Container

Abstract

To provide a container having high shape retention.SOLUTION: A container according to one embodiment comprises: a bottom wall part including a pair of base parts and a partition; a side wall part including a plurality of side wall pieces erected from an outer edge of the bottom wall part, which defines a storage space together with the bottom wall part; a flange part including a plurality of flange pieces expanding from upper ends of the plurality of side wall pieces to the outside; a panel connected to the partition; and a panel flange expanding from an upper end of the panel to the outside. The partition has a first surface erected from either of the pair of base parts, a second surface erected from the other of the pair of base parts and a third surface connecting the first surface to the second surface, which partitions the storage space into a plurality of small spaces. The panel extends from the third surface of the partition. A pair of adjacent flange pieces of the plurality of flange pieces are joined to each other so as to overlap with the panel flange.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] SUMMARY The present disclosure relates to containers formed by folding a blank sheet having a paper substrate. [Background technology]

[0002] Conventionally, paper containers for containing contents such as food have been widely used. For example, Patent Document 1 describes a paper tray that includes a bottom surface, side panels that are raised so as to surround the bottom surface, and edge pieces that are continuous with the upper ends of the side panels, and in which adjacent side panels and adjacent adjacent edge pieces are sealed and connected with a thermoplastic resin layer.

[0003] Patent Documents 2 to 4 disclose a tray with a film formed by folding a blank sheet of paper and having its inner surface covered with a film. This tray includes a container body having a bottom wall and a plurality of side walls defining a large storage space therein, and a partition dividing the large storage space into two or more small storage spaces. The edges of a pair of adjacent side walls of the container body are butted against each other and are held upright against the bottom wall by a film that straddles the edges of the pair of side walls. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-155104 [Patent Document 2] JP 2023-007887 A [Patent Document 3] JP 2023-007888 A [Patent Document 4] JP 2023-007889 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the film-attached trays described in Patent Documents 2 to 4, the edges of a pair of side walls are butted against each other, and the shape is maintained by the film that straddles the edges of the pair of side walls, so that a locally low-rigidity area where no paper base material is arranged is formed at the boundary between the edges of the pair of side walls. Therefore, this tray is easily folded from the boundary, and the container has difficulty in retaining its shape. In particular, when a blank sheet is folded to form a container having a partition, a restoring force acts on the container to return it to its original shape. If the container has low shape retention, this restoring force causes the bottom wall to warp, and the corners of the bottom wall may rise up from the placement surface. The rising up of the bottom wall reduces the stability of the tray.

[0006] Therefore, an object of the present disclosure is to provide a container having high shape retention. [Means for solving the problem]

[0007] In one embodiment, a container is provided by folding a blank sheet having a paper base material, the container comprising: a bottom wall including a plurality of bases and a partition; a side wall including a plurality of side wall pieces erected from an outer edge of the bottom wall and defining a storage space together with the bottom wall; a flange having a plurality of flange pieces extending outward from upper ends of the side wall pieces; a panel connected to the partition; and a panel flange extending outward from the upper end of the panel, the partition having a first surface extending from a first base of the plurality of bases, a second surface extending from a second base of the plurality of bases, and a third surface connecting the first surface and the second surface, dividing the storage space into a plurality of small spaces, the panel extending from the third surface of the partition, and a pair of adjacent flange pieces of the plurality of flange pieces being joined in an overlapping state to the panel flange.

[0008] In the container according to the above aspect, the pair of flange pieces are joined to the panel flange in an overlapping state. This allows the joint between the pair of flange pieces to be supported by the panel connected to the panel flange, improving the rigidity of the joint between the pair of flange pieces. This improves the shape retention of the container. As a result, the corners of the bottom wall are prevented from floating.

[0009] In one embodiment, the blank sheet has a resin film laminated on a paper base material, and the pair of flange pieces may be joined to the panel flange by fusing the resin film folded between each of the pair of flange pieces and the panel flange. In this embodiment, the pair of flange pieces can be joined with high rigidity, thereby improving the shape retention of the container.

[0010] In one embodiment, the pair of flange pieces may be bonded to the panel flange by an adhesive. In this embodiment, the pair of flange pieces can be joined with high rigidity, thereby improving the shape retention of the container.

[0011] In one embodiment, the blank sheet includes a bottom wall sheet portion that forms a bottom wall portion when folded into the shape of the container, a side wall sheet portion that forms a side wall portion and a flange portion when folded into the shape of the container, and a panel sheet portion that forms a panel and a panel flange when folded into the shape of the container, and the bottom wall sheet portion has a first fold line, a second fold line, a third fold line, and a fourth fold line that extend parallel to each other in a first direction and are arranged in this order in a second direction perpendicular to the first direction to form a partition, and the panel sheet portion may be connected to a region between the second fold line and the third fold line of the bottom wall sheet portion and extend from the region in the first direction. By folding the bottom wall sheet portion along the first fold line, the second fold line, the third fold line, and the fourth fold line, a partition that divides the storage space into a plurality of small spaces can be formed. As a result, a plurality of contents can be individually stored in the small spaces.

