JPH05330562A - Gusseted bag - Google Patents

Abstract

(57) [Summary] [Structure] A bottom portion 13 for connecting the lower ends of the front body portion 11 and the rear body portion 12 of the gusset bag formed of a laminated film composed of a heat-bonding inner surface layer and a non-heat-bonding outer surface layer is formed. The folding surface portions 13a and 13b are formed, and two or more substantially semicircular cutout portions 100 are formed on both sides of the folding portion.
110 is formed, and the front and rear body portions and the left and right side portions of the bottom folded portion are integrally heat-sealed. [Effect] It is possible to obtain a gusset bag that can be easily manufactured by either the one-piece manufacturing method or the two-piece manufacturing method and has a sufficient adhesive capacity while having a strong adhesive strength.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gusset bag, and more particularly to a gusset bag in which a heat-sealed portion of a bag body made of a laminated film in which an outer layer is a non-heat adhesive layer and an inner layer is a heat adhesive layer is improved. Regarding

[0002]

2. Description of the Related Art Conventionally, a laminated film comprising a heat-adhesive inner surface layer and a non-heat-adhesive outer surface layer is used, and the upper side is opened and the left and right side portions and, if necessary, the lower bottom portion are heat-sealed. So-called gusseted bags that are glued are known. A structure of a conventional gusset bag and a method of manufacturing the same will be described with reference to FIGS.

FIG. 4 shows a conventionally known gusset bag 10, in which a front main body portion 11 located at the front in the figure,
It is basically composed of a rear body portion 12 located behind it and a bottom portion 13 connecting the lower ends of the front and rear body portions. In the production, a laminated film 1 having a non-adhesive outer layer such as paper, aluminum foil, polyester, nylon and the like and a heat-adhesive inner surface layer such as a heat-adhesive synthetic resin is used. At the time of production, it is usually produced continuously from a roll of the laminated film 1.

FIG. 5 schematically shows a state in which the gusset bag 10 shown in FIG. 4 is in the process of being manufactured. The laminated film 1 having a predetermined width (that is, the dimension between the both sides 4, 4'of the bag).
Is folded back from the first folded-back portion 2 at the center in the widthwise direction thereof, and is further folded back in the opposite direction at the second folded-back portions 3 and 3'position in consideration of the size of the bottom required for the bag 10 and the like. ing. In this figure, the surface portions from the two upper edge portions to the second folded portions 3, 3'constitute front and rear body portions 11, 12, and the lower ends of the front and rear body portions 11, 12 or the second folded portions The surface portion, which is located between the portions 3 and 3 ′ and is folded toward the upper edge direction, which is open, constitutes a folding portion of the bottom portion 13 of the gusset bag. For ease of explanation, the surface portion of the bottom portion 13 between the first folded portion 2 and the second folded portion 3 is referred to as the first folded surface portion 13a, the first folded portion 2 and the first folded portion 2. The surface portion between the two folded-back portions 3 ′ will be described below as the second folded-in surface portion 13b.

As best shown in FIG. 5, the first and second
In the left and right side portions of the folding surface portions 13a, 13b, one notch 20, 20 'having a substantially semi-arcuate shape is provided, respectively, for the purpose to be described later, the first and second folding surface portions 13a, 13b.
It is formed at a position that is substantially the same when b is overlapped. While pressing the laminated film folded body in the state of FIG. 5 in a close contact state, both side portions and, if necessary, the lower side portion are heated. As described above, since the inner surface of the laminated film 1 is a heat-adhesive layer, the portions that are heat-pressed and the inner surfaces of the film face each other are heat-sealed. Therefore, as shown in FIG. 4, in the gusset bag of this example, a heat seal is formed between the side inner surface portions of the front body portion 11 and the rear body portion 12 in the left and right side portions. 30, 30 '
The inner side portion of the front body portion 11 and the first folding surface portion 1
3a and the side inner surface portion of the rear body portion 12 and the side inner surface portion of the second folding surface portion 13b 31, 31 'are heat-sealed, and further, the front body portion 11
Between the bottom inner surface portion of the first folding surface portion 13a and the bottom inner surface portion of the first folding surface portion 13a, and between the bottom portion inner surface portion of the rear body portion 12 and the bottom portion inner surface portion of the second folding surface portion 13b 32 '. Heat sealed.

