Packing box

Abstract

To provide a packaging box that is easy to seal and has high resistance to breakage.SOLUTION: A packaging box 1 includes: a side surface part 2; a top surface part 4; and a bottom surface part 6. A separation line L1 between a top surface inner flap 4a and a top surface outer flap 4d of the top surface part 4 is shifted in a direction in which a width of the top surface inner flap 4a becomes narrower with respect to a folding line M1 extending in a same direction as the separation line L1, an end part of the separation line L1 on the side plates 2a and 2d is connected to a cutting line C1 extending from the end part of the folding line M1 toward a center of the top surface inner flap 4a at a position excluding both ends thereof.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a packaging box formed by assembling cardboard sheets or the like.

Background Art

[0002] Currently, as a packaging box for home delivery or online shopping, a low-profile A-type cardboard box may be used. However, such an A-type box cannot be manufactured in a single process of printing, punching, and pasting, and generally requires many processes, leading to cost increases. As a method for manufacturing a low-profile A-type box in a single process, a method of providing a slit without a groove between the inner flap and the outer flap on the top surface side or the bottom surface side is known.

[0003] For example, in the sheet for a box described in Patent Document 1, a pair of first slits extending inward in the left-right direction of the connection portion from both ends of the connection portion between the pair of upper inner flaps and the first side panel and the third side panel, and second slits extending from the tips of each pair of first slits inward in the left-right direction of the connection portion and toward the tip side in the extending direction of the pair of upper inner flaps are formed. The first slit is connected to a slit between flaps without a groove.

[0004] And the base end side end portion X defined by the side edge of the upper inner flap, the first slit, and the second slit is held in a state of being pushed into the inside of the lower portion of the first slit in the first side panel.

[0005] When the pair of upper outer flaps are bent inward and the tips of the pair of upper outer flaps are abutted against each other, both end portions in the width direction of the pair of upper outer flaps are slightly recessed downward. Thereby, the holding state of the pair of upper inner flaps by the pair of upper outer flaps is stabilized (see Patent Document 1).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] However, the packaging box described in Patent Document 1 lacks a groove between the flaps (see Figure 2), which causes the inner and outer flaps to interfere with each other during sealing, making it difficult to close the lid. In addition, the first and second slits are located at the corners of the packaging box, which makes it prone to tearing towards the body.

[0008] This invention has been made in view of these circumstances, and aims to provide a packaging box that is easy to seal and highly resistant to breakage. [Means for solving the problem]

[0009] To achieve the above objective, the present invention provides a packaging box comprising a side portion that forms a peripheral wall with a plurality of side plates, a top portion that is planar with a plurality of flaps connected to one end of the side portion, and a bottom portion that is planar with a plurality of flaps connected to the other end of the side portion, At least one of the separation lines between the inner flap and the outer flap of the top surface and the separation lines between the inner flap and the outer flap of the bottom surface is provided offset in a direction that narrows the width of the inner flap with respect to the folding curve between the side plates that extends in the same direction as the separation line, and the end of the separation line on the side surface is connected to a cut line that extends from the end of the folding curve toward the center of the inner flap, at a position excluding both ends of the cut line.

[0010] The present invention relates to a packaging box consisting of side panels, a top panel, and a bottom panel, which can store items inside. The separation line between the inner flap and the outer flap of the top panel (or bottom panel) is offset from the folding curve between the side panels in a direction that narrows the width of the inner flap. As a result, the inner flap and the outer flap do not come into contact with each other when sealing, the inner flap can be easily folded inward, and sealing is easy.

[0011] Furthermore, the end of the separation line on the side is connected (in a roughly T-shape) to a cut line that extends from the end of the fold curve toward the center of the inner flap, excluding both ends of the cut line. In this configuration, the force is distributed to both sides of the separation line, resulting in a packaging box with high resistance to breakage.

[0012] In the packaging box of the present invention, it is preferable that the cut line is a curve that extends from the folding curve onto the side plate adjacent to the inner flap and reaches the inner flap of the top surface.

[0013] With this configuration, the cut line forms a downward-convex curve that reaches from the side panel to the inner flap of the top when the packaging box is assembled. As a result, pressure cannot escape downwards, preventing the packaging box from tearing.

[0014] Furthermore, in the packaging box of the present invention, it is preferable that the packaging box is made of corrugated cardboard, and the offset of the separation line is half the width of the thickness of the corrugated cardboard.

