Packaging container

Abstract

To provide a packaging container in which even if a flexural deformation occurs in a hinge wall in a closed state, the influence of the deformation is reduced and a lid can be easily opened.SOLUTION: An openable and closable packaging container 1 which has a container portion 11 and a lid portion 12 and in which mutual parts thereof are connected to form a hinge wall 13, includes: a linear first slit 131 formed at a boundary 13a in the hinge wall 13; a linear second slit 132 formed in the hinge wall 13 with an interval between itself and the first slit 131; and a fragile portion 133 made to be easily buckled into the container due to stress when opening the lid, compared to other portions in the hinge wall 13 by that a plurality of slit portions 133a extending from one slit side to the other slit side without contacting both slits between the first slit 131 and the second slit 132 are arranged along the boundary 13a and formed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an openable and closable packaging container having a container portion and a lid portion. [Background technology]

[0002] Conventionally, openable and closable packaging containers having a container part and a lid part have been widely used in various stores (see, for example, Patent Document 1). In the packaging container described in Patent Document 1, a hinge wall is formed by foldably connecting a part of the peripheral wall of the container part and a part of the peripheral wall of the lid part. The boundary between the container side wall part and the lid side wall part of this hinge wall is a folding line, and the lid part is opened and closed. At this time, the packaging container is stored in an open state, and a slit is formed in the center of the hinge wall except for both ends at the folding line in order to maintain the open state during storage. This slit reduces the force acting in the direction from the open position of the lid part to the closed position, and the open state is effectively maintained. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-032175 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned openable and closable packaging container, a user opens the lid of the packaging container that contains a product in a closed state and removes the product. At this time, the hinge wall in the closed state may bend and deform convexly outward due to the pressure exerted by the contained product on the peripheral walls of the container and lid from the inside, or due to the way in which the user applies force when holding the packaging container. When such bending deformation occurs in the hinge wall, the folding line of the hinge wall, which serves as the opening and closing axis, may bend, making it difficult to open the lid.

[0005] Here, in the packaging container described in the above-mentioned Patent Document 1, a slit is formed in the center of the folding line, and only the two ends of the folding line essentially function as the opening and closing axis, so at first glance it seems that the effect of bending deformation of the hinge wall is reduced. However, if bending deformation occurs in the hinge wall, the edge of the container side and the edge of the lid side that are bent outwardly convexly at the slit may interfere with each other, making it more difficult to open the lid.

[0006] The present invention has an object to solve such a problem, that is, to provide a packaging container in which, even if bending deformation occurs in the hinge wall in the closed state, the influence of the bending deformation is reduced and the lid portion can be easily opened. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the packaging container is an openable packaging container having a container portion and a lid portion each formed into an open box shape from a sheet material, and a container side wall portion forming part of the peripheral wall of the container portion and a lid side wall portion forming part of the peripheral wall of the lid portion are foldably connected to each other at their opening side edges to form a hinge wall, and is characterized in that the packaging container is provided with a first slit formed at the boundary between the container side wall portion and the lid side wall portion so as to extend along the boundary, a second slit formed in the hinge wall so as to extend along the first slit while leaving a gap between the first slit and the second slit, and a fragile portion which is more likely to buckle into the inside of the container due to stress when the lid is opened than other portions of the hinge wall, Effect of the Invention

[0008] According to the packaging container described above, even if bending deformation occurs in the hinge wall in the closed state, the influence of the bending deformation is reduced and the lid can be easily opened. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view of a packaging container according to one embodiment in a closed state, as viewed from the hinge wall side. [Diagram 2] 2 is a top view of the packaging container in the closed state shown in FIG. 1, as viewed from the direction of arrow V11 in FIG. 1 (the lid side). [Diagram 3] 2 is a bottom view of the packaging container in the closed state shown in FIG. 1, as viewed from the direction of arrow V12 in FIG. 1 (the bottom wall side of the container portion). [Figure 4] 2 is a right side view of the packaging container in the closed state shown in FIG. 1, as viewed in the direction of arrow V13 in FIG. 1 (the right side when facing the engagement side of the container part and the lid part). FIG. [Diagram 5] 2 is a front view of the packaging container in the closed state shown in FIG. 1, as viewed in the direction of arrow V14 in FIG. 1 (the engagement side of the container portion and the lid portion). [Figure 6] 2 is a rear view of the packaging container in the closed state shown in FIG. 1, as viewed from the direction of arrow V15 in FIG. 1 (the hinge wall side). [Figure 7] FIG. 7 is a plan view showing a blank sheet in which the packaging container shown in FIGS. 1 to 6 is unfolded. [Figure 8] FIG. 8 is a perspective view showing the packaging container shown in FIGS. 1 to 7 in a state on the way to an open state, as seen from the same direction as FIG. [Figure 9] FIG. 13 is a diagram showing first to sixth modified examples of a weakened shape formed by a plurality of slit portions in the weakened portion of the hinge wall. [Figure 10] 13 is a diagram showing a seventh modified example of a weakened shape formed by a plurality of slit portions in the weakened portion of the hinge wall. FIG. [Figure 11] 13 is a diagram showing eighth to tenth modified examples relating to a first slit and a second slit. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, one embodiment of a packaging container having a hinge wall and capable of being opened and closed will be described.

[0011] FIG. 1 is a perspective view of a packaging container according to one embodiment in a closed state, as viewed from the hinge wall side. FIG. 2 is a top view of the packaging container in the closed state shown in FIG. 1, as viewed from the direction of the arrow V11 (the lid side) in FIG. 1, and FIG. 3 is a bottom view of the packaging container in the closed state shown in FIG. 1, as viewed from the direction of the arrow V12 (the bottom wall side of the container part) in FIG. 1. FIG. 4 is a right side view of the packaging container in the closed state shown in FIG. 1, as viewed from the direction of the arrow V13 (the right side toward the engagement side of the container part and the lid part) in FIG. 1. FIG. 5 is a front view of the packaging container in the closed state shown in FIG. 1, as viewed from the direction of the arrow V14 (the engagement side of the container part and the lid part) in FIG. 1, and FIG. 6 is a rear view of the packaging container in the closed state shown in FIG. 1, as viewed from the direction of the arrow V15 (the hinge wall side) in FIG. 1. And FIG. 7 is a plan view showing a blank sheet in which the packaging containers shown in FIGS. 1 to 6 are unfolded.

