JP2006298438A - Self-standing bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-standing bag of a standing pouch type with a bottom part formed by a gusset type, which is furthermore excellent in self-standing properties, which keeps the cut face of the bottom part not tightly stuck even when the thickness of a sealant layer of the bag is thick, and which is also excellent in suitability to a filling and sealing machine. <P>SOLUTION: The self-standing bag has a constitution manufactured by a manufacturing method wherein the self-standing bag is formed by a standing pouch type with the bottom part provided with the gusset part 4, after each part of the bag is heat-sealed, when the surroundings are trimed, a horizontal straight line part 13 is provided at the central part of the lower side end part of the bottom part gusset part 4 of the bag, and oblique cut parts 14a and 14b obliquely upward cut outward from the inside on both sides, and at least horizontal straight line part 13 is cut in the direction reverse to the flowing direction of the film by a blade with the blade edge stood and with a thin thickness, or a roll cutter. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a self-supporting bag, and more specifically, in a standing pouch-type self-supporting bag in which a bottom portion is formed in a gusset form to provide self-supporting characteristics, while further improving the self-supporting stability and filling the contents with a filling sealer The present invention relates to a self-supporting bag in which there is no adhesion between the front and rear films on the cut surface at the bottom of the bottom gusset when sealing, and the bottom can be easily opened and closed to fill and seal the contents.

Conventionally, as a self-supporting bag, a standing pouch-type self-supporting bag that is formed with a gusseted bottom and has self-supporting properties is not only self-supporting, but also has some features as a three-dimensional container, and has an excellent appearance. In addition to contents such as solids, granules and powders, liquid contents are widely used for sealed packaging of a wide range of contents.
Among these, especially when liquid contents are sealed and packaged, it is necessary to further stabilize the self-supporting property of the bag, to prevent leakage, and to provide strength against impacts such as dropping. Various measures have been taken to improve the shape of the bottom of the bag and the like, and for example, a relatively thick linear low-density polyethylene having a thickness of 80 μm or more has been used for the sealant layer of the laminated film of the bag.

  As a self-supporting bag that further stabilizes the self-supporting ability of the standing pouch-type self-supporting bag, for example, (1) A protrusion formed by extending the front and rear films of the gusset portion at the lower ends of both front and rear wall surfaces of the bag A self-supporting bag having a configuration provided, and a self-supporting bag having a configuration in which the protruding portion is provided in a shape protruding in an arc shape from the entire lower side of the bag, and the protruding portion has a central portion of the lower side of the bag. A self-supporting bag having a configuration in which the tip of the projecting portion is formed in an arc shape in a part of the region, and the projecting portion is tab-shaped at the center of the lower side of the bag or at a plurality of locations on the lower side There is a self-supporting bag having a configuration provided in a shape (see Patent Document 1).

(2) A self-supporting bag having a structure in which wavy irregularities in the vertical direction are formed on a heat-sealing part of a ship bottom that heat-seals a lower gusset part of a standing pouch-type self-supporting bag, and (1) Similar to the described self-supporting bag, a protrusion formed by extending the front and rear films of the gusset portion is provided at the lower ends of the front and rear wall surfaces of the bag, and the vertical wavy irregularities are also molded on the protrusion. There is a self-supporting bag having a configuration (see Patent Document 2).
Japanese Patent Laid-Open No. 2001-72080 (pages 2 to 3, FIGS. 1 to 4) Japanese Patent Laid-Open No. 2001-72081 (pages 2 to 3, FIGS. 1 to 5)

According to the inventions described in Patent Documents 1 and 2, in any case, the self-supporting ability of the standing pouch-type self-supporting bag can be further stabilized. However, even in such a self-supporting bag, when the liquid contents are hermetically packaged, as described above, a relatively thick linear low density polyethylene (L / LDPE) or the like is used as a sealant layer of the laminated film of the bag. In addition, since the protrusions are provided at the lower ends of the front and rear wall surfaces of the bag, in the bag making process of the bag, after heat-sealing the lower gusset portion and side portions of the bag, When trimming the periphery, at least the lower side of the bag could not be cut in a straight line, and was inevitably cut by a punching-type punching means such as a die set.
For this reason, especially in the gusset part at the bottom of the bag where the overlap of the film is large and the total thickness of the sealant layer is large, when the lower end is cut, the resin of the sealant layer mainly follows the cutting blade of the push-off method. The gusset portion is stretched and the hook-shaped portions before and after the gusset portion are temporarily attached to each other at the cut surface, and the bottom opening of the bag deteriorates when filling the contents, and the bag filling machine suitability is impaired. was there.

