Zippers, opening structures and packaging boxes

Abstract

To provide a zipper capable of suppressing unintended breakage and improving aesthetic properties after breakage.SOLUTION: There is provided a zipper 20 including a cut group 21, the cut group 21 being formed such that a first cut 22 and a pair of second cuts 23 are cut into a paper material with an interval in an opening direction. The first cut 22 protrudes in one direction in a derailment direction and is formed in a mountain shape that is symmetrical with respect to a first center line CL1, and the pair of second cuts 23 are arranged on both sides of the first cut 22 in the opening direction, and are symmetrical about the first cut 22, each protruding in one direction in the derailment direction and formed in a mountain shape that is asymmetric with respect to a second center line CL2, and both ends 25 of the first cut 22 and inner ends 26 of the pair of second cuts 23 are formed at positions separated in the opening direction, and both ends 25 of the first cut 22, the inner ends 26 of the pair of second cuts 23, and outer ends 27 of the pair of second cuts 23 are formed at positions shifted from each other in the derailment direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a zipper, an opening structure and a packaging box that are comprised of multiple cuts in a paper material. [Background technology]

[0002] A paper tear strip with two parallel rows of cuts is known (Patent Document 1). Each row of cuts is formed by intermittently forming cuts in a zigzag pattern with a short side portion at one end of the long side and a jumping part at the other end of the long side. In adjacent cuts, the tip of the short side portion is located inside the tip of the jumping part. Specifically, the adjacent short side portions and the jumping parts are formed parallel to each other, and parts of them face each other with a small seam in between. This allows the tear strip to be torn from either one or the other of the opening direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-104398 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned cut row, the adjacent short side portions and the jumping portions face each other so as to overlap at close positions, and the joints are very narrow, so there is a risk of the material tearing due to impact during transportation, etc. In addition, since the cuts constituting the cut row are formed in a zigzag pattern, the traces of the break (fracture surface) are also zigzag, which causes a problem of poor aesthetics after breakage.

[0005] In consideration of the above circumstances, the present invention provides a zipper, an opening structure, and a packaging box that can suppress unintentional breakage while improving the aesthetic appearance after breakage. [Means for solving the problem]

[0006] The present invention relates to a zipper comprising at least one group of cuts, in which a first cut and a pair of second cuts are cut into a paper material at intervals in the opening direction to form a cut group, wherein the first cut protrudes in one direction in a derailment direction perpendicular to the opening direction on a plane, and is formed in a mountain shape that is linearly symmetrical about a first center line extending along the derailment direction; the pair of second cuts are disposed on both sides of the opening direction across the first cut, and are shaped to be linearly symmetrical about the first cut, and each protrudes in one direction in the derailment direction and is formed in a mountain shape that is asymmetrical about a second center line extending along the derailment direction; both ends of the first cut and inner ends of the pair of second cuts adjacent to both ends of the first cut are formed at positions spaced apart in the opening direction; and both ends of the first cut, the inner ends of the pair of second cuts, and outer ends of the pair of second cuts that are both ends in the opening direction are formed at positions shifted from each other in the derailment direction.

[0007] In this case, the inner ends of the pair of second cuts may be formed in a position shifted in one direction of the derailment direction from the both ends of the first cuts and shifted in the other direction of the derailment direction from the top of the first cuts, and the outer ends of the pair of second cuts may be formed in a position shifted in the other direction of the derailment direction from the both ends of the first cuts.

[0008] In this case, the apex of the first cut may be formed at a position shifted to one side in the derailment direction from the apex of each of the second cuts.

[0009] In this case, the first cut may be curved in an arc shape, and each of the second cuts may have a curved portion formed in an arc shape including an apex, and a pair of inclined portions extending linearly from both ends of the curved portion while inclining toward the other of the derailment directions so as to move away from each other.

[0010] In this case, the packaging may have a plurality of the cut groups, and the outer ends of adjacent pairs of the cut groups may be formed at positions spaced apart in the opening direction and aligned with the derailment direction.

[0011] The opening structure of the present invention comprises a zipper as described in any one of claims 1 to 5, which is formed in a pair on the paper material with a gap in the derailment direction and with the tops of the first and second cuts facing inward, and a tear strip formed between the pair of zippers.

