JP2913170B1 - Breathable packaging bag and manufacturing method thereof - Google Patents

Abstract

The present invention provides a breathable packaging bag and a method of manufacturing the same, which can be sold over the counter in a state in which products requiring particularly breathability, such as fresh fruits and vegetables, are stored. In a configuration in which side seal portions are formed at both side edges of a bag in which front and back net sheets made of a synthetic resin are disposed with an article storage room interposed therebetween, and the two net sheets are welded to each other. In the portion where the portion faces the article storage room, while forming a stretchable mesh in which a number of monofilament-shaped filaments are crossed and integrated, the side seal portions are provided along both side edges of the bag body. The seal tape piece made of the synthetic resin film and the front and back net sheet portions are integrally welded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breathable packaging bag which can be sold over the counter in a state in which products which require particularly breathability, such as fresh fruits and vegetables, are stored, and a method for producing the same.

[0002]

2. Description of the Related Art Small vegetables such as green soybeans and okra, and small fruits such as kumquat (collectively referred to as fresh fruits and vegetables including such vegetables and fruits) are stored in packaging bags and sold over the counter. Therefore, it is necessary to guarantee air permeability in order to maintain freshness. For this reason, conventionally, there has been provided a tubular bag formed of a net tube having a stretchable mesh in which a large number of monofilament-shaped filaments are crossed and integrated.
That is, while cutting the net tube to a predetermined length, forming a tubular bag having a bottom by bundling and welding one end, storing fruit and vegetables in the tubular bag, and then stapling the paper header. This closes the opening of the tubular bag. However, since such a tubular bag is formed in a tubular shape, it swells in a radial direction in a state in which fruits and vegetables are stored, and the appearance for displaying products is not good.

[0003] By the way, the present applicant has proposed various types of packaging bags which can be sold over the counter in a state in which various small items are stored. Such packaging bags include a front film made of a synthetic resin film and a packaging film. A substantially rectangular bag is constructed by fusing and welding the back film,
If necessary, a hanging header is provided at the top of the bag.
Accordingly, while the bag is swelled in both front and back directions in a state in which the product is stored, the periphery is distorted, but the periphery can be generally maintained in a shape close to the original rectangle, so that the appearance for displaying the product is not bad. However, when such a packaging bag is used as a packaging bag for fresh fruits and vegetables as described above, the stored fresh fruits and vegetables are hermetically sealed, poor in air permeability, and quickly deteriorated in freshness. That is, fresh fruits and vegetables maintain their freshness by respiration, and if the air permeability is impaired, they deteriorate early.

[0004]

Therefore, when forming a packaging bag for fresh fruits and vegetables, the present inventors formed a net sheet made of synthetic resin on both sides of the bag body and welded the front and back net sheet portions. By forming a substantially rectangular bag as a whole, the necessary and sufficient air permeability is guaranteed, and the appearance and appearance of the product in the stored state as described above are good, and the ideal packaging for fresh fruits and vegetables. I knew that I could provide a bag.

[0005] Then, when a material usable for the synthetic resin net sheet constituting such a packaging bag was searched, the following problems were further found. (1) Fresh fruits and vegetables as described above are relatively small bulk goods, but due to the packaging of fixed quantities, the packaging bag easily swells when the goods are stored from a flat state, ideally a net. It is desirable that the part expands and contracts. Therefore, if you use a synthetic resin net sheet that constitutes a stretchable mesh made by intersecting and integrating a large number of monofilament-shaped filaments, if both front and back net sheet parts are superimposed and fused and welded on both side edges It has been found that a bag that meets this requirement can be provided. However, when products are actually stored in a packaging bag made with such a net sheet, the fusing and welding parts of the front and back net sheets are easily peeled off, and it turns out that it is completely unusable. did. (2) Regarding the bag making method, as in the case of the conventional film bag, after the band-shaped net sheet is polymerized half-fold in the band width direction, the sheet is formed at predetermined intervals in the longitudinal direction of the half-folded net sheet. A technique for fusing and welding the front and back net sheet portions in the width direction is expected. According to this, bag production with high productivity can be performed. However, since the net sheet constituting the mesh formed of the monofilament-shaped filaments as described above is rich in elasticity and extremely low in shape retention, it is extremely difficult to fold the strip-shaped net sheet in half. In particular, since the mesh is easily deformed while expanding and contracting at the time of half-folding, the opposing edges of the folded net sheet are not aligned in line with each other, and it is extremely difficult to form a bag of a desired form. is there.

