paper container

Abstract

To provide a paper container that can prevent paper containers from becoming difficult to separate when stacked. [Solution] The paper container 100 according to the present invention is a paper container comprising a tray-shaped paper base material 110 and a resin film 120 attached to the inner surface of the paper base material 110, wherein the paper base material 110 includes a bottom portion 10, a plurality of side wall portions 20 provided along the periphery of the bottom portion 10, a flange portion 60 provided along the upper end of the plurality of side wall portions 20, and flap portions 50 provided on both sides of the edges of a pair of the plurality of side wall portions 20, wherein the pair of side wall portions 20 are connected to the bottom portion 10 via opposing fold lines 30, and the flap portions 50 overlap with the pair of side wall portions 20 and adjacent side wall portions to constitute the inner surface of the paper base material 110, and the side wall portions 20 other than the pair of side wall portions 20 are not provided with flap portions 50.

Description

Technical Field

[0001] The present invention relates to a paper container.

Background Art

[0002] Conventionally, there has been known a paper container formed by shaping a paper base material into a tray shape and attaching a resin film to the shaped paper base material. Such a paper container is used, for example, for storing foods and the like.

[0003] For example, Patent Document 1 describes an assembled paper container having a bottom surface, a plurality of side surfaces rising from the bottom surface, and a flange portion connected to the plurality of side surfaces and having a flush upper surface after assembly. In Patent Document 1, a rib portion extending from the side surface toward the edge of the flange portion is provided. By the rib portion, it is possible to suppress the containers from being easily detached when the assembled paper containers are stacked.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] One of the objects according to some aspects of the present invention is to provide a paper container capable of suppressing the paper containers from being easily detached when stacked.

Means for Solving the Problems

[0006] One aspect of the paper container according to the present invention is a paper container including a tray-shaped paper base material and a resin film attached to the inner surface of the paper base material, wherein the paper base material has a bottom portion, a plurality of side wall portions provided along the periphery of the bottom portion, A flange portion provided along the upper end of the plurality of side wall portions, A flap portion is provided on both edges of a pair of side wall portions among the plurality of side wall portions, Includes, The pair of side walls are connected to the bottom via opposing folded lines, The flap portion overlaps with the pair of side wall portions and adjacent side wall portions, forming the inner surface of the paper substrate. Of the aforementioned plurality of side wall portions, the side wall portions other than the pair of side wall portions are not provided with the flap portion.

[0007] In one embodiment of the paper container according to the present invention, The aforementioned paper substrate is The plurality of side wall portions include a first side wall portion, a second side wall portion, a third side wall portion, and a fourth side wall portion, The aforementioned flap portion comprises a first flap portion, a second flap portion, a third flap portion, and a fourth flap portion, Includes, The first side wall portion is connected to the bottom portion via the first folded line portion, The second side wall portion is connected to the bottom portion via a second fold line portion opposite to the first fold line portion. The third side wall is connected to the bottom via a third folded line that connects the first folded line and the second folded line. The fourth side wall portion is connected to the bottom portion via a fourth fold line portion opposite to the third fold line portion. The first flap portion is provided on the first edge of the third side wall portion and overlaps with the first side wall portion. The second flap portion is provided on the second edge of the third side wall portion opposite to the first edge portion, and overlaps with the second side wall portion. The third flap portion is provided on the third edge of the fourth side wall portion and overlaps with the first side wall portion. The fourth flap portion may be provided on the fourth edge of the fourth side wall portion opposite to the third edge portion, and may overlap with the second side wall portion.

[0008] In one embodiment of the paper container according to the present invention, The first flap portion, the second flap portion, the third flap portion, and the fourth flap portion may be separated from each other.

[0009] In one aspect of the paper container according to the present invention, The length of the first fold line portion is smaller than the lengths of the third fold line portion and the fourth fold line portion, The length of the second fold line portion may be smaller than the lengths of the third fold line portion and the fourth fold line portion.

[0010] In one aspect of the paper container according to the present invention, The first flap portion and the second flap portion contact the lower end of the third side wall portion, The third flap portion and the fourth flap portion may contact the lower end of the fourth side wall portion.

[0011] In one aspect of the paper container according to the present invention, The thickness of the resin film may be smaller than the thickness of the flap portion.

[0012] In one aspect of the paper container according to the present invention, The angle of the side wall portion with respect to the bottom portion may be an obtuse angle.