[0012] The packaging box according to the present invention includes any one of the zippers or the opening structure described above. Effect of the Invention

[0013] According to the present invention, unintentional rupture of the zipper can be suppressed while improving the aesthetic appearance after rupture. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view showing a packaging box according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is a plan view showing a blank for a packaging box according to a first embodiment of the present invention. [Diagram 3] FIG. 2 is an enlarged plan view showing a part (zipper) of the blank for the packaging box according to the first embodiment of the present invention. [Figure 4] 1 is a perspective view showing a state in which a packaging box according to a first embodiment of the present invention has been opened. [Diagram 5] FIG. 2 is a front view illustrating the function of a zipper of the packaging box according to the first embodiment of the present invention. [Figure 6] FIG. 11 is a perspective view showing a packaging box according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a plan view showing a blank for a packaging box according to a second embodiment of the present invention. [Figure 8] FIG. 11 is an enlarged plan view showing a part (opening structure) of a blank of a packaging box according to a second embodiment of the present invention. [Figure 9] FIG. 11 is a perspective view showing a state in which a packaging box according to a second embodiment of the present invention has been opened. [Figure 10] FIG. 11 is an enlarged plan view showing a part (opening structure) of the blank of the packaging box according to a modified example of the second embodiment of the present invention. [Figure 11] FIG. 11 is an enlarged plan view showing a portion of a zipper according to a modified example of the present invention. [Figure 12] FIG. 11 is an enlarged plan view showing a portion of a zipper according to another modified example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. Note that Fr, Rr, L, R, U, and D shown in the drawings indicate front, rear, left, right, top, and bottom. The front-rear direction, left-right direction, and top-bottom direction are mutually perpendicular. Terms indicating directions and positions are used in this specification, but these terms are used for convenience of explanation and do not limit the technical scope of the present invention. In addition, the terms indicating directions and positions are based on the directions and positions in the state in which the packaging box is used.

[0016] [Packaging box according to the first embodiment] A packaging box 1 according to a first embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a perspective view showing the packaging box 1. Fig. 2 is a plan view showing a blank 1A of the packaging box 1.

[0017] As shown in FIG. 1, the packaging box 1 is an A-type box formed in a substantially rectangular parallelepiped shape and sealed by closing both upper and lower end faces of the peripheral wall W. The packaging box 1 is formed by assembling a blank 1A shown in FIG. 2. The blank 1A is formed by punching out a single piece of paper-made corrugated cardboard sheet with a die or the like. The corrugated cardboard sheet is, for example, a double-sided corrugated cardboard sheet in which a front liner 9B and a back liner 9C (see also FIG. 4) are bonded to a corrugated core 9A. Note that FIG. 2 shows the front liner 9B side (the outer surface of the packaging box 1). In this specification, the direction parallel to the core 9A of the corrugated cardboard sheet is called the "step direction", and the direction perpendicular to the step direction is called the "flow direction". In the drawings, "X" indicates the "step direction", and "Y" indicates the "flow direction".

[0018] [blank] 2, the blank 1A includes a pair of first side walls 10, a pair of second side walls 11, a pair of lower inner flaps 12, a pair of lower outer flaps 13, a pair of upper inner flaps 14, and a pair of upper outer flaps 15. Since the pair of first side walls 10 have substantially the same shape, the following description will focus mainly on one first side wall 10. Similarly, the pair of second side walls 11, the pair of lower inner flaps 12, the pair of lower outer flaps 13, the pair of upper inner flaps 14, and the pair of upper outer flaps 15 will be described below focusing mainly on one portion.

[0019] <First side wall, second side wall> A pair of first side walls 10 and a pair of second side walls 11 are alternately arranged in the flow direction via a first folding line L1. The first side walls 10 and the second side walls 11 are formed in a substantially rectangular shape. In detail, the first side walls 10 are formed in a substantially rectangular shape shorter in the flow direction than the second side walls 11. A joint piece 16 is connected to one end of the second side wall 11 located on one side in the flow direction (left side in FIG. 2) via the first folding line L1. The joint piece 16 may be connected to the other end in the flow direction of the first side wall 10 located on the other side in the flow direction (right side in FIG. 2) (not shown). The order of the pair of first side walls 10 and the pair of second side walls 11 may be interchanged (not shown).

[0020] <Lower inner flap, lower outer flap> The lower inner flap 12 is connected to the other end (lower end) in the step direction of the first side wall 10 via the second fold line L2. The lower inner flap 12 is formed in a substantially rectangular shape, and its dimension in the step direction (extension dimension) is set to be approximately half the dimension in the flow direction of the first side wall 10. The lower outer flap 13 is connected to the other end (lower end) in the step direction of the second side wall 11 via the second fold line L2. The lower outer flap 13 is formed in a substantially rectangular shape, and its extension dimension is approximately the same as the extension dimension of the lower inner flap 12.

