JPH0811585B2 - Packaging bag and laminated film used for the packaging bag - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging bag used for packaging foods and the like in a hermetically sealed state. More specifically, among a plurality of synthetic resin layers, at least one pair of synthetic resin layers adjacent to each other are heat-treated. The present invention relates to a packaging bag obtained by heat-sealing a laminate film made of a synthetic resin material that cannot be fused in a bag shape, and a laminate film used therein.

[0002]

2. Description of the Related Art In this type of packaging bag, if a large amount of gas is simultaneously enclosed in the packaging bag at the time of packaging, the bag may burst when an external force acts on the bags due to multi-stage stacking or the like. , The bag may burst if steam is generated due to the heating of the packaged product enclosed in the packaging bag, or if the cooling solid carbon dioxide enclosed with the packaged product is vaporized. There is. However, if the ventilation holes are simply formed through the laminated film that constitutes the packaging bag, even if the air and the gas or vapor generated inside the package after packaging can be released to the outside, the penetration formation There are inconveniences such as the inclusion of foreign matter from the created ventilation holes or the oxidation of the packaged object. So, in the past,
As shown in FIG. 19, a vent pipe 51A formed flat with a synthetic resin film is provided at the inlet 50 of the packaging bag whose periphery is heat-sealed into a bag shape, leaving the inlet 50 of the packaged object, A check valve 51, which is composed of a synthetic resin film piece 51B having one end adhered to one of the inner surfaces of the trachea 51A facing each other and the other end closely adhered to the other inner surface, is inserted, and the check valve is also inserted. 51 and the inlet 50 of the packaging bag are heat-sealed together, so that the inner surface of the ventilation pipe 51A and the film piece 51
It is proposed that the fluid in the bag is discharged to the outside through an air passage formed between the other end of B and the other end (for example, Japanese Utility Model Publication No. 63-67443, Japanese Utility Model Publication 6).
3-59838).

[0003]

In the conventional packaging bag,
The vent pipe 51A is formed by flattening a synthetic resin film, and the film piece 51 provided in the vent pipe 51A.
Since B adheres closely to the inner surface, it has the advantage that foreign substances can be prevented from entering from the outside while discharging the fluid in the bag to the outside, but in packaging, it is made of synthetic resin film in addition to the packaging bag. Since the check valve 51 must be prepared, and a step of heat-sealing the check valve 51 with the check valve 51 inserted and held in a predetermined position of the loading port 50 of the packaging bag is added, particularly, the object to be packaged is There is a problem that the structure for automation in the case of continuously filling and packaging is extremely complicated and the manufacturing cost is increased. Moreover, since the mounting position of the check valve 51 is limited to the insertion port 50 of the packaging bag, the form of the packaging bag is easily restricted. The present invention has been made in view of the above circumstances, and an object thereof is to smoothly discharge the fluid in the bag to the outside as necessary while normally ensuring high airtightness. A packaging bag that can
It is advantageous in that it can be manufactured advantageously in terms of manufacturing cost and automatic packaging, and the fluid discharge position can be freely set according to the form of the packaging bag.

[0004]

In order to achieve the above object, in the present invention, among a plurality of joined synthetic resin layers,
At least one set of adjacent synthetic resin layers in a packaging bag formed by heat-sealing a laminate film composed of a synthetic resin material that cannot be heat-sealed to each other, among the synthetic resin layers of the laminate film, A part of the non-heat-bondable synthetic resin layer is formed with a non-adhesive part capable of exposing a ventilation path leading to the outside of the bag, and the synthetic resin layer on the bag internal space side corresponding to the non-adhesive part is In the innermost synthetic resin layer facing the bag inner space, which forms a communication port for communicatingly connecting the ventilation passage and the bag inner space, the periphery of the communication port or a part in the vicinity thereof and the bag inner space Is heat-fused to the portions facing each other with a part of the above sandwiched therebetween. Further, as described in claim 2, the communication port may be a cut formed in the synthetic resin layer on the bag inner space side corresponding to the non-adhesive portion. Further, as described in claim 3, as the laminate film, an adhesive agent that joins two base material films that cannot be heat-sealed to each other among base material films made of synthetic resin that are joined in a plurality of layers. The non-adhered portion may be formed to have a non-adhesive portion capable of exposing the ventilation path communicating with the outside of the bag.