[0013] In one aspect of the paper container according to the present invention, The first fold line portion has a first portion having a first through portion and a first non-through portion, and a second portion having a second through portion longer than the first through portion, and has The end of the first fold line portion may be constituted by the first non-through portion.

Advantages of the Invention

[0014] According to the paper container of the present invention, it includes flap portions provided at the edges on both sides of a pair of side wall portions among the plurality of side wall portions. The flap portions overlap with the side wall portions adjacent to the pair of side wall portions and constitute the inner surface of the paper base material. Among the plurality of side wall portions, the flap portions are not provided on the side wall portions other than the pair of side wall portions. Therefore, when the paper containers are stacked, it is possible to suppress the paper containers from being easily detached.

Brief Description of the Drawings

[0015] [Figure 1] A plan-side perspective view schematically showing the paper container according to the present embodiment. [Figure 2] A bottom-side perspective view schematically showing the paper container according to the present embodiment. [Figure 3] A plan view schematically showing the paper container according to the present embodiment. [Figure 4] A side view schematically showing the paper container according to the present embodiment. [Figure 5] A cross-sectional view schematically showing the paper container according to the present embodiment. [Figure 6] A view schematically showing a developed view of the paper base material of the paper container according to the present embodiment. [Figure 7] A cross-sectional view schematically showing the manufacturing process of the paper container according to the present embodiment. [Figure 8] A cross-sectional view schematically showing the manufacturing process of the paper container according to the present embodiment. [Figure 9] A cross-sectional view schematically showing the manufacturing process of the paper container according to the present embodiment. [Figure 10] A cross-sectional view schematically showing the manufacturing process of the paper container according to the present embodiment. [Figure 11] A cross-sectional view schematically showing the manufacturing process of the paper container according to the present embodiment.

Modes for Carrying Out the Invention

[0016] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the embodiments described below do not unduly limit the content of the present invention described in the claims. Also, not all of the configurations described below are essential constituent elements of the present invention.

[0017] 1. Paper container 1.1. Structure The paper container according to this embodiment will be described with reference to the drawings. Figure 1 is a schematic plan view perspective of the paper container 100 according to this embodiment. Figure 2 is a schematic bottom view perspective of the paper container 100 according to this embodiment. Figure 3 is a schematic plan view of the paper container 100 according to this embodiment. Figure 4 is a schematic side view of the paper container 100 according to this embodiment. Figure 5 is a schematic cross-sectional view of the paper container 100 according to Figure 1, taken along line VV. Figure 6 is a schematic diagram showing the unfolded view of the paper base material 110 of the paper container 100 according to this embodiment.

[0018] As shown in Figure 5, the paper container 100 includes a paper base material 110 and a resin film 120. For convenience, the resin film 120 is not shown in Figures 1 to 4.

[0019] The paper substrate 110 has a tray-like shape. The thickness of the paper substrate 110 is, for example, 0.2 mm or more and 2.0 mm or less, preferably 0.5 mm or more and 1.5 mm or less. The material of the paper substrate 110 is paper. The paper substrate 110 is composed of pulp. The material of the paper substrate 110 may be paper to which additives have been added.

[0020] As shown in Figures 1 to 6, the paper substrate 110 includes, for example, a bottom portion 10, a side wall portion 20, a fold line portion 30, a flap portion 50, a flange portion 60, and a fold line portion 70.

[0021] The bottom portion 10 forms the base of the tray-shaped paper substrate 110. In a plan view, the shape of the bottom portion 10 is, for example, a rectangle. In the illustrated example, the shape of the bottom portion 10 in a plan view is a rectangle. Although not shown in the illustration, the shape of the bottom portion 10 in a plan view may also be a square.

[0022] Multiple side wall portions 20 are provided. These multiple side wall portions 20 are provided along the periphery of the bottom portion 10. An opening 22 is formed by the multiple side wall portions 20. The opening 22 is located on the opposite side of the bottom portion 10. As shown in Figure 5, the angle θ of the side wall portion 20 with respect to the bottom portion 10 is obtuse, as shown in Figure 5. The angle θ is, for example, greater than 90° and less than or equal to 135°. In the examples shown in Figures 3 and 6, four side wall portions 20 are provided. The side wall portions 20a and 20b of the wall portion 20 face each other. The side wall portions 20a and 20b have the same shape as each other. The side wall portions 20c and 20d of the multiple side wall portions 20 face each other. The side wall portions 20c and 20d have the same shape as each other. The side wall portions 20 are connected to the bottom portion 10 via the folded line portion 30.

