Packaging material

Abstract

To improve workability at the time of packaging in a packaging material capable of adjusting thickness.SOLUTION: The packaging material 10 includes a pair of inner flaps 12 each folded back along one fold line 16a along an article G on a bottom plate 11, a pair of side plates 13 each folded to cover a space S between the bottom plate 11 and the inner flap 12, and a pair of outer flaps 14 folded to overlap on the inner flaps 12. On both sides of the inner flap 12 in the second direction Y, by a folding line 17a provided so as to extend along the first direction X, a flexible part 17a which can be bent by the contact of the side plate 13 is formed outside the folding line 12d.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to packaging materials. [Background technology]

[0002] Patent Document 1 discloses a packaging material that can be dropped into a post. This packaging material includes a rectangular bottom plate, a pair of inner flaps protruding from opposing edges of the bottom plate, and a pair of outer flaps protruding from other opposing edges of the bottom plate. Patent Document 1 also discloses a packaging material in which the inner and outer flaps each have multiple thickness-adjusting lines to package items of different thicknesses with as few gaps as possible. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7006224 Summary of the Invention [Problem to be solved by the invention]

[0004] In the latter packaging material described in Patent Document 1, the thickness of the packaged product can be adjusted by folding the flap along one of a plurality of thickness-adjusting lines, but the adjustment can only be made in stages. Also, when packaging an item, it is easy to make the mistake of folding along the wrong thickness-adjusting line, so there is room for improvement in terms of workability.

[0005] An object of the present invention is to improve workability during packaging using a packaging material that allows thickness adjustment. [Means for solving the problem]

[0006] The packaging material of the present invention comprises a bottom plate, a pair of inner flaps connected to both ends of the bottom plate in a first direction and each folded along a single first fold line so as to fit over an item on the bottom plate, a pair of side plates connected to both ends of the bottom plate in a second direction intersecting the first direction and each folded so as to cover a gap between the bottom plate and the inner flaps, and a pair of outer flaps connected to the tips of the pair of side plates and each folded so as to overlap the inner flaps.

[0007] One aspect of the present invention provides a packaging material in which a second fold line is formed on both sides of the inner flap in the second direction, extending along the first direction, and a flexible portion is formed outside the second fold line, which can bend when the side panel abuts against the second fold line. Another aspect of the present invention provides a packaging material, wherein both side edges of the inner flap in the second direction are inclined toward the center in the second direction from a base end connected to the bottom plate to a tip end.

[0008] In these embodiments, a pair of inner flaps connected to the bottom plate are each folded back along a single first fold line to fit the article on the bottom plate, and the gap between the bottom plate and the inner flaps is each covered by the side plate. In other words, there is no need to change the folding position of the inner flaps depending on the thickness of the article to be packaged. Furthermore, simply folding the inner flaps back against the bottom plate to fit the article allows for continuous adjustment. This configuration eliminates the possibility of incorrect folding, improving the workability when packaging articles.

[0009] In one embodiment of the packaging material, a flexible portion is formed on the outer side of the second fold line of the inner flap, which can bend when the side panel abuts against it. This allows the flexible portion to be positioned closely to the inner flap depending on the item to be accommodated, preventing the item from moving inside and allowing the item to be packaged in a stable state.

[0010] In another embodiment of the packaging material, both side edges of the inner flap are inclined toward the center from the base end connected to the bottom plate toward the tip, thereby preventing the side plates that move in conjunction with the outer flaps from getting caught on the side edges of the inner flap and interfering with the operation when the pair of outer flaps are squeezed toward the center in the second direction. [Effects of the Invention]

[0011] The present invention can improve workability during packaging using a packaging material that allows thickness adjustment. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view of a thin article packaged in a packaging material according to an embodiment of the present invention; [Figure 2] Cross-sectional view of line II-II in Figure 1. [Figure 3] FIG. 10 is a perspective view of a thick article wrapped in packaging material. [Figure 4] Cross-sectional view of line IV-IV in Figure 3. [Figure 5] An exploded view of the packaging material before use. [Figure 6] FIG. 2 is a cross-sectional view showing the configuration of a cardboard sheet. [Figure 7] FIG. [Figure 8] 10A and 10B are perspective views showing another packaging process using a packaging material. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] 1 to 4, a packaging material 10 according to an embodiment of the present invention is a post-in case that can be posted in a post.