[0021] <Upper inner flap, upper outer flap> The upper inner flap 14 is connected to one end (upper end) in the step direction of the first side wall 10 via a zipper 20. The upper inner flap 14 is formed in substantially the same shape as the lower inner flap 12. The upper outer flap 15 is connected to one end (upper end) in the step direction of the second side wall 11 via a zipper 20. The upper outer flap 15 is formed in substantially the same shape as the lower outer flap 13.

[0022] The first fold line L1 and the second fold line L2 are general-purpose creases that flatten the cardboard sheet in the thickness direction from the back liner 9C side. The general-purpose creases mainly have the function of folding the cardboard sheet so that the back liner 9C faces inward (forward folding). The first and second fold lines L1 and L2 are not limited to general-purpose creases, and may be any structure for folding the cardboard sheet, such as lead creases with perforations on the general-purpose creases.

[0023] [zipper] Next, the zipper 20 will be described with reference to Figures 2 and 3. Figure 3 is an enlarged plan view showing a part (zipper 20) of the blank 1A.

[0024] Each zipper 20 has a function of folding each upper flap 14, 15 against each side wall 10, 11 and a function of separating each upper flap 14, 15 from each side wall 10, 11. This zipper 20 can be broken from either one side of the flow direction. Note that an example of the "opening direction" referred to in the claims is the flow direction (horizontal direction), and an example of the "derailment direction" perpendicular to the opening direction on a plane is the step direction (vertical direction).

[0025] 2, the zipper 20 is composed of multiple cut line groups 21. The zipper 20 formed at the boundary between the first side wall 10 and the upper inner flap 14 is composed of two cut line groups 21, and the zipper 20 formed at the boundary between the second side wall 11 and the upper outer flap 15 is composed of three cut line groups 21. Since the multiple cut line groups 21 each have the same structure, the following description will mainly focus on one cut line group 21.

[0026] The group of cuts 21 is formed by cutting a first cut 22 and a pair of second cuts 23 into a cardboard sheet (paper material) at a distance in the flow direction (opening direction). Note that the zipper 20 has a pair of straight cuts 24 cut parallel to the flow direction on both sides of the zipper 20 in the flow direction, but the pair of straight cuts 24 may be omitted.

[0027] <First cut> 3, the first cut 22 is curved in an arc shape protruding toward the tip side (one side in the derailment direction) of each upper flap 15 (14). The first cut 22 is formed in a mountain shape that is line-symmetrical with respect to a first center line CL1 (a line that bisects the first cut 22 in the flow direction) that extends along the row direction (derailment direction).

[0028] <Second cut> The pair of second cuts 23 are disposed on both sides of the first cut 22 in the flow direction (opening direction) and are shaped to be line-symmetrical about the first cut 22. The pair of second cuts 23 protrude toward the tip side (one side in the derailment direction) of each upper flap 15 (14), and are formed in a mountain shape that is asymmetrical with respect to a second center line CL2 (a line that bisects the second cut 23 in the flow direction) that protrudes toward the tip side (one side in the derailment direction) of each upper flap 15 (14) and extends along the stage direction (derailment direction). In other words, each of the second cuts 23 is formed in a substantially V-shape.

[0029] Each of the second cuts 23 has a curved portion 23A and a pair of inclined portions 23B. The curved portion 23A is formed in an arc shape including the apex T2. The pair of inclined portions 23B extend linearly from both ends of the curved portion 23A while inclining toward each side wall 11 (10) side (the other side of the derailment direction) so as to move away from each other. In detail, the inclined portion 23B away from the first cut 22 is formed longer than the inclined portion 23B closer to the first cut 22, and extends so as to bite into each side wall 11 (10). In addition, the tip side (outer end portion 27 described later) of the inclined portion 23B away from the first cut 22 is bent so as to be approximately horizontal (parallel to the flow direction).

[0030] <Positional relationship between the first and second cuts> Both ends 25 of the first cut 22 and the inner ends 26 of a pair of second cuts 23 adjacent to both ends of the first cut 22 are formed at positions spaced apart in the flow direction (opening direction). In addition, the outer ends 27 of the pair of adjacent cut groups 21 (pair of second cuts 23) are formed at positions spaced apart in the flow direction (opening direction). In other words, seams 28 connecting the upper flaps 15 (14) and the side walls 11 (10) are formed between the cuts 22, 23. Seams 28 are also formed between the straight cuts 24 and the second cuts 23, and between the vertical edges of the flaps 15 (14) and the straight cuts 24.

