JP2004114700A - Packaging bag and its manufacture method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable it to manufacture a packaging bag at a high speed without inferior goods. <P>SOLUTION: The packaging bag, which is provided with facing plane sections, a couple of facing side sections interposed between the plane sections and a bottom section closing the bag bottom portion, is formed by the steps such that a rectangular-shaped sheet material is tucked down as the bottom section and the packaging bag is vertically put by more than one using a boat-shaped member with delta wing on both sides. At this time, the plane section and the side section are composed of a belt shape film. The side sections formed by the belt shape film are sandwiched by the delta wings at an each designated interval in the longitudinal direction. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a method for manufacturing a packaging bag having a flat bottom surface and a packaging bag.

The present applicant discloses in Patent Document 1 a method of manufacturing a packaging bag having a flat bottom (flat bottom) made of a thin packaging material.

That is, the method of forming the packaging bag 1 as shown in FIG. 20 is disclosed. When the contents of the packaging bag 1 are completely contained, the folded bottom portion 2 becomes flat and becomes a so-called upright shape. The packaging bag 1 includes flat opposing flat portions 3, 3 and side portions 4, 4 connecting both end portions of the flat portions 3, 3, and being folded inside by a fold line 4a. It comprises a bottom surface portion 2 for closing the bottom surface of the cylindrical body composed of the flat surface portion 3 and the side surface portion 4. For the bottom surface portion 2, a bottom surface forming sheet 10 as shown in FIG. 23 is prepared, and this is folded back at the longitudinal center line to form a bottom fold line 11 (FIGS. 21 and 24). The fold lines 11a, 11a are formed by bending an arbitrary point P, P in the vicinity of both ends, from the base points P, P to both ends of the sheet 10 in a direction opposite to the original fold direction of the bottom fold line 11. To form At the same time, the line connecting the two corners at both ends of the sheet 10 to the base points P, P is folded as four ridgelines 12, 12,... 12 protruding inwardly of the bag to correspond to the folds on the side surface of the bag. Opening surfaces 13 and 13 are formed. The bottom-forming sheet 10 folded in this way is inserted into the bottom of the cylindrical body composed of the flat part 3 and the side part 4, and the outer bottom edge 20 outside the folded sheet 10 as shown in FIG. , 21 form a seal portion S welded to the inner surface of the flat portion 3 and the inner surface of the side portion 4 respectively.

(4) The front portion 3 and the side portion 4 are appropriately sealed to form a seal portion S (FIG. 23).

Japanese Patent Application No. 6-114803

Since a specific apparatus and method for manufacturing a packaging bag having such a flat bottom surface (flat bottom) are not disclosed in the above-mentioned application, the present invention can manufacture such a packaging bag at high speed and without defective products. It is an object to provide a method for manufacturing such a packaging bag and a packaging bag.

Therefore, in the present invention, a pair of opposing flat portions and a folding line interposed between the flat portions are formed in the center in the width direction, and the folding lines are folded inside the packaging bag. In producing a packaging bag having a pair of side portions and a bottom portion that closes the bottom portion of the packaging bag, as the bottom portion, a rectangular sheet material, a center fold line positioned at the center in the width direction of the sheet material is used. Arbitrary points located near both sides of the sheet material on the center fold line are respectively set as base points, and from these base points to both ends of the sheet material are convex in a direction opposite to a bending direction of the center fold line. A folded reverse folding line is formed, and a line connecting the base point and two corners at both ends of the sheet material is bent so as to be convex in the same direction as the folding direction of the center folding line. A method of manufacturing a packaging bag using a boat-shaped member having triangular wings formed on both sides of the sheet material, wherein the packaging bag is formed by connecting a plurality of the packaging bags in a direction corresponding to a vertical direction thereof. The flat part and the side part of the bag are formed of a band-shaped film, and at predetermined intervals in the longitudinal direction, the reverse folding line of the boat-shaped member is formed by the folding line of the side part formed by the band-shaped film. And a method of manufacturing a packaging bag including a step of disposing the side portions formed by the strip-shaped film between the triangular wings.

In the present invention, in the method for manufacturing a packaging bag, the boat-shaped member and the side portion may be locally formed in a state in which the side portion formed by the band-shaped film is disposed between the triangular wings of the boat-shaped member. And a point sealing step for bonding to the substrate.

