Protective sheet and packaging container

Abstract

To provide a protective sheet that eliminates the need for cushioning material. [Solution] The protective sheet is made of paper. The retaining sheet is divided into multiple polygonal regions that are arranged without gaps in a plan view. At the boundary between each of the multiple polygonal regions, a first polygonal region and each of the multiple second polygonal regions surrounding the first polygonal region, a cut is formed so that the first polygonal region is not separated from any of the multiple second polygonal regions. The cut penetrates the retaining sheet along the thickness direction of the retaining sheet.

Description

Technical Field

[0001] The present invention relates to a protective sheet and a packaging container.

Background Art

[0002] In Non-Patent Document 1 (Notosiki Co., Ltd., "How to Use Packaging Materials", Internet <URL:https: / / www.notosiki.co.jp / konpou / contents / guide / use.html>), it is disclosed that by disposing a cushioning material in a packaging container (corrugated box), the contents are prevented from moving within the packaging container or the impact applied to the contents is mitigated.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Non-Patent Document 1, a cushioning material is separately required to protect the contents of the packaging container. The present disclosure provides a protective sheet that can eliminate the need for a cushioning material.

Means for Solving the Problems

[0005] The protective sheet of the present invention is made of paper. In a plan view, the retaining sheet is divided into a plurality of polygonal regions that are arranged without gaps. At the boundary between each of the plurality of polygonal regions, a first polygonal region and a plurality of second polygonal regions surrounding the first polygonal region, a notch is formed so that the first polygonal region is not separated from any of the second polygonal regions. The notch penetrates the retaining sheet along the thickness direction of the retaining sheet. [Effects of the Invention]

[0006] According to the protective sheet of the present invention, cushioning material can be eliminated. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view of packaging container 100A. [Figure 2] This is an unfolded view of packaging container 100A. [Figure 3] This is a plan view of the retaining sheet 28. [Figure 4] This is a cross-sectional view taken at line IV-IV in Figure 3. [Figure 5] This is a disassembled perspective view of packaging container 100B. [Modes for carrying out the invention]

[0008] The embodiments of the present invention will be described in detail with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions will not be repeated.

[0009] (First Embodiment) A packaging container according to the first embodiment will be described. The packaging container according to the first embodiment will be referred to as packaging container 100A.

[0010] <Composition of Packaging Container 100A> The following describes the configuration of packaging container 100A.

[0011] Figure 1 is a perspective view of the packaging container 100A. As shown in Figure 1, the packaging container 100A has a box body 10. The box body 10 has a bottom wall 11, side walls 12, 13, 14 and 15, and a top wall 16. In plan view, the box body 10 is rectangular. Side walls 12 and 13 are spaced apart and facing each other in a first direction DR1. Side walls 14 and 15 are spaced apart and facing each other in a second direction DR2. The second direction DR2 is perpendicular to the first direction DR1.

[0012] Figure 2 is an unfolded view of the packaging container 100A. As shown in Figure 2, the box body 10 is assembled from sheet members 20. The sheet member 20 has a bottom wall portion 21, a side wall portion 22, a side wall portion 23, a side wall portion 24, a side wall portion 25, and a top wall portion 26.

[0013] The bottom wall portion 21 is rectangular in plan view. The bottom wall portion 21 has sides 21a, 21b, 21c, and 21d. Sides 21a, 21b, 21c, and 21d define the bottom wall portion 21. Sides 21a and 21b extend along the first direction DR1. Sides 21c and 21d extend along the second direction DR2.

[0014] The side wall portion 22 has a first portion 22a and a second portion 22b. The first portion 22a and the second portion 22b are rectangular in plan view. The first portion 22a has sides 22aa, 22ab, 22ac, and 22ad. Sides 22aa and 22ab extend along the first direction DR1. Side 22aa is common with side 21a. That is, side 22aa (side 21a) forms the boundary between the first portion 22a and the bottom wall portion 21. Side 22ab forms the boundary between the first portion 22a and the second portion 22b. Sides 22ac and 22ad extend along the second direction DR2. The side wall portion 22 further has a third portion 22c and a fourth portion 22d. The third portion 22c and the fourth portion 22d are rectangular in plan view. Edge 22ac forms the boundary between the first portion 22a and the third portion 22c, and edge 22ad forms the boundary between the first portion 22a and the fourth portion 22d. A notch 22da is formed in the fourth portion 22d.