[0031] In addition, both ends 25 of the first cut 22, the inner ends 26 of the pair of second cuts 23, and the outer ends 27 of the pair of second cuts 23, which are both ends in the flow direction (opening direction), are formed at positions shifted from each other in the step direction (derailment direction). Specifically, the inner ends 26 of the pair of second cuts 23 are formed at positions shifted from both ends 25 of the first cut 22 to one side in the step direction (the tip side of each upper flap 15 (14)) and shifted from the apex T1 of the first cut 22 to the other side in the step direction (the side of each side wall 11 (10)). In other words, the inner ends 26 of each second cut 23 are disposed above the ends 25 of the first cut 22 by the step D1 (closer to the apex T1). On the other hand, outer ends 27 of the pair of second cuts 23 are formed at positions shifted toward the other side in the step direction (toward each side wall 11 (10) side) from both end portions 25 of the first cuts 22. In other words, the outer ends 27 of each of the second cuts 23 are disposed below the end portions 25 of the first cuts 22 by the step D2 (away from the apex T1).

[0032] Additionally, outer ends 27 of a pair of adjacent cut groups 21 (second cuts 23) are formed at positions that coincide with the row direction (derailment direction). Additionally, each straight cut 24 is formed at a position that coincides with an inner end 26 of the second cut 23 in the row direction. In this specification, "coincidence" does not mean that perfect coincidence is required, but rather means that slight manufacturing errors are allowed.

[0033] The first cuts 22 protrude more than the second cuts 23, and the apex T1 of the first cuts 22 is formed at a position shifted to one side in the step direction (toward the tip end of each upper flap 15 (14)) than the apex T2 of each of the second cuts 23. In other words, the apex T1 of the first cuts 22 is disposed above the apex T2 of the second cuts 23 by the step D3.

[0034] [Sealing the packaging box] Next, the assembly procedure (sealing procedure) of the packaging box 1 will be described with reference to FIG. 1. The packaging box 1 may be sealed manually by an operator, or automatically or semi-automatically by an automatic box-making machine (not shown). Here, as an example, a case where the packaging box 1 is sealed manually by an operator will be described. In addition, as the initial state of the packaging box 1, the first side wall 10 and the second side wall 11 located on both outer sides in the flow direction of the blank 1A are folded back at the first folding line L1, the joint piece 16 is adhered to the back liner 9C of the folded back first side wall 10, and the packaging box 1 is folded in half (not shown).

[0035] The worker folds the pair of first side walls 10 and the pair of second side walls 11 at approximately right angles along the first fold line L1 to form a rectangular tubular peripheral wall W. Next, the worker folds the pair of lower inner flaps 12 inward along the second fold line L2, and then folds the pair of lower outer flaps 13 inward along the second fold line L2. The tips of the pair of lower inner flaps 12 are spaced apart, and the tips of the pair of lower outer flaps 13 are butted together. The pair of lower outer flaps 13 are fixed to the front liner 9B of the pair of lower inner flaps 12 via an adhesive.

[0036] As a result, the pair of lower inner flaps 12 and the pair of lower outer flaps 13 form the bottom wall of the peripheral wall W. An operator places an article (not shown) inside the peripheral wall W through an upper opening thereof.

[0037] Next, the worker folds the pair of upper inner flaps 14 inward along the zipper 20, and then folds the pair of upper outer flaps 15 inward along the zipper 20. The tips of the pair of upper inner flaps 14 are spaced apart, and the tips of the pair of upper outer flaps 15 are butted together. The pair of upper outer flaps 15 are fixed to the front liner 9B of the pair of upper inner flaps 14 via an adhesive.

[0038] As a result, the pair of upper inner flaps 14 and the pair of upper outer flaps 15 form the top wall of the peripheral wall W. The packaging box 1 is sealed (see FIG. 1). In the above description, the upper and lower outer flaps 13, 15 are fixed to the inner flaps 12, 14 with adhesive, but this is not limiting and the outer flaps 13, 15 may be fixed by applying adhesive tape along the butt joints (not shown).

[0039] [Opening the packaging box] Next, a procedure for opening the packaging box 1 will be described with reference to Figures 4 and 5. Figure 4 is a perspective view showing the state after the packaging box 1 has been opened. Figure 5 is a front view explaining the function of the zipper 20.

[0040] 4, the user peels the pair of upper outer flaps 15 from the pair of upper inner flaps 14, and opens the pair of upper outer flaps 15 and the pair of upper inner flaps 14 to an upright position. In this state, the packaging box 1 is opened, but the upper flaps 14, 15 of the packaging box 1 can be separated along the zipper 20.

