Packaging bags

Abstract

To provide a packaging bag that is opened by drawing an opening tape stuck on an inner surface side of a packaging film, and that can be opened wide without breaking of the opening tape in the middle of tear opening.SOLUTION: An opening tape 13 is stuck on an inner surface side of a top-side packaging film 11 of a packaging bag, a through hole 11α is provided at an opening start part of the opening tape 13, and the opening tape 13 is drawn from the exposed through hole 11α to tear the packaging film 11 along a length direction of the opening tape 13 so as to open the packaging bag. Then the top-side packaging film 11 is provided with a first weakening line 11β1 extending along its length direction and a second weakening line 11β2 reaching the first weakening line from a side edge part of the opening tape 13 outside the opening tape.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a packaging bag that is opened using tear tape. [Background technology]

[0002] BACKGROUND ART A packaging bag in which a tear tape is attached to the inner surface of a packaging film that constitutes the packaging bag is known (see Patent Document 1).

[0003] This packaging bag 200 is as shown in Figure 3. Note that Figure 3 is a plan view showing the entire packaging bag 200, and Figure 4 shows an explanatory cross-sectional view of a main part for explaining the main part. Figure 4(a) is an explanatory cross-sectional view of a main part taken along line XX in Figure 3, and Figure 4(b) is an explanatory cross-sectional view of a main part taken along line YY in Figure 3. Correspondingly, Figure 5 shows an explanatory cross-sectional view of a main part for explaining the main part when opening. Figure 5(a) is an explanatory cross-sectional view of a main part taken along line XX in Figure 3 when opening, and Figure 5(b) is an explanatory cross-sectional view of a main part taken along line YY in Figure 3 when opening.

[0004] This packaging bag 200 is formed by overlapping a front packaging film 21 and a back packaging film 22 and sealing them together at their peripheries. However, the back packaging film 22 is not shown in Fig. 3 because it is hidden behind the front packaging film 21. Also, in Fig. 3, a, b, c, and d each indicate a peripheral seal line, with "a" indicating the left seal line, "b" the right seal line, "c" the top seal line, and "d" the bottom seal line. A wide seal e (hereinafter referred to as "opening start seal") is provided at the corner where the left seal line a and the top seal line c intersect.

[0005] A plastic zipper 24 is attached to the inner surface of the front and back packaging films 21, 22. The plastic zipper 24 is composed of a concave occlusal tape 242 and a convex occlusal tape 241, and these two tapes 241, 242 are attached to the front packaging film 21 in an interlocking state. In this example, the convex occlusal tape 241 is attached to the inner surface of the front packaging film 21 in contact with it.

[0006] As shown in FIG. 4(b), the concave occlusal tape 242 extends to the seal e for opening start, while the convex occlusal tape 241 does not extend to the tear tape 23.

[0007] Next, of the front and back packaging films 21, 22, a tear-open tape 23 is attached to the inner surface of the front packaging film 21. This tear-open tape 23 passes through the inside of the opening start seal portion e and extends in the left-right direction of the illustrated packaging bag 200 from the left seal line a to the right seal line b.

[0008] For this reason, at the seal portion e for the opening start portion, as can be seen from Figure 4(a), the opening tape 23 is attached to the inner side of the front packaging film 21, and the concave occlusal tape 242 is attached to the opening tape 23 so that it can be easily peeled off.

[0009] The seal portion e for opening start portion is provided with a slit or through hole 20a that penetrates the seal portion e for opening start portion. That is, the slit or through hole 20a penetrates all of the front packaging film 21, the tear tape 23, the concave occlusion tape 242, and the back packaging film 22. As shown in FIG. 3, the slit or through hole 20a is formed by cutting the tear tape 23 and surrounding the end of the cut tear tape 23, and the area thus surrounded is the opening start portion 201. Since the through hole 20a has a shape that surrounds the opening start portion 201, the opening tape 23 can be pulled from the opening start portion 201 and easily drawn out to the outside of the packaging bag 200.

[0010] Furthermore, a slit or hole 20b is provided inside the opening start seal portion e, closer to the tearing direction than the slit or through-hole 20a. The slit or hole 20b penetrates the recessed occlusal tape 242 and the back packaging film 22, but is provided to a depth that does not penetrate the tear tape 23.