[0006]

SUMMARY OF THE INVENTION The present invention provides a breathable packaging bag which solves the above problems and a method for producing the same.

[0007] In view of this, the breathable packaging bag of the present invention is configured as means by positioning both net sheet portions at both side edges of a bag in which front and back net sheet portions made of synthetic resin are arranged with the article storage room interposed therebetween. the a breathable packaging bag obtained by forming the side seal portions are welded to each other, front and rear net seat, together constitute a multiple monofilament telescopic mesh which striatum crossed the by allowed integrated The Sai
Form a flat ribbon at the seal
The side seal portion is formed by integrally welding a seal tape piece made of a synthetic resin film provided along both side edges of the bag body and the ribbon portion of the front and back net sheet portions.

[0008]

Preferably, the side seal portion is welded and integrated with the front and back net sheet portions sandwiched between a pair of seal tape pieces. May be integrated by welding.

In a preferred embodiment of the present invention, the front and back net sheet portions are formed by cutting a net tube, and are folded back along the bottom of the bag.

The method for producing a breathable packaging bag according to the present invention comprises a synthetic resin net having a stretchable mesh formed by intersecting and integrating a large number of monofilament filaments. A net tube paying out process in which the tube is fed out in the longitudinal direction as a flat flat form having substantially parallel folding curves, and a front and back net sheet portion in a half-folded state by cutting the flat net tube along one bending curve. A cutting step of forming a half-folded net sheet provided with: A side sealing step of forming a side sealing portion by welding and integrating the sheet portion, and Lies in comprising a dividing step for dividing the Idoshiru portion.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

[Embodiment of Breathable Packaging Bag] As shown in FIG. 1, the bag body 1 has an article storage chamber 4 between a front net sheet portion 2 and a back net sheet portion 3 arranged on both sides. The two net sheet portions 2, 3 are located on both side edges of the bag body 1.
Are provided with side seal portions 6, 6 for welding to each other.

In the illustrated example, the front and back net sheet portions 2 and 3
Is a form in which one net sheet is folded along the bottom 7 of the bag body 1, and the front and back net sheet portions 2 and 3 are formed by two separate front and back net sheets, respectively. By providing welding portions similar to the side seal portions 6 on both side edges of the body 1 on the bottom portion 7 of the bag body 1, three sides except for the upper portions of the front and back net sheet portions 2 and 3 may be welded.

The front and back net sheet portions 2 in a folded state,
3 have opening edges 2a, 3a aligned in a straight line with each other, whereby the article storage chamber 4
Opening 8 is formed.

An opening edge 3a of the back net sheet portion 3 is provided with a sealing piece 9 made of a synthetic resin film extending upward, and the sealing piece 9 is opened in a state of being superposed on the outside of the back net sheet portion 3. Sealing piece welding lines 10a and 10b to be welded in the width direction of the edge 3a and the lower part are formed. still,
An adhesive layer 12 made of a pressure-sensitive adhesive covered with a release film 11 is provided near the free end of the sealing piece 9.

A receiving piece 13 made of a synthetic resin film is provided at the opening edge 2a of the front net sheet portion 2. The receiving piece 13 is superposed on the outside of the opening edge 2a and the opening edge 2a and the lower portion are formed. Welding wire 14a for welding in the width direction of
14b is formed.

Therefore, after the release film 11 is peeled off,
The opening 8 can be closed via the sealing piece 9 by bending the sealing piece 9 and bonding the adhesive layer 12 to the outer surface of the receiving piece 13. At this time, instead of providing the adhesive layer 12 with the release film 11 on the sealing piece 9,
3 may be provided. In addition, a known chuck tape may be provided instead of the opening / closing fixing means using the adhesive layer 12.

As shown in FIG. 2, the front and back net sheet portions 2 and 3 are provided with a stretchable mesh formed by intersecting and integrating a large number of monofilament filaments 15 having a substantially circular or elliptical cross section. Make up the seat.

Therefore, the front and back net sheet portions 2 and 3 constitute a thread portion 16 having a substantially circular or elliptical cross section by the filament 15 at a portion facing the article storage chamber 4.
At the portions located on the welding wires 10a, 10b and 14a, 14b and the side seal portions 6, 6, a ribbon portion 17 having a flat filament 15 is formed. Such a ribbon portion 17 is formed by continuously pressing the filaments 15 constituting the front and back net sheet portions 2 and 3 until a flat sheet-like ribbon is formed by a heating element.