[0015] The X direction, Y direction, and Z direction in the accompanying drawings respectively represent the length direction (front-rear direction), width direction (left-right direction), and thickness direction (height direction) of the packaging material 10. The length direction (X direction) is the first direction of the present invention, and the width direction (Y direction) is the second direction of the present invention. This concept of directions is merely an example and can be changed as appropriate depending on the posture of the packaging material 10, etc.

[0016] The length, width, and thickness of the packaging material 10 used as a post-in case are determined by specifications. The maximum thickness may vary depending on the delivery company, and is up to 30 mm.

[0017] 1 to 4, packaging material 10 includes a bottom plate 11, a pair of inner flaps 12, a pair of side plates 13, and a pair of outer flaps 14. Packaging material 10 of this embodiment can seamlessly package items G of different thicknesses within a range from the minimum thickness (e.g., 10 mm) shown in Figures 1 and 2 to the maximum thickness (e.g., 30 mm) shown in Figures 3 and 4. The maximum thickness shown in Figures 3 and 4 is the same as the largest thickness defined by the specifications.

[0018] 5 and 6, the packaging material 10 before use is a so-called "rubber type" that can be folded at predetermined locations to package an item G. The packaging material 10 is formed by punching out a paper corrugated cardboard sheet 1 having a corrugated medium 4 disposed between a front liner 2 and a back liner 3 using a well-known paper container punching device. The thickness of the cardboard sheet 1 from the outer surface of the front liner 2 to the outer surface of the back liner 3 is preferably 0.5 mm or more and 3.5 mm or less. However, the packaging material 10 may also be formed from a single layer of cardboard with a thickness of 0.1 mm or more and 1.0 mm or less.

[0019] The areas shown by dashed lines in Figure 5 are general-purpose creases formed by scoring from the back liner 3 side to compress the thickness. The areas shown by solid lines in Figure 5 are cutting lines or shape lines (edges) formed by cutting with a blade. The areas hatched upward to the left in Figure 5 are corrugated collapsed areas where the core 4 is crushed and the thickness of the cardboard sheet 1 is compressed.

[0020] 1 to 4, the bottom plate 11 is rectangular and extends along the XY plane. The length and width of the bottom plate 11 are set within the dimensions defined by the specifications, for example, the length is 276 mm and the width is 280 mm. However, the bottom plate 11 may also be octagonal with chamfered corners, and the length and width dimensions can be changed as needed as long as they are within the dimensions defined by the specifications.

[0021] The pair of inner flaps 12 are connected to both ends of the bottom plate 11 in the longitudinal direction via folding portions 16. The inner flaps 12 are folded back above the bottom plate 11 so as to fit the article G placed on the bottom plate 11. The pair of inner flaps 12 each have the same overall length from a base end 12a connected to the bottom plate 11 to a tip end 12b, and are set to dimensions that allow them to overlap each other in the maximum thickness packaging state shown in Figures 3 and 4.

[0022] 5, the pair of inner flaps 12 are connected to the top and bottom of the bottom plate 11 via a single fold line (first fold line) 16a that forms the fold portion 16. The fold line 16a is formed by a general-purpose crease.

