JP7378762B2 - Self-supporting containers and methods of manufacturing self-supporting containers - Google Patents

Description

The present invention relates to a self-supporting container made of plastic film and a method for manufacturing the same.

Patent Document 1 discloses that a cylindrical sheet is inflation-molded, and while both sides of the cylindrical sheet after inflation-molding are formed into a gusset shape, the flattened sheet facing surface is welded and cut along the bag outline line, thereby forming a gusset. It is a standing type bag in which the shaped part becomes the bottom and the cut widthwise middle part becomes the opening, and the part of the inflation-molded cylindrical sheet that becomes the bottom of the standing type bag is thin, and the opening part of the standing type bag is thin. The present invention discloses a standing bag in which the inflation-molded cylindrical sheet is also thin.

Patent No. 5619501

However, in the invention of Patent Document 1, since a standing bag is created with both sides of the inflation-molded cylindrical sheet as the bottom surface, the upper limit of the height of the standing bag is limited to the length of both sides of the inflation-molded cylindrical sheet. .
In addition, when manufacturing a low-height standing bag, either prepare an inflation-molded cylindrical sheet with short lengths on both sides, or discard the center part of the inflation-molded cylindrical sheet and use only both sides. Therefore, an increase in costs is inevitable.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide low-cost, self-supporting containers of various sizes and methods of manufacturing the same.

A self-supporting container according to an embodiment of the present invention includes a spout member for dispensing an internal liquid, an upper seal portion and a side seal portion disposed on one side and the other side with the mouth member as a boundary. a first film and a second film adhered to each other, and a bottom film formed of an extension of the first film, the bag body being able to stand on its own when placed on a horizontal surface with the bottom film facing down. and the bottom film is folded inward of the bag body so that the bottom film has a first edge and a second edge at a lower edge of the first film and a lower edge of the second film, respectively. a fold between the lower edge of the first film and the first edge of the bottom film is adhered to each other by a first bottom seal; The edge and the second edge of the bottom film are adhered to each other by a second bottom seal, and the end surface of the second bottom seal is such that the second film and the bottom film are bonded to each other by the seal. The end face of the first bottom seal portion is formed by folding the bottom film.

Further, the self-supporting container according to an embodiment of the present invention includes a spout member for pouring out the liquid inside, and an upper seal portion and a side disposed on one side and the other side with the spout member as a boundary. The film includes a first film and a second film that are adhered to each other by a sealing part, and a bottom film that is an extension of the first film, and is capable of standing on its own when placed on a horizontal surface with the bottom film facing down. the bottom film is folded inward of the bag body so that the bottom film has a first edge and a second edge at a lower edge of the first film and a lower edge of the second film, respectively. a fold between the lower edge of the first film and the first edge of the bottom film is bonded to each other by a first bottom seal portion; The lower edge and the second edge of the bottom film are bonded to each other by a second bottom seal, and the end surface of the second bottom seal includes the second edge of the first bottom seal. The boundary between the second film and the bottom film appears more clearly than the boundary between the first film and the bottom film.

In the method for manufacturing a self-supporting container according to an embodiment of the present invention, a main body film including a first film and a second film is arranged such that a part of the first film protrudes from the second film as an extension part. forming an upper seal portion by heat-sealing the first film and the second film; and a first peripheral edge of the first film and the second film that is continuous with the upper seal portion. forming a pair of first side seal parts by heat-sealing a part of the first film and the second peripheral part of the second film that are continuous with the upper seal part; The extension part of the first film is folded into a bellows shape with the first fold part and the second fold part along the upper seal part as boundaries, and the extension part is folded into the bottom part so that the second fold part is on the inside. a step of sandwiching the first film and the second film as a film; the remaining portions of the first peripheral edge and the second peripheral edge of the second film that are not heat-sealed; and the second fold line. forming a first lower side seal part by heat-sealing the bottom film on the second film side with the border at the second film side; and heating the first peripheral part and the second peripheral part of the first film. forming a second lower side seal portion by heat sealing the bottom film on the first film side with the remaining unsealed portion and the second fold portion as a boundary; and the first fold portion. a step of forming a first bottom seal portion by heat sealing the main body film; and forming a second bottom seal by heat sealing the lower edge of the second film and the edge of the bottom film.

According to this manufacturing method, since the bottom film is formed by folding the extension of the first film, there is no restriction that both sides of the cylindrical blown film are bottom films. Therefore, independent containers of various sizes can be produced regardless of the type of film used as the material for the bag body. As a result, it is possible to effectively utilize the film material and provide a self-supporting container at low cost.