That is, a heating member such as a heat roller is pressed from the outer surface of the sealing piece 9 in a state where the sealing piece 9 is overlaid on the back net sheet portion 3, so that a linear sealing in the width direction of the bag body 1 is performed. The piece welding lines 10a and 10b are formed, and at this time, the ribbon formed on the back net sheet 3 is welded to the sealing piece 9.

Similarly, a heating element such as a heat roller is pressed from the outer surface of the receiving piece 13 in a state where the receiving piece 13 is superimposed on the front net sheet portion 2, thereby forming a straight line in the width direction of the bag body 1. The receiving piece welding lines 14 a and 14 b are formed, and at this time, the ribbon part formed on the front net sheet part 2 is welded to the receiving piece 13.

As shown in FIGS. 1C and 2, the bag 1
Side seal portions 6, 6 formed on both side edges of the bag body 1 are provided with a seal tape piece 18 made of a synthetic resin film along both side edges of the bag body 1, and the seal tape piece 18 and the front and back net sheet portions 2, 3 is formed by welding and integrating. That is, by pressing a heating element such as a hot plate across both sides of the side seal portion 6, the ribbon portion 17 is formed while deforming the filament 15 of the front and back net sheet portions 2, 3 while forming the ribbon portion 17. Is welded and integrated with the seal tape piece 18.

As described above, the grid-like ribbon portion 1 in which the linear portions 15 of the front and / or back net sheet portions 2 and 3 are flattened.
7, the welding lines 10a, 10b
, 14a and 14b, the ribbon 17 is
And it becomes possible to firmly couple to the receiving piece 13 by surface welding instead of linear welding.

The welding pieces 14a, 14b of the receiving piece 13
Can be formed by crimping a heating body such as a hot plate from the outside of the receiving piece 13 with the receiving plate inserted inside the front net sheet portion 2. Similarly, the sealing piece welding lines 10 a and 10 b of the sealing piece 9 are also formed on the back net sheet portion 2.
It can be formed by crimping a heating body such as a hot plate from the outside of the sealing piece 9 in a state where the receiving plate is inserted inside the inside.

In the embodiment shown in FIGS. 1 and 2, the side seal portions 6, 6 have a pair of seal tape pieces 18a,
18a is provided sandwiching the front and back net sheet portions 2, 3;
A sandwich structure in which a ribbon portion 17 formed by the front and back net sheet portions 2 and 3 is welded and integrated between a pair of seal tape pieces 18a and 18a by pressing a pair of opposed heating members such as a hot plate and the like. doing. In this case, not only is the ribbon portion 17 welded to each of the seal tape pieces 18a, 18a, but also a pair of seal tape pieces 18a, 18a are welded to each other through the mesh of the ribbon portion 17.

In the embodiment shown in FIG. 8, which will be described later, the side seal portions 6, 6 have a structure in which one sealing tape piece 18 is interposed between the front and back net sheets 2, 3.
Each of the ribbon portions 1 formed by the front and back net sheet portions 2 and 3 is formed by pressing a heating body such as a pair of opposed heat plates against the front and back net sheet portions 2 and 3.
7 and 17 are welded and integrated on both surfaces of the seal tape piece 18 to constitute a sandwich structure.

[First Embodiment of Bag Making Method] The material for forming the front and back net sheets 2 and 3 of the bag 1 is shown in FIG.
A net tube 19 as shown in FIG.
As described above, the net tube 19 is composed of a large number of monofilament filaments 15 having a substantially circular or elliptical cross section.
Are formed so as to intersect with each other in a stretchable manner, and are integrally formed as a flexible tube body.

As shown in FIG. 6, such a net tube 19 is wound in the longitudinal direction so as to form a roll 20. Therefore, the net tube 19 constituting the roll 20 is tightened in a flat flat shape, thereby forming fold curves 21 and 22 substantially parallel to two opposing sides of the flat tube, as shown in FIG. It has been impatient. That is, the filament 15 constituting the tube is bent at the folding curves 21 and 22 to have a bending habit.
When the bending curve 21 and 22 of the net tube 19 wound on the roll 20 did not have a sufficient bending habit, a sufficient bending habit was imparted by passing through a pair of sandwiching rollers after feeding. The folding curves 21 and 22 may be formed.