[0023] The fold line portion 30 is provided between the bottom portion 10 and the side wall portion 20. The fold line portion 30 is straight. In the paper substrate 110 before molding shown in Figure 6, the side wall portion 20 is bent relative to the bottom portion 10 by valley folding the paper substrate 110 along the fold line portion 30. Multiple fold line portions 30 are provided, corresponding to multiple side wall portions 20. In the illustrated example, four fold line portions 30 are provided.

[0024] One of the multiple folded line sections 30, folded line section 30a is provided between the bottom section 10 and the side wall section 20a. The side wall section 20a is connected to the bottom section 10 via folded line section 30a. One of the multiple folded line sections 30, folded line section 30b is provided between the bottom section 10 and the side wall section 20b. Folded line section 30b faces folded line section 30a. The side wall section 20b is connected to the bottom section 10 via folded line section 30b. One of the multiple folded line sections 30, folded line section 30c is provided between the bottom section 10 and the side wall section 20c. Folded line section 30c connects folded line section 30a and folded line section 30b. The side wall section 20c is connected to the bottom section 10 via folded line section 30c. One of the multiple folded line sections 30, folded line section 30d, is provided between the bottom section 10 and the side wall section 20d. The folded line portion 30d faces the folded line portion 30c and connects the folded line portions 30a and 30b. The side wall portion 20d is connected to the bottom portion 10 via the folded line portion 30d. The length of the folded line portion 30a is smaller than the lengths of the folded line portions 30c and 30d. The length of the folded line portion 30b is smaller than the lengths of the folded line portions 30c and 30d. Although not shown in the figures, the length of the folded line portion 30a may be the same as the lengths of the folded line portions 30c and 30d, and the length of the folded line portion 30b may be the same as the lengths of the folded line portions 30c and 30d.

[0025] As shown in Figure 6, the folded portion 30 has, for example, a first portion 33 having a through portion 31 and a non-through portion 32, and a second portion 36 having a through portion 34 and a non-through portion 35. The folded portion 30 is composed of, for example, the first portion 33 and the second portion 36.

[0026] In the first portion 33 of the fold line section 30, through-sections 31 and non-through-sections 32 are provided alternately. In the illustrated example, in the first portion 33, there are two through-sections 31 and three non-through-sections 32. In the first portion 33, the multiple through-sections 31 are arranged at predetermined intervals. The first portion 33 constitutes a perforation. The through-sections 31 penetrate the paper substrate 110. The through-sections 31 are provided in a straight line. The length of the through-sections 31 is, for example, 1.0 mm or more and 5.0 mm or less, preferably 2.0 mm or more and 4.0 mm or less.

[0027] In the second portion 36 of the folded line portion 30, for example, multiple through portions 34 are provided. In the illustrated example, in the second portion 36, two through portions 34 are provided and one non-through portion 35 is provided. In the second portion 36, the non-through portion 35 is provided between the two through portions 34. The through portions 34 penetrate the paper substrate 110. The through portions 34 are provided in a straight line. The length of the through portion 34 is greater than the length of the through portion 31. The length of the through portion 34 is greater than the length of the non-through portion 35. The length of the through portion 34 is, for example, 10 mm or more and 50 mm or less, preferably 20 mm or more and 40 mm or less.

[0028] The ratio of the total length of the portion where the through portion 31 is formed and the portion where the through portion 34 is formed to the length of the folded portion 30 is, for example, 60% to 90%, and preferably 75% to 85%. Specifically, this ratio is the ratio of the total length of the multiple through portions 31 and the multiple through portions 34 to the length of one folded portion 30.

[0029] In the folded section 30, the first section 33 and the second section 36 are arranged alternately. The ends of the folded section 30 are composed of non-penetrating sections 32. Specifically, both ends of the folded section 30 are composed of non-penetrating sections 32. The corners of the bottom section 10 are composed of non-penetrating sections 32 of the folded sections 30 that are connected to each other.

