JP7380491B2 - packaging box - Google Patents

Description

The present invention relates to packaging boxes.

The top of the packaging box consists of two top plates connected to the upper edge of the body and arranged in the front-rear direction, and intersecting flaps and engagement plates connected to the upper edge of the body and arranged in the left-right direction. Some devices are equipped with a matching flap (for example, see Patent Document 1).

When the top of the packaging box is closed, the rear part of the cross flap is overlapped with the upper surface of the rear top plate, and the front part of the cross flap is overlapped with the lower surface of the front top plate. In addition, the top can be closed without using adhesive tape or adhesive by placing the engagement flaps on top of both top plates and inserting the insertion part formed on the engagement flap into the connection hole in the top plate. .

JP2019-214420A

The above-mentioned conventional packaging box has a problem in that it is difficult to align the insertion portion and the connection hole when the engagement flaps are stacked on the upper surfaces of both top plates.

An object of the present invention is to solve the above problems and provide a packaging box and a blank sheet whose top can be easily closed and opened.

In order to solve the above-mentioned problem, a first invention is a packaging box, comprising: a cylindrical body having front, left and right wall plates; a bottom that closes a lower opening of the body; and a top provided at the upper opening of the body. The top portion includes a front flap connected to the upper edge of the wall plate on the front side, a rear flap connected to the upper edge of the wall plate on the rear side, and an upper edge of the wall plate on the left side. and a right flap connected to the upper edge of the wall plate on the right side. The right flap overlaps the front flap and the rear flap. The left flap has a rear portion overlapped with an upper surface of the rear flap, and a front portion overlapped with a lower surface of the front flap. The left flap has an inclined edge extending obliquely to the right from the front end of the upper edge of the left wall plate, and a recess is formed in the inclined edge. . The front flap is formed with a main body and a bent portion that overlaps the upper surface of the left flap, and a top fold line is formed at the boundary between the main body and the bent portion. A leading edge portion is formed at the rear left corner of the bent portion along the top fold line.

In order to solve the above-mentioned problem, a second invention is a blank sheet for forming a packaging box, in which four wall plates arranged on the front, rear, left and right sides of the body of the packaging box are arranged in a row in the left-right direction. ing. The blank sheet includes a front flap connected to the upper edge of the wall plate on the front side, a rear flap connected to the upper edge of the wall plate on the rear side, and a rear flap connected to the upper edge of the wall plate on the left side. It includes a left flap connected to the edge, and a right flap connected to the upper edge of the right wall plate. The left flap is formed with a region that overlaps the upper surface of the rear flap and a region that overlaps the lower surface of the front flap when the packaging box is formed. The left flap is formed with an inclined edge extending diagonally upward to the left from the right end of the upper edge of the left wall plate, and a recess is formed in the inclined edge. The front flap has a main body portion and a bent portion. The bent portion is a portion that overlaps the upper surface of the left flap when the packaging box is formed. A top fold line is formed at the boundary between the main body portion and the bent portion. A leading edge portion is formed at the upper left corner of the bent portion along the top fold line.

In the present invention, when closing the top of the packaging box, the front flap and the rear flap are closed, and after the right flap is overlapped with the front flap and the rear flap, the left flap is placed on the upper surface of the front flap and the rear flap. Overlap. Next, the operator inserts his or her finger into the recess from above the left flap and pushes the bent portion downward against the main body of the front flap. Furthermore, the worker's fingers are placed on the tip edge of the folded portion of the front flap, and the folded portion is pulled up above the left flap. Then, the top of the packaging box can be closed by returning the folded portion to the main body and placing the folded portion of the front flap over the upper surface of the left flap.

Further, in the present invention, when opening the top of the packaging box, when the bent portion is pushed downward, the bent portion is bent downward relative to the main body portion and enters below the left flap. This releases the connection between the front flap and the left flap, allowing the top to be opened.

As described above, in the present invention, the top portion can be easily closed by hooking a finger onto the tip end edge of the folded portion of the front flap and pulling up the folded portion. Further, in the present invention, by bending the bent portion of the front flap downward from the top closed state, the bent portion can be pushed into the lower surface side of the left flap, so that the top portion can be easily opened.

In the packaging box described above, the recess can be closed with a lid plate, and a part of the outer edge of the lid plate can be connected to the inner edge of the recess via a fold line.

