JP2001055244A - Air-permeable packaging bag, and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the whitening phenomenon caused by small water drops generated on an inner surface of a printed film when a vegetable is packaged by executing the autifog treatment on the inner surface of the printed film in a synthetic resin air-permeable packaging bag with one side formed of the printed film and the other side formed of a net sheet. SOLUTION: A polyethylene net sheet 3 is laminated on an inner surface side of a polypropylene resin, substantially rectangular bag film 2 with an outer surface side printed and an inner surface side processed with autifog treatment, and side bonded edges 4, 4 and a bottom welding edge 5 located therearound of 5-20 mm in width with the bag film 2 and the net sheet 3 heat- bonded to each other to form an article storage part. In addition, the bag film 2 is provided with a sealing piece 8 extended over an opening edge 7 of the net sheet 3 to constitute an opening part 6 of the side bonded edge 4, and a pressure sensitive adhesive coated layer as a sealing means 9. The bottom part of the bag body 1 holds a bottom edge of the net sheet 3 by an extended return piece 10 of the bag film 2, and is heat-bonded by the welding edge 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas permeable packaging bag which can be sold over the counter in a state in which products which require air permeability such as fresh fruits and vegetables are stored.

[0002]

2. Description of the Related Art Conventionally, small vegetables such as green soybeans and okra,
It is desirable that small fruits such as kumquat (collectively referred to as fresh fruits and vegetables including such vegetables and fruits) be sold in stores at a certain amount in a packaging bag. Conventionally, many monofilaments are crossed and integrated. It is housed in a packaging bag consisting of a net tube having an elasticized elastic mesh. That is, while cutting the net tube to a predetermined length,
One end is bundled and welded to form a bag with a bottom. After the fruits and vegetables are stored in the bag, the paper header is stapled to close the opening of the bag. However, since such a packaging bag is entirely formed of a net, it is not possible to print and display information on a product. For print display, information is printed and displayed on the paper header portion stapled, but there is a drawback that the header tends to come off, and the print space is small and sufficient information cannot be displayed. Usually, packaging bags that can be sold over the counter in a state where various small items are stored constitute a substantially rectangular bag body by fusing and welding a front film and a back film made of a synthetic resin film.
A hanging header is provided at the top of the bag. Therefore, it is possible to arbitrarily print the front and back film surfaces,
There is no shortage of space for displaying product information. 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 sealed, the air permeability is poor, and the freshness is reduced early. Since fresh fruits and vegetables maintain their freshness by respiration, if freshness is impaired, freshness will be reduced at an early stage. The air-permeable packaging improved in this point is disclosed in
It is known from JP-A-1-130089. In this breathable bag, although the back surface of the bag is a net sheet and is almost completely open to the atmosphere, fine dew deposits on the inner surface of the resin film in the bag and the bag surface Becomes white and opaque. Such a phenomenon is completely unexpected for a breathable bag whose back surface is made of a net sheet and is completely open. That is, even in the case of a breathable bag, high moisture generated by the physiological respiration of the stored fresh fruits and vegetables is formed on the inner surfaces of the fruits and the bag film and reaches a dew point in a partially closed space, and dew occurs. It is considered something. In any case, in the state whitened by such fine water droplets, the fresh fruit vegetables contained therein are not visible at all, so that the appearance of the products is poor and the willingness to purchase is reduced. Also, water droplets generated on the inner surface of the packaging bag
In some cases, it becomes a cultivation pond for microorganisms, causing fruit fruits to rot or emit a bad smell from the breathable package.

[0003]

According to the present invention, when forming a packaging bag for fresh fruits and vegetables, one surface of the bag body is made of a synthetic resin bag film and the other surface is made of a synthetic resin net sheet. In addition, the excessive flexibility of the net sheet is suppressed and improved by polymerization with the synthetic resin printing film, and the breathability of the net sheet in the air-permeable packaging bag is still improved even in a humid condition. An object of the present invention is to provide a breathable packaging bag capable of preventing a whitening phenomenon due to fine water droplets generated on the inner surface of a printing film, and an efficient manufacturing method thereof. In particular, in the manufacturing method, the welding between the synthetic resin film and the net sheet is welding between the film surface and the filament of the net sheet, and it is necessary to solve the problem that the welding strength is low because the welding area is small.