[0012] In one embodiment, the width of the panel sheet portion in the second direction may be equal to or less than the width of the region in the second direction. By making the width of the panel sheet portion equal to or less than the width of the region between the second fold line and the third fold line of the bottom wall sheet portion, interference between the side wall sheet portion and the panel sheet portion can be suppressed when the blank sheet is folded to form a container.

[0013] In one embodiment, the panel sheet portion may have a rectangular shape. In another embodiment, the panel flange may be joined to the pair of flange pieces in a state where the panel flange is overlapped from the lower surface side of the pair of flange pieces. In this embodiment, the pair of flange pieces can be joined with high rigidity.

[0014] In one embodiment, the height of the third surface based on the multiple bases may be 75% or less of the height of the flange portion based on the multiple bases. If the height of the third surface (partition height) is high, the restoring force acting on the container increases, making it easier for warping to occur in the bottom wall portion. In contrast, by setting the height of the third surface to 75% or less of the height of the flange portion, warping of the bottom wall portion can be suppressed.

[0015] In one embodiment, the panel may be folded along a fold line formed between the outer edge of the bottom wall portion and the panel flange. When the pair of flange pieces are joined to the panel flange by fusing the resin film folded between each of the pair of flange pieces and the panel flange, depending on the position of the fold line of the panel, the resin film may be loose or taut, and the resin film may not be neatly folded between each of the pair of flange pieces and the panel flange. In contrast, by folding the panel along the fold line formed between the outer edge of the bottom wall portion and the panel flange, the resin film can be neatly folded between each of the pair of flange pieces and the panel flange. Effect of the Invention

[0016] According to the present disclosure, the shape retention of a container can be improved. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view of a container according to one embodiment. [Diagram 2] FIG. 2 is an enlarged side view of the container showing the periphery of the panel. [Diagram 3] FIG. 2 is a plan view of a blank sheet for producing the container shown in FIG. [Figure 4]FIG. 13 is a perspective view of a container according to another embodiment. [Diagram 5] 4 is a cross-sectional view perpendicular to the main surfaces of a pair of flange pieces. FIG. [Figure 6] FIG. 2 is a perspective view of the container from the outside. [Figure 7] FIG. 5 is a plan view of a blank sheet for producing the container shown in FIG. [Figure 8] FIG. 2 is a side view of a container produced in Comparative Example 1. [Figure 9] FIG. 2 is a side view of the container produced in Example 1. [Figure 10] FIG. 13 is a diagram showing the results of an experiment on the floating of a container. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated descriptions are omitted. The drawings may be partially simplified or exaggerated for ease of understanding, and the dimensional ratios, angles, etc. are not limited to those shown in the drawings.

[0019] Fig. 1 is a perspective view of a container according to one embodiment. The container 1 shown in Fig. 1 contains contents such as food. The contents are not limited to food. The container 1 shown in Fig. 1 is a paper tray, and is formed by folding a blank sheet 10, as described below. The blank sheet 10 is a mount made of a paper base material 7.

[0020] In the following description, the three mutually perpendicular axial directions will be described as the "X direction," "Y direction," and "Z direction." The X direction is the direction of the short sides of the container 1, and the Y direction is the direction of the long sides of the container 1. The Z direction is the depth direction of the container 1. In the following description, "inside" means the direction facing the inside of the container 1 (storage space S), and "outside" means the opposite direction to "inside."

[0021] [container] As shown in FIG. 1, the container 1 includes a bottom wall 2, a side wall 3, a flange 4, a panel 5, and a panel flange 6. The container 1 is a paper container made of a paper base material 7. The bottom wall 2 has a substantially rectangular planar shape. The side wall 3 stands upright from the outer edge of the bottom wall 2, and together with the bottom wall 2, defines a storage space S for storing contents. The upper part of the storage space S is open, and a substantially rectangular opening M is formed. The contents are put in and taken out through this opening M. The shape of the opening M may be any shape, such as a circle, an ellipse, or a polygon.

[0022] The bottom wall 2 has a pair of bases (multiple bases) 21 and a partition 22. Each of the pair of bases 21 is disposed on a plane perpendicular to the Z direction and has a substantially rectangular shape. The partition 22 is disposed between the pair of bases 21 and protrudes toward the opening M. When viewed from the Z direction, the partition 22 extends in the X direction. The length of the partition 22 in the X direction is substantially the same as the width of the bottom wall 2 in the X direction. Both ends of the partition 22 in the X direction abut against a pair of first side walls 31, which will be described later.

[0023] The partition 22 divides the storage space S into two small spaces S1 and S2. Different types of contents are stored in the small spaces S1 and S2. For example, if the contents stored in the container 1 are food, cooked rice is placed in one of the small spaces S1 and S2, and side dishes are placed in the other of the small spaces S1 and S2. The partition 22 also provides rigidity to the container 1 to prevent the bottom wall portion 2 from bending.

[0024] As shown in FIG. 1, the partition 22 has a first surface 22a standing along a first fold line 51 from one (first base) of the pair of bases 21, a second surface 22b standing along a fourth fold line 54 from the other (second base) of the pair of bases 21, and a third surface 22c connecting the first surface 22a and the second surface 22b. The third surface 22c is connected to the first surface 22a and the second surface 22b via the second fold line 52 and the third fold line 53, respectively. The partition 22 has a substantially trapezoidal outline when viewed from the X direction. In one embodiment, the first surface 22a and the second surface 22b are inclined with respect to the pair of bases 21. The inclination angle of the first surface 22a and the second surface 22b with respect to the base 21 is 90° or less, for example, 60°.

