JP6688666B2 - Gazette bag and method of manufacturing gazette bag - Google Patents

Description

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

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

  As a method of joining the laminated films to each other to form a bag, a method of external heating in which heat is gradually transferred from the surface of the laminated film to the inside by heat conduction, radiation, and convection by a heat source outside the laminated film. There is a method by internal heating in which the inside and the outside are simultaneously heated in parallel by self-heating of the laminated film itself. External heating methods include hot plate sealing (hereinafter also simply referred to as “heat sealing”) and impulse sealing, and internal heating methods include high-frequency sealing and ultrasonic sealing.

Further, as shown in FIG. 10, the gusset bag 100 has a pair of opposed flat surface portions 102A and 102B and a pair of opposed horizontal gusset portions 104 and 104 provided on both sides of these flat surface portions 102A and 102B. In the gusset bag 100, the inner surface layer 106 is a sealant layer having heat fusion properties, and the outer surface layer 108 is a base material layer having heat resistance.
Therefore, as shown in FIG. 11, even if the open end seal portion 110 using heat sealing is applied to close the upper and lower portions of the flat surface 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 together. As a result, the upper and lower portions of the lateral gusset portion 104 are opened. In such a state, the appearance of the gusset bag 100 is inferior.
In addition, in the boundary portion between the open end seal portion 110 and the content storage portion, at the intersection 110B with the folded portion of the lateral gusset portion 104, stress is most likely to be concentrated when the lateral gusset portion 104 is open. . Therefore, if the gusset bag 100 is accidentally dropped, the bag may break from the intersection 110B where the stress is concentrated.

  Therefore, as shown in FIG. 12, a gusset bag 100 in which the opening of the lateral gusset portion 104 is closed by joining both edges 110A of the open end seal portion 110, which is the upper end of the lateral gusset portion 104, has been developed. . This improves the appearance of the gusset bag 100 and prevents the bag from being broken.

As a technique for closing the opening of such a horizontal gusset portion, in Patent Document 1, a part of the laminated film of the horizontal gusset portion is removed to provide a through hole, and the inner surface layers of the pair of flat surface portions are provided through the through hole. A gusset bag in which a pair of flat portions are integrated by joining them is disclosed.
However, in such a gusset bag, a small film piece generated by being cut off to form a through hole is mixed in the gusset bag, or the film piece is conveyed to the next step, resulting in poor sealing. It can happen.
Furthermore, although a through hole is provided in the lateral gusset portion and the through hole is blocked by the flat surface portion, the flat surface portion is uneven where the through hole is present, resulting in poor appearance.

13 is a diagram showing a lower portion 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. Is. The hatched area is an area where the laminated films forming the gusset bag 120 are joined.
When the bottom gusset portion 112 is joined to the pair of flat surface portions 102A and 102B, the outer surface layer 108 serving as the outer surface layer is formed of a heat-resistant base material layer, so that the outer surface layers 108 are not separated from each other. Normally not joined.
Therefore, when the bottom gusset portion 112 and the flat surface portions 102A and 102B are joined by cutting out a part of the edge portion of the bottom gusset portion 112, the inner surface layer 106 of the flat surface portions 102A and 102B is cut through the cutout portion 112A. The two are joined together. Thereby, the pair of flat portions 102A and 102B are integrated, the bottom is prevented from opening at the edge of the gusset bag 120, and the self-supporting function of the gusset bag 120 is exhibited.
However, in such a gusset bag 120, a small film piece generated by being cut off to form the cutout portion 112A may be mixed into the gusset bag 120, or the film piece may be conveyed to the next step. May cause poor sealing.
In this case as well, although the cutout portion 112A is blocked by the flat surface portion, the flat surface portion has irregularities where there is a through hole, resulting in poor appearance.

  Therefore, in Patent Document 2, in a self-standing 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 unseal the unsealed portion in the ship bottom sealing portion. It is formed so that it is positioned so that the front side film and the back side film of the two body films are tightly sealed at the folding trace of the band-shaped part, and the self-supporting packaging that can maintain the self-supporting property without opening the gusset at the bottom of the packaging bag. The bag is disclosed.

  However, even in the self-supporting packaging bag of Patent Document 2, when the two cutting lines are not parallel and intersect with each other, it becomes a notch, and the film piece can be cut from the bag and mixed in the gusset bag. There is a nature. Further, since the strip-shaped portion provided between the two cutting lines is bent and formed so as to be positioned at the unsealed portion inside the ship bottom sealing portion, unevenness occurs on the surface and the appearance is inferior. Further, the extension of the cutting line may cause the gusset bag to be severely torn.

