Blanks, paper containers and paper containers with lids

Abstract

To provide a blank material, a paper container, and a paper container with a lid material which are capable of improving the strength of the paper container and protecting a formed film.SOLUTION: A blank 30 includes a bottom part panel 31, a plurality of side part panels 33 connected to the bottom part panel 31 via a first folding line 32, and a plurality of flange piece panels 35 each connected to each side part panel 33 via a second folding line 34. A gap 36 is formed between the side part panels 33. A first recess 81 is formed in one side part panel 33. A first projection 82 that is stored in the first recess 81 is formed on the other side part panel 33 that faces the one side part panel 33 with the gap 36 interposed therebetween.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a blank, a paper container, and a paper container with a lid. [Background technology]

[0002] BACKGROUND ART Containers for storing food and drink to be taken home (so-called take-out products) and food and drink to be delivered to home have been known.

[0003] In recent years, in order to address the problem of marine pollution and reduce the environmental load, there has been a demand for reducing the amount of resin used in such containers, and efforts are being made to reduce the amount of resin and change the materials used in the containers. As such a container, a paper container comprising a paper container and a formed film laminated on the inner wall of the paper container is known (for example, Patent Document 1). In such a paper container, after food is filled, the paper container is covered with a lid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2013-545675 Summary of the Invention [Problem to be solved by the invention]

[0005] However, such paper containers are manufactured by assembling blanks, which may result in a decrease in the strength of the paper container. For this reason, it is desirable to improve the strength of paper containers.

[0006] Furthermore, because paper containers are made by assembling blanks, there is a possibility that the formed film may be exposed between the side panels, for example. In this case, there is a possibility that the formed film may be contacted from the outside of the paper container, so a paper container that can protect the formed film is desired.

[0007] The present disclosure has been made in consideration of these points, and aims to provide a blank material, a paper container, and a paper container with a lid material that can improve the strength of the paper container and protect the formed film. [Means for solving the problem]

[0008] A blank material according to one embodiment comprises a bottom panel, a plurality of side panels connected to the bottom panel via a first fold line, and a plurality of flange piece panels connected to each of the side panels via a second fold line, wherein a gap is formed between the side panels, a first recess is formed in one of the side panels, and a first protrusion that is accommodated in the first recess is formed in another side panel that faces the first side panel across the gap.

[0009] In the blank according to one embodiment, the first protrusion may engage with the first recess.

[0010] In one embodiment, the first convex portion may include at least a widened portion whose width gradually increases from the base end side toward the tip end side.

[0011] In one embodiment, at least a part of the outline of the first protrusion may have an arc shape in plan view.

[0012] In one embodiment of the blank, a second recess may be formed in the other side panel, and a second protrusion may be formed in the one side panel that is accommodated in the second recess.

[0013] A paper container according to one embodiment is a paper container comprising a paper container produced by assembling the blank material according to the present disclosure and a formed film laminated on the surface of the paper container.

[0014] A paper container according to one embodiment comprises a paper container having a bottom, a plurality of side portions connected to the bottom via a first fold line, and a plurality of flange pieces connected to each side portion via a second fold line, and a molded film laminated on the surface of the paper container, wherein the side portions are adjacent to each other without being continuous with each other, a first recess is formed in one side portion, and a first convex portion that is accommodated in the first recess is formed in the other side portion adjacent to the one side portion.

[0015] In the paper container according to one embodiment, the first protrusion may be engaged with the first recess.

[0016] In one embodiment, the first convex portion may include at least a widened portion whose width gradually increases from the base end side toward the tip end side.

[0017] In one embodiment, at least a part of the outline of the first convex portion may have an arc shape in side view.

[0018] In one embodiment of the paper container, a second recess may be formed in the other side portion, and a second protrusion that is accommodated in the second recess may be formed in the one side portion.

