JP2017190178A - Gusset bag and method of manufacturing gusset bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gusset bag with an excellent appearance, and a method of manufacturing a gusset bag which prevents the contamination with a film piece and a debris into the inside of the bag in a process of closing a gusset part and can easily close the gusset part.SOLUTION: A gusset bag 50 which is provided with a pair of opposing flat surface parts 12A, 12B and a gusset part 14 folded to the inside of the bag includes an ultrasonic seal part 18 where the opposing surfaces forming outer surfaces of the gusset bag 50 in the gusset part 14 are joined to each other by ultrasonic irradiation and a joined part 16A where an edge part of the flat surface part 12A, 12B and an edge part of the gusset part 14 are joined. In the gusset bag 50, an ultrasonic irradiation mark is formed on a back surface side of a surface where the ultrasonic seal part 18 is formed in the gusset part 14.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gusset bag and a method for manufacturing a gusset bag.

  The bag is formed by, for example, a laminated film in which a sealant layer having heat-fusibility and a base material layer having heat resistance are laminated. The sealant layer forms the inner surface layer of the bag, and the base material layer forms the outer surface layer of the bag.

  As a method of joining laminated films to form a bag, a method by external heating in which heating is gradually progressed from the surface of the laminated film to the inside by heat conduction, radiation, convection, etc. by a heat source outside the laminated film. In addition, there is a method by internal heating in which the inside and the outside are heated simultaneously in parallel by the self-heating of the laminated film itself. As a method by external heating, there is a method using a hot plate seal (hereinafter also simply referred to as “heat seal”), an impulse seal or the like, and as a method using internal heating, there is a method using a high frequency seal or an ultrasonic seal.

As shown in FIG. 10, the gusset bag 100 includes a pair of opposed flat portions 102A and 102B and a pair of opposed lateral gusset portions 104 and 104 provided on both sides of the flat portions 102A and 102B. In the gusset bag 100, the inner surface layer 106 is a sealant layer having heat-fusibility, and the outer surface layer 108 is a base material layer having heat resistance.
For this reason, as shown in FIG. 11, even if the open end seal portion 110 using heat seal, for example, is applied to close the upper and lower portions of the flat portions 102A and 102B, both edges of the open end seal portion 110 are provided. In the portion 110A, the outer surface layers 108 of the lateral gusset portion 104 are not joined. As a result, the upper and lower portions of the horizontal gusset portion 104 are opened. In such a state, the appearance of the gusset bag 100 is inferior.
Further, in the boundary portion between the open end seal portion 110 and the content storage portion, the intersection 110B with the folded portion of the lateral gusset portion 104 is most likely to concentrate stress when the lateral gusset portion 104 is open. . For this reason, when the gusset bag 100 is accidentally dropped, the bag breakage may occur from the intersection 110B where the stress is concentrated.

  Therefore, as shown in FIG. 12, a gusset bag 100 has been developed in which both edge portions 110 </ b> A of the open end seal portion 110 that is the upper end of the lateral gusset portion 104 are joined and the opening of the lateral gusset portion 104 is closed. . Thereby, the external appearance of the gusset bag 100 is improved and bag breaking is prevented.

As a technique for closing the opening of the lateral gusset portion, Patent Document 1 discloses that a part of the laminated film of the lateral gusset portion is removed to provide a through hole, and the inner surface layers of the pair of flat portions are formed through the through hole. A gazette bag in which a pair of flat portions are integrated by bonding is disclosed.
However, in such a gusset bag, a small film piece generated by cutting to form a through hole is mixed into the inside of the gusset bag, or the film piece is conveyed to the next process to cause a seal failure. There is a possibility of waking up.
Furthermore, although a through-hole is provided in the horizontal gusset portion and the through-hole is closed by the flat portion, the flat portion is uneven where the through-hole is present, and the appearance is poor.