[0015] The offset of the separation line relative to the fold line on the side should be half the width of the corrugated cardboard thickness (not necessarily the same width). This makes it easier to fold the inner flap when sealing. [Brief explanation of the drawing]

[0016] [Figure 1] This is a plan view of the corrugated cardboard used for packaging boxes. [Figure 2] This is a magnified view of the area surrounding the cutting line. [Figure 3A] This figure shows the top inner flap and the retaining clip in a bonded state. [Figure 3B] This diagram (on its side) shows the top flap and stopper in a bonded state. [Figure 4] This diagram shows the top inner flap folded down. [Figure 5] This is a perspective view showing the packaging box after assembly. [Figure 6]This is a view of the assembled packing box seen from the bottom side.

Embodiments for Carrying out the Invention

[0017] Hereinafter, referring to the drawings, a packing box according to an embodiment of the present invention will be described. The packing box 1 is a rectangular cardboard box (type A) and can store objects inside. Specifically, it is composed of four side faces 2 that form the peripheral wall, a planar top face 4, and a planar bottom face 6.

[0018] FIG. 1 shows the cardboard sheet 1x in the state before the assembly of the packing box 1. The packing box 1 is a packing box with a low height direction that is assembled by folding the cardboard sheet 1x. Hereinafter, referring to FIG. 1, the details of the cardboard sheet 1x will be described.

[0019] For the production of the cardboard sheet 1x, sheets are bonded using a bonding machine, and the horizontal grid lines (folding lines N1, N2) are processed. Next, the vertical grid lines (folding lines M1 to M4) are processed using a processing machine to form grooves (slits S1 to S3). Also, the upper part of the margin (margin 2e) is processed.

[0020] Finally, using a die, cut lines (separation lines L1 to L4) are made in the grooves, and further, the lower part of the margin is processed. In this way, by combining a die with a processing machine, the manufacturing cost can be suppressed compared to the conventional processing method that uses a plurality of processing machines.

[0021] The cardboard sheet 1x includes side plates 2a to 2d and a margin 2e that form the side face 2, inner top flaps 4a, 4c and outer top flaps 4b, 4d that form the top face 4, and inner bottom flaps 6a, 6c and outer bottom flaps 6b, 6d that form the bottom face 6.

[0022] The side panel 2a, which forms part of the peripheral wall, is connected to the top flap 4a of the top section 4 via a fold curve N1, and to the bottom flap 6a of the bottom section 6 via a fold curve N2. These fold curves N1 and N2 are lines that facilitate the folding of the corrugated cardboard 1x, and this is also true for the other fold curves described later. The size of the side panel 2a in the left-right direction is smaller than that of the side panels 2b and 2d described later (side panels 2a and 2c are the short sides).

[0023] The left end of side plate 2a is connected to side plate 2d via a bending curve M1. The right end of side plate 2a is connected to side plate 2b via a bending curve M2.

[0024] The inner top flap 4a is one of a pair of inner flaps that make up the top surface 4. The left end of the inner top flap 4a is connected to the outer top flap 4d via a separation line L1. The right end of the inner top flap 4a is connected to the outer top flap 4b via a separation line L2.

[0025] As shown in the figure, the separation line L1 between the inner top flap 4a and the outer top flap 4d of the top surface 4 is offset from the folding curve M1 in a direction that narrows the width (left-right direction) of the inner top flap 4a. Similarly, the separation line L2 between the inner top flap 4a and the outer top flap 4b of the top surface 4 is also offset from the folding curve M2 in a direction that narrows the width of the inner top flap 4a.

[0026] Because the width of the inner top flap 4a is made narrower than the width of the side panel 2a, the inner top flap 4a and the outer top flaps 4b and 4d do not come into contact with each other when sealing the packaging box 1, making them easy to fold inward.

[0027] As will be explained in more detail later, the inner top flap 4a has cut lines C1 and C2. Cut line C1 extends from the end of the fold curve M1 toward the center of the inner top flap 4a, and the end of the separation line L1 on the side portion 2 (side plate 2a) is connected at a position on cut line C1 (excluding both ends).

[0028] The cut line C2 extends from the end of the folding curve M2 toward the center of the top flap 4a, and the end of the separation line L2 on the side portion 2 (side plate 2a) is connected at a position on the cut line C2 (excluding both ends).

[0029] The bottom inner flap 6a is one of a pair of inner flaps that make up the bottom portion 6. The left end of the bottom inner flap 6a is connected to the bottom outer flap 6d via a slit S1. The right end of the bottom inner flap 6a is connected to the bottom outer flap 6b via a slit S2. Note that the spacing between slits S1, S2 and slit S3 (described later) is wider than that between the separation lines L1 and L3.

[0030] The side panel 2b is the long side, and the top outer flap 4b is connected to it via a folding curve N1, and the bottom outer flap 6b is connected to it via a folding curve N2. The right end of the side panel 2b is connected to the side panel 2c via a folding curve M3.