[0019] A paper container with a lid according to one embodiment is a paper container with a lid comprising the paper container according to the present disclosure and a lid that seals the paper container. [Effects of the Invention]

[0020] According to the present disclosure, the strength of the paper container can be improved and the formed film can be protected. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a vertical cross-sectional view showing a paper container with a lid according to this embodiment. [Figure 2] FIG. 2 is a perspective view showing a paper container according to this embodiment. [Figure 3] FIG. 3 is a plan view showing the paper container according to this embodiment. [Figure 4A] FIG. 4A is a side view (view taken along the arrow IVA in FIG. 2) showing the paper container according to this embodiment. [Figure 4B] FIG. 4B is a side view showing the paper container according to the present embodiment. [Figure 4C] FIG. 4C is a perspective view (view taken along the arrow IVC in FIG. 2) showing the paper container according to the present embodiment. [Figure 4D] FIG. 4D is a side view (corresponding to FIG. 4A) showing a comparative example of the paper container according to the present embodiment. [Figure 4E] FIG. 4E is a perspective view (corresponding to FIG. 4C) showing a paper container as a comparative example of the paper container according to the present embodiment. [Figure 5] FIG. 5 is a plan view showing a blank according to this embodiment. [Figure 6] FIG. 6 is an enlarged plan view showing a blank according to this embodiment (an enlarged plan view corresponding to part VI in FIG. 5). [Figure 7] FIG. 7 is a cross-sectional view showing a method for manufacturing a paper container according to this embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a method for manufacturing a paper container according to this embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing a method for manufacturing a paper container according to this embodiment. [Figure 10] FIG. 10 is a cross-sectional view illustrating the function of the paper container according to this embodiment. [Figure 11] FIG. 11 is a cross-sectional view illustrating the function of the paper container according to this embodiment. [Figure 12A] FIG. 12A is a side view (corresponding to FIG. 4B) showing a first modified example of the paper container according to the present embodiment. [Figure 12B] FIG. 12B is an enlarged perspective view (corresponding to FIG. 4C) showing a first modified example of the paper container according to the present embodiment. [Figure 13]FIG. 13 is an enlarged plan view (corresponding to FIG. 6) showing a first modified example of the blank according to the present embodiment. [Figure 14A] FIG. 14A is a side view (corresponding to FIG. 4B) showing another example of the first modified paper container according to the present embodiment. [Figure 14B] FIG. 14B is an enlarged perspective view (corresponding to FIG. 4C) showing another example of the first modified paper container of the paper container according to the present embodiment. [Figure 15] FIG. 15 is an enlarged plan view (corresponding to FIG. 6) showing another example of the first modified example of the blank piece according to the present embodiment. [Figure 16A] FIG. 16A is a side view (corresponding to FIG. 4B) showing a second modified example of the paper container according to the present embodiment. [Figure 16B] FIG. 16B is an enlarged perspective view (corresponding to FIG. 4C) showing a second modified example of the paper container according to the present embodiment. [Figure 17] FIG. 17 is an enlarged plan view (corresponding to FIG. 6) showing a second modified example of the blank according to the present embodiment. [Figure 18A] FIG. 18A is a side view (corresponding to FIG. 4B) showing a third modified example of the paper container according to the present embodiment. [Figure 18B] FIG. 18B is an enlarged perspective view (corresponding to FIG. 4C) showing a third modified example of the paper container according to the present embodiment. [Figure 19] FIG. 19 is an enlarged plan view (corresponding to FIG. 6) showing a third modified example of the blank according to the present embodiment. [Figure 20A] FIG. 20A is a side view (corresponding to FIG. 4B) showing another example of the third modified paper container according to the present embodiment. [Figure 20B] FIG. 20B is an enlarged perspective view (corresponding to FIG. 4C) showing another example of the third modified paper container of the paper container according to the present embodiment. [Figure 21] FIG. 21 is an enlarged plan view (corresponding to FIG. 6) showing another example of the third modified example of the blank according to the present embodiment. [Figure 22A] FIG. 22A is a side view (corresponding to FIG. 4B) showing a fourth modified example of the paper container according to the present embodiment. [Figure 22B] FIG. 22B is an enlarged perspective view (corresponding to FIG. 4C) showing a fourth modified example of the paper container according to the present embodiment. [Figure 23] FIG. 23 is an enlarged plan view (corresponding to FIG. 6) showing a fourth modified example of the blank according to the present embodiment. [Figure 24A] FIG. 24A is a side view (corresponding to FIG. 4B) showing another example of the fourth modified paper container according to the present embodiment. [Figure 24B] FIG. 24B is an enlarged perspective view (corresponding to FIG. 4C) showing another example of the fourth modified paper container according to the present embodiment. [Figure 25] FIG. 25 is an enlarged plan view (corresponding to FIG. 6) showing another example of the fourth modified example of the blank according to the present embodiment. [Figure 26A] FIG. 26A is a side view (corresponding to FIG. 4B) showing another example of the fourth modified paper container according to the present embodiment. [Figure 26B] FIG. 26B is an enlarged perspective view (corresponding to FIG. 4C) showing another example of the fourth modified paper container according to the present embodiment. [Figure 27] FIG. 27 is an enlarged plan view (corresponding to FIG. 6) showing another example of the fourth modified example of the blank according to the present embodiment. [Figure 28A] FIG. 28A is a side view (corresponding to FIG. 4B) showing another example of the fourth modified paper container according to the present embodiment. [Figure 28B] FIG. 28B is an enlarged perspective view (corresponding to FIG. 4C) showing another example of the fourth modified paper container according to the present embodiment. [Figure 29] FIG. 29 is an enlarged plan view (corresponding to FIG. 6) showing another example of the fourth modified example of the blank according to the present embodiment. [Figure 30] FIG. 30 is a diagram illustrating a strength measurement test according to an embodiment. [Figure 31] FIG. 31 is a plan view (corresponding to FIG. 5) showing a blank material of a comparative example in the example. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present embodiment will now be described with reference to the drawings. Figures 1 to 11 illustrate the present embodiment. The following figures are schematic illustrations. Therefore, the size and shape of each part are appropriately exaggerated for ease of understanding. Appropriate modifications are possible within the scope of the technical concept. In the following figures, identical parts are denoted by the same reference numerals, and some detailed descriptions may be omitted. The numerical values, such as dimensions, and material names of each component described in this specification are merely examples of the embodiment and are not limited to these. Appropriate selections may be made. In this specification, terms specifying shape or geometric conditions, such as parallel, perpendicular, and vertical, are used in their strict sense, but also encompass substantially the same state. In this specification, "top" and "bottom" refer to the upper and lower sides, respectively, of a paper container in an upright position (Figure 1). In this specification, "surface" refers to the surface facing the contents or the surface facing upward when the paper container is upright.

