JP3212765B2 - Packing cushioning structure and packing cushioning material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushioning structure for packing and a cushioning material for packing used for cushioning an object to be packed such as electric equipment.

[0002]

2. Description of the Related Art The role of packaging material ends as soon as a product reaches a user. For the user, the packaging material is
The image of "bulky garbage" is persistent. In addition, in recent years, from the viewpoint of environmental issues, legal tightening of packaging materials has become severe.

[0003] One of the basic policies for reducing refuse from packaging materials is to use recyclable materials.

As shown in FIG. 13, a conventional packing structure of this type is provided at each corner of a packing box 80 and a packing object 81, and is provided together with the packing object 81 together with the packing box 80. The packing cushioning member 82 inserted into the container and in contact with the object to be packed 81 and the inner wall portion of the packing box 80, and a holding lid 83 inserted into the packing box 80 and holding the object to be packed 81. Some have been provided.

In such a packing structure, a packing cushion made of styrofoam is used for the packing cushion 82, and a styrofoam spacer is attached to a base 84 made of corrugated cardboard for the holding cover 83. 85 was used.

[0006]

As described above, in the conventional packing structure, the packing cushioning material 8 made of polystyrene foam is used.
2 is used, and the holding lid 83 has a spacer 85 made of styrene foam.

[0007] Since this styrofoam is a resin, the furnace will be damaged when incinerated, and it will be bulky and difficult to bury. In addition, it is conceivable to pulverize and use it for building materials or return it to polystyrene (PS) resin before using it for injection molded products such as cassette tapes and toys. However, at present, this recycling is costly. And have
Immediately, there has been a demand for a packaging structure that does not damage the furnace even when incinerated, is not bulky, and can be easily recycled, especially the appearance of a cushioning material for packaging.

The present invention has been made in view of the above circumstances, and a first object of the present invention is to prevent a large number of piles from being bulky, requiring a large storage space, and An object of the present invention is to provide a packing cushioning structure that facilitates transportation.

A second object of the present invention is not only to enable incineration after use, but also to facilitate recycling, to be environmentally friendly, and to obtain an inexpensive cushioning property. An object of the present invention is to provide a cushioning material for packing.

[0010]

SUMMARY OF THE INVENTION In order to achieve the first object, the present invention is provided at each corner of a packaged object, and is inserted into a packing box together with the packaged object. And a second cushion connected to the first surface portion (22) and the left front edge of the first surface portion (22) via the first folding line portion (19a). A surface portion (23) and a third surface portion (24) connected to the left rear edge of the first surface portion (22) via a second folding line portion (19b).
And a third folding line portion (19c) at the right rear edge of the first surface portion (22).
A fourth surface portion (25) connected to the third surface portion (24) via a fourth fold line portion (19d); and a fourth surface portion (26) connected to the left front edge portion of the third surface portion (24) via the fourth fold line portion (19d). Fifth fold line at left rear edge of surface (25)
(19e) and a sixth surface portion (27) that is continuous with the first engagement concave portion (27) at the left front edge of the second surface portion (23). 31), a first engagement projection (30) on the left front edge of the fifth surface (26), and the sixth surface (27).
A second engaging projection (33) on the left front edge of the sixth surface
The second front surface portion (23) is removed from the first front surface (23) by the first engagement portion (34).
Fold line portion (19a) to overlap the first surface portion (22), and the fifth surface portion (26) is folded at the fourth fold line portion (19d) to form the third surface portion (24). ), The sixth surface portion
(27) is folded at the fifth fold line portion (19e) to form the fourth
The fifth and third surface portions (26, 24) are further folded at the second fold line portion (19b),
The overlapped sixth and fourth surface portions (27, 25) are folded at the third fold line portion (19c) to form the first engagement recesses (3
1) that the second engagement projection (33) is engaged with the second engagement recess (34), and the first engagement projection (30) is engaged with the second engagement projection (33). Features.

According to another aspect of the present invention, there is provided a cushioning material structure for packing according to the first aspect, wherein the first engagement recess (31) and the second engagement recess are provided. The planar shape of (34) is trapezoidal, and the first engagement protrusion (30) and the second
The planar shape of the engaging projection (33) is inverted trapezoid.