  Therefore, Patent Document 3 proposes a gusset bag in which the outer surfaces of the gusset portion are joined by ultrasonic irradiation from above the heat-sealing portion after the flat portion and the end portion of the gusset portion are heat-sealed. There is.

Japanese Utility Model Laid-Open No. 2-120342 JP, 2009-90987, A International Publication No. 2015/111736

  However, in Patent Document 3, since the ultrasonic wave irradiation marks formed when ultrasonic waves are irradiated are visually recognized on the surface of the gusset bag, the appearance of the gusset bag may be impaired.

  The present invention has been made in view of such circumstances, a gazette bag having a good appearance, and preventing film pieces and scraps from being mixed in the bag in the step of closing the gazette portion, and easily. An object of the present invention is to provide a method for manufacturing a gusset bag that can close the gusset portion.

The present invention has the following aspects.
[1] A gusset bag including a pair of opposed flat parts and a gusset part that is folded inward of the bag,
Of the gusset portion, the opposing surfaces forming the outer surface of the gusset bag have ultrasonic sealing portions that are joined by ultrasonic irradiation,
A joint portion in which an edge portion of the plane portion and an edge portion of the gusset portion are joined,
A gusset bag in which ultrasonic irradiation marks are formed on the back surface side of the surface of the gusset portion on which the ultrasonic sealing 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], in which the ultrasonic seal portion and the joint portion overlap each other.
[5] The method for manufacturing a gusset bag according to any one of [1] to [4],
Irradiating ultrasonic waves from the outside of the half-folded film for the gusset portion, joining opposite surfaces to each other, and forming an ultrasonic sealing portion, and
A method for manufacturing a gusset bag, comprising a step of joining an edge portion of a film for a flat portion and an edge portion of the film for a gusset portion to form a joined portion.

  According to the present invention, a gusset bag having a good appearance, and a method of manufacturing a gusset bag that can prevent film pieces and scraps from being mixed in the bag in the step of closing the gusset portion, and can easily close the gusset portion. Can be provided.

It is a perspective view showing the upper part of the gusset bag concerning a 1st embodiment of the present invention. It is an AA sectional view of Drawing 1 which expands and shows a joined part concerning a 1st embodiment of the present invention. It is a perspective view which partially expands and shows the lateral gusset part which concerns on 1st Embodiment of this invention. It is a cross-sectional view which shows an example of the ultrasonic sealing part formation process which joins a laminated 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 joining part in the joining part formation process. It is a perspective view which shows the upper part of the 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 showing the upper part of a gusset bag in the state where the upper part of a lateral gusset part was opened. It is a perspective view which shows the upper part of the gusset bag which closed the opening of a 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.

  Hereinafter, an embodiment of a gusset bag and a method for manufacturing the gusset bag according to the present invention will be described with reference to the drawings.

<First Embodiment>
Hereinafter, the first embodiment of the present invention will be described.
The gusset bag 50 according to the first embodiment shown in FIG. 1 is provided as a pair of facing 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. And a pair of lateral gusset portions 14, 14 facing each other.

In the gusset bag 50 shown in FIG. 1, the pair of flat surface portions 12A and 12B are each formed of one laminated film, and the pair of lateral gusset portions 14 and 14 are each formed of one laminated film.
In the case of this form, as shown in FIG. 1, the joint portion 16A 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 an inner surface of the gusset bag 50, forms an inner surface layer 22 having heat-sealing properties, and an outer surface of the gusset bag 50, and has an outer surface having heat resistance. The 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.
As an example, the melting point of the resin forming the inner surface layer 22 is 170 ° C. or lower, and 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, if 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 a mixed resin thereof, an ionomer resin, ethylene. -An unstretched film composed of one or more selected from the group consisting of a vinyl acetate copolymer, an ethylene-acrylic acid copolymer, an ethylene-methyl acrylate copolymer, and an ethylene-methacrylic acid copolymer. Alternatively, a layer formed of these resins may be used.
The inner surface layer 22 preferably has a thickness of 30 to 200 μm.