Therefore, the flat and flat net tube 19 having the folding curves 21 and 22 is fed out from the roll 20 in the longitudinal direction (net tube feeding step).

The net tube 19 fed from the roll 20 is used as a cutting means 2 having a cutting blade or a low-temperature fusing blade.
3 by the dissecting means 23.
2, and as shown in FIG. 3B, a half-fold net sheet 24 having front and back net sheet portions 2 and 3 extending in a half-fold state from the other folding curve 21 is formed (incision step). ). When tension is applied to the continuous body of the net tube 19 and the half-folded net sheet 24 in the transported state, the net is easily deformed to cause distortion as a whole. No intermittent drive rollers 25, 2 without tension
5 and intermittently transported. For this reason, the cutting means 23
The half-folded net sheet 24 cut by the above does not cause distortion, and as a result, the opposing edges 2b, 3b of the front and back net sheet portions 2, 3 cut along the folding curve 22 are aligned with each other in a straight line. Aligned.

As shown in FIG. 6, when the strip film 27 is fed from the roll 26 and passed through the intermittent driving roller 25, the back net sheet of the half-fold net sheet 24 is provided to provide the sealing piece 9. It is superposed on the outside of the opposing edge 3b of the part 3 (band-like film feeding polymerization step). As shown in FIG. 3B, the belt-shaped film 27 includes the adhesive layer 12 covered with the release film 11.
The belt-shaped film 27 fed from the roll 26 is intermittently driven without applying tension.
It is preferable to send to
It may be possible to pass through a step roll group 28 for intermittent feeding.

In order to provide the receiving piece 13, as shown in FIG.
When passing through the intermittent drive roller 25, the facing edge 2b of the front net sheet portion 2 of the half-fold net sheet 24
(A tape film feeding polymerization step).
The tape film 30 fed from the roll 29 is
Intermittent drive rollers 25, 2 without applying tension
5, it may be passed through a step roll group 31 for intermittent feeding as shown by a chain line in the figure.

Then, the half-folded net sheet 24 having passed through the intermittent drive roller 25 is intermittently transported from above and below with the tape film 30 and the band-shaped film 27 superposed thereon, and is heated by a heating plate 32 such as a hot plate, an ultrasonic wave or a high frequency electrode. 33, the receiving piece welding lines 14a and 14b and the sealing piece welding lines 10a and 10b as described above are formed and integrally joined (film welding wire forming step). At this time, a pressing force is applied to the front and back net sheet portions 2 and 3, whereby the ribbon portion 17 is pressed.
Is formed, and is surface-welded to the respective films 30 and 27 as described above.

Tape film 30 and strip film 27
When the band of the half-folded net sheet 24 is intermittently transported, the film strips 35a and 35b are continuously fed from the upper and lower rolls 34a and 34b, and are equally spaced in the longitudinal direction of the half-folded net sheet 24. And seal tape pieces 18a, 18a in the width direction of the front and back net sheets 2, 3.
(Seal tape piece arrangement step). As shown in FIG. 7, the film strips 35 a and 35 b are respectively fed by a predetermined amount by an intermittent feeding roller 36 and a floating roller 37, and are superposed on the front and back net sheets 2 and 3 during the intermittent stop, where the fusing blade or Shredding means 3 composed of a cutting blade or the like
8 to separate and form the sealing tape pieces 18a, 18a, and temporarily seal the sealing tape pieces 1 by a temporary welding means 39 comprising a heating body such as a hot plate or an ultrasonic or high-frequency electrode.
8a and 18a are temporarily welded to the front and back net sheets 2 and 3. Thereby, as shown in FIG. 4, the seal tape pieces 18a, 18a are arranged in the width direction of the front and back net sheets 2, 3 at equal intervals in the longitudinal direction of the continuous half-fold net sheet 24, and are temporarily welded 40. .

After that, when the half-folded net sheet 24 on which the sealing tape pieces 18a, 18a are temporarily welded 40 is intermittently transferred, as shown in FIGS. By the heating elements 41, 41, the sealing tape pieces 18a, 1
8a is sandwiched and pressed to form a side seal portion 6 (side seal step). As a result, as described above, the side seal portion 6 having a sandwich structure in which the ribbon portion 17 formed by the front and back net sheet portions 2 and 3 is welded and integrated between the pair of seal tape pieces 18a and 18a.
Therefore, as shown in FIG. 5, the side seal portions 6, 6 are spaced at equal intervals in the longitudinal direction of the continuous half-folded net sheet 24.
The half-folded net sheet 24 is further intermittently transferred in this state.