[0004]

SUMMARY OF THE INVENTION According to the present invention, even if the whitening phenomenon due to water droplets occurs even if the net sheet has air permeability, the antifogging treatment is applied to the inner surface of the synthetic resin printing film to achieve the whitening. The inventors have found that the phenomenon can be prevented, and based on this finding, have completed the present invention. Further, in order to improve the welding strength between the synthetic resin printing film and the net sheet, in the case of welding with a continuous heat seal roller, the thickness is 2 mm or more, preferably 3 mm or more.
The welding using the heat seal roller having the above width improves the welding strength, while the welding of the side edge of the bag by thermocompression on a thermocompression table performed intermittently has a width of 10 to 40 mm, preferably 20 to 40 mm. After performing the thermocompression bonding with a width of 30 mm, the welding width of the side edge is formed to 5 to 20 mm, preferably 10 to 15 mm by a method of cutting the center of the thermocompression bonding to improve the welding strength of the side edge. It is characterized by the following. That is, the present invention includes the following items. (1) A bottom of a substantially rectangular laminate formed by superimposing a synthetic resin net sheet on the surface of a substantially rectangular synthetic resin print film having no printed layer, and a bottom portion of a bag formed by welding the print film and the net sheet. A bag having side edges formed on both sides of the laminate by a thermocompression welding edge having a width of 5 to 20 mm, and having an opening around an upper periphery of the laminate. A breathable packaging bag, characterized in that the inside of the bag inside the printed film of the bag body is subjected to anti-fogging treatment. (2) The ventilation according to (1), wherein the bottom of the bag is formed by folding the lower edge of the synthetic resin printing film over the lower edge of the synthetic resin net sheet and welding the folded portion by heat sealing. Packaging bag. (3) The opening portion of the breathable packaging bag described in (1) has a sealing piece integrally extended from the synthetic resin printing film side of the opening edge, and the outer surface of the opening edge on the net sheet side. A tape-like film made of a synthetic resin of the same type as the net sheet is polymerized, and the side edges on both sides of the tape-like film and the net sheet at the opening edge are welded to form an opening welding edge. A breathable packaging bag characterized by being a bag body having a mechanism for abutting a tip of a sealing piece to seal an opening via a pressure-sensitive adhesive layer. (4) The synthetic resin printing film is made of polypropylene, and the synthetic resin net sheet is made of polyethylene.
The breathable packaging bag according to (1), (2) or (3). (5) Intermittent one-pitch by polymerizing a long polypropylene printed film sheet having an antifogging surface and a long polyethylene net sheet that is continuously fed out, and damper rolls in the middle of the polymerization. In the method of producing a bag body by cutting the side edge of the bag body by converting it into movement, in the first step, a long polyethylene net sheet is polymerized on the anti-fog surface of the long polyethylene print film sheet. To form a continuous laminate of the net sheet and the printing film continuously, and in a second step, the bottom side peripheral edge of the continuous laminate is welded by a heat sealing roller, and then, in a third step, an intermittent one pitch Moving the long laminate, while checking the print pattern of the printing film with the photoelectric tube, supplying the long laminate on the side edge welding table in synchronization with the print pattern, and having a width of 10 to 40 mm. After forming a welding side edge having a width of 10 to 40 mm at a predetermined position of the printed pattern by thermocompression bonding using a hot press, in a fourth step, the welding side edge is supplied on a cutting table by intermittent one-pitch movement. A method for producing a breathable packaging bag, characterized by cutting a substantially central line of the bag. (6) Intermittent one pitch by polymerizing a long polypropylene print film sheet having an antifogging surface and a long polyethylene net sheet which is continuously fed out by a damper roll group on the way. In the method of manufacturing the bag body by converting the movement into the side body and cutting the side body of the bag body, in the first step, a polyethylene film tape having a width of 15 to 50 mm is polymerized on the edge of the long polyethylene net sheet. By fixing both side edges of the polyethylene film tape to the edge of the net sheet by heat sealing to form a net sheet side opening edge, in a second step,