Further, in the present invention, in the method for manufacturing a packaging bag, in the bottom sealing step of bonding the boat-shaped member and the flat portion and the side portion formed by the band-shaped film, and after the bottom sealing step, the boat-shaped member is provided. And a cutting step of cutting the film with two cut lines separated by a predetermined width in the longitudinal direction of the strip-shaped film, with the skirt portion interposed therebetween.

In the present invention, in order to solve the above-mentioned problem, a pair of flat portions facing each other and a fold line is formed at the center in the width direction, interposed between the flat portions, and the fold line is formed inside the packaging bag. In a packaging bag provided with a pair of opposed side portions folded into the bottom portion and a bottom portion closing the bottom portion of the packaging bag, a point seal portion in which the side portions and the bottom portion are locally bonded is formed. Adopted packaging bags.

Further, in the present invention, in the packaging bag, the bottom surface portion may be provided with a rectangular sheet material provided with a center fold line located at the center in the width direction, and positioned on the center fold line near both sides of the sheet material. Each of the base points is defined as a base point, and a reverse fold line is formed such that the base point and both ends of the sheet material are bent in a direction opposite to a bending direction of the center fold line. A boat-shaped member in which lines connecting the two corners at both ends of the sheet material are bent so as to be convex in the same direction as the bending direction of the center folding line, and triangular wings are formed on both sides of the sheet material. The point seal portion is provided by bonding the triangular wing of the boat-shaped member to the side member.

According to the present invention, a packaging bag having a flat bottom can be manufactured at a high speed. In addition, since a point seal for locally bonding the side surface portion and the bottom surface portion is provided, it is possible to prevent the bottom surface portion from being arranged at an unexpected position in the manufacturing process, and to manufacture a high-quality packaging bag.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

In FIG. 1, the side films 30, 30 forming the side portions 4 of the flat bottom packaging bag described above are flowed in parallel in an upright state, and the side films 30 are folded right and left outward about a vertical central axis in a vertical direction. The upper and lower pieces 30a and 30b are formed in an overlapping manner (FIG. 2). In this way, the bottom-forming sheet 10 formed by bending the bottom-forming sheet 10 as shown in FIG. 3 so as to bridge the two parallel-flowing side films 30 is sandwiched between the open surfaces 13 on both sides thereof. As shown in FIG. 4, the bottom forming sheet 10 is engaged with the two side films 30 in a ladder-like manner at a predetermined interval, and above and below the combined film U in which the bottom forming sheet 10 and the side film 30 are combined. The flat films 31, 31 forming the front and back surfaces of the packaging bag are supplied to form the overlapping band-shaped film B. After that, the laminated band-shaped film B is side-sealed and bottom-sealed, and its side is cut along cut lines l1 and l1 and the bottom and top are cut along cut lines l2 and l3, so that one end as shown in FIG. An open flat bottom packaging bag is formed. After the contents of the packaging bag are filled, the opening at the top of the packaging bag is closed.

Next, an outline of the flat bottom packaging bag manufacturing apparatus will be described with reference to FIG.

In FIG. 5, a raw material 51 supplied from a wide raw material roll 50 is drawn out by a feeding roll 52 (drive roll) and separated into four rolls from a separation roll 53. The side films 56 and 57 separated into the upper and lower two films passing through the two transport paths are processed while flowing through the central portions of the first and second transport paths of the flat films 54 and 55.

The side films 56 and 57 are sent to a separation roll 60 while simultaneously adjusting the tension by a tension adjusting device 58, where the side films 56 and 57 are separated in two directions, as shown in FIG. The side film 30 is folded outward in a standing state (FIG. 2). Each of the side films 56, 57 is composed of a pair of left and right side films, which are cut in half by cutting devices 67, 67 and sent to folding devices 61, 62. The left and right flows of the separated side film form third and fourth transport paths. In FIG. 5, the third and fourth transport paths are formed in the side films 56 and 57, respectively. On the other hand, in front of the separation roll 60, a bottom sheet roll 63 is provided, and the film from this roll 63 is cut by a cutter 64 provided in a fifth transport path including a dancer roller 164, as shown in FIG. Such a rectangular bottom sheet 10 is formed. The bottom forming sheet 10 is folded by the folding and joining machine 35 as shown in FIG. 22, and the bottom forming sheet 10 is joined to the two side films 30 to form a joint film U. Thereafter, the two bonded films U are combined with the flat films 54 and 55 by the overlapping roll 65 to form the overlapping band-shaped film B. The overlapping belt-shaped film B is intermittently fed by a servomotor that drives the overlapping roll 65 (drive roll).

