JP4313660B2 - Packaging bag manufacturing method - Google Patents

Description

  The present invention relates to a packaging bag that is flexible but excellent in self-supporting property and a method for manufacturing the same.

Conventionally, a packaging bag (also referred to as a self-supporting bag) that is flexible but excellent in self-supporting property has been manufactured using a plastic film or a laminate film formed by laminating a plastic film with aluminum foil, paper, or the like. For example, Patent Document 1 describes a method of manufacturing a self-supporting bag from a long plastic film by disposing a body film (body structure part) on both sides of a bottom film (bottom structure part).
This type of packaging bag is excellent in autonomy when the contents are filled and unopened. However, if the bag is opened and a part of the contents is taken out and the remaining amount is low, the independence becomes worse, the bag may be bent in the middle and the bag mouth may face down, and the contents may leak or spill . In particular, when a spout made of plastic or the like is provided in the upper part of the bag, the position of the center of gravity becomes higher, the stability is further deteriorated, and the bag may fall down. Further, if the bag is bent when the content is tilted to pour out the content, the content cannot be poured into a desired position and may spill.

As a method for improving the self-supporting property of the packaging bag, for example, Patent Document 2 describes a container provided with reinforcing means on a side extending in the vertical direction when the bag is self-supporting. As the reinforcing means, as described in paragraphs 0035 to 0037 of the specification, (a) a method in which a core material is sandwiched between two sheets when the sheets are welded to each other, and (b) a core material (C) a method of fixing a U-shaped reinforcing means from the outside of the welded part after welding two sheets, and (d) a saddle-like welded part when the sheets are welded together (E) a method of folding back and adhering or welding the welded portion, (f) welding two reinforcing sheets, and then reinforcing means having a U-shaped cross section and having a return to prevent the inner surface from coming off. The method of inserting from the outside of the part and (g) the method of sandwiching the double-folded reinforcing means from the outside of the welded part are illustrated.
Patent Document 3 describes that both sides and upper edges of a bag are joined by thermoplastic resin injection molding to form a joint having high strength, thereby improving the self-supporting property of the bag. Has been.
Japanese Patent No. 2572499 JP 2000-335596 A JP 2003-191964 A

However, when a self-supporting bag is continuously manufactured from a long plastic film (for example, the method described in Patent Document 1), the side portion of the bag is along the lateral direction of the plastic film (direction perpendicular to the longitudinal direction). It is formed. For this reason, when the bag is reinforced by the method described in Patent Document 2, it is necessary to position and weld the core material between the two sheets in the method described in (a). There is a possibility that the position of the core material or the sheet may be shifted. Further, in the method described in (b), the core material protrudes outside the sheet and not only the appearance is bad, but also there is a risk of dropping from the bag. In the methods described in (c) to (g), it is necessary to provide reinforcing means after the plastic film is cut in the transverse direction to form individual bags, and it is difficult to automate the formation of the reinforcing means, which is complicated. Work is required.
Moreover, in the method of patent document 3, since it is injection molding, a self-supporting bag cannot be manufactured continuously from a long plastic film, and it is inferior to mass-productivity.

  The present invention has been made in view of the above circumstances, and a method for manufacturing a packaging bag having a configuration in which a reinforcing means is arranged on a side portion of a flexible bag and excellent in self-supporting property, and continuous production is possible and mass production is easy. It is an issue to provide.

In order to solve the above-mentioned problems, the present invention sandwiches a bottom film formed with a fold portion along the longitudinal direction between two body films, and forms two body films and the bottom film of these films. A packaging bag for forming individual bag bodies by forming a portion to be a side portion of the packaging bag by heat welding along a direction orthogonal to the longitudinal direction and cutting a portion to be a side portion of the packaging bag A manufacturing method of
A step of joining a reinforcing member to at least one barrel film at a location that becomes a side portion of the packaging bag, and a trunk member that is joined to the trunk film and a trunk film in which the reinforcement member is not joined, and / or There is provided a method for manufacturing a packaging bag, comprising the step of thermally welding the bottom film in this order.
In this method for manufacturing a packaging bag, when the portion to be the side portion of the packaging bag is cut, the reinforcing member can be cut into two along the direction perpendicular to the longitudinal direction of the body film.
In this invention, it is preferable to further have the process of heat-welding two trunk | drum films in the peripheral part of a reinforcement member.
As the reinforcing member, it is preferable to use one that is integrated with the spout of the packaging bag.

