JP3248469U - Bag-shaped container - Google Patents

Abstract

[Problem] To provide a bag-like container that can be opened without any trouble even if the cutting line accidentally enters the side edge of the tear strip when forming a gripping portion at the end of the tear strip with a cutting blade. [Solution] The bag-like container has a bag body that forms a storage space by folding or overlapping a rectangular film, and a long tear strip 2a arranged on the back side of the film, and the tear strip has a gripping portion formed by cutting the film with a cutting line 3 so that the film has two ends on the outside of both edges of the tear strip in the width direction of the tear strip, and the user holds the gripping portion and lifts the tear strip to cut and open the bag body, and the bag-like container is characterized in that a security cutting portion 5 is formed by cutting the film near the end of the cutting line, and the security cutting portion is formed on the outside in the width direction of the tear strip, and on the back side of the film, the cutting portion is covered with an airtight sheet 6 to ensure airtightness of the storage space. [Selected Figure] Figure 2

Description

This invention relates to a bag-shaped container that is opened using a tear strip, and that allows the tear strip to be pulled up reliably even if there is a deviation in the position of the cut formed around the gripping portion formed at the end of the tear strip.

In recent years, pouch-shaped containers that can be opened by cutting the surface of the container using a tear strip have come into widespread use. Until the surface of the container is torn using the tear strip, the composite film that constitutes the pouch-shaped container minimizes the effects of outside air and light on the contents of the container, so that the contents can be reliably prevented from deteriorating due to oxidation or other reasons during transportation or long-term storage.

In addition, a structure has been proposed in which zipper tape is placed in parallel with the tear strip, allowing the bag-like container to be reopened once opened, and the contents of the bag-like container can be dispensed in small amounts while still maintaining its quality for a specified period of time after opening and closing.

The following conventional technology is an example of this type of bag-shaped package:

Patent Publication No. 2018-188196 Patent Publication No. 2023-157728

The bag-shaped container of Patent Document 1 has a structure in which a tear strip (tear guide strip) 21 is attached to the back surface 11A of the bag-shaped container, and a cutting line 30 is formed on the surface 11A of the film constituting the bag-shaped container so as to surround one end of the tear strip, thereby forming a gripping portion (pinch portion) 3 of the tear guide strip 21 in this portion. The user then grips this gripping portion 3 and pulls the tear strip 21 outward through the film of the bag-shaped container, thereby tearing the surface 11A and opening the container.

In addition, the bag-shaped container of Patent Document 2 also has a long member 120, which is formed by attaching a tear strip (tear strip) 122 to a base strip 121 and integrating it with the base strip 121, joined to the surface 111A of the bag-shaped container 100. As in Patent Document 2, a C-shaped cut is formed around one end of the tear strip 122, and the inside becomes a gripping portion (tab) 130, and by pulling up this gripping portion 130, the surface 111A of the film of the bag-shaped container 100 is cut to open the container.

The bag-shaped containers in both documents have zipper tape (reference numbers 601 and 612 in Patent Document 1, and reference numbers 124A and 124B in Patent Document 2) laid in parallel with the tear strip (tear guide strip 21 in Patent Document 1, and tear strip 122 in Patent Document 2), so that once the bag-shaped container has been opened with the tear strip, it can be resealed with the zipper tape and opened again.

All tear strips have a cut line (notch) formed at one end to form a gripping portion (pinch portion 3 in Patent Document 1, tab 130 in Patent Document 2). However, if the relative position of the cutting blade and the bag body is misaligned during the process of forming the cut line on the bag-shaped container, one end of the cutting blade may go beyond the edge of the tear tape and cut into the inside of the tear tape (see Figure 3(a)).

Here, when the tear strip is pulled up, the bag body is torn by twisting between the material of the bag body that is fixed to the edge of the tear strip being pulled up and the material on the outside of that, creating a stress concentration point at this point, which causes the material of the bag body to be twisted off (see P1 in Figure 3(b)).

However, as mentioned above, if one end of the cut line goes inside the tear strip, the material of the bag body will not twist and a stress concentration point will not form between the materials of the bag body, resulting in a defective product when opened (see P2 in Figure 3(b)).

In particular, this opening and closing defect can occur even with extremely minute positioning errors of just a few tenths of a millimeter at the end of the cutting line, making it difficult to remove products that have been opened with defects through visual inspection. In order to detect such defects, machine-based image recognition is required, which requires a large investment.

