JP2022151081A - paper container - Google Patents

Abstract

To provide a paper container capable of preventing warpage of the container due to folding back as much as possible.SOLUTION: A paper container is a paper container assembled from a paper blank sheet, and has a bottom surface part, a plurality of side surface parts rising from the bottom surface part, and a plurality of flange parts forming an upper surface by being bent outward from an end part of the plurality of side surface parts opposite to the bottom surface part. At least one flange part among the plurality of flange parts has a corner connection piece at an end part in a longitudinal direction for connection with another flange part. An inclination folding part or inclination cutting part is formed between the corner connection piece and the side surface part adjacent to the corner connection piece, wherein folding parts between the plurality of side surface parts and the plurality of flange parts are inclined at a predetermined angle toward the bottom surface part.SELECTED DRAWING: Figure 9

Description

The present invention relates to paper containers assembled from blank sheets, for example for packaging foodstuffs and the like.

Tray-like containers assembled from blank sheets of paper and having a flange on the upper end are known.

For example, Patent Document 1 below describes a paper container assembled from paper blank sheets and having an octagonal flat outer end, in which flanges are formed on the upper ends of four sides other than the sides located at the four corners. A pair of corner pieces projecting outward from a pair of left and right sides of the side surface are formed at the left and right ends of the piece, and the pair of corner pieces are bonded to each other by arc-shaped corner lower pieces at the upper ends of the four corner side surfaces. is described as being connected.

JP 2019-172339 A

However, in the technique described in Patent Literature 1, after the paper container is assembled, a pair of corner pieces at the corners of the container, in particular, generate a force that tends to return the container in a direction opposite to the direction in which the container was folded. warpage may occur.

SUMMARY OF THE INVENTION In view of the circumstances as described above, an object of the present invention is to provide a paper container that can prevent warping of the container due to unfolding as much as possible.

In order to achieve the above object, a paper container according to one aspect of the present invention is a paper container assembled from paper blank sheets, comprising: a bottom portion; a plurality of side portions rising from the bottom portion; and a plurality of flange portions forming an upper surface by bending outward from ends of the plurality of side portions opposite to the bottom portion.
At least one of the plurality of flanges has a corner connecting piece at its longitudinal end for connection with another flange.
Between the corner connection piece and the side surface portion adjacent to the corner connection piece, there is an inclined fold inclined at a predetermined angle toward the bottom surface portion from the fold between the plurality of side surface portions and the plurality of flange portions. Alternatively, an oblique cut is formed.

With this configuration, the paper container has an inclined fold portion or an inclined cut portion between the corner connection piece and the side portion, so that it can be folded at the fold between the flange portion and the side portion or The corner connecting piece can be brought closer to the flange part side of the connection destination at the time of assembly as compared with the case of cutting on the extension line of , thereby preventing warping of the container due to bending back of the corner connecting piece as much as possible. Here, the predetermined angle is, for example, about 1 degree to 5 degrees, but is not limited to this.

The bottom portion may be formed in an octagonal shape in plan view so as to have a pair of long sides, a pair of short sides and two pairs of corner sides. In this case, the plurality of side portions include a pair of long side portions rising from the pair of long sides, a pair of short side portions rising from the pair of short sides, and two pairs of corners rising from the two pairs of corner sides. and the plurality of flange portions are composed of a pair of long flange portions corresponding to the pair of long side portions, a pair of short flange portions corresponding to the pair of short side portions, and the two pairs of There may be two pairs of corner flange portions corresponding to the corner side portions. In this case, the corner connecting pieces are formed at both ends in the longitudinal direction of the pair of long flanges and the pair of short flanges, and are adhered to the rear surfaces of the two pairs of corner flanges.

Thereby, it is possible to prevent bending back as much as possible when each corner flange portion and each corner connection piece of two adjacent flange portions are connected.