[0005]

[Function] Among a plurality of synthetic resin layers constituting the laminate film, the non-adhesive portion formed between the synthetic resin layers that cannot be heat-sealed to each other exposes the ventilation path leading to the outside of the bag. Even when the periphery of the packaging bag is sealed by heat fusion in a crossing state, the ventilation path exposed at the non-adhesive portion is not closed. Therefore, even if the non-adhesive portion is provided at any position of the packaging bag, the predetermined air passage can be surely exposed. Moreover, in the innermost synthetic resin layer of the laminate film facing the bag inner space, a part of the peripheral edge of the communication port or the vicinity thereof and a part facing each other with a part of the bag inner space sandwiched therebetween are heat-melted. Therefore, when the internal pressure of the packaging bag rises due to external factors such as ambient temperature and external pressure, the non-heat-sealed facing parts located around the heat-sealed facing parts are outside. It bulges and deforms in one direction, the communication port formed in the synthetic resin layer on the bag internal space side corresponding to the non-adhesive part opens greatly, and the fluid in the bag internal space is passed through the ventilation path communicating with the communication port. Can be discharged to the outside. Moreover, in the normal state where the internal pressure of the packaging bag is below the set value, the non-adhesive portions forming the communication port and the air passage are in close contact with each other, so that the inside of the bag is maintained in a highly airtight state.

[0006]

Therefore, since the ventilation path and the communication port for connecting the ventilation path and the inner space of the bag are formed in the laminated film itself, as in the conventional case, in addition to the packaging bag, the reverse direction made of the synthetic resin film is used. Since there is no need to prepare a stop valve, and no process to attach it to the inlet of the packaging bag, a packaging bag with both a degassing function and an airtight function can be manufactured in terms of manufacturing cost and automatic packaging. It can be advantageously manufactured. Moreover, since the fluid discharge position can be freely set according to the form of the packaging bag, the degree of freedom in designing the packaging bag can be increased. Further, when the configuration described in claim 2 is adopted, the communication port can be easily processed in the continuous manufacturing process of the laminated film, and the adhesiveness of the communication port at the normal time can be improved. There is an effect that the airtight performance can be improved. Furthermore, when the laminate film described in claim 2 is used, a desired ventilation path can be freely exposed by considering the non-application position of the adhesive during the continuous manufacturing process of the laminate film. Since it can be implemented by simply modifying the existing equipment, there is an effect that the manufacturing cost can be reduced.

[0007]