In the method for manufacturing a self-supporting container according to an embodiment of the present invention, in the step of overlapping the first film and the second film, the main body film having a pair of peripheral edges facing each other is The method may include a step of overlapping the first film and the second film, which are separated by the third fold, by folding the third fold in a direction perpendicular to the third fold.

In the method for manufacturing a self-supporting container according to an embodiment of the present invention, a flat cylindrical inflation film having the pair of peripheral edge portions along the openings at one end and the other end in the axial direction is The method may further include a step of forming the main body film by cutting.
According to this method, a self-supporting container can be formed by processing a flat cylindrical blown film manufactured by a blown film extruder from a flat state. In other words, a self-supporting container can be formed using the blown film collected by the take-up roller of the existing blown film forming apparatus. Therefore, a self-supporting container can be manufactured from a single sheet of film without improving the blown film forming apparatus, so that an increase in cost can be suppressed.

Further, by adjusting the position when cutting the blown film along the axial direction, two types of main body films having different lengths can be obtained. As a result, two types of self-supporting containers with different sizes can be produced from one type of blown film.
Furthermore, the bottom film is not formed as a separate film from the main body film (the first film and the second film), but the main body film and the bottom film are integrally formed from one film. Therefore, also in this respect, a self-supporting container can be manufactured at a lower cost than when a self-supporting container is formed using at least two films.

Moreover, since a self-supporting container can basically be manufactured by folding and heat-sealing a blown film, it is possible to easily maintain sterility inside the bag body during manufacturing. As a result, a self-supporting container with high sterility can be manufactured.
In the self-supporting container according to an embodiment of the present invention, the side seal portion is disposed on the mouth member side of the bag body, and the first side seal portion has a two-layer structure of the first film and the second film. a seal part, a second side seal part continuous with the first side seal part, the bottom film folded to have a two-layer structure, the first film sandwiching the bottom film from both sides, and the bottom film. A second side seal portion having a four-layer structure with a second film may be included.

In the self-supporting container according to an embodiment of the present invention, the second bottom seal portion may include a hanging portion that is formed to selectively protrude and has a through hole for suspending the bag body. .
According to this configuration, the self-supporting container can be used by hanging it on a stand or the like.
The self-supporting container according to an embodiment of the present invention may include a medical self-supporting container in which a medical solution is housed in the bag body.

The method for manufacturing a self-supporting container according to an embodiment of the present invention includes, prior to the step of folding the extension part of the first film, applying heat to the first fold part and the second fold part to The method may further include the step of softening the film material of the first fold and the second fold.
According to this method, since the film material of the first fold portion and the second fold portion is softened, the step of folding the extension portion of the first film can be performed efficiently.

In the method for manufacturing a self-supporting container according to an embodiment of the present invention, the step of forming the first lower side seal portion includes forming the first lower side seal portion on the lower edge of the second film and the edge of the bottom film on the second film side. The method may include a step of forming the first lower side seal portion in a state in which the first lower side seal portion is shifted from the first lower side seal portion.
According to this method, when injecting liquid into the main body film, it is possible to easily open the space between the second film and the bottom film.

In the method for manufacturing a self-supporting container according to an embodiment of the present invention, the step of folding the extension part of the first film includes folding the extension part of the first film so that the overlapping part of the second film and the bottom film forms the second extension part. The step of forming the second bottom seal portion includes the step of folding the extension portion so as to protrude beyond the lower edge of the first film constituted by the first fold portion, and the step of forming the second bottom seal portion is for hanging the self-supporting container. The method may include a step of forming the second bottom seal part in a pattern having a hanging part having a through hole.

A method for manufacturing a self-supporting container according to an embodiment of the present invention includes stacking and heat-sealing the first lower side seal portion and the second lower side seal portion, thereby folding the container into a two-layer structure. The method may further include the step of forming a side seal portion having a four-layer structure of the bottom film, the first film and the second film sandwiching the bottom film from both sides.