In the above-described packaging box, the body may form a slanted wall between the adjacent wall plates to form a cylindrical body having a polygonal shape such as a hexagon or an octagon.

In the packaging box described above, the bottom portion includes a front lower flap that is connected to the lower edge of the wall plate on the front side, and a lower front flap that is connected to the lower edge of the left and right wall plates, and a lower surface of the front lower flap. Left and right side lower flaps overlapped with each other are provided. Furthermore, the bottom part includes a rear lower part that is connected to the lower edge of the wall plate on the rear side, is overlapped with the lower surface of the lower flaps on both sides, and has a tip inserted into the inner surface of the front lower flap. Provide a flap.
By closing the bottom using the American lock method in this manner, the bottom can be assembled easily and reliably, and the strength of the bottom can be sufficiently increased without using adhesive tape or adhesive.

In the packaging box and blank sheet of the present invention, the top can be easily closed and opened without using adhesive tape or adhesive.

FIG. 1 is a perspective view of a packaging box according to an embodiment of the present invention, viewed from the front upper right. FIG. 1 is a perspective view of a packaging box according to an embodiment of the present invention, viewed from the front lower right. It is a figure showing a blank sheet of a packaging box concerning an embodiment of the present invention. FIG. 2 is an enlarged perspective view showing a front flap and a left flap of a packaging box according to an embodiment of the present invention. It is a figure showing the procedure of closing the top of the packaging box concerning an embodiment of the present invention, and is an enlarged perspective view of a state where the left flap is overlapped with the upper surface of the front flap and the rear flap. It is a figure which showed the procedure of closing the top part of the packaging box based on embodiment of this invention, and is an enlarged perspective view of the state where the bending part of a front flap was pushed in from the recessed part of a left flap. It is a figure showing the procedure of opening the top of the packaging box concerning an embodiment of the present invention, and is an enlarged perspective view of the state where the bent part of the front flap is pushed in and the left flap is opened.

Embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
In the following description, the front, rear, left, and right directions are set for convenience in explaining the packaging box of this embodiment, and do not limit the configuration or use condition of the packaging box.

As shown in FIG. 1, the packaging box 1 of this embodiment includes a body 10 formed in a hexagonal polygonal tube shape, a bottom 20 that closes an opening on the lower side of the body 10, and a body The top portion 30 closes the upper opening of the portion 10.

The packaging box 1 of this embodiment is formed by mountain-folding or valley-folding a blank sheet S (see FIG. 3) cut out from a corrugated sheet along each fold line. The blank sheet S shown in FIG. 3 is arranged so that the inner surface side is visible.
The fold line of the blank sheet S is a ruled line (pressed line) formed by pressing the surface of the blank sheet S into a linear shape. Note that intermittent cuts may be formed in the ruled lines. This makes it easier to fold the blank sheet S along the fold line.
Alternatively, the folded line may be formed by intermittent half-cut slits that cut only the surface of the sheet or slits that penetrate through the sheet to form a linear shape.

As shown in FIG. 1, the body portion 10 is formed between a pair of front and rear wall plates 11 and 12, a pair of left and right wall plates 13 and 14, and an adjacent front wall plate 11 and a left side wall plate 13. and an inclined wall 16 formed between the adjacent rear wall plate 12 and right side wall plate 14. The front, left, and right wall plates 11 to 14 are formed into a square shape. Hexagonal openings are formed in the upper and lower surfaces of the body 10 in plan view.

Two inclined walls 16, 16 are formed at the front left corner and the rear right corner of the body 10. The left front inclined wall 16 is connected to the left edge of the front wall plate 11 and the front edge of the left wall plate 13 via a fold line. The right rear inclined wall 16 is connected to the right edge of the rear wall plate 12 and the rear edge of the right wall plate 14 via a fold line.
The inclined wall 16 is formed into an elongated rectangle, and the two inclined walls 16, 16 have the same shape. Both inclined walls 16, 16 are inclined with respect to each wall plate 11-14.
In this embodiment, a joint piece 15 is connected to the left edge of the right rear inclined wall 16. The joining piece 15 is joined to the inner surface of the rear wall plate 12.

When the blank sheet S (see FIG. 3) is bent along each fold line and the joint piece 15 is joined to the inner surface of the rear wall plate 12, the front and rear left and right wall plates 11 to 14 and both inclined walls 16, 16 form a Thus, a hexagonal cylindrical body portion 10 is formed.