Next, details of the apparatus will be described.

The packaging bag manufacturing apparatus according to the present invention makes a so-called multi-imposition, in which two rows of bags are finally formed from one raw roll 50 (FIG. 5), and two bags are simultaneously cut out from the film row. It is possible. The raw roll 50 is formed to be wide as shown in FIG. 6, and four flat films 270 (a is a front side, b is a rear side flat film) are printed on the center of the raw roll film 51. ing. On both sides of the flat film 270, side films 271 (a is a right side film and b is a left side film) are printed.

Therefore, the raw film 51 is printed so that two sets of packaging bags can be simultaneously manufactured in the width direction. The raw material continuously fed by the feed roll 52 from the raw material roll 50 is cut and separated along four cutting lines of the raw material film 51 by a cutter 70 provided along a traveling path of the raw material film 51. After passing through the roll 53, the film is separated into four elongated films. That is, the flat film 270 and the side film 271 are each separated into two sets of streams.

In order to align the two sets of side films 56 and 57 of the bonding film U with the bottom surface forming sheet 10 and align the bonding film U with the two sets of flat films 54 and 55, the side films 56 and It is necessary to adjust the tension with the flat film 57 and the flat films 54 and 55.

In the present embodiment, two sets of flat films 54 and 55 are formed by the driving roll 65 (note that a few driving rolls are provided on the downstream side of the folding and joining machine, and the driving rolls are rotated by a servomotor). The side films 56 and 57 are fed while being adjusted in tension by a tension adjusting mechanism 58.

That is, a photoelectric sensor 175 is provided at an appropriate position on the downstream side of the tension adjusting mechanism 58 between the side films 56 and 57, and the feed timing (speed) of each of the side films 56 and 57 is detected by the photoelectric sensor 175 ( (Fig. 5). When the photoelectric sensor 175 detects that the feed speed of the side films 56 and 57 has increased from the reference speed, the feed speed is controlled by brake devices 73 and 74 as shown in FIGS. That is, each of the brake devices 73 and 74 has a resistance bar 78 facing the guide roller 77. The resistance bar 78 presses the side films 56 and 57 against the peripheral surface of the guide roller 77 by the operation of the air cylinder 79, and The feed speeds (tension) of 56 and 57 are adjusted.

As shown in FIG. 7, the tension adjusting device 58 has guide rollers 80... 80, 81... 81 supported by a frame, and under these guide rollers 80, 81, dancer rollers 83, 83; Is provided. The dancer rollers 83 and 84 are supported by parallel bars (supporting members) 85 and 86. The parallel bar 85 is rotatably mounted on a fixed frame around a fulcrum P1, and the parallel bar 86 is connected to a fixed frame by a fulcrum P2. It is attached rotatably as the center.

The parallel bars 85 and 86 are connected by a connecting link 87, and the parallel bars 85 and 86 rotate in parallel with each other. The tip of the parallel bar 85 is connected to the tip of an operating shaft 91 of an air cylinder 90, and the tension of the side films 56 and 57 is adjusted by the operation of the air cylinder 90. Since the air cylinder 90 rotates left and right about the fulcrum P3, the rotation angle θ of the parallel bars 85 and 86 corresponding to the same expansion and contraction length of the operating shaft 91 of the air cylinder 90 is determined by the parallel bars 85 and 86 and the air. It differs slightly depending on the rotational position of the cylinder 90 with respect to the fulcrum P3. Therefore, a potentiometer 93 as a detecting member is provided at the fulcrum P1 of the parallel bar 85, and the rotational position of the parallel bars 85 and 86 is detected by the potentiometer 93, and a desired tension is obtained corresponding to the position. The extension length of the operating shaft 91 is adjusted.