[0025] The height of third surface 22c of partition 22 (height of partition 22) based on the pair of bases 21 may be 75% or less of the height of flange portion 4 (height of container 1) described below based on the pair of bases 21. The height of partition 22 may be 50% or less of the height of container 1. If the height of partition 22 is increased, the restoring force acting on container 1 increases, making it easier for warping to occur in bottom wall portion 2. In response to this, by setting the height of partition 22 to 75% or less of the height of container 1, warping of bottom wall portion 2 can be suppressed.

[0026] The side wall portion 3 has a pair of first side walls 31 facing each other in the X direction, a pair of second side walls 32 facing each other in the Y direction, and a plurality of corner walls 33. The pair of first side walls 31 are erected from the outer edge of the base 21 of the bottom wall portion 2, and the main surfaces thereof are substantially oriented in the X direction. That is, the pair of first side walls 31 define the storage space S from the X direction.

[0027] The pair of first side walls 31 includes a plurality of side wall pieces erected from the outer edge of the bottom wall portion 2. Specifically, each of the pair of first side walls 31 has a pair of side wall pieces 31a, 31b consisting of a first side wall piece 31a and a second side wall piece 31b. The pair of side wall pieces 31a, 31b are disposed adjacent to each other in the Y direction. The first side wall pieces 31a of the pair of first side walls 31 face each other in the X direction, and the second side wall pieces 31b of the pair of first side walls 31 face each other in the X direction.

[0028] The small space S1 is defined by the first side wall pieces 31a of the pair of first side walls 31, one of the pair of second side walls 32, and the first surface 22a of the partition 22. The small space S2 is defined by the second side wall pieces 31b of the pair of first side walls 31, the other of the pair of second side walls 32, and the second surface 22b of the partition 22.

[0029] The pair of second side walls 32 are erected from the outer edge of the base 21 of the bottom wall portion 2, and their main surfaces are substantially oriented in the Y direction. That is, the pair of second side walls 32 define the storage space S from the Y direction. The multiple corner walls 33 are erected from the outer edge of the base 21 of the bottom wall portion 2, and are respectively disposed between the pair of first side walls 31 and the pair of second side walls 32. In the embodiment shown in FIG. 1, the container 1 has four corner walls 33. The four corner walls 33 rise from the four corners of the bottom wall portion 2.

[0030] The flange portion 4 protrudes outward from the upper end of the side wall portion 3. The flange portion 4 is provided, for example, parallel to the base portion 21 of the bottom wall portion 2 and extends in a substantially rectangular shape so as to surround the outer edge of the opening M. The flange portion 4 is used as a handle to be grasped when lifting the container 1.

[0031] The flange portion 4 includes a pair of first flanges 41, a pair of second flanges 42, and a plurality of corner flanges 43. The pair of first flanges 41 includes a plurality of flange pieces. Specifically, each of the pair of first flanges 41 has a pair of flange pieces 41a, 41b consisting of a first flange piece 41a and a second flange piece 41b. The pair of flange pieces 41a, 41b are disposed adjacent to each other in the Y direction. The first flange piece 41a protrudes outward from the upper end of the first side wall piece 31a. The second flange piece 41b protrudes outward from the upper end of the second side wall piece 31b.

[0032] The pair of second flanges 42 protrude outwardly from upper ends of the pair of second side walls 32, respectively. The multiple corner flanges 43 protrude outwardly from upper ends of the multiple corner walls 33, respectively. In the embodiment shown in FIG. 1, the container 1 has four corner flanges 43 arranged at the four corners of the flange portion 4.

[0033] Both ends of the pair of first flanges 41 and both ends of the pair of second flanges 42 are joined in an overlapping state to the multiple corner flanges 43. For example, both ends of the pair of first flanges 41 are bonded to the multiple corner flanges 43 with an adhesive, and both ends of the pair of second flanges 42 are bonded to the multiple corner flanges 43 with an adhesive.

[0034] The panel 5 is connected to the partition 22. Specifically, the panel 5 is connected to the third surface 22c of the partition 22 and stands along the edge of the third surface 22c in the X direction. The panel 5 has a substantially rectangular shape and has a width in the Y direction that is substantially the same as the width of the third surface 22c. The width of the panel 5 in the Y direction may be smaller than the width of the third surface 22c in the Y direction. The panel 5 partially overlaps the pair of side wall pieces 31a, 31b in the thickness direction. FIG. 2 is a side view of the container 1 as viewed from the X direction. As shown in FIG. 2, the panel 5 is disposed outside the pair of side wall pieces 31a, 31b.

[0035] In one embodiment, the pair of side wall pieces 31a, 31b may be joined in a partially overlapping state to the panel 5. For example, as shown in Fig. 2, ends of the pair of side wall pieces 31a, 31b are overlapped on the panel 5 from the inside and adhered to the panel 5 with an adhesive. Note that, as will be described later, when the pair of flange pieces 41a, 41b are joined to the panel flange 6, the pair of side wall pieces 31a, 31b do not have to be joined to the panel 5.