13 is a view showing a lower part of the gusset bag 120 having the bottom gusset portion 112, FIG. 13 (A) is a front view of the gusset bag 120, and FIG. 13 (B) is a perspective view of the bottom gusset portion 112. It is. In addition, the area | region shown by hatching is an area | region where the laminated | multilayer film which forms the gusset bag 120 are joined.
When the bottom gusset portion 112 is joined to the pair of flat portions 102A and 102B, the outer surface layer 108 that is the outer surface layer is formed of a heat-resistant base material layer. Normally it is not joined.
Therefore, when the bottom gusset portion 112 and the flat portions 102A and 102B are joined by cutting out a part of the edge of the bottom gusset portion 112, the inner surface layer 106 of the flat portions 102A and 102B through the cut portions 112A. They are joined together. Thereby, a pair of plane part 102A, 102B is integrated, it prevents that a bottom opens in the edge part of the gusset bag 120, and the self-supporting function of the gusset bag 120 expresses.
However, in such a gusset bag 120, a small film piece generated by cutting to form the notch portion 112A is mixed into the gusset bag 120, or the film piece is conveyed to the next process. May cause a seal failure.
In this case as well, although the cutout portion 112A is blocked by the flat portion, the flat portion is uneven where the through-hole is present, and the appearance is poor.

  Therefore, in Patent Document 2, in a self-supporting bag having a bottom gusset portion, two cutting lines are provided on the bottom member, and a band-shaped portion provided between the two cutting lines is bent to form an unsealed portion in the bottom seal portion. A self-supporting packaging that can maintain its independence without the gusset on the bottom of the packaging bag being opened, with the front film and the back film of the two main body films being tightly sealed at the folded-back trace of the band-shaped part. A bag is disclosed.

  However, even in the self-supporting packaging bag of Patent Document 2, if the two cutting lines do not become parallel but intersect, it becomes a notch, and the film piece can be cut out from the bag and mixed into the gusset bag There is sex. In addition, since the band-like portion provided between the two cutting lines is bent and formed so as to be located at the unsealed portion in the ship bottom seal portion, the surface is uneven and the appearance is poor. Furthermore, there is a possibility that the gusset bag is greatly broken by extending the cutting line.

  Therefore, Patent Document 3 proposes a gusset bag in which the planar portion and the end portion of the gusset portion are heat-sealed and then irradiated with ultrasonic waves from above the heat-sealed portion to join the outer surfaces of the gusset portions. Yes.

Japanese Utility Model Publication No. 2-120342 JP 2009-90987 A International Publication No. 2015/1171736

  However, in patent document 3, since the ultrasonic irradiation trace formed when ultrasonic irradiation is visually recognized on the surface of a gusset bag, the external appearance of a gusset bag may be impaired.

  The present invention has been made in view of such circumstances, and it is easy to prevent film fragments and debris from being mixed in the bag in the process of closing the gusset bag having a good appearance and the gusset portion. It aims at providing the manufacturing method of the gusset bag which can close a gusset part.

The present invention has the following aspects.
[1] A gusset bag comprising a pair of opposed flat portions and a gusset portion folded inward of the bag,
Among the gusset parts, it has an ultrasonic seal part in which the opposing surfaces forming the outer surface of the gusset bag are joined by ultrasonic irradiation,
Having a joint where the edge of the planar portion and the edge of the gusset portion are joined;
A gusset bag in which ultrasonic irradiation marks are formed on the back side of the surface of the gusset portion where the ultrasonic seal portion is formed.
[2] The gusset bag according to [1], wherein the gusset portion is a lateral gusset portion.
[3] The gusset bag according to [1], wherein the gusset portion is a bottom gusset portion.
[4] The gusset bag according to any one of [1] to [3], wherein the ultrasonic seal portion and the joint portion overlap each other.
[5] A method for producing a gusset bag according to any one of [1] to [4],
A step of irradiating ultrasonic waves from the outside of the half-folded film for the gusset part, joining the opposing faces together, and forming an ultrasonic seal part; and
The manufacturing method of the gusset bag which has the process of joining the edge part of the film for plane parts, and the edge part of the said film for gusset parts, and forming a junction part.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the gusset bag which can close a gusset part easily while preventing a film piece and waste from mixing in in a bag in the process of closing a gusset part with a favorable external appearance. Can be provided.