[0030] The flap portion 50 is provided on the side wall portion 20c via the fold line portion 52. Furthermore, the flap portion 50 is provided on the side wall portion 20d via the fold line portion 52. Two flap portions 50 are provided on each of the side wall portions 20c and 20d. In the paper substrate 110 before molding shown in Figure 6, the flap portion 50 is bent relative to the side wall portions 20c and 20d by valley folding the paper substrate 110 along the fold line portion 52.

[0031] As shown in Figures 1 and 3, the flap portion 50 overlaps with the side walls 20a and 20b when the paper substrate 110 is molded into a tray shape. This increases the strength of the tray-shaped paper substrate 110. The flap portion 50 constitutes the inner surface of the tray-shaped paper substrate 110.

[0032] For example, an opening 54 is formed in the flap portion 50. The opening 54 penetrates the flap portion 50. The opening 54 increases the contact area between the side walls 20a, 20b and the resin film 120. This increases the strength of the tray-shaped paper substrate 110.

[0033] The flap portion 50 is provided on both sides of the edges of a pair of side wall portions 20 among the multiple side wall portions 20. The flap portion 50 overlaps with the pair of side wall portions 20 and the adjacent side wall portion 20 to form the inner surface of the paper substrate 110. Of the multiple side wall portions 20, the side wall portions 20 other than the pair of side wall portions 20 are not provided with the flap portion 50. The pair of side wall portions 20 are connected to the bottom portion 10 via opposing fold lines 30.

[0034] Specifically, as shown in Figures 3 and 6, the paper substrate 110 includes a first flap portion 50a, a second flap portion 50b, a third flap portion 50c, and a fourth flap portion 50d as the flap portion 50.

[0035] The first flap portion 50a is provided on the first edge portion 90a of the side wall portion 20c. The first edge portion 90a connects the upper end and the lower end of the side wall portion 20c. The first flap portion 50a overlaps with the side wall portion 20a.

[0036] The second flap portion 50b is provided on the second edge portion 90b of the side wall portion 20c. The second edge portion 90b is the edge opposite to the first edge portion 90a and connects the upper end and lower end of the side wall portion 20c. The second flap portion 50b overlaps with the side wall portion 20b. The flap portions 50a and 50b are in contact with the lower end of the side wall portion 20c. The flap portions 50a and 50b are in contact with the folded line portion 30c. Although not shown in the illustration, the flap portions 50a and 50b do not have to be in contact with the lower end of the side wall portion 20c and the folded line portion 30c. In the illustrated example, the flap portions 50a and 50b are not in contact with the upper end of the side wall portion 20c.

[0037] The third flap portion 50c is provided on the third edge portion 90c of the side wall portion 20d. The third edge portion 90c connects the upper end and the lower end of the side wall portion 20d. The third flap portion 50c overlaps with the side wall portion 20b.

[0038] The fourth flap portion 50d is provided on the fourth edge portion 90d of the side wall portion 20d. The fourth edge portion 90d is the edge opposite to the third edge portion 90c and connects the upper end and lower end of the side wall portion 20d. The fourth flap portion 50d overlaps with the side wall portion 20b. The flap portions 50c and 50d are in contact with the lower end of the side wall portion 20d. The flap portions 50c and 50d are in contact with the folded line portion 30d. Although not shown in the illustration, the flap portions 50c and 50d do not have to be in contact with the lower end of the side wall portion 20d and the folded line portion 30d. In the illustrated example, the flap portions 50c and 50d are not in contact with the upper end of the side wall portion 20d. The flap portions 50a, 50b, 50c, and 50d are spaced apart from each other. The flap portions 50a, 50b, 50c, and 50d have the same shape as each other.

[0039] The flange portion 60 is provided along the upper ends of the multiple side wall portions 20. In other words, the flange portion 60 is provided along the opening 22 formed by the multiple side wall portions 20. The flange portion 60 surrounds the opening 22. The upper surface of the flange portion 60 is parallel to, for example, the upper surface of the bottom portion 10. In the illustrated example, the flange portion 60 is connected to the side wall portions 20a, 20b, 20c, and 20d via the folded line portion 70.

[0040] The width W of the flange portion 60 is, for example, 5.0 mm or more and 10.0 mm or less, preferably 7.5 mm or more and 9.5 mm or less. The width W of the flange portion 60 is the shortest distance between the upper end of the side wall portion 20a and the outer circumference of the flange portion 60.