As shown in FIG. 2, the bottom part 20 includes a front lower flap 21 connected to the lower edge of the front wall plate 11 and a rear lower flap 22 connected to the lower edge of the rear wall plate 12. and a pair of left and right lower side flaps 23, 24 connected to the lower edges of the left and right wall plates 13, 14.

The lower front flap 21 is connected to the lower edge of the front wall plate 11 via a fold line. The front lower flap 21 closes the front half area of the lower opening of the trunk 10.
The left side edge of the front lower flap 21 is formed along the inner surface of the left wall plate 13 and the inner surface of the left front inclined wall 16 (see FIG. 3). Further, the right side edge of the front lower flap 21 is formed along the inner surface of the right wall plate 14.
When the front lower flap 21 is inserted into the lower opening of the trunk 10, the left side edge of the front lower flap 21 contacts the inner surface of the left wall plate 13 and the inner surface of the left front inclined wall 16. At the same time, the right side edge portion is in contact with the inner surface of the right wall plate 14.

The left side lower flap 23 is connected to the lower edge of the left wall plate 13 via a fold line. The front part of the left side lower flap 23 is overlapped with the lower surface of the left part of the front lower flap 21.

The right side lower flap 24 is connected to the lower edge of the right wall plate 14 via a fold line. The front part of the right side lower flap 24 is overlapped with the lower surface of the right part of the front lower flap 21.
The rear edge of the right side lower flap 24 is formed along the inner surface of the rear wall plate 12 and the inner surface of the right rear inclined wall 16 (see FIG. 3).
When the right side lower flap 24 enters the opening on the lower side of the trunk 10, the rear edge of the right side lower flap 24 touches the inner surface of the joint piece 15 and the inner surface of the right rear inclined wall 16. are in contact with each other.
In this embodiment, the rear edge of the right side lower flap 24 is in contact with the inner surface of the joint piece 15, but the rear edge of the right side lower flap 24 is in contact with the inner surface of the rear wall plate 12. They may be configured so that they touch each other.

The rear lower flap 22 is connected to the lower edge of the rear wall plate 12 via a fold line. The rear lower flap 22 is formed into a trapezoidal shape whose width in the left-right direction becomes narrower from the base end (rear end) to the distal end (front end) (see FIG. 3).
The rear lower flap 22 overlaps the lower surfaces of the left and right side lower flaps 23 and 24, and its tip is inserted into the upper surface of the central portion of the front lower flap 21.

The bottom 20 of the packaging box 1 is closed by combining a front lower flap 21, left and right side lower flaps 23, 24, and a rear lower flap 22 in an American locking manner.

As shown in FIG. 1, the top portion 30 includes a front flap 31, a rear flap 32, a left flap 33, and a right flap 34.

The front flap 31 is connected to the upper edge of the front wall plate 11 via a fold line. The front flap 31 closes the front half of the upper opening of the trunk 10.
The rear flap 32 is connected to the upper edge of the rear wall plate 12 via a fold line. The rear flap 32 closes the rear half of the upper opening of the trunk 10.

The right flap 34 is connected to the upper edge of the right wall plate 14 via a fold line. The rear part of the right flap 34 is overlapped with the lower surface of the right part of the rear flap 32. Further, the front part of the right flap 34 is overlapped with the upper surface of the right part of the front flap 31.
In this way, the right flap 34 is connected to the front flap 31 and the rear flap 32 by vertically crossing the front and rear parts of the right flap 34 with respect to the front flap 31 and the rear flap 32. There is.

As shown in FIG. 4, the left flap 33 is connected to the upper edge of the left wall plate 13 via a fold line. The rear part of the left flap 33 is superimposed on the upper surface of the rear flap 32. Further, the front part of the left flap 33 is overlapped with the lower surface of the front flap 31.

As shown in FIG. 5, the left flap 33 includes a proximal edge 33a continuous to the upper edge of the left wall plate 13, and a distal edge 33b parallel to the proximal edge 33a. It includes a rear edge 33c formed along the rear edge of the rear flap 32, and an inclined edge 33d formed from the front end of the distal edge 33b to the front end of the proximal edge 33a. There is.
The leading edge portion 33b is disposed in the rear half of the distance between the front wall plate 11 and the rear wall plate 12 in the front-rear direction. In other words, the tip edge 33b is a portion that overlaps the upper surface of the rear flap 32.