It is a perspective view which shows the upper part of the gusset bag which concerns on 1st Embodiment of this invention. It is AA sectional drawing of FIG. 1 which expands and shows the junction part which concerns on 1st Embodiment of this invention partially. It is a perspective view which expands and shows the side gusset part which concerns on 1st Embodiment of this invention partially. It is a cross-sectional view which shows an example of the ultrasonic seal | sticker part formation process which joins a laminated | multilayer film by ultrasonic sealing. It is a front view which shows the lower part of the gusset bag which concerns on 2nd Embodiment of this invention. It is a perspective view which shows the upper part of the film for gussets half-folded. It is a perspective view which shows arrangement | positioning with the film for plane parts, and the film for gusset parts. It is a perspective view which shows the upper part of the gusset bag which formed the junction part in a junction part formation process. It is a perspective view which shows the upper part of a gusset bag with a mouth member. It is a perspective view which shows the upper part of the gusset bag which has a horizontal gusset part. It is a perspective view which shows the upper part of the gusset bag of the state which the upper part of the horizontal gusset part opened. It is a perspective view which shows the upper part of the gusset bag which closed the opening of the horizontal gusset part. It is a figure which shows the lower part of the gusset bag which has a bottom gusset part, (A) is a front view, (B) is a perspective view of a bottom gusset part.

  EMBODIMENT OF THE INVENTION Below, one embodiment of the manufacturing method of the gusset bag which concerns on this invention, and a gusset bag is described with reference to drawings.

<First Embodiment>
The first embodiment of the present invention will be described below.
A gusset bag 50 according to the first embodiment shown in FIG. 1 is provided as a pair of opposed flat portions 12A and 12B and gusset portions that are provided on both sides of the flat portions 12A and 12B and are folded inward of the bag. Are provided with a pair of lateral gusset portions 14, 14.

In the gusset bag 50 shown in FIG. 1, the pair of flat portions 12A and 12B are each formed of a single laminated film, and the pair of lateral gusset portions 14 and 14 are each formed of a single laminated film.
In the case of this form, as shown in FIG. 1, the joint 16 </ b> A is formed from the upper part to the lower part of the gusset bag 50.

As shown in FIG. 2, the laminated film 21 forms the inner surface of the gusset bag 50, forms the inner surface layer 22 having heat-fusibility, and the outer surface of the gusset bag 50, and has an outer surface having heat resistance. A surface layer 24 is laminated. That is, the inner surface layer 22 is a sealant layer, and the outer surface layer 24 is a base material layer.
The melting point of the resin forming the inner surface layer 22 is, for example, 170 ° C. or less, the melting point of the resin forming the outer surface layer 24 is higher than the melting point of the resin forming the inner surface layer 22, As an example, it is 250 ° C. or higher. Further, a functional layer as an intermediate layer may be laminated between the inner surface layer 22 and the outer surface layer 24 as necessary.

Examples of the film used as the inner surface layer 22 include polyolefin resins such as polyethylene and polypropylene such as low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene, or mixed resins, ionomer resins, and ethylene. -The unstretched film which consists of 1 or more types chosen from the group which consists of vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, and ethylene-methacrylic acid copolymer is mentioned. Alternatively, a layer made of these resins may be used.
In addition, as for the thickness of the inner surface layer 22, 30-200 micrometers is preferable.

As the film used as the outer surface layer 24, a film having good mechanical suitability and printability is preferable. For example, the film which consists of synthetic resins, such as a polyester type, a polyamide type, a polypropylene type, a polycarbonate type, a polyacetal type, is mentioned. These films may be unstretched films or stretched films stretched in a uniaxial direction or a biaxial direction. The film used as the outer surface layer 24 is preferably a stretched film stretched in a uniaxial direction or a biaxial direction from the viewpoint of printability.
Specific examples include stretched plastic films such as a biaxially stretched polyethylene terephthalate film, a biaxially stretched polyamide film, and a biaxially stretched polypropylene film. Further, if necessary, synthetic paper, cellophane, paper, non-woven fabric, etc. may be used.
As a film used for the outer surface layer 24, a vapor deposition film provided with a vapor deposition layer may be used. Examples of the vapor deposition layer include inorganic substances such as aluminum, silicon oxide, aluminum oxide, indium oxide, tin oxide, zirconium oxide, and magnesium oxide.
The outer surface layer 24 preferably has a thickness of 12 to 25 μm.