As can be seen from FIG. 5, the first and second folding surface portions 13 forming the bottom portion 13 of the gusset bag 10.
In a state in which the respective surface portions are brought into close contact with each other, a and 13b have their outer surfaces, that is, the non-heat-adhesive outer surface layers, face each other. Therefore, when pressure-bonding and heating are performed without forming the notches 20 and 20 ', the folded-back portion of the bottom portion 13 of the bag 10 is not heat-sealed, and the folded-back portion expands.
This means that the surface that forms the bottom of the bag cannot maintain a flat state, and when the required items are stored in the bag, the posture becomes extremely unstable and the display is placed on the display stand. It is not preferable in such cases.

The notches 20 and 20 'are formed therefor, and as will be easily understood from FIG. 5, the front body portion 11 passes through the notches 20 and 20' when it is pressure-bonded and heated. It becomes possible to directly face the inner surfaces of the side portion of the rear body portion 12 and the inner surface of the side portion of the rear body portion 12, and the lower side portion of the bag body is heat-sealed 35, 35 'in that portion. As a result, when the contents are accommodated in the gusset bag 10, the two second folded-back portions 3 and 3 ′ described above can be expanded in an arc shape with their both ends fixed to each other. The bottom surface of the body always forms a substantially horizontal surface regardless of the content.

Therefore, this type of gusset bag is extremely effective as a container having high self-sustainability and is widely used in the food industry and the like.

[0009]

However, the gusset bag of the above-mentioned form still has problems to be solved.
That is, in order to store the contents in the bag and maintain the posture thereof in a substantially cylindrical shape or an elliptic cylindrical shape, the notch 2
It is necessary that the heat-sealing portions 35, 35 'in the lower side portions of the bag bottom portion 13 formed by 0, 20' have a certain adhesive strength, and the adhesive strength of the heat-sealing portion is usually the adhesive area. The notches 20 and 20 'require a certain area because they are proportional to

FIG. 6a schematically shows the state of the surface of the roll-shaped laminated film 1 used as a raw material for the gusset bag of this type. The openings 21 and 21 'are formed by an appropriate punching means (not shown) in the area between the formed second folded portions 3 and 3'for the center line in the width direction of the original (the first folded portion 2). To be done. The openings 20 and 20 'are finally cut at the positions of the lines 4 and 4'which define the width of the bag body and divided into two, whereby the notches 20 and 20' are formed.
Will form a part.

The openings are typically formed into a circle from the convenience of machining. Then, after being folded into the shape shown in FIG. 5 by an appropriate folding machine not shown,
As described above, a predetermined portion is heated and heat-sealed by an appropriate thermocompression bonding means (not shown). After that, by an appropriate cutting means not shown in FIG.
4'is cut to form the gusset bag shown in FIG.

FIG. 6b shows the heat-sealed portion developed on a flat laminated film, and the shaded portion is the heat-sealed portion. As will be readily understood, the internal volume of the gusset bag depends on the amount of heat-sealed area. Therefore, it is desirable that the area to be heat-sealed is small, but on the other hand, the bag itself must have sufficient adhesive strength so as not to be broken, and the heat-sealed area is set to an optimum value depending on the material used or the conditions such as the bag size. ..

On the other hand, as described above, it is necessary that the heat seal portions 35, 35 'in the lower side portions of the bag bottom portion 13 have a certain adhesive strength, and therefore the notches 20, 2 are formed.
0'requires a certain area. Then, in a normal gusset bag, the opening is formed in a circular shape, and if the seal width required for heat sealing of both side portions is h and the radius of the cuts 20 and 20 ′ is d, h < It is usually d.

When the bag body under the condition of h <d is heat-sealed only on the left and right side portions by the width h, the portion shown by x in FIG. It will be easily understood that the portion located outside the seal width h is not hermetically sealed and that portion forms a communication portion with the outside. Therefore, in a normal case, as shown in FIGS. 4 and 6, the openings 21, 21 ′ (the notch 20,
20 ') is to be heat-sealed in a wider area near the bottom of the bag to completely seal the vicinity of the periphery of the bag, or heat-sealed so that the sealing width h on both sides is h> d. Yes, and in each case, the available internal volume is limited.