The inclined edge 33d extends diagonally rearward to the right from the front end of the upper edge (base edge 33a) of the left wall plate 13 to the front end of the tip edge 33b. That is, the inclined edge 33d is inclined with respect to the proximal edge 33a so as to move away from the proximal edge 33a to the right as it goes rearward from the front end of the proximal edge 33a.

A recess 33e is formed in the middle of the inclined edge 33d of the left flap 33. The recess 33e is a rectangular depression in the middle of the inclined edge 33d.
Both side edges 33f, 33f and a bottom edge 33g are formed at the inner edge of the recess 33e. At the inner edge of the recess 33e, a corner between the side edge 33f and the bottom edge 33g is curved into an arc.

The recess 33e is closed by the cover plate 35 in the state of the blank sheet S (see FIG. 3). The outer edge of the lid plate 35 is connected to the bottom edge 33g of the recess 33e via a fold line, and is connected to both side edges 33f, 33f of the recess 33e via a slit.

As shown in FIG. 1, the front flap 31 is formed with a main body portion 31a and a bent portion 31b. The bent portion 31b is the rear left corner of the front flap 31, and is a portion that overlaps the upper surface of the left flap 33.

The boundary line between the main body portion 31a and the bent portion 31b is located directly above the inclined edge 33d of the left flap 33, as shown in FIG. That is, in the front flap 31, the part disposed in front of the inclined edge 33d of the left flap 33 is the main body part 31a, and the part disposed behind the inclined edge 33d is the bent part 31b. It has become.

A top fold line L10 is formed at the boundary line between the main body portion 31a and the bent portion 31b. The top fold line L10 is a fold line formed on the lower surface (inner surface) of the front flap 31. In addition, in each figure of this embodiment, in order to make the position of the top polygonal line L10 easy to understand, the top polygonal line L10 is shown on the upper surface (outer surface) of the front flap 31 as a solid line.

A tip edge 31c parallel to the top fold line L10 is formed at the rear left corner of the bent portion 31b. As a result, the bent portion 31b is formed into a trapezoidal shape. The rear left corner of the front flap 31 has a shape cut out diagonally from a right angle.

In the blank sheet S for forming the packaging box 1 of this embodiment, as shown in FIG. ing. In this embodiment, from the left side to the right side of the blank sheet S, the rear wall plate 12, the left wall plate 13, the inclined wall 16, the front wall plate 11, the right wall plate 14, the inclined wall 16, and the joint They are lined up in the order of piece 15.

The blank sheet S includes a front lower flap 21 connected to the lower edge of the front wall plate 11 and a rear lower flap 22 connected to the lower edge of the rear wall plate 12. . The blank sheet S also includes a left side lower flap 23 connected to the lower edge of the left wall board 13 and a right side lower flap 24 connected to the lower edge of the right wall board 14. , is equipped with.

The blank sheet S includes a front flap 31 connected to the upper edge of the front wall plate 11 and a rear flap 32 connected to the upper edge of the rear wall plate 12. The blank sheet S also includes a left flap 33 connected to the upper edge of the left wall plate 13 and a right flap 34 connected to the upper edge of the right wall plate 14. There is.

The left flap 33 has a portion that overlaps the upper surface of the rear flap 32 and a portion that overlaps the lower surface of the front flap 31 when the top portion 30 (see FIG. 4) is formed. The left flap 33 is formed with an inclined edge 33d extending diagonally upward to the left from the right end of the upper edge of the left wall plate 13, and a recess 33e is formed in the inclined edge 33d. .

The front flap 31 is formed with a main body portion 31a and a bent portion 31b. The bent portion 31b is a portion that overlaps the upper surface of the left flap 33 when the top portion 30 (see FIG. 4) is formed.

A top fold line L10 is formed at the boundary between the main body portion 31a and the folded portion 31b, and a tip edge portion 31c parallel to the top fold line L10 is formed at the upper left corner of the folded portion 31b.