[0023] 1 to 4, the pair of side panels 13 are connected to both ends of the bottom panel 11 in the width direction via bent portions 17. The side panels 13 are bent upward relative to the bottom panel 11 to cover the gaps S formed on both sides in the width direction between the bottom panel 11 and the inner flaps 12. The thickness dimension of the side panels 13 is equal to or less than the maximum thickness, e.g., 26 mm. Here, the thickness dimension of the side panels 13 (height length H) refers to the distance along the surface of the side panels 13 in the thickness direction. However, the dimensions of the side panels 13 vary depending on the thickness of the cardboard sheet 1, and can be changed as needed as long as they are equal to or less than the maximum thickness.

[0024] 5, the pair of side panels 13 are connected to the left and right of the bottom panel 11 via fold lines 17a that form the bent portion 17. The fold lines 17a are formed by lead creases, which are general-purpose creases with multiple cutting lines spaced apart to make them difficult to break. Here, the "difficult-to-break" spacing refers to a distance at which, when an external force is applied, it is difficult for the uncut portion between adjacent cutting lines to break, making it difficult for the adjacent cutting lines to join together.

[0025] 1 to 4, the pair of outer flaps 14 are connected to the upper ends (tips) of the pair of side plates 13 via bent portions 18. The outer flaps 14 are folded toward the center in the width direction relative to the side plates 13 and overlap the inner flaps 12. The total length of each of the pair of outer flaps 14, from the base ends 14a connected to the side plates 13 to the tips 14b, is set to a dimension that allows them to overlap with each other in the packaged state of maximum thickness shown in FIGS.

[0026] 5, the pair of outer flaps 14 are connected to the left and right outer sides of the side plate 13 via fold lines 18a that form the fold portion 18. The fold lines 18a are formed by lead creases similar to the fold lines 17a.

[0027] Next, the configuration for packaging the article G in a stepless manner will be specifically described.

[0028] 1, 3, and 5, both widthwise side edges 12c of the inner flap 12 are inclined toward the center in the widthwise direction from the base end 12a to the tip end 12b. This inclination allows the side panels 13 to incline (fall) toward the center in the widthwise direction when packaging an article G. More specifically, the width W1 of the base end 12a of the inner flap 12 is slightly smaller than the width of the bottom panel 11. Meanwhile, the width W2 of the tip end 12b of the inner flap 12 is narrower than the width W1 of the base end 12a.

[0029] If the inclination angle of the side edge 12c of the inner flap 12 is too large, it will be impossible to ensure a sufficient area to cover the article G. On the other hand, if the inclination angle of the side edge 12c is too small, it may hinder the side panel 13 from collapsing when packaging the article G. Therefore, the width W2 of the tip 12b is preferably set in the range of 50% to 95% of the width W1 of the base end 12a, and in this embodiment it is set to 84%. Here, the width W2 of the tip 12b is defined as the distance from one end to the other end of the tip 12b of the inner flap 12 when both sides of the tip 12b are not chamfered.

[0030] 2 and 5, fold lines (second fold lines) 20, which are formed by lead creases similar to the fold lines 17a, are provided on both widthwise sides of the inner flap 12 so as to extend along the lengthwise direction. By forming these fold lines 20, flexible portions 12d are formed on the outer sides of the inner flap 12 in the widthwise direction.

[0031] The fold line 20 includes a first portion 20a and a second portion 20b. The first portion 20a extends in the longitudinal direction. More specifically, the first portion 20a extends parallel to the side edge 12c from the tip 12b of the inner flap 12 toward the base end 12a. The end of the first portion 20a on the base end 12a side is positioned with a gap between it and the fold line 16a. The second portion 20b extends at an angle outward in the width direction relative to the first portion 20a. More specifically, the second portion 20b extends from the end of the first portion 20a on the base end 12a side to the corner of the inner flap 12 on the base end 12a side.

