JP2010208701A - Method of manufacturing air-permeable bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air-permeable bag which enables air-enclosed in the bag during filling to be discharged satisfactorily, is low in cost, and is usable for packing rice or the like. <P>SOLUTION: The bag has intermittent heat adhesive parts each composed of a heat adhesive part and a non-heat adhesive part formed on two opposing sides by overlapping two square laminate films each having a base material layer and the heat adhesive resin layer with the heat adhesive resin layer surfaces facing each other. The intermittent heat adhesive parts are mounted with unevenness formed preliminarily in the area of the laminate film where the intermittent heat adhesive parts are going to be formed. By the unevenness is formed on the non-adhesive part of the intermittent heat adhesive part of at least one of the laminate films. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bag having air permeability suitable for a rice bag or the like that can easily deaerate air enclosed inside when filling the contents.

  Conventionally, as a breathable bag used as a rice bag or the like, two heat-adhesive laminated films having a quadrangular shape are overlapped, and intermittent heat bonding consisting of a heat-bonding portion and a non-heat-bonding portion on two opposing sides. There is known a bag having a configuration in which a part is formed and air inside the bag is discharged from the non-thermally bonded part of the formed intermittent heat bonded part to be deaerated. However, in the case of the bag having this structure, the laminated films are in close contact with each other at the non-thermal bonding portion, and there is a disadvantage that it is difficult to deaerate the internal air because it is difficult to form a gap between the two laminated films. In addition, if the non-thermally bonded portion is enlarged, it becomes easy to deaerate, but there is a problem that contents such as rice stored inside leak out or insects enter the bag.

  As a breathable bag that improves the above-mentioned drawbacks, for example, a location where two films overlapping each other at the periphery of the storage bag are bonded together by heat sealing as described in Registered Utility Model Publication No. 3053828 Non-adhesive parts are formed at appropriate intervals in the length direction of the joints at appropriate positions, and the non-adhesive part is made of a non-woven tape folded in two between two films, and the folded part is inside the storage bag. Each piece of the folded non-woven tape is fused to each layer constituting the inner surface side of the two films, but each piece is interposed so as not to be fused, and the non-adhesive part is an air vent part. A storage bag having the structure described above is known (for example, see Patent Document 1). However, in the storage bag of the above configuration, since the non-adhesive tape is inserted in the non-adhesive portion formed at appropriate intervals in the length direction of the joint portion, it is easy to discharge the air in the bag, Since the configuration is such that a non-woven tape is inserted into the heat seal portion, there are disadvantages that the manufacturing process becomes complicated and the cost increases because the non-woven tape is used.

  Further, in order to facilitate the discharge of air in the bag, the bag has an intermittent thermal bonding portion formed of a thermal bonding portion and a non-thermal bonding portion along two opposite sides of the quadrangular shape. The thing of the structure shape | molded so that the laminated | multilayer film in the area | region used as the non-heat bonding part of a heat bonding part may bulge outward is known. However, in the bag of this configuration, it is necessary to accurately align the region that becomes the non-thermal bonding portion of the intermittent thermal bonding portion with a relatively narrow interval, and to form the bulging portion by a hot press or the like, The manufacturing process is extremely complicated.

Registered Utility Model Publication No. 3053828

  An object of the present invention is to provide a breathable bag for packaging low-cost rice or the like, which has good deaeration of air enclosed in the bag.

  Intermittent heat-bonding part consisting of a heat-bonding part and a non-heat-bonding part on two opposite sides of a two-layered laminated film provided with a base material layer and a heat-adhesive resin layer, with the heat-adhesive resin layer surface overlapped In the non-thermal bonding portion of the intermittent heat bonding portion, the non-thermal bonding portion of the intermittent heat bonding portion is formed on the laminated film. A gap is formed between the two laminated films due to the unevenness, and air is discharged from the gap, so that a breathable bag having excellent deaeration can be obtained.

  In the breathable bag described above, an intermittent heat bonding portion is formed in a state where unevenness is formed in advance in a region where the intermittent heat bonding portion of the laminated film is formed, and the unevenness is formed on the laminated film in the non-thermal bonding portion; By doing so, it is possible to reliably form irregularities on the laminated film in the non-thermally bonded part of the intermittent heat bonding part, so that the air inside can be easily passed through the gap formed between the two laminated films by the irregularities. Can be degassed.

  In the above-described air-permeable bag, the concave and convex portions are point-like protrusions protruding to the inner surface side of the laminated film, so that the external parts are formed by the dot-like protrusions between the two laminated films in the non-thermally bonded portion of the intermittent heat bonded portion. Since a gap communicating with the air bag is formed, a breathable bag with excellent deaeration can be obtained.