Next, a procedure for closing the top portion 30 of the packaging box 1 will be explained.
First, after closing the front flap 31 shown in FIG. 1, the right flap 34 is closed, and the front part of the right flap 34 is overlapped with the upper surface of the right part of the front flap 31.
Subsequently, the rear flap 32 is closed, and the right part of the rear flap 32 is overlapped with the upper surface of the rear part of the right flap 34.
Thereby, the front and rear parts of the right flap 34 vertically intersect with the front flap 31 and the rear flap 32, and the right flap 34 is connected to the front flap 31 and the rear flap 32.

Thereafter, as shown in FIG. 5, the left flap 33 is closed and placed on top of the front flap 31 and the rear flap 32.
Further, as shown in FIG. 6, the operator pushes the lid plate 35 downward with his finger from above the left flap 33, and inserts his finger into the recess 33e.
At this time, the bent portion 31b is pushed downward with respect to the main body portion 31a of the front flap 31 by the lid plate 35, and the bent portion 31b is bent downward with respect to the main body portion 31a. That is, when viewed from the top side, the front flap 31 is mountain-folded at the top fold line L10.

The operator hooks the finger inserted into the recess 33e onto the tip edge 31c of the folded part 31b, and pulls the folded part 31b above the left flap 33.
Thereafter, by flattening the bent portion 31b with respect to the main body portion 31a and stacking the bent portion 31b on the upper surface of the left flap 33, the top portion 30 of the packaging box 1 can be closed, as shown in FIG. .

Next, when opening the top part 30 of the packaging box 1, the bent part 31b is pushed downward, as shown in FIG. In this way, the bent portion 31b is bent downward with respect to the main body portion 31a, and enters below the left flap 33. In other words, the bent portion 31b is bent into a mountain fold when viewed from above, thereby avoiding the inclined edge 33d of the left flap 33 and moving below the left flap 33. At this time, since the recess 33e is formed in the inclined edge 33d of the left flap 33, the bent portion 31b can easily move downward avoiding the inclined edge 33d.
This releases the connection between the front flap 31 and the left flap 33, so the rear flap 32, the right flap 34 (see FIG. 1), and the front flap 31 can be opened in this order to open the top 30. can.

In the packaging box 1 and blank sheet S as described above, as shown in FIG. On the other hand, the bent portion 31b is bent downward. Then, the top portion 30 can be easily closed by hooking a finger onto the tip edge 31c of the bent portion 31b and pulling up the bent portion 31b.

Note that when pushing in the lid plate 35 of the left flap 33 and inserting the operator's finger into the recess 33e, the corner between the side edge 33f and the bottom edge 33g of the recess 33e is formed into an arc shape. Therefore, it is possible to prevent the left flap 33 from tearing from the corner of the recess 33e.

In the packaging box 1 and blank sheet S of this embodiment, as shown in FIG. 7, when opening the top portion 30, when the bent portion 31b is pushed downward, the bent portion 31b is bent downward relative to the main body portion 31a. Since it enters below the left flap 33, the top portion 30 can be opened easily. At this time, the bent portion 31b tends to move downward avoiding the inclined edge 33d where the recessed portion 33e is formed. In this way, when the front flap 31 is pushed downward, the front flap 31 is mountain-folded at the top fold line L10, and the bent portion 31b and the inclined edge 33d of the left flap 33 are switched vertically, so that the left flap 33 can be opened (launched) easily.

In this way, in the packaging box 1 and blank sheet S of this embodiment, the top portion 30 can be easily closed and opened without using adhesive tape or adhesive.

Furthermore, in the packaging box 1 and blank sheet S of this embodiment, the bottom portion 20 is closed using the American lock method, as shown in FIG. Therefore, the bottom part 20 can be assembled easily and reliably, and the strength of the bottom part 20 can be sufficiently increased without using adhesive tape or adhesive.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be modified as appropriate without departing from the spirit thereof.
In this embodiment, as shown in FIG. 5, the recess 33e of the left flap 33 is closed by the cover plate 35, but the recess 33e does not need to be closed by a cover plate or the like.

In this embodiment, as shown in FIG. 1, the top portion 30 is formed by stacking a front flap 31, a right flap 34, a rear flap 32, and a left flap 33 in this order. However, the configuration in which the right flap 34 overlaps the front flap 31 and the rear flap 32 is not limited.

In this embodiment, the front flap 31 and the rear flap 32 are butted against each other, but by arranging the front flap 31 and the rear flap 32 with an interval in the front-rear direction, an opening is formed in the center of the top 30. It is also possible to form a section.