  According to the present invention, since the reinforcing member is joined to the trunk film before the trunk film and the bottom film are overlapped with each other, the reinforcing member can be reliably positioned and the mass productivity is excellent. Reinforcing members improve the shape retention and self-supporting properties of the packaging bag, making it difficult for the packaging bag to bend in the middle of the bag, so even if the remaining amount is small, tilt the bag and pour out the contents, A bag can be easily set up, and leakage and spillage of contents can be suppressed.

The present invention will be described below with reference to the drawings based on the best mode.
1-5 is drawing for demonstrating the 1st example of a manufacturing method of the packaging bag of this invention. FIG. 1 is a perspective view showing an example of a state in which two body films are superimposed on both sides of a bottom film. FIG. 2 is a diagram illustrating an example of a state in which a film is thermally welded. FIG. 3 is a perspective view showing a packaging bag precursor formed by superposing and welding the bottom film and the body film. FIG. 4 is a front view showing the bag body. Fig.5 (a) is a front view which shows a packaging bag. FIG.5 (b) is sectional drawing which follows the BB line of Fig.5 (a). FIG.5 (c) is sectional drawing which follows the CC line | wire of Fig.5 (a).

  As shown in FIGS. 5A, 5B, and 5C, the packaging bag 10 of the present embodiment has a folding portion 4a along the width direction of the packaging bag 10 (the left-right direction in FIG. 5A). 4 is formed on the upper portion of the packaging bag 10, and the packaging bag 10 has four sides of the body film 2, 3 stacked so as to sandwich the bottom film 4. 10 and the side seal portions 16 and 16 formed on both sides of the packaging bag 10 to form a storage space 7 for storing contents therein. A bag body 1 is provided.

As shown in FIG. 5 (b), the bag body 1 is provided with a spout 11 for communicating the storage space 7 with the outside of the bag body 1. The spout 11 has a base portion 11b and a cylindrical portion 11a protruding from the base portion 11b, and a cap 12 can be detachably attached to the cylindrical portion 11a. The spout 11 has the base 11b sandwiched between the upper edges 2a and 3a of the body films 2 and 3, and is thermally welded to the body films 2 and 3 by the upper seal portion 13 to It is fixed. A cylindrical portion 11 a of the spout 11 protrudes from the bag body 1 and can be opened and closed by a cap 12.
Further, as shown in FIG. 5 (c), reinforcing members 6 and 6 are interposed between the body films 2 and 3 on both sides of the bag body 1.

As the films used as the body films 2 and 3 and the bottom film 4, a base material such as a plastic film or a laminate film formed by laminating a plastic film with aluminum foil, paper, or the like can be used. The bottom film 4 may be the same type of base material as the body films 2 and 3 or may be a different base material.
Examples of the base material include a single-layer plastic film, a laminated film obtained by laminating multilayer plastics by coextrusion, a sheet of metal foil such as aluminum foil or paper, a laminate film obtained by laminating metal foil or paper, etc. with plastic, etc. Is exemplified.
The plastic film is not particularly limited, and examples thereof include polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon, and polyester resins such as polyethylene terephthalate. In particular, it is preferable that a sealant layer made of a thermoplastic resin having heat sealability is provided on one surface, and that the surface on the opposite side of the sealant layer does not show heat weldability under the condition of heat welding the sealant layer.