[0036] The panel flange 6 protrudes outward from the upper end of the panel 5. The panel flange 6 is provided, for example, parallel to the base 21 of the bottom wall portion 2 and arranged so as to overlap the pair of flange pieces 41a, 41b in the thickness direction. The pair of flange pieces 41a, 41b are joined in a state where they are overlapped on the panel flange 6. For example, the ends of the pair of flange pieces 41a, 41b are adhered to the upper surface of the panel flange 6 with an adhesive. As a result, the pair of flange pieces 41a, 41b are joined to each other via the panel flange 6.

[0037] [Blank sheet] Next, a blank sheet 10 used to create the container 1 will be described. Fig. 3 is a plan view of the blank sheet 10 according to one embodiment. The container 1 is formed by folding the blank sheet 10 along the fold lines. In Fig. 3, the fold lines are indicated by two-dot chain lines.

[0038] The blank sheet 10 shown in FIG. 3 is a mount having a substantially rectangular shape and made of a paper base material 7. The paper base material 7 is a paper sheet whose main component is general wood pulp. For example, the paper base material 7 may be card paper, Manila cardboard, coated paper, ivory paper, or the like. Note that a coating layer may be formed on the outer surface of the paper base material 7 to improve printability.

[0039] 3, the two directions perpendicular to each other are illustrated as an “x direction” and a “y direction.” As shown in FIG. 3, the blank sheet 10 has a bottom wall sheet portion 11, a side wall sheet portion 12, and a panel sheet portion 13.

[0040] The bottom wall sheet portion 11 has a substantially rectangular shape and constitutes the bottom wall portion 2 when folded into the shape of the container 1. The bottom wall sheet portion 11 has a first fold line 51, a second fold line 52, a third fold line 53, and a fourth fold line 54 that extend parallel to each other in the x direction (first direction) and are arranged in this order in the y direction (second direction) perpendicular to the x direction. The bottom wall sheet portion 11 is valley-folded along the first fold line 51 and the fourth fold line 54, and the bottom wall sheet portion 11 is mountain-folded along the second fold line 52 and the third fold line 53, thereby forming the bottom wall portion 2 having a pair of base portions 21 and a partition 22.

[0041] In the bottom wall sheet portion 11, when the region between the first fold line 51 and the second fold line 52 is defined as the first region R1, the region between the third fold line 53 and the fourth fold line 54 is defined as the second region R2, and the region between the second fold line 52 and the third fold line 53 is defined as the third region R3, the width w1 of the first region R1 in the y direction and the width w2 of the second region R2 in the y direction may be substantially equal. By making the width w1 and the width w2 equal, the partition 22 having a trapezoidal shape when viewed from the X direction is formed.

[0042] The side wall sheet portion 12 constitutes the side wall portion 3 and the flange portion 4 when folded into the shape of the container 1. The side wall sheet portion 12 includes a pair of first side wall sheet portions 14, a pair of second side wall sheet portions 15, and a plurality of corner wall sheet portions 16. The pair of first side wall sheet portions 14 constitute a pair of first side walls 31 and a pair of first flanges 41 when folded into the shape of the container 1. The pair of second side wall sheet portions 15 constitute a pair of second side walls 32 and a pair of second flanges 42 when folded into the shape of the container 1. The plurality of corner wall sheet portions 16 constitute a plurality of corner walls 33 and a plurality of corner flanges 43 when folded into the shape of the container 1.

[0043] Each of the pair of first sidewall sheet portions 14 has a pair of sidewall sheet pieces 14a, 14b consisting of a first sidewall sheet piece 14a and a second sidewall sheet piece 14b. The pair of sidewall sheet pieces 14a, 14b are connected to an edge 25 of the bottom wall sheet portion 11 in the x direction. The pair of sidewall sheet pieces 14a, 14b are valley-folded along a fold line F1 extending along the edge 25, the pair of sidewall sheet pieces 14a, 14b are mountain-folded along a fold line F2 extending along the y direction, and the pair of sidewall sheet pieces 14a, 14b are valley-folded along a pair of fold lines F3 extending in the x direction, thereby forming a pair of sidewall pieces 31a, 31b and a pair of flange pieces 41a, 41b.

[0044] The pair of second sidewall sheet portions 15 are connected to an edge 26 of the bottom wall sheet portion 11 in the y direction. The pair of second sidewall sheet portions 15 are valley-folded along a fold line F4 extending along the edge 26, the pair of second sidewall sheet portions 15 are mountain-folded along a fold line F5 extending in the x direction, and the pair of second sidewall sheet portions 15 are valley-folded along a pair of fold lines F6 extending in the y direction, thereby forming a pair of second side walls 32 and a pair of second flanges 42.

[0045] The corner wall sheet portions 16 are connected to the outer edge of the bottom wall sheet portion 11. The corner walls 33 and the corner flanges 43 are formed by folding the corner wall sheet portions 16 in a valley direction along a fold line F7 that extends obliquely in the x-direction and the y-direction, and by folding the corner wall sheet portions 16 in a mountain direction along a fold line F8 that is parallel to the fold line F7.