The inclined fold portion or the inclined cut portion is located at the long flange portion and the short flange portion from the intersection of the extension line of the fold and the extension line of each side of the long side portion and the short side portion. It may have its starting end on the inside.

As a result, the corner connecting piece can be brought closer to the corner flange portion during assembly by making the corner connecting piece closer to the corner flange portion during assembly by making the long side portion and the short side portion slanted from the ridgeline between the long side portion and the short side portion and the corner side portion. can be formed, and the bending return can be further prevented.

The corner connecting piece may have a narrow portion defined by the inclined fold portion or the inclined cut portion, and a wide portion extending from the narrow portion and positioned on the rear surface of the corner flange portion. .

At the upper ends of both sides of the long side portion or the short side portion, there is a height equal to the width difference between the narrow portion and the wide portion, and when stacking a plurality of paper containers, the height is equal to the height of the difference between the paper containers. It may further have a stacking rib forming a gap corresponding to the height.

As a result, it is possible to effectively utilize the remaining piece of the corner connecting piece formed with the wide portion and the narrow portion as a stacking rib.

In the blank sheet, portions surrounded by the corner side portions, the corner connecting pieces, the long side portions or the short side portions are connected to the corner side portions and the corner connecting pieces and the long side portions. It may be cut along the shape of the side portion or the short side portion.

As a result, when the blank sheet is formed, the portion surrounded by the corner side portion, the corner connection piece, and the long side portion or the short side portion is left connected to the corner side portion without punching, and wasteful punching residue is generated. It is possible to improve the strength of the corner portion of the container while preventing the occurrence.

An end portion of the corner flange portion opposite to the corner side portion may have an R shape with a first radius of curvature and is opposite to the long side portion or the short side portion of the corner connecting piece. The side end may have an R shape with a second radius of curvature that is the same or substantially the same as the first radius of curvature.

As a result, by matching the R shape of the corner connection piece with the R shape of the corner flange portion, even if there is some misalignment in alignment when the corner connection piece is adhered to the corner flange portion, the misalignment can be corrected. can be made inconspicuous.

As described above, according to the present invention, it is possible to prevent warping of a paper container due to unfolding as much as possible. However, this effect does not limit the invention.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan side perspective view showing the appearance of a paper container according to one embodiment of the present invention; FIG. 2 is a bottom perspective view of the paper container of FIG. 1; FIG. 2 is a front view of the paper container of FIG. 1; FIG. 2 is a side view of the paper container of FIG. 1; FIG. 2 is a plan view of the paper container of FIG. 1; FIG. 2 is a bottom view of the paper container of FIG. 1; FIG. 3 is an exploded view showing a blank sheet of the paper container; 3 is an enlarged view of part A of the paper container of FIG. 2. FIG. FIG. 8 is an enlarged view of the B portion of the blank sheet of FIG. 7; It is the figure which showed notionally a mode that the inclination crease|fold part of the said blank sheet is bent.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Overview of paper containers]
FIG. 1 is a plan side perspective view showing the appearance of a paper container according to one embodiment of the present invention. 2 is a bottom side perspective view of the paper container of FIG. 1. FIG. 3 is a front view of the paper container, FIG. 4 is a side view of the paper container, FIG. 5 is a plan view of the paper container, and FIG. 6 is a bottom view of the paper container. is. FIG. 7 is an exploded view showing a blank sheet before assembling the paper container.

As shown in each figure, the paper container 100 according to the present embodiment is formed by folding a blank sheet 50 made of paper (for example, cardboard) by a box making machine (case former) or the like, and is It is a container assembled into a rectangular tray with an open top. Of course, the shape of the paper container 100 is not limited to a rectangle, and may be another polygonal shape as long as it has a bottom surface, side surfaces rising from the bottom surface, and an open top surface.

As shown in each figure, the paper container 100 includes a bottom portion 1, a plurality of side portions 2 (2a, 2b, 2c) rising from the bottom portion 1, and the plurality of side portions 2 connected to each other. It has a rectangular frame-shaped flange portion 3 positioned at the upper end of the entire container.