Further, in order to achieve the first object, the present invention provides a method for providing a packaged object which is provided at each corner of the packaged product and inserted into the packing box together with the packaged product. A cushioning material for holding the first surface portion (22) and the first surface portion
(22), a second surface portion (23) connected to the left front edge portion via a first fold line portion (19a), and a second fold line portion (22) on the left rear edge portion of the first surface portion (22). 19b) and a third surface portion (24)
A fourth surface (25) connected to the right rear edge of the surface (22) via a third fold line (19c), and a fourth fold line to the left front edge of the third surface (24). Fifth surface portion (26) connected via portion (19d)
And a fifth folding line portion (19e) on the left rear edge of the fourth surface portion (25).
And a sixth surface portion (27) that is continuous with the engaging projection (27) formed on the left front edge of the fifth surface portion (26). 30) with the sixth surface (2
7), the second surface portion (23) is folded at the first fold line portion (19a) from the developed state in which the engagement recesses (34) each having a trapezoidal planar shape are formed on the right front edge portion. The first surface portion
(22), and the fifth surface portion (26) is connected to the fourth fold line portion.
(19d), the third surface portion (24), the sixth surface portion (27) is folded at the fifth fold line portion (19e), and the fourth surface portion (25). Further, the superposed fifth and third surface portions (26, 24) are connected to the second folding line portion (19b).
The sixth and fourth surface portions (27, 2)
5) is folded at the third fold line portion (19c) to form the engagement recess.
(34) The engaging projection (30) is engaged with the engaging projection (30) to assemble.

Further, in order to achieve the second object, the present invention provides a method for providing a packaged object which is provided at each corner of a packaged product and inserted into a packing box together with the packaged product. A cushioning material for packing, comprising: a first surface portion (22);
A second surface portion (23) connected to the left front edge of the surface portion (22) via a first fold line portion (19a), and a second fold line at the left rear edge of the first surface portion (22). A third surface portion (24) connected via a portion (19b)
And a third folding line portion (19c) at the right rear edge of the first surface portion (22).
A fourth surface portion (25) connected to the third surface portion (24) via a fourth fold line portion (19d); and a fourth surface portion (26) connected to the left front edge portion of the third surface portion (24) via the fourth fold line portion (19d). Fifth fold line at left rear edge of surface (25)
(19e) and a sixth surface portion (27) that is continuous with the first engagement concave portion (27) at the left front edge of the second surface portion (23). 31), a first engagement projection (30) on the left front edge of the fifth surface (26), and the sixth surface (27).
A second engaging projection (33) on the left front edge of the sixth surface
A second engagement recess (34) is formed in the right front edge of (27).

According to a second aspect of the present invention, there is provided a cushioning material for packaging according to the fourth aspect of the present invention.
The first engagement recess (31) and the second engagement recess (34) have trapezoidal planar shapes, and the first engagement protrusions (30) and the second engagement protrusions (33) have planar shapes. Has an inverted trapezoidal shape.

Further, in order to achieve the second object, the present invention provides a method for providing a packaged object which is provided at each corner of a packaged product and inserted into a packing box together with the packaged product. A cushioning material for packing, comprising: a first surface portion (22);
A second surface portion (23) connected to the left front edge of the surface portion (22) via a first fold line portion (19a), and a second fold line at the left rear edge of the first surface portion (22). A third surface portion (24) connected via a portion (19b)
And a third folding line portion (19c) at the right rear edge of the first surface portion (22).
A fourth surface portion (25) connected to the third surface portion (24) via a fourth fold line portion (19d); and a fourth surface portion (26) connected to the left front edge portion of the third surface portion (24) via the fourth fold line portion (19d). Fifth fold line at left rear edge of surface (25)
(19e) and a sixth surface portion (27) continuous with the fifth surface portion (26), and a left front edge of the fifth surface portion (26) has an inverted trapezoidal planar shape. A mating projection (30) is provided on the right front edge of the sixth surface (27).
Are formed respectively.