The net sheet having the opening edge is continuously aligned with the anti-fog surface of the printing film, the bottom side thereof is aligned, and a long laminated body obtained by continuously polymerizing the printing film so that the edge of the printing film protrudes from the opening edge of the net sheet side. Forming, in a third step, forming a bottom welding edge by hot roll or thermocompression bonding the bottom side welding of the laminate,
In the fourth step, the long laminated body intermittently moved by one pitch is supplied with the long laminated body on the side edge welding table in synchronization with the printed pattern while checking the printed pattern of the printed film with the photoelectric tube, and
After forming a welding side edge having a width of 10 to 40 mm at a position of a predetermined printing pattern by thermocompression bonding with a hot press having a width of 40 mm, further, in a fifth step, supplying the cutting side by one pitch movement on a cutting table, A method for producing a breathable packaging bag, comprising cutting a substantially central line of a welding side edge.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A substantially rectangular synthetic resin printing film used for a breathable packaging bag of the present invention is provided with information relating to advertisement and explanation of goods and printing of a picture or pattern. This printing, in the case of a single-layer film, has a print layer on the outer surface, and since the printing process is performed after the anti-fog treatment, when the print layer is on the inner surface side of the bag, it was applied to the inner surface of the film. The antifog property is shielded by the print layer and loses the antifog effect. In addition, water droplets are likely to be generated on the printing surface due to water repellency. When the synthetic resin printing film is a laminate film, the printing layer is desirably applied inside the laminate. In the printing pattern of the long synthetic resin printing film used in the manufacturing method of the present invention, the printing pattern characters are periodically repeated. The anti-fogging treatment of the present invention includes a method of kneading the anti-fogging composition with the raw resin of the synthetic resin film and a method of coating the film surface with the anti-fogging composition. The method of kneading the antifogging composition with the resin raw material has an advantage that the antifogging performance is maintained, but generally has a disadvantage that the antifogging composition bleeds on the film surface because the affinity between the resin and the antifogging composition is low. is there. The antifogging composition used in the present invention can be used without any particular limitation as long as it has a function of preventing water droplets from being generated on the film surface. Usually, as the antifogging agent, there is a composition containing a surfactant, and any known surfactant such as a cationic or anionic surfactant and a nonionic surfactant can be used. When a surfactant is used, any of a method of kneading with a raw material resin and a method of applying the surfactant to a film surface can be used. The surfactant exerts an antifogging effect by reducing the surface tension of the water droplet to prevent the formation of the water droplet. As another antifogging composition, a method of applying an inorganic colloid sol, such as silica, alumina, or titanium oxide, having no problem from food hygiene in order to form a fine uneven surface on the film surface can be used.
In this case, for example, a roughened ink containing inorganic fine particles used for a roughening treatment of the film surface can be preferably used. Although this method has a drawback that slightly reduces the transparency of the bag film, this drawback is not a problem in most cases because the coating layer is thin. The method using an inorganic colloid sol or a roughened ink is a method in which the formation of water droplets is physically inhibited by the shape of the film surface. Further, a hydrophilic water-insoluble substance, for example, a substance such as a polyhydric alcohol condensed fatty acid ester is applied to modify the film surface into a hydrophilic surface having good wettability to water, and convert water droplets into a liquid stream. Water droplets can be prevented. The antifogging treatment used in the present invention can be used in combination with one or more of the above antifogging treatment methods. In particular, it is desirable to use two or more antifogging means in combination, since a reliable antifogging effect can be obtained. As the printing film used in the present invention, a single layer or a laminated film can be used. The printing film used in the present invention is printed after the antifogging treatment, which is convenient from the viewpoint of the manufacturing process. Therefore, printing is performed on the outer surface of the bag, not the inner surface of the bag where the anti-fog treatment surface is provided. Printing on an inner surface having an anti-fogging treatment loses the anti-fogging property because the anti-fogging surface is shielded.