The bottom portion 1 is formed in an octagonal shape in plan view so as to have a pair of long sides, a pair of short sides and two pairs of corner sides. In the blank sheet 50, corresponding to the pair of long sides, the pair of short sides and the two pairs of corner sides, a first fold 4a and a pair of folds 4b are formed by, for example, a perforation blade. and two pairs of folds 4c are formed. By each of the folds 4, as the side portions 2, a pair of long side portions 2a rising from a pair of long sides of the bottom portion 1, a pair of short side portions 2b rising from a pair of short sides, and two pairs rising from two corner pieces. A pair of corner side portions 2c are formed.

As shown in FIGS. 1 to 4, each side surface portion 2 protrudes outward from the outer edge of the bottom surface portion 1 and forms a tapered surface (inclined surface) that is inclined with respect to the bottom surface portion 1 . However, it does not matter if the side part 2 is perpendicular to the bottom part 1 .

The flange portion 3 includes a pair of long flange portions 3a corresponding to the pair of long side portions 2a, a pair of short flange portions 3b corresponding to the pair of short side portions 2b, and the two pairs of corner side portions 2c. and two pairs of corner flange portions 3c corresponding to .

As shown in FIGS. 1, 2, 5, 6 and 7, each flange 3 corresponds to each fold 5 of the blank sheet 50 (5a corresponding to the long side 2a and short side 2b). 5b and 5c) corresponding to the corner side portions 2c are formed so as to protrude substantially horizontally outward from the upper end of each side portion 2. As shown in FIG.

Among them, the long flange portion 3a and the short side portion 3b are formed in a rectangular shape, and the corner flange portion 3c is formed in a semicylindrical shape with an arcuate outer side. However, the shape of the corner flange portion 3c is not limited to this.

As shown in FIGS. 2, 6 and 7, the long flange portion 3a and the short flange portion 3b protrude from both ends in the longitudinal direction (X direction and Y direction) of the corners. It has a cantilever-shaped corner connection piece 31 that connects with the flange portion 3c. Specifically, a pair of corner connection pieces 31 protruding from adjacent ends of the adjacent long flange portion 3a and short flange portion 3b are adhered to the back surfaces of the respective corner flange portions 3c, thereby forming the long flange portion 3a and the short flange portion 3b. The short flange portion 3b and the corner flange portion 3c are connected.

In addition, as shown in FIGS. 2 to 4 and 6, at both upper ends of the long side portion 2a and the short side portion 2b, when stacking a plurality of the paper containers 100, there is a gap between the paper containers 100. A total of eight stacking ribs 22 are provided to form a predetermined gap to facilitate gripping.

As shown in FIGS. 2, 6 and 7, the outer end portion of the corner flange portion 3c (the end portion opposite to the corner side portion 2c) has an R shape with a predetermined radius of curvature. On the other hand, the outer end portion of the corner connecting piece 31 (the end portion opposite to the long side portion 2a and the short side portion 2b) also has an R shape with the same or substantially the same radius of curvature as the corner flange portion 3c. is doing.

As a result, by matching the R shape of the corner connecting piece 31 and the R shape of the corner flange portion 3c, even if there is some misalignment when the corner connecting piece 31 is adhered to the corner flange portion 3c, , the deviation can be made inconspicuous.

After assembly, the inner surface of the paper container 100 may be covered with a resin film. In this case, the resin film is a single-layer or multi-layer film made of a thermoplastic resin that can be welded to the inner surface of the paper container 100 and has a thickness of about 50 to 500 μm. It has a function to prevent leakage to the outside.

