Stand-up bag

Abstract

This disclosure aims to provide a self-standing bag that is aesthetically pleasing, environmentally friendly, can be used as an alternative to rigid containers for liquids, has low manufacturing costs, and does not cause discomfort when the body is held in the hand. [Solution] The self-standing bag 1 according to the present invention comprises a body 10 formed from a single laminated film as the body film 2, and a bottom gusset 20 into which the bottom film 3 is inserted at the lower end of the body with the open side facing downwards. The body film and the bottom film are fixed together by a bottom seal 30. The bottom seal has a bottom seal portion 31 into which the lower ends of the bottom film 3 and the lower end of the body film 2, which are opposite each other, are bonded together. The bottom film is a laminated film. The vertical seal is positioned between the left edge and the right edge. The vertical seal has a wide portion that is partially widened from the upper end of the vertical seal up to a predetermined height. The wide portion has a locking hole for suspending the self-standing bag. The self-standing bag has a spout at the upper end of the body.

Description

Technical Field

[0001] This disclosure relates to a self-standing bag.

Background Art

[0002] Conventionally, self-standing bags such as standing pouches having a body portion and a bottom portion, with the bottom portion formed in a gusset form, are known (see, for example, Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In self-standing bags like the one described in Patent Document 1, side seals are applied to the left and right edges. Because these side seals are very rigid, there were problems with usability, such as consumers feeling pain in their hands when holding the bag due to the side seals pressing against their hands. Furthermore, self-standing bags with side seals like the one described in Patent Document 1 are manufactured by folding the bottom film in half with the base film layer, such as nylon, facing inward and the sealant layer, such as polyethylene, facing outward, and then inserting the folded bottom film between the front and back body films and heat-sealing the peripheral edges of the bottom film and body film together. At this time, the opposing surfaces of the folded bottom film that face inward are made of a high-melting-point film such as nylon, and therefore are not heat-sealed to each other. This may result in unstable self-standing. Therefore, a measure is sometimes taken to expose the body film by making notches in a part of the left and right edges of the bottom film and heat-sealing the exposed body film together. However, this measure has the problem of increasing the number of manufacturing steps for the self-standing bag and generating scraps when making the notches, which increases the cost. Furthermore, the small size of the scraps made them prone to scattering, leading to problems with production efficiency. In addition, self-standing bags like those described in Patent Documents 2 and 3 lack side seals, and the bottom and body are bonded together by separate adhesive members, resulting in a complex structure. This led to problems such as reduced production efficiency and a higher likelihood of manufacturing defects such as poor adhesion. Moreover, the bag body, made of tubular film, suffered from poor rigidity, which caused it to constrict and distort, making it unstable in its ability to stand upright.

[0005] Furthermore, rigid containers such as PET bottles are widely used for liquids, including beverages. However, rigid containers are difficult to crush for disposal, and even if crushed, they create bulky waste. Therefore, there is a need for alternative containers to rigid ones.

[0006] This disclosure aims to provide a self-standing bag that is aesthetically pleasing, environmentally friendly, can be used as an alternative to rigid containers for liquids, has low manufacturing costs, and does not cause discomfort when the body is held in the hand. [Means for solving the problem]

[0007] The self-standing bag according to the present invention comprises a body film which is a single laminate film having at least a base layer and a sealant layer, with the sealant layer facing inward and a vertical seal provided, forming a cylindrical shape with the upper and lower ends open, the cylindrical shape being flattened and having a left edge and a right edge, and a bottom gusset which is inserted into the lower end of the body with the open side facing downward, the bottom film which has an open side, an upper end closed side facing the open side, a left side which connects the left end of the open side and the left end of the upper end closed side, and a right side which connects the right end of the open side and the right end of the upper end closed side, the body film and the bottom film are fixed together by a bottom seal, the bottom seal has at least a lower end seal portion which is bonded to the lower ends of the bottom film and the lower end of the body film which are facing each other, and the bottom film has at least a base layer and a sealant layer The bottom film is a film, the upper closing edge is a fold formed when the bottom film is folded in half with the base layer facing inward, the bottom seal further comprises a left seal portion in which a predetermined width region from the left edge of the bottom film is bonded to the inner surface of the body film, and a right seal portion in which a predetermined width region from the right edge of the bottom film is bonded to the inner surface of the body film, the self-standing bag has no gaps between the inner wall at the left edge of the body and the left edge of the bottom film, and between the inner wall at the right edge of the body and the right edge of the bottom film, the vertical seal is positioned between the left edge and the right edge, the vertical seal has a wide portion which is partially widened from the upper end of the vertical seal to a predetermined height, the wide portion has a locking hole for suspending the self-standing bag, and the self-standing bag has a spout at the upper end of the body. By using a laminated film for the bottom film, barrier properties can be added not only to the body but also to the bottom, thus enhancing the overall barrier properties of the bag. Furthermore, since the body film and bottom film can be made of the same material, costs can be reduced. Because the vertical seal is positioned between the left and right edges, both left and right edges become folds, eliminating the discomfort caused by the side seals touching the hand regardless of which part of the body is grasped. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide a self-standing bag that is aesthetically pleasing, environmentally friendly, has reduced manufacturing costs, and does not cause discomfort when the body is held in the hand, making it suitable as an alternative to rigid containers for liquids. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic front view showing a first example of a self-standing bag according to this embodiment. [Figure 2] This is a schematic end view of line AA in Figure 1. [Figure 3] This is a schematic front view showing a second example of a self-standing bag according to this embodiment. [Figure 4] This is a schematic front view showing a modified example of the self-standing bag in the second example according to this embodiment. [Figure 5] This is a schematic front view showing a third example of a self-standing bag according to this embodiment. [Figure 6] This is a schematic front view showing a modified example of the self-standing bag in the third example according to this embodiment. [Figure 7] Figure 6 is a schematic end view of line BB. [Figure 8] This is a schematic front view showing a fourth example of a self-standing bag according to this embodiment. [Figure 9] This is a schematic front view showing a modified example of the fourth self-standing bag according to this embodiment. [Figure 10] This diagram illustrates an example of the manufacturing process for the bottom gusset of the fourth example of a self-standing bag, with (a) showing the first step and (b) showing the second step. [Figure 11] This diagram illustrates an example of the manufacturing process for the fourth example of a self-standing bag, with (a) showing the first step, (b) the second step, (c) the third step, and (d) the fourth step. [Figure 12] Figure 3 is a schematic diagram showing the bottom gusset of the self-standing bag. [Figure 13] This is a schematic diagram showing the first modified example of the bottom gusset. [Figure 14] This is a schematic diagram showing a second modified example of the bottom gusset. [Figure 15] It is a schematic diagram showing a third modification example of the bottom gasket. [Figure 16] It is a schematic diagram showing a fourth modification example of the bottom gasket.