[0012] The packaging container 1 of this embodiment is an openable container made of a sheet material such as paper that is provided to users in a fast food restaurant or the like while containing a product in a closed state, and is manufactured by folding a blank sheet 1a cut out in its unfolded shape as shown in Fig. 7. This packaging container 1 has a container section 11 and a lid section 12, each of which is made of a sheet material and shaped like a rectangular open box.

[0013] The container 11 has a rectangular bottom wall 111, and a pair of container side walls 112a, a container side front wall 112b, and a container side rear wall 112c that are folded up from each of the four sides to form the container side peripheral wall 112. A container side lock piece 112a-1 with which the lid 12 engages is provided on the front side of each container side wall 112a. A pair of side edges of the container side front wall 112b are provided with container front side folding pieces 112b-1 that are folded inside the pair of container side walls 112a and adhesively fixed to the inner surface of each container side wall 112a. The container side rear wall 112c is a portion to which the lid 12 is connected so as to be able to be folded at its opening side edge. A pair of side edges of the container side rear wall 112c are provided with container rear side folding pieces 112c-1 that are folded inside the pair of container side walls 112a and adhesively fixed to the inner surface of each container side wall 112a. In forming the container portion 11, first, a pair of container side walls 112a, a container side front wall 112b, and a container side rear wall 112c are folded up from the four sides of the bottom wall 111 of the blank sheet 1a. Then, a container front side fold-in piece 112b-1 and a container rear side fold-in piece 112c-1 are folded into the inner surface of the container side side wall 112a and glued and fixed to form a rectangular cylindrical container side peripheral wall 112 surrounding the bottom wall 111. This forms the container portion 11 having a pair of container side lock pieces 112a-1 on the front side.

[0014] The lid 12 has a rectangular ceiling wall 121, and a pair of lid side walls 122a, a lid front wall 122b, and a lid rear wall 122c that are folded up from each of the four sides to form the lid peripheral wall 122. The front side of each lid side wall 122a is provided with a lid front folding piece 122a-1 that is folded inside the lid front wall 122b and adhesively fixed to the inner surface of the lid front wall 122b. The lid front wall 122b is a portion that engages with the container 11, and a pair of lid lock pieces 122b-1 that engage with the pair of container lock pieces 112a-1 are provided at a pair of corners on the opening side of the lid front wall 122b. The lid rear wall 122c is a portion to which the container rear wall 112c is foldably connected to its opening edge. A pair of side edges of the lid-side rear wall 122c are provided with lid-side back-folding pieces 122c-1 that are folded inside the pair of lid-side side walls 122a and adhesively fixed to the inner surface of each of the lid-side side walls 122a. In forming the lid portion 12, first, a pair of lid-side side walls 122a, a lid-side front wall 122b, and a lid-side rear wall 122c are folded up from the four sides of the ceiling wall 121 of the blank sheet 1a. Furthermore, the lid-side front-folding piece 122a-1 is folded into the inner surface of the lid-side front wall 122b, and the lid-side back-folding piece 122c-1 is folded into the inner surface of the lid-side side wall 122a, and each is adhesively fixed to form a rectangular cylindrical lid-side peripheral wall 122 surrounding the ceiling wall 121. This forms the lid portion 12 having a pair of lid-side locking pieces 122b-1 on the front side.

[0015] Here, in the packaging container 1, the container-side rear wall 112c and the lid-side rear wall 122c are connected to each other in a foldable manner at their opening side edges to form the hinge wall 13. The container-side rear wall 112c is a container side wall portion that forms part of the container-side peripheral wall 112 in this hinge wall 13. Also, the lid-side rear wall 122c is a lid side wall portion that forms part of the lid-side peripheral wall 122 in this hinge wall 13. In this embodiment, the hinge wall 13 is provided with a first slit 131, a second slit 132, and a fragile portion 133.

[0016] The first slit 131 is a linear slit formed in the center of the boundary 13a between the container-side rear wall 112c and the lid-side rear wall 122c of the hinge wall 13, excluding both end portions.

[0017] The second slit 132 is a linear slit formed in the lid-side rear wall 122c of the hinge wall 13 so as to extend along the first slit 131 with a gap between them.

[0018] The fragile portion 133 is a portion between the first slit 131 and the second slit 132. In the fragile portion 133, a plurality of slit portions 133a are formed, which extend from one of the first slit 131 and the second slit 132 to the other of the first slit 131 and the second slit 132 without contacting both slits, and are arranged along the boundary 13a. Due to the formation of the plurality of slit portions 133a, the fragile portion 133 is more likely to buckle into the container due to stress when the lid is opened than other portions of the hinge wall 13.

[0019] In this embodiment, the multiple slit portions 133a in the fragile portion 133 are oblique with respect to the boundary 13a so that the ends of the first slit 131 and the second slit 132 are alternately adjacent to each other. The multiple slit portions 133a are connected to each other at adjacent ends to form a meandering slit 133b. The meandering slit 133b meanders between the first slit 131 and the second slit 132. The meandering slit 133b meanders in a wavy manner between the first slit 131 and the second slit 132. The multiple slit portions 133a are oblique in a curved shape so as to form a part of the wavy meandering slit 133b. The adjacent ends of the slit portions 133a are connected to each other in an arc shape so that the apex closest to the first slit 131 and the second slit 132 is formed in the meandering slit 133b. As shown in the rear view of FIG. 6, the meandering pitch P11 of the meandering slit 133b is longer than the distance L11 between the first slit 131 and the second slit 132. As shown in the rear view of FIG.