As one means for solving the above-mentioned inconvenience, it has been proposed to make the opening into an oval or rectangular shape instead of a circular shape. An example thereof will be described with reference to FIG. The plane shape and dimensions of the laminated film shown in FIG. 7 are almost the same as those described with reference to FIGS. 4 to 6, but only the shape of the opening 50 is different. As is clear from the figure, the short side length of the opening 50 is 2 w.
Is set to be 2w <h, and the length W of the long side is selected so that the necessary heat sealing area can be obtained in that state. In this case, set the heat seal width on both sides of the bag to the minimum required width h.
Since the gusset bag can be manufactured by heat-sealing in such a state, the internal volume can be fully utilized, and the above-mentioned inconvenience is once solved.

However, even in this case, there is still a problem to be solved. One is that when punching an opening in this kind of laminated film, it is common to punch it in a circle and the work is relatively easy, but as mentioned above, special equipment is prepared for punching into an oval or rectangle. Is required and workability is not easy. Further, in the above description, the gusset bag has been described as being continuously manufactured from one laminated film, but as another manufacturing method, the main body portion and the bottom portion of the bag body are separated from each other. So-called 2 to prepare from the roll of laminated film roll
There is a piece manufacturing method. The two-piece manufacturing method will be briefly described with reference to FIG.

The laminated film 1a constituting the main body portion and the laminated film 130 constituting the bottom portion are supplied from different roll stocks. The above-described opening 50 is formed in the laminated film 130 by an appropriate punching means (not shown) (FIG. 8a). Both films are pulled out further and folded by the folding guides respectively (Fig. 8).
b) Then, after being integrated together (FIG. 8c), it is heat-sealed by crimp heating as described with reference to FIGS. 4 to 6 and cut to form individual gusset bags.

In this case, the width of the laminated film 130 constituting the bottom portion is naturally narrow. When punching the above-mentioned required opening there, when the shape of the opening is circular, no particular problem occurs because the ratio of the diameter of the opening to the lateral width of the film is a relatively low value. As described above, when the opening has an oval or rectangular shape, the ratio of the major axis of the oval or rectangular to the lateral width of the film becomes a high value, which causes a great inconvenience. That is, in the process of drawing the film from the original roll to the process of pressure-bonding heating, the film is likely to be broken at the opening portion, which causes a time loss for restoration and a material loss due to the breaking. Therefore, the gusset bag having the shape described with reference to FIG. 7 and the manufacturing method thereof were not suitable for the two-piece manufacturing method.

The object of the present invention is to eliminate the above-mentioned disadvantages of the prior art and to provide a gusset which can be easily manufactured by any manufacturing method and has a sufficient internal capacity but has a strong adhesive strength. To get a bag.

[0020]

In order to solve the above-mentioned problems and to achieve the object, the present invention is a gusset bag formed by a laminated film comprising a heat-adhesive inner surface layer and a non-heat-adhesive outer surface layer. And has a front body portion, a rear body portion, and a bottom portion connecting the lower ends of the front and rear body portions,
The bottom portion has a folded portion that is folded toward the open upper edge direction of the gusset bag, and two or more substantially semicircular cutout portions are formed on both side portions of the folded portion. Disclosed is a gusset bag, characterized in that at least the front and rear body portions and the left and right side portions of the bottom folding portion are integrally heat-sealed.

In the present invention, the front and rear body portions and the bottom portion may be formed by a continuous laminated film or may be formed by separate laminated films.

[0022]

The present invention will be described in more detail based on the following examples. FIG. 1 is a plan view of a laminated film used in manufacturing a gusset bag according to the present invention, and FIG. 2 is a perspective view in the manufacturing process thereof. Note that FIG. 1 corresponds to FIGS. 6 and 7 used in the description of the conventional example,
2 corresponds to FIG. 5, and there is substantially no difference except for the shape of the opening (notch) described later.
Therefore, the same portions are denoted by the same reference numerals and detailed description thereof will not be given. Further, regarding the structure and material of the laminated film, those of the conventional example can be used as they are.