The width and height of each of the wall plates 11 to 14 and the inclined wall 16 of the packaging box 1 are not limited. Furthermore, the number of inclined walls 16 is not limited either. Furthermore, the angle of inclination of the inclined wall 16 with respect to each of the wall plates 11 to 14 is not limited.
For example, each of the wall plates 11 to 14 and both inclined walls 16, 16 of the packaging box 1 may be formed to have the same width, and the body portion 10 may be formed into a regular hexagon.

In this embodiment, the sloping wall 16 is provided on the body 10, but a rectangular body may be formed by the front, rear, left, and right wall plates 11 to 14 without providing the slant wall 16 on the body 10. .

Although the packaging box 1 and blank sheet S of this embodiment are made of corrugated cardboard, the packaging box 1 can be made of various known paperboards.

1 Packaging box 10 Body 11 Front wall plate 12 Rear wall plate 13 Left side wall plate 14 Right side wall plate 15 Joint piece bottom 16 Slanted wall 20 Bottom 21 Front lower flap 22 Rear lower flap 23 Left side lower flap 24 Right side lower flap 30 Top part 31 Front flap 31a Main body part 31b Bend part 31c Tip edge 32 Rear flap 33 Left flap 33a Base edge 33b Tip edge 33c Rear edge 33d Slanted edge 33e Recessed part 33f Side Edge 33g Bottom edge 34 Right flap 35 Lid plate L10 Top fold line S Blank sheet

Claims (5)

A cylindrical body having front, left and right wall plates;
a bottom portion that closes an opening on the lower side of the body;
a top provided in the upper opening of the body;
The top part is
a front flap connected to the upper edge of the wall plate on the front side;
a rear flap connected to the upper edge of the wall plate on the rear side;
a left flap connected to the upper edge of the left wall plate;
a right flap connected to the upper edge of the wall plate on the right side;
the right flap overlaps the front flap and the rear flap;
The left flap has a rear portion overlapped with the upper surface of the rear flap, and a front portion overlapped with the lower surface of the front flap,
The left flap is formed with an inclined edge extending diagonally rearward from the front end of the upper edge of the wall plate on the left side, and a recess is formed in the inclined edge. ,
The front flap is formed with a main body portion and a bent portion that overlaps the upper surface of the left flap,
A top fold line is formed at the boundary between the main body portion and the bent portion,
A packaging box characterized in that a leading end edge is formed at the rear left corner of the folded portion along the top fold line. The packaging box according to claim 1,
The packaging box is characterized in that the recess is closed by a lid plate, and a part of the outer edge of the lid plate is connected to the inner edge of the recess via a fold line. The packaging box according to claim 1 or claim 2,
The packaging box is characterized in that the body portion includes an inclined wall formed between the adjacent wall plates. The packaging box according to any one of claims 1 to 3,
The bottom part is
a lower front flap connected to the lower edge of the wall plate on the front side;
left and right side lower flaps that are connected to the lower edges of the left and right wall plates and overlapped with the lower surfaces of the front lower flaps;
a rear lower flap that is connected to the lower edge of the wall plate on the rear side, is overlapped with the lower surface of the lower flaps on both sides, and has a tip inserted into the inner surface of the front lower flap. A packaging box characterized by: A blank sheet for forming a packaging box,
Four wall plates arranged on the front, rear, left and right sides of the body of the packaging box are connected in the left and right direction,
a front flap connected to the upper edge of the wall plate on the front side;
a rear flap connected to the upper edge of the wall plate on the rear side;
a left flap connected to the upper edge of the left wall plate;
a right flap connected to the upper edge of the wall plate on the right side;
The left flap is formed with a region that overlaps the upper surface of the rear flap and a region that overlaps the lower surface of the front flap when the packaging box is formed,
The left flap is formed with an inclined edge extending diagonally upward to the left from the right end of the upper edge of the left wall plate, and a recess is formed in the inclined edge;
The front flap has a main body portion and a bent portion,
The bent portion is a portion that overlaps the upper surface of the left flap when the packaging box is formed,
A top fold line is formed at the boundary between the main body portion and the bent portion,
A blank sheet characterized in that a leading edge portion is formed at the upper left corner of the folded portion along the top fold line.

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