FIG. 1 is a schematic perspective view of a self-supporting container according to an embodiment of the present invention. FIG. 2 is a schematic front view of a self-supporting container according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of a self-supporting container according to an embodiment of the present invention, and is a view taken along the line III--III in FIG. 2. FIG. 4 is a schematic cross-sectional view of a self-supporting container according to an embodiment of the present invention, and is a view taken along the line IV-IV in FIG. 2. FIG. 5 is a schematic bottom view of a self-supporting container according to an embodiment of the present invention. FIGS. 6A and 6B are diagrams showing a part of the manufacturing process of the self-supporting container. FIGS. 7A and 7B are diagrams showing the next step from FIGS. 6A and 6B. FIGS. 8A and 8B are diagrams showing the next step from FIGS. 7A and 7B. 9A and 9B are diagrams showing the next step from FIGS. 8A and 8B. FIGS. 10A and 10B are diagrams showing the next step from FIGS. 9A and 9B. FIGS. 11A and 11B are diagrams showing the next step from FIGS. 10A and 10B. FIG. 12 is a diagram showing the next step after FIGS. 11A and 11B. FIGS. 13A and 13B are diagrams showing the next step from FIGS. 11A and 11B. FIGS. 14A and 14B are diagrams showing the next steps of FIGS. 12, 13A, and 13B. 15A and 15B are diagrams showing the next step of FIGS. 14A and 14B. FIGS. 16A and 16B are diagrams showing the next step from FIGS. 15A and 15B. FIGS. 17A and 17B are diagrams showing a part of the manufacturing process of the self-supporting container. FIGS. 18A and 18B are diagrams showing the next step from FIGS. 17A and 17B. FIGS. 19A and 19B are diagrams showing the next step from FIGS. 18A and 18B.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
FIG. 1 is a schematic perspective view of a self-supporting container 1 according to an embodiment of the present invention. FIG. 2 is a schematic front view of a self-supporting container 1 according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of the self-supporting container 1 according to an embodiment of the present invention, and is a diagram showing the III-III cross section in FIG. 2. FIG. 4 is a schematic cross-sectional view of the self-supporting container 1 according to an embodiment of the present invention, and is a view taken along the line IV-IV in FIG. 2. FIG. 5 is a schematic bottom view of the self-supporting container 1 according to an embodiment of the present invention.

The self-supporting container 1 includes a bag body 2 that accommodates a liquid therein and can stand on its own when placed on a horizontal surface, and an opening member 3 for pouring out the liquid in a storage chamber 4 inside the bag body 2. . In this embodiment, the self-supporting container 1 is a medical self-supporting container 1 in which a medical solution 5 is accommodated in a storage chamber 4 .
The bag body 2 is formed using a plastic film. The material of the film used is not particularly limited as long as it is plastic, and examples include polyolefin resins such as polyethylene, polypropylene, poly(4-methylpentene), and polytetrafluoroethylene, and ethylene-tetracyclododecene. Examples include polycyclic olefin resins, preferably polyethylene and polypropylene. Polyolefin resins such as polyethylene and polypropylene have generally low elution properties with respect to various chemical solutions, and are general-purpose plastics. Therefore, elution of impurities into the chemical solution can be suppressed, and the cost of the bag body 2 can be reduced.

Moreover, the materials used for the film can be used alone or in combination of two or more. Moreover, the bag main body 2 may be formed in a single layer structure, or may be formed in a multilayer structure in which a plurality of resins are laminated.
Further, the thickness of the film used may be, for example, 150 μm to 300 μm. Further, the medicinal solution 5 accommodated in the storage chamber 4 may be, for example, a medical medicinal solution such as an infusion.

The bag main body 2 is arranged on one side and the other side (corresponding to the front side and the back side of the paper, respectively in FIG. 1) with the mouth member 3 as a boundary, and is sealed by an upper seal part 6 and a side seal part 7. It includes a first film 8 and a second film 9 that are adhered to each other, and a bottom film 10 that is an extension of the first film 8, and can stand on its own when placed on a horizontal surface with the bottom film 10 facing down. It has become.

The first film 8 and the second film 9 are each formed into a slightly elongated rectangular shape. The upper edges of the first film 8 and the second film 9 (the edges to which the mouth member 3 is attached) are closed by the upper seal portion 6.
The opening member 3 is fixed to the upper seal portion 6 by being sandwiched between the first film 8 and the second film 9.

The bottom film 10 is constituted by an extension of the first film 8. In other words, the bottom film 10 is a film that is distinguished from the first film 8 by the first bottom seal portion 20 (described below), but is a film that continues integrally from the first film 8.
As shown in FIG. 3, the bottom film 10 has a first edge 15 and a second edge 16 at the lower edge 13 of the first film 8 and the lower edge 14 of the second film 9, respectively. It is folded inward.