[Embodiment] [First Embodiment] The packaging bag shown in FIGS.
As shown in FIG. 6, the synthetic resin layer 1 laminated in two layers.
A and 1B are formed by heat-sealing a laminated film 1 made of nylon and polyethylene that cannot be heat-sealed together into a bag shape. Specifically, a nylon base film (which becomes one synthetic resin layer) 1A and a polyethylene base film (which becomes the other synthetic resin layer) 1B laminated by a dry laminating method are adhesive 5 The laminated film 1 formed by joining the two in a flat tubular shape with the polyethylene base film 1B positioned inward, and the first polymerized portion 1a on the side along the tubular axis direction. The second overlapped portion 1b on the side that is the bottom of the bag is heat-sealed. Next, after the object W to be packaged is filled into the bag from one opening 2 which is not heat-sealed, the third polymerized portion 1c on the side forming the opening 2 is sealed by heat-sealing. And in such a packaging bag, FIG.
As shown in FIG. 6, between the two base material films 1A and 1B constituting the laminate film 1, the first polymerized portion 1 is formed.
A portion where the adhesive 5 is not applied is formed in a band shape at a position adjacent to a along the a, and the non-adhesive portion a capable of exposing the ventilation path 3 communicating with the outside of the bag is formed by the non-application portion. However, in the base film 1B made of polyethylene on the bag internal space S side corresponding to the non-adhesive portion a, the ventilation passage 3 is formed.
And a plurality of cuts (which are an example of a communication port) 4 for connecting and communicating with the bag inner space S are formed at a predetermined pitch in the longitudinal direction of the air passage 3, and polyethylene facing the bag inner space S is formed. In the base material film 1B made of a material, a part in the vicinity of the peripheral edge of the cut 4 and a part opposed to each other with a part of the bag internal space S sandwiched therebetween are heat-sealed (part indicated by P1 in the figure). I am doing it. That is, when the first polymerized portion 1a of the packaging bag is heat-sealed, the side of the heat-sealed portion 1a facing the bag internal space S is formed into a continuous corrugated shape so as to enter the cut 4 side, Of the polyethylene base film 1B facing between the bag internal spaces S, a film portion in the vicinity of the peripheral edge of the cut 4 and a film portion opposed to each other with a part of the bag internal space S sandwiched therebetween are heat-melted. Wear (P in the figure
1)). The length of each of the cut lines 4 is set to be slightly larger than the width of the ventilation passage 3. Then, a base film 1A made of nylon and a base film 1B made of polyethylene which cannot be heat-sealed to each other.
Since the non-adhesive portion a formed between and can expose the ventilation path 3 communicating with the outside of the bag, when the periphery of the packaging bag is sealed by heat fusion while crossing the non-adhesive portion a. However, the ventilation passage 3 exposed by the non-adhesive portion a is not closed. Therefore, even if the non-adhesive portion a is provided at any position of the packaging bag, the predetermined ventilation passage 3 can be surely exposed, so that the ventilation passage 3 can be located at any position corresponding to the form of the packaging bag. Can be set to. Further, when only the non-adhesive part a exposing the ventilation passage 3 and the cut 4 are formed, when the internal pressure of the packaging bag rises due to external factors such as ambient temperature and external pressure, it is evenly distributed on the inner surface of the bag. Due to the working pressure, the non-adhesive portion a and the peripheral edge of the notch 4 come into close contact with the outer nylon base material film 1A, so that the discharging function does not work at all. Therefore, in the present invention, as described above, the polyethylene base film 1B on the inner side of the laminate film 1 facing the bag internal space S.
Among these, since the film portion in the vicinity of the peripheral edge of the cut 4 and the film portion opposite thereto are heat-sealed (the portion indicated by P1 in the figure), the inner pressure of the packaging bag is the ambient temperature or the outer pressure. When the temperature rises due to external factors such as, the non-heat-sealed phase-opposed film portion (P2 in the figure) located around the heat-sealed phase-opposed film portion (portion indicated by P1 in the figure). The portion (shown) bulges outward, and a large number of cuts 4 formed in the polyethylene base film 1B corresponding to the non-adhesive portions a are greatly opened, and ventilation is communicated with these cuts 4. The fluid in the bag inner space S can be smoothly discharged to the outside through the passage 3. However, in a normal state where the internal pressure of the packaging bag is below a set value (below atmospheric pressure), the many notches 4 and the non-adhesive portions a forming the ventilation passages 3 are in close contact with each other, so that the inside of the bag is in a highly airtight state. Will be maintained.

Next, an example of manufacturing the laminated film 1 by a dry laminating method will be described. FIG.
As shown in FIG. 11, the nylon base film 1A fed from the first roll 10 is guided to the coating portion A, and the nylon 5 is coated with the coating roll 12 and the rubber roll 13 immersed in the adhesive 5 in the tank 11. The adhesive 5 is applied to one side surface of the base material film 1A. At this time, an annular groove 12a having the same width as the width of the ventilation passage 3 is formed on the outer peripheral surface of the coating roll 12 and at a portion corresponding to the non-adhesive portion a. The adhesive 5 is configured not to be transferred to the corresponding portion. Further, the polyethylene base material film 1B fed from the second roll 14 is guided to the cutting portion B, and the rotary cutter 15 makes cuts 4 in a portion corresponding to the non-bonded portion a at a predetermined pitch. Then, the nylon base film 1A sent from the coating section A via the drying furnace 16 and the polyethylene base film 1 sent from the cutting section B.
B and B are led to the laminating part C, and both of these base film 1
After A and 1B are bonded to each other by the heating metal roll 17 and the rubber roll 18, they are cooled by the cooling roll 19 and the manufactured laminated film 1 is wound on the third roll 20. Examples of the adhesive 5 include urethane-based resins, vinyl acetate-based resins, and natural rubbers, which are used after being dissolved in an organic solvent.

In the manufacturing method, since the width of the laminated film 1 is set to a developed width corresponding to one packaging bag, the non-adhesive portion a to which the adhesive 5 is not applied is located in the film width direction. Although it will be formed only at the location, when the width of the laminate film 1 has a development width corresponding to a plurality of packaging bags, the non-adhesive portion a to which the adhesive 5 is not applied is in the film width direction. It will be formed at a plurality of locations. Further, in the first embodiment, the laminate film 1 having a two-layer structure of nylon and polyethylene has been described as an example, but the present invention is not limited to this two-layer structure, and for example, polypropylene. There are a three-layer structure of a vapor-deposited polyester and polyethylene, a three-layer structure of nylon, a vapor-deposited polyester and polyethylene, and the like, and the number and material of the synthetic resin layers may be appropriately selected according to the purpose of use.