The film used as the outer surface layer 24 is preferably a film having good mechanical suitability and printability. For example, a film made of a polyester-based, polyamide-based, polypropylene-based, polycarbonate-based, polyacetal-based, or other synthetic resin may be used. These films may be unstretched films or uniaxially or biaxially stretched films. The film used as the outer surface layer 24 is preferably a stretched film stretched uniaxially or biaxially from the viewpoint of printability.
Specific examples thereof include stretched plastic films such as biaxially stretched polyethylene terephthalate film, biaxially stretched polyamide film, and biaxially stretched polypropylene film. Further, synthetic paper, cellophane, paper, non-woven fabric and the like may be used as required.
As the 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 function such as gas barrier property, mechanical toughness, bending resistance, puncture resistance, impact resistance, abrasion resistance, cold resistance, heat resistance, chemical resistance, etc. it can.
As the film used for the intermediate layer, for example, aluminum, iron, copper, metal foil such as tin, polyethylene terephthalate, polyamide, polyvinyl chloride, polycarbonate, polyvinyl alcohol, a film such as saponified ethylene-vinyl acetate copolymer, Alternatively, a film coated with polyvinylidene chloride or aluminum, silicon oxide, aluminum oxide, indium oxide, tin oxide, zirconium oxide, a film deposited with an inorganic substance such as magnesium oxide, a film such as polyvinylidene chloride, or a heat insulating property Examples of the non-woven fabric and foamed film include:
The intermediate layer may be one layer or two or more layers.
The thickness of the intermediate layer may be a thickness that can satisfy the function required for the gusset bag 50, and is preferably 6 to 20 μm.
In the laminated film 21, the inner surface layer 22, the outer surface layer 24 and, if necessary, the intermediate layer are bonded together by a known method such as a dry laminating method using an adhesive or an extrusion laminating method using a thermoadhesive resin. It can be manufactured.

As shown in FIG. 2, in the lateral gusset portion 14, the opposing surfaces (hereinafter sometimes referred to as “outer surface”) of the lateral gusset portion 14 forming the outer surface of the gusset bag 50 are ultrasonic sealing portions. The ultrasonic irradiation marks 19 are formed on the back surface (hereinafter sometimes referred to as “inner surface”) of the surface on which the ultrasonic sealing 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, the outer surface layers 24 are joined at the ultrasonic sealing portion 18, and the inner surface layer 22 side. It has ultrasonic irradiation marks 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. 3. 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. Also, by being pressed by the ultrasonic sealing machine, the inner surface layer side that comes into 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 folded in half. The laminated films 21 and 21 of the overlapping lateral gusset portion 14 are deformed.

  As shown in FIG. 1, the edge portions of the flat surface portions 12A and 12B (“side edge portions” in this embodiment) and the edge portions of the lateral gusset portions 14 and 14 (“side edge portions” in this embodiment). “)” Is bonded to the inner surface layers 22, 22 of the laminated films 21, 21 by the bonding portions 16A, 16A, 16A, 16A.

Examples of the joining method of the joining portion include a joining method by heat sealing using a hot plate seal in which a heated heat seal bar is pressed against the laminated film and then a cooled cooling bar is pressed against the laminated film. Since the outer surface layer has heat resistance that does not melt at the temperature of heat sealing, it is not joined by heat sealing.
As a method of joining the joining portions, other methods such as impulse sealing may be used in addition to heat sealing. Further, when the layers forming the laminated film include a polyvinyl chloride layer or a metal foil layer, the joining can be performed by high frequency sealing. Furthermore, other joining methods other than ultrasonic sealing, such as joining with an adhesive, may be used.

As described above, in the gusset bag 50 according to the first embodiment, the outer surface layers 24, 24 of the laminated film 21 forming the lateral gusset portion 14 are joined by the ultrasonic sealing portion 18. The ultrasonic seal portion 18 is joined, for example, near the upper end and the lower end (not shown) of the lateral gusset portion 14. The range of the ultrasonic seal portion 18 according to the first embodiment is narrower than that of the joint portion 16A. That is, it is preferable that the entire ultrasonic seal portion 18 be included in the region of the joint portion 16A.
If the ultrasonic seal portion 18 is not formed, the lateral gusset portion 14 will be in a state where the outer surfaces thereof are separated from each other and open. That is, the ultrasonic sealing portion 18 closes the opening of the upper end portion and the lower end portion of the lateral gusset portion 14.