[0020] In the packaging container 1 shown in Figs. 1 to 7, a weak portion 133 between a first slit 131 and a second slit 132 provided in the hinge wall 13 on the rear side assists the opening of the lid portion 12 when the lid is opened.

[0021] FIG. 8 is a perspective view showing the packaging container shown in FIGS. 1 to 7 in the middle of reaching the open state, as viewed from the same direction as FIG.

[0022] When a product is removed from the packaging container 1, the lid side lock piece 122b-1 is disengaged from the container side lock piece 112a-1, and the lid part 12 is opened in the opening direction D11 about the boundary 13a between the container side rear wall 112c and the lid side rear wall 122c of the hinge wall 13. At this time, the fragile part 133 between the first slit 131 and the second slit 132 is easily buckled in the buckling direction D12 toward the inside of the container by the stress at the time of opening the lid, due to the wavy meandering slit 133b formed by the arrangement of the multiple slit parts 133a. Due to the buckling of the fragile part 133, the first slit 131 on the boundary 13a is easily deformed so that the lid side slit edge 131a enters inside the container side slit edge 131b. When such a deformation occurs, the interference between the edges of the first slit 131 at the time of opening the lid is suppressed, and the opening of the lid part 12 at the time of opening the lid is assisted.

[0023] According to the packaging container 1 of the embodiment described above, even if the hinge wall 13 is deformed outward due to pressure from the product inside, the influence of the deformed bending is reduced as follows, and the lid 12 can be easily opened. That is, since the fragile portion 133 is a portion that is likely to buckle toward the inside of the container due to stress when the lid is opened, the edge of the first slit 131 on the side of the fragile portion 133 (lid-side slit edge 131a) is likely to retract into the inside of the container due to the buckling of the fragile portion 133. As a result, the edges of the first slit 131 on the side of the fragile portion 133 and the edges on the other side (container-side slit edge 131b) are likely to bend in opposite directions, and interference between these edges when the lid is opened is reduced. Also, even if the edges of the first slit 131 on the side of the fragile portion 133 are not retracted much and interfere with the edges on the other side, the fragile portion 133 is crushed by the interference, and the resistance to opening the lid 12 is ultimately reduced. Thus, according to the packaging container 1 of this embodiment, even if bending deformation occurs in the hinge wall 13 in the closed state, the effect of this deformation is reduced and the lid portion 12 can be easily opened.

[0024] In this embodiment, the multiple slit portions 133a in the fragile portion 133 are oblique to the boundary 13a, and adjacent ends are connected to form the meandering slit 133b. With this configuration, the meandering slit 133b, which is a continuous slit, makes the fragile portion 133 more likely to buckle when the lid is opened, and the lid portion 12 can be opened even more easily.

[0025] In this embodiment, the meandering pitch P11 of the meandering slit 133b is longer than the interval L11 between the first slit 131 and the second slit 132.

[0026] Regarding the above-mentioned packaging container 1, for example, it is conceivable that the blank sheets 1a processed into an unfolded shape are fed one by one from a sheet bundle of stacked sheets into a box-making machine to mass-produce the packaging containers 1 in an open state. In such a case, if the edges of the meandering slit 133b are easily caught between the topmost blank sheet 1a being fed and the blank sheet 1a immediately below it, the productivity in mass production may be reduced. According to the above-mentioned configuration, since the meandering pitch P11 of the meandering slit 133b is long, the convex shape of the meandering top, which is particularly easily caught when the blank sheet 1a is fed, becomes gentle. As a result, the edges of the meandering slit 133b are less likely to be caught when the blank sheet 1a is fed, and the productivity in mass production can be improved.

[0027] In this embodiment, the meandering slit 133b is a wavy slit. With this configuration, the edges of the meandering slit 133b are formed with wavy and smooth curves, so that the edges of the meandering slit 133b are less likely to get caught when the blank sheet 1a is fed, and the productivity in mass production can be improved.

[0028] In this embodiment, all of the slit portions 133a constituting the meandering slit 133b in the fragile portion 133 extend without any breaks along the way, and adjacent ends are also connected without interruption. This configuration forms a meandering slit 133b that continues continuously without interruption, making the fragile portion 133 more likely to buckle and allowing the lid portion 12 to be opened even more easily.

[0029] Here, the weakened shape of the weakened portion 133 of the hinge wall 13 formed by the plurality of slit portions is not limited to the wavy meandering slits 133b as described above, but may be any of various modified examples as described below.

[0030] Fig. 9 is a diagram showing first to sixth modified examples of a weakened shape formed by a plurality of slits in the weak portion of the hinge wall. In Fig. 9, the same components as those in the above-mentioned embodiment are shown with the same reference numerals as those in the above-mentioned embodiment, and the duplicated description of those components will be omitted below.

[0031] 9(a), a sawtooth-shaped meandering slit 233b is formed by a plurality of slit portions 233a in the weak portion 233 between the first slit 131 and the second slit 132. To form the sawtooth-shaped meandering slit 233b, the plurality of slit portions 233a are formed obliquely in a straight line that alternates in the direction of inclination. Also in this first modified example, the meandering pitch P21 is longer than the interval L11 between the first slit 131 and the second slit 132.

[0032] According to this first modified example, it is easy to shorten the distance between the first slit 131 and the second slit 132 and the serrated serpentine apex, thereby increasing the fragility of the fragile portion 233 and making it easier to open the lid portion 12.

[0033] 9(b), the multiple slit portions 333a in the fragile portion 333 are linearly inclined so that the ends of the first slits 131 and the second slits 132 are adjacent to each other while being spaced apart from each other. In this second modified example, the distance between the ends may be appropriately determined in consideration of the material and thickness of the blank sheet, and may be, for example, 0.5 to 1 mm.

[0034] According to the second modified example, the slit portion 333a of the fragile portion 333 does not have a convex edge that may easily get caught when the blank sheet 1a is fed out, thereby improving productivity in mass production.