When a laminated film is used, it is desirable to provide a printing layer between laminations. Then, an anti-fog treatment is applied to the inner surface of the film. As an example of the antifogging composition of the coating system used in the present invention, 1 part by weight of colloidal silica, 2 parts by weight of colloidal alumina, and 0.1 part by weight of an anionic surfactant are mixed with 100 parts by weight of water. Then, if desired, a viscosity modifier for improving the coating performance can be added, and the film can be coated on the film surface by spray coating. Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. The main technical problems of the present invention are the following two points. A first problem is to prevent the formation of water droplets on the inner surface of the bag film by the above-described anti-fog treatment. A second object is to increase the strength of the welding between the bag film and the net sheet at the side edge of the bag body and the bottom of the bag body and the welding between the net sheet and the film tape at the opening edge. In the latter welding of the net sheet and the film, the welding area on the net sheet side is the filament of the net sheet, the welding between the filament surface and the wire, and the welding strength is much lower than the welding strength between the films. . In the present invention, in the welding of the side edge of the bag, the width of the welding is widened to increase the welding strength, and the welding of the tape at the opening edge is made completely the same in resin material to increase the welding strength. In the first embodiment shown in FIG. 1, a bag 1 is formed by polymerizing a polyethylene net sheet 3 on an anti-fog surface of a printed bag film 2 made of polypropylene resin disposed on one side. And net sheet 3
An article storage part is formed between the side parts, and side welding edges 4 and 4 and a bottom welding edge 5 are provided around the article storage part for mutually welding the bag film 2 and the net sheet 3. The resin material forming the bag film 2 and the resin material forming the net sheet 3 are made of a polyolefin resin that can be welded to each other. The printed layer of the printed bag film 2 is
In the case of an outer surface or a laminated film, it is present in the middle of the lamination of the film. The inner surface of the bag film 2 is subjected to an anti-fog treatment. In the anti-fogging treatment of this embodiment, a roughening ink which is a vehicle composition for ink in which silica powder used for the roughening treatment is dispersed is coated by a printing method. In this case, if a surfactant is added to the dispersion of the roughened ink, the antifogging effect is further improved. The transparency is slightly reduced by the silica powder in the roughened ink, but if a completely transparent bag film is required, an ink vehicle containing a small amount of a surfactant or a hydrophilic polymer in place of the silica powder is used. The entire surface of the printing film can be printed with the composition. The net sheet 3 and the bag film are not particularly limited as long as they are thermoplastic resins, but are preferably polyolefin resins from the viewpoint of bag workability. Many net sheets are usually made of polyethylene and are commercially available. On the other hand, the bag film is preferably made of polypropylene from the viewpoint of transparency. When the polyethylene film is welded to the polyethylene net sheet at the side edges by hot pressing and crimping, the width of the side welding edge can be about 3 mm.However, when the polypropylene film is welded to the polyethylene net sheet, The welding edge is preferably 5 mm or more, more preferably 10 mm or more. If the width is narrow, the welding strength is low, and the packaging bag may be damaged from the welding edge. Also, if the welding width is too wide, the capacity of the storage portion of the bag relative to the size of the bag is reduced, so that the width of the welding edge is preferably 20 mm or less, and more preferably 15 mm or less. It is necessary to increase the pressing force of the press during this heat welding.