Mode for Carrying Out the Invention

[0010] Next, embodiments of the present invention will be shown and described in detail, but the present invention is not construed as being limited to these descriptions. As long as the effects of the present invention are achieved, the embodiments may be variously modified. Also, in this specification, for the sake of convenience, for example, when the body portion 10 is in a flat state as shown in FIG. 1, one surface is taken as the front surface, the other surface is taken as the back surface, the bottom gasket 20 is placed on the lower side, and the up, down, left, and right when viewed in plan from the front are expressed as the up, down, left, and right of the stand-up pouch 1. Here, the front surface and the back surface are not distinguished and are irrelevant to the presence or absence of the longitudinal seal portion or the printing of the body portion or the bottom gasket, and one surface of the stand-up pouch can be either the front surface or the back surface. Specifically, a pouch in which the longitudinal seal is arranged at the left edge when viewed in plan from a certain surface will become a pouch in which the longitudinal seal is arranged at the right edge when turned inside out. Also, in the drawings, for the sake of illustration and ease of understanding, the scale, dimensional ratio, thickness, etc. are exaggerated compared to the actual object.

[0011] The stand-up pouch 1 according to the present embodiment includes the stand-up pouch 1 (1A) of the first example shown in FIG. 1, the stand-up pouch 1 (1B) of the second example shown in FIGS. 3 and 4, the stand-up pouch 1 (1C) of the third example shown in FIGS. 5 and 6, and the stand-up pouch 1 (1D) of the fourth example shown in FIGS. 8 and 9. First, taking FIG. 1 as an example, the structure common to all examples will be described.

[0012] FIG. 1 is a schematic front view showing a first example of a stand-up bag according to the present embodiment. FIG. 2 is a schematic end view taken along line A-A of FIG. 1. As shown in FIG. 1 or FIG. 2, the stand-up bag 1 according to the present embodiment has a laminate film having at least a base layer 201 (shown in FIG. 2) and a sealant layer 202 (shown in FIG. 2) as a body film 2. A longitudinal seal 16 is provided with the sealant layer 202 on the inside to form a cylindrical shape with an upper end 12 and a lower end 11 open. The cylindrical shape is flattened to form a body portion 10 provided with a left edge 13 and a right edge 14, an open side 21, an upper end closing side 22 facing the open side 21, a left side 23 connecting the left end of the open side 21 and the left end of the upper end closing side 22, and a right side 24 connecting the right end of the open side 21 and the right end of the upper end closing side 22. A bottom film 3 having a bottom gusset 20 inserted into the lower end portion of the body portion 10 with the open side 21 facing downward. The body film 2 and the bottom film 3 are fixed by a bottom seal 30. The bottom seal 30 has at least a lower end seal portion 31 where the lower end portion of the bottom film 3 facing each other and the lower end portion of the body film 2 are adhered.

[0013] The stand-up bag 1 has a body portion 10 and a bottom gusset 20, and is a bag that stands up by spreading the bottom gusset 20.

[0014] The body portion 10 preferably has a substantially rectangular shape in plan view having an upper end 12, a lower end 11, a left edge 13, and a right edge 14. In this specification, the “substantially” attached before “·· shape” means the approximate outer shape without being particular about details. In addition to the shape itself, it means various deformed shapes such as a shape in which at least one of the corners of the shape is rounded or at least one of the corners is removed, or a distorted shape. For example, “substantially rectangular shape” means a rectangular shape, a shape in which at least one of the corners of the rectangle is rounded or at least one of the corners is removed, or a deformed shape in which at least one side is somewhat distorted. Also, in this specification, the surface of the body portion 10 facing the storage space 15 may be referred to as the inner surface of the body portion 10 or the inner surface of the body film 2, and the surface on the side opposite to the side facing the storage space 15 may be referred to as the outer surface of the body portion 10 or the outer surface of the body film 2.

[0015] The body portion 10 is formed by bonding the inner surfaces of both side edges of a single sheet-like body film 2 together to form a vertical seal 16 and a cylindrical shape, which is then flattened. The internal space of the body portion 10 serves as the storage space 15 for the contents. Here, "flattened" refers to a state in which, when there are no contents in the storage space 15, the inner wall surfaces of opposing body films 2 are close together or in contact, resulting in an elongated cross-sectional shape for the self-standing bag 1. Furthermore, this embodiment includes configurations in which the vertical seal 16 is positioned between the left edge 13 and the right edge 14 (as shown in Figures 1, 3, and 4), positioned on either the left edge 13 or the right edge 14 (as shown in Figures 5, 6, 8, and 9), and positioned on both the left edge 13 and the right edge 14 (not shown).

[0016] In Figure 1, the upper end 12 of the body portion 10 is shown as an open state as an example, but it may be sealed with a fitting device (not shown) or a sealing seal (not shown), or a spout (not shown) may be provided. Providing a spout at the upper end 12 of the body portion 10 makes it useful as a substitute for PET bottles. For example, from an environmental protection standpoint, many municipalities require that the cap and printed shrink label be separated from the bottle body before disposal. Consumers have to spend time disposing of PET bottles, and there is a risk of injuring their nails or fingers when peeling off the shrink label. The self-standing bag 1 according to this embodiment can be printed directly on the body portion 10, so there is no need to separate the label when disposing of it, and it can be disposed of without separating it from the spout. Therefore, it can contribute not only to easier disposal as household waste, but also to reducing working time, disposal costs, and labor costs in restaurants. The self-standing bag 1 uses less resin than PET bottles, so it can be crushed into a small size after use, making it possible to dramatically reduce the amount of waste. For example, in this embodiment, after the contents of the self-standing bag 1 are emptied, the cap is removed, and the body of the bag is folded from the bottom towards the top where the spout is located. Once folded to the bottom of the spout, the cap is tightened, maintaining a reduced pressure inside the bag. As a result, the volume of the discarded bag is about the size of a marker pen. Furthermore, the self-standing bag 1 can be washed after use and reused repeatedly, just like a PET bottle, thus reducing the environmental burden. The self-standing bag 1 can be manufactured at a lower cost than a PET bottle, so its economic benefits are immeasurable.