The base material can be provided with a gas barrier layer in order to provide a function of blocking a gas such as oxygen or water vapor as necessary. The gas barrier layer can be formed by coextrusion of an ethylene-vinyl alcohol copolymer (EVOH) layer or a polyvinylidene chloride resin layer, coating or laminating, or vapor deposition of metal or ceramic.
As for the thickness of a base material, 20-900 micrometers is preferable. A thicker base material is suitable in terms of shape retention and self-supporting properties of the bag, but a thinner base material is preferable in terms of flexibility and lightness. In particular, in the present invention, by providing the reinforcing member 6, shape retention and self-supporting properties can be ensured even with a thin base material. A particularly desirable thickness in terms of moldability and handleability is in the range of 100 to 200 μm.

The shape of the reinforcing member 6 is a shape along the side seal portion 16 of the bag body 1, and is a rod shape here. The reinforcing member 6 can be molded by various molding methods such as injection molding and extrusion molding. The reinforcing member 6 can be joined to the body films 2 and 3 by welding or adhesion. The material constituting the reinforcing member 6 is preferably a resin having at least a surface that contacts the body films 2 and 3 having heat-welding properties, such as various thermoplastic resins, engineering resins, blends with elastomers, and copolymer resins. Is available. The reinforcing member 6 may include a base material other than a resin such as a metal in the inside or the intermediate layer.
The reinforcing member 6 is preferably made of a thermoplastic resin that can be thermally welded to the body films 2 and 3, and the reinforcing member 6 can be joined to the body films 2 and 3 by heat welding. Examples of the thermoplastic resin constituting the reinforcing member 6 include polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon, and polyester resins such as polyethylene terephthalate. In particular, it is more preferable to select the same kind or the same resin as the thermoplastic resin constituting the sealant layer of the body films 2 and 3 as the thermoplastic resin constituting the reinforcing member 6 because a high bonding strength can be obtained.

The cross-sectional shape of the reinforcing member 6 may be various shapes such as a circular shape or a quadrangular shape shown in FIG.
In addition, as shown in FIG. 6, a groove 6 a along the longitudinal direction of the reinforcing member 6 can be provided on the side surface of the reinforcing member 6 on the side to be welded to the body films 2 and 3. In this case, it is possible to cut along the groove 6a when the reinforcing member 6 is cut in both directions, and the cutting can be performed with a small force. Moreover, since it can weld with the trunk | drum films 2 and 3 also in the groove | channel 6a, when it isolate | separates into each packaging bag, it can make a reinforcement member hard to drop off.
The thickness of the reinforcing member 6 is not particularly limited, but can be set to, for example, about 0.1 to 5.0 mm from the viewpoint of improving the shape retaining property and the self-supporting property of the bag body.

  The spout 11 is preferably formed from the same type or the same resin as the reinforcing member, that is, a thermoplastic resin that can be thermally welded to the body films 2 and 3, and can be directly heat welded to the body films 2 and 3. The spout 11 can be securely fixed to the bag body 1. An adhesive or the like may be used for fixing the spout 11.

In the packaging bag manufacturing method of this embodiment, as shown in FIGS. 1 to 3, two body films 2 and 3, and one bottom film superimposed between these body films 2 and 3. 4 forms a bag body of the packaging bag. The body films 2 and 3 and the bottom film 4 are long films, and the side portions of the bag body manufactured from the films are arranged along the direction (vertical direction in FIG. 1) perpendicular to the longitudinal direction of the film. It has come to be.
Here, the body films 2 and 3 are films having the same width. Reinforcing members 6, 6,... Are joined to one of the trunk films 2 among the trunk films 2 and 3 in advance at locations that become the sides of the packaging bag. The reinforcing members 6, 6,... May be alternately bonded to both the body films 2, 3.
A reinforcing member is provided on the upper portion of the opening 14 of the packaging bag so that the reinforcing member 6 does not exist at a position (see FIG. 5) where the sealing portion 13 is sealed after the contents are stored in the packaging bag. It is preferable to join the upper end of 6 apart from the upper end edges 2 a and 3 a of the body film 2 and 3. Thereby, when forming the upper seal part 13, both trunk | drum films 2 and 3 are joined more firmly.