[0041] The fold line portion 70 is straight. In the paper substrate 110 before molding shown in Figure 6, the flange portion 60 is bent relative to the side wall portions 20a, 20b, 20c, and 20d by mountain folding the paper substrate 110 along the fold line portion 70. In the illustrated example, four fold line portions 70 are provided. Of the multiple fold line portions 70, fold line portion 70a is provided between the side wall portion 20a and the flange portion 60. The flange portion 60 is connected to the side wall portion 20a via the fold line portion 70a.

[0042] As shown in Figure 6, the folded portion 70 has, for example, a through portion 71 and a non-through portion 72. The folded portion 70 is composed of, for example, a through portion 71 and a non-through portion 72. The through portions 71 and the non-through portions 72 are provided alternately. Multiple through portions 71 are arranged at predetermined intervals. The through portions 71 penetrate the paper substrate 110. The through portions 71 are provided in a straight line. In the non-through portions 72, the paper substrate 110 is half-cut. The thickness of the non-through portion 72 is less than half the thickness of the flange portion 60.

[0043] As shown in Figure 5, the resin film 120 is attached to the inner surface of the tray-shaped paper substrate 110. Specifically, the resin film 120 is attached to the bottom 10, the side wall 20, the flap 50, and the flange 60. The adhesive force of the resin film 120 to the paper substrate 110 allows the paper substrate 110 to maintain its tray shape. The thickness of the resin film 120 is less than the thickness of the flap 50. In a plan view, the resin film 120 has a non-overlapping portion 122 that does not overlap with the paper substrate 110. The non-overlapping portion 122 protrudes from the flange 60. When disposing of a used paper container 100, the user can pinch the non-overlapping portion 122 and peel the resin film 120 from the paper substrate 110. This allows the paper substrate 110 and the resin film 120 to be disposed of separately. Note that the non-overlapping portion 122 is not required. In other words, in a plan view, the resin film 120 may be provided so as not to protrude from the paper substrate 110.

[0044] The material of the resin film 120 is a thermoplastic resin. Examples of thermoplastic resins include polypropylene, polyethylene, polyvinyl chloride, polystyrene, acrylic resin, polyester resin, polyethylene terephthalate, polyphenylene ether, polybutylene terephthalate, nylon, polyamide, polycarbonate, polyacetal, polyphenylene sulfide, and polyether ether ketone. These resins may be used individually or mixed as appropriate. The color of the resin film 120 may be colorless and transparent. The resin film 120 may be made by laminating multiple resin films or by resin It may also be a co-extruded product.

[0045] 1.2. Manufacturing method Next, the manufacturing method of the paper container 100 according to this embodiment will be described with reference to the drawings. Figures 7 to 11 are schematic cross-sectional views showing the manufacturing process of the paper container 100 according to this embodiment.

[0046] As shown in Figure 6, the base paper is punched out to form fold lines 30, 52, and 70, thereby creating a paper substrate 110.

[0047] As shown in Figure 7, the paper substrate 110 is placed in the mold 130. Specifically, the bottom portion 10 and the side wall portion 20 are placed in the recess 132 of the mold 130, and the flange portion 60 is placed on the upper surface of the mold 130. This allows the paper substrate 110 to be molded into a tray shape.

[0048] As shown in Figure 8, the resin film 120 is placed on top of the paper substrate 110, and the resin film 120 is heated to a stretchable softness. The heating method is not particularly limited.

[0049] As shown in Figure 9, the heated resin film 120 is pressed against the flange portion 60 with the sealing bar 134. Alternatively, the resin film 120 may be pressed against the flange portion 60 while being sucked.

[0050] As shown in Figure 10, the resin film 120 is sucked in through a suction hole 133 formed on the bottom surface of the recess 132. The resin film 120 is sucked in through the through-holes 31 and 34 of the folded portion 30. This allows the resin film 120 to be welded to the inner surface of the tray-shaped paper substrate 110. In a plan view, the suction hole 133 overlaps, for example, with the folded portion 30.

[0051] As shown in Figure 11, the sealing bar 134 is pulled upward to peel the paper container 100 from the sealing bar 134. The resin film 120 is then cut into a predetermined shape.

[0052] Through the above process, paper container 100 can be manufactured.