The purpose of this invention is to provide a structure that, during the manufacturing process of a bag-shaped container with a tear strip attached, does not interfere with opening the bag-shaped container with the tear strip even if the cutting line accidentally enters the side edge of the tear strip when a cutting blade is used to form a gripping portion at the end of the tear strip.

To achieve the above object, the bag-shaped container of the present invention has a bag body that forms a storage space by folding or overlapping a rectangular film, and a long tear strip that is placed on the back side of the film, and the tear strip has a gripping portion formed by a cutting line that cuts the film so that the tear strip has two ends on the outside of both edges of the tear strip in the width direction of the tear strip, and the user holds the gripping portion and lifts the tear strip to cut and open the bag body. In this bag-shaped container, a security cut portion is formed by cutting the film near the end of the cutting line, and the security cut portion is formed on the outside in the width direction of the tear strip, and on the back side of the film, the cut portion is covered with an airtight sheet, ensuring the airtightness of the storage space.

With the bag-shaped container of this invention, even if the positioning of the cut line and the bag body is misaligned during the process of forming a cut line at the end of the tear strip to form a gripping portion, and the end of the cut line overlaps the edge of the tear strip, when the user pulls up the tear strip, the safety cut portion formed near the end of the cut line becomes the starting point of a new stress concentration point, allowing the bag-shaped container to be opened smoothly.

1 is a front view of a bag-shaped container according to a first embodiment of the present invention; FIG. 2 is an enlarged view of part A in FIG. 13A and 13B are explanatory diagrams showing a situation in which defects in opening a conventional bag-shaped container occur. 5A and 5B are explanatory diagrams showing the function of the security cut-off line in the bag-shaped container of the present embodiment. 4(a), (b), and (c) are explanatory diagrams showing other embodiments of the present invention.

First Embodiment
The structure of a first embodiment of a bag-shaped container according to the present invention will be described with reference to Figures 1 and 2. Figure 2 is an enlarged view of area A in Figure 1.

As shown in FIG. 1, the structure of the bag-shaped container 1 of this embodiment is formed by the following process. That is, the left and right ends of a rectangular film are folded back to the back side and joined together by a method such as heat welding to form a back joint 11, and a cylindrical body is formed by polymerizing the front film 1A and the back film 1B.

Then, the lower end of the cylindrical body is joined by heat welding or the like to form a lower end joint 13, forming a storage space between the front film 1A and the back film 1B. After the items to be stored, such as food or medicine, are placed into this storage space from the open top end, the top end is similarly joined by heat welding or the like to seal the storage space.

The film that constitutes the bag-shaped container 1 has a gas barrier layer. This gas barrier layer is produced by coating the surface of a base material such as PET, oriented nylon (ONy), oriented polypropylene (OPP), or unoriented polypropylene (CPP) with silica or alumina, which can be formed into a transparent and extremely thin film, by vapor deposition. As a result, the contents in the storage space are protected from air and light until they are opened, allowing for long-term storage.

In addition, a transparent sealant layer made of low density polyethylene (LDPE), linear polyethylene (LLDPE), or concentrated polyethylene (CPP) is formed on top of the gas barrier layer. During the manufacturing process of the bag-shaped container described above, these sealant layers are heat-sealed to each other and to the tear tape 7 and zipper tape 8 described below.

As shown in Figures 1 and 2, a tear tape 7 is fixed to the back side of the surface film 1A of the bag-shaped container 1 so that the surface film 1A can be torn with a tear strip 2a to open the bag-shaped container.

This tear tape 7 is an integrated product of a long tear strip 2a and a base strip 2b that holds the tear strip 2a in a groove (not shown) on the surface. This tear tape 7 is positioned and welded to the area corresponding to the surface 1A before the process of the bag-shaped container 1 described above, and the top surfaces of the tear strip 2a and base strip 2b are independently fixed to the sealant layer on the surface of the storage space of the bag-shaped container 1.

In order to improve the separability between the tear strip 2a and base strip 2b, one is made of a low-density polyethylene resin, and the other is made of a resin that has low compatibility with low-density polyethylene, such as a random polypropylene resin.

Near one end 2c of the tear strip 2a, a C-shaped cut line 3 is formed that penetrates the surface 1A of the bag-like container 1 from the front side to the back side. This cut line 3 starts near the upper edge of the tear strip 2a at 3a, descends in an ascending arc in a mountain shape, crosses the end 1c side of the tear strip 2a, forms a symmetrical mountain shape at the top, and ends near the lower edge of the tear strip 1a at 3b.

The area surrounded by this cutting line 3 becomes the gripping portion 4 of the tear strip 2a, and the user can lift the gripping portion 4, pinch it, and pull the tear strip 2a up from the base strip 2b to tear the surface 1A of the bag-like container 1 and open the bag-like container 1.