[0016]

According to this structure, the packing cushioning material structure and the packing cushioning material have a developed shape in which a left side portion and a right side portion are connected to each other at least on a bottom portion through a folding line from a single material. Since the packing cushioning material is assembled by folding the left side surface portion and the right side surface portion at the folding line portion with respect to the bottom portion from the expanded state thereof, even if a large number of these packing cushioning materials are piled up, it is bulky. This eliminates the need for a large storage space, facilitates transportation, and makes the assembly of the cushioning material for packing more robust (in a state where the cushioning material for packing after assembly is difficult to unravel). The handling of the cushioning material for packing after assembly is facilitated, and the workability of packing the items to be packed is improved.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a packing structure using a packing cushioning material according to the present invention. This packing structure includes a packing box 1, a plurality of packing cushioning materials 2, and a holding lid 3.

The packing box 1 is a generally used cardboard box, and includes left and right sides 4 and 5 and front and rear sides 6 and 7.
And left and right side surfaces 4 and 5 and front and rear side surfaces 6 and 7 with foldable lid pieces 4 on upper edges thereof.
a, 5a, 6a, and 7a, and these lid pieces 4a, 5a
The opening 1a is opened and closed by a, 6a and 7a.

The cushioning material for packing 2 is a so-called corner pad, which is applied to each corner of the package 9. The cushioning material 2 for packing is made of corrugated paper 10. This corrugated paper 10 is shown in FIG.
As shown in (1) and (2), a corrugated sheet core material 13 is interposed between the double flute 11 and the inner kraft runner 12 and adhered to each other, and between the inner kraft runner 12 and the outer kraft runner 14. A double flute 11, a corrugated sheet core 13, and an inner kraft runner 12 form an A flute 100, and the inner kraft runner 12 is The plate core 15 and the outer craft runner 14 constitute a B flute 200. In this case, the height of the corrugated sheet core 13 of the A flute 100 is equal to the height of the corrugated sheet core 15 of the B flute 200.
A flute 100 is softer than B flute 200.
The cushioning material 2 for packing is formed by cutting and corrugating the corrugated paperboard 10 with a cutting machine, and then folding and assembling the corrugated paperboard 10.

Next, the packing cushioning material 2 shown in FIG. 1 will be described in detail with reference to FIGS. 3, 4 and 5. FIG.

The cushioning material 2 for packing is cut by the cutting machine into a development mold having a shape shown in FIG. Then, in the unfolded type shown in FIG. 3, Y is the front, Z is the rear, L is the left,
When R indicates the right, the packing cushioning material 2 includes a first surface portion 22 and a second surface portion 23 connected to the left front edge of the first surface portion 22 via the first fold line portion 19a. A third rear surface portion 24 connected to the left rear edge of the first surface portion 22 via the second fold line portion 19b, and a third rear fold line portion 19c to the right rear edge portion of the first surface portion 22 via the third fold line portion 19c. A fourth surface portion 25 connected to the third
The fifth surface 26 connected to the left front edge of the surface 24 via the fourth fold 19d, and the sixth surface 26 connected to the left rear edge of the fourth surface 25 via the fifth fold 19e. Surface portion 27. The first to fifth folding line portions 19a
To e, the double flute 1 outside the corrugated paper 10
1 is formed by so-called half blanking so as to remain without being cut.

An engagement recess 31 is formed at the left front edge of the second surface portion 23, and an engagement protrusion 30a is formed at the left rear edge, and the left front edge of the fifth surface portion 26 is formed. , An engagement projection 30 is formed on the right front edge, and an engagement recess 31a is formed on the right front edge. An engagement recess 34 is formed on the right front edge of the sixth surface 27, and an engagement protrusion 33 is formed on the left front edge of the sixth surface 27.

Then, as shown in FIG.
Is folded at the first folding line portion 19a and overlaps the first surface portion 22, the fifth surface portion 26 is folded at the fourth folding line portion 19d and overlaps the third surface portion 24, and the sixth surface portion 27 is folded 5 and folded on the fourth surface 25. Next, the superimposed fifth and third surface portions 26 and 24 are
The sixth and fourth surface portions 27 and 25 that are folded and overlapped at the folding line portion 19b are folded at the third folding line portion 19c so that the engagement recesses 31 are engaged with the engagement protrusions 33 and The engagement protrusion 30 is engaged with the recess 34 and the engagement protrusion 30a is engaged with the engagement recess 31a. As shown in FIG. Get.