[0053] 1.3. Effects The paper container 100 includes a tray-shaped paper base material 110 and a resin film 120 attached to the inner surface of the paper base material 110. The paper base material 110 includes a bottom portion 10, a plurality of side wall portions 20 provided along the periphery of the bottom portion 10, a flange portion 60 provided along the upper ends of the plurality of side wall portions 20, and flap portions 50 provided on both sides of the edges of one pair of the plurality of side wall portions 20. The pair of side wall portions 20 are connected to the bottom portion 10 via opposing fold lines 30, and the flap portions 50 overlap with the pair of side wall portions 20 and adjacent side wall portions 20 to form the inner surface of the paper base material 110, and the side wall portions 20 other than the pair of side wall portions 20 are not provided with flap portions 50.

[0054] Specifically, in the paper container 100, the paper base material 110 includes a plurality of side wall portions 20, namely side wall portion 20a (first side wall portion), side wall portion 20b (second side wall portion), side wall portion 20c (third side wall portion), and side wall portion 20d (fourth side wall portion), and a flap portion 50, namely a first flap portion 50a, a second flap portion 50b, a third flap portion 50c, and a fourth flap portion 50d. The side wall portion 20a is connected to the bottom portion 10 via the folded line portion 30a (first folded line portion), the side wall portion 20b is connected to the bottom portion 10 via the folded line portion 30b (second folded line portion) opposite to the folded line portion 30a, the side wall portion 20c is connected to the bottom portion 10 via the folded line portion 30c (third folded line portion) connecting the folded line portion 30a and the folded line portion 30b, and the side wall portion 20d is connected to the bottom portion 10 via the folded line portion 30d (fourth folded line portion) opposite to the folded line portion 30b. The first flap portion 50a is The first flap portion 90a of the side wall portion 20c is provided and overlaps with the side wall portion 20a, the second flap portion 50b is provided on the second flap portion 90b of the side wall portion 20c opposite to the first flap portion 90a and overlaps with the side wall portion 20b, the third flap portion 50c is provided on the third flap portion 90c of the side wall portion 20d and overlaps with the side wall portion 20a, and the fourth flap portion 50d is provided on the fourth flap portion 90d of the side wall portion 20d opposite to the third flap portion 90c and overlaps with the side wall portion 20b.

[0055] Therefore, when stacking paper containers 100, it is possible to prevent the paper containers 100 from becoming difficult to separate. Specifically, when stacking paper containers 100, the flap portions 50a, 50b, 50c, and 50d of the lower paper container 100 come into contact with the surface of the side wall portion 20 of the upper paper container 100. The lower paper container 100 does not come into contact with the upper paper container 100 in any part other than the flap portions 50a, 50b, 50c, and 50d. In other words, the lower paper container 100 sandwiches the upper paper container 100 in the direction from the side wall portion 20a to the side wall portion 20b, but does not sandwich the upper paper container 100 in the direction from the side wall portion 20c to the side wall portion 20d. This prevents the paper containers 100 from becoming difficult to separate when stacked.

[0056] For example, if the upper paper container is sandwiched between the lower paper containers from both the first direction and the second direction perpendicular to the first direction, the lower and upper paper containers will fit together firmly, making it difficult for the paper containers to come apart.

[0057] In the paper container 100, the first flap portion 50a, the second flap portion 50b, the third flap portion 50c, and the fourth flap portion 50d are separated from each other. Therefore, when the paper containers 100 are stacked, a gap is created between the flap portions 50a and 50c, the side wall portion 20 of the lower paper container 100, and the side wall portion 20 of the upper paper container 100. Similarly, a gap is created between the flap portions 50b and 50d, the side wall portion 20 of the lower paper container 100, and the side wall portion 20 of the upper paper container 100. This prevents the paper containers 100 from becoming difficult to separate when stacked.

[0058] In the paper container 100, the length of the folded portion 30a is smaller than the lengths of the folded portions 30c and 30d, and the length of the folded portion 30b is smaller than the lengths of the folded portions 30c and 30d. That is, the flap portion 50 is provided on the side wall portion 20 which is connected to the bottom portion 10 via the folded portion 30 along the short side. Therefore, in the paper container 100, when the paper containers 100 are stacked, a gap can be secured enclosed by the flap portion 50, the side wall portion 20 of the lower paper container 100, and the side wall portion 20 of the upper paper container 100.

[0059] For example, if the flap portion is provided on the side wall portion connected to the bottom via a fold line along the long side, the side wall portion is prone to bending, and when paper containers are stacked, the side wall portion of the lower paper container and the side wall portion of the upper paper container may come into contact, making it impossible to secure a gap enclosed by the flap portion, the side wall portion of the lower paper container, and the side wall portion of the upper paper container.