In addition, a pair of guaranteed cutting lines (guaranteed cutting portions) 5 (5a, 5b) are formed near the ends 3a, 3b of the cutting line 3. The guaranteed cutting lines 5 are short, straight cutting lines formed along the direction in which the gripping portion 4 is pulled up, and do not overlap the ends 3a, 3b of the cutting line in the width direction of the tear strip 2a. They are positioned farther away than the ends 3a, 3b of the cutting line 3, so that the distance L2 between the pair of guaranteed cutting lines 5a, 5b is set to be greater than the distance L1 between the ends 3a, 3b of the cutting line 3.

The security cut line 5 is formed at the same time as the cut line 3 using a punching die, but the punching die is made up of a combination of a Thomson blade, which is made of a separate fixed blade body and cuts the cut line 3, and a Pinnacle blade (registered trademark) which can be processed into a fine shape by etching and cuts the security cut lines 5a and 5b (the choice between a Thomson blade and a Pinnacle blade is made appropriately depending on durability, etc.). The effects of the security cuts 5a and 5b will be described later.

At the position of the gripping portion 4, an airtight sheet 6 is attached to the back side of the surface film 1A of the bag-shaped container 1. This airtight sheet 6 has a square welded area 6a that crosses the tear strip 2a and surrounds the gripping portion 4, and the cutting line 3 and the guaranteed cutting line 5 isolate the area 6b that communicates with the outside air from the inside of the bag-shaped container 1, thereby maintaining the airtightness of the storage space of the bag-shaped container 1.

The bag-shaped container 1 also has a zipper tape 8 laid below and parallel to the tear strip 2a (tear tape 7). The zipper tape 8 is composed of a protrusion 8a fixed to the back side of the surface film 1A of the bag-shaped container, and a groove 8b fixed to a sealing sheet (not shown) that covers the opening portion of the surface film 1A by the tear strip 2b.

By repeatedly engaging and separating the ridges 8a and grooves 8b of the zipper tape 8, a bag-like container that has been opened once with a tear strip can be resealed and reopened.

The effects of this embodiment will be explained using Figures 3 and 4. Figure 3 shows a conventional bag-shaped container 1 that does not have a guaranteed cut line 5, unlike this embodiment, and Figure 4 shows the bag-shaped container 1 of this embodiment that has a guaranteed cut line 5.

First, as shown in FIG. 3(a), in a conventional bag-shaped container 1, if the relative position between the surface film 1A of the bag-shaped container 1 and the punch die for forming the cutting line 3 is misaligned during the process of forming the cutting line 3, for example, one end 3b of the cutting line 3 may be formed by being embedded inward from the lower edge of the tear strip 2a.

In this state, when the tear strip 2a is pulled up using the grip 4, the stress concentration point P1 of the other end 3a of the cutting line 3 is on the film 1b (on the upper edge 2b of the base) outside the tear strip 2a, so the surface film 1a welded to the upper surface of the tear strip 2a and the film 1b welded to the upper surface of the base strip 2b beside it are twisted, and the surface film 1A is torn along the edge of the tear strip 2a.

However, if the end 3b is formed on the inside of the tear strip 2a, the stress concentration point P2 will not cause a twist between the film 1a on the tear strip 2a and the film 1b on the base strip 2b. As a result, the surface film 1A of the bag-shaped container 1 cannot be torn, and the tearing process will stop midway, resulting in a defective product.

In contrast, in the bag-shaped container 1 of this embodiment, even if a similar misalignment occurs during the process of forming the cutting line 3, the guaranteed cutting line 5b located outside the end 3b of the cutting line 3 is detached from the tear strip 2a and formed on the base strip 2b, as shown in Figure 4(a).

Therefore, when the tear strip 2a is pulled up by the gripping portion 4 in this state, the force is concentrated at the stress concentration point P2 located on the inside of the tear strip 2a, but the force is eventually transmitted to the end of the guaranteed cut line 5b located near the stress concentration point P2, and this end becomes a new stress concentration point P3, causing a twist between the film 1a on the tear strip 2a and the film 1b on the base strip 2b.

Then, the twisting between the two restarts the tearing state, and the tear strip 2a can be pulled all the way up to complete the opening of the bag-like container 1.

The opposite side of the guaranteed cut line 5a is not used because the end 3a of the cut line 3 becomes the stress concentration point P1 on the outside of the tear strip 2a.