Examples of thermoplastic resins include polyethylene (PE), polypropylene (PP), polyvinyl chloride, polyethylene terephthalate (PET), ethylene-vinyl acetate copolymer (EVA), and the like. Considering that the paper container 100 is separated from the paper container 100 after use and discarded, a film having an easy peel property is preferable. This resin film is applied to the paper container 100 at a predetermined temperature by suction pressure bonding, for example, by forming a vacuum pressure.

[Blank sheet]
Next, the blank sheet 50 will be described with reference to FIG.

As shown in FIG. 7, in the center of the bran sheet 50, there is the above-described octagonal bottom surface portion 1 which becomes the bottom surface of the paper container 100 after assembly. Then, from the bottom surface portion 1, the long side portion 2a of the inverted trapezoid is outside the fold 4a of the long side, the short side portion 2b of the inverted trapezoid is outside the fold 4b of the short side, and the fold of the oblique side. Rectangular corner side portions 2c are formed outside the eyes 4c.

Furthermore, the long flange portion 3a extends from the long side portion 2a to the outside of the fold 5a, the short flange portion 3b extends from the short side portion 2b to the outside of the fold 5b, and the corner side portion 2c extends to the outside of the fold 5c. The corner flange portions 3c are formed respectively.

At both ends of the long flange portion 3a and the short flange portion 3b, the above-described corner connecting pieces 31 are formed over the boundary with each corner flange portion 3c.

Here, in the blank sheet 50, the triangular portion 21 surrounded by the corner side portion 2c, the corner connection piece 31, and the long side portion 2a or the short side portion 2b (including the stacking rib 22) is It is cut along the shape of the corner connecting piece 31 and the long side portion 2a or the short side portion 2b while being connected to the side portion 2c. As shown in FIGS. 1 and 5, during assembly, the portions 21 are positioned so as to overlap both side ends of the long side portion 2a or the short side portion 2b, and function as side reinforcing portions 21. As shown in FIGS. The portion 21 may be adhered to both side ends of the long side portion 2a or the short side portion 2b with glue or the like. Further, the resin film may be integrally covered with the both side ends of the long side portion 2a or the short side portion 2b so as to be overlapped with each other so as to be fixed to the both side portions.

Thus, when forming the blank sheet 50, the portion 21 surrounded by the corner side portion 2c, the corner connecting piece 31, and the long side portion 2a or the short side portion 2b is connected to the corner side portion 2c without punching. To improve the strength of the corner portion of the paper container 100 while preventing the generation of wasteful cut-out scum by leaving it as it is and adhering it to the long side portion 2a or the short side portion 2b when assembling the paper container 100. - 特許庁can be done.

[Corner connection piece and slanted line portion for preventing bending back]
Next, the details of the corner connection piece 31 and the inclined line portions formed between the corner connection piece 31 and the long side portion 2a and the short side portion 2b will be described.

FIG. 8 is an enlarged view of the dashed-dotted circle A portion of the paper container 100 of FIG. FIG. 9 is an enlarged view of the dashed-dotted line circle B portion of the blank sheet 50 of FIG.

As shown in these figures, between the corner connecting piece 31 and (the stacking ribs 22 of) the long side portion 2a and the short side portion 2b adjacent to the corner connecting piece 31, the long side portion 2a and the short side portion An inclined line portion 7 inclined at a predetermined angle toward the bottom portion 1 is formed from the folding line 5a between the portion 2b and the long flange portion 3a and the short flange portion 3b.

Although the details will be described later, the inclined line portion 7 is formed by bending the corner connecting piece 31 after the corner connecting piece 31 is folded at the crease 5a and adhered to the corner blank portion 3c when the paper container 100 is assembled. It is provided to prevent the paper container 100 from being warped due to the generation of a force to return in the direction opposite to the direction (folding return).

As shown in FIG. 9, the inclined line portion 7 is based on the intersection point P between the extension line of the cut side of the long side portion 2a (and the short side portion 2b) of the blank sheet 50 and the fold line 5a (and 5b). , has its starting end at a predetermined distance inwardly along the fold 5a (and fold 5b).