[0015] The side wall portion 23 has a first portion 23a and a second portion 23b. The first portion 23a and the second portion 23b are rectangular in plan view. The first portion 23a has sides 23aa, 23ab, 23ac, and 23ad. Sides 23aa and 23ab extend along the first direction DR1. Side 23aa is common with side 21b. That is, side 23aa (side 21b) forms the boundary between the first portion 23a and the bottom wall portion 21. Side 23ab forms the boundary between the first portion 23a and the second portion 23b. Sides 23ac and 23ad extend along the second direction DR2. The side wall portion 23 further has a third portion 23c and a fourth portion 23d. The third portion 23c and the fourth portion 23d are rectangular in plan view. Edge 23ac forms the boundary between the first portion 23a and the third portion 23c, and edge 23ad forms the boundary between the first portion 23a and the fourth portion 23d. A notch 23da is formed in the fourth portion 23d.

[0016] The side wall portion 24 is rectangular in plan view. The side wall portion 24 has sides 24a and 24b. The sides 24a and 24b extend along the second direction DR2. The side 24a is common with the side 21c. That is, the side 24a (side 21c) forms the boundary between the bottom wall portion 21 and the side wall portion 24.

[0017] The side wall portion 25 is rectangular in plan view. The side wall portion 25 has sides 25a and 25b. The sides 25a and 25b extend along the second direction DR2. The side 25a is common with the side 21d. That is, the side 25a (side 21d) forms the boundary between the bottom wall portion 21 and the side wall portion 25.

[0018] The upper wall portion 26 is rectangular in plan view. The upper wall portion 26 has sides 26a and 26b. The sides 26a and 26b extend along the second direction DR2. The side 26a is common with the side 24b. That is, the side 26a (side 24b) forms the boundary between the side wall portion 24 and the upper wall portion 26. The upper wall portion 26 has an insertion portion 26c. The insertion portion 26c is provided on the side 26b. The insertion portion 26c protrudes from the side 26b along the first direction DR1.

[0019] The sheet member 20 further has a side wall portion 27, a holding sheet 28, a side wall portion 29, a side wall portion 30, and a side wall portion 31.

[0020] The side wall portion 27 is rectangular in plan view. The side wall portion 27 has sides 27a and 27b. The sides 27a and 27b extend along the second direction DR2. The side 27a is common with the side 25b. That is, the side 27a (side 25b) forms the boundary between the side wall portion 25 and the side wall portion 27. A notch 27c is formed at the boundary between the side wall portion 25 and the side wall portion 27.

[0021] The holding sheet 28 is rectangular in plan view. The holding sheet 28 has sides 28a, 28b, 28c, and 28d. Sides 28a and 28b extend along the second direction DR2. Side 28a is common with side 27b. That is, side 28a (side 27b) forms the boundary between the side wall portion 27 and the holding sheet 28. Sides 28c and 28d extend along the first direction DR1.

[0022] The side wall portion 29 is continuous with the holding sheet 28, and side 28b forms the boundary between the side wall portion 29 and the holding sheet 28. The side wall portion 30 is continuous with the holding sheet 28, and side 28c forms the boundary between the side wall portion 30 and the holding sheet 28. The side wall portion 31 is continuous with the holding sheet 28, and side 28d forms the boundary between the side wall portion 31 and the holding sheet 28. The side wall portions 29, 30, and 31 are rectangular in plan view.

[0023] In the assembly of the sheet member 20, first, the side wall portion 22 is bent along the boundary between the bottom wall portion 21 and the side wall portion 22, and the side wall portion 23 is bent along the boundary between the bottom wall portion 21 and the side wall portion 23. Thereafter, the second portion 22b is bent along the boundary with the first portion 22a, and the second portion 23b is bent along the boundary with the first portion 23a. Second, the third portion 22c is bent along the boundary with the first portion 22a, and the third portion 23c is bent along the boundary with the first portion 23a. Third, the fourth portion 22d is bent along the boundary with the first portion 22a, and the fourth portion 23d is bent along the boundary with the first portion 23a. At this time, the cut 22da and the cut 23da are locked to each other.

[0024] Fourth, the contents of the packaging container 100A (not shown) are placed on the bottom wall portion 21. Fifth, the side walls 27, 29, 30, and 31 are folded along the boundary with the retaining sheet 28. Fifth, the side wall portion 25 is folded along the boundary with the bottom wall portion 21. Sixth, the side wall portion 27 is folded along the boundary with the side wall portion 25. As a result, the contents of the packaging container 100A are held in place, sandwiched between the bottom wall portion 21 and the retaining sheet 28. At this time, the third portions 22c and 23c are sandwiched between the side walls 25 and 27. Furthermore, at this time, the contents of the packaging container 100A are held between the retaining sheet 28 and the bottom wall portion 21. Seventh, the side wall portion 24 is folded along the boundary with the bottom wall portion 21, and the top wall portion 26 is folded along the boundary with the side wall portion 24. Eighth, the insertion portion 26c is bent along the edge 26b and inserted into the notch 27c. This completes the assembly of the sheet member 20.

