Patent Application
20230399146
The invention relates to a container provided with a zipper tape, a method of manufacturing a container provided with a zipper tape, and a device configured to manufacture a container provided with a zipper tape.
A bag provided with a zipper tape is widely used for packaging various articles such as medicines and foods. One of advantages of such a bag provided with a zipper tape is easy openability and resealablility. A user is able to disengage the zipper tape and open the bag by pulling both surfaces of the bag to which the zipper tape is bonded in such a manner as to separate the surfaces from each other. The user is also able to engage the zipper tape and reseal the bag by pressing both the surfaces of the bag in such a manner as to bring the surfaces close to each other.
Upon opening the above-described bag provided with a zipper tape, each of both surfaces of the bag is generally pinched with fingers and pulled in a direction perpendicular to a longitudinal direction of the zipper tape. In this case, both hands of the user are necessary for opening. In contrast, Patent Literature 1 discloses a technique that allows a user to open a bag by sliding alternately each of both surfaces of the bag along a longitudinal direction of a zipper tape. In this case, it is possible to disengage the zipper tape and open the bag by performing the following operation. The user pinches and twists each of both surfaces of the bag with fingers of one hand, specifically, a thumb and an index finger of one hand.
The technique of Patent Literature 1 describes the opening operation for disengaging the zipper tape by bending only one surface of the bag on both sides of a part where the user pinches. However, a situation in which such an opening operation is easily performable is limited to a case where rigidity of the zipper tape is relatively low and the zipper tape is soft. Accordingly, in a case where the zipper tape includes a rigid material in order to resist internal pressure of the bag or to prevent unintended opening caused by external force by strengthening the engagement, it is not easy to bend the zipper tape. It is thus difficult to employ the technique of Patent Literature 1.
In view of the above, a technique disclosed in Patent Literature 2 has been proposed. Patent Literature 2 discloses a bag provided with a zipper tape, including: a bag body having at least one pair of facing surfaces; and an elongated zipper tape whose cross sectional profile includes at least one pair of base strips each bonded to corresponding one of the pair of facing surfaces, and at least one pair of engagement portions that are protruded from the respective base strips and mutually engageable, in which the zipper tape is provided with hinges at two positions in a longitudinal direction.
According to a configuration described in Patent Literature 2, it is possible to easily open a bag by sliding each of both sides of the bag in a longitudinal direction of a zipper tape, irrespective of rigidity of the zipper tape. However, for example, in a case of preventing unintended opening caused by external force, engagement of the zipper tape becomes relatively weak in a hinge portion. This can lead to a situation in which a function of preventing the unintended opening is not sufficiently exhibited.
It is therefore an object of the invention to provide a container provided with a zipper tape, a method of manufacturing a container provided with a zipper tape, and a device of manufacturing a container provided with a zipper tape that make it possible to prevent engagement strength in a hinge portion from becoming relatively weak, in which the container provided with a zipper tape is able to be opened easily by causing each of both surfaces of the container to be slid in a longitudinal direction of a zipper tape.
[10] According to another aspect of the invention, a method of manufacturing a container provided with a zipper tape includes: feeding a zipper tape including a first base strip, a second base strip, a first engagement portion, and a second engagement portion, the first engagement portion and the second engagement portion respectively protruding from the first base strip and the second base strip and being engageable with each other; bonding the first base strip and the second base strip respectively to a first area and a second area of a film that are opposed to each other; forming a container body by cutting the film; and forming a hinge at at least one position that satisfies m/n<0.25, where “n” represents a length of an opening portion of the container body, and “m” represents a distance from the hinge to an inner end portion of the opening portion in a longitudinal direction of the zipper tape.
In the exemplary embodiment, the hinge is provided at at least one position that satisfies m/n<0.25, where “n” represents the length of the opening portion of the container body, and “m” represents the distance from the hinge to the inner end portion of the opening portion in the longitudinal direction of the zipper tape. The base strips of the zipper tape are bonded to each other and fixed in that state in the bonding region. Thus, the engagement strength of the engagement portions is relatively higher in a part close to the bonding region in the longitudinal direction of the zipper tape than in the other part. Providing the hinge at the above-described position makes it possible to compensate for a decrease in the engagement strength due to change in shapes of the engagement portions at the hinge, because the engagement strength in each of the respective sections on both sides of the hinge is relatively high. It is therefore possible to prevent the engagement strength in the hinge from being relatively weak in the bag provided with a zipper tape.
