of the extension nozzle 51 and the outer periphery of the spout member 12a. A female thread portion 53a capable of screwing with a male thread portion 12b formed on the outer peripheral surface of the spout member 12a is formed on the inner peripheral surface of one end side (the upper end side in FIG. 10) of the nut member 53. An engagement hook 53b capable of engaging with the flange portion 51f of the extension nozzle 51 is formed on the inner peripheral surface of the other end side (the lower end side in FIG. 10) of the nut member 53.
That is, when the female thread portion 53a of the nut member 53 is screwed onto the male thread portion 12b of the spout member 12a, the engagement hook 53b of the nut member 53 engages with the flange portion 51f of the extension nozzle 51 along with the screwing, and pulls the flange portion 51f along the axial direction so as to bring it close to the discharge opening 12 of the spout member 12a. Thereby, the nut member 53 fastens the extension nozzle 51 to the spout member 12a of the inner bag 2. However, the connection between the plug and the discharge opening of the spout member is not limited to connection by the nut member 53. For example, the plug and the discharge opening can be connected by pushing the plug into the discharge opening of the spout member in the axial direction (plug-in type connection structure), or the plug and the discharge opening can be connected by connecting a flange portion formed on the plug and a flange portion formed on the spout member to each other by locking, welding, or fitting (flange-type connection structure).
In such a bag-in-box 1B relating to this embodiment, at least a part of the extension nozzle 51 of the plug 4B extends in a direction inclined with respect to the axis Z of the ventilation pipe 34. Therefore, by adjusting the angle (rotation angle) and length of the extension nozzle 51 around the axis Z, the cock 52 can be arranged forward of the front of the outer box 3. Further, since the flat surfaces 51e are formed as a pair on both sides of the extension nozzle 51, the extension nozzle 51 can be reliably clamped by a U-shaped holder, clamp, or the like, and the direction of the extension nozzle 51 can be reliably fixed.
Therefore, according to the bag-in-box 1B relating to the present embodiment, not only can the same effects as those of the above-described embodiment be obtained, but also the following effects can be obtained. That is, when dispensing content 10 from the bag-in-box 1B, if the cock 52 is located directly below the outer box 3, the user's hand hits the outer box 3, making it difficult to operate the dispensing valve 55.
At this time, by arranging the cock 52 forward of the front of the outer box 3, the cock 52 can be operated comfortably. Further, by clamping the pair of flat surfaces 51e of the extension nozzle 51 with a U-shaped holder, clamp, or the like, the cock 52 can be easily positioned and fixed.

[Third Embodiment]