[0023] Paper container with lid As shown in Fig. 1, the paper container with lid 1 according to this embodiment comprises a paper container 10 and a lid 50 that seals the paper container 10. First, the paper container 10 will be described.

[0024] Paper containers 1 to 3, the paper container 10 includes a paper container 20 and a formed film 40 laminated on the surface of the paper container 20. The paper container 20 is produced by assembling blanks 30, which will be described later.

[0025] (Paper container) The paper container 20 has a bottom 21, a plurality of side portions 23 connected to the bottom 21 via a first fold line 22, and a plurality of flange pieces 25 connected to each of the side portions 23 via a second fold line 24.

[0026] The bottom 21 has a generally rectangular shape in plan view. The bottom 21 may have a polygonal shape such as an octagonal shape in plan view.

[0027] The first fold line 22 connecting the bottom portion 21 and the side portion 23 may be formed in a perforated shape or a half-cut line. This makes it easier to fold the side portion 23 relative to the bottom portion 21. When the first fold line 22 is formed in a perforated shape, the formed film 40 is pressed against the paper container 20 in the vicinity of the first fold line 22 by sucking air through suction holes 61 of the cavity-side mold 60, which will be described later. This improves the adhesion between the formed film 40 and the paper container 20.

[0028] Each side portion 23 extends upward from the bottom portion 21. In the illustrated example, the paper container 20 has four side portions 23. Specifically, the paper container 20 has a pair of first side portions 23a extending along the short sides of the rectangle defined by the bottom portion 21 and a pair of second side portions 23b extending along the long sides of the rectangle defined by the bottom portion 21, and the side portions 23 are formed as a whole in the shape of an inverted quadrangular pyramid. However, this is not limited thereto, and the side portions 23 may be formed as a whole in the shape of a polygonal pyramid, such as an inverted octagonal pyramid.

[0029] The multiple side portions 23 are adjacent to each other without being continuous with each other. That is, the side portions 23 are adjacent to each other without overlapping. This improves the adhesion between the side portions 23 and the formed film 40 around the entire circumference of the paper container 20. Furthermore, because the side portions 23 are adjacent to each other without overlapping, it is possible to prevent pinholes and the like from occurring in the formed film 40 when the formed film 40 is bonded to the paper container 20. Note that small gaps are formed between the side portions 23 to allow air to pass through, and the formed film 40 is configured to be pressed against the paper container 20 by sucking air through suction holes 61 of the cavity-side mold 60, which will be described later.

[0030] The second fold line 24 connecting the side portion 23 and the flange piece 25 may be formed in a perforated shape, similar to the first fold line 22, or may be a half-cut line. This makes it easier to fold the flange piece 25 relative to the side portion 23. When the second fold line 24 is formed in a perforated shape, the formed film 40 is pressed against the paper container 20 in the vicinity of the second fold line 24 by sucking air through suction holes 61 of the cavity-side mold 60, which will be described later. This improves the adhesion between the formed film 40 and the paper container 20.