The following describes preferred exemplary embodiments of the invention in detail with reference to the accompanying drawings. It is to be noted that, in this description and the accompanying drawings, components that have substantially the same functional configuration are indicated by the same reference signs, and thus redundant description thereof is omitted.
As illustrated in
The film 110 includes, for example, a single-layer or multi-layer thermoplastic resin. Specifically, a thermoplastic resin may be low density polyethylene (LDPE), linear low density polyethylene (LLDPE), or polypropylene (PP). PP may be a polypropylene homopolymer (HPP), a polypropylene random copolymer (RPP), or a polypropylene block copolymer (BPP). In a case where the film 110 includes a multi-layered film, biaxially oriented polypropylene (OPP), biaxially oriented polyethylene terephthalate (OPET), or biaxially oriented nylon (ONy) may be used for a surface base. These are each not limited to a resin derived from a fossil fuel, and may each be an environmentally friendly bio-plastic or a mixture of the resin derived from the fossil fuel and the bio-plastic. Examples of the bio-plastic preferably include bio-polyethylene. Further, the film 110 may include a layer of a metal material such as aluminum, or a layer of an inorganic material. For example, the film 110 may include a monomaterial resin composition which includes polyethylene as a main component, as with the zipper tape 120. This enables achievement of an environmentally friendly configuration having excellent recyclability.
The film 110 has a thickness of, for example, 20 μm or more, preferably 35 μm or more, more preferably 50 μm or more. Further, the film 110 has a thickness of, for example, 300 μm or less, preferably 200 μm or less, more preferably 180 μm or less.
In the exemplary embodiment, the first area 111A and the second area 111B may be formed by stacking two films 110, and bonding the two films 110 to each other at a bottom seal 112 and side seals 113. However, in another exemplary embodiment, for example, one film 110 may be folded at a part corresponding to the bottom seal 112 and bonded at the side seals 113. The side seal 113 is a bonding region which is provided at each of both ends in a longitudinal direction of the zipper tape 120, and in which the first area 111A, the base strips 121A and 121B of the zipper tape 120, and the second area 111B are stacked in this order and bonded to each other.
Further, a part in which the film is folded inward, that is, a so-called gusset, may be provided in a part corresponding to the bottom seal 112 or the side seal 113. In this case, the gusset may include the same film as that of the first area 111A or the second area 111B, or may include another film that is different therefrom. The bag provided with a zipper tape 100 may also be a stand up pouch which is able to be placed upright by the gusset being provided at a bottom of the bag provided with a zipper tape 100.
In the exemplary embodiment, the bag body has a mouth by being provided with the bottom seal 112 and the side seal 113 but not being provided with a top seal. However, in another exemplary embodiment, the top seal may be provided in addition to the bottom seal and the side seal, and the mouth may be provided afterward in the bag body by cutting between the top seal and the zipper tape.
In still another exemplary embodiment, the bag provided with a zipper tape may be provided in a state in which the bottom seal on an opposite side from the zipper tape is not provided. In this case, the bottom seal is formed after the bag is filled with contents. In addition, it is possible to apply the invention to a bag provided with a zipper tape having various known configurations.
The zipper tape 120 is formed, for example, by extrusion molding of a polyolefin-based resin. More specifically, the zipper tape 120 may include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), or polypropylene (PP). PP may be a polypropylene homopolymer (HPP), a polypropylene random copolymer (RPP), or a polypropylene block copolymer (BPP). These are each not limited to a resin derived from a fossil fuel, and may each be an environmentally friendly bio-plastic or a mixture of the resin derived from the fossil fuel and the bio-plastic. Examples of the bio-plastic preferably include bio-polyethylene. To the material of the zipper tape 120, a known additive such as a stabilizer, an antioxidant, a lubricant, an antistatic agent, or a colorant may be added as necessary.