[0017] The body film 2, as shown in Figure 2, is a laminate film formed by bonding two or more layers together, and has at least a base layer 201 and a sealant layer 202. The base layer 201 is a layer that provides mechanical strength and printability as a packaging bag. The sealant layer 202 is a layer that has heat-sealing properties and provides bag-making processability. The materials of the base layer 201 and the sealant layer 202 are as follows: <1> ~ <29> Any of the materials exemplified here may be used, but this embodiment is not particularly limited. Of these, it is preferable to use at least one of polyamide resin or polyethylene terephthalate resin as the material for the base layer 201. It is preferable to use at least one of polyethylene or polypropylene as the material for the sealant layer 202, and it is more preferable to use linear low-density polyethylene. The number of layers for the base layer 201 and the number of layers for the sealant layer 202 may be one layer or two or more layers, respectively.

[0018] <1> High-density polyethylene (HDPE) <2> Medium-density polyethylene (MDPE) <3> Low-density polyethylene (LDPE) <4> Polypropylene (PP) <5> Polyvinylidene chloride (PVDC) <6> Polyvinyl chloride (PVC) <7> Polystyrene (PS) <8> Polyvinyl acetate (PVAc) <9> Polytetrafluoroethylene (PTFE) <10> ABS resin (acrylonitrile butadiene styrene resin) <11> AS resin (SAN) <12> Acrylic resin (PMMA) <13> Polyamide (PA) / Product Name: Nylon <14> Polyacetal (POM) <15> Polycarbonate (PC) <16> Modified polyphenylene ether (m-PPE, modified PPE, PPO) <17> Polybutylene terephthalate (PBT) <18> Polyethylene terephthalate (PET) <19> Cyclic polyolefins (COP) <20> Polyphenylene sulfide (PPS) <21> Polysulfone (PSF) <22> Polyethersulfone (PES) <23> Amorphous polyarylate (PAR) <24> Liquid crystal polymer (LCP) <25> Polyetheretherketone (PEEK) <26> Thermoplastic polyimide (PI) <27> Polyamide-imide (PAI) <28> Thermoplastic polyurethane (TPU) <29> Fluoropolymer (PTFE)

[0019] The body film 2 may have one or more intermediate layers (not shown) appropriately laminated between the base layer 201 and the sealant layer 202. The intermediate layer is, for example, a barrier layer, a printed layer, a metal foil, or a porous substrate layer such as paper. The barrier layer is a layer that prevents water vapor and / or oxygen from outside the self-standing bag 1 from permeating through the body film 2 and entering the inside of the self-standing bag 1. The barrier layer is, for example, a metal foil such as aluminum foil, a film of a material having gas barrier properties such as ethylene vinyl alcohol copolymer resin (EVOH), or a thin film having barrier properties provided on at least one surface of the base layer 201. The thin film having barrier properties is, for example, a coating film or a vapor-deposited film. The material of the coating film is not particularly limited, and for example, polyvinylidene chloride, and it can be formed by known coating methods such as roll coating, gravure coating, bar coating, spin coating, spray coating, or impregnation. Furthermore, the material of the vapor-deposited film is not particularly limited and may be, for example, aluminum, alumina, or silica, and it can be formed by known vapor deposition methods such as vacuum deposition, sputtering, ion plating, or plasma vapor deposition. The method of forming the body film 2 is not particularly limited and may be formed by bonding each layer together by known lamination methods such as extrusion lamination, dry lamination, or co-extrusion. The thickness of the body film 2 is not particularly limited, but is preferably 50 to 250 μm, and more preferably 80 to 200 μm.

[0020] The layer structure of the body film 2 is not particularly limited, but for example, it is NY / PE. In this specification, following the general method of expression in the art of packaging materials, the layer structure may be expressed by indicating the material of each layer sequentially from one surface side of the film to the other surface side, with a slash between the materials of each layer. Taking NY / PE as an example, the material of the base layer 201 is NY, the material of the sealant layer 202 is PE, and the NY and PE are laminated to each other. NY is particularly suitable for contents that are prone to oxidative degradation because it has a lower oxygen gas permeability than other materials generally used as the base layer 201. To further reduce oxygen gas permeability, NY with a barrier layer may be used as the NY.

[0021] The bottom gusset 20 closes the lower end 11 of the body 10. The bottom gusset 20 has a bag shape with one side open. When there is no contents in the storage space 15, the bottom gusset 20 is folded inside the body 10 and is flattened, so the self-standing bag 1 as a whole is flattened. However, when contents are placed in the storage space 15, the folded state of the bottom gusset 20 is unfolded and the self-standing bag 1 can stand upright stably. In this specification, when the bottom gusset 20 is in a flattened bag shape, the outer surface may be referred to as the outer surface of the bottom gusset 20 or the outer surface of the bottom film 3, and the inner surface may be referred to as the inner surface of the bottom gusset 20 or the inner surface of the bottom film 3.

[0022] The bottom gusset 20 has an open side 21, an upper closed side 22, a left side 23, and a right side 24. The bottom gusset 20 is preferably approximately rectangular in shape in plan view, as shown in Figure 1. This improves the yield of the bottom film 3 during manufacturing and allows for efficient production, thereby reducing manufacturing costs. The open side 21 is the lower end of the self-standing bag 1, and the opposing ends of the bottom film 3 are not adhered to each other. The upper closed side 22 is the part that faces the storage space 15. The left side 23 is the part that faces the inner wall of the left edge 13 of the body 10. The right side 24 is the part that faces the inner wall of the right edge 14 of the body 10. At the upper closed side 22, left side 23, and right side 24, the opposing ends of the bottom film 3 are either continuous or adhered to each other.

[0023] The material of the bottom film 3 can be any of the materials listed for the body film 2. The material of the bottom film 3 may be the same as or different from the material of the body film 2. The thickness of the bottom film 3 is preferably thinner than the thickness of the body film 2. This makes it easier to open the bottom gusset 20. For example, the thickness of the bottom film 3 is preferably 25 to 200 μm, and more preferably 40 to 180 μm.

