US20140185966A1

US20140185966A1 - Gusset Bag, Spout-Attached Gusset Bag, And Method Of Manufacturing The Same

Info

Publication number: US20140185966A1
Application number: US14/241,434
Authority: US
Inventors: Kazuhiro Umenaka
Original assignee: Hosokawa Yoko KK
Current assignee: Hosokawa Yoko KK
Priority date: 2011-08-31
Filing date: 2012-08-27
Publication date: 2014-07-03
Also published as: JP2013049458A; WO2013031723A1

Abstract

The gusset bag includes an opposing pair of flat surface sections and an opposing pair of side surface sections folded inward. Moreover, the pair of flat surface sections and the pair of side surface sections includes a first film material that forms a first flat surface section and at least a first side surface section, and a second film material that forms the other section thereof Furthermore, a side edge seal section is formed in which a side edge section of the first film material and a side edge section of the second film material are sealed.

Description

TECHNICAL FIELD

The present invention relates to a gusset bag, a spout-attached gusset bag, and a method of manufacturing the same.
Priority is claimed on Japanese Patent Application No. 2011-188309, filed Aug. 31, 2011, the content of which is incorporated herein by reference.

BACKGROUND ART

For a packaging bag for liquid or semi-liquid contents such as jelly beverages, standing pouches or flat bottom type gusset bags are used. Especially for the purpose of storing jelly beverages, a gusset bag is widely used, whose contents can be easily pushed out by being squeezed by hand.
For example, as shown in FIGS. 12 and 13, a spout-attached gusset bag 101 is known that comprises a gusset bag 110 which stores the contents, and a spout 120 which is attached to the gusset bag 110 and dispenses the contents from the gusset bag 110 (for example, refer to Patent Document 1). The gusset bag 110 is provided with an opposing pair of flat surface sections 111, and a pair of side surface sections 112 which connect the side edges of the two flat surface sections 111 and are folded inward opposite to each other.
In the spout-attached gusset bag 101, four side edge seal sections 113 are formed by the side edge sections of the flat surface sections 111 and the side edge sections of the side surface sections 112 being heat sealed.

DOCUMENT OF RELATED ART

Patent Document

[Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2004-196414

SUMMARY OF INVENTION

Technical Problem

However, there is a case in which a user feels pain when he or she squeezes the spout-attached gusset bag 101 strongly by hand, and a side edge seal section 113 touches the hand. That is, the side edge seal section 113 is formed such that it projects toward the outside of the gusset bag 110, the stiffness of the side edge seal section 113 is high, and the end 113 a is relatively sharp. Therefore, there is a case in which, when a user squeezes it by hand, he or she feels pain by the end 113 a cutting into the hand. In particular, in the case where the contents are a jelly beverage or the like, normally a user ingests the contents by pushing them out by squeezing the gusset bag 110 by hand. Therefore, it is desirable to reduce the pain felt when squeezing the gusset bag 110 by hand.
It is an object of the present invention to provide a gusset bag that can reduce the pain that a user feels when he or she squeezes it by hand, and a spout-attached gusset bag in which a spout is attached to the gusset bag.
Furthermore, it is another object of the present invention to provide a method of manufacturing a gusset bag that can reduce the pain that a user feels when he or she squeezes it by hand, and a method of manufacturing a spout-attached gusset bag in which a spout is attached to the gusset bag.