The zipper tape 120 may include a monomaterial resin composition which includes polyethylene as a main component. In this case, the zipper tape 120 as a whole includes the resin composition which includes polyethylene as the main component. Here, the main component is a component that occupies a predetermined percentage or more of the resin composition, and a content of the component is usually 50 mass % or more, preferably 70 mass % or more, more preferably 90 mass % or more, still more preferably 95 mass % or more, still further more preferably 98 mass % or more, and yet still further more preferably 100%. However, even in the case where the content of the main component is 100%, mixing of an additive and impurities is acceptable. The main component is confirmable by, for example, an IR method. The zipper tape 120 including the monomaterial resin composition which includes polyethylene as the main component enables an environmentally friendly configuration having excellent recyclability. Further, using bio-polyethylene as polyethylene makes it possible to achieve an environmentally friendly configuration which is further excellent in recyclability.
It is to be noted that, in the zipper tape 120, the shapes of the engagement portions 122A and 122B are not limited to the illustrated example, and it is possible to employ various shapes of engagement portions of known zippers having a combination of a claw shape, a hook shape, a knob shape, or the like. In the illustrated example, the engagement portion 122A has a male shape and the engagement portion 122B has a female shape; however, the engagement portions 122A and 122B may be the other way around. In addition, although a pair of engagement portions is disposed in the illustrated example, a plurality of pairs of engagement portions may be disposed.
In the exemplary embodiment, the engagement portions 122A and 122B each having an irregular cross sectional profile in the zipper tape 120 are thinned, whereby the thin portions 131A and 131B each serve as a hinge of the zipper tape 120. Herein, the hinge means a point at which a deflection angle of the zipper tape 120 becomes discontinuous due to no or relatively weakened bending moment being transmitted to the longitudinal direction of the zipper tape 120. Accordingly, the zipper tape 120 is easily bendable at the hinge.
As illustrated in (A) of
Here, the thin portions 131A and 131B are each provided at a position that satisfies m/n<0.25, where “n” represents a length of the opening portion of the bag body, and “m” represents a distance to an inner end portion of the opening portion (one of both ends of a section of the length n) in the longitudinal direction of the zipper tape. The value of m/n is preferably 0.22 or less, more preferably 0.20 or less, still more preferably 0.16 or less, and yet still more preferably 0.12 or less. A lower limit of m/n may be 0, but is preferably 0.01 or more, more preferably 0.03 or more, and still more preferably 0.05 or more. Setting the value of m/n within this range makes it possible to achieve both openability and a function of preventing unintended opening with higher accuracy. Here, the length n of the opening portion of the bag body is, for example, 30 mm or more, preferably 50 mm or more, and more preferably 70 mm or more. Further, the length n of the opening portion of the bag body is, for example, 500 mm or less, preferably 400 mm or less, and more preferably 350 mm or less.
The thin portions 131A and 131B may each be provided at a position where the distance m to the side seal 113 that is the bonding region is 20 mm or less in the longitudinal direction of the zipper tape 120. Here, the distance m is a distance from an end edge of the side seal 113 on a side closer to a corresponding one of the thin portions 131A and 131B to an end edge of the corresponding one of the thin portions 131A and 131B on an opposite side from the relevant side seal 113. In other words, a region in which each of the thin portions 131A and 131B is to be provided is within a range of the distance m from the end edge of the side seal 113 on the closer side. The distance m is preferably 18 mm or less, more preferably 15 mm or less, and still more preferably 12 mm or less. Further, the distance m may be 0 mm; however, from the viewpoint of openability, the distance m is preferably 3 mm or more, more preferably 5 mm or more, and still more preferably 7 mm or more. The values of the distances m may be the same as or different from each other.
As illustrated in (B) of
Further, in order to facilitate the above-described opening operation, an antislip structure 140 may be provided as illustrated in
In the exemplary embodiment, the thin portions 131A and 131B are each provided at the position that satisfies m/n<0.25, where “n” represents the length of the opening portion of the bag body, and “m” represents the distance to the inner end portion of the opening portion in the longitudinal direction of the zipper tape. In the side seal 113 that serves as the inner end portion of the opening portion, the base strips 121A and 121B of the zipper tape 120 are bonded to each other and fixed in that state. Thus, engagement strength of the engagement portions 122 is relatively higher in a part close to the side seal 113 in the longitudinal direction of the zipper tape 120 than in the other part. Providing the thin portions 131A and 131B at the above-described positions makes it possible to compensate for a decrease in the engagement strength due to change in shapes of the engagement portions 122 at the thin portions 131A and 131B, because the engagement strength in each of the respective sections on both sides of the thin portions 131A and 131B is relatively high. It is therefore possible in the exemplary embodiment to prevent the engagement strength in the thin portions 131A and 131B from being relatively weak in the bag provided with a zipper tape 100.