[0024] The bottom seal 30 is a portion formed by partially bonding the inner surface of the body film 2 and the outer surface of the bottom film 3 when the bottom film 3 is inserted into the lower end of the body film 2, and includes at least a lower end seal portion 31. The lower end seal portion 31 is a portion formed by bonding the outer surface of the bottom film 3 near the open edge 21 and the outer surface of the body film 2 near the lower end 11. From the viewpoint of production efficiency, the bottom seal 30 is preferably bonded by heat sealing, but it may also be bonded using an auxiliary material such as an adhesive.

[0025] As shown in Figure 1, there may be a gap 40 between the left and right side edges 13, 14 of the body portion 10 and the left and right side edges 23, 24 of the bottom gusset 20, or there may be no gap 40 (not shown). If there is a gap 40, the lower end 11 of the body portion 10 is closed by a lower end seal portion 31 and gap seal portions 51, 52 that are continuous with the lower end seal portion 31 and whose inner surfaces are bonded together in the gap 40. If there is no gap 40, the lower end 11 of the body portion 10 is closed by the lower end seal portion 31 alone. Of these, it is more preferable to have a gap 40. The presence of a gap 40 allows the bottom film 3 to be inserted more easily into the lower end of the body film 2. This makes it possible to further increase production efficiency.

[0026] The gap 40 may be provided only between the inner wall of the left edge 13 of the body portion 10 and the bottom gusset 20, or only between the inner wall of the right edge 14 of the body portion 10 and the bottom gusset 20, or both between the inner wall of the left edge 13 of the body portion 10 and the bottom gusset 20 and the inner wall of the right edge 14 of the body portion 10 and the bottom gusset 20. The spacing of the gap 40 is not particularly limited, but is preferably 0.1 to 1.0 mm, and more preferably 0.4 to 0.7 mm.

[0027] (First example of a self-standing bag) Next, the characteristic structure of the first example of the self-standing bag 1A will be described. In the first example of the self-standing bag 1A according to this embodiment, the bottom film 3 is a laminate film having at least a base layer and a sealant layer, the upper closing edge 22 is a fold in which the bottom film 3 is folded in half with the base layer facing inward, the bottom seal 30 further has a left seal portion 32 in which a predetermined width area from the left side 23 of the bottom film 3 is bonded to the inner surface of the body film 2, and a right seal portion 33 in which a predetermined width area from the right side 24 of the bottom film 3 is bonded to the inner surface of the body film 2, and the self-standing bag 1A is between the inner wall of the left edge 13 of the body 10 and the left side 23 of the bottom film 3 and the right edge of the body 10 Preferably, the structure further includes a left gap seal portion 51 where the inner surfaces of the body film 2 are bonded together over the entire area of ​​the gap 40 on the left edge 13 side, a right gap seal portion 52 where the inner surfaces of the body film 2 are bonded together over the entire area of ​​the gap 40 on the right edge 14 side, a left connecting seal portion 53 which is connected above the left seal portion 32 and the left gap seal portion 51 and bonded together the inner surfaces of the body film 2, and a right connecting seal portion 54 which is connected above the right seal portion 33 and the right gap seal portion 52 and bonded together the inner surfaces of the body film 2.

[0028] In the first example of the self-standing bag 1A, both the body film 2 and the bottom film 3 are laminate films. The body film 2 and the bottom film 3 may have the same layer structure or different layer structures. By using the same material for both the body film 2 and the bottom film 3, costs can be reduced. The layer structure of the body film 2 is not particularly limited, but for example, it is NY / PE. The layer structure of the bottom film 3 is not particularly limited, but for example, it is NY / PE. In the first example of the self-standing bag 1A, barrier properties can be provided not only to the body 10 but also to the bottom gusset 20, thus further enhancing the overall barrier properties of the self-standing bag 1A.

[0029] In the first example of the self-standing bag 1A, the vertical seal 16 may be positioned between the left edge 13 and the right edge 14, as shown in Figures 1 and 2, or it may be positioned on the left edge 13 or the right edge 14. Of these, it is more preferable that the vertical seal 16 is positioned between the left edge 13 and the right edge 14, as shown in Figures 1 and 2. Since the left and right side edges 13 and 14 become the folds of the body film 2, the discomfort caused by the vertical seal touching the hand can be eliminated regardless of which part of the body 10 is grasped.

[0030] The bottom gusset 20 is formed by folding a single bottom film 3 in half with the base layer facing inward, and inserting it into the lower end of the body 10 so that the fold becomes the upper closing edge 22. At this time, the inner surfaces of the opposing left and right side edges 23 and 24 of the bottom film 3 are not adhered to each other. In addition, the width of the bottom film 3 is designed to be shorter than the width of the flattened cylindrical body 10, and gaps 40 are provided between the left and right side edges 13 and 14 of the body 10 and the left and right side edges 23 and 24 of the bottom film 3.

[0031] In the first example of the self-standing bag 1A, the bottom seal 30 further includes a left-side seal portion 32 and a right-side seal portion 33 in addition to the lower end seal portion 31. The left-side seal portion 32 is provided in a region of a predetermined width from the left side 23, and the right-side seal portion 33 is provided in a region of a predetermined width from the right side 24. Here, the predetermined width is not particularly limited and can be appropriately designed to be about 1 to 10 mm depending on the dimensions of the bag or the weight of the contents, for example. The bottom seal 30 may further include a left-side inclined seal portion 34 that extends diagonally between the open side 21 and the left-side seal portion 32, and a right-side inclined seal portion 35 that extends diagonally between the open side 21 and the right-side seal portion 33. The left-side inclined seal portion 34 and the right-side inclined seal portion 35 may be provided continuously between the open side 21 and the left-side seal portion 32 or the right-side seal portion 33 (as shown in Figure 1), or they may be provided intermittently or partially. Furthermore, Figure 1 shows a configuration in which the boundary lines of the left-side inclined seal portion 34 on the housing space 15 side and the boundary line of the right-side inclined seal portion 35 on the housing space 15 side are straight lines, and the left-side inclined seal portion 34, the lower end seal portion 31, and the right-side inclined seal portion 35 are connected to form an inverted trapezoid shape. However, the present invention is not limited to this, and for example, the boundary lines of the left-side inclined seal portion 34 on the housing space 15 side and the boundary line of the right-side inclined seal portion 35 on the housing space 15 side may be outwardly projecting arcs, and the left-side inclined seal portion 34, the lower end seal portion 31, and the right-side inclined seal portion 35 are connected to form an arc shape (not shown). In Figure 1, a configuration is shown in which the area enclosed by the lower end seal portion 31, the left-side seal portion 32, and the left-side inclined seal portion 34 has a non-adhesive portion 60 in which the inner surface of the opposing body film 2 and the outer surface of the bottom film 3 are not adhered. However, even in the portion that is a non-adhesive portion 60 in Figure 1, the inner surface of the opposing body film 2 and the outer surface of the bottom film 3 may be adhered.