[0025] In the assembled state of the sheet member 20, the bottom wall portion 21 and the retaining sheet 28 form the bottom wall 11, the fourth portion 22d, the fourth portion 23d, the side wall portion 24 and the side wall portion 29 form the side wall 12, the third portion 22c, the third portion 23c, the side wall portion 25 and the side wall portion 27 form the side wall 13, the side wall portion 22 and the side wall portion 30 form the side wall 14, the side wall portion 23 and the side wall portion 31 form the side wall 15, and the top wall portion 26 form the top wall 16.

[0026] Figure 3 is a plan view of the retaining sheet 28. As shown in Figure 3, the retaining sheet 28 is divided into multiple polygonal regions 40 in a plan view. Each of the multiple polygonal regions 40 is congruent. The multiple polygonal regions 40 are arranged without gaps. In the illustrated example, the shape of the polygonal region 40 is an equilateral triangle.

[0027] Let any one of the multiple polygonal regions 40 be polygonal region 40A. Let the multiple polygonal regions 40 surrounding polygonal region 40A be multiple polygonal regions 40B. At the boundary between polygonal region 40A and each of the multiple polygonal regions 40B, a notch 41 is formed so that polygonal region 40A is not separated from any of the multiple polygonal regions 40B. More specifically, each of the multiple polygonal regions 40 has vertices 40a, 40b, and 40c, and is surrounded by multiple notches 41 (notches 41a, notches 41b, and notches 41c). Notch 41a extends from vertex 40a toward vertex 40b, but does not reach vertex 40b. Similarly, notch 41b extends from vertex 40b toward vertex 40c but does not reach vertex 40c, and notch 41c extends from vertex 40c toward vertex 40a but does not reach vertex 40a.

[0028] Let length L1 be the length of one side of each of the multiple polygonal regions 40. Let length L2 be the length of the cut 41. Length L2 is, for example, 0.6 to 0.9 times length L1. Length L2 may also be 0.7 to 0.8 times length L1.

[0029] The retaining sheet 28 (sheet member 20) is made of paper. Figure 4 is a cross-sectional view taken along line IV-IV in Figure 3. As shown in Figure 4, the retaining sheet 28 (sheet member 20) is corrugated cardboard 50 having a front liner 51, a back liner 52, and a core 53. The front liner 51 and the back liner 52 form the front and back surfaces of the corrugated cardboard 50, respectively. The grade of the front liner 51 and the back liner 52 are, for example, K6 or a grade with higher strength than K6. The grade of the front liner 51 may be the same as or different from the grade of the back liner 52. The core 53 is positioned between the front liner 51 and the back liner 52 and is sandwiched between them. In cross-sectional view, the core 53 has a wavy shape. The thickness of the core 53, that is, the wave height of the core 53 in a cross-sectional view, is, for example, 3 mm or less (B-flute or core with a lower B-flute).

[0030] <Effects of Packaging Container 100A> The effects of packaging container 100A are explained below.

[0031] If the packaging container 100A does not have a retaining sheet 28, cushioning material is placed in the internal space of the box 10 to prevent the contents from moving inside the box 10 or to absorb impacts to the contents, thereby protecting the contents. However, in this case, cushioning material will be required separately.

[0032] However, the packaging container 100A has a retaining sheet 28, and the contents are held in place by being sandwiched between the retaining sheet 28 and the bottom wall 21. The retaining sheet 28 is divided into a plurality of polygonal regions 40, and notches 41 are formed at the boundary between each of the plurality of polygonal regions 40A and the plurality of polygonal regions 40B so that the polygonal region 40A is not separated from any of the plurality of polygonal regions 40B. Therefore, when the contents are sandwiched between the retaining sheet 28 and the bottom wall 21, it can be deformed to conform to the shape of the contents. As a result, with the packaging container 100A, there is no need to use cushioning material separately.