  The present invention has been made to solve such problems, and the problem is that a standing pouch type self-supporting bag having a bottom portion formed in a gusset type to provide self-supporting stability. In addition, there is no adhesion between the front and rear films on the cut surface at the bottom of the bottom gusset, and when filling the contents with a filling and sealing machine, the bottom of the bag can be easily opened back and forth without causing troubles in filling the contents. It is to provide self-supporting bags that can be made with high productivity.

The above problems can be solved by the following present invention.
That is, in the invention described in claim 1, at least the bottom portion of the bag is formed in a form having a gusset portion formed by inserting a bottom film into the inside between the lower portions of the front and back wall films, and the gusset portion is It is formed by heat-sealing with a bottom-bottom-shaped sealing pattern in which the inner central part is low and both sides gradually increase toward the side part of the bag, and the trunk part is formed on the left and right edges of the front and rear wall films. It is formed by heat sealing at the side seal part, the center part of the lower end part of the bottom gusset part is cut by a horizontal straight line, and both sides thereof are cut obliquely upward from the inside to the outside A self-supporting bag, after heat-sealing each part of the self-supporting bag, when trimming the periphery of the bag, at least a horizontal straight portion at the center of the lower end portion of the bottom gusset portion, It consists self-standing bag, characterized in that it is produced by the method of cutting a thin blade or roll cutter thick like a standing edge in the opposite direction with.

In the present invention, a self-standing bag is made in a form in which one or two rows are butted in a form in which the bags are connected adjacently in the horizontal direction, like a normal standing pouch.
The cutting method of the portion other than the horizontal straight portion at the center of the lower end portion of the bottom gusset portion when trimming the periphery of the bag is not particularly limited, and can be a punching-type punching means such as a die set. The whole part other than the horizontal straight part may be cut, and when the side part of the bag is a straight line, this part can be cut by the shear cut method.

  Moreover, the length of the said horizontal straight part should just be 30% or more with respect to the length of the full width of a bag, and it is preferable that it is the length of the range of 30-80%. If the length of the horizontal straight portion is less than 30%, the bottom opening of the bag tends to deteriorate, and if it exceeds 80%, the width of the portion cut obliquely upward on both sides is reduced and the bag Since it becomes difficult to obtain the effect of improving the self-supporting stability, it is not preferable.

  As described above, even the horizontal straight line portion at the center of the lower end of the bottom gusset portion of the self-supporting bag can be cut with a thin blade or roll cutter with the blade edge raised in the direction opposite to the film flow direction. For example, the film before and after this part is not temporarily attached to the cut surface, and when the bag is filled with the filling and sealing machine, the central part of the lower end of the gusset part easily spreads back and forth. Therefore, even if the part cut obliquely upward from the inside to the outside on both sides is cut and temporarily attached by the push-off method, it gradually spreads from the center to the sides on both sides. A large resistance force does not work, the entire bottom part is easily spread back and forth, and the suitability of the self-supporting bag filling and sealing machine is not impaired.

  The invention described in claim 2 is the self-standing bag according to claim 1, wherein a spout portion having a narrow width is provided by a heat seal pattern at an upper corner portion of the self-standing bag.

  The configuration as described above is suitable for the case where the contents filled in the self-supporting bag are fluid contents such as liquid and are used by being transferred to another container having a small diameter such as a bottle at the time of use. The width, shape, orientation, and the like of the spout port can be appropriately determined according to the viscosity of the contents and the size of the mouth of the container to be transferred.