[0046] The panel sheet portion 13 has a substantially rectangular shape and constitutes the panel 5 and the panel flange 6 when folded into the shape of the container 1. As shown in FIG. 3, the panel sheet portion 13 is disposed between a pair of side wall sheet pieces 14a, 14b. The panel sheet portion 13 is connected to the third region R3 between the second fold line 52 and the third fold line 53 in the bottom wall sheet portion 11, and extends in the x direction from the third region R3. The width of the panel sheet portion 13 in the y direction is equal to or smaller than the width of the third region R3 in the second direction. Typically, the width of the panel sheet portion 13 in the y direction is the same as the width of the third region R3 in the second direction. When the blank sheet 10 is folded into the shape of the container 1, in order to prevent interference between the pair of side wall sheet pieces 14a, 14b and the panel sheet portion 13, a triangular gap may be formed between each of the pair of side wall sheet pieces 14a, 14b and the panel sheet portion 13.

[0047] The panel 5 and the panel flange 6 are formed by folding the panel sheet portion 13 in a valley along a fold line F9 extending along the edge 25 and by folding the panel sheet portion 13 in a mountain along a fold line F10 extending in the y direction.

[0048] [Container formation method] Next, a method for forming the container 1 using the above-mentioned blank sheet 10 will be described. To form the container 1, first, the bottom wall sheet portion 11 is folded along the first fold line 51, the second fold line 52, the third fold line 53, and the fourth fold line 54 to form the bottom wall portion 2 having a pair of base portions 21 and a partition 22. In addition, the side wall sheet portion 12 is folded along the fold lines F1 to F8 to form the side wall portion 3 and the flange portion 4, and the panel sheet portion 13 is folded along the fold lines F9 and F10 to form the panel 5 and the panel flange 6. At this time, the panel 5 is disposed outside the pair of side wall pieces 31a and 31b of the side wall portion 3.

[0049] As described above, when the side wall sheet portion 12 and the panel sheet portion 13 are folded, the pair of flange pieces 41a, 41b partially overlap the panel flange 6. Then, the overlapping portions of the pair of flange pieces 41a, 41b and the panel flange 6 are bonded with an adhesive. As a result, the pair of flange pieces 41a, 41b are joined via the panel flange 6. At this time, the joint portion of the pair of flange pieces 41a, 41b is supported by the panel 5 connected to the panel flange 6, so that the shape retention of the container 1 is improved.

[0050] Similarly, when the side wall sheet portion 12 is folded, the pair of first flanges 41 and the pair of second flanges 42 partially overlap the multiple corner flanges 43. Then, the overlapping portions of the pair of first flanges 41 and the multiple corner flanges 43, and the overlapping portions of the pair of second flanges 42 and the multiple corner flanges 43 are bonded with an adhesive. As a result, the pair of flange pieces 41a, 41b are joined via the multiple corner flanges 43. In this manner, the container 1 is produced.

[0051] In one embodiment, after the container 1 is produced, a stretchable resin film may be adhered to the inner surface of the container 1 by pressure forming. When the resin film is adhered to the inner surface of the container 1, the shape of the container 1 is maintained by the resin film, so that each of the pair of flange pieces 41a, 41b and the panel flange 6 do not necessarily need to be adhered with an adhesive.

[0052] As described above, in the container 1, the pair of flange pieces 41a, 41b are joined in an overlapping state to the panel flange 6. This allows the joint between the pair of flange pieces 41a, 41b to be supported by the panel 5 connected to the panel flange 6, improving the rigidity of the joint between the pair of flange pieces 41a, 41b. This improves the shape retention of the container 1, and as a result, the corners of the bottom wall portion 2 are prevented from floating.

[0053] [Variations] Next, a container according to another embodiment will be described. Fig. 4 is a diagram showing a schematic view of a container 1A according to another embodiment. In the following, differences from the container 1 shown in Fig. 1 will be mainly described, and overlapping descriptions will be omitted.

[0054] The container 1A is formed by folding a blank sheet 10A, which will be described later. The blank sheet 10A is configured by laminating a paper base material 7 and a resin film 8 (see FIG. 5). Therefore, the inner surface of the container 1A is covered with the resin film 8. The resin film 8 is configured, for example, from a heat-sealable thermo-flexible resin.

[0055] The pair of flange pieces 41a, 41b of the container 1A are partially overlapped on the panel flange 6 from the thickness direction D of the pair of flange pieces 41a, 41b. Fig. 5 is a cross-sectional view perpendicular to the main surface of the pair of flange pieces 41a, 41b. In the embodiment shown in Fig. 5, the pair of flange pieces 41a, 41b are overlapped on the panel flange 6 from above. Typically, the thickness direction D of the pair of flange pieces 41a, 41b coincides with the Z direction.

[0056] 5, the resin film 8 is disposed in a folded state between each of the pair of flange pieces 41a, 41b and the panel flange 6. Each of the pair of flange pieces 41a, 41b and the panel flange 6 are joined to each other in a partially overlapping state in the thickness direction D by fusing the resin film 8 disposed therebetween in a folded state.