[0032] The flexible portion 12d can bend relative to the main body portion of the inner flap 12 between the pair of fold lines 20 when the side plate 13 abuts against it. If the width of the flexible portion 12d in the width direction, i.e., the distance between the first portion 20a of the fold line 20 and the side edge 12c, is made excessively small, the flexible portion 12d may hinder the side plate 13 from collapsing and may make it difficult for the flexible portion 12d to bend along the article G. If the width of the flexible portion 12d is made excessively large, the force is distributed throughout the flexible portion 12d, making it difficult to bend along the fold line 20, which may result in the side plate 13 being hindered from collapsing. For this reason, the width of the flexible portion 12d is preferably set in the range of 3 mm to 50 mm, and is set to 30 mm in this embodiment.

[0033] 5 and 7, the regions of the tip ends 12b of the pair of inner flaps 12 overlap each other in the packaged state. The overlapping portion 12e and the flexible portion 12d in the packaged state with the minimum thickness shown in FIGS. 1 and 2 are each stepped. This reduces the thickness of the overlapping overlapping portion 12e in both the packaged state with the minimum thickness shown in FIGS. 1 and 2 and the packaged state with the maximum thickness shown in FIGS. 3 and 4. This also reduces the stiffness (flexibility) of the cardboard sheet 1, imparting flexibility to the overlapping portion 12e and the flexible portion 12d.

[0034] 5 and 7, in the packaging material 10 of this embodiment, the core 4 constituting the cardboard sheet 1 extends in the length direction. The flexibility of the core 4 in the length direction is lower than the flexibility in the width direction, which is perpendicular to the core 4. Therefore, in this embodiment, to improve flexibility in the length direction, multiple weakened lines 21 extending in the width direction are provided in the inner flap 12 in an area other than the overlapping portion 12e. The multiple weakened lines 21 are general-purpose lines and are provided at intervals in the length direction and width direction. This reduces the stiffness (flexibility) of the cardboard sheet 1 and provides flexibility to the inner flap 12, allowing it to be placed along the article G. However, the packaging material 10 may be formed so that the core 4 of the cardboard sheet 1 extends in the width direction, or the entire inner flap 12 may be corrugated.

[0035] On both sides of the side plate 13 in the longitudinal direction, fold lines (third fold lines) 22 are provided for deforming a portion of the side plate 13 to flex the flexible portion 12d of the inner flap 12 and bring it closer to the article G. The fold line 22 is formed by a lead crease similar to the fold line 17a, and is inclined toward the center in the longitudinal direction as it moves away from the bottom plate 11 toward the outer flap 14. The lower end of the fold line 22 is positioned at a distance from the fold line 17a, and the upper end of the fold line 22 is positioned at a distance from the fold line 18a.

[0036] 1, 3, and 5, one of the pair of outer flaps 14 is provided with an insertion piece 24 and the other with an insertion hole 25 in order to maintain the packaged state. The lengthwise dimensions of the insertion piece 24 and the insertion hole 25 are smaller than the shorter dimension of the delivery slip (not shown). This allows the insertion piece 24 and the insertion hole 25 to be covered by the delivery slip whether the delivery slip is attached so that its longitudinal direction is along the lengthwise direction or the widthwise direction of the packaging material 10.

[0037] The insertion piece 24 has a protruding portion 24a protruding from the tip 14b of the outer flap 14. The insertion piece 24 is separated from the main body of the outer flap 14 by a pair of slits 24b formed by cutting lines extending from the tip 14b to the base end 14a. The base end of the protruding portion 24a of the insertion piece 24 and the tip of the slit 24b are aligned and extend linearly. A fold line 24c is defined between the base ends of the pair of slits 24b by a general-purpose crease.

[0038] The insertion hole 25 is generally trapezoidal, spaced from the tip 14b of the outer flap 14, and punched to extend in the longitudinal direction. An insertion piece 24 can be inserted into the insertion hole 25 in both the minimum thickness packaging state shown in Figures 1 and 2 and the maximum thickness packaging state shown in Figures 3 and 4. An edge 25a of the insertion hole 25 away from the tip 14b is located at a position that coincides with the tip 14b of the outer flap 14, which has the insertion piece 24, in the longitudinal direction in the maximum thickness packaging state shown in Figures 3 and 4.