Solution to Problem

According to a first aspect of the present invention, a gusset bag includes an opposing pair of flat surface sections and an opposing pair of side surface sections folded inward.
Moreover, the pair of flat surface sections and the pair of side surface sections includes a first film material that forms a first flat surface section and at least a first side surface section, and a second film material that forms the other section thereof. Furthermore, a side edge seal section is formed in which a side edge section of the first film material and a side edge section of the second film material are sealed.
According to a second aspect of the present invention, in the first aspect, the first film material forms the first flat surface section and the pair of side surface sections, and the second film material forms a second flat surface section.
According to a third aspect of the present invention, a spout-attached gusset bag includes a spout attached to the gusset bag of the first or the second aspect.
According to a fourth aspect of the present invention, a method of manufacturing a gusset bag is a method of continuously manufacturing the gusset bag of the second aspect, and includes the following steps (α1) and (α2).
(α1) a step of conveying a long first film material used to form a first flat surface section and a pair of side surface sections, together with a long second film material used to form a second flat surface section, in a state in which the first film material is folded such that a plurality of first flat surface sections and a plurality of pairs of side surface sections are formed in parallel in a longitudinal direction thereof, and
welding a part between adjacent side surface sections of the first film material to the second film material in the longitudinal direction and cutting them, welding each part from side surface sections positioned near both side edges of the first film material to the side edges, to the second film material in the longitudinal direction and cutting them, and obtaining a plurality of cylindrical film materials, each cylindrical film material including flat surface sections and side surface sections with two side edge seal sections formed.
(α2) a step of welding and cutting the cylindrical film material in a width direction thereof, and separating the cylindrical film material into a plurality in the longitudinal direction.
According to a fifth aspect of the present invention, a method of manufacturing a spout-attached gusset bag uses the method of manufacturing a gusset bag of the fourth aspect, and includes attaching a spout to each top part of cylindrical film materials separated in the longitudinal direction when sealing the top part.

Effects of Invention

According to the gusset bag and the spout-attached gusset bag of the present invention, it is possible to reduce the pain that a user feels when he or she squeezes it by hand.
Furthermore, according to the method of manufacturing a gusset bag of the present invention, it is possible to obtain a gusset bag that can reduce the pain that a user feels when he or she squeezes it by hand.
Moreover, according to the method of manufacturing a spout-attached gusset bag of the present invention, it is possible to obtain a spout-attached gusset bag in which a spout is attached to a gusset bag that can reduce the pain that a user feels when he or she squeezes it by hand.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front view showing a spout-attached gusset bag of an embodiment of the present invention.

FIG. 2 is a rear view of the spout-attached gusset bag of FIG. 1.

FIG. 3 is a cross-sectional view through straight line I-I′ of the spout-attached gusset bag of FIG. 1.

FIG. 4 is a perspective view showing how contents are stored in the spout-attached gusset bag of FIG. 1.

FIG. 5 is an enlarged front view of the vicinity of an upper seal section of the spout-attached gusset bag of FIG. 1.

FIG. 6 is a cross-sectional view through straight line II-II′ of the spout-attached gusset bag of FIG. 5.

FIG. 7 is a perspective view showing a manufacturing process of a spout-attached gusset bag of an embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a manufacturing process of a spout-attached gusset bag of an embodiment of the present embodiment.

FIG. 9 is a perspective view showing a manufacturing process of a spout-attached gusset bag of an embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a manufacturing process of a spout-attached gusset bag of an embodiment of the present embodiment.

FIG. 11 is a cross-sectional view showing a modified example of a gusset bag of an embodiment of the present invention.

FIG. 12 is a front view showing a conventional spout-attached gusset bag.

FIG. 13 is a cross-sectional view through straight line of the spout-attached gusset bag of FIG. 12.