[0032] Furthermore, the self-standing bag 1A further includes a left gap sealing portion 51 and a right gap sealing portion 52, where the inner surfaces of the body film 2 are bonded together over the entire area of ​​the left and right gaps 40, and a left connecting sealing portion 53 and a right connecting sealing portion 54, which are connected above the left gap sealing portion 51 and the right gap sealing portion 52 respectively and bonded together the inner surfaces of the body film 2. The left side 23 and the right side 24 of the bottom film 3 each have notches 28, and it is preferable that the left gap sealing portion 51 and the right gap sealing portion 52 include portions within the notches 28 where the inner surfaces of the body film are bonded together. This allows the left gap sealing portion 51 and the right gap sealing portion 52 to be bonded more firmly. The shape of the boundary line on the housing space 15 side of the left connecting seal portion 53 and the boundary line on the housing space 15 side of the right connecting seal portion 54 is shown in Figure 1 as an example where the boundary line on the housing space 15 side is a straight line, but the present invention is not limited to this, and for example, it may be an outwardly projecting arc shape (not shown). Alternatively, the boundary line on the housing space 15 side of the left connecting seal portion 53 and the boundary line on the housing space 15 side of the right connecting seal portion 54 may be an outwardly projecting arc shape, and the boundary line on the housing space 15 side of the left inclined seal portion 34 and the boundary line on the housing space 15 side of the right inclined seal portion 35 may also be an outwardly projecting arc shape, so that the left connecting seal portion 53, the left inclined seal portion 34, the lower end seal portion 31, the right inclined seal portion 35 and the right connecting seal portion 54 are connected to form an arc shape (not shown).

[0033] In the first example of the self-standing bag 1A, the inner surface of the bottom film 3 is made of a base layer, so the inner surfaces of the bottom films 3 cannot be heat-sealed together. The left and right sides 23 and 24 of the bottom film 3 are not adhered to each other, and the lower end 11 of the body 10 is not closed by simply providing the lower end seal portion 31 and the gap seal portions 51 and 52. Therefore, the lower end 11 of the body 10 is closed by providing the left side seal portion 32, the left side gap seal portion 51 and the left side connecting seal portion 53 in a continuous manner, and also by providing the right side seal portion 33, the right side gap seal portion 52 and the right side connecting seal portion 54 in a continuous manner.

[0034] (Second example of a self-standing bag) Next, with reference to Figures 3 and 4, the characteristic structure of the second example of the self-standing bag 1B will be described. In the second example of the self-standing bag 1(1B) according to this embodiment, the bottom film 3 has at least a high-melting-point sealant layer on the first surface and a low-melting-point sealant layer with a lower melting point than the high-melting-point sealant layer on the second surface opposite to the first surface, and has a flattened bag shape with the first surface facing inward and all sides except the open side closed. As shown in Figure 3 or 4, the bottom seal 30 further has a left-side inclined seal portion 34 extending diagonally between the open side 21 and the left side 23, and a right-side inclined seal portion 35 extending diagonally between the open side 21 and the right side 24, and it is preferable that the left-side inclined seal portion 34 and the right-side inclined seal portion 35 are portions that bond the inner surfaces of the opposing body film 2 and the bottom film 3.

[0035] As will be explained later, the second example of the self-standing bag 1B differs from the first example of the self-standing bag 1A in that the layer structure of the bottom film 3 has heat-sealing properties on the inner surface of the bottom film 3. Therefore, one of the sides of the bottom film 3 other than the open side 21, namely the upper closing side 22 and the left and right side sides 23 and 24, can be folded, and the remaining sides can be sealed by heat bonding the opposing bottom film 3s together. As a result, the lower end 11 of the body portion 10 is sealed only by the lower end seal portion 31 and the gap seal portion 50. Consequently, the area where the inner surfaces of the body film 2 are bonded together at the left and right side edges 13 and 14 of the body portion 10 is limited to the area at the lower end of the body portion 10, thus eliminating the discomfort caused by the side seals touching the hand when gripping the part of the body portion 10 that contains the bottom gusset 20.

[0036] In the bottom film 3, only the open edges 21 are in a non-adherent state between the inner surfaces of the bottom film 3 facing each other, and the upper closed edge 22, left edge 23, and right edge 24 are closed. In Figure 3, as an example, the bottom film 3 is a single sheet-like film, with the fold of the single sheet-like film being the upper closed edge 22, the portion where the inner surfaces of the sheet-like film are not adhered to each other at the edge opposite the fold being the open edge 21, and the portions where the inner surfaces of the sheet-like film are adhered to each other at the edges extending from both ends of the fold being the left edge 23 and right edge 24. However, the present invention is not limited to this.

[0037] In the second example of the self-standing bag 1B, the material of the bottom film 3 is a laminated film with sealant layers arranged on the front and back sides, each having a different melting point. In this laminated film, the melting point of the sealant layer on the second surface (outside, on the side of the body film 2) is lower than that of the sealant layer on the first surface (inside, opposite to the side of the body film 2). This allows the opposing inner surfaces of the bottom film 3 to be heat-bonded together, while preventing the inner surfaces of the bottom film 3 from bonding together when forming the lower end seal portion 31, thus enabling the efficient manufacture of the self-standing bag 1. The materials of the low-melting-point sealant layer and the high-melting-point sealant layer can be appropriately combined from the materials exemplified as the material of the body film 2 that can be used as sealant layers, so as to achieve the desired difference in melting points between the front and back sides. There are no particular limitations, and for example, it is preferable to appropriately select from PE and PP. The melting point of the low-melting-point sealant layer is not particularly limited, but is preferably 70 to 100°C, and more preferably 80 to 90°C. The melting point of the high-melting-point sealant layer is not particularly limited, but is preferably 90 to 130°C, and more preferably 100 to 120°C. The difference in melting points between the high-melting-point sealant layer and the low-melting-point sealant layer is preferably 10 to 50°C, and more preferably 20 to 40°C.