The intermediate layer is appropriately selected according to the required functions such as gas barrier properties, mechanical toughness, flex resistance, puncture resistance, impact resistance, wear resistance, cold resistance, heat resistance, chemical resistance, etc. it can.
As a film used for the intermediate layer, for example, a metal foil such as aluminum, iron, copper, tin, polyethylene terephthalate, polyamide, polyvinyl chloride, polycarbonate, polyvinyl alcohol, a saponified ethylene-vinyl acetate copolymer, Or films coated with polyvinylidene chloride, films deposited with inorganic materials such as aluminum, silicon oxide, aluminum oxide, indium oxide, tin oxide, zirconium oxide, magnesium oxide, films of polyvinylidene chloride, etc. Nonwoven fabric and foamed film that can be used.
The intermediate layer may be a single layer or two or more layers.
In addition, the thickness of an intermediate | middle layer should just be the thickness which can satisfy | fill the function requested | required of the gusset bag 50, and 6-20 micrometers is preferable.
For the laminated film 21, the inner surface layer 22, the outer surface layer 24 and, if necessary, the intermediate layer are bonded by a known method such as a dry laminating method using an adhesive or an extrusion laminating method using a heat-adhesive resin. Can be manufactured.

As shown in FIG. 2, the lateral gusset portion 14 forms an outer surface of the gusset bag 50, and opposing surfaces of the lateral gusset portion 14 (hereinafter also referred to as “outer surface”) are ultrasonic seal portions. An ultrasonic irradiation mark 19 is formed on the back surface (hereinafter also referred to as “inner surface”) of the surface on which the ultrasonic seal portion 18 is formed. That is, the lateral gusset portion 14 is half-folded so that the outer surface layers 24, 24 of the laminated film 21 face each other, and the outer surface layers 24 are joined together by the ultrasonic seal portion 18, and the inner surface layer 22 side. Has an ultrasonic irradiation mark 19.
As shown in FIG. 3, the ultrasonic seal portion 18 is formed on the outer surface layer 24 and the outer surface layer 24 of the lateral gusset portion 14.
In the first embodiment, the ultrasonic irradiation mark 19 is formed on the inner surface layer 22 side of the lateral gusset portion 14 as shown in FIG. The shape of the ultrasonic irradiation mark 19 in plan view is the same as the shape of the tip portion of the ultrasonic sealing machine, and is, for example, a circle or a rectangle. In addition, when pressed by the ultrasonic sealing machine, the inner surface layer side that comes in contact with the ultrasonic sealing machine becomes a concave portion, and the opposite inner surface layer side becomes a convex portion so that the two sheets are half-folded. The laminated films 21 and 21 of the overlapped lateral gusset portion 14 are deformed.

  As shown in FIG. 1, the edge portions of the plane portions 12 </ b> A and 12 </ b> B (“side edge portion” in this embodiment) and the edge portions of the lateral gusset portions 14 and 14 (“side edge portion” in this embodiment). ")" Is joined between the inner surface layers 22 and 22 of the laminated films 21 and 21 by the joining portions 16A, 16A, 16A and 16A.

Examples of the joining method of the joining part include a joining method by heat sealing using a hot plate seal in which a heated heat seal bar is pressed against a laminated film and then a cooled cooling bar is pressed. In addition, since the outer surface layer has heat resistance that does not melt at the temperature by heat sealing, it is not bonded by heat sealing.
As a joining method of the joining portion, other methods such as impulse sealing other than heat sealing may be used. Moreover, when the layer which comprises a laminated | multilayer film contains a polyvinyl chloride layer and a metal foil layer, it can be joined by a high frequency seal. Furthermore, other bonding methods other than ultrasonic sealing, such as bonding with an adhesive, may be used.