[0060] In the paper container 100, the first flap portion 50a and the second flap portion 50b are in contact with the lower end of the side wall portion 20c, and the third flap portion 50c and the fourth flap portion 50d are in contact with the lower end of the side wall portion 20d. Therefore, in the paper container 100, the contact area between the flap portions 50a, 50c and the side wall portion 20a, and the contact area between the flap portions 50b, 50d and the side wall portion 20b can be increased. This makes it possible to increase the strength of the tray-type paper substrate 110. In the paper container 100, as described above, a through portion 34 is formed in the fold line portion 30 that is longer than the through portion 31, so even if the flap portions 50a, 50b are extended to the lower end of the side wall portion 20c, the resin film 120 can be sufficiently sucked when attaching the resin film 120 to the paper substrate 110.

[0061] In the paper container 100, the thickness of the resin film 120 is smaller than the thickness of the flap portion 50. Therefore, in the paper container 100, when the paper containers 100 are stacked, a gap can be secured enclosed by the flap portion 50, the side wall portion 20 of the lower paper container 100, and the side wall portion 20 of the upper paper container 100. For example, if the thickness of the resin film is greater than the thickness of the flap portion, the gap may be narrowed by the resin film, and it may not be possible to secure the gap.

[0062] In the paper container 100, the angle θ between the side wall 20 and the bottom 10 is obtuse. Therefore, when stacking the paper containers 100, it is possible to prevent them from becoming difficult to separate.

[0063] In the paper container 100, one of the side wall portions 20a is connected to the bottom portion 10 via a straight folded portion 30a. The folded portion 30a has a first part 33 having a through portion 31 (first through portion) and a non-through portion 32 (first non-through portion), and a second part 36 having a through portion 34 (second through portion) that is longer than the through portion 31. The end of the folded portion 30a is made up of a non-through portion 32.

[0064] As described above, in the paper container 100, the folded portion 30a has a second portion 36 having a through portion 34 that is longer than the through portion 31. Therefore, compared to the case where the second portion is not present, for example, the resin film 120 can be sufficiently sucked when it is sucked from the suction hole 133 formed on the bottom surface of the recess 132 and attached to the paper substrate 110. This improves the adhesion between the paper substrate 110 and the resin film 120. Furthermore, when molding the paper substrate 110, the side wall portion 20 can be easily bent relative to the bottom portion 10.

[0065] Furthermore, in the paper container 100, the end of the folded portion 30a is made of a non-penetrating portion 32, thus ensuring strength. For example, if the end of the folded portion is made of a penetrating portion, the strength will be reduced due to the presence of a penetrating portion at the corner of the bottom. Moreover, if a penetrating portion is present at the corner of the bottom, the contents of the paper container may be visible.

[0066] As described above, the paper container 100 can improve the adhesion between the paper substrate 110 and the resin film 120 while maintaining strength even with the penetrations 31 and 34 provided.

[0067] In the paper container 100, the ratio of the length of the portion with the through-hole 31 and the length of the portion with the through-hole 34 to the length of the folded portion 30a is 60% or more and 90% or less, preferably 75% or more and 85% or less. If this ratio is 60% or more, the resin film 120 can be sufficiently drawn in through the through-holes 31 and 34. If this ratio is 90% or less, the strength of the paper container 100 can be ensured.

[0068] In the paper container 100, the first portion 33 and the second portion 36 are arranged alternately in the folded portion 30a. Therefore, the paper container 100 can uniformly draw in the resin film 120 through the through portions 31 and 34.

[0069] In the paper container 100, the flange portion 60 is connected to the side wall portion 20a via a straight folded portion 70a, and the folded portion 70a has a through portion 71 and a non-through portion 72, with the thickness of the non-through portion 72 being less than half the thickness of the flange portion 60. Therefore, in the paper container 100, the paper base material 110 before molding can be easily bent at the folded portion 70a.

[0070] In the paper container 100, the width W of the flange portion 60 is 5.0 mm or more and 10.0 mm or less. If the width W is 5.0 mm or more, the contact area between the flange portion 60 and the resin film 120 can be increased, and the adhesion force of the resin film 120 to the paper substrate 110 can be increased. If the width W is 10.0 mm or less, the flange portion 60 can be kept parallel to the bottom portion 10.