The bottom film 10 is folded in two so as to protrude into the storage chamber 4, and the folded part 17 is between one side seal part 7 and the other side seal part 7, as shown in FIG. It is formed over a period of time. As a result, a gusset-shaped bottom surface of the bag body 2 is formed, and the weight of the chemical solution 5 spreads the folds 17 of the bottom film 10, so that the bag body 2 can stand on its own.

Further, the bottom film 10 may have a first portion 18 on the first film 8 side and a second portion 19 on the second film 9 side, with the fold portion 17 as a boundary.
Furthermore, the fold between the lower edge 13 of the first film 8 and the first edge 15 of the bottom film 10 is bonded to each other by a first bottom seal portion 20 . On the other hand, the lower edge 14 of the second film 9 and the second edge 16 of the bottom film 10 are bonded to each other by a second bottom seal portion 21 .

As shown in FIG. 2, the first bottom seal part 20 and the second bottom seal part 21 are curved toward the outside of the storage chamber 4 so that their inner edges 22 have a dome shape that bulges outside the storage chamber 4. It is formed by Therefore, the width of the first bottom seal part 20 and the second bottom seal part 21 gradually decreases from both of the pair of side seal parts 7 toward the center of the first bottom seal part 20 and the second bottom seal part 21. It becomes narrower and has its minimum width in the center.

Further, a hanging portion 24 is formed in the second bottom seal portion 21, selectively protruding from the boundary portion 32 between the second film 9 and the bottom film 10, and having a through hole 23 for suspending the bag body 2. ing.
The side seal portion 7 includes a first side seal portion 25 and a second side seal portion 26 continuous with the first side seal portion 25.

As shown in FIG. 4, the first side seal portion 25 is disposed on the mouth member 3 side of the bag body 2 and has a two-layer structure of a first film 8 and a second film 9. On the other hand, the second side seal portion 26 has a four-layer structure including a bottom film 10 that is folded to have a two-layer structure, and a first film 8 and a second film 9 that sandwich the bottom film 10 from both sides. .
The mouth member 3 includes a cylindrical main body 27 and a rubber stopper 28 provided inside the main body 27.

The main body 27 is made of plastic, for example, and integrally includes a large diameter portion 29 having a relatively large diameter and a small diameter portion 30 having a smaller diameter than the large diameter portion 29. The rubber plug 28 is fitted into the small diameter portion 30 of the main body 27 so as to close the small diameter portion 30 .
In this embodiment, since the bottom film 10 of the bag body 2 is formed by folding the first film 8 which is integral with the bottom film 10, the end surface condition of each heat-sealed portion is not uniformly the same.

In other words, when the first film 8, the second film 9, and the bottom film 10 are separate films, the heat-sealed portion is formed at the overlapping portion of the edges of at least two films. administered. Therefore, the end surface state of the heat-sealed portion is such that the boundary between at least two films clearly appears. In this embodiment, as shown in FIG. 5, the second bottom seal portion 21 is not connected at the crease, but is connected to the lower edge 14 of the second film 9 and the second edge 16 of the bottom film 10. It is applied to the overlapping parts. Therefore, the boundary 32 between the second film 9 and the bottom film 10 clearly appears.

On the other hand, the first bottom seal portion 20 is applied to the fold between the lower edge 13 of the first film 8 and the first edge 15 of the bottom film 10. Therefore, the boundary portion 33 between the first film 8 and the bottom film 10 does not appear as clearly as the second bottom seal portion 21 does. In other words, the boundary part 32 between the second film 9 and the bottom film 10 appears more clearly on the end face 34 of the second bottom seal part 21 than the boundary part 33 of the end face 35 of the first bottom seal part 20. There is. For example, the boundary portion 32 of the second bottom seal portion 21 may be exposed and clearly visible at the end surface 34 thereof, and the boundary portion 33 of the first bottom seal portion 20 may not be exposed from the end surface 35 thereof and be clearly visible. It may be so thin that it can be visually recognized on the back side of 35 (on the storage chamber 4 side).

Similarly, the upper seal portion 6 and the side seal portion 7 are both applied to the overlapping portions of the edges of the first film 8, the second film 9, and the bottom film 10. Therefore, as shown in FIG. 1, boundaries 38 and 39 between the first film 8, second film 9, and bottom film 10 are clearly defined on the end surface 37 of the upper seal section 6 and the end surface 36 of the side seal section 7, respectively. It appears in

6A and 6B to FIG. 16A and 16B are diagrams showing a part of the manufacturing process of the self-supporting container 1 in the order of the steps. Note that the cross-sectional views shown in FIGS. 6A and 6B to 16A and 16B do not show cross-sections at specific positions of the self-supporting container 1, but preferentially show the necessary configuration for convenience of explanation. This is a diagram.
To manufacture the self-supporting container 1, first, as shown in FIGS. 6A and 6B, a first film 8 and a second film 9 that is shorter than the first film 8 are separated so that a part of the first film 8 They are overlapped so as to protrude from the second film 9 as an extension part 58. The first film 8 and the second film 9 are main body films 56 that constitute the bag main body 2 of the self-supporting container 1, and have a first peripheral portion 44 and a second peripheral portion 45 facing each other.