The bottom film 4 is formed with a fold 4a along the longitudinal direction thereof. The folding part 4 a extends along the center part in the direction orthogonal to the longitudinal direction of the bottom film 4.
Here, the notch 4 c is formed so that the notch 4 c matches the position of the reinforcing member 6 when the body films 2 and 3 and the bottom film 4 are overlapped. By comprising in this way, the reinforcement member 6 and the two trunk | drum films 2 and 3 are joined more firmly. Further, at least a part of the bottom film 4 that contacts the reinforcing member 6 may be cut out by punching or the like so that both surfaces of the reinforcing member 6 are directly welded to the two body films 2 and 3. .

Next, as shown in FIGS. 1 and 2, the bottom film 4 is sandwiched between the two body films 2 and 3, and the body films 2 and 3 and the bottom film 4 are overlapped and thermally welded. In these films, both edges 4b and 4b of the bottom film 4 overlap with one edges 2b and 3b (lower edge of FIG. 2) of the body films 2 and 3, and the fold 4a of the bottom film 4 is overlapped. Are overlapped so as to face the inside of the direction perpendicular to the longitudinal direction of the body films 2 and 3.
As shown in FIG. 2, heat welding is performed by bringing heat sealing means (heating members) 31 and 32 into contact with the body film 2 or 3 of the body films 2 and 3 sandwiching the reinforcing member 6 from both sides or both sides. Accordingly, the reinforcing member 6 is also heated by heating.

As shown in FIG. 3, the body films 2 and 3, the bottom film 4, and the reinforcing member 6 are thermally welded to form a bottom seal portion 15 that becomes the bottom portion of the bag body, and side seal portions that serve as both side portions of the bag body. 16, the sheet-shaped packaging bag precursor 20 is obtained.
The side seal part 16 is formed along a direction orthogonal to the longitudinal direction of the body films 2 and 3. The side seal portion 16 heat-bonds the body films 2 and 3 to each other at the peripheral edge of the reinforcement member 6, but heats the reinforcement member 6 interposed between the body films 2 and 3 again. It may be welded. Although the width | variety of the part to which this trunk | drum film 2 and 3 was heat-welded is not specifically limited, For example, it is preferable to provide about 1-60 mm. By the side seal portion 16, the body films 2 and 3 are directly welded, the joint strength of the body films 2 and 3 in the bag body is improved, and a bag body without leakage or peeling is more reliably manufactured. Can do. When the bonding between the body films 2 and 3 and the reinforcing member 6 is airtight and strong, the side seal portion 16 can be omitted.

Next, the packaging bag precursor 20 of FIG. 3 is cut. Thereby, the bag 1 as shown in FIG. 4 is obtained. At this time, the reinforcing member 6 is cut in the longitudinal direction of the reinforcing member 6 by cutting along a direction orthogonal to the longitudinal direction of the film. Due to this cutting, the respective reinforcing members 6 that are cut into two become the reinforcing members 6 on the side portions of the bag body 1 adjacent to each other in the packaging bag precursor 20.
As shown in FIG. 6, when the reinforcing member 6 has a groove 6a along the longitudinal direction of the reinforcing member 6 on the side surface to be welded to the body films 2 and 3, the reinforcing member 6 along the groove 6a. Can be cut. Thereby, cutting can be made easy. Moreover, since it can weld with the trunk | drum films 2 and 3 also in the groove | channel 6a, when it isolate | separates into each packaging bag, it can make a reinforcement member hard to drop off.
Further, the spout 11 is sandwiched between the upper edges 2a and 3a of the body films 2 and 3, and the upper edges 2a and 3a and the spout 11 are heat-welded to form the upper seal portion 13, whereby the bag 1 The opening 14 is sealed. Thereby, the packaging bag 10 as shown in FIG. 5 is manufactured.