In the gusset bag of the present invention, the opening (notch) is formed by at least two or more semi-circular notches. In the embodiment shown in FIGS. 1 and 2, the opening is 2
It is formed by individual semicircles 101, 111 (101 ', 111'). That is, as shown in FIG. 2, two substantially semi-circular cutouts 10 are formed on the left and right sides of the first and second folding surface portions 13a and 13b, respectively.
0, 110 (100 ', 110') are formed at positions that are substantially the same when the first and second folding surface portions 13a, 13b are overlapped. And two semi-circular notches 100, 110 (100 ', 110')
The diameter of the arc is set so that the heat sealing strength of the folded portion required for the bag can be obtained by the total area of the above.

Therefore, the diameter of the cutout portion according to the present invention is larger than the diameter d in the case where the cutout portion is formed by one semi-circular arc (that is, in the case of the type described in FIGS. 4 to 6). D becomes a small dimension, that is, D <d, and the value can be made smaller than the heat-sealing width h of the left and right side portions of the gusset bag, that is, D <h. As a result, it is possible to avoid forming a heat seal area larger than a required value as in the conventional example in FIGS. 4 to 5,
It is possible to make maximum use of the internal volume.

Further, the arcuate punching is easy, and by dividing the opening portion into a plurality of portions, a long-sized incision portion is not formed unlike the case of an oval or rectangular opening. As a result, even when the gusset bag is manufactured by the two-piece manufacturing method as described in FIG. 8, it is possible to sufficiently prevent the laminated film forming the bottom portion from being broken during the manufacturing process.
FIG. 3 shows an intermediate diagram in the case of manufacturing the gusset bag of the present invention by the two-piece manufacturing method. In this case, it is easily understood that heat sealing of the lower side part is required in addition to the both side parts. See.

The above description is only one embodiment of the present invention, and there are many other modifications. Regarding the shape and size of the opening, the point is that the area of the heat-seal part to obtain the required strength required to integrally bond the folded part of the bottom part of the gusset bag to the front and rear body parts is a single cut. It should be obtained not from the cutout but from the cutout divided into a plurality of pieces. The number of cutouts is not limited to two, and the size of the gusset bag, machinability, etc. should be taken into consideration. It may be set to an appropriate number. Further, it is a preferable mode that the shape of the notch is a semi-circular arc because it can be coped with by an ordinary punching machine, but the shape is not limited to this, and the shape is formed from a part of the circular arc, and an appropriate flat arc. The number can be appropriately selected in consideration of the shape and the workability.

[0027]

Since the gusset bag according to the present invention has the above-mentioned structure, it can be easily manufactured by any manufacturing method and has a sufficient internal capacity, but has a strong adhesive strength. Can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic development view of a laminated film for producing a gusset bag according to the present invention.

FIG. 2 is a perspective view showing a process of manufacturing a gusset bag according to the present invention.

FIG. 3 is a perspective view showing a manufacturing process of another embodiment of the gusset bag according to the present invention.

FIG. 4 is a perspective view showing a conventional gusset bag.

FIG. 5 is a perspective view showing a manufacturing process of a conventional gusset bag.

FIG. 6 is a developed schematic diagram of a laminated film for producing a conventional gusset bag.

FIG. 7 is a development schematic diagram of a laminated film for manufacturing another conventional gusset bag.

FIG. 8 is a schematic diagram illustrating a two-piece manufacturing method.

[Explanation of symbols]

11 ... front body portion, 12 ... rear body portion, 13 (13a,
13b) ... bottom part (folded part), 100, 110 ...
Cutout

Claims (3)

[Claims] 1. A gusset bag formed of a laminated film comprising a heat-adhesive inner surface layer and a non-heat-adhesive outer surface layer, the bottom body connecting a front body portion and a rear body portion and lower ends of the front and rear body portions. And a bottom portion having a folded portion folded toward the upper edge direction of the gusset bag, and at least two or more of the folded portions are provided on both side portions of the folded portion. A semi-circular cutout is formed,
A gusset bag, characterized in that at least the front and rear body portions and the left and right side portions of the bottom folding portion are integrally heat-sealed. 2. The gusset bag according to claim 1, wherein the front and rear body portions and the bottom portion are formed of a continuous laminated film. 3. The front and rear body portions and the bottom portion are formed by separate laminated films,
The gusset bag according to claim 1.