The bag film 2 is provided with a sealing piece 8 extending beyond an opening green 7 of the net sheet 3 constituting the opening 6 of the side welding edge 4, and the sealing piece 8 is provided with a pressure-sensitive adhesive layer. Are provided as sealing means 9. In the case of the breathable packaging bag of the present invention in which the sealing piece is not provided, the sealing is performed by thermocompression bonding after storing the product. In some cases, it is possible to seal with a stapler. In addition, the bottom of the bag 1 is provided with a folded piece 10 obtained by folding the extension of the bag film 2, the bottom green of the net sheet 3 is sandwiched between the bag film 2 and the folded piece 10, and sandwiched by the bottom welding edge 5. It is welded in a shape. When the welding method of FIG. 1 is used, even if the welding width is narrow, the welding is performed firmly. In the breathable bag of the present invention, as a mode in which the process is simple, the bottom is not formed in such a sandwich structure, and the peripheral edge is simply 5 to 20 mm, preferably 10 to 15 mm, like the side welding edge.
Welding width. In this manner, in the breathable bag of the present invention, the side welding edge 4 and the bottom welding edge 5 are provided at positions other than the opening 6 of the article storage section, and the side welding edges 4 and 4 are provided on both sides. The bottom welding edge 5 constitutes the side welding edge, and the bottom welding edge 5 constitutes the bottom welding edge. A synthetic resin tape 11 is superposed on the outer surface of the opening green 7 of the net sheet 3, and two opening edge heat seals 12, 12 for welding the tape 11 and the opening green 7 to each other are attached to the tape 11. Both sides are provided in parallel along the green. The resin material forming the tape 11 and the resin material forming the net sheet 3 are:
It is a homogeneous resin that can be welded to each other. In this case, since the synthetic resin tape 11 is welded by the opening edge heat seals 12 and 12 by heat sealing with a narrow welding width, when the net sheet is made of polyethylene, the tape 11 may be a polyethylene film. Especially desirable. As shown in the partial enlarged view of FIG. 1 (B), the net sheet 3 has a stretchable mesh in which a large number of monofilaments 13 having a substantially circular or elliptical cross section are crossed and integrated. I do. In the illustrated example, the sealing means 9 comprises an adhesive layer 16 and a release tape 17 covering the adhesive layer 16. Therefore, after storing products such as fresh fruits and vegetables in the article storage section through the opening 6, the release tape 1
7 is peeled off and the sealing piece 8 is folded over the opening green 7,
The adhesive layer 16 is adhered to the tape 11, and the opening 6 is closed by the sealing piece 8. FIG. 2 shows a bag making method according to the first embodiment. The bag film 2 is continuously fed from a roll 2a wound with a belt-like film, and passes through a step roll group 18 on the way. The bag is transported intermittently at one pitch interval of the width of the bag. In the manufacturing method of the present invention, the processing steps are divided before and after the stepped roll group 18 in the middle of the flow of the band-shaped film to be the bag film 2. First, a sealing means 9 is provided in advance on the edge of the bag film 2 of FIG. 2 by continuously adhering a release paper tape with a pressure-sensitive adhesive. As a separate system from the bag film, the net sheet 3 is pulled out from a net sheet roll 3a around which a belt-shaped net sheet is wound, and is superposed on the tape 11 fed from a wound tape roll 11a. The above-mentioned opening edge heat seals 12 and 12 are formed by the heat sealing means 19 using two heat rolls, and the tape 11
Is welded to a predetermined portion of the net sheet 3. If the net sheet 3 is made of polyethylene and the tape 11 is also made of polyethylene, the softening melting point of the resin is low and the resin is of the same quality. Easy welding,
Its welding strength is also large.