As shown in FIG. 9, the feed amount of the side film 56 (57) is measured by detecting, with the photoelectric sensor 73, marks 100 printed at regular intervals in the center of the left and right side surfaces of the side film 56. . The superposed strip film B is detected by a sensor 176 having the same structure as that shown in FIG. 9, and the comparison between the signal from the sensor 176 and the signal from the sensor 175 synchronizes the flat film and the side film. The tension of the flat films 54 and 55 is adjusted by tension adjusting devices 170 and 171. These tension adjusting devices include a dancer roller 172, a support bar 173, and a potentiometer 174 for detecting the rotational position of the support bar 173. I have.

The tension adjustment of the flat films 54 and 55 is performed by first adjusting a feed amount of a drive roll for feeding the overlapped band film B by adjusting a servomotor, and feeding the raw material so that a support bar of the tension adjustment device is horizontal. Adjust the rotation of the roll 52. The level of the support bar is adjusted by a potentiometer 174. In this way, the tension of the flat films 54 and 55 is kept constant.

Then, the tension of the side films 56 and 57 is adjusted to be slightly smaller than that of the flat films 54 and 55 by a tension adjusting device 58, and the loosening tension is adjusted by operating the brake devices 73 and 74. You.

After passing the tension adjusting device 58, the side films 56 and 57 are separated into left and right side films by a cutting device 67 (FIG. 5) through a separation roll 60, and the side films 56 are separated into films 56a and 56b. (One side film 56 is described in FIG. 10). The left and right side films 56a and 56b are run upright by a turn bar (not shown), and the upright side films 56a and 56b are turned at right angles by the upright rollers 120a and 120b to run opposite to each other. Triangular plates 121a and 121b are provided adjacent to the guide rollers 120a and 120b, and the bottom sides thereof are close to the guide rollers, and the running direction of the side film is slightly outwardly directed from the tip corresponding to the apex of the triangular plate. The film on both sides is folded outward by passing through a folding roller provided near the vertex. These guide roller, triangular plate and folding roller form a folding device 61 (FIG. 5).

Next, the structure of the foldable coupling machine 35 for forming the coupling film U as shown in FIG. 3 will be described.

As shown in FIGS. 11 and 12, the folding coupling machine 35 has a main body 300, and a front plate 301 is provided on the front surface of the main body 300. The front plate 301 has H-shaped openings 302, 302. The bottom forming sheet 10 formed and sent at a predetermined timing from above so as to close the H-shaped opening 302 is positioned and fixed by the holding members 303 and 303. An extruded body 304 is located opposite the H-shaped opening 302 of the front plate 301. The extruded body 304 has a moving frame 305. , 306 are attached, and a holding plate 307 is fixed to the tip of the guide bar 306. On both sides of the upper end of the holding plate 307, two formed plates 308, 308 are provided in a vertical direction, and the formed plates 308, 308 have a tip-like shape like an arrow. Then, the forming plates 308, 308 are inserted into the vertical portions 302a, 302a of the H-shaped opening of the front plate 301 while pushing the bottom-forming sheet (at this time, the holding members 303, 303 hold the bottom-forming sheet. Open). On the other hand, the moving frame 305 has a vertically extending support frame 309, and the support frame 309 supports the rear end of the horizontal push plate 310 extending horizontally, and the front end thereof is It extends through the upper opening of the holding plate 307 and extends between the left and right forming plates 308 having the shape of an arrow.

Now, when the moving frame 305 moves rightward in the drawing from the state of FIG. 11, the arrow-shaped tips of the forming plate 308 push the vicinity of both sides of the bottom surface forming sheet 10 into the vertical portion 302a of the opening 302 of the front plate. . Slightly later than this, the tip of the horizontal pressing plate 310 is inserted into the horizontal portion 302b provided in the H-shaped opening, and the bottom forming sheet 10 is formed into a shape as shown in FIG. That is, in this state, the bottom surface forming sheet 10 is formed of triangular vertical wing portions 10a and 10a formed on both sides and an intermediate folded horizontal portion 10b.