  The joining of the ultrasonic sealing portion 18 is performed by ultrasonic sealing which 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 sealing portion 18 of the gusset bag 50 according to the first embodiment, as shown in FIG. 4, the ultrasonic sealing machine 30 and the base 31 form the outer surface layer 24 of the laminated film 21, Ultrasonic sealing is performed by sandwiching the half-folded lateral gusset portion 14 with the inner surface facing outward so that the 24 faces each other. When the ultrasonic sealing is performed, the outer surface layers 24, 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, so the outer surface layers 24, 24 are rubbed with each other. Are joined together to form the ultrasonic seal portion 18.
When joining by ultrasonic sealing, scraping may occur because the two surfaces to be joined are rubbed together. However, as shown in FIG. 4, the part where the waste is generated by the joining by the ultrasonic sealing is the part where the outer surface layers 24, 24 of the laminated film 21 forming the lateral gusset part 14 are rubbed with each other. The portion where the ultrasonic sealing portion 18 is formed is outside the gusset bag 50. Therefore, even if scraps are generated by the joining by the ultrasonic seal, the scraps are not mixed in the bag because they are outside.

  In the lateral gusset portion 14, an ultrasonic irradiation mark 19 is formed on a portion of the inner surface side that is in contact with the ultrasonic sealing machine 30 (that is, the back surface side of the ultrasonic sealing portion 18). Since the flat surface portion 12A or 12B is overlapped and bonded on the ultrasonic irradiation mark 19, the ultrasonic irradiation mark 19 is not visually recognized from the outside of the gusset bag. 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 is considered that the resin of the formed film is melted to alleviate the step difference of the concave portion, and it is difficult to visually recognize the presence or absence of the ultrasonic irradiation mark 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 where the ultrasonic irradiation marks 19 are joined together, the convex portions of the ultrasonic irradiation marks 19 are crushed by the pressure of the heat seal bar at the time of forming the bonding portion, and it is not possible to visually recognize the presence or absence of the ultrasonic irradiation marks 19 from the outside of the gusset bag. Have difficulty.

  As described above, the gusset bag according to the first embodiment is formed of the pair of opposed flat surface portions and the pair of opposed lateral gusset portions that are folded inward of the bag. The gusset bag is provided with a joint portion in which the side edge portion of the flat surface portion and the side edge portion of the lateral gusset portion are joined to each other at their inner surfaces by the inner surface layers of the laminated film. Further, the gusset bag is provided with an ultrasonic sealing portion in which the opposing outer surfaces of the lateral gusset portion are outer surface layers of the laminated film and are joined by ultrasonic sealing. 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 sealing portion is formed.

  Since the opening of the gazette part is closed by the ultrasonic sealing part, the gazette bag having the ultrasonic sealing part in the gazette part suppresses the occurrence of bag breakage even if the gazette bag is accidentally dropped. . Further, the ultrasonic irradiation mark formed on the back side of the ultrasonic sealing portion can be covered with the flat surface portion, and it is difficult to visually recognize the presence or absence of the ultrasonic irradiation mark. Therefore, the gazette bag has a good appearance. be able to.

<Second Embodiment>
The second embodiment of the present invention will be described below.

FIG. 5 is a front view of the gusset bag 70 according to the second embodiment. Note that the same components in FIG. 5 as those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and description thereof is omitted.
The gusset bag 70 according to the second embodiment is formed by a pair of flat surface 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 flat surface portions 12A and 12B at the lower portion of the pair of flat surface portions 12A and 12B. The area indicated by hatching is an area where the laminated films forming the gusset bag 70 are joined.

In the lower portion of the gusset bag 70, the flat surface portions 12A and 12B and the bottom gusset portion 40 are joined to each other by the inner joint layers 42 of the laminated film.
Further, in the edge portion of the gusset bag 70 (“side edge portion” in the present embodiment), the inner surfaces of the flat portions 12A and 12B facing each other (“side edge portion” in the present embodiment) are opposed to each other. Are joined by the side joint portions 16 and 16 between the inner surface layers 22 and 22 of the laminated films 21 and 21, and the side edge portions of the flat surface portions 12A and 12B and the side edge portions of the bottom gusset portion 40 are relatively opposed to each other. The inner surfaces to be joined are the inner surface layers 22, 22 of the laminated films 21, 21 and are joined by the joining portions 16A, 16A, 16A, 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 in the lower joint portion 42. . The joining method is the same as that in the first embodiment, and thus the description is omitted.