[0035] In the third modified example shown in FIG. 9(c), a plurality of slit portions 433a in the weak portion 433 constitute an irregularly wavy meandering slit 433b as follows. In this irregularly wavy meandering slit 433b, one of the first slit 131 and the second slit 132 (the second slit 132 in this modified example) is a first arc portion 433b-1 that is convex toward the slit side and has a relatively large diameter. In addition, the other slit (the first slit 131 in this modified example) is a second arc portion 433b-2 that is convex toward the slit side and has a relatively small diameter. The meandering slit 433b in this modified example is formed by alternating the first arc portion 433b-1 and the second arc portion 433b-2 that have different diameters.

[0036] According to this third modification, the formation of the large-diameter first arc portion 433b-1 can prevent the edges of the meandering slit 433b from getting caught when the blank sheet 1a is fed out. Also, the provision of the small-diameter second arc portion 433b-2 increases the number of meandering apexes and enhances the fragility of the fragile portion 433, making it easier to open the lid portion 12.

[0037] 9(d), which is a further modification of the first modification of FIG. 9(a), has a sawtooth-shaped meandering slit 533b formed by a plurality of slit portions 533a in the weak portion 533 between the first slit 131 and the second slit 132. However, in the meandering slit 533b of the fourth modification, the meandering pitch P51 is approximately the same length as the interval L11 between the first slit 131 and the second slit 132.

[0038] According to the fourth modified example, by making the serpentine pitch P51 shorter than that of the first modified example, the effect of improving productivity is limited, but the fragility of the fragile portion 533 is increased, making it easier to open the lid portion 12.

[0039] In the fifth modified example shown in FIG. 9(e), the plurality of slit portions 633a in the fragile portion 633 constitute a plurality of first arc slits 633b and second arc slits 633c as follows. The first arc slit 633b is a convex arc slit on one slit side (the second slit 132 in this modified example) of the first slit 131 and the second slit 132, in which the ends of a pair of slit portions 633a are connected to each other. The second arc slit 633c is a convex arc slit on the other slit side (the first slit 131 in this modified example) in which the ends of a pair of slit portions 633a are connected to each other. The fragile portion 633 is formed such that the first arc slits 633b and the second arc slits 633c, which are convex in opposite directions, are alternately arranged.

[0040] According to this fifth modification, it is possible to provide many weak points in the weak portion 633 with short intervals between the first slit 131 and the second slit 132 and the tops of the first arc-shaped slit 633b and the second arc-shaped slit 633c, and between these two arc-shaped slits. This increases the weakness of the weak portion 633, making it easier to open the lid portion 12. In this fifth modification, the distance between the two arc-shaped slits may be appropriately determined taking into consideration the material and thickness of the blank sheet, and may be, for example, 1 to 3 mm.

[0041] 9(f) is a further modification to the first modification of FIG. 9(a), in which the meandering apex of the sawtooth-shaped meandering slit 733b in the weak portion 733 is closer to the first slit 131 and the second slit 132 than in the first modification. Also, the meandering pitch P71 is longer than the distance L11 between the first slit 131 and the second slit 132, similar to the first modification.

[0042] According to this sixth modified example, the meandering pitch P71 is lengthened to improve productivity, while the apex of the meandering is brought closer to the first slit 131 and the second slit 132 to increase the fragility of the fragile portion 733, making it easier to open the lid portion 12.

[0043] Fig. 10 is a diagram showing a seventh modified example of a weakened shape formed by a plurality of slits in the weak portion of the hinge wall. This seventh modified example is obtained by adding some modifications to the weakened shape in the embodiment shown in Figs. 1 to 8. In Fig. 10, the same components as those in this embodiment are shown with the same reference numerals used in the description of the embodiment, and the following description of these components will be omitted.

[0044] The seventh modified example is the same as the above-mentioned embodiment in that a wavy meandering slit 833b consisting of a plurality of slit portions 133a, 833a is provided in the weak portion 833 between the first slit 131 and the second slit 132. However, in this modified example, the following two slit portions 833a among the plurality of slit portions 133a, 833a constituting the meandering slit 833b extend with a break at one point in the middle. One of these two slit portions 833a is the slit portion 833a that forms the uphill mountain-shaped portion on the left side in the figure, among the two mountain-shaped portions that protrude toward the second slit 132 side at the center of the meandering slit 833b. The other is the slit portion 833a that forms the downhill mountain-shaped portion on the right side in the figure, among the above two mountain-shaped portions. These two slit portions 833a each end at approximately the center of their extension, and this end serves as a connecting portion 833a-1 that connects the inner edges of the slit portions 833a with a very small width.

[0045] Furthermore, in this modification, in addition to the connecting portion 833a-1 in the above-mentioned two slit portions 833a, a similar connecting portion 833b-1 is provided at the top of a mountain shape in the center of the meandering slit 833b that protrudes toward the first slit 131. This central connecting portion 833b-1 is formed by separating the ends of two slit portions 133a that form a mountain shape protruding toward the first slit 131 by a very small width.

[0046] The above-mentioned connecting portions 833a-1, 833b-1 provided in the middle of the slit portion 833a and at the top of the meandering slit 833b are preferably broken when the lid is opened in order to fully utilize the buckling ability of the fragile portion 833. From this viewpoint, the width of each of the connecting portions 833a-1, 833b-1 is preferably 0.1 to 0.4 mm, and more preferably 0.1 to 0.3 mm.

[0047] According to the seventh modified example described above, the two connecting parts 833a-1 provided on the two slit parts 833a prevent the inner edge of the meandering slit 833b from lifting up. As a result, it is possible to prevent the edges of the meandering slit 833b from getting caught when the blank sheet 1a is fed out. Furthermore, in this modified example, the connecting part 833b-1 is also provided between the ends of the two slit parts 133a in the center of the meandering slit 833b, so that the inner edge of the meandering slit 833b is further prevented from lifting up. In other words, in this modified example, the central connecting part 833b-1 is provided, so that it is possible to further prevent the blank sheet 1a from getting caught when it is fed out.