The bottom part D of the finished product 36 shown in FIG.
In the left side surface portion E and the right side surface portion F, the B flute 200 of the corrugated paper 10 is located on the surface portion, and A
The flute 100 is located. Since the B flute 200 is harder than the A flute 100 and the A flute 100 has excellent cushioning (cushioning properties), the B flute 20
When 0 touches the inner surface of the article 9 to be packed and the inner surface of the packing box 1, the load is received on the entire surface, and the load propagates to the entire inside of the A flute 100 to obtain a good cushioning property.

In the cushioning material 2 for packing shown in FIG. 3, the plan shapes of the engaging recesses 31, 31a and 34 are shown in FIG.
As shown in FIG.
The planar shape of the engaging projections 33, 30a, 30 with which the a, 34 engages may be inverted trapezoidal. In this case, the engagement recesses 31,
31a and 34, the dimension L1 of the short side portion 80 and the engagement protrusion 33,
The dimension L2 of the short side portion 81 of 30a, 30 is the same. Then, the engaging protrusions 3 are inserted into the engaging recesses 31, 31a, 34.
When the three sides 30, 30a, 30 intersect at right angles, the short sides 80, 81 coincide with each other, and the engaging projections 33, 30a, 3
The zero acute angle portion 82 is hooked on the lower edges of the left and right sides 83, 84 of the engagement concave portions 31, 31a, 34, thereby ensuring the engagement.

As shown in FIG. 7, the engaging recesses 31, 31a, 34 have a quadrangular planar shape with triangular projections 87, 88 formed on the left and right sides 85, 86, respectively. The planar shape of the engaging projections 33, 30a, 30 with which the engaging concave portions 31, 31a, 34 are engaged is a quadrangular shape in which triangular convex portions 91, 92 are formed on the left and right sides 89, 90, respectively. You may do it. Then, the engagement recesses 31 and 3
When the engaging protrusions 33, 30a, 30 are engaged with the engaging protrusions 33, 30a, 30 at right angles to the engaging protrusions 1a, 34, the protrusions 87, 88 of the engaging recesses 31, 31a, 34 correspond to the left of the engaging protrusions 33, 30a, 30, The right side portions 89, 90 bite into the A flute 100, and the projections 91, 92 of the engagement projections 33, 30a, 30 are engaged with the engagement recesses 31,
A flute 10 on left and right sides 85 and 86 of 31a and 34
It cuts into zero to ensure its engagement.

The planar shape of the engaging recesses 31, 31a, 34 is square as shown in FIG.
Corrugated portions 93 are formed on the right side portions 85 and 86, and the engagement protrusions 33 and 30 with which the engagement concave portions 31, 31a and 34 engage.
The planar shape of a, 30 may be square, and the wavy portion 94 may be formed on the left and right sides 89, 90 thereof. Then, the engaging projections 33, 30a, 3 are inserted into the engaging recesses 31, 31a, 34.
0 engages at right angles to each other,
a, 34 of the engagement projections 33, 30a, 30
Of the right and left sides 89, 90 of the wavy portion 94 to secure the engagement.

The engaging recesses 31, 31a, 34 are formed in a square shape as shown in FIG.
Serrated portions 95 are formed on the right side portions 85, 86, and the engaging projections 33, 3 with which the engaging concave portions 31, 31a, 34 engage.
The plane shape of Oa and 30 may be square, and the serrated portions 96 may be formed on the left and right sides 89 and 90 thereof. Then, the engagement protrusions 33, 30 are inserted into the engagement recesses 31, 31a, 34.
a, 30 are engaged at right angles to each other.
1, 31a, 34 are provided with the engagement projections 33, 3
It cuts into the serrations 96 of the left and right sides 89, 90 of Oa, 30 to ensure its engagement.

Next, the pressing cover shown in FIG. 1 will be described in detail. As shown in FIGS. 10 and 11, the holding lid 3 has a lid body 37 made of corrugated cardboard 10 conforming to the shape of the opening 1 a of the packing box 1.
A plurality of bent pieces 38 are formed by cuts 39 in the surface portion of. These bent pieces 38 are cantilevered pieces,
An engagement protrusion 40 is provided at a tip portion thereof, and folding lines 41 and 42 are formed at a base portion and an intermediate portion. An engaging hole 43 is formed on the surface of the lid body 37 at the base of the bent piece 38, and a notch 44 is formed on one end of the lid body 37.