[Second Embodiment] In the first embodiment described above, a part of the film portion of the polyethylene base film 1B facing the bag inner space S near the periphery of the cut 4 and When heat-sealing the film portions facing each other with a part of the bag internal space S sandwiched between them,
The overlapped portion 1a was heat-sealed at the same time by heat-sealing it in a continuous corrugation such that the side facing the bag internal space S enters the cut 4 side, but as shown in FIG. The one polymerized portion 1a may be simultaneously heat-sealed with a continuous waveform such that the width of the first polymerized portion 1a is locally narrowed. In the case of this embodiment, even when the packaging bag is sealed using the existing heat sealing machine, it is only necessary to scrape off the width of the pressure-bonded seal portion into a continuous wave shape, which can be advantageously carried out in terms of equipment. There is an effect that can be done.

[Third Embodiment] In the above-described first embodiment, a part of the polyethylene base film 1B facing between the bag inner spaces S and a film portion in the vicinity of the peripheral edge of the cut 4 and In heat-sealing the film portions facing each other across the bag inner space S, the film portions facing each other were simply pressure-welded from the thickness direction and heat-sealed. As shown in FIG. A part of the film portion 1b in the vicinity of the peripheral edge of the cut line 4 is cantilevered in a cantilevered supporting state, and a part of the cantilevered film portion 1b faces a part of the bag internal space S so as to face each other. Alternatively, heat fusion may be performed (portion indicated by P1 in the figure).

[Fourth Embodiment] FIG. 14 shows a double-seal type packaging bag in which the bag internal space S is divided into two divided internal spaces S1 and S2.
Single air passage 3 that leads to the outside of the bag while crossing 1, S2
To form a non-adhesive part a,
The synthetic resin layer 1 on the side of each divided internal space S1, S2 corresponding to
In B, a plurality of V-shaped cuts 4 are formed to connect the ventilation passage 3 and the divided internal spaces S1 and S2 in communication with each other, and the innermost synthetic resin layer facing the divided internal spaces S1 and S2 is formed. Of 1B, the vicinity of the peripheral edge of the cut line 4, in other words, a part located between the specific adjoining of the cut line 4 and a portion facing each other with a part of each of the divided internal spaces S1 and S2 sandwiched therebetween. Spot heat fusion (portion indicated by P1 in the figure)
I am doing it. The bag internal space S is divided into a plurality of divided internal spaces S.
When divided into 1 and S2, it is not always necessary to provide a common single air passage 3 as in the fourth embodiment, and it is dedicated to communicate with each of the divided internal spaces S1 and S2 individually. It is also possible to implement it by providing the ventilation path 3.

[Fifth Embodiment] As shown in FIG. 15, the laminate film 1 comprises four synthetic resin layers 1A to 1D.
And the outermost synthetic resin layer 1A and the adjacent synthetic resin layer 1B are made of synthetic resin materials that cannot be heat-sealed to each other, the outermost synthetic resin layer 1A is located on the outermost side. Between the synthetic resin layer 1A and the synthetic resin layer 1B adjacent thereto, a non-adhesive portion a capable of exposing the ventilation path 3 communicating with the outside of the bag is formed, and the bag internal space S side corresponding to the non-adhesive portion a The synthetic resin layers 1B to 1D may be formed by forming a communication port 4 that connects the ventilation passage 3 and the bag internal space S.