Therefore, it is desirable that both the net sheet 3 and the tape 11 be made of polyethylene in the manufacturing process. When the tape 11 is welded and fixed to one end edge of the net sheet 3, the length of the net sheet 3 in the longitudinal direction is fixed, the dimensional stability of the net sheet 3 is dramatically improved, and the handling is easy. Become. Since the net sheet 3 is net-like, it expands and contracts greatly in the vertical and horizontal directions, so that the sheet shape is extremely unstable. Therefore, when the tape 11 is welded to the net sheet 3, if a tension is applied in the longitudinal direction of the net sheet 3, the width direction is contracted. At this time, in order to maintain the predetermined lateral width of the net sheet 3, the tape 11 is superimposed on the tape 11 in a state where tension is not applied to the net sheet 3, and the tape 11
It is necessary to carry out welding. For this purpose, tension is applied to the tape 11 from the downstream of the heat roll of the heat sealing means 19 to apply the tension to the net sheet 3 and the tape 1.
You need to draw one. And tape 1
After 1 is welded, the net sheet 3 does not expand or contract in the vertical direction, so that it can be handled according to a normal film sheet. Next, the net sheet 3 provided with the tape 11
Is superimposed on the bag film 2 before the step roll, where the side green of the bag film 2 is folded by the folding means 20 to form the above-mentioned folded piece 10, and the net sheet is formed between the bag film 2 and the folded piece 10. Insert the side green of No. 3. Then, the bottom welding edge 5 described above is formed by the sealing means 21, and the bag film 2, the net sheet 3 and the folded piece 10 are welded in a sandwich shape. In order to facilitate understanding, a continuous body of the net sheet 3 provided with the tape 11 and a continuous body of the bag film 2 provided with the sealing means 9 on one side green and the folded piece 10 on the other side green are disassembled. Is shown in FIG. As described above, when one edge of the net sheet 3 is welded to the tape 11 and the other edge is welded by folding welding of the bag film 2, the longitudinal and lateral elasticity of the net sheet 3 disappears. As a result, the vertical and horizontal shapes of the net sheet 3 are stabilized. In the present invention, the edge of the net sheet 3 and the edge of the bag film can be welded and fixed simply by thermocompression bonding with a width of 3 mm or more without folding and welding the bag film 2. The operation of forming the bottom welding edge performed by the folding method or the thermocompression bonding method in the present invention includes:
Either before or after the step roll group can be carried out continuously or intermittently. Further, in the present embodiment, instead of welding with the tape 11, the edge of the net sheet 3 and the edge of the bag film are fixed by welding instead of welding with the tape 11 as the step of preventing the net sheet 3 from expanding and contracting in the vertical direction. It can be carried out. This embodiment is used not only in the embodiment of the present invention in which the tape 11 is not used but also when the tape 11 is used.
Before the opening edge heat seal 12, the bottom welding edge can be welded first. In this case, it is necessary for the operation to be performed before the step roll group 18. Now, in FIG. 2, the bag films 2 welded to each other by the bottom welding edge 5 are shown.
The continuous band of the net sheet 3 is stopped at the position of the thermocompression bonding means 22 by intermittent transfer according to a predetermined width dimension of the bag 1 to be formed, that is, movement by one pitch unit. A welding edge twice as wide as the side welding edge 4 is formed by thermocompression bonding. When the welding edge having a width twice that of the side welding edge 4 formed here is cut by the cutting means 23 provided at a position stopped by the next one-pitch movement, the bag body having the side welding edge 4 on both sides. 1 is obtained and delivered to a predetermined position by the take-off conveyor 24. The cutting means 23 used in the present invention comprises:
Either a cutting cutter or a fusing blade can be used, but fusing of the fusing blade is desirable in that the end of the filament of the net sheet 3 is not released.

[0009]

According to the present invention, one surface of the bag body 1 is formed by the synthetic resin bag film 2 and the other surface is formed by the synthetic resin net sheet 3. It has the advantages of securing space for displaying product information, preventing the occurrence of fine water droplets on the inner surface of the bag film, maintaining the freshness of the product, and preventing the whitening of the bag film and motivating the purchase of the product. is there.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention, in which (A) is a perspective view showing the entirety, and (B) is a perspective view showing a partly enlarged view.

FIG. 2 is an explanatory process diagram showing a method for manufacturing a packaging bag according to an embodiment of the present invention.

FIG. 3 is a reference perspective view showing a continuous body of a bag film and a net sheet in the course of the manufacturing method, in a mutually exploded manner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bag body 2 Bag film 3 Net sheet 3a Net sheet roll 4 Side welding edge 5 Bottom welding edge 6 Opening 7 Net sheet side opening edge 8 Sealing piece 9 Sealing means 10 Folding piece 11 Tape 11a Tape roll 12 Opening edge heat seal DESCRIPTION OF SYMBOLS 13 Monofilament 16 Adhesive layer 17 Release tape 18 Step roll group 19 Heat sealing means 20 Folding means 21 Sealing means 22 Thermocompression bonding means 23 Cutting means 24 Pick-up conveyor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E035 AA11 BA08 BB02 BC02 BD10 CA07 3E064 AA05 BA26 BA30 BA60 BC18 BC20 EA04 EA18 EA30 HA06 HB05 HD07 HE01 HF06 HG02 HN02 3E067 AA11 AB08 AB09 BA12A BB15A04 GB30 BC30 GBA