[0031] Each flange piece 25 protrudes horizontally from the upper end of the side portion 23. In the illustrated example, the paper container 20 has four flange pieces 25. Specifically, the paper container 20 has a pair of first flange pieces 25a extending along the short sides of the rectangle defined by the bottom portion 21 and a pair of second flange pieces 25b extending along the long sides of the rectangle defined by the bottom portion 21, and the flange pieces 25 are formed in an annular shape as a whole.

[0032] The multiple flange pieces 25 are adjacent to each other without being contiguous. That is, the flange pieces 25 are adjacent to each other without overlapping. This improves the adhesion between the flange pieces 25 and the molded film 40 around the entire circumference of the paper container 20. Furthermore, because the flange pieces 25 are adjacent to each other without overlapping, it is possible to prevent pinholes and the like from occurring in the molded film 40 when adhering the molded film 40 to the paper container 20. Furthermore, because the flange pieces 25 are adjacent to each other without overlapping, it is possible to improve the adhesion between the molded film 40 and the lid material 50 when sealing the lid material 50 to the area of ​​the molded film 40 of the paper container 10 that corresponds to the flange pieces 25. This prevents poor sealing of the lid material 50. In this specification, "adjacent" refers not only to the case where adjacent members (e.g., flange pieces 25) are in contact with each other without any gaps throughout, but also to the case where either (1) or (2) below applies. (1) One member and another member are adjacent to each other with only a portion of the one member (for example, the first flange piece 25a) in contact with the other member (for example, the second flange piece 25b). (2) When one component (e.g., first flange piece 25a) and another component (e.g., second flange piece 25b) are adjacent to each other without being in contact with each other, at least a portion of the gap between the one component and the other component is large enough that the molded film 40 (film 40a described below) cannot penetrate when adhering the molded film 40 to the one component and the other component.

[0033] 3 to 4C, a first recess 71 is formed in one side portion 23, and a first protrusion 72 that is housed in the first recess 71 is formed in another side portion 23 adjacent to the first side portion 23. In the example shown, the first recess 71 is formed in the first side portion 23a, and the first protrusion 72 is formed in the second side portion 23b. The first recess 71 and the first protrusion 72 serve to increase the strength of the paper container 10. In other words, by housing the first protrusion 72 in the first recess 71, deformation of the side portion 23 can be suppressed when a force is applied to the paper container 10 in the vertical direction.

[0034] 4D, in a paper container 10A including a paper container 20A in which the first recesses 71 and first protrusions 72 are not formed on the side portions 23, the side portions 23 may be easily crushed when a force F (hereinafter simply referred to as force F) is applied to the paper container 10A in the vertical direction. Furthermore, if the side portions 23 are crushed or deformed, the side edges 23c of adjacent side portions 23 may separate from each other. In this case, the molded film 40 may be exposed to the outside between the side edges 23c of adjacent side portions 23.

[0035] In contrast, in the present embodiment, as described above, a first recess 71 is formed in one side portion 23, and a first protrusion 72 that is housed in the first recess 71 is formed in another side portion 23 adjacent to the one side portion 23. In this case, when force F is applied to the paper container 10 and the side portion 23 attempts to deform, the first recess 71 and the first protrusion 72 interfere with each other. This prevents the side portion 23 from deforming.

[0036] Furthermore, in this case, by accommodating the first protrusion 72 within the first recess 71, even if a gap is formed between the side edges 23c of adjacent side portions 23, the length of the portion of the gap that extends linearly, for example, vertically, can be shortened. In other words, the shape of the gap can be made complex. This prevents surrounding structures and the like from coming into contact with the molded film 40 from the outside during transport of the paper container 10. Here, near the side edges 23c of the side portions 23, the film 40a (described later) constituting the molded film 40 may be stretched, resulting in the molded film 40 becoming thinner than other portions. Thus, even if the molded film 40 becomes thinner than other portions, in this embodiment, it is possible to prevent surrounding structures and the like from coming into contact with the molded film 40 from the outside, thereby preventing the thinned molded film 40 from being torn.