  According to the invention described in claim 1, at least the bottom portion of the bag is formed in a form having a gusset portion formed by inserting a bottom film inwardly between the lower portions of the front and rear wall films, and the gusset portion is It is formed by heat-sealing with a bottom-bottom-shaped sealing pattern in which the inner central part is low and both sides gradually increase toward the side part of the bag, and the trunk part is formed on the left and right edges of the front and rear wall films. It is formed by heat sealing at the side seal part, the center part of the lower end part of the bottom gusset part is cut by a horizontal straight line, and both sides thereof are cut obliquely upward from the inside to the outside A self-supporting bag, after heat-sealing each part of the self-supporting bag, when trimming the periphery of the bag, at least a horizontal straight portion at the center of the lower end portion of the bottom gusset portion, Since the self-supporting bag is manufactured by a manufacturing method in which the blade edge is raised in the opposite direction and cut with a thin blade or a roll cutter, at least the horizontal straight portion has a relatively large thickness of the sealant layer of the laminated film of the bag. Even when it is thick, as described above, the resin of the sealant layer is stretched by the cutting blade, and the front and rear films are not temporarily attached to each other at the cut surface, and the bottom opening of the bag is good and the content filling seal A self-supporting bag excellent in machine suitability can be obtained.

  As for the self-supporting property of the self-supporting bag, the bottom portion of the bag is formed in the form having the gusset portion, the lower end portion of the gusset portion is cut by a horizontal straight line, and both sides thereof are inside. Since the structure is cut diagonally upward from the outside, the contents of the self-supporting bag are filled and sealed, and when the self-supporting bag is placed on a flat surface, the outer periphery of the bottom of the bag The tip of the leg by the heat-sealed part is in contact with the base surface even in the center part of the front and back of the bag, which is particularly prone to lift. The property is further improved.

  According to the invention described in claim 2, in the structure of the self-supporting bag of the invention described in claim 1, as a structure in which a spout portion having a narrow width is provided by a heat seal pattern at an upper corner portion of the self-supporting bag. Therefore, in addition to the function and effect of the invention described in claim 1, the content filled in the self-supporting bag is, for example, a liquid content, and when used, it is transferred to another container such as a bottle. Even when used, the contents can be safely and easily transferred without spilling out.

Embodiments such as a film used for manufacturing the self-supporting bag of the present invention, a configuration of the self-supporting bag, and a manufacturing method thereof will be described below with reference to some drawings.
First, the film used for the production of the self-supporting bag of the present invention is mainly a laminated film mainly made of plastic, but is not particularly limited, and any known laminated film used in various pouches is used. it can.
In a simple structure, a laminated film having a structure in which a sealant layer is laminated on a base film layer is used. However, the contents filled in the bag, the amount thereof, or the use conditions such as the presence or absence of heat treatment after filling the contents Furthermore, depending on the required performance such as water vapor and other gas barrier properties, light shielding properties and various mechanical strengths, water vapor and other gas barrier layers between the base film layer and the sealant layer, light shielding, etc. A laminated film having a structure in which a layer, a strength improving layer, and the like are laminated can be used.
The above-mentioned base film layer, water vapor and other gas barrier layers, light shielding layer, strength improving layer, sealant layer and the like may each be formed as a single layer, or may be formed by laminating a plurality of layers. .

Examples of the base film layer include biaxially stretched films of polyester such as polyethylene terephthalate and polyethylene naphthalate, as well as biaxially stretched films of polyamide such as nylon 6, nylon 66, MXD6 (polymetaxylylene adipamide), and A biaxially stretched polypropylene film or the like can be preferably used.
These may be used singly or may be used by combining a plurality.

  Examples of the gas barrier layer include films of saponified ethylene / vinyl acetate copolymer (EVOH), polyvinylidene chloride (PVDC), MXD6, polyacrylonitrile (PAN), aluminum foil, silica, alumina, oxidation Biaxially stretched nylon film (ON film), biaxially stretched polyethylene with a coating layer of inorganic oxides such as zinc, magnesium oxide, ITO, or metals such as aluminum, or coating layers such as PVDC and polyvinyl alcohol (PVA) A terephthalate film (PET film), a biaxially stretched polypropylene film (OPP film), etc. can be used.