[0057] In addition, both ends of the pair of first flanges 41 and both ends of the pair of second flanges 42 are overlapped with the multiple corner flanges 43. Between the pair of first flanges 41 and the multiple corner flanges 43 and between the pair of second flanges 42 and the multiple corner flanges 43, a resin film 8 is arranged in a folded state. The pair of first flanges 41 and the pair of second flanges 42 are joined to the multiple corner flanges 43 in a partially overlapping state from the thickness direction by fusing the resin film 8 arranged between the pair of first flanges 41 and the multiple corner flanges 43 and between the pair of second flanges 42 and the multiple corner flanges 43 in a folded state.

[0058] FIG. 6 is a perspective view of the container 1 from the outside. As shown in FIG. 6, in the container 1A, the panel 5 extends from the third surface 22c of the partition 22 between the pair of side wall pieces 31a, 31b to the outside of the container 1, and is raised along the fold line F9. The fold line F9 is formed between the outer edge of the bottom wall portion 2 (the outer edge of the third surface 22c of the partition 22) and the panel flange 6. The panel flange 6 protrudes outward from the upper end of the panel 5 and is overlapped with the pair of flange pieces 41a, 41b. As described above, each of the pair of flange pieces 41a, 41b and the panel flange 6 are joined to each other in a state where they are partially overlapped from the thickness direction D.

[0059] 7 is a plan view of a blank sheet 10A according to another embodiment. The blank sheet 10A is used to produce a container 1A. The blank sheet 10A is configured by laminating a paper base material 7 and a resin film 8.

[0060] 7, in the blank sheet 10A, a window portion W1 is formed by cutting out the paper base material 7 between each of the pair of side wall sheet pieces 14a, 14b and the panel sheet portion 13. The window portion W1 is an area that does not have the paper base material 7 and has only the resin film 8. That is, the resin film 8 is disposed so as to straddle between each of the pair of side wall sheet pieces 14a, 14b and the panel sheet portion 13. When the blank sheet 10A is folded to form the container 1A, the resin film 8 of the window portion W1 is disposed in a folded state between the pair of flange pieces 41a, 41b.

[0061] Similarly, window portions W2 having no paper base material 7 but only a resin film 8 are formed between a pair of first side wall sheet portions 14 and a plurality of corner wall sheet portions 16, and between a pair of second side wall sheet portions 15 and a plurality of corner wall sheet portions 16.

[0062] When forming the container 1A using the blank sheet 10A, first, the bottom wall sheet portion 11 is folded along the first fold line 51, the second fold line 52, the third fold line 53, and the fourth fold line 54 to form the bottom wall portion 2 having a pair of base portions 21 and a partition 22. In addition, the side wall sheet portion 12 is folded along the fold lines F1, F2, F4, F5, F7, and F8 to form the side wall portion 3 and the flange portion 4, and the panel sheet portion 13 is folded along the fold lines F9 and F10 to form the panel 5 and the panel flange 6. At this time, the panel 5 is disposed outside the pair of side wall pieces 31a and 31b of the side wall portion 3. In addition, as shown in FIG. 7, the fold line F9 of the panel sheet portion 13 is disposed outside the edge 25 of the bottom wall sheet portion 11 in the x direction (the fold line F10 side). Therefore, the panel 5 is bent at a position shifted toward the panel flange 6 from the outer edge of the bottom wall portion 2 (the outer edge of the third surface 22c of the partition 22) (see FIG. 6).

[0063] As described above, when the bottom wall sheet portion 11 is folded along the first fold line 51, the second fold line 52, the third fold line 53, and the fourth fold line 54, the pair of side wall sheet pieces 14a, 14b move in directions approaching each other, and the pair of flange pieces 41a, 41b partially overlap the panel flange 6. At this time, the resin film 8 of the window portion W1 is disposed in a folded state between the panel flange 6 and each of the pair of side wall sheet pieces 14a, 14b.

[0064] Furthermore, when the side wall sheet portion 12 is folded, the pair of first flanges 41 and the pair of second flanges 42 partially overlap the multiple corner flanges 43. At this time, the resin film 8 is arranged in a folded state between the pair of first flanges 41 and the multiple corner flanges 43, and between the pair of second flanges 42 and the multiple corner flanges 43.

[0065] Next, the flange portion 4 is heated from above, and the resin film 8 folded between the panel flange 6 and each of the pair of side wall sheet pieces 14a, 14b is heat-sealed. As a result, the pair of flange pieces 41a, 41b are joined to the panel flange 6 in a state where they are overlapped. At this time, the resin film 8 folded between the pair of first flanges 41 and the multiple corner flanges 43, and between the pair of second flanges 42 and the multiple corner flanges 43 are also heat-sealed. As a result, the pair of first flanges 41 and the multiple corner flanges 43, and the pair of second flanges 42 and the multiple corner flanges 43 are joined to each other in a state where they are overlapped. In this manner, the container 1A is produced.

[0066] In the container 1A described above, the pair of flange pieces 41a, 41b are joined in an overlapping state to the panel flange 6. This allows the panel 5 connected to the panel flange 6 to support the joint between the pair of flange pieces 41a, 41b, improving the rigidity of the joint between the pair of flange pieces 41a, 41b. This improves the shape retention of the container 1A, and as a result, the corners of the bottom wall portion 2 are prevented from floating.