Here, the outer surface layers of the laminated film forming the bottom gusset portion 40 are joined to each other by the ultrasonic sealing portion 18, which is the joining by ultrasonic sealing.
The ultrasonic sealing portion 18 is joined, for example, as shown in FIG. 5, near the right end or the left end of the bottom gusset portion 40.
If the ultrasonic seal portion 18 is not formed, the bottom gusset portion 40 will be in a state where the outer surfaces thereof are separated from each other and open. That is, the ultrasonic sealing portion 18 closes the opening of the right end portion or the left end portion of the bottom gusset portion 40.
The joining by ultrasonic sealing is the same as that in the first embodiment, and thus the description is omitted.

  It should be noted that the ultrasonic seal portion 18 may be provided at each of the left and right positions at the position where it overlaps with the joint portion 16A, but is not limited to this, and for example, as shown in FIG. A plurality of ultrasonic sealing 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 the pair of opposed flat surface portions and the bottom gusset portion that is folded inward of the bag. The gusset bag is provided with a joint portion in which the side edges of the flat surface portion and the side edge portion of the bottom gusset portion are joined to each other at their inner surfaces by the inner surface layers of the laminated film. Further, the gusset bag is provided with an ultrasonic sealing portion in which outer surfaces of the bottom gusset portion facing each other are outer surface layers of the laminated film and are joined by ultrasonic sealing. Further, the bottom gusset portion has ultrasonic irradiation marks on the inner surface side of the back surface side of the surface on which the ultrasonic sealing portion is formed.

  In the gusset bag having the ultrasonic sealing portion, since the opening of the gusset portion is closed by the ultrasonic sealing portion, even if the gusset bag is accidentally dropped, the occurrence of bag breakage is suppressed. Further, by closing the bottom gusset portion with the ultrasonic sealing portion, the obtained gusset bag can be provided with independence. Further, the ultrasonic irradiation mark formed on the back side of the ultrasonic sealing portion can be covered with the flat surface portion, and it is difficult to visually confirm the presence or absence of the ultrasonic irradiation mark, so that the gazette bag has a good appearance. be able to.

≪Method for manufacturing gazette bag≫
Next, a method for manufacturing the gusset bag of the present invention will be described.
The method for producing a gusset bag of the present invention is a step of irradiating ultrasonic waves from the outside of the half-folded film for the gusset portion to join the facing surfaces to each other to form an ultrasonic sealing portion (forming an ultrasonic sealing portion). Process) and the process of joining the edge portion of the film for a flat surface portion and the edge portion of the film for a gusset portion to form a bonding portion (bonding portion forming step).
Hereinafter, the details will be described by taking the gusset bag 50 of the first embodiment as an example, but the manufacturing method of 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 inside. At this time, a pair of opposing lateral gusset films 14 ', 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. By irradiating ultrasonic waves, as shown in FIG. 3, the outer surface layers 24, 24 of the lateral gusset portion film 14 ′ are joined by ultrasonic sealing to form the ultrasonic sealing portion 18. At this time, an ultrasonic irradiation mark 19 is formed on the back side of the surface on which the ultrasonic seal portion 18 is formed (that is, the inner surface layer 22 side).
The ultrasonic irradiation conditions vary depending on the laminated film used, but a frequency of 20 to 40 kHz and an irradiation time of 0.1 to 0.5 seconds are preferable.

<Joint part formation process>
As shown in FIG. 7, in the ultrasonic sealing portion forming step, a pair of opposed lateral gusset films 14 ′ and 14 ′ having the ultrasonic sealing portion 18 and the ultrasonic irradiation marks 19 are sandwiched therebetween. The pair of facing film 12A 'and 12B' are arranged so that the inner surface layers 22 of the two films 12A 'and 12B' for planar parts face inward. Further, the side edge portions 13 of the two flat surface film 12A 'and 12B' and the side edge portion 13 'of the lateral gusset portion film 14' are arranged so as to overlap each other.
Then, the inner surface layers 22 of the side edge portion 13 of the film for the flat surface portion and the side edge portion 13 ′ of the film for the horizontal gusset portion are joined along the longitudinal direction, and the joint portion is formed as shown in FIG. 16A, 16A, 16A and 16A are formed. Therefore, the ultrasonic wave irradiation mark 19 formed only on the back side of the surface on which the ultrasonic seal portion 18 is formed is covered with the flat surface film 12A ′, 12B ′. After that, a joint portion is formed on the upper edge portion or the lower edge portion to form a gusset bag 50 '.
Examples of the method for forming the joint include heat sealing, impulse sealing, high frequency sealing, bonding with an adhesive, and the like excluding ultrasonic sealing. Of these, heat sealing is preferable.
Among the methods for forming the joint, the conditions for heat sealing differ 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 gusset bag manufacturing method of the present invention, the outer surface layers of the lateral gusset portion film are bonded to each other in advance by ultrasonic sealing, so that the inner surface layers are not rubbed with each other and scraps are not generated. Therefore, it is possible to prevent film pieces and scraps from entering the bag, and it is possible to easily close the gusset portion.