[0048] Furthermore, the first slit and the second slit are not limited to the pair of linear slits exemplified in the above-described embodiment and the first to seventh modified examples, but may be various modified examples as described below.

[0049] Fig. 11 is a diagram showing eighth to tenth modified examples relating to the first slit and the second slit. In Fig. 11, the same components as those in the above-mentioned embodiment are shown with the same reference numerals used in the description of the embodiment, and the following description of those components will be omitted.

[0050] 11(a), the first slit 131 formed at the boundary 13a between the container-side rear wall 112c and the lid-side rear wall 122c of the pair of slits sandwiching the weak portion 933 of the hinge wall 93 is similar to that of the above-described embodiment. That is, the first slit 131 is a straight slit that extends linearly along the boundary 13a.

[0051] On the other hand, the second slit provided in the lid-side rear wall 122c with a fragile portion 933 sandwiched between it and the first slit 131 is a meandering second slit 931 as follows. The meandering second slit 931 is a slit that extends in a wavy meandering manner along the first slit 131 while repeatedly approaching and moving away from the first slit 131.

[0052] In this modification, the fragile portion 933 is formed with a meandering slit 933b having the same configuration as in the above embodiment. That is, the meandering slit 933b has a plurality of slit portions 133a, 933a connected at their adjacent ends, and meanders in a wavy manner between the first slit 131 and the meandering second slit 931. However, unlike the above embodiment, the meandering slit 933b has a connecting portion 933a-1, which will be described later. The meandering second slit 931 is formed so that the phase of the wave is shifted by a half wavelength from the phase of the wave in the meandering slit 933b of the fragile portion 933.

[0053] Furthermore, in this modification, a serpentine third slit 932 is provided in the container-side rear wall 112c on the opposite side of the first slit 131 from the serpentine second slit 931 and the fragile portion 933. The serpentine third slit 932 is a slit formed in the container-side rear wall 112c so as to extend along the first slit 131 while leaving a gap between the serpentine third slit 932 and the first slit 131. The serpentine third slit 932 extends in a wavy serpentine manner along the first slit 131 while repeatedly approaching and moving away from the first slit 131. Furthermore, the serpentine third slit 932 is formed so that the phase of the waves is the same as the phase of the waves in the serpentine slit 933b of the fragile portion 933.

[0054] Here, in this modification, the total length of the meandering slit 933b of the fragile portion 933 is shorter than the total length of any of the first slit 131, the meandering second slit 931, and the meandering third slit 932. This reduces the risk of tearing between the linear first slit 131 and the meandering slit 933b of the fragile portion 933. Strictly speaking, both ends of the linear first slit 131 are slightly upward cuts toward the fragile portion 933. If the meandering slit 933b of the fragile portion 933 is formed to have the same length as such a first slit 131, the both ends of the meandering slit 933b toward the first slit 131 are close to both ends of the first slit 131, and there is a risk of tearing. Therefore, by making the overall length of the meandering slit 933b of the fragile portion 933 shorter than that of the first slit 131, both ends of the meandering slit 933b are separated from both ends of the first slit 131, thereby reducing the risk of tearing. The meandering second slit 931 and the meandering third slit 932 are originally separated from both ends of the first slit 131 and also from both ends of the meandering slit 933b, and therefore are formed to have the same length as the first slit 131, which is longer than the meandering slit 933b.

[0055] In this modification, a plurality of joints 933a-1, 934 are formed in each of the meandering slit 933b, the meandering second slit 931, and the meandering third slit 932 of the fragile portion 933. The joints 933a-1 in the meandering slit 933b of the fragile portion 933 are formed in each of a pair of slit portions 933a that are separated from the center by one mountain on each side and form a downward slope toward the container-side rear wall 112c. The joints 933a-1 cause the pair of slit portions 933a to extend with a break at one point along the way, and the meandering slit 933b of the fragile portion 933 extends with a break at two points overall.

[0056] The connecting portions 934 in the meandering second slit 931 are formed at the apexes of the four valleys closest to the fragile portion 933. Due to the connecting portions 934, the meandering second slit 931 extends with four breaks in between.

[0057] Moreover, the connecting portions 934 in the meandering third slit 932 are formed in two locations corresponding to the two connecting portions 933a-1 in the meandering slit 933b of the fragile portion 933. Due to the connecting portions 934, the meandering third slit 932 also extends with two breaks in between.

[0058] In the eighth modified example described above, the second slit sandwiching the fragile portion 933 between itself and the first slit 131 is the meandering second slit 931. With this configuration, it is possible to increase the fragility of the fragile portion 933 compared to when the second slit is linear.

[0059] In this modification, the meandering second slits 931 are formed in a wave shape that is shifted by a half wavelength from the phase of the waves in the meandering slits 933b of the weak portion 933. With this configuration, a closest point where the apexes face each other is provided between the meandering slits 933b of the weak portion 933 and the meandering second slits 931, and the fragility of the weak portion 933 can be further increased.

[0060] In this modification, the serpentine third slit 932 is provided on the opposite side to the serpentine second slit 931 and the fragile portion 933 as viewed from the first slit 131. With this configuration, the fragility of the portion on the serpentine third slit 932 side is also increased, so that the fragile portion 933 can be made to buckle even more easily.

[0061] In this modification, the meandering third slit 932 is formed to have the same phase as the wave phase in the meandering slit 933b of the fragile portion 933. According to this configuration, the meandering third slit 932 is formed in a wave shape that is also shifted in phase by a half wavelength from the wave phase in the meandering second slit 931, and the fragility between them including the fragile portion 933 can be further increased, making the fragile portion 933 more likely to buckle.

[0062] In this modification, the meandering second slit 931 extends with the slits interrupted at four points along the way by connecting portions 934. This configuration can further reduce the possibility of the blank sheet 1a (FIG. 7) getting caught when it is fed out.

[0063] In this modification, the meandering third slit 932 extends with two breaks in between by connecting portions 934. This configuration also makes it possible to further prevent the blank sheet 1a (FIG. 7) from getting caught when it is fed out.