[0067] Although the containers 1, 1A according to various embodiments have been described above, the present invention is not limited to the above-described embodiments and various modifications can be made without departing from the spirit and scope of the invention.

[0068] In the above-described embodiment, the ends of the pair of flange pieces 41a, 41b of the container 1 are adhered to the panel flange 6 with an adhesive, but the means for joining the pair of flange pieces 41a, 41b to the panel flange 6 is not limited to adhesive. For example, the pair of flange pieces 41a, 41b may be joined to the panel flange 6 by fusing a thermoplastic resin arranged between each of the pair of flange pieces 41a, 41b and the panel flange 6.

[0069] In addition, in the above-described embodiment, the panel 5 is positioned outside the pair of side wall pieces 31a, 31b, and the panel flange 6 is joined from the underside of the pair of flange pieces 41a, 41b, but in one embodiment, the panel 5 may be positioned inside the pair of side wall pieces 31a, 31b, and the pair of flange pieces 41a, 41b may be joined to the underside of the panel flange 6.

[0070] The various embodiments described above can be combined to the extent that no contradiction occurs.

[0071] Next, the effects of the above-mentioned containers 1, 1A will be described based on examples and comparative examples, but the present invention is not limited to the following examples.

[0072] First, in Example 1, a blank sheet made of paper was folded to produce a container 1 shown in FIG. 1. The width of the container 1 in the short side direction was 114.4 mm, and the length of the container 1 in the long side direction was 154.4 mm. The height h1 of the container 1 (the height of the flange portion 4 based on the base portion 21) was 25 mm, and the height h2 of the partition 22 of the container 1 (the height of the third surface 22c based on the base portion 21) was 8.67 mm. The inclination angle of the first surface 22a and the second surface 22b based on the base portion 21 was 60°. The width of the panel 5 in the long side direction of the container 1 was 10 mm. Then, the produced container 1 was placed on a horizontal placement surface T, and visually evaluated whether or not there was any lift in the corners of the bottom wall portion 2.

[0073] On the other hand, in Comparative Example 1, a container 100 having the same dimensions as container 1 was made by folding a paper blank sheet. Container 100 differs from container 1 in that it does not have panel 5 and panel flange 6. Then, the made container 100 was placed on a horizontal placement surface T, and the presence or absence of lifting at the corners of the bottom wall portion 2 was visually evaluated.

[0074] Fig. 8 shows the container 100 produced in Comparative Example 1. As shown in Fig. 8, it was confirmed that the corners of the bottom wall 2 of the container 100 rose up relative to the placement surface T. Since the container 100 does not include the panel 5 and the panel flange 6, the joining strength of the pair of flange pieces 41a, 41b is weak. Therefore, it is considered that the restoring force of the container 100 caused the container 100 to bend from the joining portion of the pair of flange pieces 41a, 41b, causing the bottom wall 2 to warp, and thus causing the corners of the bottom wall 2 to rise up.

[0075] On the other hand, Fig. 9 shows the container 1 produced in Example 1. As shown in Fig. 9, it was confirmed that the corners of the bottom wall portion 2 of the container 1 do not rise above the placement surface T. In the container 1, the pair of flange pieces 41a, 41b are joined to the panel flange 6, and the joint portion of the pair of flange pieces 41a, 41b is supported by the panel 5 connected to the panel flange 6, so that the joining strength of the pair of flange pieces 41a, 41b is high. As a result, it is considered that the warping of the bottom wall portion 2 is suppressed.

[0076] Next, the relationship between the height of the partition 22 and the floating of the container 1 was evaluated. In Examples 2 to 5 and Comparative Example 2, a plurality of containers having different heights h2 of the partition 22 were produced. In Examples 2 to 5, the heights h2 of the partition 22 were set to 25 mm, 20 mm, 15 mm, and 10 mm, respectively. In Comparative Example 2, the height h2 of the partition 22 was set to 30 mm. In Examples 2 to 5 and Comparative Example 2, the height h1 of the container 1 was 35 mm. The ratio of the height h2 of the partition to the height h1 of the container in Examples 2 to 5 and Comparative Example 2 is as shown in FIG. 10. Then, the containers produced in Examples 2 to 5 and Comparative Example 2 were placed on a horizontal placement surface T, and visually evaluated whether or not there was floating in the corners of the bottom wall portion 2.

[0077] FIG. 10 shows the evaluation results regarding the presence or absence of floating. A circle in FIG. 10 indicates that there is no floating at the corner of the bottom wall portion 2, and a cross in FIG. 10 indicates that floating is confirmed at the corner of the bottom wall portion 2. As shown in FIG. 10, no floating of the container was confirmed in the containers produced in Examples 2 to 5, but floating was confirmed in the container produced in Comparative Example 2. From this result, it was confirmed that floating of the container can be suppressed by setting the partition height h2 to 75% or less of the container height h1.