After that, the combined body of the half-folded net sheet 24, the band-like film 27 and the tape film 30, which is intermittently transferred, is separated by the dividing means 42 into the width W of the side seal portion 6.
The bag body 1 is obtained by cutting along the dividing line C located at the center of the bag. The bag 1 has a take-off conveyor 4
3 and is delivered to a predetermined position. In addition, the dividing means 42
Although a cutting cutter may be used, it is preferable to use a fusing blade.

[Second Embodiment of Bag Making Method] FIG. 8 shows a second embodiment of a method of manufacturing a breathable packaging bag according to the present invention, in which a net tube feeding step, an incision step, a strip film feeding polymerization. The step, the tape film feeding polymerization step, and the film welding wire forming step are the same as those in the first embodiment, and show a state in which the combined body of the half-folded net sheet 24, the band-shaped film 27, and the tape film 30 is intermittently transferred. ing.

Therefore, in the second embodiment, when the strip of the half-folded net sheet 24 in which the tape film 30 and the strip film 27 are integrated is intermittently transported, the film tape 35c is continuously transferred from a roll (not shown). Is inserted between the front and back net sheets 2 and 3 in the half-folded net sheet 24, and the front and back net sheets 2 and 3
Is temporarily welded 40a to the insertion portion of the film tape 35c, and cut along the opposing edges 2b, 3b of the front and back net sheets 2, 3 by cutting means (not shown). A seal tape piece 18 interposed therebetween is formed (seal tape piece arrangement step).

Thereafter, when the half-folded net sheet 24 temporarily interposed with the sealing tape piece 18 interposed therebetween is intermittently transferred,
The front and back net sheet portions 2 and 3 are sandwiched and pressed by a heating body (not shown) such as a hot plate or an ultrasonic or high-frequency electrode to form the side seal portion 6 (side sealing step). ). As a result, as described above,
The side seal portions 6 having a sandwich structure in which the ribbon portions 17 formed on each of the front and back net sheet portions 2 and 3 are welded and integrated on both surfaces of the seal tape piece 18 are formed, and in this state, the half-folded net sheet 24 is further intermittently formed. Be transported.

Thereafter, as in the first embodiment, the combined body of the half-folded net sheet 24, the band-like film 27 and the tape film 30 which is intermittently transferred is divided by the dividing means into the center of the width W of the side seal portion 6. The bag 1 is obtained by dividing along the dividing line C located at the position (1).

[0045]

According to the breathable packaging bag of the present invention, the bag 1 having both sides made of the net sheet portions 2 and 3 can be provided. Can be suitably maintained, and in the product storage state, instead of swelling in the radial direction as in the conventional net tubular bag, the bag body 1 swells on both front and back surfaces and slightly distorts the periphery, As a whole, the periphery can be held in a form close to the original rectangle, so that the appearance for displaying the goods is good.

In particular, since the front and back net sheets 2 and 3 form a stretchable mesh in which a large number of monofilament-shaped filaments 15 are crossed and integrated at a portion facing the article storage chamber 4, air permeability and air permeability are improved. At the same time, the product has good fit. In this regard, such a net material has conventionally been considered to be unable to be firmly welded, but according to the present invention, the side seal portions 6 are formed on both sides of the bag 1. The sealing tape piece 18 made of a synthetic resin film provided along the edge and the front and back net sheet portions 2 and 3 are integrally welded. Since the ribbon section 17 is deformed from the monofilament form to the flattened ribbon section 17, and the entire ribbon sections 17, 17 of the front and back net sheets 2, 3 and the sealing tape piece 18 are welded in a planar manner, sufficient mechanical strength is obtained. There is a remarkable effect that the strength is satisfied and a practical breathable packaging bag can be provided.