[0038] In the second example of the self-standing bag 1B, the bottom film 3 is preferably a laminated film in which a base layer is laminated between a high-melting-point sealant layer and a low-melting-point sealant layer. It is more preferable that the base layer has a barrier layer. This allows barrier properties to be provided not only to the body portion 10 but also to the bottom gusset 20, thereby further enhancing the overall barrier properties of the self-standing bag 1. The material of the base layer is not particularly limited and can be appropriately selected from, for example, the materials exemplified as the material of the body portion film 2. The layer configuration of the bottom film 3 is not particularly limited, but for example, it is PE / NY / PE.

[0039] In the second example of the self-standing bag 1B, the bottom seal 30 further includes a left-side inclined seal portion 34 and a right-side inclined seal portion 35 in addition to the lower end seal portion 31. The left-side inclined seal portion 34 and the right-side inclined seal portion 35 may be provided continuously between the open edge 21 and the left and right side edges 23, 24 (as shown in Figure 1), or they may be provided intermittently or partially. Furthermore, Figure 3 shows a configuration in which the boundary line of the left-side inclined seal portion 34 on the storage space 15 side and the boundary line of the right-side inclined seal portion 35 on the storage space 15 side are straight lines, and the left-side inclined seal portion 34, the lower end seal portion 31 and the right-side inclined seal portion 35 are connected to form an inverted trapezoid shape. However, the present invention is not limited to this, and for example, the boundary line of the left-side inclined seal portion 34 on the storage space 15 side and the boundary line of the right-side inclined seal portion 35 on the storage space 15 side may be an outwardly projecting arc shape, and the left-side inclined seal portion 34, the lower end seal portion 31 and the right-side inclined seal portion 35 are connected to form an arc shape (not shown).

[0040] In the second example of the self-standing bag 1B, the vertical seal 16 is positioned between the left edge 13 and the right edge 14, as shown in Figure 3 or Figure 4. The vertical seal 16 is positioned on the outside of the body film 2 in the thickness direction of the storage space 15. As a result, both the left and right side edges 13 and 14 become folds in the body film 2, eliminating the discomfort caused by the side seal touching the hand regardless of which part of the body 10 is grasped. The position of the vertical seal 16 may be closer to the right edge 14 between the left edge 13 and the right edge 14, as shown in Figure 3, or in the center between the left edge 13 and the right edge 14, as shown in Figure 4, or closer to the left edge 13 between the left edge 13 and the right edge 14 (not shown). In addition, the shape of the vertical seal 16 is generally a roughly rectangular shape as shown in Figure 3, but it may be an irregular shape as shown in Figure 4. Also, as shown in Figure 4, the vertical seal 16 may be provided with a locking hole 17 to allow it to be hung.

[0041] (Third example of a self-standing bag) Next, referring to Figures 5 to 7, the characteristic structure of the third example of the self-standing bag 1C will be described. The third example of the self-standing bag 1C has the same configuration as the second example of the self-standing bag 1B, except for the position of the vertical seal 16. Therefore, the explanation of the common components will be omitted.

[0042] In the third example of the self-standing bag 1C, the vertical seal 16 is located on the left edge 13 or the right edge 14. In Figures 5 and 6, the vertical seal 16 is located on the right edge 14, but the present invention is not limited to this and may be located on the left edge 13. By using the vertical seal 16 as a side seal, the following effects can be obtained. For example, the thickness can be made uniform around the entire circumference of the opening edge of the upper end 12 of the body portion 10 that communicates with the storage space 15, thereby preventing pinholes in the bottom seal 30 and the seal that closes the upper end 12 of the body portion 10, and allowing the bag to be sealed more reliably. In addition, since the side edge on the side without the vertical seal 16 (the left edge 13 in Figures 5 and 6) of the left and right side edges 13, 14 becomes the fold of the body film 2, the discomfort caused by the side seal touching the hand can be eliminated by gripping the self-standing bag 1 around this part.

[0043] In the third example of the self-standing bag 1C, the vertical seal 16 is preferably free from the outer surface of the body 10, as shown in Figure 5, and has a locking hole 17 for suspending the self-standing bag 1. The locking hole 17 is a through hole provided in the vertical seal 16, and its shape is not particularly limited. By attaching fasteners (not shown), such as carabiners or hooks, to the locking hole 17, portability can be further improved. For this reason, it is suitable for use in outdoor activities or exercise where portability is required. In addition, although the vertical seal 16 is generally approximately rectangular in shape, it may be made into an irregular shape, for example, by providing a partially wider section as shown in Figure 5, or it may be made wider than usual to facilitate the provision of the locking hole 17.

[0044] Furthermore, in the third example of the self-standing bag 1C, it is preferable that the vertical seal 16 is fixed to the outer surface of the body portion 10 in a state where it is folded back along the outer surface of the body portion 10, as shown in Figures 6 and 7. Since the left and right side edges 13 and 14 become the folds of the body portion film 2, the discomfort caused by the side seals touching the hand can be eliminated regardless of which part of the body portion 10 is grasped. The method of fixing the vertical seal 16 to the outer surface of the body portion 10 is not particularly limited, and for example, it may be bonded with a hot melt adhesive.

[0045] (Fourth example of a self-standing bag) Next, with reference to Figures 8 to 11, the characteristic structure of the fourth example of the self-standing bag 1D will be described. The fourth example of the self-standing bag 1D has the same configuration as the third example of the self-standing bag 1C, except that the lower end of the vertical seal 16 includes the bottom film 3 and the body film 2 and the bottom film 3 are integrally bonded together. Therefore, the explanation of the common components will be omitted.