[Other Embodiments] In the first embodiment, the packing bag of the seal-sealing type has been described as an example, but the packing bag of the three-way sealing type as shown in FIG. 16 and as shown in FIG. The technique of the present invention can be applied to a wide variety of packaging bags such as a stand-seal packaging bag and a four-way gusset gassho seal packaging bag as shown in FIG. In the first embodiment, the laminated film 1
Was manufactured by a dry laminating method, but the manufacturing method is not limited to this, and for example, a wet laminating method, an extrusion laminating method, a hot melt laminating method, a co-extrusion laminating method or the like may be used. . In the above-described first embodiment, the communication port 4 is composed of a cut, but it may be composed of a slit-shaped through hole, a circular through hole, or the like. Of the innermost synthetic resin layer 1B facing the bag inner space S, a part of the periphery of the communication port 4 or a portion in the vicinity thereof and a part facing each other with a part of the bag inner space S sandwiched therebetween are heat-melted. When the inner pressure of the packaging bag rises due to external factors such as ambient temperature and external pressure, the peripheral edge of the communication port 4 or the vicinity thereof is located around the heat-sealed portion. This is a position within a range in which the communication port can be opened even by a small amount due to outward bulging deformation of the opposing portions of heat fusion.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a perspective view showing an exhaust state in a portion corresponding to a valley portion of a continuous wave-shaped heat-sealing portion in a ventilation path of a packaging bag.

FIG. 2 is a perspective view showing an exhaust state in a portion corresponding to a mountain portion of a continuous wave-shaped heat-sealing portion in a ventilation path of a packaging bag.

FIG. 3 is a sectional view taken along line III-III of FIG.

FIG. 4 is a perspective view showing a normal airtight state in a portion corresponding to a valley portion of a continuous wave-shaped heat-sealing portion in a ventilation path of a packaging bag.

FIG. 5 is a perspective view when a continuous wave heat-sealing portion of a packaging bag is cut out in a stepwise manner.

FIG. 6 is an exploded perspective view of a portion where a ventilation path is formed in a laminated film.

FIG. 7 is a perspective view of a packaging bag before being filled with an object to be packaged.

FIG. 8 is a perspective view showing a packaging bag after packaging.

FIG. 9 is a schematic view showing a manufacturing method by a dry lamination method.

FIG. 10 is a perspective view showing an adhesive applying step in the coating section.

FIG. 11 is a perspective view showing a laminating process in a laminating unit.

FIG. 12 is a perspective view when a continuous wave-shaped heat-sealing portion of the packaging bag according to the second embodiment is cut out in a stepwise manner.

FIG. 13 is a perspective view showing an exhaust state of a ventilation path of a packaging bag according to a third embodiment.

FIG. 14 is a partially cutaway perspective view of a packaging bag according to a fourth embodiment.

FIG. 15 is an enlarged sectional view of the packaging bag showing the fourth embodiment.

FIG. 16 is a perspective view showing a three-sided seal type packaging bag.

FIG. 17 is a perspective view showing a stand-seal type packaging bag.

FIG. 18 is a perspective view showing a packaging bag of a four-way gusset gassho seal type.

FIG. 19 is a sectional view of an essential part showing a conventional packaging bag.

[Explanation of symbols]

 1 Laminated Film 1A Synthetic Resin Layer (Base Film) 1B Synthetic Resin Layer (Base Film) 3 Ventilation Path 4 Communication Port 5 Adhesive a Non-Adhesive Part S Bag Internal Space

Claims (3)

[Claims] A plurality of joined synthetic resin layers (1A, 1A).
B), at least a pair of adjacent synthetic resin layers (1)
A, 1B) is a packaging bag formed by heat-sealing a laminate film (1) made of a synthetic resin material that cannot be heat-sealed to each other in a bag shape, and the synthetic resin layer of the laminate film (1). (1A, 1
In B), a non-adhesive portion (a) capable of exposing a ventilation passage (3) communicating with the outside of the bag is formed in a part between the synthetic resin layers (1A, 1B) which cannot be heat-fused. The synthetic resin layer (1B) on the bag internal space (S) side corresponding to the bonded portion (a) is formed with a communication port (4) for connecting the ventilation passage (3) and the bag internal space (S). In addition, in the innermost synthetic resin layer (1B) facing the bag inner space (S), a part of the periphery of the communication port (4) or the vicinity thereof and a part of the bag inner space (S). A packaging bag in which parts facing each other with the sheet sandwiched therebetween are heat-sealed. 2. The communication port (4) has a non-adhesive portion (a).
The packaging bag according to claim 1, wherein the packaging bag has cuts formed in the synthetic resin layer (1B) on the side of the internal space (S) of the bag. 3. A base film (1A, 1B) made of synthetic resin, wherein the non-adhesive part (a) is bonded to a plurality of layers, and two base films (1A, 1A, 1A, 1B) that cannot be heat-sealed to each other. 1
A laminated film for a packaging bag, which is composed of a non-coated portion of the adhesive (5) for joining B).