[0071] The embodiments and variations described above are examples only and are not limited thereto. For example, each embodiment and each variation can be combined as appropriate.

[0072] The present invention is not limited to the embodiments described above, and various further modifications are possible. For example, the present invention includes configurations that are substantially identical to those described in the embodiments. A substantially identical configuration is, for example, a configuration that has the same function, method, and result, or a configuration that has the same purpose and effect. The present invention also includes configurations in which non-essential parts of the configuration described in the embodiments are replaced. Furthermore, the present invention includes configurations that produce the same effects or achieve the same purpose as the configuration described in the embodiments. Furthermore, the present invention includes configurations that add known technology to the configuration described in the embodiments. [Explanation of Symbols]

[0073] 10...Bottom, 20, 20a, 20b, 20c, 20d...Side wall, 22...Opening, 30, 30a, 30b, 30c, 30d...Folded line, 31...Penetration section, 32...Non-penetration section, 33...First section, 34...Penetration section, 35...Non-penetration section, 36...Second section, 50...Flap section, 50a...First flap section, 50b...Second flap section, 50c...Third flap section, 50d...Fourth flap section, 52...Folded line section, 54...Opening, 60...Flange section, 70, 70a...Folded line section, 90a...First edge section, 90b...Second edge section, 90c...Third edge section, 90d...Fourth edge section, 100...Paper container, 110...Paper substrate, 120...Resin film, 122...Non-overlapping section, 130...Mold, 132...Recess, 133...Suction hole, 134...Seal bar

Claims

1. A paper container comprising a tray-shaped paper substrate and a resin film attached to the inner surface of the paper substrate, The aforementioned paper substrate is The bottom and, Multiple side wall portions provided along the periphery of the bottom portion, A flange portion provided along the upper end of the plurality of side wall portions, A flap portion is provided on both edges of a pair of side wall portions among the plurality of side wall portions, Includes, The pair of side walls are connected to the bottom via opposing folded lines, The flap portion overlaps with the pair of side wall portions and adjacent side wall portions, forming the inner surface of the paper substrate. A paper container wherein, of the plurality of side wall portions, the side wall portions other than the pair of side wall portions are not provided with the flap portion.

2. The aforementioned paper substrate is The plurality of side wall portions include a first side wall portion, a second side wall portion, a third side wall portion, and a fourth side wall portion, The flap portion comprises a first flap portion, a second flap portion, a third flap portion, and a fourth flap portion, Includes, The first side wall portion is connected to the bottom portion via the first folded line portion, The second side wall portion is connected to the bottom portion via a second fold line portion opposite to the first fold line portion. The third side wall is connected to the bottom via a third folded line that connects the first folded line and the second folded line. The fourth side wall portion is connected to the bottom portion via a fourth fold line portion opposite to the third fold line portion. The first flap portion is provided on the first edge of the third side wall portion and overlaps with the first side wall portion. The second flap portion is provided on the second edge of the third side wall portion opposite to the first edge portion, and overlaps with the second side wall portion. The third flap portion is provided on the third edge of the fourth side wall portion and overlaps with the first side wall portion. The paper container according to claim 1, wherein the fourth flap portion is provided on the fourth edge of the fourth side wall portion opposite to the third edge portion and overlaps with the second side wall portion.

3. The paper container according to claim 2, wherein the first flap portion, the second flap portion, the third flap portion, and the fourth flap portion are separated from each other.

4. The length of the first folded portion is smaller than the lengths of the third folded portion and the fourth folded portion. The paper container according to claim 3, wherein the length of the second fold line portion is smaller than the lengths of the third fold line portion and the fourth fold line portion.

5. The first flap portion and the second flap portion are in contact with the lower end of the third side wall portion, The paper container according to claim 2 or 3, wherein the third flap portion and the fourth flap portion are in contact with the lower end of the fourth side wall portion.

6. The paper container according to claim 1 or 2, wherein the thickness of the resin film is less than the thickness of the flap portion.

7. The paper container according to claim 1 or 2, wherein the angle of the side wall portion with respect to the bottom portion is obtuse.

8. The first folded portion is, A first portion having a first penetrating portion and a first non-penetrating portion, A second portion having a second through-hole that is longer than the first through-hole, It has, The paper container according to claim 5, wherein the end of the first folded portion is formed by the first non-penetrating portion.

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