More specifically, the inclination angle is, for example, 4 degrees, but is not limited to this, and can be changed as appropriate depending on the size of the paper container 100 and each part. Further, even if the paper container 100 has the same size as the present embodiment, the inclination angle can be changed within the range of 1 degree to 5 degrees, for example. If the angle of inclination is less than 1 degree, the effect of preventing bending back cannot be obtained. This is because there may be gaps between them, or they may be easily damaged after adhesion.

Although the predetermined distance is 7.5 mm, it is not limited to this, and can be appropriately changed depending on the size of the paper container 100 and each part. Further, even if the paper container 100 has the same size as the present embodiment, the predetermined distance can be changed within the range of 3 mm to 15 mm, for example. Although this depends on the relationship with the inclination angle, when the predetermined distance is smaller than 3 mm and the start end of the inclined line portion 7 is positioned further outward, the effect of preventing bending back cannot be obtained. This is because, if the predetermined distance is greater than 15 mm and the start end of the inclined line portion 7 is positioned further inside, the effect of preventing the bending from returning may become excessive.

The inclined line portion 7 is composed of an inclined fold portion 7a, which is a fold formed by a perforating blade from the start end to the vicinity of the intersection point P, and a cut portion formed after the end of the inclined fold portion 7a. It is composed of a certain inclined cut portion 7b. The inclined cut portion 7 b forms the upper side of the stacking rib 22 .

The corner connecting piece 31 includes a narrow portion 31a defined by the inclined line portion 7 and the outer edges of the long flange portion 3a and the short flange portion 3b facing the inclined line portion 7, and a corner flange extending from the narrow portion 31a. and a wide portion 31b adhered to the rear surface of the portion 3c.

As shown in FIGS. 8 and 9, the stacking rib 22 has a height equal to the width difference between the narrow portion 31a and the wide portion 31b. That is, the leftover piece of the corner connecting piece 31 formed with the narrow portion 31 a and the wide portion 31 b can be effectively utilized as the stacking rib 22 .

FIG. 10 is a diagram conceptually showing how the inclined line portion 7 is folded in the blank sheet 50 in comparison with the case where the inclined line portion 7 is not provided. 4A shows the case where the slanted line portion 7 is not provided, and FIG. 4B shows the case where the slanted line portion 7 is provided.

As shown in FIG. 1A, when the inclined line portion 7 is not provided, the flange portion 3 is naturally bent linearly along the linear fold 5 with respect to the side portion 2 .

On the other hand, when the inclined line portion 7 is provided as shown in FIG. At the inclined fold portion 7a of the line portion 7, it is bent obliquely downward (toward the bottom surface portion 1) along the inclination angle.

As a result, the corner flange portion 3c can be brought closer to the corner connecting piece 31 during assembly, thereby preventing the paper container 100 from warping due to the bending back of the corner connecting piece 31 as much as possible.

In particular, in the inclined line portion 7, as described above, the cut sides of the long side portion 2a or the short side portion 2b of the blank sheet 50 (between the long side portion 2a and the short side portion 2b and the corner side portion 2c) The corner flange portion 3c can be brought closer to the corner connecting piece 31 side during assembly by making an inclination from the inner side (long side portion 2a and short side portion 2b side) of the ridgeline), thereby further preventing the above-mentioned bending back. can be done.

[Modification]
The present invention is not limited to the above-described embodiments, and can be modified in various ways without departing from the gist of the present technology.

The length ratio between the inclined fold portion 7a and the inclined cut portion 7b of the inclined line portion 7 in the above-described embodiment is not limited to the illustrated one, and can be changed as appropriate. Further, in the above-described embodiment, the inclined line portion 7 is formed by the inclined fold portion 7a and the inclined cut portion 7b, but the entire inclined line portion 7 may be formed by the inclined fold portion. That is, the inclined fold portion 7a may be provided over the entire upper side of the stacking rib 22 (to the front of the R portion).