The outer shape of the lid body 37, the bent pieces 38, the fold lines 41 and 42 of the bent pieces 38, the engaging holes 43 and the cutouts 44 are formed at once by a cutting machine. The lines 41 and 42 are formed by crushing the corrugated paper 10 into a line.

The bent piece 38 is bent upward at a fold line 41 and bent downward at a fold line 42 to form the bent piece 38 into a mountain shape. Each of the bent pieces 38 engages with each other to form a spacer S which also serves as a buffer.

Next, the packing of the article 9 to be packed using the packing box 1, the plurality of packing cushioning materials 2 and the presser cover 3 configured as described above will be described.

First, as shown in FIG. 1, the packing cushioning material 2 is applied to each corner of the article to be packed 9 and inserted into the packing box 1. The body 3 is inserted into the packing box 1, and the cords 45 connected to the article to be packed 9 are led out of the notch 44 of the holding lid 3 onto the holding lid 3, and the cords 45. Is located between the spacers S. Then, the lid pieces 4a, 5a of the packing box 1,
The opening 1a is closed by 6a and 7a. In this case, the lid piece 4
The inner surfaces of a, 5a, 6a, and 7a are in contact with the upper end of the spacer S.

The corrugated paper 10 having one A flute 100 and one B flute 200 was used as the material of the cushioning material 2 for packing and the cover 3, but as shown in FIG. 10, 10 to A flute 10
A material having a double structure bonded at the zero portion may be used, or a material other than the corrugated paper 10, for example, a nonwoven fabric or a pulp mold may be used.

[0035]

As described above, the packing cushioning material structure and the packing cushioning material of the present invention connect a left side portion and a right side portion at least to the bottom portion through a folding line from a single material. The packing cushioning material is assembled in such a way that the packing cushioning material is assembled by folding the left side face and the right side face at the folding line portion with respect to the bottom face from the state of the unfolded shape. It does not become bulky even when piled up, does not require a large storage space, is easy to transport, and has a strong assembling of the cushioning material for packing. ), Handling of the cushioning material for packing after assembly is facilitated, and packing workability of the article to be packed is improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a packing structure provided with a cushioning material structure for packing according to the present invention.

FIG. 2A is a perspective view of a corrugated cardboard. (2) is a sectional view of the corrugated paper.

FIG. 3 is a perspective view showing an expanded state of the cushioning material for packing.

FIG. 4 is a perspective view of the packing cushioning material in a folded state.

FIG. 5 is a perspective view of the completed cushioning material for packing as viewed from the inner surface side.

FIG. 6 is a plan view showing a modification of the shapes of the engagement recess and the engagement protrusion.

FIG. 7 is a plan view showing another modified example of the shapes of the engagement concave portion and the engagement protrusion.

FIG. 8 is a plan view showing another modification of the shapes of the engagement recess and the engagement protrusion.

FIG. 9 is a plan view showing another modification of the shapes of the engagement recess and the engagement protrusion.

FIG. 10 is a plan view of a holding cover body.

FIG. 11 is a perspective view of a holding cover.

FIG. 12 is an explanatory diagram of the bonding of two pieces of corrugated paper.

FIG. 13 is an exploded perspective view of a conventional packing structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Packing box 2 Packing cushioning material 3 Holding lid 9 Packing thing 10 Corrugated cardboard 19 Folding line part 38 Folding piece 40 Engagement protrusion part 41, 42 Folding line 43 Engagement hole part D bottom part E Left side part F Right side

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-219471 (JP, A) JP-A 6-78279 (JP, U) JP-A 6-444757 (JP, U) JP-A 51- 138470 (JP, U) Patent 349073 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B65D 81/113

Claims (6)