The inorganic oxide or metal vapor-deposited layer can be formed by being deposited on the base film so as to have a thickness of about 200 to 1200 mm by means of vapor deposition, sputtering, ion plating or the like.
The inorganic oxide vapor-deposited layer may be formed of a single layer, but by forming it with a plurality of layers, a more excellent gas barrier property can be obtained.
In addition, the deposited layer of the inorganic oxide improves the adhesion or prevents damage such as cracks and effectively exhibits excellent gas barrier properties. Reactive acrylic resin, polyurethane resin, acrylic resin containing silane coupling agent, water-soluble polymer containing metal alkoxide, ethylene / vinyl acetate A gas barrier layer can be formed as a composite layer by providing a resin layer such as a polymer saponified product.

Of the gas barrier layers, an aluminum foil or a film provided with an aluminum vapor deposition layer is opaque and can also serve as a light shielding layer.
As the strength improving layer, any one of the base films may be additionally laminated as appropriate, and a biaxially stretched high-density polyethylene film or the like may also be laminated as a moisture-proof layer.
A known dry lamination method or extrusion lamination method (sandwich lamination method) can be used for laminating the base film layer, the gas barrier layer, the light shielding layer, and the strength improving layer.

For the sealant layer, low density polyethylene (LDPE), linear low density polyethylene (L / LDPE), ethylene / α-olefin copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene In addition to acrylic acid ester copolymers and ionomers, polypropylene (PP) or copolymers thereof, polyester resins, and the like can be used.
For the lamination of the sealant layer, the above resin can be formed into a film and laminated by a dry lamination method or an extrusion lamination method, or the above resin can be extruded and laminated. However, in the case where the content easily penetrates into the sealant layer, it is preferable to laminate by the dry lamination method.

The linear low density polyethylene (L / LDPE) is excellent in heat seal stability and content resistance, such as stress cracking resistance against surfactants, and polypropylene (PP) is heat resistant, low odor. It is excellent in properties and is suitable for packaging contents that require these performances.
In particular, ethylene / α-olefin copolymer polymerized using a single site catalyst has a narrow molecular weight distribution and a stable copolymerization ratio, so low-temperature heat sealability and hot sealability It is suitable for a sealant layer of a pouch having a step due to a difference in film overlap in a heat seal portion such as a standing pouch in that it can prevent occurrence of pinholes due to omission of a seal.

Next, the structure of the self-supporting bag of the present invention manufactured using the above laminated film and the manufacturing method thereof will be described with reference to the drawings. However, the present invention is not limited to these drawings unless it exceeds the gist.
1 and 2 are front views showing the configuration of an embodiment of the self-supporting bag of the present invention.
FIG. 3 is a conceptual diagram of a main part for explaining an example of the method for producing a self-supporting bag of the present invention.
FIG. 4 is a plan view of the main part for explaining the procedure for trimming the periphery, particularly the bottom part, of the self-supporting bag of the present invention.

FIG. 1 is a front view showing the configuration of the first embodiment of the self-supporting bag of the present invention.
The self-supporting bag 100 shown in FIG. 1 has a gusset portion 4 formed by folding the bottom film inward and inserting the bottom film into the bottom film folding portion 2 between the bottom portions of the front and rear wall films 1, 1 ′. In this case, semicircular bottom film cutouts 3a and 3b are provided in the vicinity of the lower ends of both sides of the bottom film formed in the form and folded inward, and the gusset part 4 has a bay extending from both sides to the center. It is formed by heat-sealing with a bottom-shaped bottom seal part 5 that is concave in a curved shape, and the body part is heat-sealed with the side seal parts 6a, 6b at the left and right edges of the front and rear wall films 1, 1 '. The lower end portion of the gusset portion 4 at the bottom portion is cut by a horizontal straight portion 13 at the center portion, and the diagonal cut portion whose both sides are cut obliquely upward from the inside toward the outside. 14a, 14b, and the horizontal straight portion 13 at the center of the lower end of the gusset portion 4 is cut with a thin blade or roll cutter with the blade edge raised in the direction opposite to the flow direction of the bag film. It is what I did.
Further, the upper part of the self-supporting bag 100 is heat-sealed by the upper seal part 7 having a predetermined width. Since this part is used as a filling port for the contents, an unsealed opening is provided before filling the contents. After being filled, the product is heat sealed and sealed. The lower seal portion 7 is provided with a half-cut line 11 and a notch 12 at its end as a bag opening means.