[0078] The present disclosure includes the following: [1] A container formed by folding a blank sheet having a paper base material, a bottom wall including a plurality of bases and dividers; a side wall portion including a plurality of side wall pieces extending from an outer edge of the bottom wall portion, the side wall portion defining an accommodation space together with the bottom wall portion; a flange portion having a plurality of flange pieces extending outward from upper ends of the plurality of side wall pieces; a panel connected to the partition; A panel flange extending outward from an upper end of the panel; Equipped with the partition has a first surface erected from a first base portion of the plurality of base portions, a second surface erected from a second base portion of the plurality of base portions, and a third surface connecting the first surface and the second surface, and divides the storage space into a plurality of small spaces; the panel extends from the third surface of the divider; A container, wherein a pair of adjacent flange pieces among the plurality of flange pieces are joined to the panel flange in an overlapping state. [2] The blank sheet has a resin film laminated on the paper base material, The container described in [1], wherein the pair of flange pieces are joined to the panel flange by fusing the resin film folded between each of the pair of flange pieces and the panel flange. [3] A container as described in [1] or [2], wherein the pair of flange pieces are adhered to the panel flanges by an adhesive. [4] The blank sheet includes a bottom wall sheet portion that constitutes the bottom wall portion when folded into the shape of the container, a side wall sheet portion that constitutes the side wall portion and the flange portion when folded into the shape of the container, and a panel sheet portion that constitutes the panel and panel flange when folded into the shape of the container, The bottom wall sheet portion has a first fold line, a second fold line, a third fold line, and a fourth fold line that extend parallel to each other in a first direction and are arranged in this order in a second direction perpendicular to the first direction to form the partition; The container described in [2], wherein the panel sheet portion is connected to the area between the second fold line and the third fold line of the bottom wall sheet portion and extends from the area in the first direction. [5] A container as described in [4], wherein the width of the panel sheet portion in the second direction is less than or equal to the width of the region in the second direction. [6] A container as described in [4] or [5], wherein the panel sheet portion has a rectangular shape. [7] A container described in any one of [1] to [6], wherein the panel flange is joined to the pair of flange pieces in a superimposed state from the underside sides of the pair of flange pieces. [8] A container described in any one of [1] to [7], wherein the height of the third surface based on the multiple bases is 75% or less of the height of the flange portion based on the multiple bases. [9] A container described in any one of [2] to [8], wherein the panel is folded along a fold line formed between the outer edge of the bottom wall portion and the panel flange. [Explanation of symbols]

[0079] 1,1A...container, 2...bottom wall portion, 3...side wall portion, 4...flange portion, 5...panel, 6...panel flange, 7...paper base material, 8...resin film, 10,10A...blank sheet, 11...bottom wall sheet portion, 12...side wall sheet portion, 13...panel sheet portion, 21...base, 22...partition, 22a...first surface, 22b...second surface, 22c...third surface, 31a,31b...pair of side wall pieces, 41a,41b...pair of flange pieces, 51...first fold line, 52...second fold line, 53...third fold line, 54...fourth fold line, F9...fold line, S...storage space, S1,S2...small space.

Claims

1. A container formed by folding a blank sheet having a paper substrate, a bottom wall including a plurality of bases and dividers; a side wall portion including a plurality of side wall pieces extending from an outer edge of the bottom wall portion, the side wall portion defining an accommodation space together with the bottom wall portion; a flange portion having a plurality of flange pieces extending outward from upper ends of the plurality of side wall pieces; a panel connected to the partition; A panel flange extending outward from an upper end of the panel; Equipped with the partition has a first surface standing from a first base portion of the plurality of base portions, a second surface standing from a second base portion of the plurality of base portions, and a third surface connecting the first surface and the second surface, and divides the storage space into a plurality of small spaces; the panel extends from the third surface of the divider; A container, wherein a pair of adjacent flange pieces among the plurality of flange pieces are joined to the panel flange in an overlapping state.

2. The blank sheet has a resin film laminated on the paper base material, The container according to claim 1 , wherein the pair of flange pieces are joined to the panel flange by fusing the resin film folded between each of the pair of flange pieces and the panel flange.

3. 2. The container of claim 1, wherein the pair of flange pieces are adhered to the panel flanges by an adhesive.

4. the blank sheet includes a bottom wall sheet portion that constitutes the bottom wall portion when folded into the shape of the container, a side wall sheet portion that constitutes the side wall portion and the flange portion when folded into the shape of the container, and a panel sheet portion that constitutes the panel and panel flange when folded into the shape of the container, The bottom wall sheet portion has a first fold line, a second fold line, a third fold line, and a fourth fold line that extend parallel to each other in a first direction and are arranged in this order in a second direction perpendicular to the first direction to form the partition; The container according to claim 2 , wherein the panel sheet portion is connected to a region between the second fold line and the third fold line of the bottom wall sheet portion and extends from the region in the first direction.

5. The container according to claim 4 , wherein a width of the panel sheet portion in the second direction is equal to or smaller than a width of the region in the second direction.

6. The container according to claim 4 , wherein the panel sheet portion has a rectangular shape.

7. The container according to claim 1 , wherein the panel flange is joined to the pair of flange pieces in a state where the panel flange is overlapped from the lower surface sides of the pair of flange pieces.

8. The container according to claim 1 , wherein a height of the third surface relative to the base portions is 75% or less of a height of the flange portion relative to the base portions.

9. 3. The container of claim 2, wherein the panel is folded along a fold line formed between an outer edge of the bottom wall and the panel flange.

Images