As described above, in the gusset bag 50 according to the first embodiment, the outer surface layers 24 and 24 of the laminated film 21 forming the lateral gusset portion 14 are joined by the ultrasonic seal portion 18. The joining of the ultrasonic seal portion 18 is performed, for example, near the upper end or the lower end (not shown) of the lateral gusset portion 14. The ultrasonic seal portion 18 according to the first embodiment has a narrower range than the joint portion 16A. That is, it is preferable that the ultrasonic seal portion 18 is entirely included in the region of the joint portion 16A.
If the ultrasonic seal portion 18 is not formed, the lateral gusset portion 14 is in an open state with the outer surfaces spaced apart. That is, the opening of the upper end portion and the lower end portion of the lateral gusset portion 14 is closed by the ultrasonic seal portion 18.

  The joining of the ultrasonic seal portion 18 is performed by ultrasonic sealing that is internal heating. This is because the outer surface layer of the laminated film has heat resistance and is not suitable for joining by external heating such as heat sealing.

In order to form the ultrasonic seal portion 18 of the gusset bag 50 according to the first embodiment, the outer surface layer 24 of the laminated film 21 is composed of the ultrasonic sealer 30 and the base 31, as shown in FIG. Ultrasonic sealing is performed by sandwiching the lateral gusset portion 14 that is half-folded with the inner surface facing outward so that the 24 faces each other. When the ultrasonic seal is applied, the outer surface layers 24 and 24 of the laminated film 21 forming the lateral gusset portion 14 rub against each other, and frictional heat is selectively generated by the rubbing. Are joined together to form an ultrasonic seal 18.
In the joining by the ultrasonic seal, scraps may be generated because the two surfaces to be joined are rubbed together. However, as shown in FIG. 4, the portion where scraps are generated by joining by ultrasonic sealing is a portion where the outer surface layers 24, 24 of the laminated film 21 forming the lateral gusset portion 14 are rubbed together. The portion where the ultrasonic seal portion 18 is formed is outside the gusset bag 50. For this reason, even if debris is generated by joining with an ultrasonic seal, the debris is not mixed in the bag because it is outside.

  In the horizontal gusset portion 14, an ultrasonic irradiation mark 19 is formed in a portion in contact with the ultrasonic sealer 30 on the inner surface side (that is, the back surface side of the ultrasonic seal portion 18). Since the planar portion 12A or 12B is overlapped and joined on the ultrasonic irradiation mark 19, the ultrasonic irradiation mark 19 is not visually recognized from the outside of the gusset bag. In addition, on the side where the concave portion of the ultrasonic irradiation mark 19 is formed, the flat portion 12A or 12B is covered on the concave portion to form the joint portion 16A, and the inner surface layer 22 is formed by heat sealing or the like. It seems that the step of the concave portion is relaxed by melting the resin of the film being formed, and it is difficult to visually recognize the presence or absence of the ultrasonic irradiation marks 19 from the outside of the gusset bag 50. On the other hand, on the side where the convex portion of the ultrasonic irradiation mark 19 is formed, the flat portion 12B or 12A is covered on the convex portion to form the joint portion 16A. For example, the joint portion is heat-sealed. In the case of bonding with, the convex portion of the ultrasonic irradiation mark 19 is crushed by the pressure of the heat seal bar when forming the bonding part, and it is possible to visually recognize the presence or absence of the ultrasonic irradiation mark 19 from the outside of the gusset bag. Have difficulty.

  As described above, the gusset bag according to the first embodiment is formed by a pair of opposed flat portions and a pair of opposed lateral gusset portions folded inward of the bag. And a gusset bag is provided with the junction part which inner surfaces joined the side edge part of the plane part, and the side edge part of the horizontal gusset part with inner surface layers of a laminated | multilayer film. Moreover, a gusset bag is equipped with the ultrasonic seal part which the outer surfaces which the horizontal gusset part opposes are outer surface layers of a laminated | multilayer film, and joined by ultrasonic seal | sticker. Further, the lateral gusset portion has ultrasonic irradiation marks on the inner surface side on the back surface side of the surface on which the ultrasonic seal portion is formed.