Next, as shown in FIGS. 7A and 7B, the opening member 3 is sandwiched between the first film 8 and the second film 9 at the peripheral edge 57 of the first film 8 and the second film 9. Then, the upper sealed portion 6 is formed by heat-sealing the peripheral edge portions 57 of the first film 8 and the second film 9.
Next, as shown in FIGS. 8A and 8B, a portion of the first peripheral edge portion 44 of the first film 8 and the second film 9 and a portion of the second peripheral edge portion 45 of the first film 8 and the second film 9 are removed. part is heated in a mold 61.

As a result, the first film 8 and the second film 9 are heat-sealed, and the upper seal portion 6 and the first side seal portion 25 continuous to the upper seal portion 6 are formed. Note that the upper seal portion 6 and the pair of first side seal portions 25 may be formed at the same time in terms of manufacturing efficiency.
Next, as shown in FIGS. 9A and 9B, a first fold section 59 and a second fold section 60 are formed at predetermined positions closer to the extension section 58 than the first side seal section 25 of the first film 8. . The first fold portion 59 is formed in a region of the first film 8 facing the second film 9 , and the second fold portion 60 is formed in the extension portion 58 of the first film 8 .

More specifically, the first film 8 is selectively heated with the mold 63 along the upper seal portion 6, thereby softening the film material. As a result, a linear first fold section 59 and a second fold section 60 extending from one end of the first film 8 in the width direction to the other end are formed. Note that when the main body film 56 is made of a relatively thin film, the film material of the first fold section 59 and the second fold section 60 does not need to be softened.

Next, as shown in FIGS. 10A and 10B, the extension part 58 of the first film 8 is folded into a bellows shape with the first fold part 59 and the second fold part 60 as boundaries, and the second fold part 60 is on the inside. The bottom film 10 is sandwiched between the first film 8 and the second film 9 so that the bottom film 10 is sandwiched between the first film 8 and the second film 9. At this time, if the film material of the first fold section 59 and the second fold section 60 has been softened in the previous step, the step of folding the extension section 58 of the first film 8 can be performed efficiently.

In addition, in this step, the overlapping portion of the second film 9 and the bottom film 10 is formed as a second extension portion 62 so as to protrude (protrude) from the lower edge 13 of the first film 8 constituted by the first fold portion 59. ), the extension 58 of the first film 8 is folded.
Next, as shown in FIGS. 11A and 11B, the remaining portions of the first peripheral edge 44 and second peripheral edge 45 of the second film 9 that are not heat-sealed and the second portion 19 of the bottom film 10 are made of gold. It is heated in a mold 69. As a result, the second film 9 and the bottom film 10 are heat-sealed, and a first lower side seal portion 64 continuous to the first side seal portion 25 is formed.

At this time, the lower edge 14 of the second film 9 and the second edge 16 of the bottom film 10 are shifted (for example, the second edge 16 of the bottom film 10 is lower than the lower edge 14 of the second film 9). It is preferable to form the first lower side seal portion 64 in a protruding state. Thereby, when injecting the chemical solution 5 into the inside of the main body film 56, which will be described later, the space between the second film 9 and the bottom film 10 can be easily opened. The work of shifting the second film 9 and the bottom film 10 may be performed in the folding process of the extension portion 58 of the first film 8 described above.

Further, as shown in FIG. 11B, if a heat shield plate 65 is inserted between the first part 18 and the second part 19 of the bottom film 10 during heat sealing, the heat from the mold 69 can be shielded. Since it can be blocked by the plate 65, the first film 8 and the first portion 18 of the bottom film 10, which do not need to be heat-sealed in this step, can be prevented from being heat-sealed.
Next, as shown in FIG. 12, FIG. 13A and FIG. , and the first fold portion 59 are heated by the mold 71. As a result, the first film 8 and the bottom film 10 are heat-sealed, and the second lower side seal portion 66 and the first bottom seal portion 20 are simultaneously formed. Although the second lower side seal portion 66 and the first bottom seal portion 20 were formed at the same time for reasons of manufacturing efficiency, they may also be formed in separate steps using separate molds.