In this way, in the bag-shaped container 1 of this embodiment, the guaranteed cutting lines 5a, 5b are formed outside the ends 3a, 3b of the cutting line 3, so that even if a cutting line 3 occurs during the formation process, the opening operation using the tear strip 2a can be guaranteed as long as it is within half the difference between the distance L1 between the former and the distance L2 between the latter.
Other Embodiments

Another embodiment is shown in Figure 5. In the other embodiment shown in Figure 5(a), a pair of guaranteed cutting lines 15 (15a, 15b) are formed in a V-shape that opens toward the gripping portion 4.

With this structure, even if the positions of the cut line 3 and the guaranteed cut line 15 are significantly misaligned, the starting point that becomes the stress concentration point of the guaranteed cut line 15 is located outside the tear strip 2a, so the opening security effect can be improved.

In another embodiment shown in FIG. 5(b), a pair of guaranteed cut lines 25 (25a, 25b) are arranged to overlap the ends 3a, 3b of the cut line 3 in the longitudinal direction of the tear strip 2a. In this embodiment, the grip portion 14 cut out by the cut line 3 is formed so that the lower portion is longer than the upper portion based on the longitudinal direction of the tear strip 2a, making it easier for the user to lift it up.

With this structure, even if one of the ends 3a, 3b of the cutting line 3 gets into the tear strip 2a, the tearing operation can be continued from a closer position, with one of the safety cuts 25a, 25b acting as a re-stress concentration point.

Another embodiment shown in FIG. 5(c) has, in addition to the pair of guaranteed cut lines 5 (5a, 5b), a pair of second guaranteed cut lines 35 (35a, 35b) formed on the outer width side of the tear strip 2a.

With this structure, even if the cutting position of the punch die on the bag-shaped container 1 shifts significantly and one of the guaranteed cutting lines 5a, 5b enters the tear strip 2a, one of the second guaranteed cutting lines 35a, 35b will function as the starting point for the re-stress concentration point, further improving the opening security effect.

The first embodiment and other embodiments have been described above as specific bag-shaped containers of the present invention. However, for example, the guaranteed cut portion of the present invention may be a guaranteed cut point (point) rather than a guaranteed cut line (line segment). Also, if the deviation from the surface film occurs only in one direction, either vertically or horizontally, during the cutting line formation process, the guaranteed cut lines do not need to be a pair, and may be formed alone on only one side of the tear strip. Furthermore, the zipper tape 8 attached to the bag-shaped container 1 is optional, and the bag-shaped container 1 may be provided with only the tear tape 7.

1 Bag-shaped container 1A Surface film 1B Back film 1a Surface film 1b fixed to tear strip Surface film 2a fixed to base strip Tear strip 2b Base strip 3 Cutting lines 3a, 3b Ends of cutting lines 4 Grip portions 5, 5a, 5b Guaranteed cutting line (guaranteed cutting portion)
6 Airtight sheet 7 Tear tape 8 Zipper tape (zipper)
14 Grip part
15, 15a, 15b Guaranteed cutting line (guaranteed cutting part)
25, 25a, 25b Safety cut line (safety cut section)
35, 35a, 35b 2nd security cutting line (2nd security cutting part)
L1 Distance between a pair of cutting line ends L2 Distance between a pair of guaranteed cutting lines P1, P2, P3 Stress concentration point

Claims (4)

A bag-like container comprising a bag body formed by folding or overlapping a rectangular film to form a storage space, and a long tear strip disposed on the back side of the film, the tear strip having a gripping portion formed by cutting the film along a cutting line so as to have two ends on the outer sides of both edges of the tear strip in the width direction of the tear strip, and a user holds the gripping portion and lifts the tear strip to cut and open the bag body,
A bag-shaped container characterized in that a security cut portion is formed by cutting the film near the end of the cutting line, the security cut portion is formed on the outer side in the width direction of the tear strip, and the cut portion is covered with an airtight sheet on the back side of the film, thereby ensuring airtightness of the storage space. The bag-shaped container according to claim 1,
A bag-shaped container, characterized in that a pair of said compensation cut portions are formed so as to straddle said tear strip in the width direction. The bag-shaped container according to claim 1 or 2,
A bag-shaped container characterized in that a pair of second security cuts are formed in the vicinity of the pair of security cuts, and the distance between the second security cuts is greater than the distance between the two ends. The bag-shaped container according to claim 1 or 2,
The bag-shaped container further comprises a zipper that is fixed to the sealing sheet and the bag body, is arranged between the front and rear films in parallel with the tearable elongated material, and seals and can freely open an opening to the storage space formed by the tearable elongated material.

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