[0041] Since the pair of upper inner flaps 14 and the pair of upper outer flaps 15 can be separated in the same procedure, the following description will take as an example a procedure for separating the front upper outer flaps 15. As already explained, the zipper 20 can be torn from either side in the lateral direction (opening direction), but since the tearing action (phenomenon) is the same regardless of which side it is torn from, the case where it is torn from left to right will be described as an example.

[0042] The user grasps the left side of the upper outer flap 15 and pulls the upper outer flap 15 from left to right. Then, the multiple seams 28 formed in the zipper 20 are broken in sequence from left to right. Here, a tear G caused by the breakage of each seam 28 tends to deviate toward the tip side of the upper outer flap 15 being separated from the left to the right. In other words, the tear G has a tendency to deviate diagonally upward to the right (see the dashed line in FIG. 5).

[0043] As shown in FIG. 5, immediately after the upper outer flap 15 starts to be divided, a tear G(1) proceeding from the straight cut 24 reaches the outer inclined portion 23B of the adjacent second cut 23 while diverging diagonally upward to the right. Next, a tear G(2) proceeding from the inner end 26 of the second cut 23 reaches the adjacent first cut 22 (left side of the apex T1) while diverging diagonally upward to the right. Next, a tear G(3) proceeding from the end 25 of the first cut 22 reaches the inner inclined portion 23B (inner end 26) of the adjacent second cut 23 while diverging diagonally upward to the right. Furthermore, a tear G(4) proceeding from the outer end 27 of the second cut 23 reaches the second cut 23 of another adjacent cut group 21 while diverging diagonally upward to the right.

[0044] As described above, when the tear G traveling along the seam 28 reaches the adjacent cuts 22, 23, the derailment of the tear G is interrupted. As a result, the upper outer flap 15 is severed from the second side wall 11 along the zipper 20 (see FIG. 4). The user then severs the remaining flaps 14, 15 from the side walls 10, 11 in the same manner as described above (not shown).

[0045] In the packaging box 1 according to the first embodiment described above, the first cut 22 and the second cut 23 of the zipper 20 are spaced apart in the horizontal direction (opening direction) and are arranged in staggered steps in the vertical direction. This configuration ensures that the seam 28 between the first cut 22 and the second cut 23 is wide. This makes it possible to prevent unintended breakage, such as tearing of the seam 28 due to impact during transportation, for example. In addition, the pair of second cuts 23 are arranged line-symmetrically about the first cut 22, so that the zipper 20 can be broken from either one side or the other side in the horizontal direction.

[0046] If a zipper were to be formed so that adjacent cuts overlap at close positions, the seams would be very narrow and prone to breaking, and therefore could not be used as fold lines at the boundaries between each side wall 10, 11 and each flaps 14, 15. In contrast, with the zipper 20 described above, seam 28 can be ensured to be wide, so zipper 20 can be used in place of the fold lines of each flaps 14, 15.

[0047] In addition, in the zipper 20 described above, the first cut 22 and the second cut 23 are formed in a mountain shape that protrudes in the same direction, so the trace (fracture surface) of the zipper 20 when broken is generally wavy (see FIG. 4). This makes it possible to make the fracture surface less uneven compared to a zigzag fracture surface, and improves the aesthetic appearance after breaking.

[0048] Incidentally, such a zipper 20 is formed by pressing a die (not shown) with a blade fixed to a plywood against a cardboard sheet. If adjacent first cut 22 and second cut 23 are opposed to each other so that a part of the first cut 22 and the second cut 23 are close to each other and overlap each other, the plywood part between the blades cutting the first cut 22 and the second cut 23 becomes thin, and it may not be possible to ensure the rigidity (strength) required to support the blades. In contrast, the zipper 20 described above can ensure a wide seam 28, so that the width of the plywood part between the blades cutting the first cut 22 and the second cut 23 can also be widened. This makes it possible to manufacture an appropriate die that holds the blades securely.

[0049] In the zipper 20 described above, the inner end 26 of the second cut 23 is located between the apex T1 and the end 25 of the first cut 22. With this configuration, for example, when the seam 28 is torn from left to right, a tear G(2) that tries to deviate diagonally upward to the right from the inner end 26 of the second cut 23 on the left reaches the first cut 22, and a tear G(3) that tries to deviate diagonally upward to the right from the end 25 of the first cut 22 reaches the second cut 23 on the right (see FIG. 5). This effectively prevents the tear G from deviating from the cuts 22, 23 and progressing.