DESCRIPTION OF EMBODIMENTS

A gusset bag and a spout-attached gusset bag of the present invention have similar configurations except for the existence of a spout. That is, the gusset bag of the present invention has the same configurations as the spout-attached gusset bag except that it does not have a spout. Hereunder, an embodiment of a gusset bag and a spout-attached gusset bag of the present invention will be described in detail showing an example of a spout-attached gusset bag including a spout.
As shown in FIG. 1, a spout-attached gusset bag 1 of this embodiment includes a gusset bag 10, and a spout 20 attached in a fluid-tight manner to the top of the gusset bag 10. That is, the spout 20 is attached to one end side in the vertical direction (for example, the up-and-down direction in FIG. 1) of the gusset bag 10. In the following description, the edges of the gusset bag 10, and the edges of a flat surface section and a side surface section (described later) in the direction perpendicular to the vertical direction (for example, horizontal direction in FIG. 1) may be referred to as “side edges”.
The gusset bag 10, as shown in FIGS. 1 to 3, includes an opposing pair of flat surface sections 11 and 12, and an opposing pair of side surface sections 13 and 14, wherein each of the side surface sections 13 and 14 connects the facing side edges of the flat surface sections 11 and 12. The flat surface section 11 (first flat surface section) and the pair of side surface sections 13 and 14 are formed from a sheet of film material. That is, this gusset bag 10 is composed of two sheets of film material which are a first film material that forms the flat surface section 11 and the pair of side surface sections 13 and 14, and a second film material that forms the flat surface section 12 (second flat surface section).
The side surface sections 13 and 14 are folded toward the inside of the gusset bag 10 such that respective folding lines 13 a and 14 a correspond to each other.
As shown in FIGS. 2 and 3, in the gusset bag 10, two side edge seal sections 15 are formed, in which both side edge sections of the flat surface section 12 formed of the second film material, and the side edge sections of the side surface sections 13 and 14 formed of the first film material, are heat sealed (thermally welded). Furthermore, as shown in FIGS. 1 and 2, on the top of the gusset bag 10, an upper seal section 16 is formed in which the flat surface sections 11 and 12 and the side surface sections 13 and 14 are sealed. Moreover, on the bottom of the gusset bag 10, a lower seal section 17 is formed in which the opposing inner surfaces of the flat surface sections 11 and 12 and the side surface sections 13 and 14 are heat sealed. In this manner, the gusset bag 10 is formed.
Accordingly, as shown in FIG. 4, the spout-attached gusset bag 1 can store contents in the gusset bag 10.
In the upper seal section 16, the opposing inner surfaces of the flat surface sections 11 and 12 and the side surface sections 13 and 14 are heat sealed. Furthermore, in the upper seal section 16, it is preferable that the contact surfaces of the side surface section 13 be sealed and the contact surfaces of the side surface section 14 be sealed. The sealing of the contact surfaces of the side surface section 13 and the contact surfaces of the side surface section 14 in the upper seal section 16 may be performed for example while forming seal sections 18 as shown in FIGS. 5 and 6. In the seal sections 18, two punch holes are formed in opposing locations in the vicinities of the side edges of each of the side surface sections 13 and 14, and the inner surfaces 11 a and 12 a of the flat surface sections 11 and 12 are heat sealed in the punch holes. Moreover, the contact surfaces of the side surface section 13 and the contact surfaces of the side surface section 14 in the upper seal section 16 may be directly glued by an adhesive, a heat seal using a film having heat sealing characteristics, or a double-sided adhesive tape.
In the gusset bag 10 of the spout-attached gusset bag 1, since the side edge sections of the first film material and the side edge sections of the second film material are sealed, two side edge seal sections are formed. As a result, compared with a conventional gusset bag having four side edge seal sections formed, the number of side edge seal sections that touch the hand is less, so that the pain that a user feels when he or she squeezes it by hand can be reduced.
Furthermore, in the spout-attached gusset bag 1, the flat surface section 11 and the side surface sections 13 and 14 of the gusset bag 10 are formed of a sheet of film material. Accordingly, as shown in FIG. 4, no side edge seal section is formed near the flat surface section 11 of the gusset bag 10, and there is no protruding section. By so doing, in the case where the gusset bag 10 is gripped by hand from the side near the flat surface section 11, since the part of the gusset bag 10 that touches the palm is smooth, the pain that a user feels can be further reduced.
It is preferable that the width d₁(refer to FIG. 3) of the flat surface section 12 formed of the second film material be within ±5 mm of the width d₂(refer to FIG. 3) of the flat surface section 11 formed of the first film material. By so doing, it is possible to more easily manufacture the gusset bag 10 that enables a reduction in the pain that a user feels when he or she holds it.
The opposing pair of flat surface sections 11 and 12 form the front surface and the rear surface of the spout-attached gusset bag 1, respectively. In the present invention, the flat surface section 11 may be used as the front surface and the flat surface section 12 may be used as the rear surface, or the flat surface section 12 may be used as the front surface and the flat surface section 11 may be used as the rear surface.