[0039] The total length L of the slit 24b, the angle θ between the bottom plate 11 and the side plate 13, and the height direction length H of the bottom plate 11 and the side plate 13 are formed to satisfy the following formula (1): However, formula (1) may be adjusted taking into account the thickness and deflection of the cardboard sheet 1.

[0040] [Number 1] L≧cosθ×H×2 (1) L: Total length of the slit θ: Angle between the bottom plate and the side plate H: Height of the side panel

[0041] With the insertion piece 24 and insertion hole 25 configured in this manner, in the packaging state of the minimum thickness shown in Figures 1 and 2, the insertion piece 24 can be inserted into the insertion hole 25 up to the base of the slit 24b. On the other hand, in the packaging state of the maximum thickness shown in Figures 3 and 4, the insertion piece 24 can be securely inserted into the insertion hole 25 by the amount of protrusion of the protruding portion 24a. Furthermore, it is possible to determine whether the maximum thickness set by the specifications is exceeded based on the positional relationship between the tip 14b of the outer flap 14 having the insertion piece 24 and the edge 25a of the insertion hole 25.

[0042] 1, 3, and 5, the outer flap 14, which includes the insertion hole 25, is provided with a tear line 27 for opening. The tear line 27 is generally V-shaped and is composed of one operating portion 27a and two one-sided zippers 27b. The operating portion 27a is provided in the center of the bent portion 18 between the outer flap 14 and the side panel 13, and is separated from other portions by a generally U-shaped tear line. The one-sided zippers 27b are formed so as to expand outward from both ends of the operating portion 27a toward the tip 14b of the outer flap 14, and extend to the side edges of the outer flap 14. The one-sided zipper 27b is composed of a plurality of first tear lines 27c provided at intervals and a plurality of second tear lines 27d provided at the ends of the plurality of first tear lines 27c on the operating portion 27a side.

[0043] Next, the operation of packaging the article G with the packaging material 10 will be described.

[0044] First, in the unfolded state shown in FIG. 5, an article G is placed on the bottom plate 11. Next, as shown in FIG. 7, the pair of inner flaps 12 are folded upward and toward the center in the longitudinal direction relative to the bottom plate 11. In this case, the inner flaps 12 are folded only at the folding portion 16 defined by a single folding line 16a, so that the worker will not mistakenly fold other portions. Furthermore, since multiple weakened lines 21 are provided on the base end 12a side of the inner flaps 12, the inner flaps 12 can be reliably folded to fit the shape of the article G regardless of the thickness and shape of the article G. Furthermore, since the tip end 12b side of the inner flaps 12 has a stepped overlapping portion 12e, the thickness of the packaging material 10 in the packaged state can be reduced.

[0045] Next, the pair of side panels 13 are folded upward relative to the bottom panel 11, and the outer flaps 14 are each folded toward the center in the width direction relative to the pair of side panels 13. At this time, the side panels 13 are only folded at fold portion 17 defined by a single fold line 17a, and the outer flaps 14 are only folded at fold portion 18 defined by a single fold line 18a, so that the worker will not mistakenly fold other portions. The inclination angle (angle θ) of the side panels 13 relative to the bottom panel 11 varies depending on the thickness of the article G; the thinner the article G, the more acute the angle; the thicker the article G, the closer it is to 90 degrees, and at its thickest, it is 90 degrees (upright).

[0046] Next, the insertion piece 24 of one of the pair of outer flaps 14 is inserted into the insertion hole 25 of the other. Thereafter, as shown in FIG. 8, the side plate 13 outside the fold line 22 is pressed toward the bottom plate 11. In other words, the four corners of the packaging material 10 are pinched so as to be compressed. As a result, the side plate 13 is mountain-folded along the fold line 22, and the base end 14a of the outer flap 14 is valley-folded along the fold portion 18, and the flexible piece 12d located inside these is bent downward (toward the bottom plate 11). As a result, the adhesion of the inner flap 12 to the article G can be improved. Note that the reference numeral 30 in FIG. 8 denotes a fold line formed by the outer flap 14 being bent by the bending of the side plate 13.