[0046] In the fourth example of the self-standing bag 1D, the bottom film 3 has at least a high-melting-point sealant layer on the first surface 3a (shown in Figure 10) and a low-melting-point sealant layer with a lower melting point than the high-melting-point sealant layer on the second surface 3b (shown in Figure 10) opposite to the first surface 3a, the left side edge 23 is a fold where the bottom film 3 is folded with the first surface facing inward, as shown in Figure 8 or Figure 9, the vertical seal 16 is positioned on the right edge 14 and has a lower end portion 16a which is integrally bonded with the body film 2 with the right side edge 24 of the bottom film 3 sandwiched between the body film 2, and preferably the lower end portion 16a of the vertical seal 16 has an adhesive portion between the inner surface of the body film 2 and the bottom film 3, an adhesive portion between the bottom film 3 and the body film 2, and an adhesive portion between the bottom film 3 and the inner surface of the body film 2, along the thickness direction of the body film 2 and the bottom film 3.

[0047] In the fourth example of the self-standing bag 1D, the position of the vertical seal 16 and the side edge of the bottom film 3 included in the lower end 16a of the vertical seal 16 are both shown as being on the right side. However, as mentioned earlier, left and right are merely convenient terms. If the self-standing bag 1D in Figures 8 and 9 is viewed from the opposite side of the illustrated surface, the position of the vertical seal 16 will be the left edge of the body portion 10, and the side edge of the bottom film 3 included in the lower end 16a of the vertical seal 16 will be the left side. Therefore, in the fourth example of the self-standing bag 1D, the left and right terms refer to the left and right when the self-standing bag 1D is viewed from the plan such that the vertical seal 16 is on the right side. In the fourth example of the self-standing bag 1D, the vertical seal 16 becomes a side seal, similar to the third example of the self-standing bag 1C (shown in Figure 5 or 6), and thus achieves the effects obtained by making the vertical seal 16 a side seal.

[0048] In the fourth example of the self-standing bag 1D, it is sufficient that at least the upper closing edge 22 and the left side edge 23 are closed. As an example, Figures 8 and 9 show a configuration in which a single bottom film 3 is folded over, with the left side edge 23 being the fold, and the inner surfaces of the bottom film 3 are bonded together at the edge extending from one end of the left side edge 23 to form the upper closing edge 22. However, the present invention is not limited to this. For example, the inner surfaces of the bottom film 3 may be bonded together at the left side edge 23 as shown in Figures 8 and 9. The configuration in which the inner surfaces of the bottom film 3 are bonded together includes a configuration in which a single bottom film 3 is heat-sealed from above the fold to bond the bottom film 3 facing each other in a predetermined width area from the fold, and a configuration in which two bottom film 3 are overlapped with their first surfaces facing inward and their edges bonded together at a predetermined width.

[0049] In the fourth example, the self-standing bag 1D, as shown in Figure 8, preferably has a vertical seal 16 that is free from the outer surface of the body portion 10 and has a locking hole 17 for suspending the self-standing bag 1. The configuration and effect of the locking hole 17 are the same as those of the third example, the self-standing bag 1C, shown in Figure 5.

[0050] The end face crossing the body portion 10 in Figure 9 is as shown in the end view in Figure 7. In the fourth example of the self-standing bag 1D, it is preferable that the vertical seal 16 is fixed to the outer surface of the body portion 10 in a state where it is folded back along the outer surface of the body portion 10, as shown in Figure 8. The fixing of the vertical seal 16 and its effect are the same as in the third example of the self-standing bag 1C shown in Figure 6.

[0051] Referring to Figures 10 and 11, an example of the manufacturing process for the fourth example of the self-standing bag 1D will be described. First, as shown in Figure 10(a), a single sheet-like bottom film 3 is folded in half with the first surface 3a, which is made of a high-melting-point sealant layer, facing inward to form a closed left side 23 formed by the fold. Next, as shown in Figure 10(b), the inner surfaces of opposing bottom films 3 are bonded together at the edge extending from one end of the left side 23 to form the upper closed side 22. At this time, the inner surfaces of the bottom films 3 on the right side 24 may be left unbonded or bonded.

[0052] As shown in Figure 11(a), the bottom film 3 obtained in Figure 10(b) is inserted into the lower end of a single sheet-like body film 2 that has been folded in half (first step). At this time, in the part where the lower end 16a of the vertical seal 16 is formed, the right side 24 made up of two overlapping bottom films 3 is sandwiched between the inner surfaces of the two overlapping body films 2. Also, in Figure 11(a), as an example, the edge on the open side 21 of the bottom film 3 is positioned to extend outward from the lower end edge of the body film 2, but the present invention is not limited to this, and the edge on the open side 21 may be positioned inside the lower end edge of the body film 2 (not shown), or the edge on the open side 21 may be positioned to coincide with the lower end edge of the body film 2 (not shown). Next, as shown in Figure 11(b), the vertical seal 16 is formed (second step). The vertical seal is preferably formed by heat sealing, and the method of formation is not particularly limited, but may be, for example, heat sealing, ultrasonic sealing, high-frequency sealing, spot sealing, impulse sealing, or laser bonding. At this time, at the lower end 16a of the vertical seal 16, a heat-bonded portion is formed between the inner surface of the body film 2 and the bottom film 3, a heat-bonded portion is formed between the bottom films 3 and each other, and a heat-bonded portion is formed between the bottom film 3 and the inner surface of the body film 2, so that the two body films 2 and the two bottom films 3 are heat-bonded together as a single unit. In the portion of the vertical seal 16 other than the lower end 16a, the inner surfaces of the two body films are heat-bonded to each other. Next, as shown in Figure 11(c), various bottom seals 30 (31, 34, 35) and gap seal portions 50 if there are gaps 40 are formed, and the lower end 11 of the body 10 is closed (third step). The various bottom seals 30 (31, 34, 35) and gap seal portions 50 may all be formed simultaneously, or they may be formed sequentially. In the process shown in Figure 11(a), if the edge of the bottom film 3 on the open side 21 extends outward from the lower edge of the body film 2, the lower seal portion 31 and gap seal portion 50 formed in Figure 11(c) are cut at an appropriate position, for example, the position of the dashed line L (shown in Figure 11(c)) (fourth step).As a result, the lower end of the body film 2 and the open edge 21 of the bottom film 3 coincide, and the coincided lower end of the body film 2 and the open edge 21 of the bottom film 3 are bonded together around the entire circumference. This creates a highly rigid bonded area between the lower end of the body film 2 and the open edge 21 of the bottom film 3 with respect to the contact surface of the self-standing bag 1, allowing the self-standing bag 1 to stand stably on its own.