Examples of a first film material that forms the flat surface section 11 and the side surface sections 13 and 14 include a single layer film or a laminated film having a multilayer structure. The first film material is preferably a laminated film from the point that it can provide a variety of functions, and is more preferably a laminated film that has an innermost layer that can be heat sealed, a functional layer, and an outermost layer.
Examples of a film used as the innermost layer include a non-oriented film formed of one or more selected from a group consisting of polyolefin resins such as low-density polyethylene (LDPE), medium-density polyethylene, high-density polyethylene, polypropylene (PP), and linear low-density polyethylene (LLDPE), mixed resins thereof, an ionomer resin, an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid copolymer, an ethylene-acrylic acid methyl copolymer, and an ethylene-methacrylic acid copolymer.
The thickness of the innermost layer is preferably 30 to 200 μm.
For a film used as the outermost layer, a film having high mechanical suitability and printability is preferable. Examples thereof include films formed of synthetic resins such as polyethylene terephthalate, polyamide, polypropylene, polycarbonate, and polyacetal. These films may be non-oriented films, or oriented films stretched uniaxially or biaxially. For a film used as the outermost layer, in terms of printability, a uniaxially or biaxially oriented film is preferably employed.
Specific examples thereof include oriented plastic films such as biaxially oriented polyethylene terephthalate (PET), biaxially oriented polyamide (ONY), and biaxially oriented polypropylene (OPP).
In addition, if necessary, synthetic paper, cellophane, paper, nonwoven cloth or the like can also be used.
The thickness of the outermost layer is preferably 12 to 25 μm.
The functional layer can be appropriately selected in accordance with required functions such as gas barrier properties, mechanical toughness, flex resistance, pierce resistance, shock resistance, wear resistance, cold resistance, heat resistance, and chemical resistance.
Examples of a film used for the functional layer include metal foils such as aluminum, iron, copper, and tin, films such as polyethylene terephthalate, polyamide, polyvinyl chloride, polycarbonate, polyvinyl alcohol, and ethylene-vinyl acetate copolymer saponification product, films obtained by applying polyvinylidene chloride to the above films or by vapor-depositing an inorganic material such as aluminum, silicon oxide, aluminum oxide, indium oxide, tin oxide, zirconium oxide, and magnesium oxide on the above films, films of polyvinylidene chloride, and nonwoven cloth or a foamed film having heat insulating properties.
The functional layer may be a single layer or two or more layers.
It is sufficient if the thickness of the functional layer is a thickness that can satisfy the functions required for the gusset bag 10, and the thickness is preferably 6 to 20 μm.
Moreover, in the first film material, instead of providing a functional layer, a vapor-deposited film having a vapor-deposited layer provided thereon may be employed for a film used as an outermost film.
Examples of a vapor-deposited layer include inorganic materials such as aluminum, silicon oxide, aluminum oxide, indium oxide, tin oxide, zirconium oxide, magnesium oxide.
Specific examples of the first film material include, for example, a film formed of PET (12 μm)/Al (7 μm)/ONY (15 μm)/LLDPE (60 μm) in order from the outermost layer.
For the second film material that forms the flat surface section 12, the same film as the first film material that forms the flat surface section 11 and the side surface sections 13 and 14 can be employed. It is preferable that at least the innermost layer of the second film material be the same as the innermost layer of the first film material in terms of sealability.
As shown in FIGS. 1 and 2, the spout 20 includes an extraction tube 21 which is inserted into the gusset bag 10 so as to extract the contents, and a cap 22 which is screwed to the top part of the extraction tube 21 so as to close the extraction port (opening) of the extraction tube 21. The spout 20 is liquid-tightly attached to the upper seal section 16 by heat-sealing in a state in which the extraction tube 21 is sandwiched between the upper edge portions of the flat surface sections 11 and 12.
As a material of the spout 20, the material of at least a part of the extraction tube 21 which is sealed with the inner surface of the flat surface section 11 is a synthetic resin.
Examples of a synthetic resin which forms at least the sealing portion of the extraction tube 21 of the spout 20 include a polyolefin resin, a polyamide resin, a polyester resin, a (meth)acrylic resin, a vinyl chloride resin, a vinylidene chloride resin, polyether sulfone, an ethylene-vinyl alcohol copolymer and the like. Among them, a polyolefin resin is preferably used in terms of excellent workability and low cost.
Examples of a polyolefin resin include a polyethylene-based resin such as high-density polyethylene, medium-density polyethylene, high-pressure-process low-density polyethylene, linear low-density polyethylene, and an ethylene-vinyl acetate copolymer, an olefin-based elastomer such as an ethylene-a-olefin copolymer, a polypropylene-based resin such as polypropylene, an ethylene-propylene random copolymer, and an a-olefin-propylene random copolymer, a cyclic polyolefin resin and the like. These resins may be blended to improve the performance, or may be partially cross-linked for the purpose of improvement in heat resistance and the like.
The spout 20 may be formed of a single material, or may be formed to have a multilayer structure formed of various resin layers.
In terms of sealability, the resin which forms at least the sealing portion of the extraction tube 21 of the spout 20 is preferably the same as the resin which forms the innermost layer of the flat surface sections 11 and 12.