As described above, the length w of the horizontal straight portion 13 may be 30% or more of the full width of the self-standing bag 100, and is in the range of 30 to 80%. It is preferable.
The maximum height h at the outer end of each of the oblique cut portions 14a and 14b on both sides of the horizontal straight portion 13 is the dimension of the self-supporting bag 100, particularly the width and height of the gusset portion 4 (the folding length of the bottom film). However, in the case of a self-supporting bag having a general size of about 300 to 1200 ml, the maximum height h is preferably in the range of about 2 to 6 mm. However, this maximum height h is the maximum height of the portion excluding the rounded portions when the corners of the oblique cut portions 14a and 14b are rounded.
By adopting the configuration and the manufacturing method as described above, a self-supporting bag that is more excellent in self-supporting stability, has good bottom opening when filling the contents, and has excellent suitability for filling and sealing the contents is provided. be able to.

FIG. 2 is a front view showing the configuration of the second embodiment of the self-supporting bag of the present invention.
The self-supporting bag 200 shown in FIG. 2 is the same as the self-supporting bag 100 shown in FIG. 1 except that a narrow and tapered spout portion 10 is heat-sealed around the outside at one corner of the top of the bag. And provided with a notch 9b on the upper side of the spout 10 and a notch 9a on the lower side to project the spout 10; As the opening means at the opening position of the spout 10, the half cut line 11 and the notch 12 are provided at the upper end thereof, except for the portion provided with the spout 10 in the upper part of the bag. Since it is used for the filling port of the contents, as in the self-supporting bag 100 shown in FIG. 1, it is heat-sealed by the upper seal portion 7 after filling the contents, but as a means for opening the bag below the upper seal portion 7 Half cut line 11 provided and notch 1 at its end 2 is a configuration that is removed because it becomes unnecessary, and the body and bottom other than the top of the bag are formed and configured in the same manner as the self-supporting bag 100 shown in FIG.
By adopting such a configuration and manufacturing method, the contents filled and sealed in the self-supporting bag 200 are fluid contents such as liquid, and when the contents are used, other than a small caliber such as a bottle. Even when the container is transferred to a container, the contents can be safely and easily transferred and used, and the bag is more self-supporting and has a bottom opening when filling the contents. It is possible to provide a self-supporting bag that is excellent in filling and sealing machine suitability for contents.

FIG. 3 is a conceptual diagram of a main part for explaining an example of the method for producing a self-supporting bag of the present invention.
FIG. 3 shows, for example, the order of processing steps from heat sealing to trimming around a bag when a self-supporting bag is manufactured by a bag making machine for a standing pouch. The bag film 20 in a state in which the bottom film with the bottom film cutout portion provided between the lower portions and the bottom film cut-out portion is inserted is sent to the heat seal device 21, and the bottom portion (gusset portion) and both sides of the bag Heat sealing is performed on the side and, if necessary, the upper spout. Although the heat seal device 21 is shown as one block in the figure, it is divided into a plurality of sections as appropriate, such as the bottom and both sides, the spout, and the spot seal at the connection between the bottom and both sides. Heat sealed. Although not shown in the figure, a cooling and crimping device is usually arranged after the heat sealing device 21 to perform cooling and crimping of the heat sealing portion.

After heat sealing each part, the bag film 20 is sent to the cutting process and trimming around the bag is performed. In the self-supporting bag of the present invention, at least the lower end of the bottom gusset portion of the bag is used. First, the first straightening device 22 is used to cut the horizontal straight line portion at the center portion and other portions at separate sections, and the horizontal straight line at the center portion at the lower end portion of the bottom gusset portion of the bag is firstly cut. The portion is continuously cut with a thin blade having a blade edge opposite to the flow direction of the bag film 20 as shown (the end of the cut bag film 20 is a blower or the like). Then, it is sent to the second cutting device 23, and parts other than the horizontal straight portion are punched out by a punching-type punching device such as a die set, and the entire circumference of the bag is trimmed. Is obtained by such graying, after trimming around the bag, although not shown, is integrated is conveyed to the stacking unit is separated into individual bags.
As the first cutting device 22 for cutting the horizontal straight portion at the center of the lower end portion of the bottom gusset portion of the bag, the thickness of the cutting edge is raised in the figure opposite to the flow direction of the bag film 20 in the figure. Although a thin blade (a blade with a straight edge) is shown, it can be replaced with a roll cutter.