[0064] Next, in the ninth modified example shown in FIG. 11(b), the first slit 131, the meandering slit 933b of the fragile portion 933, and the meandering second slit 931 are all equivalent to those in the eighth modified example shown in FIG. 11(a). Although not shown in FIG. 11(b) to avoid complication, the meandering slit 933b of the fragile portion 933 and the meandering second slit 931 in this modified example also have the same connecting portions 933a-1 and 934 as those in FIG. 11(a). The entire length of the meandering slit 933b of the fragile portion 933 is shorter than the linear first slit 131 and the meandering second slit 931. On the other hand, in this modified example, a portion corresponding to the meandering third slit 932 in the eighth modified example is not provided. In this modified example, the following ruled lines 1031 are provided.

[0065] The crease 1031 is a linear crease extending along the boundary 13a at a position away from the boundary 13a on at least one of (in this modification, both) the container sidewall portion 112c and the lid sidewall portion 122c of the hinge wall 103. In this modification, two of the creases 1031 are formed at equal intervals on the container sidewall portion 112c, and one is formed on the lid sidewall portion 122c.

[0066] In the ninth modified example described above, the lines 1031 formed on the hinge wall 103 serve as a reinforcing structure that suppresses bending deformation of the hinge wall 103. This makes it difficult for the hinge wall 103 to bend when the lid is opened, improving ease of opening the lid.

[0067] In the tenth modified example shown in FIG. 11(c), the first slit 131 and the meandering second slit 931 are both equivalent to those in the eighth modified example shown in FIG. 11(a). Although not shown in FIG. 11(c) to avoid complication, the meandering second slit 931 in this modified example also has a joint 934 similar to that in FIG. 11(a). In addition, the entire length of the meandering slit 1133b of the fragile part 1133 is shorter than the linear first slit 131 and the meandering second slit 931. On the other hand, in this modified example, the fragile part 1133 is provided with a meandering slit 1133b similar to that of the above-mentioned embodiment, in which the joint 933a-1 is not formed as in the eighth and ninth modified examples. In addition, in this modified example, only one ruled line 1031 equivalent to that in the ninth modified example shown in FIG. 11(b) is formed in the container side wall part 112c.

[0068] In the tenth modified example described above, since the connecting portion 933a-1 is not formed in the serpentine slit 1133b of the weak portion 1133, the effect of preventing the blank sheet 1a (Figure 7) from getting caught when it is fed out is reduced, but the fragility of the weak portion 1133 can be increased.

[0069] Moreover, in this modified example, since there is only one line 1031, the effect of suppressing the bending of the hinge wall 113 is reduced compared to the above-mentioned ninth modified example, but it goes without saying that the effect of the single line 1031 can still be expected.

[0070] The above-described embodiment and the first to tenth modified examples are merely representative examples, and the packaging container is not limited to these embodiments. That is, a person skilled in the art can implement various modifications according to conventionally known knowledge.

[0071] For example, in the above-described embodiment and the first to tenth modified examples, a packaging container 1 that contains a product in a fast food restaurant or the like and is provided to a user is exemplified as an example of a packaging container. However, the packaging container is not limited to this, and may be used in restaurants other than fast food restaurants, or may be used in stores other than restaurants. The packaging container may be used in any specific place as long as it is an openable and closable container having a container part and a lid part.

[0072] In the above-described embodiment and the first to tenth modified examples, a packaging container 1 having a rectangular opening box-shaped container part 11 and a rectangular opening box-shaped lid part 12 is exemplified as an example of a packaging container. However, the packaging container is not limited to this, and may have a container part and a lid part in a polygonal opening box shape other than a rectangle, or may have a container part and a lid part in which the part other than the hinge wall is formed in a circular box shape or a dome shape. The specific external shape of the packaging container may be any shape as long as it is an openable and closable container having a container part and a lid part formed in an open box shape.

[0073] In the above-described embodiment and the first to tenth modified examples, an openable and closable packaging container 1 made of a sheet material such as paper is shown as an example of a packaging container. However, the packaging container is not limited to this, and may be made of a sheet material other than paper, such as a foldable thin plastic sheet, and the specific material of the packaging container is not important.

[0074] In the above-described embodiment, the third, seventh, and eighth to tenth modified examples, the slit parts 133a, 433a, 833a, and 933a constituting the wavy meandering slits 133b, 433b, 833b, 933b, and 1133b are exemplified as an example of the slit part provided in the weak part of the hinge wall. In the first, fourth, and sixth modified examples, the slit parts 233a, 533a, and 733a constituting the sawtooth meandering slits 233b, 533b, and 733b are exemplified. Furthermore, in the second and fifth modified examples, the slit part 333a is slanted in a straight line with the ends spaced apart from each other and adjacent to each other, and the slit part 633a is exemplified as the first arc slit 633b and the second arc slit 633c arranged apart from each other. However, the slit portion of the fragile portion is not limited to these, and may be, for example, a slit portion constituting an intermittent wavy or sawtooth meandering slit interrupted in a perforated manner, or a slit portion arranged parallel to each other. The presence or absence of connection of the slit portions in the fragile portion, the shape of the connection, and the direction and shape of each slit portion when arranged without connection can be set arbitrarily. However, as described above, by providing the slit portions 133a, 733a, 833a, 933a constituting the meandering slits 133b, . . . , 1133b, the fragile portions 133, . . . , 1133 can be easily buckled, and the lid portion 12 can be opened more easily. As described above, the wavy meandering slits 133b, 433b, 833b, 933b, 1133b can improve productivity, and the sawtooth meandering slits 233b, 533b, 733b can increase fragility and open the lid portion 12 more easily. As mentioned above, the adjacent slit portions 333a that are spaced apart from each other can improve productivity, and the first arc slit 633b and the second arc slit 633c increase fragility, making it easier to open the lid portion 12.