Specifically, for example, if the engagement strength of the zipper tape 120 in a section that includes neither the thin portion 131A nor the thin portion 131B is 26 N/50 mm or more, it is possible to prevent the unintended opening of the bag provided with a zipper tape 100 starting from the thin portions 131A and 131B. The engagement strength of the zipper tape 120 in the section that includes neither the thin portion 131A nor the thin portion 131B is preferably 30 N/50 mm or more, more preferably 40 N/50 mm or more. The engagement strength is measurable, for example, using a digital force gauge (available from Imada Corporation) as follows. First, the base strips 121A and 121B are each held at a part 2 mm away from the engagement portion of the zipper tape that is cut into a length of 50 mm in the longitudinal direction. Thereafter, while the base strip 121A is fixed, the base strip 121B is pulled up to measure strength until the engagement portions 122 are disengaged. A measurement result of a maximum load is given as the engagement strength. If the length in the longitudinal direction is less than 50 mm, and the length is X mm, it is possible to convert the engagement strength into N/50 mm by multiplying the measurement result N/X mm by 50/X.
In the exemplary embodiment, the cuts 132A and 132B each serve as the hinge of the zipper tape 120. The cuts 132A and 132B reach the engagement portions 122A and 122B each having the irregular cross sectional profile in the zipper tape 120. As already described above in the first exemplary embodiment, the zipper tape 120 is easily bendable at the hinge. As with the first exemplary embodiment, the cuts 132A and 132B are provided at respective positions close to the both ends in the longitudinal direction of the zipper tape 120. Specifically, the cuts 132A and 132B are each provided at the position where the distance m to the side seal 113 that is the bonding region is 20 mm or less in the longitudinal direction of the zipper tape 120. The distance m is defined similarly to that in the first exemplary embodiment, and a region in which each of the cuts 132A and 132B is to be provided is within a range of the distance m from the end edge of the side seal 113 on the closer side.
As with the first exemplary embodiment, also in the above-described second exemplary embodiment of the invention, the cuts 132A and 1328 with which the zipper tape 120 is provided each function as the hinge, which makes it easier to bend any one of the engagement portion 122A or 1228 of the zipper tape 120 at the cuts 132A and 132B, even in a case where the zipper tape 120 includes a material having relatively high rigidity. Further, also in the exemplary embodiment, the cuts 132A and 1328 are each provided at the position that satisfies m/n<0.25, where “n” represents the length of the opening portion of the bag body, and “m” represents the distance to the inner end portion of the opening portion in the longitudinal direction of the zipper tape. This makes it possible to compensate for the decrease in the engagement strength caused by lack of the engagement portions 122 at the cuts 132A and 1328. It is therefore possible in the exemplary embodiment to prevent the engagement strength in the cuts 132A and 1328 from being relatively weak in the bag provided with a zipper tape 200.
In the exemplary embodiment, the punched holes 133A and 133B each serve as the hinge of the zipper tape 120. The punched holes 133A and 133B penetrate through the engagement portions 122A and 122B each having the irregular cross sectional profile in the zipper tape 120. As already described above in the first exemplary embodiment, the zipper tape 120 is easily bendable at the hinge. As with the first exemplary embodiment, the punched holes 133A and 133B are provided at respective positions close to the both ends in the longitudinal direction of the zipper tape 120. Specifically, the punched holes 133A and 133B are each provided at the position where the distance m to the side seal 113 that is the bonding region is 20 mm or less in the longitudinal direction of the zipper tape 120. The distance m is defined similarly to that in the first exemplary embodiment, and a region in which each of the punched holes 133A and 133B is to be provided is within a range of the distance m from the end edge of the side seal 113 on the closer side.
As with the first exemplary embodiment, also in the above-described third exemplary embodiment of the invention, the punched holes 133A and 133B with which the zipper tape 120 is provided each serve as the hinge, which makes it easier to bend any one of the engagement portion 122A or 122B of the zipper tape 120 at the punched holes 133A and 133B, even in a case where the zipper tape 120 includes a material having relatively high rigidity. Further, also in the exemplary embodiment, the punched holes 133A and 133B are each provided at the position that satisfies m/n<0.25, where “n” represents the length of the opening portion of the bag body, and “m” represents the distance to the inner end portion of the opening portion in the longitudinal direction of the zipper tape. This makes it possible to compensate for the decrease in the engagement strength caused by lack of the engagement portions 122 at the punched holes 133A and 133B. It is therefore possible in the exemplary embodiment to prevent the engagement strength in the punched holes 133A and 1338 from being relatively weak in the bag provided with a zipper tape 300.