FIG. 4 is a plan view of the main part (lower half of the bag) for explaining the procedure when trimming the periphery of the self-supporting bag of the present invention, particularly the bottom, and in the manufacturing method of the self-supporting bag shown in FIG. The bag film 20 that has been heat-sealed at each part in a form in which the bags are connected in the lateral direction is fed in the direction indicated by the arrow, and first enters the first cutting device 22 to enter “[1 ] The portion indicated by the “horizontal straight section cut by the first cutting device (22)” is continuously cut and then sent to the second cutting device 23, where “[2] second cutting” A portion indicated by “a punching line other than the horizontal straight portion punched by the device (23)”, that is, a portion cut obliquely upward from the inside to the outside on both sides of the horizontal straight portion, and then the bag On the left and right sides of the Tsu Sorted in part in which showed a shape punched.
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

The self-supporting bag having the configuration shown in FIG. 2 is manufactured by the manufacturing method shown in FIGS. 3 and 4 with the following dimensions using the wall film and the bottom film having the following configuration, and the self-supporting bag of Example 1 is used. It was.
(1) Configuration of wall surface film 1, 1 ′ (outside) ON film (thickness 15 μm), printing layer / adhesive / aluminum deposition layer (thickness 400 μm), PET film (thickness 12 μm) / adhesive / L / LDPE film ( Thickness 120μm)
(2) Structure of bottom film (outside) ON film (thickness 15 μm) ・ Printing layer / adhesive / aluminum vapor deposition layer (thickness 400 mm) / PET film (thickness 12 μm) / adhesive / L / LDPE film (thickness 100 μm)
The above films are bonded together by the dry lamination method, and the adhesive between the films is a two-component curable polyurethane adhesive for dry lamination (coating amount 3g / m ² when dried). It is a thing.

(3) Dimensions of each part of the self-supporting bag The external dimensions of the self-supporting bag are 110 mm in width and 190 mm in length, and the length of the bottom gusset part 4, that is, the length from the bottom of the bag to the bottom film folding part 2 Was 35 mm.
The length w of the horizontal straight portion 13 at the center of the lower end of the bottom gusset portion 4 is 70 mm, and both sides thereof are cut diagonally upward from the inside toward the outside, and the outside The oblique cut portions 14a and 14b are provided so that the maximum height h at the end portion is 3 mm.

Further, as shown in the figure, the spout portion 10 provided at one corner portion (left corner portion in the figure) of the upper part of the self-supporting bag has an outer periphery of the heat seal portion at the tip side on the upper side and left side of the bag. It was provided at a position on the inner side of each side, the taper angle of the spout portion was set to 64 °, and the opening position, that is, the full width of the position where the half cut line 11 was provided was set to 19 mm. Further, the half-cut line 11 itself was provided at a position where the wall film on the front and back of the bag overlapped by laser light irradiation, and a V-shaped notch 12 was provided at the upper end thereof.
When trimming around the self-supporting bag, the horizontal straight portion 13 at the center of the lower end of the bottom gusset portion 4 is formed on the bag film 20 as shown in the first cutting device 22 of FIG. The blade is cut with a thin blade (the blade is a straight blade) with the blade edge raised in the direction opposite to the flow direction, and the other portions are collectively punched with a push-cut punching device.

  In the structure of the self-supporting bag of Example 1, the length w of the horizontal straight portion 13 at the center of the lower end portion of the bottom gusset portion 4 is changed to 60 mm, and the length of each side is 25 mm. Except for being cut obliquely upward from the inner side to the outer side and changing the maximum height h at the outer end portion to 5 mm, respectively, and providing the oblique cut portions 14a, 14b, all the same as in Example 1. The self-supporting bag of Example 2 was manufactured.

[Comparative Example 1]
In the manufacture of the self-supporting bag according to the first embodiment, when trimming the periphery of the self-supporting bag, the entire circumference including the horizontal straight portion 13 at the center of the lower end portion of the bottom gusset portion 4 is punched out. A self-standing bag of Comparative Example 1 was manufactured by processing in the same manner as in Example 1 except that the punching method was changed to the punching method.