[0033] Furthermore, if the retaining sheet 28 is made of corrugated cardboard 50, and the grade of the outer liner 51 and the inner liner 52 are K6 or a grade with higher strength than K6, and the thickness of the core 53 is 3 mm or less, the retaining sheet 28 will be more easily deformed to conform to the shape of the contents, and the advancement of the cut 41 and subsequent damage to the retaining sheet 28 will be suppressed. If the length L2 is 0.6 times or more and 0.9 times or less of the length L1, the advancement of the cut 41 and subsequent damage to the retaining sheet 28 when the retaining sheet 28 deforms to conform to the shape of the contents will be suppressed.

[0034] <Variation> The following describes a modified version of the retaining sheet 28.

[0035] In the above example, we described a case where each of the multiple polygonal regions 40 is a triangle (equilateral triangle), but each of the multiple polygonal regions 40 does not have to be an equilateral triangle (regular polygon). Each of the multiple polygonal regions 40 can be any polygon that can be arranged without gaps, for example, a quadrilateral (rectangle, square, parallelogram, rhombus) or a hexagon (regular hexagon).

[0036] (Second Embodiment) A packaging container according to the second embodiment will be described, with the packaging container according to the second embodiment referred to as packaging container 100B. Here, the differences from packaging container 100A will be mainly explained, and redundant explanations will not be repeated.

[0037] Figure 5 is an exploded perspective view of the packaging container 100B. As shown in Figure 5, the packaging container 100B, like the packaging container 100A, has a box body 10 made by assembling sheet members 20. However, in the packaging container 100B, the retaining sheet 28 is separated from the sheet members 20, i.e., the box body 10. In this respect, the packaging container 100B differs from the packaging container 100A. In the packaging container 100B, the retaining sheet 28 is attached to the box body 10 with the contents sandwiched between it and the bottom wall 21, so that the contents can be protected without using cushioning material, just like the packaging container 100A.

[0038] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the embodiments described above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0039] 100A Packaging container, 100B Packing container, 10 Box body, 11 Bottom wall, 12, 13, 14, 15 Side walls, 16 Top wall, 20 Sheet member, 21 Bottom wall section, 21a, 21b, 21c, 21d edges, 22 Side wall section, 22a 1st part, 22aa, 22ab, 22ac, 22ad edges, 22b 2nd part, 22c 3rd part, 22d 4th part, 23 Side wall section, 23a 1st part, 23aa, 23ab, 23ac, 23ad edges, 23b 2nd part, 23c 3rd part, 23d 4th part, 24 Side wall section, 24a, 24b edges, 25 Side wall section, 25a, 25b edges, 26 Top wall section, 26a edge, 26b edge, 26c Insertion section, 27 side wall section, 27a side, 27b side, 28 holding sheet, 28a, 28b, 28c, 28d sides, 29, 30, 31 side wall section, 40, 40A, 40B polygonal region, 40a, 40b, 40c vertices, 50 corrugated cardboard, 51 front liner, 52 back liner, 53 core, DR1 first direction, DR2 second direction, L1, L2 length.

Claims

1. A paper-based retaining sheet, The retaining sheet is divided into multiple polygonal regions that are arranged without gaps in a plan view. In the boundary between the first polygonal region among the plurality of polygonal regions and each of the plurality of second polygonal regions surrounding the first polygonal region, a notch is formed so that the first polygonal region is not separated from any of the plurality of second polygonal regions. The aforementioned cut penetrates the retaining sheet along the thickness direction of the retaining sheet. The aforementioned multiple polygonal regions are multiple triangular regions, Each of the aforementioned triangular regions has a first vertex, a second vertex, and a third vertex. The cuts include a first cut extending from the first vertex toward the second vertex along the first edge connecting the first vertex and the second vertex, a second cut extending from the second vertex toward the third vertex along the second edge connecting the second vertex and the third vertex, and a third cut extending from the third vertex toward the first vertex along the third edge connecting the third vertex and the first vertex. The length of the cut is 0.6 times or more and 0.9 times or less the length of one side of the plurality of triangular regions. A retaining sheet in which the aforementioned cuts are not formed in the first side portion located between the tip of the first cut and the second vertex, the second side portion located between the tip of the second cut and the third vertex, and the third side portion located between the tip of the third cut and the first vertex.

2. The aforementioned paper is corrugated cardboard having a front liner, a back liner, and a core disposed between the front liner and the back liner. The grade of the outer liner and the grade of the inner liner are K6 or a grade with higher strength than K6. The retaining sheet according to claim 1, wherein the thickness of the core is 3 mm or less.

3. A packaging container, The box and, A packaging container comprising the retaining sheet according to claim 1 or claim 2.

4. The aforementioned box is made by assembling sheet members, The packaging container according to claim 3, wherein the retaining sheet forms part of the sheet member.

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