[0075] In the above-described embodiment, the first and sixth modified examples, the meandering slits 133b, 233b, 733b, and 833b are exemplified as an example of the meandering slit, in which the meandering pitches P11, P21, and P71 are longer than the interval L11 between the first slit 131 and the second slit 132. However, the meandering slit is not limited to this, and may be, for example, a meandering slit 533b in the fourth modified example, in which the meandering pitch P51 is approximately the same length as the interval L11, or may be shorter. However, as described above, by making the meandering pitches P11, P21, and P71 longer than the interval L11, the productivity in mass production can be improved.

[0076] In the seventh modified example described above, the fragile portion 833 is provided with joints 833a-1 and 833b-1 at three locations, namely, the middle of the two slit portions 833a in the meandering slit 833b and between the ends of the two central slit portions 133a. In the eighth and ninth modified examples described above, the fragile portion 933 is provided with joints 933a-1 at two locations, namely, the middle of the two slit portions 933a in the meandering slit 933b. However, the fragile portion is not limited to this, and each slit portion or the meandering slit may not have any joints, and each slit portion may extend without interruption, and the ends of the slit portions may all be connected to each other. Such weak portions are illustrated as weak portions 133, 233, 433, 533, 733, and 1133 in the embodiment shown in Figure 1 and in the first, third, fourth, sixth, and tenth variants shown in Figures 9(a), (c), (d), and (f) and Figure 11(c).

[0077] Even if a connecting portion is provided, the shape of the connecting portion is not limited to the seventh to ninth modified examples. The connecting portion may be provided in a slit portion of a meandering slit having a shape other than a wave shape, such as a sawtooth shape, or in a mountain-shaped apex. Alternatively, the connecting portion may be provided in the middle of the discontinuous slit portion 333a shown in FIG. 9(b), in the middle of the partially continuous slit portion 333a shown in FIG. 9(e), or in the apex of the first and second arc slits 633b and 633c. In addition, the connecting portion may not be provided in the apex between the slit portions of the meandering slit or arc slit, but may be provided only in the middle of the slit portion.

[0078] Furthermore, even if a connecting portion is provided in the middle of a slit portion, it can be arbitrarily set which of the multiple slit portions in the fragile portion the connecting portion is provided in. In other words, as long as a connecting portion is provided in at least one slit portion in the fragile portion such that the slit portion is interrupted at at least one point in the middle, the specific position or number of the slit portions where the connecting portion is provided does not matter. Furthermore, the specific positions or number of the connecting portions to be provided in the slit portions does not matter.

[0079] Furthermore, even when connecting portions are provided at the peaks of the mountain shapes of the meandering slits, the specific positions and number of the peaks at which the connecting portions are provided can be set arbitrarily.

[0080] In the above-described embodiment and the first to seventh modified examples, the first slit 131 and the second slit 132, both of which are continuous without interruption, are exemplified as examples of the first slit and the second slit, respectively. However, the first slit and the second slit are not limited to this, and one or more connecting parts may be provided midway through at least one of the first slit and the second slit.

[0081] In the above-described embodiment and the first to seventh modified examples, the first slit 131 and the second slit 132, both of which are formed in a straight line, are exemplified as examples of the first slit and the second slit, respectively. However, the first slit and the second slit are not limited to this. As long as the first slit is formed so as to extend along the boundary between the container side wall portion and the lid side wall portion, and the second slit is formed so as to extend along the first slit, the specific shape of each slit is not important.

[0082] In addition, in the eighth to tenth modified examples, a meandering second slit 931 is illustrated as an example of the second slit. However, the second slit is not limited to this, and may be linear like the second slit 132 shown in the above-described embodiment and the first to seventh modified examples, or may adopt any other shape. However, as described above, by providing the meandering second slit 931, the fragility of the fragile portion 133 can be increased.

[0083] In addition, in the eighth to tenth modified examples, as an example of the meandering second slit, the meandering second slit 931 is exemplified, which is wavy and whose wave phase is shifted by a half wavelength from the wave phase of the meandering slits 133b, 933b of the weak parts 933, 1133. However, the meandering second slit is not limited to this. First, the meandering shape may be any shape such as a sawtooth shape. In addition, the phase relationship with the meandering slit of the weak part may be the same phase, or the wave phase may be shifted by any shift amount other than a half wavelength. However, as described above, the meandering second slit 931, which is wavy and shifted by a half wavelength from the meandering slits 133b, 933b of the weak parts 933, 1133, can further increase the fragility of the weak parts 133, 1133.

[0084] In the eighth modified example, as an example of a hinge wall provided with a serpentine second slit, a hinge wall 93 provided with a serpentine second slit 931 and a serpentine third slit 932 is exemplified. However, the hinge wall is not limited thereto, and even if the serpentine second slit 931 is provided, the hinge wall may not be provided with a portion corresponding to the serpentine third slit 932, as exemplified in the ninth and tenth modified examples. However, as described above, by providing the serpentine third slit 932, the fragile portion 933 can be made more likely to buckle.

[0085] In the eighth modified example, as an example of the meandering third slit, a meandering third slit 932 is illustrated which is wavy and whose wave phase is the same as the wave phase of the meandering slit 933b of the fragile portion 933. However, the meandering third slit is not limited to this. First, the meandering shape may be any shape such as a sawtooth shape. In addition, the phase relationship with the fragile portion and the meandering slit may be such that the wave phase is shifted by any shift amount. However, as described above, the meandering third slit 932 which is wavy and in phase with the meandering slit 933b of the fragile portion 933 can make the fragile portion 933 more easily buckled.

[0086] In addition, in the eighth to tenth modified examples, as an example of the meandering second slit, a meandering second slit 931 in which the slit is interrupted at four points along the way by connecting parts 934 is exemplified. However, the meandering second slit is not limited to this, and may be a slit formed without interruption along the entire length. However, as described above, the meandering second slit 931 in which the slit is interrupted along the way can further reduce the possibility of the blank sheet 1a (FIG. 7) getting caught when being sent out. Even when the meandering second slit is interrupted along the way by providing connecting parts, the specific position and number of interrupted parts are not important as long as the slit is interrupted at least at one point along the way.