A third embodiment of a bag-in-box relating to the present invention will be described based on FIGS. 11 to 13. However, for parts similar to those in the above-described embodiments, descriptions overlapping with the descriptions in the above-described embodiments will be omitted by using the same reference numerals as those used in the description of the above-described embodiments.
The bag-in-box relating to this embodiment comprises an inner bag 2 and an outer box 3, and as shown in FIG. 11, comprises a plug 4C for dispensing content 10. That is, the bag-in-box 1C relating to this embodiment comprises a plug 4C instead of the plug 4B of the bag-in-box 1B relating to the above-described embodiment.
As shown in FIGS. 11 and 12, the plug 4C comprises a ventilation pipe 34, an extension nozzle 51C, a cock 52, and a nut member 53C. Near one end 51a of the extension nozzle 51C, a pair of guide rings 51c and 51d are provided in an integrated structure with the extension nozzle 51C together with a flange portion 51f.
The pair of guide rings 51c and 51d are located closer to the one end 51a side of the extension nozzle 51C than the flange portion 51f. The guide ring 51c is provided so as to be flush with one end 51a of the extension nozzle 51C. The guide ring 51c is formed in a tapered shape in which the outer diameter becomes smaller toward the one end 51a side (ventilation pipe 34 side) than toward the other end 51b side (cock 52 side) of the extension nozzle 51C.
The guide ring 51d is adjacent to the flange portion 51f and is provided with a space so as to form a groove with the guide ring 51c. An O-ring 54, which is a seal member, is fitted into the groove between the guide rings 51c and 51d.
That is, as the ventilation pipe 34 of the plug 4C is inserted into the discharge opening 12 of the spout member 12a of the inner bag 2, the guide rings 51c and 51d of the extension nozzle 51C guide the discharge opening 12 of the spout member 12a to abut on the flange portion 51f. At this time, since the guide ring 51c of the extension nozzle 51C has a tapered shape, the spout member 12a can be reliably guided without being caught by the discharge opening 12 when inserted into the discharge opening 12 of the spout member 12a.
Further, the space between the discharge opening 12 of the spout member 12a of the inner bag 2 and the extension nozzle 51C is sealed by the O-ring 54 fitted into the groove between the guide rings 51c and 51d of the extension nozzle 51C. Thereby, leakage of the content 10 from between them is reliably prevented.
As shown in FIG. 13, the nut member 53C is formed by assembling a plurality of (two in this embodiment) parts divided along the radial direction, specifically, a pair of semi-nut parts 53Ca and 53Cb each having a semi-circular arc shape. One semi-nut part 53Ca has convex portions 53d projecting in a substantially L-shape formed on end faces 53c on both sides in the circumferential direction. The other semi-nut part 53Cb has concave portions 53f recessed in a substantially T-shape formed on end faces 53e on both sides in the circumferential direction.
That is, the end faces 53c of the one semi-nut part 53Ca and the end faces 53e of the other semi-nut part 53Cb are brought into contact so that the L-shaped convex portions 53d of the one semi-nut part 53Ca are inserted into the T-shaped concave portions 53f of the other semi-nut part 53Cb. Then, the semi-nut parts 53Ca and 53Cb are slid relative to each other in opposite directions along the axial direction so that the convex portions 53d are caught in the concave portions 53f. Thereby, the semi-nut parts 53Ca and 53Cb are integrally connected and fixed to each other via the convex portions 53d and the concave portions 53f, and the axial end faces of the semi-nut parts 53Ca and 53Cb become flush with each other, forming one nut member 53C.
In such a bag-in-box 1C relating to this embodiment, the plug 4C is such that the nut member 53C is formed by assembling the semi-nut parts 53Ca and 53Cb. Therefore, the nut member 53C can be positioned from the outside near one end 51a of the extension nozzle 51C without having to pass the nut member 53C through the ventilation pipe 34 in advance.
Therefore, according to the bag-in-box 1C relating to the present embodiment, not only can the same effects as those of the above-described embodiments be obtained, but also the following effects can be obtained. That is, after the ventilation pipe 34 of the plug 4C is inserted into the discharge opening 12 of the spout member 12a of the inner bag 2 and the extension nozzle 51C is fitted to the discharge opening 12, the semi-nut parts 53Ca and 53Cb of the nut member 53C are assembled so as to surround the vicinity of the one end 51a of the extension nozzle 51C from the outside. Thereby, the nut member 53C can be easily positioned near one end 51a of the extension nozzle 51C without passing the nut member 53C through the ventilation pipe 34 in advance, and workability can be significantly improved.

In the present embodiment, the convex portions 53d projecting in a substantially L-shape are formed on one semi-nut part 53Ca, and the concave portions 53f recessed in a substantially T-shape are formed on the other semi-nut part 53Cb, so that the semi-nut parts 53Ca and 53Cb can be separably connected and fixed to each other. However, the present invention is not limited thereto. As a modification of the present embodiment, for example, by forming spherically projecting convex portions on one semi-nut part and forming spherically recessed concave portions on the other semi-nut part, it is also possible to connect and fix the pair of semi-nut parts to each other inseparably.
Further, in the present embodiment, the nut member 53C is configured by assembling a pair of semi-nut parts 53Ca and 53Cb each having a semi-circular arc shape divided into two along the radial direction. However, the present invention is not limited thereto. As a modification of the present embodiment, for example, it is possible to configure a nut member by assembling a set of split nut parts each having an arc shape divided into three or more along the radial direction, that is, by assembling a plurality of parts divided along the radial direction.

EXAMPLES

Examples conducted to confirm the effects of the bag-in-box relating to the present invention will be described below, but the present invention is not limited only to the specific examples described below.

[Example 1]

In Example 1, four types of plug samples A to D having ventilation pipes 34 of different lengths and a plug sample α without a ventilation pipe 34 were prepared, and the amount of residual liquid of the content 10 when the content 10 was dispensed from the inner bag 2 accommodated in the outer box 3 was evaluated. For the outer box 3, a flat shape with internal dimensions of width (W) 97 mm × depth (D) 275 mm × height (H) 395 mm was applied. The plug was set so as to be located at a bottom corner of the outer box 3. The diameter of the dispensing port 33 of the plug was 10 mm. The lengths of the ventilation pipes 34 of samples A to D were 70 mm, 60 mm, 50 mm, and 40 mm, respectively. Then, each inner bag 2 was filled with 10 kg of shampoo as the content 10. The results are shown in Table 1 below.