(57) [Claims] 1. A packing cushion, which is provided at each corner of a packaged object and is inserted into a packaging box together with the packaged product and holds the packaged product, comprises a first surface portion, A second surface portion connected to the left front edge portion of the first surface portion via the first folding line portion, a third surface portion connected to the left rear edge portion of the first surface portion via the second folding line portion, A fourth surface connected to the right rear edge of the first surface via a third folding line, and a fifth surface connected to the left front edge of the third surface via a fourth folding line. And a sixth surface portion connected to a left rear edge portion of the fourth surface portion via a fifth fold line portion, and is formed of a single material, and a left front edge portion of the second surface portion is formed on the left front edge portion of the second surface portion. Represents a first engagement recess, a first engagement protrusion at a left front edge of the fifth surface portion, a second engagement protrusion at a left front edge of the sixth surface portion, In the right front edge of the surface From the expanded state in which the concave portions are formed, the second surface portion is folded at the first fold line portion and overlapped with the first surface portion, and the fifth surface portion is folded at the fourth fold line portion. , The sixth surface portion is folded at the fifth fold line portion and overlapped on the fourth surface portion, and the superimposed fifth and third surface portions are further overlapped with the second surface portion. The sixth and fourth folded and overlapped at the folding line portion
Are folded at the third fold line portion, and the second engagement protrusion is provided in the first engagement recess, and the first engagement protrusion is provided in the second engagement recess, respectively. A packing cushioning structure having a structure of engaging and assembling. 2. The method according to claim 1, wherein the first engagement recess and the second engagement recess have a trapezoidal planar shape, and the first engagement protrusion and the second engagement projection have an inverted trapezoidal planar shape. The packing cushioning structure according to claim 1, wherein: 3. A packing cushion, which is provided at each corner of the packaged object and is inserted into the packaging box together with the packaged product and holds the packaged product, comprises a first surface portion, A second surface portion connected to the left front edge portion of the first surface portion via the first folding line portion, a third surface portion connected to the left rear edge portion of the first surface portion via the second folding line portion, A fourth surface connected to the right rear edge of the first surface via a third folding line, and a fifth surface connected to the left front edge of the third surface via a fourth folding line. And a sixth surface portion connected to a left rear edge portion of the fourth surface portion via a fifth folding line portion, and is formed of a single material, and a left front edge portion of the fifth surface portion is formed on the left front edge portion of the fifth surface portion. The second surface portion is formed from the unfolded state in which an engagement protrusion having an inverted trapezoidal planar shape and an engagement recess having a trapezoidal planar shape are formed on the right front edge of the sixth surface portion. Fold Folding at a line portion, overlapping the first surface portion, folding the fifth surface portion at the fourth folding line portion, overlapping the third surface portion, and attaching the sixth surface portion to the fifth folding line portion And the fifth and third superimposed surface portions are folded at the second fold line portion, and the superimposed sixth and fourth surface portions are overlapped with the third surface portion. A cushioning material structure for packing, wherein the structure is assembled by folding at the fold line portion and engaging the engaging protrusion with the engaging concave portion. 4. A packing cushioning material provided at each corner of a packaged object and inserted into the packing box together with the packaged product to hold the packaged product, wherein the cushioning material is a first cushion. A second surface portion connected to the left front edge of the first surface portion via the first folding line portion, and a third surface portion connected to the left rear edge portion of the first surface portion via the second folding line portion. A fourth surface connected to the right rear edge of the first surface via the third folding line, and a fifth surface connected to the left front edge of the third surface via the fourth folding line. A left surface of the fourth surface portion and a sixth surface portion connected to the left rear edge portion of the fourth surface portion via a fifth folding line portion, and a left front edge of the second surface portion. The first engaging recess at the left front edge of the fifth surface, the second engaging projection at the left front edge of the sixth surface, The right front edge of the sixth surface Packaging buffer material, characterized in that it has formed each engaging recess. 5. The planar shape of the first and second engaging concave portions is trapezoidal, and the planar shape of the first and second engaging projections is inverted trapezoidal. 5. The cushioning material for packing according to claim 4, wherein: 6. A packing cushioning material provided at each corner of the packaged object and inserted into the packing box together with the packaged object to hold the packaged object, wherein the cushioning material is a first cushion. A second surface portion connected to the left front edge of the first surface portion via the first folding line portion, and a third surface portion connected to the left rear edge portion of the first surface portion via the second folding line portion. A fourth surface connected to the right rear edge of the first surface via the third folding line, and a fifth surface connected to the left front edge of the third surface via the fourth folding line. A fifth surface portion and a sixth rear surface portion connected to a left rear edge portion of the fourth surface portion via a fifth folding line portion, and a left front edge of the fifth surface portion. A cushioning material for packing, characterized in that an engagement protrusion having an inverted trapezoidal planar shape is formed at the portion, and an engaging recess having a trapezoidal planar shape is formed at the right front edge of the sixth surface portion.