During this heat sealing, as shown in FIGS. 13A and 13B, if a heat shield plate 67 is inserted between the first part 18 and the second part of the bottom film 10, the heat from the mold 71 can be prevented. This can be blocked by the heat shield plate 67, and unnecessary heat can be prevented from being transmitted to the second portion 19 side of the bottom film 10. In particular, in this step, it is necessary to maintain an opening for injecting the chemical solution 5 without heat-sealing the space between the lower edge 14 of the second film 9 and the second edge 16 of the bottom film 10. Therefore, it is preferable to use the heat shield plate 67.

Next, as shown in FIGS. 14A and 14B, the chemical solution 5 is injected into the main body film 56 from the opening 68 between the lower edge 14 of the second film 9 and the second edge 16 of the bottom film 10. Ru.
Next, as shown in FIGS. 15A and 15B, the lower edge 14 of the second film 9 and the second edge 16 of the bottom film 10 are heated in the mold 72. Thereby, the second film 9 and the bottom film 10 are heat-sealed, and the second bottom seal portion 21 is formed. At this time, the second bottom seal part 21 is formed in a pattern having a hanging part 24 having a through hole 23 in the second extension part 62 . Thereafter, the second film 9 and the bottom film 10 other than the second bottom seal part 21 and the hanging part 24 are removed by punching.

Also, during this heat sealing, as shown in FIG. 15B, if a heat shield plate 70 is inserted between the first part 18 and the second part 19 of the bottom film 10, the heat from the mold 72 can be prevented. This can be blocked by the heat shield plate 70, and unnecessary heat can be prevented from being transmitted to the first portion 18 side of the bottom film 10.
Next, as shown in FIGS. 16A and 16B, the first lower side seal part 64 and the second lower side seal part 66 are overlapped and heated with a mold 73. As a result, the first lower side seal part 64 and the second lower side seal part 66 are heat-sealed, and the second side seal part 26 is formed. Through the above steps, the above-mentioned self-supporting container 1 is obtained.

According to the above method, the bottom film 10 is formed by folding the extension portion 58 of the first film 8 (see FIG. 10A). Therefore, unlike the conventional method, there is no restriction that both sides of the cylindrical blown film are bottom films. Therefore, independent containers 1 of various sizes can be manufactured regardless of the type of film used as the material for the bag body 2. As a result, it is possible to effectively utilize the film material and provide a self-supporting container at low cost.

Note that the self-supporting container 1 may be made from two films, the first film 8 and the second film 9, but it can also be made from one blown film.
In that case, first, as shown in FIGS. 17A and 17B, a first mark 41 and a second mark 42 are provided on a flat cylindrical inflation film 40. The first mark 41 and the second mark 42 may be, for example, a mouth member adhered to the inflation film 40 by a known means such as thermal welding or ultrasonic welding.

More specifically, the inflation film 40 has a first peripheral edge 44 along the opening 43 on one end in the axial direction, and a third peripheral edge 46 and a fourth peripheral edge 47 orthogonal to the first peripheral edge 44. It is folded in two so that the third peripheral edge part 46 and the fourth peripheral edge part 47 form creases. The third peripheral edge 46 and the fourth peripheral edge 47 face each other in the width direction of the blown film 40.

Then, on the outer surface 49 on one side of the blown film 40, a first mark is placed in a first region 51 closer to the third peripheral edge 46 than the intermediate part 48 between the third peripheral edge 46 and the fourth peripheral edge 47. 41 is provided. On the other hand, the second mark 42 is a second region on the other side outer surface 50 of the blown film 40 that is closer to the fourth peripheral edge 47 than the intermediate part 48 between the third peripheral edge 46 and the fourth peripheral edge 47. 52. The first mark 41 and the second mark 42 are provided in order along the length direction of the blown film 40 at predetermined intervals.

Thereafter, the inflation film 40 is cut along the width direction so that one first mark 41 and one second mark 42 are included. As a result, a blown film 40 having one first mark 41 and one second mark 42 is obtained. The cut out blown film 40 includes a second peripheral edge 45 that extends along the opening 53 on the other end in the axial direction and faces the first peripheral edge 44 in the axial direction of the expanded film 40 .