[Table 1]

Sample	Length of ventilation pipe	Number of times	Amount of residual liquid (g)
A	70 mm	1	227.8
		2	287.1
		3	289.5
B	60 mm	1	287.9
		2	254.4
		3	201.7
C	50 mm	1	255.9
		2	239.5
		3	288.9
D	40 mm	1	238.6
		2	310.1
		3	259.9
α	0 mm (None)	1	368.0

As shown in Table 1 above, in the case of sample α where the length of the ventilation pipe 34 was 0 mm, that is, there was no ventilation pipe 34, the amount of residual liquid exceeded 360 g. In contrast, when samples A to D with ventilation pipe 34 lengths of 40 mm to 70 mm were used, the amount of residual liquid was less than 350 g in all trials. In particular, when samples A to C with ventilation pipe 34 lengths of 50 mm to 70 mm were used, the amount of residual liquid was less than 300 g in all trials. This result is considered to be because when the length of the ventilation pipe 34 is long, it is possible to more reliably prevent all of the plurality of ventilation holes 36 from being blocked by the contraction of the inner bag 2. From the results in Table 1, it was confirmed that the content 10 can be stably dispensed by providing the ventilation pipe 34, and in particular, it was confirmed that the content 10 can be more stably dispensed when the length of the ventilation pipe 34 is 50 mm to 70 mm.

[Example 2]

In Example 2, three types of bag-in-box 1 samples E to G in which the plug 4 was arranged at different positions were prepared, and the amount of residual liquid of the content 10 when the content 10 was dispensed from the inner bag 2 was evaluated. The size of the outer box 3 and the diameter of the dispensing port 33 of the plug 4 were the same as those in Example 1. The lengths of the ventilation pipes 34 were all 60 mm. In sample E, the plug 4 was taken out from the outer box 3 through an opening formed in the center of the bottom surface 21 of the outer box 3. In sample F, the plug 4 was taken out from the outer box 3 through an opening formed in a corner of the bottom surface 21 of the outer box 3. In sample G, the plug 4 was taken out to the outside of the outer box 3 through an opening formed in the lower part of the side surface 23 of the outer box 3. Note that the content 10 was the same as in Example 1. The results are shown in Table 2 below.

[Table 2]

Sample	Position of plug	Number of times	Amount of residual liquid (g)
E	Center of bottom surface	1	239.9
		2	218.8
		3	267.5
F	Corner of bottom surface	1	209.1
		2	211.2
		3	215.5
G	Lower part of side surface	1	1223.7
		2	982.4
		3	1199.8

As shown in Table 2 above, it was confirmed that the amount of residual liquid of the content 10 when using sample G was larger than the amount of residual liquid of the content 10 when using sample E or sample F. This result is considered to be because liquid pressure is less likely to act on the plug 4 when the plug 4 is installed on the side surface 23. Note that compared to sample E, the amount of residual liquid of sample F was smaller and more stable. From the results shown in Table 2, it was confirmed that the amount of residual liquid of the content 10 can be reduced by taking out the plug 4 from the opening formed in the bottom surface 21.

INDUSTRIAL APPLICABILITY

Since the bag-in-box relating to the present invention can easily suppress the remaining of contents, it can be utilized extremely beneficially in industry.

EXPLANATION OF REFERENCE SIGNS

1, 1A, 1B, 1C: Bag-in-box
2: Inner bag
2a: Corner portion
2b: Side
2c: Heat seal (shoulder seal)
2d: Triangular portion
2s: Accommodation space
3: Outer box
3a: Opening
4, 4A, 4B, 4C: Plug
10: Content
11: Accommodating portion
12: Discharge opening
12a: Spout member
12b: Male thread portion
21: Bottom surface
22: Top surface
23: Side surface
30: Main body portion
30p: Dispensing passage
31: Proximal end portion
32: Distal end portion
33: Dispensing port
34, 34A, 34B: Ventilation pipe
35, 35A: Opening
36, 36B: Ventilation hole
37: Dispensing valve
38: Handle
40: Region
42: Outside air (air)
51, 51C: Extension nozzle
51a: One end
51b: Other end
51c, 51d: Guide ring
51e: Flat surface
51f: Flange portion
51g: Groove
52: Cock
52a: Supply port
52b: Dispensing port
52c: Claw portion
52p: Dispensing passage
53, 53C: Nut member
53Ca, 53Cb: Semi-nut part
53a: Female thread portion
53b: Engagement hook
53c: End face
53d: Convex portion
53e: End face
53f: Concave portion
54: O-ring
55: Dispensing valve