[0031] The top outer flap 4b is one of a pair of outer flaps that make up the top surface 4. The right end of the top outer flap 4b is connected to the top inner flap 4c via a separation line L3. The bottom outer flap 6b is one of a pair of outer flaps that make up the bottom surface 6. The right end of the bottom outer flap 6b is connected to the bottom inner flap 6c via a slit S3.

[0032] The side panel 2c is connected to the top inner flap 4c via a fold curve N1, and to the bottom inner flap 6c via a fold curve N2. The top inner flap 4c is one of a pair of inner flaps that make up the top section 4. The bottom inner flap 6c is one of a pair of inner flaps that make up the bottom section 6.

[0033] As shown in the figure, the separation line L3 between the outer top flap 4b and the inner top flap 4c is offset from the folding curve M3 of the side section 2 in a direction that narrows the width of the inner top flap 4c. The cut line C3 extends from the end of the folding curve M3 toward the center of the inner top flap 4c, and the end of the separation line L3 on the side section 2 (side plate 2c) is connected at a position on the cut line C3 (excluding both ends).

[0034] Side plate 2d is attached to the left end of side plate 2a via a fold curve M1. Side plate 2d is connected to the top outer flap 4d via a fold curve N1 and to the bottom outer flap 6d via a fold curve N2. The top outer flap 4d is one of a pair of outer flaps that make up the top section 4. The bottom outer flap 6d is one of a pair of outer flaps that make up the bottom section 6.

[0035] A stopper 2e is attached to the left end of the side panel 2d via a fold line M4. The position to which the stopper 2e is attached can be changed depending on the configuration of the corrugated cardboard 1x. That is, the stopper 2e only needs to be attached to the end of one of the combinations of side panels 2a to 2d located at both ends when the packaging box 1 is unfolded.

[0036] Furthermore, as shown in the figure, the separation line L4 between the stopper 2e and the top outer flap 4d is aligned with the fold curve M4 of the side section 2. The cut line C4 extends from the end of the fold curve M4 toward the center of the stopper 2e, and the end of the separation line L4 on the side section 2 (side plate 2d) is connected at a position on the cut line C4 (excluding both ends).

[0037] The bottom surface 6 may also be separated by separation lines similar to those used for the top surface 4. Specifically, the separation line separating the inner bottom flap 6a and the outer bottom flap 6d is provided by shifting it relative to the folding curve M1 in a direction that narrows the width (left-right direction) of the inner bottom flap 6a, and the separation line separating the inner bottom flap 6a and the outer bottom flap 6b is provided by shifting it relative to the folding curve M2 in a direction that narrows the width of the inner bottom flap 6a.

[0038] Similarly, the width (left-right direction) of the inner bottom flap 6c is offset in a direction that narrows relative to the folding curve M3. Each of these separation lines may be connected to a curved cut line similar to that of the top surface 4. The cut line only needs to be provided on either the top surface 4 or the bottom surface 6.

[0039] Figure 2 is an enlarged view of the area R surrounding the cutting line C1.

[0040] As shown in the figure, the separation line L1 is offset from the folding curve M1 in a direction that narrows the width of the inner top flap 4a. This offset width D is preferably about half the thickness of the corrugated cardboard (about 3.0 mm). This makes it even easier to fold the inner top flap 4a when sealing.

[0041] The cut line C1 is a curve that extends from the end of the folding curve M1 onto the side plate 2a adjacent to the top inner flap 4a, and further reaches the top inner flap 4a. If the cut line C1 were to include a straight line along the folding curve N1, the packaging box 1 might break downwards from near the intersection of the separation line L1 and the cut line C1 when assembled.

[0042] Furthermore, since the cut line C1 is connected to the separation line L1 in a roughly T-shape, the force is distributed to both sides of the separation line L1. When the packaging box 1 is assembled, the cut line C1 forms a downward-convex curve that reaches from the side section 2 to the inner flap 4a of the top section 4. As a result, the corner of the packaging box 1 including the cut line C1 (on the side of the top section 4 of the packaging box 1) does not allow pressure to escape downwards, improving resistance to rupture that tears downwards. The structure of the cut lines C2 to C4 is the same as that of the cut line C1.

[0043] Figures 3A and 3B show the state in which the side panels 2c and top inner flap 4c of the corrugated cardboard 1x are glued to the stopper 2e (before the completion of the packaging box 1).

[0044] In Figure 3A, the bottom surface 6 is facing downwards, so it can be seen that the cut lines C1 to C4 at the four corners are curves that are convex downwards. A slit S1 exists between the inner bottom flap 6a and the outer bottom flap 6d, and a folding curve M1 exists between the side plates 2a and 2d at a position where the slit S1 is extended upwards.