  Intermittent heat-bonding part consisting of a heat-bonding part and a non-heat-bonding part on two opposite sides of a two-layered laminated film provided with a base material layer and a heat-adhesive resin layer, with the heat-adhesive resin layer surface overlapped In the bag in which the intermittent heat bonding portion is formed, the intermittent heat bonding portion is formed in a state in which an unevenness having a groove communicating with at least one laminated film in the region where the intermittent heat bonding portion is formed is formed. A groove communicating with the outside of the bag is formed by the unevenness formed in the laminated film between the two laminated films in the non-thermally bonded part of the heat-bonding part, so that the internal air is easily discharged through the groove. Therefore, excellent deaeration can be obtained.

  In the breathable bag described above, the concavo-convex shape is a point-like protrusion protruding to the heat-adhesive resin layer side or a line-like shape intersecting with the longitudinal direction of the intermittent heat-bonding portion, thereby forming a point-like protrusion or a line-like shape. Since the gap is formed by a groove that communicates with the outside of the bag due to the unevenness, the air inside the bag can be discharged and deaerated through the gap.

The top view which shows embodiment of this invention. II expanded sectional view in FIG. The figure which shows the state which forms the intermittent heat-bonding part of embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view taken along the line II in FIG. 1, and FIG. 3 is a diagram showing a state of forming an intermittent thermal bonding portion of the embodiment of the present invention. 1 is a breathable bag, 2 is an intermittent heat bonding part, 2a is a heat bonding part, 2b is a non-thermal bonding part, 3 is an edge thermal bonding part, 4 is uneven, 5 is a hot plate, 5a is a heating part, 5b is A non-heating part, 6 is a stand, 11 and 12 are each a laminated film.

  Embodiments of the breathable bag of the present invention are as shown in FIGS. As shown in FIG. 1, the planar shape is such that two laminated films 11 and 12 each having a quadrangular shape composed of a base material layer and a heat-adhesive resin layer are overlapped on the surface of the heat-adhesive resin layer, and the left and right sides facing each other. The bag is a quadrangular bag in which an intermittent thermal bonding portion 2 including a thermal bonding portion 2a and a non-thermal bonding portion 2b is formed on two sides and an edge thermal bonding portion 3 is formed on the lower end. The thermal bonding part 2a constituting the intermittent thermal bonding part 2 of the embodiment has a shape in which the inner corners are cut obliquely, and the non-thermal bonding part 2b has a wide inner shape.

  The cross-sectional shape in the non-thermal bonding part 2b of the intermittent thermal bonding part 2 of the embodiment is as shown in FIG. 2, and the two laminated films 11 constituting the bag in the non-thermal bonding part 2b of the intermittent thermal bonding part 2 In the structure in which the unevenness 4 by embossing is formed in one laminated film 11 of the laminated film 12, and a gap communicating with the outside is formed between the laminated film 11 and the laminated film 12 by the unevenness 4 formed in the laminated film 11. is there. In the embodiment, when the contents are filled, the air remaining inside the bag can be discharged through the gap formed by the irregularities 4 and communicating with the outside. Moreover, since the inner corner | angular part is cut diagonally and the inner side of the non-thermal-bonding part 2b is wide, the heat bonding part 2a which comprises the intermittent heat bonding part 2 is easy to discharge | emit internal air, and deaerates It has become an excellent one.

  In embodiment, in order to form the unevenness | corrugation 4 by embossing in the laminated | multilayer film 11 in the non-thermal-bonding part 2b of the intermittent heat bonding part 2, as shown in FIG. 3, the area | region which forms the intermittent heat bonding part 2 of the laminated film 11 The unevenness 4 is formed in advance over the entire length of the film, and the laminated film 11 and the laminated film 12 on which the unevenness 4 is formed are overlapped, and the heat plate 5 and the base plate 6 having the heating part 5a and the non-heating part 5b are thermally bonded. By doing so, the heating part 5a of the hot plate 5 forms the thermal bonding part 2a of the intermittent thermal bonding part 2, and the non-heating part 5b of the hot plate 5 forms the non-thermal bonding part 2b of the intermittent thermal bonding part 2. Intermittent thermal bonding part 2 consisting of thermal bonding part 2a and non-thermal bonding part 2b is formed. By this method, the unevenness 4 can be formed in the laminated film 11 over the entire length of the non-thermal bonding part 2b of the intermittent thermal bonding part 2. Further, the portion of the laminated film 11 on which the unevenness 4 is formed is thermally bonded by the heating part 5a of the hot plate 5 and the two laminated films 11 and 12 are completely thermally bonded to each other so that the intermittent thermal bonding part 2 is thermally bonded. Part 2a is formed.