Claims

A bag-in-box (1) comprising:
a flexible inner bag (2) forming an accommodation space (2s) for accommodating a content (10);

an outer box (3) accommodating the inner bag (2); and

a plug (4) having a dispensing port (33) configured to communicate with the accommodation space (2s) of the inner bag (2) and to dispense the content (10) from the accommodation space (2s);

wherein the dispensing port (33) is configured to be capable of taking in outside air.
The bag-in-box (1) according to claim 1, wherein:
the dispensing port (33) has a diameter (D1) capable of taking in outside air; and

the diameter (D1) of the dispensing port (33) is 10 mm or more and 30 mm or less.
The bag-in-box (1) according to claim 2, wherein the diameter (D1) of the dispensing port (33) is 12 mm or more and 28 mm or less.
The bag-in-box (1) according to any one of claims 1 to 3, wherein:
the inner bag (2) comprises a spout member (12a) having a discharge opening (12) for discharging the content (10); and

the plug (4) comprises a ventilation pipe (34) configured to communicate with the dispensing port (33) and to be inserted into the accommodation space (2s) of the inner bag (2) through the discharge opening (12) of the spout member (12a), and a connecting portion configured to connect with the discharge opening (12) of the spout member (12a).
The bag-in-box (1) according to claim 4, wherein:
the connecting portion of the plug (4) includes a nut member (53C) configured to connect with the discharge opening (12) of the spout member (12a); and

the nut member (53C) is formed by assembling a plurality of parts (53Ca, 53Cb) divided along a radial direction.
The bag-in-box (1) according to claim 4, wherein the connecting portion of the plug (4) has a structure in which a flange portion formed on the plug (4) and a flange portion formed on the spout member are connected to each other by locking, welding, or fitting.
The bag-in-box (1) according to any one of claims 4 to 6, wherein the ventilation pipe (34) of the plug (4) has a ventilation portion for supplying outside air (42) taken in from the dispensing port (33) to the accommodation space (2s) of the inner bag (2).
The bag-in-box (1) according to claim 7, wherein the ventilation portion is a plurality of ventilation holes (36) opening toward the accommodation space (2s) of the inner bag (2) or a mesh portion provided in the ventilation pipe (34).
The bag-in-box (1) according to claim 8, wherein:
the ventilation pipe (34) of the plug (4) extends along an axial (Z) direction; and

the ventilation holes (36) open toward a direction intersecting the axial (Z) direction, or the ventilation holes (36) are slits having an axis parallel to the axial (Z) direction.
The bag-in-box (1B, 1C) according to any one of claims 7 to 9, wherein the plug (4B, 4C) further comprises:
a cock (52) having the dispensing port (52b); and

an extension nozzle (51, 51C) provided between the ventilation pipe (34) and the cock (52) and configured to cause the ventilation portion and the dispensing port (52b) to communicate with each other;

wherein at least a part of the extension nozzle (51, 51C) extends in a direction inclined with respect to the axial (Z) direction.
The bag-in-box (1B, 1C) according to claim 10, wherein:
the connecting portion of the plug (4B, 4C) has an engagement hook (53b) capable of engaging with a flange portion (51f) formed on the extension nozzle (51, 51C) of the plug (4B, 4C); and

the connecting portion of the plug (4B, 4C) is a nut member (53, 53C) configured to fasten the extension nozzle (51, 51C) and the spout member (12a) by engagement between the flange portion (51f) and the engagement hook (53b) accompanying thread engagement with a male thread portion (12b) formed on the spout member (12a) of the inner bag (2).
The bag-in-box (1) according to any one of claims 1 to 11, wherein the dispensing port (33) of the plug (4A) has a larger diameter than the discharge opening (12) of the spout member (12a) of the inner bag (2).
The bag-in-box (1) according to any one of claims 1 to 12, wherein the inner bag (2) has no opening other than the dispensing port (33).
The bag-in-box (1) according to any one of claims 1 to 13, wherein:
the inner bag (2) has an accommodating portion (11) forming the accommodation space (2s); and

the accommodating portion (11) comprises a flexible film.
The bag-in-box (1) according to claim 14, wherein the rigidity of the film is 30 mN or more and 300 mN or less.
A method of using the bag-in-box (1) according to any one of claims 1 to 15, comprising:
an intake step of performing dispensing of the content from the inner bag (2) via the dispensing port (33) and performing intake of outside air into the inner bag (2) via the dispensing port (33);

optionally further comprising:
before the intake step, a starting step of starting the dispensing of the content (10) in the inner bag (2) and performing only the dispensing of the content from the inner bag (2) via the dispensing port (33), and/or

after the intake step, a stopping step of stopping the dispensing of the content from the inner bag (2) via the dispensing port (33) and stopping the intake of outside air into the inner bag (2) via the dispensing port (33).