[0047] Next, the pair of outer flaps 14 are pulled toward each other. This pulls the upper ends of the pair of side panels 13 toward the center in the width direction, tilting them inward according to the thickness of the article G and pressing against the side edge 12c of the inner flap 12. As a result, the flexible piece 12d of the inner flap 12 is further bent downward. Finally, with the outer flaps 14 pulled toward the center in the width direction, the delivery slip is attached to the pair of slits 24b across the pair of outer flaps 14. This maintains the packaging material 10 in its packaged state.

[0048] As described above, the packaging material 10 of this embodiment can easily and reliably package the article G in accordance with the thickness of the article G without requiring any complicated adjustment work.

[0049] The packaging material 10 configured in this manner has the following features.

[0050] A pair of inner flaps 12 connected to the bottom plate 11 are each folded back along a single fold line 16a so as to fit the article G on the bottom plate 11, and the gap S between the bottom plate 11 and the inner flaps 12 is each covered by the side plates 13 folded back against the bottom plate 11. In other words, there is no need to change the folding position of the inner flaps 12 depending on the thickness of the article G to be packaged. Furthermore, stepless adjustment is possible simply by folding back the inner flaps 12 against the bottom plate 11 so as to fit the article G. This configuration makes it impossible to make a folding mistake, thereby improving the workability when packaging the article G.

[0051] A flexible portion 12d is formed on the outer side of the fold line 20 provided on the inner flap 12, and can bend when contacted with the side plate 13. Therefore, the flexible portion 12d can be arranged in close contact with the inner flap 12 according to the article G to be accommodated, so that movement of the article G inside can be suppressed and the article G can be packaged in a stable state.

[0052] Both side edges 12c of the inner flap 12 are inclined toward the center from the base end 12a connected to the bottom plate 11 toward the tip end 12b. This prevents the side plates 13, which move in conjunction with the pair of outer flaps 14, from getting caught on the side edges 12c of the inner flap 12 and interfering with the work when the pair of outer flaps 14 are narrowed toward the center in the width direction.

[0053] The flexible portion 12d is corrugated to compress the thickness of the cardboard sheet 1. This allows the flexible portion 12d to be reliably positioned in close contact with the article G to be accommodated in the inner flap 12, allowing the article G to be packaged in a stable state.

[0054] On both sides of the side plate 13, there are provided fold lines 22 that incline toward the center as they move away from the bottom plate 11. This allows the inner flaps 12 to be deformed to fit the article G by compressing the portions of the side plate 13 outside the fold lines 22, thereby improving workability when packaging the article G.

[0055] One outer flap 14 is provided with an insertion piece 24 defined by a pair of slits 24b, and the other outer flap 14 is provided with an insertion hole 25, with the total length L of the slit 24b, the angle θ formed between the bottom plate 11 and the side plate 13, and the length H of the side plate 13 in the height direction satisfying L ≥ cos θ × H × 2. This allows the insertion piece 24 to be inserted into the insertion hole 25 even for articles G of different thicknesses, so the articles G can be maintained in a packaged state (temporarily fastened).

[0056] The inner flap 12 is provided with a plurality of weakened lines 21 for imparting flexibility to the inner flap 12. This allows the inner flap 12 to be deformed according to the shape of the article G, enabling it to be packaged in a securely tightly closed state.

[0057] The present invention is not limited to the configuration of the above embodiment, and various modifications are possible.

[0058] For example, the flexible portion 12d may not be stepped. The overlapping portion 12e may not be stepped. The inner flap 12 may not be provided with the weakened line 21. The side plate 13 may not be provided with the fold line 22.