Next, as shown in FIGS. 18A and 18B, the blown film 40 is cut into a first body film 54 and a second body film 55, each including a first mark 41 and a second mark 42.
More specifically, the inflation film 40 is cut so as to separate the first region 51 and the second region 52 along the intermediate portion 48, for example. As a result, a first body film 54 having the first mark 41 and a second body film 55 having the second mark 42 are obtained. In addition, below, the 1st main body film 54 provided with the 1st mark 41, and the 2nd main body film 55 provided with the 2nd mark 42 are collectively demonstrated as the main body film 56.

Next, as shown in FIGS. 19A and 19B, the first film 8 and the second film 9 of the main body film 56, which are separated by the predetermined third fold 74 as a boundary, are separated into one part of the first film 8. The second film 9 is overlapped so that the second film 9 protrudes from the second film 9 as an extension part 58.
In this embodiment, in the steps of FIGS. 17A and 17B, the first mark 41 and the second mark 42 are attached at positions spaced inward from the third peripheral edge 46 and fourth peripheral edge 47 of the inflation film 40. With the positions of the first mark 41 and the second mark 42 as boundaries, the area is divided into a region where the distance from the position to the cutting portion (intermediate portion 48) is long and a region where the distance is short. Therefore, by folding the main body film 56 with the positions of the first mark 41 and the second mark 42 as the third fold portion 74, the long region of the main film 56 can be easily used as the first film 8 and the short region as the second film 9. can be distinguished.

The third fold part 74 of the first film 8 and the second film 9, a part of the first peripheral part 44 of the first film 8 and the second film 9, and the second fold part 74 of the first film 8 and the second film 9 A portion of the peripheral portion 45 is heated by the mold 61.
As a result, the first film 8 and the second film 9 are heat-sealed, and the upper seal portion 6 and the first side seal portion 25 continuous to the upper seal portion 6 are simultaneously formed. Although the upper seal portion 6 and the pair of first side seal portions 25 were formed at the same time for reasons of manufacturing efficiency, they may also be formed in separate steps using separate molds.

After that, the self-supporting container 1 is obtained by going through the same steps as in FIGS. 9A, 9B to 16A, 16B.
According to the above method, the self-supporting container 1 can be formed by processing the flat cylindrical blown film 40 manufactured by the extruder for the blown film 40 from a flat state.

That is, the self-supporting container 1 can be formed using the blown film 40 collected by the take-up roller of the existing blown film forming apparatus. Therefore, the self-supporting container 1 can be manufactured from one sheet of film without improving the blown film forming apparatus, so that an increase in cost can be suppressed.
Moreover, by adjusting the position when cutting the inflation film 40 along the axial direction, two types of main body films 54 and 55 having different lengths can be obtained. For example, if the cutting position is shifted toward the fourth peripheral edge 47 side than the intermediate part 48, as in the position of the cutting line 75 in FIG. 18A, the first main body film 54 can be obtained which is relatively long on the third peripheral edge part 46 side. Therefore, it is possible to obtain the second main body film 55 which is relatively shorter than the first main body film 54 on the fourth peripheral edge portion 47 side. As a result, two types of self-supporting containers 1 having different sizes can be produced from one type of blown film 40.

Further, the bottom film 10 is not formed as a separate film from the main body film 56 (first film 8 and second film 9), but the main body film 56 and the bottom film 10 are integrally formed from one film. be done. Therefore, also in this respect, the self-supporting container 1 can be manufactured at a lower cost than when the self-supporting container 1 is formed using at least two films.

Moreover, since the self-supporting container 1 can basically be manufactured by folding and heat-sealing the inflation film 40, it is possible to easily maintain the sterility inside the bag body 2 during manufacturing. As a result, a self-supporting container 1 with high sterility can be manufactured.
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other forms.

For example, the method for manufacturing the self-supporting container 1 including the steps shown in FIGS. 17A, 17B to 19A, 19B may be performed using two sheets obtained by other film forming methods, such as T-die forming, instead of the blown film 40. It can also be performed in the same manner as the blown film 40 after the films are bonded together.
For example, the liquid contained in the self-supporting container 1 may be a drink or the like in addition to the medical solution 5.

In addition, various design changes can be made within the scope of the claims.