[0050] In addition, according to the zipper 20 described above, the first cut 22 protrudes higher than the second cut 23, so that the tear G(2) that deviates obliquely upward from the inner end 26 of the second cut 23 can easily reach the first cut 22 (see FIG. 5). This makes it possible to effectively prevent the tear G from derailing.

[0051] If the apex T1 of the first cut 22 and the apex T2 of the second cut 23 were not curved but bent as if a straight line had been bent, force would be easily concentrated on the apexes T1 and T2 when opening the cardboard sheet, which could cause the cardboard sheet to tear at the apexes T1 and T2. In contrast, with the zipper 20 described above, the apexes T1 and T2 are curved, which disperses the force acting on the apexes T1 and T2 and prevents the cardboard sheet from breaking at the apexes T1 and T2. In addition, the broken surface can be made naturally wavy with rounded edges (see FIG. 4).

[0052] In the zipper 20 described above, each second cut 23 is formed in a mountain shape, and the outer ends 27 of each pair of adjacent cut groups 21 are spaced apart horizontally and arranged without any steps vertically. With this configuration, for example, when the zipper 20 is torn from left to right, the tear G(4) that tries to deviate diagonally upward to the right from the outer end 27 of the left cut group 21 reaches the second cut 23 of the right cut group 21, preventing the tear G from derailing (see FIG. 5).

[0053] In the packaging box 1 according to the first embodiment, the zipper 20 is formed at the boundaries between the four side walls 10, 11 and the four flaps 14, 15, but the present invention is not limited to this. The zipper 20 may be formed at at least one boundary between the four side walls 10, 11 and the four flaps 14, 15 (not shown). In this case, the other flaps 14, 15 may be connected to the side walls 10, 11 via general-purpose lines. The zipper 20 may also be formed at the boundaries between each side wall 10, 11 and each lower flap 12, 13 (not shown).

[0054] [Packaging box according to the second embodiment] Next, a packaging box 2 (blank 2A) according to a second embodiment will be described with reference to Figs. 6 to 9. Fig. 6 is a perspective view showing the packaging box 2. Fig. 7 is a plan view showing the blank 2A. Fig. 8 is an enlarged plan view showing a part (opening structure 30) of the blank 2A. Fig. 9 is a perspective view showing the packaging box 2 in an opened state. In the following description, the same reference numerals are used for configurations similar or corresponding to those of the packaging box 1 (zipper 20) according to the first embodiment, and similar or corresponding descriptions will be omitted.

[0055] As shown in Figures 6 and 7, in the packaging box 2 (blank 2A) of the second embodiment, each of the upper flaps 14, 15 is connected to each of the side walls 10, 11 via a third fold line L3 (e.g., a general-purpose line), and an opening structure 30 including a pair of zippers 20 is formed in each of the side walls 10, 11.

[0056] The opening structure 30 includes a pair of zippers 20 and a tear strip 31. The pair of zippers 20 are formed on the pair of first side walls 10 and the pair of second side walls 11 at an interval in the row direction (derailing direction). The pair of zippers 20 are formed to cross the entire blank 2A ​​in the flow direction slightly below the center of the row direction of each side wall 10, 11. The pair of zippers 20 are arranged so that the tops T1, T2 of the cuts 22, 23 face each other and are arranged approximately parallel to each other (see also FIG. 8). The tear strip 31 is formed between the pair of zippers 20. A vertical cut 32 is cut in the center of the tear strip 31 formed on each second side wall 11 in the flow direction so as to connect the pair of upper and lower first cuts 22. In addition, a pair of perforations 33 is cut in the joint piece 16 so as to extend continuously from the pair of zippers 20 (see FIG. 7).

[0057] The packaging box 2 is assembled (sealed) in the same manner as the packaging box 1 according to the first embodiment. The tear strip 31 (the pair of zippers 20) is formed on the entire circumference of the peripheral wall W. When opening the packaging box 2, a user inserts a finger into a vertical slit 32 formed on the tear strip 31 of the second side wall 11, grasps an end of the tear strip 31 separated by the vertical slit 32, and pulls the tear strip 31 in the horizontal direction. Then, the user separates the tear strip 31 from each side wall 10, 11 along the pair of zippers 20.