In the above exemplary embodiments, the examples have been described in which the hinge is provided at each of two positions that satisfy m/n<0.25 at the both ends of the zipper tape, where “n” represents the length of the opening portion of the bag body, and “m” represents the distance from the hinge to the inner end portion of the opening portion in the longitudinal direction of the zipper tape. However, the hinge may be provided only at one position at one of the both ends of the zipper tape. In the above exemplary embodiments, the examples have been described in which a container body has a bag shape. However, a container including the zipper tape and a container body other than the bag-shaped container body may be provided.
Example of Zipper Tape that Prevents Unintended Opening
Method of Manufacturing Bag Provided with Zipper Tape
In the film 110 to which the zipper tape 120 has been bonded, a seal bar 606 forms the bottom seal 112 between the first area 111A and the second area 111B, and a seal bar 607 similarly forms the side seal 113. A cutting blade 608 cuts the film 110 in a longitudinal direction along the bottom seal 112, and a cutting blade 609 cuts the film 110 in a width direction along the bottom seal 112. Through those processes of forming the film 110 into the bag body, the bag provided with a zipper tape 100 is manufactured. This applies similarly to the bags provided with zipper tapes 200 and 300 according to the second and third exemplary embodiments.
Here,
In the illustrated example, the pressing members 610A and 610B are disposed across the side seal 113 prior to the film 110 being cut along the side seal 113. This makes it possible to effectively form the thin portions 131A and 131B in a case where the thin portions 131A and 131B are each to be provided at a position close to the side seal 113, specifically, in a case where the thin portions 131A and 131B are each to be formed at the position that satisfies m/n<0.25, where “n” represents the length of the opening portion of the bag body, and “m” represents the distance to the inner end portion of the opening portion in the longitudinal direction of the zipper tape. For example, it is possible to use the same pressing members 610A and 610B to form the thin portions 131A and 131B even in a case where the bag provided with a zipper tape 100 is changed in width. In other words, in the exemplary embodiment, forming the hinges such as the thin portions 131A and 131B closer to the end portions allows a distance from one of the end portions of the bag body to the corresponding one of the hinges to be constant if the width of the bag provided with a zipper tape 100 does not change greatly. This makes it possible to form the hinges with the same jig regardless of the width of the bag. In another example, the hinges may be formed by different jigs depending on the width of the bag provided with a zipper tape 100, or the hinges on the both sides may be formed by respective jigs that are different from each other.
The thin portions 131A and 131B are formed by the protrusions 611 in the above-described example. Similarly, it is possible to form the cuts 132A and 132B of the bag provided with a zipper tape 200 according to the second exemplary embodiment by providing cut blades in place of the protrusions 611. Further, it is possible to form the punched holes 133A and 133B of the bag provided with a zipper tape 300 according to the third exemplary embodiment by providing punches in place of protrusions 611 and providing die holes having shapes corresponding to the punches at respective positions that are opposed to the punches. In the illustrated example, the thin portion 131A is formed by being pressed from the first area 111A and the thin portion 131B is formed by being pressed from the second area 111B; however, both of the thin portions 131A and 131B may be formed by being pressed from the first area 111A, the second area 111B, or both.
In the above-described examples, the hinges are formed in the zipper tape 120 in the position of the arrow P4 illustrated in
It is to be noted that, although the bag provided with a zipper tape is manufactured by the three-side-seal bag-making machine in the above-described examples, it is not limited to the three-side-seal bag-making machine. In various other bag-making machines, the device as described with reference to
In the example illustrated in
In contrast, in the example illustrated in
The configuration illustrated in
Preferred exemplary embodiments of the invention have been described above in detail with reference to the accompanying drawings, but the invention is not limited to such exemplary embodiments. It is apparent that a skilled person in the art of the invention can arrive at various alterations and modifications within the scope of the technical idea recited in the appended claims, and it is understood that such alterations and modifications naturally fall within the technical scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-188086 | Nov 2020 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/041443 | 11/11/2021 | WO |