[0011] As is clear from the above description, the packaging bag 200 is opened and used as follows: That is, by inserting a finger into the slit or through-hole 20a, and pulling the area surrounded by the slit or through-hole 20a as the opening start portion 20A, the concave occlusal tape 242 and the back packaging film 22 are first cut at the slit or hole 20b, and then the tear tape 23 is peeled off from the concave occlusal tape 242 (see FIG. 5(a)). Then, by pulling further, the front packaging film 21 is torn along the longitudinal direction of the tear tape 23, and the bag can be opened.

[0012] In addition, this packaging bag 200 can be resealed using the zipper 24 after being opened. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-188196 Summary of the Invention [Problem to be solved by the invention]

[0014] As shown in FIG. 4, the packaging film 21 constituting the packaging bag 200 is usually configured by laminating a sealant layer 212 on the inner surface side of a base film 211.

[0015] A film having a single layer structure or a film having a multilayer structure may be used for the base film 211. In either case, if the base film 211 contains a stretched film in its layer structure and is relatively thick, the tear tape 23 may tear during pulling and tearing to open the package.

[0016] The reason for this is not clear, but it can be assumed that the stretching direction of the stretched film contained in the base film 211 crosses the pulling direction, causing the tear tape 23 to break without being able to withstand the force.

[0017] To provide a packaging bag that has been made under such a background and is opened by pulling an opening tape stuck to the inner surface of a packaging film, and that can be opened widely without the opening tape being torn off during tearing. [Means for solving the problem]

[0018] That is, the invention described in claim 1 is a packaging bag in which overlapping packaging films are sealed at the periphery, A packaging bag in which a tear tape is attached to the inner surface of one packaging film, a slit or through-hole is provided through the packaging film at the opening start portion of the tear tape, and the packaging film is torn along the longitudinal direction of the tear tape by pulling the tear tape from the slit or through-hole to open the bag, This packaging bag is characterized in that a weakened line is applied to the packaging film that is torn when opened, and this weakened line includes a first weakened line that is on the outside of the tearing tape and extends along its longitudinal direction, and a second weakened line that extends from the side edge of the tearing tape to the first weakened line.

[0019] The number of the first weakened lines is not limited to one, and multiple lines may be provided. In this case, it is desirable that the distance between the first weakened line closest to the tear tape and the tear tape is 2 mm or less. It is also desirable that the distance between the first weakened lines is 2 mm or less.

[0020] The second weakened line may be a line extending diagonally in the tearing direction of the packaging film. For example, the second weakened line may be a straight line extending 3 mm or less toward the outside of the tear tape when the second weakened line extends 4 mm in the tearing direction of the packaging film.

[0021] It is also possible to provide a plurality of second weakened lines. In this case, it is desirable that the distance between the second weakened lines measured along the longitudinal direction of the tear tape is 2 mm or less.

[0022] It is desirable that the first and second weakened lines are provided at a depth of 15% or more of the thickness of the packaging film.

[0023] Next, the packaging film may be constructed by laminating a base film and a sealant layer, and the base film may include a stretched film in its layer structure. In this case, it is desirable that the first and second weakened lines are lines provided in the base film. If the base film includes a resin layer having a polar group in its layer structure, the first and second weakened lines can be constructed by lines formed by absorption of laser light. [Effects of the Invention]

[0024] The present invention includes two types of weakened lines, namely, a first weakened line on the outside of the tear tape that extends along its longitudinal direction, and a second weakened line that extends from the side edge of the tear tape to the first weakened line. Therefore, even if the packaging film includes a stretched film or in addition uses a thick sealant film of 100 μm or more, the tear tape will not tear when pulled to tear it, and the tape can be opened widely as designed. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a plan view of a packaging bag according to an embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged plan view of the essential parts according to the embodiment of the present invention, for explaining the essential parts. [Figure 3] FIG. 3 is a plan view of a conventional packaging bag. [Figure 4] 4A and 4B show a conventional packaging bag, in which FIG. 4A is a cross-sectional view of a main part taken along line XX in FIG. 3, and FIG. 4B is a cross-sectional view of a main part taken along line YY in FIG. [Figure 5] 5A and 5B show a conventional packaging bag, in which FIG. 5A is an explanatory cross-sectional view of the essential part taken along line XX in FIG. 3 when opened, and FIG. 5B is an explanatory cross-sectional view of the essential part taken along line YY in FIG. 3 when opened. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a plan view of a packaging bag according to an embodiment of the present invention, and Fig. 2 is an enlarged plan view of a main part thereof for explaining the main part.