[0087] In the eighth modified example, as an example of the serpentine third slit, a serpentine third slit 932 in which the slit is interrupted at two points on the way by a connecting portion 934 is exemplified. However, the serpentine third slit is not limited to this, and may be a slit formed without interruption over the entire length. However, as described above, the serpentine third slit 932 in which the slit is interrupted on the way can further reduce the possibility of the blank sheet 1a (FIG. 7) getting caught when being sent out. Even if the serpentine third slit is interrupted on the way by providing a connecting portion, the specific position and number of interruptions are not important as long as the slit is interrupted at least at one point on the way.

[0088] In the ninth and tenth modified examples, the hinge walls 103, 113 are exemplified as an example of the hinge wall, in which at least one line 1031 is formed at a position away from the boundary 13a. However, the hinge wall is not limited to this, and no line may be formed at a position away from the boundary. However, as described above, by forming the line 1031, the hinge wall 103 is less likely to bend when the cover is opened, and the ease of opening can be improved. [Explanation of symbols]

[0089] 1 Packaging container 11 Container section 12 Lid 13,93,103,113 Hinge Wall 13a boundary 111 Bottom wall 112 Container side wall 112a Container side wall 112a-1 Container side lock piece 112b Container side front wall 112b-1 Container front fold-in piece 112c Container side back wall 112c-1 Container back side fold-in piece 121 Ceiling Wall 122 Lid side peripheral wall 122a Lid side wall 122a-1 Front lid fold-in piece 122b Lid side front wall 122b-1 Lid side lock piece 122c Lid side back wall 122c-1 Folding piece on the back side of the lid 131 First Slit 131a Lid side slit edge 131b Container side slit edge 132 Second Slit 133,233,333,433,533,633,733,833,933,1133 Weakened parts 133a, 233a, 333a, 433a, 533a, 633a, 733a, 833a.933a Slit section 133b,233b,433b,533b,733b,833b,933b,1133b Serpentine slit 931 Serpentine type second slit 932 Serpentine 3rd slit 1031 Ruled line 433b-1 First arc 433b-2 Second arc 633b First circular arc slit 633c Second circular arc slit 833a-1, 833b-1, 933a-1, 934 Joint D11 Lid opening direction D12 Buckling direction L11 Interval P11, P21, P51, P71 Serpentine pitch P31 Approach Pitch

Claims

1. A packaging container that can be opened and closed has a container portion and a lid portion each formed of a sheet material in an open box shape, and a container side wall portion that forms a part of the peripheral wall of the container portion and a lid side wall portion that forms a part of the peripheral wall of the lid portion are foldably connected to each other at their opening side edges to form a hinge wall, a first slit formed at a boundary between the container side wall portion and the lid side wall portion so as to extend along the boundary; a second slit formed in the hinge wall so as to extend along the first slit while being spaced from the first slit; a fragile portion that is more likely to buckle into the container due to stress when the lid is opened than other portions of the hinge wall by forming a plurality of slit portions that extend from one slit side to the other slit side between the first slit and the second slit so as not to contact both slits, along the boundary, and that is arranged along the boundary between the first slit and the second slit. A packaging container comprising:

2. The packaging container according to claim 1, characterized in that the multiple slit portions in the weak portion are arranged obliquely with respect to the boundary so that the ends of one side of the first slit and the second slit are adjacent to each other, and then the ends of the other side are adjacent to each other.

3. The packaging container according to claim 2, characterized in that adjacent ends of the multiple slit portions in the fragile portion are connected to form a meandering slit that meanders between the first slit and the second slit.

4. 3. The packaging container according to claim 2, wherein the meandering slit meanders in a sawtooth shape between the first slit and the second slit.

5. 3. The packaging container according to claim 2, wherein the meandering slit meanders in a wavy manner between the first slit and the second slit.

6. The packaging container according to claim 1, characterized in that at least one of the slit portions in the fragile portion extends with a break at at least one point along the way.

7. the first slit is a linear slit extending linearly along the boundary, 2. The packaging container according to claim 1, wherein the second slit is a meandering second slit that extends in a meandering manner along the first slit while repeatedly approaching and moving away from the first slit.

8. the plurality of slit portions in the weakened portion are disposed obliquely with respect to the boundary such that ends of one side of the first slit and the second slit are adjacent to each other, and then ends of the other side of the first slit and the second slit are adjacent to each other, and adjacent ends are connected to each other to form a meandering slit that meanders in a wavy manner between the first slit and the second slit, The packaging container described in claim 7, characterized in that the serpentine second slit is formed in a wavy manner along the first slit, and the phase of the wave extends at a half wavelength shift from the phase of the wave in the serpentine slit.

9. The packaging container described in claim 7, characterized in that it further comprises a serpentine third slit, which is a slit formed in the hinge wall on the opposite side of the first slit from the second slit and the weak portion, so as to extend along the first slit while leaving a gap between the first slit and the hinge wall, and which extends in a serpentine manner along the first slit while repeatedly approaching and moving away from the first slit.

10. the plurality of slit portions in the weakened portion are disposed obliquely with respect to the boundary such that ends of one side of the first slit and the second slit are adjacent to each other, and then ends of the other side of the first slit and the second slit are adjacent to each other, and adjacent ends are connected to each other to form a meandering slit that meanders in a wavy manner between the first slit and the second slit, The packaging container according to claim 9, characterized in that the serpentine third slit is wavy and meanders along the first slit, and the phase of the waves is formed to be the same as the phase of the waves in the serpentine slit.

11. 8. The packaging container according to claim 7, wherein the meandering second slit extends with a break at least at one point along the way.

12. The packaging container according to claim 9, wherein the meandering third slit extends with at least one break in the middle.

13. 2. The packaging container according to claim 1, wherein at least one crease extending along the boundary at a position away from the boundary is formed in at least one of the container side wall portion and the lid side wall portion of the hinge wall.

Images