  The present invention has been described above using the above-described embodiments, but the technical scope of the present invention is not limited to the scope described in the above-mentioned embodiments. Various modifications or improvements can be added to the above-described embodiments without departing from the scope of the invention, and the modified or modified embodiments 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 horizontal gusset portion may be further provided.

  Further, in each of the above-described 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 also possible to adopt a form in which a part or the whole is not included in the region of the joint or the lower joint. In this case, since the ultrasonic irradiation mark does not overlap with the joint, the step of the concave convex portion of the ultrasonic irradiation mark is not relaxed by the joint, but the flat surface is not joined to the ultrasonic irradiation mark. Since the ultrasonic wave is not radiated from the outside of the gazette bag due to the covering, it is difficult to visually confirm the presence or absence of the ultrasonic wave 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 portion of the ultrasonic irradiation mark. If 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 if the ultrasonic seal part and the joint part overlap, the part will be separated by the joint part. Since the flat part and 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 broken, it is not visible from the inside of the gusset bag and the function such as barrier property is lost. I will not be told. Therefore, it is preferable that the ultrasonic seal portion and the joint portion overlap each other.

Further, in each of the above embodiments, the gusset bag may be provided with a mouth member for pouring out the contents to the outside.
As shown in FIG. 9, the mouth member 25 is inserted into the gusset bag 80, and is screwed onto the spout pipe for pouring out the contents and the upper part of the spout pipe to seal the spout of the spout pipe. It is preferable to have a cap. It is preferable that the spout member 25 be liquid-tightly joined and attached by heat sealing or the like in a state where the spout pipe is sandwiched between the upper edge portions of the flat surface portion.
Since the opening of the upper edge portion of the gusset bag can be suppressed by providing the ultrasonic sealing portion, the mouth member can be easily attached.

  50, 50 ', 70, 80 ... Gazette bag, 12A, 12B ... Flat part, 12A', 12B '... Film for flat part, 14 ... Horizontal gusset part, 14' ... Horizontal Film for gusset part, 16A ... Joining part, 18 ... Ultrasonic sealing part, 19 ... Ultrasonic irradiation mark, 21 ... Laminated film, 22 ... Inner surface layer, 24 ... Outer Surface layer, 25 ... mouth member, 40 ... bottom gusset portion

Claims (5)

A gusset bag comprising a pair of opposed flat portions and a gusset portion folded inward of the bag,
Of the gusset portion, the opposing surfaces forming the outer surface of the gusset bag have ultrasonic sealing portions that are joined by ultrasonic irradiation,
An edge portion of the flat portion and an edge portion of the gusset portion have a heat seal, an impulse seal, a high frequency seal, or a joint portion that is joined by an adhesive ,
Ultrasonic irradiation marks are formed only on the back surface side of the surface of the gusset portion where the ultrasonic sealing portion is formed ,
The ultrasonic irradiation mark is a gusset bag covered with the flat surface portion having no ultrasonic irradiation mark .     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 according to any one of claims 1 to 3, wherein the ultrasonic sealing portion and the joint portion overlap with each other. It is a manufacturing method of the gusset bag according to any one of claims 1 to 4,
A step of irradiating ultrasonic waves from the outside of the half-folded film for the gusset portion to bond the opposing surfaces to each other to form an ultrasonic sealing portion, and then,
The gusset portion film having the ultrasonic sealing portion is sandwiched therebetween, and a pair of opposing flat portion film is arranged, and an edge portion of the flat portion film and an edge portion of the gusset portion film. A method for manufacturing a gusset bag, which includes a step of forming a joint by heat sealing, impulse sealing, high frequency sealing, or bonding with an adhesive .

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