[0037] Such first recesses 71 are formed at both longitudinal end portions (vertical direction in FIG. 3) of the first side portion 23a, and two first recesses 71 are formed on each first side portion 23a. Similarly, first protrusions 72 are formed on longitudinal end portions (horizontal direction in FIG. 3) of the second side portion 23b, and two first protrusions 72 are formed on each second side portion 23b. As shown in FIGS. 4A to 4C, the first recesses 71 and the first protrusions 72 are formed at positions spaced apart from the first fold line 22 and the second fold line 24, respectively. Specifically, the first recesses 71 and the first protrusions 72 are formed approximately in the centers of the side edges 23c of the side portions 23.

[0038] In this embodiment, the first protrusions 72 engage with the first recesses 71. This effectively prevents the side portions 23 from being deformed. Furthermore, by having the first protrusions 72 engage with the first recesses 71, the shape of the gap that may be formed between the side edges 23c can be made more complex. This effectively prevents surrounding structures and the like from coming into contact with the molded film 40 from the outside when the paper container 10 is being transported, etc.

[0039] Furthermore, the engagement of the first protrusion 72 with the first recess 71 effectively suppresses relative movement between the first side portion 23a and the second side portion 23b. This also suppresses relative movement between the first flange piece 25a and the second flange piece 25b. In this case, the first recess 71 and the first protrusion 72 suppress relative movement between the first flange piece 25a and the second flange piece 25b, thereby preventing a gap from forming between the first flange piece 25a and the second flange piece 25b, extending from the outer edge 25c to the inner edge 25d of the first flange piece 25a (second flange piece 25b). In the following description, the gap between the first flange piece 25a and the second flange piece 25b, extending from the outer edge 25c to the inner edge 25d of the first flange piece 25a (second flange piece 25b), will also be referred to simply as "gap G."

[0040] On the other hand, as shown in Figure 4E, in the case of a paper container 20A in which the side portion 23 does not have the first recess 71 and the first protrusion 72, the first side portion 23a (second side portion 23b) easily moves in a direction away from the second side portion 23b (first side portion 23a), which may cause the first flange piece 25a (second flange piece 25b) to easily move in a direction away from the second flange piece 25b (first flange piece 25a). In this case, a gap G may be formed between the first flange piece 25a and the second flange piece 25b, extending from the outer edge 25c to the inner edge 25d of the first flange piece 25a (second flange piece 25b). In this case, as will be described later, a gap g2 (see Figure 10) may be formed between the formed film 40 and the lid member 50, which may connect the inside and outside of the lid-equipped paper container 1, and may make it impossible to seal the lid-equipped paper container 1.

[0041] In contrast, in the present embodiment, as described above, the first protrusion 72 engages with the first recess 71. This effectively suppresses relative movement between the first side portion 23a and the second side portion 23b, and suppresses relative movement between the first flange piece 25a and the second flange piece 25b. This prevents the gap G from being formed between the first flange piece 25a and the second flange piece 25b.

[0042] 4A to 4C, the first recess 71 includes an enlarged portion 73 whose width gradually increases as the depth of the first recess 71 increases, and a reduced portion 74 whose width gradually decreases as the depth of the first recess 71 increases. Meanwhile, the first protrusion 72 includes an enlarged portion 75 whose width gradually increases from the base end 72a toward the tip 72b, and a reduced portion 76 whose width gradually decreases from the base end 72a toward the tip 72b. As a result, when the first side portion 23a (second side portion 23b) attempts to move in a direction away from the second side portion 23b (first side portion 23a), the enlarged portion 73 of the first recess 71 interferes with the enlarged portion 75 of the first protrusion 72. This effectively suppresses relative movement between the first side portion 23a and the second side portion 23b.

[0043] Furthermore, at least a portion of the contour of the first recess 71 has an arc shape in side view. Similarly, at least a portion of the contour of the first protrusion 72 has an arc shape in side view. This prevents interference between the first protrusion 72 and the portion of the first side portion 23a surrounding the first recess 71 when the first protrusion 72 is accommodated in the first recess 71, making it easier to engage the first protrusion 72 with the first recess 71. In this embodiment, the contours of the enlarged portion 73 and the reduced portion 74 of the first recess 71 each have an arc shape in side view. Similarly, the contours of the widened portion 75 and the narrowed portion 76 of the first protrusion 72 each have an arc shape in side view.