  Since the opening of the gusset portion of the gusset bag having the ultrasonic seal portion in the gusset portion is closed by the ultrasonic seal portion, even if the gusset bag is accidentally dropped, the occurrence of bag breakage is suppressed. . In addition, the ultrasonic irradiation mark formed on the back side of the ultrasonic seal part can be covered with a flat part, and it is difficult to visually recognize the presence or absence of the ultrasonic irradiation mark. be able to.

Second Embodiment
Hereinafter, a second embodiment of the present invention will be described.

FIG. 5 is a front view of the gusset bag 70 according to the second embodiment. In FIG. 5, the same components as those in FIG. 1 are denoted by the same reference numerals as those in FIG.
The gusset bag 70 according to the second embodiment is formed by a pair of plane portions 12A and 12B and a bottom gusset portion 40 that is a gusset portion. The bottom gusset portion 40 is formed by being folded inward between the pair of plane portions 12A and 12B at the lower part of the pair of plane portions 12A and 12B. In addition, the area | region shown by hatching is an area | region where the laminated | multilayer film which forms the gusset bag 70 are joined.

The flat surface portions 12 </ b> A and 12 </ b> B and the bottom gusset portion 40 are joined to each other at the lower surface of the gusset bag 70 by inner joint layers 42 of the laminated film.
Moreover, in the edge part (the "side edge part" in the case of this embodiment) of the gusset bag 70, the inner surfaces facing each other of the edge parts ("side edge part" in the case of this embodiment) of the plane parts 12A and 12B Are joined by the side joints 16 and 16 between the inner surface layers 22 and 22 of the laminated films 21 and 21, respectively, and the side edges of the plane parts 12A and 12B and the side edges of the bottom gusset part 40 are relative to each other. The inner surfaces to be joined are the inner surface layers 22 and 22 of the laminated films 21 and 21 and are joined by the joining portions 16A, 16A, 16A and 16A. The lower joint portion 42 may be a boat-shaped joint portion integrated with the joint portion 16A, and the boat-shaped joint portion may be appropriately provided with an unsealed portion 44 that is a region that is not joined within the lower joint portion 42. . Since the joining method is the same as that of the first embodiment, description thereof is omitted.

Here, the outer surface layers of the laminated film forming the bottom gusset portion 40 are joined together by the ultrasonic seal portion 18 that is a joint by ultrasonic seal.
For example, as shown in FIG. 5, the ultrasonic seal portion 18 is joined in the vicinity of the right end or the left end of the bottom gusset portion 40.
If the ultrasonic seal part 18 is not formed, the bottom gusset part 40 will be in the state where the outer surfaces separated and opened. That is, the opening of the right end and the left end of the bottom gusset portion 40 is closed by the ultrasonic seal portion 18.
Since joining by ultrasonic sealing is the same as in the first embodiment, description thereof is omitted.

  In addition, the ultrasonic seal part 18 should just be provided in one place on either side in the position which overlaps with the junction part 16A, but it is not restricted to this, For example, as shown in FIG. 5 according to the size of the gusset bag 70 A plurality of ultrasonic seal portions 18 may be provided in the longitudinal direction of the gusset bag 70.

  As described above, the gusset bag according to the second embodiment is formed of a pair of opposed flat portions and a bottom gusset portion that is folded inward of the bag. And a gusset bag is provided with the junction part which inner surfaces joined the side edge part of the plane part, and the side edge part of the bottom gusset part with the inner surface layers of laminated | multilayer film. Moreover, a gusset bag is provided with the ultrasonic seal part which the outer surfaces which the bottom gusset part opposes are outer surface layers of a laminated | multilayer film, and joined by ultrasonic seal | sticker. Furthermore, the bottom gusset portion has an ultrasonic irradiation mark on the inner surface side on the back surface side of the surface on which the ultrasonic seal portion is formed.