で The pushing operation of the forming plate 308 is completed in a state where the holding plate 307 is in contact with the front plate 301, but the moving frame 305 further advances from this state. At this time, the guide bar 306 is inserted into the moving frame 305, the moving frame 305 and the holding plate 307 approach each other, and the horizontal pressing plate 310 further presses the bottom forming sheet 10 into the folding / coupling machine 35. A substrate 320 is extended behind the front plate 301, as shown in FIGS. 12, 14 and 15, on which the horizontal pressing plate 310 and the bottom sheet 10 pass. A restricting plate 321 is provided at a small interval so as to obtain the restricting plate 321. The restricting plate 321 has a vertically long guide plate portion 322 for guiding the horizontal pressing plate 310, and the guide plate portion 322 is closer to the front plate 301. 13 are provided on both sides of the support plate 323. On these auxiliary control plates 323, the front end of the horizontal portion 10b of the bottom surface forming sheet 10 in FIG. Thereby, the inclined sides 323a and 323a are provided so that the upper piece of the vertical wing portion 10a of the bottom surface forming sheet rises and is folded inward. At this time, the lower piece of the vertical wing portion 10a is expanded with the expanding sides 320a, 320a formed at the front end of the substrate 320 and the auxiliary substrate 420 provided below the substrate 320 as shown in FIG. It is guided by the sides 420a and 420a and is horizontal.

When the upper piece of the vertical wing portion of the bottom surface forming sheet is bent inward from substantially vertically above and the lower piece of the vertical wing portion is in a horizontal state, the guide piece 330 is guided by the guide roller 330 on the guide plate portion 322. The left and right side films 56a and 56b of the sheet folding enter between the open surfaces of the lower piece of the vertical wing and the upper piece of the vertical wing (FIG. 12). Further, when the horizontal pushing plate 310 moves forward, the side film is sandwiched between the upper piece 10a1 of the vertical wing and the lower piece 10a2 of the vertical wing as shown in FIG.

That is, on the front side of the guide plate portion 322, a vertical wing closing portion 326 having inclined widened sides 325 and 325 acting opposite to the vertical wing rising portion 324 is provided. When the bottom sheet is advanced by the horizontal pressing plate 310, the left and right side films 56a, 56b are sandwiched between the upper and lower vertical wings. The vertical wing closing portion 326 extends in the width direction, and two openings 330, 330 are formed in the vicinity of the inclined widening side 325, and these openings 330 are formed in the sealing portion S of the vertical wing. (FIG. 23). Heating rods 331 and 331 as temporary fixing devices are provided corresponding to the openings 330, and these heating rods 331 are passed through the openings 330 and pressed against the vertical wings of the bottom surface forming sheet 10 so that the vertical wings 10a, 10a and the left and right side films 56a, 56b are bonded at bonding points 340, 340 and temporarily fixed. Thus, the bonding film U as shown in FIG. 3 is formed. The bonding point 340 exists at a position corresponding to the seal portion S to be finally sealed.

底面 Since the bottom surface forming sheet 10 is formed intermittently by the folding and joining machine 35, the joining film U is sent intermittently. This feeding is also controlled by a method as shown in FIG. The bottom forming sheet 10 and the left and right side films 56a and 56b are formed at a predetermined interval at a predetermined timing. In the folding and joining machine 35, one flow of the film has been described. Processed at the same time.

The bonding film U formed as described above is synchronized with the flat films 54 and 55 fed from above and below by the overlapping rolls 65 and 65 provided on the downstream side of the folding and bonding machine 35 as shown in FIG. To form the overlapping band-shaped film B.

Next, as shown in FIG. 19, the side of the laminated band-shaped film B is firstly sealed by a side seal portion 400, and the same portion is sealed twice in order to ensure the sealing. At 401, the side-sealed portion is once cooled.

Next, the bottom of the bag is sealed twice by the bottom seal portion 402 and cooled by the cooling portion 403. Subsequently, the cutter 404 separates the film from the center of the overlapped band-shaped film B to the left and right to form a film flow of two rows of band-shaped bags. Then, the chamfered cuts Q on both sides of the bottom of the bag are formed by the cutter table 406 and cut along the cutting lines by the forming table 407 as shown in FIG. An open and upright bag is formed.