1 Self-supporting container 2 Bag body 3 Mouth member 4 Storage chamber 5 Chemical solution 6 Upper seal portion 7 Side seal portion 8 First film 9 Second film 10 Bottom film 13 Lower edge (of the first film) 14 (of the second film) Lower edge 15 First edge (of the bottom film) 16 Second edge (of the bottom film) 17 Fold section 18 First section (of the bottom film) 19 Second section (of the bottom film) 20 First bottom seal section 21 Second bottom seal portion 22 Inner edge 23 Through hole 24 Hanging portion 25 First side seal portion 26 Second side seal portion 27 Main body 28 Rubber plug 29 Large diameter portion 30 Small diameter portion 31 Space 32 Boundary (of second bottom seal portion) Part 33 Boundary part (of the first bottom seal part) 34 End face (of the second bottom seal part) 35 End face (of the first bottom seal part) 36 End face (of the side seal part) 37 End face (of the upper seal part) 38 ( Boundary part (of the upper seal part) 39 Boundary part (of the side seal part) 40 Inflation film 41 First mark 42 Second mark 43 Opening (of the blown film) 44 First peripheral part (of the blown film) 45 First peripheral part (of the blown film) 2 periphery 46 3rd periphery (of the blown film) 47 4th periphery (of the blown film) 48 Intermediate portion 49 Outer surface on one side 50 Outer surface on the other side 51 1st region 52 2nd region 53 (inflated film) ) Opening 54 First main body film 55 Second main body film 56 Main film 57 Peripheral part 58 Extension part (of the first film) 59 Second fold part 60 Third fold part 61 Mold 62 Second extension part 63 Mold 64 First lower side seal portion 65 Heat shield plate 66 Second lower side seal portion 67 Heat shield plate 68 Opening 69 Mold 70 Heat shield plate 71 Mold 72 Mold 73 Mold 74 Third fold portion 75 Cutting line

Claims (7)

overlapping a main body film including a first film and a second film so that a portion of the first film protrudes from the second film as an extension;
forming an upper seal portion by heat-sealing the first film and the second film;
A portion of the first periphery of the first film and the second film that are continuous to the upper seal portion, and a portion of the second periphery of the first film and the second film that are continuous to the upper seal portion. forming a pair of first side seal portions by heat sealing;
The extension part of the first film is folded into a bellows shape with the first fold part and the second fold part along the upper seal part as boundaries, and the extension part is folded into the bottom part so that the second fold part is on the inside. sandwiching the film between the first film and the second film;
By heat-sealing the remaining portions of the first peripheral edge and the second peripheral edge of the second film that are not heat-sealed, and the bottom film on the second film side with the second fold portion as a boundary. forming a first lower side seal portion;
By heat-sealing the remaining portions of the first peripheral edge and the second peripheral edge of the first film that are not heat-sealed, and the bottom film on the first film side with the second fold as a boundary. forming a second lower side seal portion;
forming a first bottom seal portion by heat sealing the first fold portion;
Injecting a liquid into the inside of the main body film from an opening between the lower edge of the second film and the edge of the bottom film on the second film side;
forming a second bottom seal by heat sealing the lower edge of the second film and the edge of the bottom film. The step of overlapping the first film and the second film includes folding the main body film, which has a pair of peripheral edges facing each other, at a third crease in a direction perpendicular to the pair of peripheral edges. The method for manufacturing a self-supporting container according to claim 1 , comprising the step of overlapping the first film and the second film, which are separated by a third fold. The method further comprises the step of: forming the main body film by cutting along the axial direction a flat cylindrical inflation film having the pair of peripheral edges along openings at one end and the other end in the axial direction. Item 2. A method for producing a self-supporting container according to item 2 . Prior to the step of folding the extension of the first film, the film material of the first fold and the second fold is softened by applying heat to the first fold and the second fold. The method for manufacturing a self-supporting container according to any one of claims 1 to 3 , further comprising the step of: The step of forming the first lower side seal portion includes forming the first lower side seal portion in a state where the lower edge of the second film and the edge of the bottom film on the second film side are shifted. The method for producing a self-supporting container according to any one of claims 1 to 4 , comprising the step of: The step of folding the extension part of the first film is such that the overlapping part of the second film and the bottom film becomes a second extension part, which is larger than the lower edge of the first film constituted by the first fold part. folding the extension so that it protrudes;
The step of forming the second bottom seal portion includes the step of forming the second bottom seal portion in a pattern having a hanging portion having a through hole for hanging the self-supporting container. 5. A method for manufacturing a self-supporting container according to any one of 5 . The first lower side seal part and the second lower side seal part are overlapped and heat-sealed to form a folded two-layer structure, and the bottom film is sandwiched between the bottom film from both sides. The method for manufacturing a self-supporting container according to any one of claims 1 to 6 , further comprising the step of forming a side seal portion having a four-layer structure including a first film and the second film.

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