  Since the opening of the gusset portion of the gusset bag having the ultrasonic seal portion is closed by the ultrasonic seal portion, the occurrence of broken bags is suppressed even if the gusset bag is accidentally dropped. Moreover, self-supporting property can be provided to the obtained gusset bag by closing the bottom gusset portion with the ultrasonic seal portion. Furthermore, since the ultrasonic irradiation mark formed on the back side of the ultrasonic seal part can be covered with a flat part, and it is difficult to visually recognize the presence or absence of the ultrasonic irradiation mark, the gusset bag has a good appearance. be able to.

≪Gazette bag manufacturing method≫
Next, the manufacturing method of the gusset bag of this invention is demonstrated.
The method of manufacturing a gusset bag according to the present invention includes a step of irradiating ultrasonic waves from the outside of a half-folded film for a gusset portion and joining opposing surfaces to form an ultrasonic seal portion (ultrasonic seal portion formation). Step), and the step of joining the edge portion of the film for the flat portion and the edge portion of the film for the gusset portion to form the joint portion (joint portion forming step).
Hereinafter, although the details will be described taking the gusset bag 50 of the first embodiment as an example, the method of manufacturing the gusset bag of the present application is not limited to this.

<Ultrasonic seal part forming process>
As shown in FIG. 6, the lateral gusset portion film 14 ′ having the inner surface layer 22 and the outer surface layer 24 is half-folded along the longitudinal direction so that the outer surface layer 24 is on the inner side. At this time, the opposing pair of lateral gusset films 14 ′ and 14 ′ are arranged in parallel so that the half-folded fold line faces inward. Next, as shown in FIG. 4, the end portions of the half-folded lateral gusset portion films 14 ′ and 14 ′ are sandwiched between the ultrasonic sealing machine 30 and the base 31. As shown in FIG. 3, the outer surface layers 24, 24 of the lateral gusset portion film 14 ′ are joined with an ultrasonic seal to form an ultrasonic seal portion 18. At this time, an ultrasonic irradiation mark 19 is formed on the back side of the surface where the ultrasonic seal portion 18 is formed (that is, the inner surface layer 22 side).
Although ultrasonic irradiation conditions differ with laminated films to be used, a frequency of 20 to 40 kHz and an irradiation time of 0.1 to 0.5 seconds are preferable.

<Joint formation process>
As shown in FIG. 7, in the ultrasonic seal portion forming step, a pair of opposed lateral gusset films 14 ′ and 14 ′ in which the ultrasonic seal portion 18 and the ultrasonic irradiation mark 19 are formed are sandwiched therebetween. The pair of opposing flat portion films 12A ′ and 12B ′ are arranged so that the inner surface layers 22 of the two flat portion films 12A ′ and 12B ′ face inward. Furthermore, it arrange | positions so that the side edge part 13 of two film | membranes 12A 'and 12B' for plane parts and the side edge part 13 'of film 14' for horizontal gusset parts may overlap.
Next, the inner surface layers 22 of the side edge portion 13 of the plane portion film and the side edge portion 13 ′ of the lateral gusset portion film are joined along the longitudinal direction, and as shown in FIG. 16A, 16A, 16A, 16A are formed. Therefore, the ultrasonic irradiation marks 19 formed only on the back side of the surface where the ultrasonic seal portion 18 is formed are covered with the plane portion films 12A ′ and 12B ′. After that, a joint is formed at the upper edge or the lower edge to form a gusset bag 50 ′.
Examples of the method for forming the joint include a method that excludes ultrasonic sealing, such as heat sealing, impulse sealing, high frequency sealing, and bonding with an adhesive. Of these, heat sealing is preferable.
Among the methods for forming the joint, the heat sealing conditions vary depending on the laminated film used, but a temperature of 150 to 200 degrees, a time of 0.3 to 1.0 seconds, and a pressure of 0.3 to 0.7 MPa are preferable.

  According to the method for producing a gusset bag of the present invention, the outer surface layers of the lateral gusset portion film are bonded in advance by ultrasonic sealing, and therefore the inner surface layers are not rubbed with each other and no debris is generated. Therefore, it is possible to prevent film pieces and scraps from being mixed into the bag, and to close the gusset portion easily.