The size and shape of the paper container 100 shown in the above embodiment are not limited to those illustrated. In the above-described embodiment, the paper container 100 has an octagonal bottom when viewed from above, but the shape of the container is not limited to this. For example, the bottom surface may be a polygon such as a quadrangle, a hexagon, or the like in plan view. For example, in a rectangular container, the corner connecting pieces are provided at one end in the longitudinal direction of the four flanges corresponding to the four sides of the plane, and are connected to adjacent flanges during assembly. Depending on the shape of the container, the shape and size of the inclined line portion 7, the angle of inclination, the position of the starting point, etc. may be changed as appropriate.

DESCRIPTION OF SYMBOLS 1... Bottom part 2a... Long side part 2b... Short side part 2c... Corner side part 3a... Long flange part 3b... Short flange part 3c... Corner flange part 4a, 4b, 4c... Fold 5a, 5b, 5c... Fold 7... Inclined line part 7a... Inclined fold part 7b... Inclined cut part 21... Side reinforcement part 22... Stacking rib 31... Corner connecting piece 31a... Narrow width part 31b... Wide width part 50... Blank sheet 100... Paper container

Claims (7)

A paper container assembled from paper blank sheets, comprising:
a bottom portion, a plurality of side portions rising from the bottom portion, and a plurality of flange portions forming an upper surface by bending outward from ends of the plurality of side portions opposite to the bottom portion; ,
at least one of the plurality of flanges has a corner connection piece at its longitudinal end for connection with another flange;
Between the corner connection piece and the side surface portion adjacent to the corner connection piece, there is an inclined fold inclined at a predetermined angle toward the bottom surface portion from the fold between the plurality of side surface portions and the plurality of flange portions. A paper container in which a part or an oblique cut is formed. The paper container according to claim 1,
The bottom portion is formed in an octagonal shape in plan view so as to have a pair of long sides, a pair of short sides and two pairs of corner sides,
The plurality of side portions are composed of a pair of long side portions rising from the pair of long sides, a pair of short side portions rising from the pair of short sides, and two pairs of corner side portions rising from the two pairs of corner sides. has
The plurality of flange portions include a pair of long flange portions corresponding to the pair of long side portions, a pair of short flange portions corresponding to the pair of short side portions, and two pairs of corner side portions corresponding to the two pairs of corner side portions. and a pair of corner flanges,
The corner connection piece is formed at each of the longitudinal ends of the pair of long flanges and the pair of short flanges, and is adhered to the rear surface of each of the two pairs of corner flanges. The paper container according to claim 2,
The slanted fold or slanted cut is located at the long flange and the short flange from the intersection of the extension of the fold and the extension of each side of the long side and the short side. A paper container having its starting end inside. The paper container according to claim 3,
The corner connecting piece has a narrow portion defined by the inclined fold portion or the inclined cut portion, and a wide portion extending from the narrow portion and positioned on the back surface of the corner flange portion. The paper container according to claim 4,
The upper ends of both sides of the long side portion or the short side portion have a height corresponding to the difference in width between the narrow portion and the wide portion, and when stacking a plurality of paper containers, the height is equal to the difference between the widths of the paper containers. paper container further comprising stacking ribs forming a corresponding gap. The paper container according to any one of claims 2 to 5,
In the blank sheet, a portion surrounded by each of the corner side portions, the corner connection piece, and the long side portion or the short side portion is connected to the corner side portion and the corner connection piece and the long side portion. A paper container that is cut along the shape of the side portion or the short side portion. The paper container according to any one of claims 2 to 6,
an end portion of the corner flange portion opposite to the corner side portion has an R shape with a first curvature radius;
An end portion of the corner connecting piece opposite to the long side portion or the short side portion has an R shape with a second radius of curvature that is the same or substantially the same as the first radius of curvature.

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