[0044] (Blank material) Next, a blank 30 for producing the paper container 20 will be described. As shown in Fig. 5, the blank 30 includes a bottom panel 31, a plurality of side panels 33 connected to the bottom panel 31 via first fold lines 32, and a plurality of flange piece panels 35 connected to each of the side panels 33 via second fold lines 34. The bottom panel 31, first fold line 32, side panels 33, second fold line 34, and flange piece panels 35 of the blank 30 correspond to the bottom 21, first fold line 22, side portions 23, second fold line 24, and flange pieces 25 of the paper container 20, respectively. In the illustrated example, the blank 30 includes four side panels 33 and four flange piece panels 35.

[0045] A gap 36 is formed between the side panels 33. In this case, each side panel 33 is formed in a trapezoidal shape. Each side panel 33 has a pair of side edges 33c extending from the bottom panel 31. A gap 36 is formed between the side edges 33c of the side panels 33. As a result, in the paper container 10 described above, the side portions 23 do not overlap each other but are adjacent to each other (see FIGS. 2 and 3). In the illustrated example, in each side panel 33, the pair of side edges 33c extend in directions that move away from each other from the first fold line 32 side toward the second fold line 34 side.

[0046] As described above, the side panels 33 of the blank 30 correspond to the sides 23 of the paper container 20. Therefore, the blank 30 has a pair of first side panels 33a extending along the short sides of the rectangle defined by the bottom panel 31, and a pair of second side panels 33b extending along the long sides of the rectangle defined by the bottom panel 31.

[0047] As described above, the flange piece panels 35 of the blank 30 correspond to the flange pieces 25 of the paper container 20. Therefore, the blank 30 has a pair of first flange piece panels 35a extending along the short sides of the rectangle defined by the bottom panel 31, and a pair of second flange piece panels 35b extending along the long sides of the rectangle defined by the bottom panel 31.

[0048] 5 and 6, a first recess 81 is formed in one side panel 33, and a first protrusion 82 that is housed in the first recess 81 is formed in another side panel 33 that faces the first side panel 33 across a gap 36. In the illustrated example, the first recess 81 is formed in the first side panel 33a, and the first protrusion 82 is formed in the second side panel 33b. The first recess 81 and the first protrusion 82 are each formed approximately in the center of the side edge 33c of the side panel 33.

[0049] The first recess 81 and the first protrusion 82 correspond to the first recess 71 and the first protrusion 72 of the side portion 23 of the paper container 20, respectively. Therefore, the first protrusion 82 is configured to engage with the first recess 81. Furthermore, as shown in FIG. 6, the first recess 81 includes an enlarged portion 83 corresponding to the enlarged portion 73 of the first recess 71 of the side portion 23, and a reduced portion 84 corresponding to the reduced portion 74. Similarly, the first protrusion 82 includes an enlarged portion 85 (the enlarged portion 85 gradually widens from the base end 82a toward the tip 82b) corresponding to the enlarged portion 75 of the first protrusion 72 of the side portion 23, and a reduced width portion 86 (the reduced width portion 86 gradually narrows from the base end 82a toward the tip 82b) corresponding to the reduced width portion 76. Furthermore, in a plan view, at least a portion of the outline of the first recess 81 has an arc shape, and at least a portion of the outline of the first protrusion 82 has an arc shape. In this embodiment, the contours of the enlarged portion 83 and the narrowed portion 84 of the first recessed portion 81 each have an arc shape in plan view. Similarly, the contours of the widened portion 85 and the narrowed portion 86 of the first protrusion 82 each have an arc shape in plan view.

[0050] The bottom panel 31, the side panels 33, and the flange piece panel 35 of the blank 30 are integrally formed. The blank 30 can be produced by punching or the like the paper material that constitutes the blank 30.

[0051] The blank 30 is made of a paper material having a basis weight of 150 g / m. 2 More than 800g / m 2 Various types of paperboard, coated paper, card paper, ivory paper, milk carton base paper, cup base paper, coated cardboard, and other processed paper can be used.

[0052] (molded film) Next, the formed film 40 will be described with reference to Figures 1 to 4B. This formed film 40 serves to protect the paper container 20. The formed film 40 has a container shape and covers the entire surface of the paper container 20. This prevents the contents filled in the paper container 10 from leaking out of the paper container 10. The formed film 40 is adhered to the paper container 20 by, for example, heat sealing (thermal welding).