[0059] The insertion piece 24 and the insertion hole 25 can be changed as needed as long as they are configured to temporarily secure the article G in a packaged state. In particular, the method for determining the overall length L of the slit 24b can be changed depending on the thickness determined by the specifications. Furthermore, the packaging material 10 may not be configured to include the insertion piece 24 and the insertion hole 25. [Explanation of symbols]

[0060] 1 cardboard sheet 2. Front liner 3 Back liner 4 Core 10 Packaging materials 11 Bottom plate 12 Inner flap 12a proximal end 12b tip 12c side edge 12d flexible part 12e Superimposed part 13 Side panel 14 Outer flap 14a proximal end 14b tip 16 Bend section 16a Folding line (first folding line) 17 Bend section 17a folding line 18 Bend section 18a folding line 20 Folding curve (second folding curve) 20a Part 1 20b 2nd part 21 Weakened Lines 22 Folding line (3rd folding line) 24 Locking piece 24a Protrusion 24b slit 24c folding line 25 Locking hole 25a Edge 27 Break Line 27a Control unit 27b one-sided zipper 27c 1st cutting line 27d 2nd cutting line 30 Line G Goods S void L Total length of slit θ Angle between the bottom plate and the side plate H Distance between the bottom plate and the other outer flap X length direction (first direction) Y Width direction (second direction) Z thickness direction

Claims

1. The bottom plate and a pair of inner flaps connected to both ends of the bottom plate in the first direction and folded back along a single first fold line so as to fit the article on the bottom plate; a pair of side plates connected to both ends of the bottom plate in a second direction intersecting the first direction and bent so as to cover a gap between the bottom plate and the inner flap; a pair of outer flaps respectively connected to the tips of the pair of side plates and folded so as to overlap the inner flaps; Equipped with A packaging material in which a second fold line is formed on both sides of the inner flap in the second direction, extending along the first direction, and a flexible portion is formed outside the second fold line that can bend when the side panel abuts against the second fold line.

2. The packaging material according to claim 1 , wherein both side edges of the inner flap in the second direction are inclined from a base end connected to the bottom plate toward a tip end toward a center in the second direction.

3. It is made of a cardboard sheet with a corrugated core placed between a pair of liners. The packaging material according to claim 1 or 2, wherein the flexible portion is corrugated so as to compress the thickness of the cardboard sheet.

4. The packaging material according to claim 1 or 2, wherein a third fold line is provided on each of both sides of the side plate in the first direction, the third fold line being inclined toward the center in the first direction as it extends away from the bottom plate.

5. The pair of outer flaps are formed with dimensions such that their tips overlap each other, One of the pair of outer flaps is provided with an insertion piece that protrudes from a tip end of the one outer flap and is defined by a pair of slits that extend from the tip end of the one outer flap toward a base end thereof, The other outer flap of the pair of outer flaps is provided with an insertion hole into which the insertion piece is inserted, The packaging material according to claim 1 or 2, wherein the overall length of the slit, the angle between the bottom plate and the side plate, and the length of the side plate satisfy the following: L ≥ cos θ × H × 2 L: Total length of the slit θ: Angle between the bottom plate and the side plate H: Height of the side panel

6. 3. The packaging material according to claim 1, wherein the inner flap has a plurality of weakened lines extending in the second direction at intervals in the first direction and the second direction to impart flexibility to the inner flap.

7. The bottom plate and a pair of inner flaps connected to both ends of the bottom plate in the first direction and folded back along a single first fold line so as to fit the article on the bottom plate; a pair of side plates connected to both ends of the bottom plate in a second direction intersecting the first direction and bent so as to cover a gap between the bottom plate and the inner flap; a pair of outer flaps respectively connected to the tips of the pair of side plates and folded so as to overlap the inner flaps; Equipped with The packaging material, wherein both side edges of the inner flap in the second direction are inclined from a base end connected to the bottom plate toward a tip end toward a center in the second direction.

Images