(Manufacturing Method)

As a method of manufacturing a gusset bag of the present invention, a method including the following step (α1) and step (α2) can be given. This manufacturing method is suitable for a case where the first film material forms one flat surface section (first flat surface section) and a pair of side surface sections, and the second film material forms the film material (the other flat surface section, second flat surface section) of the other section in the gusset bag.
(α1) a step of conveying a long first film material used to form a first flat surface section and a pair of side surface sections together with a long second film material used to form a second flat surface section, in a state in which the first film material is folded such that a plurality of first flat surface sections and a plurality of pairs of side surface sections are formed in parallel in a longitudinal direction thereof, and
welding a part between adjacent side surface sections of the first film material to the second film material in the longitudinal direction and cutting them, and welding each part from side surface sections positioned near both side edges of the first film material to the side edges, to the second film material in the longitudinal direction and cutting them, and obtaining a plurality of cylindrical film materials, each cylindrical material including flat surface sections and side surface sections with two side edge seal sections formed.
(α2) a step of welding and cutting the cylindrical film material in a width direction thereof (a direction perpendicular to the longitudinal direction and parallel to the flat surface section), and separating the cylindrical film material into a plurality in the longitudinal direction.
In the case of manufacturing a spout-attached gusset bag, in the step (α2), a spout is attached to each top part of cylindrical film materials separated in the longitudinal direction when sealing the top part.
Hereunder, an example of a spout-attached gusset bag 1 including a gusset bag 10 is described in detail.
Step (α1):
As shown in FIG. 7, a long first film material 10A used to form a flat surface section 11 and a pair of side surface sections 13 and 14 is conveyed using rollers or the like together with a long second film material 10B used to form a flat surface section 12, in a state in which the first film material 10A is folded such that a plurality of first flat surface sections 11 and a plurality of pairs of side surface sections 13 and 14 are formed in parallel in the longitudinal direction thereof.
Next, as shown in FIG. 8, parts between adjacent side surface sections 13 and 14 of the first film material 10A are heat sealed to the second film material 10B in the longitudinal direction. Furthermore, the part from the side surface section 13 positioned near one side edge of the first film material 10A to the side edge is heat sealed to the second film material 10B in the longitudinal direction. Moreover, the part from the side surface section 14 positioned near the other side edge of the first film material 10A to the side edge is heat sealed to the second film material 10B in the longitudinal direction. As a result, a plurality of heat seal sections 15A which becomes the side edge seal sections 15 is formed. Furthermore, the heat seal sections 15A of the first film material 10A and the second film material 10B are cut along the straight lines X of FIG. 8, that is, in the longitudinal direction at the central parts in the width direction of the heat seal sections 15A. As a result, as shown in FIG. 9, a plurality of cylindrical film materials is cut out, each cylindrical film material including flat surface sections 11 and 12 and side surface sections 13 and 14 with two side edge seal sections 15 formed.
Step (α2):
In the cylindrical film material obtained in step (α1), parts of the inner surfaces of the flat surface sections 11 and 12 and the side surface sections 13 and 14, which become the lower seal sections 17, are heat sealed along the straight lines Y of FIG. 9 which extend in the width direction, that is, at regular intervals in the longitudinal direction of the first film material 10A and the second film material 10B. Afterwards, the first film material 10A and the second film material 10B are cut along the straight lines Y, that is, at regular intervals in the longitudinal direction of the first film material 10A and the second film material 10B, and are separated into a plurality in the longitudinal direction, thereby obtaining bag-shaped film materials in which the lower seal sections 17 are formed at the bottom parts of the flat surface sections 11 and 12 and the side surface sections 13 and 14. After this cutting operation, the lower seal section 17 is formed at the bottom part of the bag-shaped film material, and the top part thereof is open.
Next, at the top part of the flat surface sections 11 and 12 and the side surface sections 13 and 14 of each of the bag-shaped film materials separated into a plurality, using heat sealing, the opposing inner surfaces of the flat surface sections 11 and 12 are sealed, the contact surfaces of the flat surface sections 11 and 12 and the side surface sections 13 and 14 are sealed, and the spout 20 is attached thereto. Furthermore, the contact surfaces of the side surface section 13 are sealed and the contact surfaces of the side surface section 14 are sealed, and as a result, the upper seal section 16 is formed.