[0053] Such a formed film 40 may be any film made of a thermoplastic resin that is water-resistant, airtight, and heat-sealable. Examples of the formed film 40 include polyethylene (PE), polypropylene (PP), polyvinyl chloride, polyethylene terephthalate (PET), ethylene-vinyl acetate copolymer, ionomer, ethylene-acrylic acid copolymer, polyamide, polyvinylidene chloride, polystyrene, saponified ethylene-vinyl acetate copolymer, polycarbonate, polybutene, polyvinyl alcohol, and other thermoplastic resin films, either alone or laminated together. In particular, when gas barrier properties are desired for the paper container 10, a laminate having a gas barrier material such as ethylene-vinyl alcohol copolymer (EVOH) laminated as an intermediate layer can be used, specifically a laminate having a layer structure such as PE / EVOH / PE, PP / EVOH / PE, or A (amorphous) PET / EVOH / PE.

[0054] The formed film 40 may be made from a laminate having the following layer configuration, for example. (Outside) Polyethylene (40 μm) / Ionomer (40 μm) / Polyethylene (40 μm) (Inside) (Outside) Polypropylene (30 μm) / Adhesive layer (10 μm) / Ionomer (40 μm) / Adhesive layer (10 μm) / Polypropylene (30 μm) (Inside) (Outside) Polyethylene (20 μm) / Ionomer (30 μm) / Adhesive layer (10 μm) / Ethylene-vinyl alcohol copolymer (10 μm) / Adhesive layer (10 μm) / Ionomer (15 μm) / Ethylene-vinyl acetate copolymer (20 μm) (Inside)

[0055] Each of the above layers is formed by a conventional method such as dry lamination, extrusion lamination, extrusion coating or other coating method.

[0056] Lid material Next, a description will be given of the lid member 50. The lid member 50 is sealed over the entire periphery of the region of the forming film 40 of the paper container 10 that corresponds to the flange piece 25.

[0057] The lid material 50 may be a laminate having a layer structure such as PET / sealant layer, PP / sealant layer, PET / PP / sealant layer, PET / PE / sealant layer, or K-coated oriented nylon (KON) / PE / sealant layer. The laminate constituting the lid material 50 may also be a laminate having a gas barrier material such as ethylene-vinyl alcohol copolymer (EVOH) laminated as an intermediate layer. The lid material 50 may be a laminate having a layer structure such as PET / PE / ethylene-vinyl alcohol copolymer (EVOH) / PE / sealant layer. Aluminum foil or a vapor-deposited film (aluminum vapor deposition or transparent vapor deposition) may also be used as the barrier layer. It is preferable to use a resin material capable of exhibiting so-called easy-peel properties for the sealant.

[0058] The lid member 50 may be made from a laminate having the following layer configuration, for example. (Outside) Polyethylene terephthalate film with transparent vapor deposition layer (12 μm) / Nylon film (15 μm) / Polyethylene film (40 μm) (Inside)

[0059] Each of the above layers is formed by a conventional method such as dry lamination, extrusion lamination, extrusion coating or other coating method.

[0060] In the paper container with lid 1 configured as described above, first, the contents are filled into the paper container 10. Next, the lid 50 is sealed to the area of ​​the forming film 40 of the paper container 10 that corresponds to the flange piece 25. This results in a paper container with lid 1 filled with the contents. The paper container with lid 1 may be a container for chilled foods or frozen foods, or may be used as a take-out container. The contents may also be food such as prepared dishes, meat, or dairy products.

[0061] Next, the operation of this embodiment configured as described above will be explained. Here, a method for manufacturing the paper container 10 and a method for manufacturing the paper container with lid 1 will be explained with reference to Figs. 7 to 11.

[0062] Paper container manufacturing method First, prepare the blank material 30. In this case, first, a paper material is prepared, and then the blank material 30 is obtained by performing a punching process or the like on the paper material.

[0063] Next, as shown in FIG. 7, the blank 30 is attached to the cavity-side mold 60. Suction holes 61 are formed in the cavity-side mold 60, and the blank 30 is attached to the cavity-side mold 60 by sucking air through the suction holes 61. At this time, the side panels 33 of the blank 30 are folded relative to the bottom panel 31 along the first fold line 32. Similarly, the flange piece panels 35 of the blank 30 are folded relative to the side panels 33 along the second fold line 34. At this time, the first protrusions 82 formed on the second side panels 33b are accommodated in the first recesses 81 formed in the first side panels 33a. This results in a paper container 20 attached to the cavity-side mold 60.