  In the above, the method of forming the intermittent thermal bonding portion 2 by forming the irregularities 4 in advance over the entire length of the region of the laminated film 11 where the intermittent thermal bonding portions 2 are formed is described. You may form partially so as to correspond to the non-heating part 5b of the board 5. FIG. In that case, it is necessary to accurately adjust the position of the unevenness 4 formed on the laminated film 11 so as to correspond to the non-heated portion 5b of the hot plate 5, so that the process of forming the intermittent heat bonding portion 2 is complicated. become.

  In order to form irregularities on the laminated film, the irregularities can be formed by embossing using a male mold and a female mold. Embossing of the laminated film can be performed at normal temperature or in a heated state, but it is preferable to emboss at normal temperature. In order to form unevenness over the entire length of the region where the intermittent heat bonding portion of the laminated film is formed, a method of embossing the laminated film using a roll-shaped male mold and female mold is performed. The formation of irregularities on the laminated film is achieved by using a roll-shaped male mold and female mold in a process of slitting a laminated film produced by laminating a base material layer and a heat-adhesive resin layer. In the bag making process of forming a breathable bag using a laminated film, an intermittent heat bonding part may be formed by a hot plate 5 having a heating part 5a and a non-heating part 5b. At the stage before forming 2, the laminated film may be embossed to form irregularities.

  In the embodiment, the unevenness 4 is formed by embossing only on one laminated film 11, but the unevenness 4 can be similarly formed by embossing on the other laminated film 12. In the case where the laminated film 11 and the laminated film 12 are formed with irregularities, a large gap communicating with the outside can be formed by the irregularities formed in the laminated film 11 and the laminated film 12, so that the bag becomes more excellent in deaeration. However, since it is necessary to emboss two laminated films, the process becomes complicated. As in the embodiment, sufficient deaeration can be obtained only by forming irregularities on one laminated film.

  The shape of the unevenness 4 formed by embossing on the laminated film is not particularly limited as long as a gap is formed between the two laminated films so as to communicate with the outside of the bag. Although it can be in the shape of a diagonal line, a grid, or the like with respect to the longitudinal direction, it is most preferable to use point-like projections in terms of deaeration and workability of embossing. In the case of dot-like projections, the diameter is preferably 0.5 to 1.0 mm, the height is 40 to 100 μm, and the interval is about 0.5 to 2.0 mm.

  As the base material layer constituting the laminated film 1, a biaxially stretched film such as biaxially stretched polyethylene terephthalate, biaxially stretched nylon, or biaxially stretched polypropylene having excellent strength can be used. For the heat-adhesive resin layer, low density polyethylene, medium density polyethylene, linear low density polyethylene, ethylene-α olefin copolymer polymerized using a single site catalyst, ethylene-vinyl acetate copolymer, etc. are used. it can. Since the breathable bag of the present invention is used for packaging rice and the like, it is necessary to be a bag excellent in strength, and linear low-density polyethylene is used as the resin constituting the heat-adhesive resin layer. Most preferably. As the structure of the laminated film, for example, biaxially stretched nylon 15 μm / extruded linear low density polyethylene 60-80 μm, biaxially stretched polyethylene terephthalate 12 μm / extruded linear low density polyethylene 60-80 μm, biaxially stretched nylon 15 μm / dry lamination. / Linear low density polyethylene film 60-80 μm and the like.

DESCRIPTION OF SYMBOLS 1 Breathable bag 2 Intermittent heat bonding part 2a Thermal bonding part 2b Non-thermal bonding part 3 Edge thermal bonding part 4 Concavity and convexity 5 Hot plate 5a Heating part 5b Non-heating part 6 Base 11,12 Laminated film

Claims (3)

Intermittent thermal bonding consisting of a heat-bonded part and a non-heat-bonded part on two opposite sides of a two-layered laminated film provided with a base material layer and a heat-adhesive resin layer, with the heat-adhesive resin layer surfaces superimposed. In the bag in which the part was formed, the breathable bag is characterized in that at least one of the laminated films is provided with irregularities in the non-thermally bonded part of the intermittent heat bonded part. The intermittent heat-bonded portion is formed in a state where irregularities are formed in advance in a region where the intermittent heat-bonded portion of the laminated film is formed, and the laminated film in the non-thermally bonded portion is configured to have unevenness. The breathable bag according to claim 1. The breathable bag according to claim 1 or 2, wherein the unevenness is a point-like protrusion protruding toward the inner surface side of the laminated film.

Images