  About the self-supporting bags of Examples 1 and 2 and Comparative Example 1 manufactured as described above, in particular, whether the self-supporting bag has good bottom opening when filling the contents with a filling and sealing machine, and the self-supporting after the contents filling seal. In order to evaluate the quality of the bag's self-supporting stability, each of the 100 self-supporting bags is filled with water from the unsealed upper opening (the upper seal portion 7) as a content using a filling sealer for standing pouches. Fill and seal 350ml, check for bottom opening failure, and for self-supporting stability, place the self-supporting bags after filling and sealing on a flat table and place them on the base of the legs formed on the outer periphery of the bottom of the self-supporting bag. The grounding situation, in particular, the grounding situation at the lower end of the central part before and after the free-standing bag, which is likely to lift, was examined visually.

As a result of the above test, as for the bottom opening property of the self-supporting bag in the filling and sealing machine, both of the self-supporting bags of Examples 1 and 2 had good bottom opening property and good suitability for the filling and sealing machine.
On the other hand, the self-supporting bag of Comparative Example 1 has a phenomenon in which the front and rear films are temporarily attached to the cut surface at the bottom lower end, the bottom opening property is poor, and the liquid level rises at the time of filling. Some of the liquid overflowed when the part 7 was sealed, and the suitability of the filling and sealing machine was poor.
In addition, regarding the self-supporting stability of the self-supporting bags after filling and sealing the contents, the lower ends of the center portions of the self-supporting bags in Examples 1 and 2 and Comparative Example 1 that are particularly prone to lift are on the base surface. It was stably grounded and was more excellent in self-supporting stability.
By the way, assuming a turntable of a microwave oven, I tried standing up a self-supporting bag on a similar turntable and rotating it, but there were no self-supporting bags to tip over.

  The self-supporting bag of the present invention is a standing pouch-type self-supporting bag having a bottom portion formed in a gusset format, and is more excellent in self-supporting stability, and there is no adhesion between the front and back films on the cut surface in the center portion of the bottom gusset portion, When filling the contents with a filling and sealing machine, it has good bottom opening and excellent suitability for the filling and sealing machine, and can be suitably used as a self-supporting bag that seals and wraps liquid contents. There are no particular restrictions on the application.

It is a front view which shows the structure of the 1st Example of the self-supporting bag of this invention. It is a front view which shows the structure of the 2nd Example of the self-supporting bag of this invention. It is a conceptual diagram of the principal part explaining an example of the manufacturing method of the self-supporting bag of this invention. It is a top view of the principal part explaining the procedure at the time of trimming the circumference | surroundings of the self-supporting bag of this invention, especially a bottom part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 'Wall surface film 2 Bottom film return part 3a, 3b Bottom film notch part 4 Gusset part 5 Bottom seal part 6a, 6b Side seal part 7 Upper seal part 8 Outlet part seal part 9a, 9b Notch part 10 Spout part 11 Half cut line 12 Notch 13 Horizontal straight line part 14a, 14b Diagonal cut part w Horizontal straight line length h Maximum height of diagonal cut part 20 Bag film 21 Heat seal device 22 First cutting device 23 Second cutting device 100, 200 Free-standing bag

Claims (2)

  At least the bottom portion of the bag is formed in a form having a gusset portion formed by inserting the bottom film into the inside between the lower portions of the front and back wall film, and the gusset portion has a lower central portion on the inner side and both sides of the bag are It is formed by heat-sealing with a ship-bottom-shaped seal pattern that gradually increases toward the side, and the trunk is formed by heat-sealing the left and right edge portions of the front and back wall films at the side seals. And a center portion of the lower end portion of the bottom gusset portion is cut by a horizontal straight line, and both sides thereof are cut obliquely upward from the inside toward the outside, each part of the self-standing bag After heat sealing, when trimming the periphery of the bag, at least the horizontal straight part at the center of the lower end of the bottom gusset part is thin with a blade edge raised in the direction opposite to the film flow direction. Self-standing bag, characterized in that it is produced by the method of cutting with a knife or roll cutter.   The self-supporting bag according to claim 1, wherein a spout portion having a narrow width is provided by a heat seal pattern at an upper corner portion of the self-supporting bag.

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