[0058] Here, the tear G caused by the breakage of each seam 28 tends to deviate toward the tear strip 31 (see the broken lines in FIG. 8). That is, the pair of upper and lower tear strips G tend to derail in the direction of approaching each other. For example, when the tear strip 31 is broken from left to right, as shown in FIG. 8, the tear strip G(3) deviating from the end 25 of the first cut 22 to the inside reaches the second cut 23, the tear strip G(4) deviating from the outer end 27 of the second cut 23 to the inside reaches the second cut 23 of the other cut group 21, and the tear strip G(2) deviating from the inner end 26 of the second cut 23 to the inside reaches the first cut 22. This prevents the tear strip 31 from tearing as the tear strip G derails and advances from each cut 22, 23.

[0059] 9, the tear strip 31 is separated from the side walls 10, 11, dividing the packaging box 2 into two parts, an upper part and a lower part. The upper part of the packaging box 2 is removed, and the tray-like lower part of the packaging box 2 containing the articles is displayed in a store, etc. The packaging box 2 may be opened by opening the upper flaps 14, 15 (not shown).

[0060] According to the packaging box 2 (opening structure 30) of the second embodiment described above, it is possible to obtain the same effects as the packaging box 1 (zipper 20) of the first embodiment described above, such as suppressing unintentional breakage while improving the aesthetic appearance after breakage.

[0061] In the packaging box 2 according to the second embodiment, the pair of upper and lower zippers 20 are arranged at the same pitch in the horizontal direction, and the tops T1, T2 of the cuts 22, 23 face each other, but the present invention is not limited to this. For example, as shown in Fig. 10, the pair of upper and lower zippers 20 may be shifted by half a pitch in the horizontal direction. In detail, the tops T1, T2 of one zipper 20 may face the seam 28 of the other zipper 20.

[0062] In addition, in the packaging box 2 according to the second embodiment, the pair of upper and lower zippers 20 are arranged substantially parallel to each other, but this is not limited thereto, and they may be arranged at an angle to each other (not shown). In addition, the tear strip 31 (pair of zippers 20) is formed substantially horizontally, but this is not limited thereto, and they may be formed at an angle (not shown).

[0063] In the packaging box 2 according to the second embodiment, the tear strip 31 (the pair of zippers 20) is formed so as to go around the peripheral wall W, but the present invention is not limited to this. For example, the tear strip 31 (the pair of zippers 20) may be formed only on one second side wall 11, and one zipper 20 may be formed on the other side walls 10, 11 so as to be continuous with the zipper 20 below the tear strip 31 (not shown).

[0064] In the packaging boxes 1 and 2 according to the first and second embodiments, the zipper 20 is composed of a plurality of cut line groups 21, but this is not limited thereto and may be composed of a single cut line group 21 (not shown). In addition, the zipper 20 (tear strip 31) is extended in the horizontal direction, but this is not limited thereto and may be extended in the vertical direction or diagonally (not shown).

[0065] In the packaging boxes 1 and 2 according to the first and second embodiments, the inner end 26 of each second cut 23 is disposed at a height between the end 25 of the first cut 22 and the apex T1, and the outer end 27 of each second cut 23 is disposed below the end 25 of the first cut 22 (or outside the tear strip 31), but the present invention is not limited thereto. For example, the outer end 27 of each second cut 23 may be disposed above the inner end 26 of each second cut 23 and the end 25 of the first cut 22 (or inside the tear strip 31) (not shown). For example, the inner end 26 of each second cut 23 may be disposed below the end 25 of the first cut 22 (or outside the tear strip 31), and the outer end 27 of each second cut 23 may be disposed at a height between the inner end 26 and the end 25 of the first cut 22 (not shown). In addition to these, both end portions 25 of the first cut 22, the inner end portions 26 of the pair of second cuts 23, and the outer end portions 27 of the pair of second cuts 23 may be arranged so as to be staggered relative to each other in the step direction (up and down direction).

[0066] In the packaging boxes 1 and 2 according to the first and second embodiments, the apex T1 of the first cut 22 is located above the apex T2 of each of the second cuts 23 (inside the tear strip 31), but the present invention is not limited to this. The apex T1 of the first cut 22 may be located below the apex T2 of each of the second cuts 23 (outside the tear strip 31) (not shown).

[0067] In the packaging boxes 1 and 2 according to the first and second embodiments, the first cut 22 is formed in an arc shape, but the present invention is not limited thereto. For example, the first cut 22 may be formed in a folded line shape (approximately triangular) bent at the apex T1 (see FIG. 11), or may be formed in an approximately trapezoid shape having a straight line including the apex T1 (see FIG. 12). Like the first cut 22, the second cut 23 is also formed in an arc shape near the apex T2, but the present invention is not limited thereto, and may be formed in an approximately triangular shape (see FIG. 11), or may be formed in an approximately trapezoid shape (see FIG. 12). In addition, the first and second cuts 22 and 23 having an arc shape, a triangular shape, a trapezoid shape, or the like may be combined to form the cut group 21 (not shown). In addition, the zipper 20 having these first and second cuts 22 and 23 may be applied to the opening structure 30 (not shown).