[0045] Furthermore, a separation line L1 exists between the inner top flap 4a and the outer top flap 4d, but it is slightly offset from the folding curve M1 and is not in a straight line.

[0046] Figure 3B shows the packaging box 1 (before completion) from Figure 3A laid on its side. Figure 3B shows that the spacing between the plates is wider at the slit S1 than at the separation line L1.

[0047] Figure 4 shows the state after folding the inner top flap 4a from the state shown in Figure 3A.

[0048] When the inner top flap 4a is folded inward, the cut lines C1 and C2 are slightly open, as shown in the figure. Also, since the inner top flap 4a is made to be slightly narrower in the width direction compared to the side plate 2a, the inner top flap 4a can be easily folded without coming into contact with the outer top flaps 4b and 4d.

[0049] On the other hand, the width of the top outer flap 4b is longer in the lateral direction compared to the side plate 2b. As a result, both ends of the top outer flap 4b protrude slightly outward from the positions of the fold curves M2 and M3. Similarly, both ends of the top outer flap 4d protrude slightly outward from the fold curves M1 and M4.

[0050] Figure 5 is a perspective view showing the assembled packaging box 1.

[0051] This is the state where the inner top flaps 4a and 4c are folded inward, and the outer top flaps 4b and 4d are also folded inward to form a lid. In this state, the cut lines C1 to C4 are located at the four corners of the packaging box 1 (above the side panels 2a to 2d), but the ends of the outer top flaps 4b and 4d protrude outward, so the cut lines C1 to C4 are hardly visible from the outside.

[0052] The cut lines C1 to C4 have the effect of distributing pressure, thus reliably preventing tearing that would occur from the corners (on the top surface 4 side of the packaging box 1) including the cut lines C1 to C4 downwards. In this way, the packaging box 1 has a structure to prevent tearing, but its appearance as a box is not compromised.

[0053] Figure 6 is a perspective view of the assembled packaging box 1, seen from the bottom 6 side.

[0054] As shown in the diagram, the cut lines C1 and C2 can be seen from the bottom surface 6, and the ends of the top outer flaps 4b and 4d protrude outwards. The part slightly visible from the cut lines C1 and C2 is the corner of the top inner flap 4a.

[0055] When using packaging box 1, secure the adjacent parts of the bottom outer flap 6b and bottom outer flap 6d with tape or the like, and fill the inside of packaging box 1 with goods. Finally, fold in the top inner flap 4a and top inner flap 4c, and fold in the top outer flap 4b and top outer flap 4d, and secure the adjacent parts with tape or the like.

[0056] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from the spirit of the invention.

[0057] In the above embodiment, the cut lines C1 to C4 were provided at the four corners of the packaging box 1, but it is not necessary to align them all; for example, two lines could be provided at diagonal positions. Furthermore, although the packaging box 1 in the above embodiment was a box with a relatively low height, the present invention can be applied to various packaging boxes, such as cube-shaped boxes. [Explanation of Symbols]

[0058] 1...Packaging box, 1x...Corrugated cardboard, 2...Side section, 2a~2d...Side panel, 2e...Fastener, 4...Top section, 4a,4c...Inner top flap, 4b,4d...Outer top flap, 6...Bottom section, 6a,6c...Inner bottom flap, 6b,6d...Outer bottom flap, C1~C4...Cutting line, L1~L4...Separation line, M1~M4,N1,N2...Folding curve, S1~S4...Slit.

Claims

1. A packaging box comprising a side section that forms a peripheral wall with multiple side plates, a top section that is flat due to multiple flaps connected to one end of the side section, and a bottom section that is flat due to multiple flaps connected to the other end of the side section, At least one of the separation lines between the inner flap and the outer flap of the top surface and the separation lines between the inner flap and the outer flap of the bottom surface is provided offset in a direction that narrows the width of the inner flap with respect to the folding curve between the side plates that extends in the same direction as the separation line. The packaging box is characterized in that the end of the separation line on the side portion is connected to a cut line extending from the end of the folding curve toward the center of the inner flap, at a position excluding both ends of the cut line.

2. In the packaging box according to claim 1, The packaging box is characterized in that the cut line is a curve that extends from the folding curve onto the side plate adjacent to the inner flap and reaches the inner flap of the top surface.

3. In the packaging box according to claim 1 or 2, The aforementioned packaging box is made of corrugated cardboard. A packaging box characterized in that the offset of the separation line is half the width of the thickness of the corrugated cardboard.

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