[0027] The main structure of this packaging bag 100 is the same as that of the above-mentioned packaging bag 200. That is, the packaging bag 100 is made by overlapping a front packaging film 11 and a back packaging film 12 (not shown) and sealing them together at their peripheries, and in the drawing, "a" indicates the left seal line, "b" indicates the right seal line, "c" indicates the top seal line, "d" indicates the bottom seal line, and "e" indicates the seal portion for starting opening.

[0028] A convex occlusal tape 141 is attached to the inner surface of the front packaging film 11, and a concave occlusal tape 142 is attached to the inner surface of the back packaging film 12. The convex occlusal tape 141 and the concave occlusal tape 142 are attached to each other. The concave occlusal tape 142 extends to the opening start seal e, while the convex occlusal tape 141 does not extend to the tear tape 13.

[0029] A tear tape 13 is attached to the inner surface of the front packaging film 11, and this tear tape 13 passes through the inside of the opening start seal portion e and extends in the left-right direction of the illustrated packaging bag 100 from the left seal line a to the right seal line b. The concave occlusal tapes 142 are attached together in such a way that they can be easily peeled off.

[0030] Furthermore, a slit or through-hole 10a is provided in this seal portion e for opening start portion, and as in the case of the conventional packaging bag 200, this slit or through-hole 10a penetrates through all of the front packaging film 11, tear tape 13, concave occlusion tape 142, and back packaging film 12, and the area surrounded by this slit or through-hole 10a forms an opening start portion 101. Furthermore, a slit or hole 10b is provided inside this seal portion e for opening start portion, on the tear direction side of the slit or through-hole 10a. The slit or hole 10b penetrates through the concave occlusion tape 142 and back packaging film 12, but is provided to a depth not penetrating the tear tape 13.

[0031] In this packaging bag 100, unlike the packaging bag 200 described above, two types of weakened lines 11α and 11β are provided in the front packaging film 11 to which the tear tape 13 is attached.

[0032] Of these two types of weakened lines 11α and 11β, the first weakened line 11α is located on the outside of the tear tape 13 and extends along its longitudinal direction. When the tear line that tears the front packaging film 11 during opening comes off the side edge of the tear tape 13, this first weakened line 11α guides the tear line to prevent the tear tape 13 from tearing. For this reason, it is desirable that the first weakened line 11α extend to the end where the tear is intended to occur.

[0033] Furthermore, one first weakened line 11α may be provided on each side of the tear tape 13, but it is preferable to provide multiple first weakened lines 11α on each side of the tear tape 13 so that the first weakened lines 11α are reliably positioned on the outside of the tear tape 13 even if the positions of the first weakened lines 11α are shifted during processing. In the packaging bag 100 according to this embodiment, two first weakened lines 11α are provided on each side of the tear tape 13, but this is not limited to this, and three or more first weakened lines 11α may be provided on each side of the tear tape 13. In any case, it is preferable that the distance z1 between the tear tape 13 and the first weakened line 11α1 closest to the tear tape 13 is 2 mm or less. In this example, the width z0 of the tear tape 13 is 2 mm, and the distance z1 is 1 mm. When a plurality of first weakened lines 11α are provided, the distance z2 between these first weakened lines 11α is preferably 2 mm or less, and is also preferably equal to the distance z1. In this packaging bag 100, the distance z2 between the first weakened lines 11α is 1 mm, the same as the distance z1.