  The packaging bag 10 manufactured as described above is excellent in self-supporting property while being flexible when the bottom film 4 is opened. There are no particular limitations on the type of contents that can be stored in the packaging bag 10, but those having fluidity are suitable, and for example, liquids, viscous materials, powders, and small-diameter granular materials can be suitably stored. . Since the spout 11 that can be opened and closed is provided in the packaging bag 10, the remaining contents can be temporarily stored by sealing the spout 11 with the cap 12 after opening. The packaging bag 10 emptied after use of the contents can be easily reduced in volume by folding or rolling, so that it is excellent in disposal and suitable for environmental protection. By arranging the reinforcing members 6 on both sides of the bag, the shape retention and self-supporting properties of the packaging bag 10 are improved, and the packaging bag 10 is less likely to be bent in the middle. In addition, it is possible to easily pour out the contents by tilting the bag or to make the bag stand on its own, and to suppress leakage and spillage of the contents.

According to the manufacturing method of the packaging bag of this embodiment, since the reinforcing member is joined to the trunk film before the trunk film and the bottom film are overlapped, the reinforcing member can be reliably positioned. Therefore, it is possible to perform film superimposing work using an existing bag making machine, which is excellent in mass productivity. The reinforcing member may be joined to the body film offline in advance, and the reinforcing member may be previously joined to the body film, or after the body film is fed out on the bag making machine, the reinforcing member is attached to the body film. You may make it join.
Since the reinforcing members 6 are cut along the direction perpendicular to the longitudinal direction of the body films 2 and 3, the number of reinforcing members 6 joined to the body film 2 is the number of reinforcing members 6 required for the bag body 1. Thus, the labor required for positioning and joining of the reinforcing member 6 can be reduced, and productivity can be improved. Of course, two reinforcing members may be joined together as a set, and the reinforcing member may be cut. In this case, since only the film is cut, cutting becomes easy.
The portion where the side seal portion 16 thermally welds the body films 2 and 3 to each other at the peripheral edge of the reinforcement member 6 and again heat-welds the reinforcement member 6 interposed between the body films 2 and 3. If it contains, the joint strength of the whole trunk | drum films 2 and 3 in a bag body will improve, and the bag body without a leak and peeling can be manufactured more reliably.

Next, the 2nd form example of the manufacturing method of the packaging bag of this invention is demonstrated with reference to FIGS.
FIG. 7 is a front view showing the body film to which the reinforcing member is joined. FIG. 8 is a perspective view showing a packaging bag precursor formed by superposing and thermally welding the body film, bottom film, and body film of FIG. FIG. 9 is a cross-sectional view taken along the line SS of FIG. FIG. 10 is a front view showing a second embodiment of the packaging bag of the present invention.

  In the packaging bag manufacturing method according to the second embodiment, as shown in FIG. 7, the reinforcing member 8 with the spout formed by connecting the reinforcing members 6 and 6 to both sides of the base portion 11 b of the spout 11 is used. . The reinforcing member 8 with the spout is bent at the top (the spout 11 side) so that the width of the storage space of the packaging bag defined between the reinforcing members 6 and 6 becomes narrower toward the spout 11. It has a different shape. The reinforcing member 8 with the spout is joined to the body film 2 from one side at the base 11b of the spout 11 and the reinforcing members 6 and 6. A gap 9 is provided between each reinforcing member 8 with a spout.

Next, as shown in FIGS. 8 and 9, the bottom film 4 and the other body film 3 are superposed on the body film 2 to which the reinforcing member 8 with spout is joined, and these are heat-welded to seal the bottom. The part 15 and the side seal part 16 are formed. Here, the side seal portion 16 is provided so as to reach the base portion 11 b of the spout 11 along the reinforcing member 6. Thereby, the sheet-like packaging bag precursor 20 is obtained. The steps of film superposition and heat welding can be performed in the same manner as in the first embodiment.
The gap 9 between the reinforcing members 8 with the spout may be an unsealed portion 17 or may be welded without the body films 2 and 3 being welded.
Next, the packaging bag precursor 20 shown in FIG. 8 is cut into a packaging bag 10 as shown in FIG. In the cutting step, the unsealed portion 17 between the reinforcing members 6 is preferably removed, but may be left. When it is left, it is preferable to weld the body films 2 and 3.