[0068] In addition, in the packaging boxes 1, 2 according to the first and second embodiments, the outer end 27 of the second cut 23 is bent so as to be approximately horizontal, but this is not limited thereto, and the tip of an inclined straight portion may be the outer end 27, similar to the inner end 26 (not shown).

[0069] In addition, in the packaging boxes 1, 2 according to the first and second embodiments, the outer ends 27 of a pair of adjacent cut groups 21 are aligned in the row direction (vertical direction), but this is not limited thereto and they may be slightly misaligned in the row direction (vertical direction) (not shown).

[0070] In addition, the packaging boxes 1 and 2 according to the present embodiment are formed from a double-sided corrugated cardboard sheet made of paper, but the present invention is not limited to this. The packaging boxes 1 and 2 may be formed from single-sided corrugated cardboard, double-sided corrugated cardboard, or triple-sided corrugated cardboard, or may be formed from single paper (thick paper), etc. In addition, the packaging boxes 1 and 2 according to the present embodiment are A-type corrugated cardboard boxes, but the box type may be freely changed.

[0071] The above embodiment shows one aspect of the zipper, the opening structure, and the packaging box according to the present invention, and the technical scope of the present invention is not limited to the above embodiment. The technical scope of the present invention is not limited to the above embodiment. The present invention may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea, and the claims include all embodiments that may be included within the scope of the technical idea. [Explanation of symbols]

[0072] 1,2 Packaging box 20 Zipper 21 Cut group 22 First cut 23 Second cut 23A curved section 23B Slope 25 (First cut) end 26 (2nd cut) inner end 27 (2nd cut) outer end 30 Unpacking structure 31 Tear zone CL1 1st center line CL2 2nd center line T1 (Top of first cut) T2 (top of second cut)

Claims

1. A zipper (20) comprising at least one group of cuts (21) formed by cutting a first cut (22) and a pair of second cuts (23) into a paper material at intervals in the opening direction, The first cut is formed in a mountain shape that protrudes in one direction in a derailment direction perpendicular to the opening direction on a plane, and is symmetrical with respect to a first center line (CL1) extending along the derailment direction, a pair of the second cuts are disposed on both sides of the first cut in the opening direction, and are shaped to be line-symmetrical about the first cut, each protruding to one side in the derailment direction, and formed in a mountain shape that is asymmetrical with respect to a second center line (CL2) extending along the derailment direction; Both ends (25) of the first cut and inner ends (26) of a pair of the second cuts adjacent to both ends of the first cut are formed at positions spaced apart in the opening direction, the two ends of the first cut, the inner ends of the pair of second cuts, and the outer ends (27) of the pair of second cuts which are both ends in the opening direction are formed at positions shifted from each other in the derailment direction.

2. the inner ends of the pair of second cuts are formed at positions shifted in one direction in the derailment direction from the both ends of the first cuts and shifted in the other direction in the derailment direction from apexes (T1) of the first cuts, 2. The zipper according to claim 1, wherein the outer ends of the pair of second cuts are formed at positions shifted toward the other of the two ends of the first cuts in the derailment direction.

3. 3. The zipper according to claim 1, wherein the apexes (T1) of the first cuts are formed at positions shifted in one direction in the derailment direction from the apexes (T2) of the second cuts.

4. The first cut is curved in an arc shape, Each of the second cuts comprises: A curved portion (23A) formed in an arc shape including an apex (T2); 4. The zipper according to claim 1, further comprising a pair of inclined portions (23B) extending linearly from both ends of the curved portion and inclining in the other direction of the derailment so as to move away from each other.

5. 5. The zipper according to claim 1, further comprising a plurality of the cut line groups, the outer ends of a pair of adjacent cut line groups being formed at positions spaced apart in the opening direction and aligned in the derailing direction.

6. The zipper according to any one of claims 1 to 5, wherein a pair of the first cut and the second cut are formed on the paper material with apexes (T1, T2) facing inward and spaced apart in the derailment direction; and a tear strip (31) formed between the pair of zippers.

7. A packaging box comprising the zipper according to any one of claims 1 to 5 or the opening structure according to claim 6.

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