[0034] Next, the second weakened line 11β guides the tear line to the first weakened line 11α when the tear line separates from the side edge of the tear tape 13. For this reason, the second weakened line 11β extends from the side edge of the tear tape 13 to the first weakened line 11α. For this reason, as shown in the figure, the second weakened line 11β is configured as a line extending diagonally toward the tear direction of the front packaging film 11. Furthermore, in order to smoothly guide the tear line to the first weakened line 11α, it is desirable that the second weakened line 11β be a straight line that extends 3 mm or less toward the outside of the tear tape 13 when it extends 4 mm in the tear direction of the front packaging film 11. Note that the second weakened line 11β is not limited to a straight line and may be a curved line. However, even if it is a curved line, it is desirable that the second weakened line 11β extend 3 mm or less toward the outside of the tear tape 13 when it extends 4 mm in the tear direction of the front packaging film 11.

[0035] In the packaging bag 100 according to this embodiment, the distance y1 in the tearing direction from the side edge of the tear tape 13 to the second-nearest first weakened line 11α2 is 4 mm. As described above, the distance z1 between the tear tape 13 and the first weakened line 11α1 closest to the tear tape 13 is 1 mm, and the distance z2 between the first weakened lines 11α is also 1 mm, so the distance from the side edge of the tear tape 13 to the second-nearest first weakened line 11α2 is z1 + z2 = 2 mm. That is, in this packaging bag 100, the second weakened line 11β is configured as a straight line that advances 2 mm toward the outside of the tear tape 13 when advancing 4 mm in the tearing direction of the front packaging film 11.

[0036] If a plurality of first weakened lines 11α are provided, it is desirable that second weakened line 11β reach all of the plurality of first weakened lines 11α. It is also desirable that the end point of second weakened line 11β be located on the first weakened line 11α among the plurality of first weakened lines 11α that is located at a position farthest from tear tape 13. This is to ensure that the tear line induced by second weakened line 11β is connected to first weakened line 11α.

[0037] Furthermore, although one second weakened line 11β may be provided on each side of the tear tape 13, it is preferable to provide multiple second weakened lines 11β to ensure that the tear line that tears the front packaging film 11 is guided to the first weakened line 11α. As shown in the figure, three second weakened lines 11β are provided in this packaging bag 100. When multiple second weakened lines 11β are provided in this manner, it is preferable that the distance y2 between the second weakened lines 11β is 2 mm or less when measured along the longitudinal direction of the tear tape. In this packaging bag 100, the distance y2 is 1 mm.

[0038] The front packaging film 11 may be any film, but its thickness is preferably 30 μm or more. In this case, both the first weakened line 11α and the second weakened line 11β are preferably formed at a depth of 15% or more of the thickness of the packaging film. In this case, the tear line that tears the front packaging film 11 can be reliably guided, preventing the tear tape 13 from being torn. The advantages of the present invention are best realized when the front packaging film 11 is made of a relatively thick film, such as a film with a thickness of 130 μm or more.

[0039] The advantages of the present invention can also be preferably utilized when the outer packaging film 11 is constructed by laminating a base film and a sealant layer, and the base film contains a stretched film in its layer structure. The base film may have a single-layer structure or a multi-layer structure. Examples of stretched films with a single-layer structure include stretched polypropylene film, stretched polyester film, and stretched polyamide film. In addition, in a multi-layer structure, the layers The base film containing a stretched film in its construction can be constructed by laminating two or more films selected from the group consisting of stretched polypropylene film, stretched polyester film, and stretched polyamide film.

[0040] On the other hand, the sealant layer may be a conventional sealant film, which is generally a non-oriented film made of polyolefin such as low-density polyethylene, medium-density polyethylene, linear low-density polyethylene, or polypropylene.

[0041] It is known that carbon dioxide laser light is absorbed by polar groups such as ester groups and amide groups, but not by nonpolar groups. Therefore, a film containing a resin layer having polar groups in its layer structure is used as the base film, and a conventional nonpolar polyolefin film is used as the sealant layer. These base film and sealant layer are laminated together to form the front packaging film 11. Then, carbon dioxide laser light is irradiated onto the front packaging film 11. The light is absorbed by the polar film in the base film, forming both the first weakened line 11α and the second weakened line 11β. Since the nonpolar sealant layer does not absorb the light, it is not affected by the laser light. Examples of resin films having polar groups include polyester film and polyamide film.