In the manufacturing method of the present embodiment, the reinforcing member 6 is integrated with the spout 11 and can be molded at the same time. Compared with the manufacturing method of the first embodiment, the spout 11 is formed in the body film 2. , 3 can be omitted. Thereby, the number of processes can be reduced and productivity can be improved.
Further, since the reinforcing member 6 is integrally connected to the spout 11, the upper portion of the bag body 1 can be configured narrowly like a funnel toward the spout 11, and the contents from the spout 11 It becomes easy to take out.

As mentioned above, although this invention has been demonstrated based on suitable embodiment, this invention is not limited to the above-mentioned embodiment. The present invention can be variously modified without departing from the gist thereof.
For example, it is not always necessary to dispose the reinforcing member so as to extend over the bottom film. The reinforcing member is disposed only in the region where the bottom film of the side edge seal portion of the packaging bag does not exist, and directly on the two body films. It may be welded.
Further, in the above embodiment, a bottom film is arranged between two body films to produce a packaging bag, the bottom film is made the bottom of the packaging bag, and the opening of the packaging bag is between the body films. However, the present invention is not limited to this. For example, two bottom films are arranged between two body films so as to face each other to produce a packaging bag, and the bottom films are respectively a bottom portion and an upper end portion of the packaging bag. Good. In this case, it is preferable to provide a hole in the bottom film or the body film and weld a spout having a flange.

  The packaging bag manufactured by this invention can be utilized suitably for accommodation of a liquid, a viscous material, a powder, a small diameter granular material, etc.

In the 1st form example of the manufacturing method of the packaging bag of this invention, it is a perspective view which shows an example of a mode that two trunk | drum films are piled up on both sides of a bottom film. It is a figure which shows an example of a mode that a film is heat-welded. It is a perspective view which shows the packaging bag precursor formed by superposing | stacking a bottom part film and a trunk | drum film, and heat-welding. It is a front view which shows a bag body. (A) It is a front view which shows the 1st form example of the packaging bag of this invention. (B) It is sectional drawing which follows the BB line. (C) It is sectional drawing which follows CC line. It is sectional drawing which shows the modification of a reinforcement member. In the 2nd form example of the manufacturing method of the packaging bag of this invention, it is a front view which shows the trunk | drum film to which the reinforcement member was joined. It is a perspective view which shows the packaging bag precursor formed by superposing | stacking and thermally welding the trunk | drum film of FIG. 6, a bottom part film, and a trunk | drum film. It is sectional drawing which follows the SS line | wire of FIG. It is a front view which shows the 2nd example of a packaging bag of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Bag body, 2, 3 ... Body part film, 4 ... Bottom part film, 4a ... Folding part, 6 ... Reinforcement member, 11 ... Outlet, 10 ... Packaging bag, 16 ... Side part seal part.

Claims (4)

A bottom film formed with a fold along the longitudinal direction is sandwiched between two body films, and the two body films and the bottom film are heat welded along a direction perpendicular to the longitudinal direction of these films. Forming a portion to be a side portion of the packaging bag by making a packaging bag manufacturing method for making individual bags by cutting a portion to be the side portion of the packaging bag,
A step of joining a reinforcing member to at least one barrel film at a location that becomes a side portion of the packaging bag, and a trunk member that is joined to the trunk film and a trunk film in which the reinforcement member is not joined, and / or And a step of heat-welding the bottom film in this order.   The method for manufacturing a packaging bag according to claim 1, wherein when the portion to be a side portion of the packaging bag is cut, the reinforcing member is cut into two along a direction orthogonal to the longitudinal direction of the trunk film. .   Furthermore, the manufacturing method of the packaging bag of Claim 1 or 2 which has the process of heat-welding two trunk | drum film | membranes in the peripheral part of a reinforcement member.   The method for manufacturing a packaging bag according to any one of claims 1 to 3, wherein the reinforcing member is integrated with a spout of the packaging bag.

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