  As mentioned above, although this invention was demonstrated using said each embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various changes or improvements can be added to the above-described embodiments without departing from the gist of the invention, and embodiments to which the changes or improvements are added are also included in the technical scope of the present invention.

  For example, in the first embodiment, a bottom gusset portion may be further provided. In the second embodiment, a lateral gusset portion may be further provided.

  Further, in each of the above embodiments, the form in which the entire ultrasonic seal portion is included in the region of the joint portion or the lower joint portion has been described, but the present invention is not limited to this, and the ultrasonic seal portion It is good also as a form which a part or all does not contain in the area | region of a junction part or a lower junction part. In this case, since the ultrasonic irradiation trace does not overlap with the bonded portion, the step of the convex portion of the concave portion of the ultrasonic irradiation mark is not relaxed by the bonded portion, but the plane portion is not bonded to the ultrasonic irradiated mark. Since the ultrasonic wave is not irradiated from the outside of the gusset bag by being covered, it is difficult to visually recognize the presence or absence of the ultrasonic irradiation mark. On the other hand, when the laminated film has a metal foil such as aluminum, the metal foil may be broken at the concave or convex portions of the ultrasonic irradiation mark. When the ultrasonic seal part and the joint part do not overlap, the tear can be visually recognized from the inside of the gusset bag, but when the ultrasonic seal part and the joint part overlap, the part is paired by the joint part. Since the flat part and the gusset part are integrated, even if the concave or convex part of the ultrasonic irradiation mark or the metal foil of the convex part is torn, it is not visible from the inside of the gusset bag, and the functions such as barrier properties are lost. There is no such thing. Therefore, it is preferable that the ultrasonic seal portion and the joint portion overlap each other.

Moreover, in each said embodiment, the opening member which pours the contents to the exterior to a gusset bag may be provided.
As shown in FIG. 9, the mouth member 25 is inserted into the gusset bag 80, and is screwed into the upper part of the pouring pipe for pouring out the contents and seals the pouring outlet of the pouring pipe. It is preferable to have a cap. It is preferable that the mouth member 25 is attached by being liquid-tightly joined by heat sealing or the like in a state where the extraction pipe is sandwiched between the upper edges of the flat portion.
By providing the ultrasonic seal portion, the opening of the upper edge portion of the gusset bag can be suppressed, so that the attachment of the mouth member is facilitated.

  50, 50 ', 70, 80 ... gusset bag, 12A, 12B ... plane part, 12A', 12B '... film for plane part, 14 ... side gusset part, 14' ... side Film for gusset part, 16A ... Joint part, 18 ... Ultrasonic seal part, 19 ... Ultrasonic irradiation mark, 21 ... Laminated film, 22 ... Inner surface layer, 24 ... Outer Surface layer, 25 ... mouth member, 40 ... bottom gusset part

Claims (5)

A gusset bag comprising a pair of opposed flat portions and a gusset portion folded inward of the bag,
Among the gusset parts, it has an ultrasonic seal part in which the opposing surfaces forming the outer surface of the gusset bag are joined by ultrasonic irradiation,
Having a joint where the edge of the planar portion and the edge of the gusset portion are joined;
A gusset bag in which ultrasonic irradiation marks are formed on the back side of the surface of the gusset portion where the ultrasonic seal portion is formed.   The gusset bag according to claim 1, wherein the gusset portion is a lateral gusset portion.   The gusset bag according to claim 1, wherein the gusset portion is a bottom gusset portion.   The gusset bag as described in any one of Claims 1-3 with which the said ultrasonic seal part and the said junction part have overlapped. It is a manufacturing method of the gusset bag as described in any one of Claims 1-4,
A step of irradiating ultrasonic waves from the outside of the half-folded film for the gusset part, joining the opposing faces together, and forming an ultrasonic seal part; and
The manufacturing method of the gusset bag which has the process of joining the edge part of the film for plane parts, and the edge part of the said film for gusset parts, and forming a junction part.

Images