It is explanatory drawing of the flow state of the side film comprised as a side part. It is explanatory drawing of the state which folded the side film outward. It is a state explanatory view of a binding film. It is an explanatory view of a cut state of a layered film. It is a schematic structure figure of the manufacturing device for manufacturing the packaging bag of the present invention. It is a perspective view of a raw roll. It is a schematic structure figure of a tension adjustment device. FIG. 4 is a perspective view of a brake device for adjusting the tension of the side film. It is a perspective view of the detection member which detects the flow of a packaging bag film. It is a perspective view of the folding device which folds two side films. It is a perspective view of a foldable coupling machine. It is a perspective view of the main body of a foldable coupling machine. FIG. 4 is an explanatory diagram of a molding state of a bottom surface forming sheet when a molded body is inserted into a front plate of a folding and joining machine. FIG. 5 is an explanatory diagram of a molding state of a bottom surface forming sheet in a main body of the folding and joining machine. It is a perspective view which shows the structure of the front part of the main body of a folding coupling machine. It is a longitudinal cross-sectional view of the board | substrate of an insertion coupling machine, and a control plate. FIG. 4 is an explanatory view of a state of connection between a bottom surface forming sheet and a side film formed by a folding connection machine. It is a perspective view of a film stacking apparatus. It is a processing process figure of a layered film. It is a perspective view of the formed flat bottom packaging bag. It is a molding intermediate | middle state perspective view of a bottom surface forming sheet. It is a seal position explanatory view of a bottom surface forming sheet. It is a seal position explanatory view of a flat bottom packaging bag. It is explanatory drawing of the folding state of a bottom surface formation sheet.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 ... Flat bottom packaging bag 10 ... Bottom forming sheet 31 ... Folding coupling machine 50 ... Raw material roll 54, 55 ... Flat film 56, 57 ... Side film 58 ... Tension adjusting device 61, 62 ... Folding device 73 ... Photoelectric sensor 83 , 84 ... Dancer rollers 85, 86 ... Parallel bar 300 ... Body 301 ... Front plate 302 ... H-shaped opening 304 ... Press-formed body B ... Overlapping strip film U ... Bonding film

Claims (5)

A pair of opposed flat portions, a fold line is formed between the flat portions, and a folding line is formed at the center in the width direction, and the fold line is folded inward of the packaging bag. In manufacturing a packaging bag having a bottom portion that closes the bottom portion of the packaging bag, a rectangular sheet material is provided as the bottom portion with a center fold line located at the center in the width direction. , An arbitrary point located in the vicinity of both sides of the sheet material as a base point, and a reverse fold line bent from these base points to both ends of the sheet material in a direction opposite to the bending direction of the center fold line. Is formed, and lines connecting the base point and the two corners at both ends of the sheet material are respectively bent so as to be convex in the same direction as the bending direction of the center fold line, and on both sides of the sheet material. three The boat member formed of the wing, a manufacturing method of the packaging bag to be used,
The flat portion and the side portion of the packaging bag are formed of a band-shaped film so that the packaging bag is formed in a plurality in a direction corresponding to the vertical direction, and at predetermined intervals in the longitudinal direction, Aligning the reverse fold line of the boat-shaped member with the fold line of the side portion formed by the band-shaped film, and disposing the side portion formed by the band-shaped film between the triangular wings. A method of manufacturing a packaging bag. A point sealing step of locally bonding the boat-shaped member and the side portion in a state where the side surface portion formed by the strip-shaped film is disposed between the triangular wings of the boat-shaped member, The method for producing a packaging bag according to claim 1. A bottom sealing step of bonding the boat-shaped member and the flat portion and the side portion formed by the band-shaped film,
After this bottom sealing step, a cutting step of sandwiching the skirt portion of the boat-shaped member therebetween, cutting at two cut lines separated by a predetermined width in the longitudinal direction of the band-shaped film,
The method for producing a packaging bag according to claim 1, further comprising: A pair of opposed flat portions, a fold line is formed between the flat portions, and a folding line is formed at the center in the width direction, and the fold line is folded inward of the packaging bag. In a packaging bag having a bottom portion closing a bottom portion of the packaging bag,
A packaging bag having a point seal portion formed by locally bonding the side portion and the bottom portion. The bottom surface portion is provided with a rectangular sheet material, a center fold line located at the center in the width direction thereof, and on this center fold line, arbitrary points located near both sides of the sheet material are used as base points, respectively. A reverse fold line is formed that is bent from the base point to both ends of the sheet material in a direction opposite to the bending direction of the center fold line, and further includes the base point and two corners at both ends of the sheet material. Is a boat-shaped member which is bent so as to be convex in the same direction as the bending direction of the center fold line to form a triangular wing on both sides of the sheet material,
The packaging bag according to claim 4, wherein the point seal portion is provided by bonding the triangular wing of the boat-shaped member and the side member.

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