[0042] According to the inventor's investigations, a two-layer base film was formed by laminating a stretched polyester film (thickness 12 μm) and a stretched polyamide film (thickness 15 μm), and a sealant film (thickness 100 μm) made of linear low-density polyethylene was laminated on the stretched polyamide film side to form the front packaging film 11 (thickness 130 μm).A carbon dioxide laser beam was then irradiated to form both a first weakened line 11α and a second weakened line 11β with a depth of 20.3% of the thickness of the front packaging film 11.When the tear tape 13 was pulled from the opening start portion 101 to tear and open the front packaging film 11, the tear tape 13 was not torn and the film could be opened widely as designed.

[0043] Furthermore, when a two-layer base film was formed by laminating a stretched polyester film (thickness 12 μm) and a stretched polyamide film (thickness 15 μm), and a sealant film (thickness 120 μm) made of linear low-density polyethylene was laminated on the stretched polyamide film side to form the front packaging film 11 (thickness 150 μm), and then a carbon dioxide laser beam was irradiated to form both a first weakened line 11α and a second weakened line 11β with a depth of 18.0% of the thickness of the front packaging film 11, it was confirmed that the tear tape 13 could be opened widely as designed without tearing. [Explanation of symbols]

[0044] 100: Packaging bag 10a: Penetrating slit or through hole 101: Opening start portion 11: Outer packaging film 11α: First weakened line 11β: Second weakened line 13: Opening tape 14: Plastic zipper 141: Convex articulating tape 142: Concave articulating tape y1: the distance that the second weakened line 11β travels in the tearing direction from the side edge of the tear tape 13 to the first weakened line 11α, which is located second from the side edge y2: The distance between the second weakened lines 11β when measured along the longitudinal direction of the tear tape 13 z0: Width of tear tape 13 z1: Distance between the first weakened line 11α1 closest to the tear tape 13 and the tear tape 13 z2: distance between the first weakened lines 11α a: Left side seal line b: Right side seal line

Claims

1. A packaging bag in which overlapping packaging films are sealed at the periphery, A packaging bag in which a tear tape is attached to the inner surface of one packaging film, a slit or through-hole is provided through the packaging film at the opening start portion of the tear tape, and the packaging film is torn along the longitudinal direction of the tear tape by pulling the tear tape from the slit or through-hole to open the bag, A packaging bag characterized in that a weakened line is provided in the packaging film that is torn when opened, and this weakened line includes a first weakened line that is on the outside of the tearing tape and extends along its longitudinal direction, and a second weakened line that extends from the side edge of the tearing tape to the first weakened line.

2. 2. The packaging bag according to claim 1, wherein a plurality of the first weakened lines are provided.

3. 3. The packaging bag according to claim 2, wherein the distance between the tear tape and the first weakened line closest to the tear tape among the plurality of first weakened lines is 2 mm or less.

4. 4. The packaging bag according to claim 2, wherein the distance between the first weakened lines is 2 mm or less.

5. 5. The packaging bag according to claim 1, wherein the second weakened line is a line extending obliquely toward the tearing direction of the packaging film.

6. The packaging bag according to claim 5, characterized in that the second weakened line is a straight line that extends 3 mm or less toward the outside of the tear tape when extending 4 mm in the tearing direction of the packaging film.

7. 7. The packaging bag according to claim 1, wherein a plurality of the second weakened lines are provided.

8. 8. The packaging bag according to claim 7, wherein the distance between the second weakened lines is 2 mm or less when measured along the longitudinal direction of the tear tape.

9. A packaging bag according to any one of claims 1 to 8, characterized in that the thickness of the packaging film is 30 μm or more, and the first weakened line and the second weakened line are lines provided at a depth of 15% or more of the thickness of the packaging film.

10. The packaging bag according to any one of claims 1 to 9, characterized in that the packaging film is constructed by laminating a base film and a sealant layer, and the base film includes a stretched film in its layer structure.

11. 11. The packaging bag according to claim 10, wherein the first and second weakened lines are lines provided in the base film.

12. The packaging bag according to claim 11, characterized in that the base film includes a resin layer having a polar group in its layer structure, and the first weakened line and the second weakened line are lines formed by absorbing laser light.

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