For a method of sealing the contact surfaces of the side surface section 13 and the contact surfaces of the side surface section 14 at the upper seal section 16, the following method can be given as an example.
As shown in FIG. 10, two punch holes 13 b are formed in the vicinities of the side edges of the side surface section 13 so as to oppose each other. Similarly, two punch holes 14 b are formed in the vicinities of the side edges of the side surface section 14 so as to oppose each other. As shown in FIGS. 5 and 6, the inner surface 11 a of the flat surface section 11 and the inner surface 12 a of the flat surface section 12 which oppose each other are pressed together and heat sealed inside the formed punch holes 13 b, thereby forming a seal section 18. Similarly, the inner surface 11 a of the flat surface section 11 and the inner surface 12 a of the flat surface section 12 which oppose each other are pressed together and heat sealed inside the formed punch holes 14 b, thereby forming another seal section 18. In this manner, the contact surfaces of the side surface section 13 are sealed and the contact surfaces of the side surface section 14 are sealed.
Moreover, the method of sealing the contact surfaces of the side surface section 13 and the contact surfaces of the side surface section 14 at the upper seal section 16 is not limited to the above-described method. The contact surfaces of the side surface section 13 or the contact surfaces of the side surface section 14 may be glued and fastened using; an adhesive, a film having heat sealing characteristics, or a double-sided adhesive tape.
Using the above steps, the spout-attached gusset bag 1 can be obtained.
In the method of manufacturing a gusset bag and the method of manufacturing a spout-attached gusset bag of the present invention, it is preferable to use the above-described method in terms of ease of manufacturing. However, the present invention is not limited to the above-described method.
In step (α1), in order to cut out a plurality of cylindrical film materials including flat surface sections 11 and 12 and side surface sections 13 and 14 with two side edge seal sections 15 formed, cutting is performed after heat sealing in the longitudinal direction. However, welding and cutting may be performed at the same time by performing weld and cut sealing (a sealing method in which the material is welded by heat, and at the same time the welded part is cut) in the longitudinal direction.
Furthermore, in step (α2), among the operation of forming the lower seal section 17, the operation of cutting the cylindrical film material in the width direction and separating it into a plurality in the longitudinal direction, and the operation of attaching the spout 20 and forming the upper seal section 16, any operation may be performed first, or these operations may be performed at the same time. For example, after cutting the cylindrical film material in the width direction and separating it into a plurality in the longitudinal direction, the bottom part of each of the separated cylindrical film materials may be sealed, and finally the top part to which the spout is attached may be sealed.
In the gusset bag and the spout-attached gusset bag of the present invention as described above, since the pair of flat surface sections and the pair of side surface sections of the gusset bag are formed of two film materials of the first film material and the second film material, the number of side edge seal sections formed is two, which is a small number, so that it is possible to reduce the pain that a user feels when he or she squeezes it by hand. In particular, in the case where the first film material forms one flat surface section and a pair of side surface sections, no side edge seal section is formed on each side edge of the flat surface section formed of this first film material, so that the part that touches the palm is smooth. As a result, even when the contents are pushed out by squeezing the gusset bag by hand, the pain that the user feels can be further reduced.
The gusset bag and the spout-attached gusset bag of the present invention are not limited to the gusset bag 10 and the spout-attached gusset bag 1 described above. For example, the gusset bag and the spout-attached gusset bag of the present invention may include a notch or a cutoff line formed for opening the bag.
Furthermore, a gusset bag of the present invention may be a gusset bag 10C as shown in FIG. 11. In the gusset bag 10C, a first film material forms a flat surface section 11 (first flat surface section) and a side surface section 14 (first side surface section), and a second film material forms a flat surface section 12 (second flat surface section) and a side surface section 13 (second side surface section). That is, two side edge seal sections 15 may be formed at diagonally opposite positions in the widthwise cross-section of the gusset bag 10C.