When such a bag 1 is made into a bag, if a band-like net sheet is half-folded in the band width direction as in the case of a conventional film bag, a monofilament-like filament is formed at the time of folding. Has a problem in that the net sheet formed from the above is freely expanded and contracted and easily deformed, and the opposed edges of the bent net sheet are not aligned with each other in a straight line, making it difficult to form a desired bag body. On the other hand, according to the production method of the present invention, not only the band-shaped net sheet but the tube-shaped net tube 19 is used, and the net tube 19 is provided with folding curves 21 and 22 substantially parallel to each other.
The front and back net sheet portions 2 and 3 in a half-fold state were provided by feeding out the flat net tube 19 in the longitudinal direction (net tube feeding step) and then cutting the flat net tube 19 along one fold curve 22. Half folded net sheet 2
4 (cutting step), the resulting half-folded net sheet 24 is not distorted, and the front and back net sheet portions 2 and 3 cut along the folding curve 22 are opposed to each other. The edges 2b, 3b are aligned and aligned with each other in a straight line, so that a subsequent process for forming a side seal by the seal tape piece 18 can be performed well, and high-quality and high-precision ventilation is achieved. It has a remarkable effect that a flexible packaging bag can be obtained.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a breathable packaging bag of the present invention, wherein (A) is a front view, (B) is a longitudinal sectional view, and (C) is an enlarged transverse sectional view.

FIG. 2 is an enlarged perspective view showing a part of a breathable packaging bag.

3A and 3B show a first embodiment of a method for producing a breathable packaging bag according to the present invention, wherein FIG. 3A is a perspective view showing a net tube, and FIG. 3B is a strip film and a tape film after cutting the net tube. It is a perspective view which shows the state which overlapped.

FIG. 4 is a perspective view showing a half-folded net sheet in a state in which seal tape pieces are temporarily welded in the first embodiment of the manufacturing method.

FIG. 5 is a perspective view showing a half-folded net sheet in a state where a side seal portion is formed and a divided bag body in the first embodiment of the manufacturing method.

FIG. 6 is an explanatory view illustrating a bag making machine for carrying out the first embodiment of the manufacturing method.

FIG. 7 is a diagram illustrating a bag making method for performing the first embodiment of the manufacturing method .
It is an expanded sectional view showing a side seal device in a machine .

FIG. 8 is a perspective view showing a second embodiment of the method for manufacturing a breathable packaging bag according to the present invention, showing a half-folded net sheet in a state where a side seal portion is formed and a divided bag body. .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bag 2 Front net sheet part 3 Back net sheet part 2a, 3a Opening edge 2b, 3b Opposite edge 4 Article storage room 6 Side seal part 8 Opening 9 Sealing piece 13 Receiving piece 15 Monofilament-like filament 16 Thread Part 17 Ribbon part 18, 18a Seal tape piece

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B65D 30/06 B31B 1/64 B31B 23/64

Claims (5)

(57) [Claims] An air permeability formed by forming side seal portions which are located on both side edges of a bag body in which front and back net sheets made of synthetic resin are disposed with an article storage room interposed therebetween and which welds both net sheets together. a packaging bag, the front and rear net seat constitute a large number of monofilaments shaped stretchable mesh the striatum was allowed integrally intersects
At the same time, the filament was flattened at the side seal portion.
A ribbon portion is formed, and the side seal portion is formed by integrally welding a seal tape piece made of a synthetic resin film provided along both side edges of the bag body and the ribbon portion of the front and back net sheet portions. And a breathable packaging bag. 2. A method according to claim side seal portion, characterized by comprising been allowed integrally welded in a state sandwiching the ribbon portion of the front and rear net seat between a pair of sealing tape pieces 1
A breathable packaging bag according to claim 1. 3. The breathable packaging bag according to claim 1 , wherein the side seal portion is welded and integrated with the sealing tape piece sandwiched between the ribbon portions of the front and back net sheet portions. . 4. The method of claim 1, 2 or 3 sides net seat is characterized by comprising folded along the bottom of the bag body
A breathable packaging bag according to claim 1. 5. A synthetic resin net tube having a stretchable mesh formed by intersecting and integrating a large number of monofilament-like filaments into a flat flat shape having substantially parallel folding curves in the longitudinal direction. A net tube feeding step; a cutting step of forming a half-folded net sheet having a half-folded front and back net sheet portion by cutting a flat net tube along one of the folding curves; A side sealing step of arranging a seal tape piece in the width direction of the net sheet at a predetermined interval in the longitudinal direction of the sheet, and forming a side seal portion by welding and integrating the seal tape piece and the front and back net sheet portions. And a dividing step of dividing the side seal portion along a dividing line in the width direction of the net sheet. Manufacturing method of packaging bag.