[0053] Up to this point, we have described the self-standing bag 1 according to this embodiment with specific examples, but the present invention is not limited to these descriptions. Various modifications of the embodiment are possible as long as the effects of the present invention are achieved.

[0054] For example, in the first example of the self-standing bag 1A shown in Figure 1, the vertical seal 16 may be provided with a locking hole 17 to allow it to be hung, as shown in Figure 4; the vertical seal 16 may be placed on the left edge 13 or the right edge 14 and the vertical seal 16 may be provided with a locking hole 17 to allow it to be hung, as shown in Figure 5; or the vertical seal 16 may be folded back along the outer surface of the body 10 and fixed to the outer surface of the body 10, as shown in Figures 6 and 7.

[0055] In the second example of the self-standing bag 1B and the third example of the self-standing bag 1C shown in Figures 3 to 6, as shown in Figure 12, the bottom gusset 20 is formed by folding a single sheet-like bottom film 3 (3C) in half, with the fold forming the upper closing edge 22. The left side 23 and right side 24 are the parts that are closed by bonding the inner surfaces of the bottom film 3 together at both ends of the fold. However, variations such as those shown in Figures 13 to 16 may also be used.

[0056] As shown in Figure 13, the bottom film 3(3A) is a tubular film with no seams in the circumferential direction and has a cylindrical shape with both ends open. The open side 21 is the portion where two opposing bottom film 3(3A) pieces are not adhered to each other at one end of the cylindrical shape of the bottom film 3(3A). The upper closed side 22 is the portion where two opposing bottom film 3(3A) pieces are adhered to each other at the other end of the cylindrical shape of the bottom film 3(3A) to close the area. Preferably, the left side 23 and the right side 24 are folds formed by flattening the cylindrical shape of the bottom film 3(3A). A tubular film with no seams in the circumferential direction as shown in Figure 13 can be formed, for example, by inflation molding. The bottom film 3(3A) can be manufactured in a simple process such as preparing a roll of cylindrical film in advance and then heat-sealing and slitting the film at predetermined intervals while unwinding it, thus reducing manufacturing costs.

[0057] Furthermore, as shown in Figure 14, the bottom film 3(3B) is a single sheet-like film, and the sheet-like film is glued together from the back to form a cylindrical shape. The other end of the cylindrical shape of the bottom film 3(3B) is bonded together to form the upper end closing edge 22, and the folds formed by flattening the cylindrical shape of the bottom film 3(3B) may be the left side 23 and the right side 24.

[0058] The bottom film 3 (3D), as shown in Figure 15, may consist of two sheet-like films. The two sheet-like films may be superimposed, with one edge of the periphery leaving the inner surfaces of the sheet-like films unglued, forming an open edge 21. The remaining edge of the periphery may be bonded together to close the inner surfaces of the sheet-like films, forming the upper closed edge 22, left edge 23, and right edge 24, respectively.

[0059] The bottom film 3 (3E) may be a single sheet-like film, where the fold of the single sheet-like film is made into either the left side 23 or the right side 24 (right side 24 in Figure 7), the portion where the inner surfaces of the bottom film are bonded together at the edge opposite the fold is the other of the left side 23 or the right side 24 (left side 23 in Figure 7), the portion where the inner surfaces of the sheet-like film are bonded together at the edge extending from one end of the fold is the upper closed edge 22, and the portion where the inner surfaces of the sheet-like film are not bonded together at the edge extending from the other end of the fold is the open edge 21.

[0060] In the fourth example of the self-standing bag 1D shown in Figures 8 and 9, the bottom gusset 20 may be formed using the bottom film 3 shown in Figures 12 to 16. [Explanation of Symbols]

[0061] 1 (1A, 1B, 1C, 1D) Self-standing bag 2. Body film 3(3A,3B,3C,3D,3E) Bottom film 3a 1st page 3b 2nd side 10 Torso 11 Bottom end 12 Top 13 Left side edge 14 Right edge 15 Containment space 16 vertical stickers 16a Lower end of vertical seal 17 Locking hole 20 Bottom gusset 21 Open edges 22 Upper end closed edge 23 Left side 24 Right side 28 Notches 30 Bottom seal 31 Lower end sealing portion 32 Left side seal section 33 Right side seal section 34 Left-side slanted seal section 35 Right side inclined seal part 40 gaps 50 Gap sealing section 51 Left side gap sealing section 52 Right side gap sealing section 53 Left side connecting seal section 54 Right-side connecting seal section 60 Non-bonded area 201 Base Layer 202 Sealant layer

Claims

[Claim 1] A single laminate film having at least a base layer and a sealant layer as the body film is formed into a cylindrical shape with the sealant layer facing inward and a vertical seal provided, with the upper and lower ends open, and the cylindrical shape is flattened and a left edge and a right edge are provided for the body, A self-standing bag comprising a bottom gusset in which a bottom film is inserted into the lower end of the body with the open side facing downwards, the bottom film having an open side, an upper closing side opposite to the open side, a left side connecting the left end of the open side and the left end of the upper closing side, and a right side connecting the right end of the open side and the right end of the upper closing side, The body film and the bottom film are fixed together with a bottom seal. The bottom seal has at least a bottom seal portion in which the lower ends of the bottom film and the lower end of the body film, which are facing each other, are bonded together. The bottom film is a laminate film having at least a base layer and a sealant layer. The upper closing edge is a fold formed when the bottom film is folded in half with the base layer facing inward. The bottom seal further comprises a left-side sealing portion in which a predetermined width region from the left side of the bottom film is bonded to the inner surface of the body film, and a right-side sealing portion in which a predetermined width region from the right side of the bottom film is bonded to the inner surface of the body film. The self-standing bag has no gaps between the inner wall at the left edge of the body and the left side of the bottom film, and no gaps between the inner wall at the right edge of the body and the right side of the bottom film. The aforementioned vertical seal is positioned between the left edge and the right edge, The vertical seal has a widened portion that extends from the upper end of the vertical seal to a predetermined height, and the widened portion has a locking hole for suspending the self-standing bag. The self-standing bag is characterized by having a spout at the upper end of the body.

Images