INDUSTRIAL APPLICABILITY

The present invention can be widely used for a gusset bag and a spout-attached gusset bag that store contents, and for methods of manufacturing them

DESCRIPTION OF REFERENCE SIGNS

1 Spout-attached gusset bag
10, 10C Gusset bag
10A First film material
10B Second film material
11, 12 Flat surface section
13, 14 Side surface section
15 Side edge seal section
20 Spout

Claims

1. A gusset bag comprising:

an opposing pair of flat surface sections; and

an opposing pair of side surface sections folded inward,

wherein the pair of flat surface sections and the pair of side surface sections include a first film material that forms a first flat surface section and at least a first side surface section, and a second film material that forms the other section thereof, and

a side edge seal section is formed in which a side edge section of the first film material and a side edge section of the second film material are sealed.

2. The gusset bag according to claim 1, wherein the first film material forms the first flat surface section and the pair of side surface sections, and the second film material forms a second flat surface section.

3. A spout-attached gusset bag comprising a spout attached to the gusset bag according to claim 1.

4. A spout-attached gusset bag comprising a spout attached to the gusset bag according to claim 2.

5. A method of manufacturing a gusset bag, used to continuously manufacture the gusset bag according to claim 2, the method comprising:

(α1) a step of conveying a long first film material used to form a first flat surface section and a pair of side surface sections, together with a long second film material used to form a second flat surface section, in a state in which the first film material is folded such that a plurality of first flat surface sections and a plurality of pairs of side surface sections are formed in parallel in a longitudinal direction thereof, and

welding a part between adjacent side surface sections of the first film material to the second film material in the longitudinal direction and cutting them, welding each part from side surface sections positioned near both side edges of the first film material to the side edges, to the second film material in the longitudinal direction and cutting them, and obtaining a plurality of cylindrical film materials, each cylindrical film material including flat surface sections and side surface sections with two side edge seal sections formed; and

(α2) a step of welding and cutting the cylindrical film material in a width direction thereof, and separating the cylindrical film material into a plurality in the longitudinal direction.

6. A method of manufacturing a spout-attached gusset bag that uses the method of manufacturing a gusset bag according to claim 5, comprising attaching a spout to each top part of cylindrical film materials separated in the longitudinal direction when sealing the top part.