Claims (6)

[Claims] 1. A bag formed by welding a printing film and a net sheet at the bottom of a substantially rectangular laminate formed by superimposing a synthetic resin net sheet on a surface of a substantially rectangular synthetic resin printing film having no printed layer. A bag having a body bottom portion, a bag body side edge formed by a thermocompression welding edge having a width of 5 to 20 mm on both side edges of the laminate, and an opening around an upper part of the laminate. A breathable packaging bag, characterized in that the inside of the bag of the printed film of the bag body is subjected to anti-fogging treatment. 2. The ventilation according to claim 1, wherein the bottom of the bag is formed by folding a lower edge of a synthetic resin printing film over a lower edge of a synthetic resin net sheet and welding the folded portion by heat sealing. Packaging bag. 3. The opening of the breathable packaging bag according to claim 1,
It has a sealing piece integrally extended from the synthetic resin printing film side of the opening edge, and is formed by polymerizing a synthetic resin tape film of the same type as the net sheet on the outer surface of the opening edge on the net sheet side. Welding the side sheet on both sides of the tape-shaped film and the net sheet of the opening edge to form an opening welding edge, abutting the tip of the sealing piece on the opening welding edge, and opening the opening via a pressure-sensitive adhesive layer. A breathable packaging bag, which is a bag having a closing mechanism. 4. A breathable packaging bag according to claim 1, wherein the synthetic resin printing film is made of polypropylene, and the synthetic resin net sheet is made of polyethylene. 5. A continuous printed polypropylene film sheet having an antifogging surface which is continuously fed and a long polyethylene net sheet which is continuously fed are polymerized and intermittently interposed by a group of damper rolls. In the method of manufacturing the bag body by cutting the side edge of the bag body, in the first step, a long polyethylene net sheet is coated on the anti-fog surface of the long polyethylene print film sheet. Polymerization is performed to continuously form a long laminated body of the net sheet and the printing film, and in a second step, the bottom side peripheral edge of the long laminated body is welded by a heat seal roller. While checking the printed pattern of the printed film with the photoelectric tube, the long laminated body was moved on the side edge welding table while checking the printed pattern of the film by 10 pitches, and the long laminated body was supplied on the side edge welding table, and 10 to 40 m in length. After forming a welding side edge having a width of 10 to 40 mm at a predetermined position of the printed pattern by thermocompression bonding with a hot press having a width of m, further in the fourth step, intermittent one-pitch movement is supplied onto the cutting table, A method for manufacturing a breathable packaging bag, comprising cutting a substantially central line of the welding side edge. 6. A long continuous printed polypropylene film sheet having an antifogging surface and a continuous long polyethylene net sheet continuously fed are polymerized, and intermittently formed by a group of damper rolls on the way. In a method of manufacturing a bag body by cutting the side edge of the bag body by converting to a one-pitch movement, in the first step, a polyethylene film tape having a width of 15 to 50 mm is polymerized on the edge of a long polyethylene net sheet. Then, both side edges of the polyethylene film tape are fixed to the edge of the net sheet by heat sealing to form an opening edge on the net sheet side, and in the second step, the net sheet having the opening edge is subjected to anti-fog of a printing film. A long laminated body formed by superimposing the bottom of the printing film so that the edge of the print film protrudes from the opening edge of the net sheet side, In the third step, the bottom side welding of the laminate is formed by a hot roll or thermocompression bonding to form a bottom welding edge, and in the fourth step, a long laminate intermittently moved by one pitch is printed with a photoelectric tube. While checking, the long laminate was supplied on the side edge welding table in synchronization with the printed pattern, and 1
After forming a welding side edge having a width of 10 to 40 mm at a position of a predetermined printing pattern by thermocompression bonding with a hot press having a width of 0 to 40 mm, the fifth step is performed on a cutting table by one-pitch movement. A method for producing a breathable packaging bag, characterized by cutting a substantially central line of the welding side edge.