[0064] Next, the formed film 40 is laminated on the surface of the paper container 20. At this time, first, as shown in FIG. 8, the film 40a that constitutes the formed film 40 is placed above the paper container 20. Next, the film 40a is heated by the core side mold 62 (see FIG. 9). Then, after the film 40a has been sufficiently heated by the core side mold 62, air is sucked through the suction holes 61. As a result, the film 40a is sucked onto the paper container 20, as shown in FIG. 9. At this time, the core side mold 62 also presses the film 40a against the paper container 20. As a result, the film 40a is in close contact with the paper container 20.

[0065] The film 40a is then cut into a desired shape by a cutting mechanism 63 provided in the core-side mold 62. This results in a formed film 40 laminated on a paper container 20, as shown in Figure 9. In this way, a paper container 10 is obtained.

[0066] In the paper container 20, the first convex portion 72 formed on the second side portion 23b engages with the first concave portion 71 formed on the first side portion 23a. This suppresses relative movement of the first flange piece 25a with respect to the second flange piece 25b (relative movement of the second flange piece 25b with respect to the first flange piece 25a). This suppresses the formation of a gap (i.e., gap G) extending from the outer edge 25c to the inner edge 25d of the first flange piece 25a (second flange piece 25b) between the first flange piece 25a and the second flange piece 25b.

[0067] 10, if a gap g1 is formed between the first flange piece 25a and the second flange piece 25b, the film 40a may enter the gap g1, forming a depression 40b on the surface of the film 40a. If a depression 40b is formed on the surface of the film 40a in this way, a gap g2 may be formed between the formed film 40 obtained from the film 40a and the lid material 50. If the gap g1 between the first flange piece 25a and the second flange piece 25b extends from the outer edge 25c to the inner edge 25d of the first flange piece 25a (second flange piece 25b) (i.e., if the gap g1 is gap G), the gap g2 between the formed film 40 and the lid material 50 will cause communication between the inside and outside of the paper container with lid 1, making it impossible to seal the paper container with lid 1.

[0068] In contrast, in the present embodiment, as described above, the formation of gap G between first flange piece 25a and second flange piece 25b is suppressed. This makes it possible to suppress the formation of a depression in the surface of film 40a, as shown in Fig. 11, and to make the surface of film 40a flat. Therefore, as will be described later, the formation of gap g2 described above between molded film 40 and lid member 50 can be suppressed.

[0069] Next, a method for manufacturing the lidded paper container 1 will be described.

[0070] First, the lid material 50 is prepared in parallel with the production of the paper container 10. At this time, a predetermined laminate is produced by a dry lamination method or the like. Then, the laminate is punched into a predetermined shape with a blade or the like to produce the lid material 50.

[0071] Next, the paper container 10 is filled with the contents, and the paper container 10 is sealed with the lid member 50. At this time, first, the contents (not shown) are filled into the paper container 10. Next, the lid member 50 is placed on the forming film 40 at a position corresponding to the flange piece 25.

[0072] Next, the lid material 50 is sealed to the formed film 40 by a sealing hot plate (not shown) or the like. At this time, the air inside the paper container 10 may be replaced with nitrogen gas or the like.

[0073] As described above, the surface of the formed film 40 is flat (see FIG. 11). This prevents the formation of a gap g2 (see FIG. 10) between the formed film 40 and the lid member 50, and the paper container with lid member 1 is sealed.

[0074] In this way, a paper container with lid 1 is obtained, which comprises the paper container 10 and the lid 50 that seals the paper container 10.

[0075] As described above, according to this embodiment, a first recess 71 is formed in the first side portion 23a (one side portion 23), and a first protrusion 72 that is housed in the first recess 71 is formed in the second side portion 23b (another side portion 23) adjacent to the first side portion 23a. As a result, when force F is applied to the paper container 10 and the side portion 23 attempts to deform, the first recess 71 and the first protrusion 72 interfere with each other. This prevents the side portion 23 from deforming. This improves the strength of the paper container 10. Furthermore, by housing the first protrusion 72 in the first recess 71, the shape of the gap that may be formed between the side edges 23c can be made complex. This prevents surrounding structures and the like from coming into contact with the molded film 40 from the outside during transportation of the paper container 10, etc. Therefore, the first protrusion 72 can protect the molded film 40.

[0076] Furthermore, according to this embodiment, the first convex portion 72 engages with the first concave portion 71. This effectively prevents the side portion 23 from being deformed. Furthermore, by having the first convex portion 72 engage with the first concave portion 71, the shape of the gap that may be formed between the side edges 23c can be made more complex. This effectively prevents surrounding structures and the like from coming into contact with the molded film 40 from the outside when the paper container 10 is being transported, etc.

[0077] Furthermore, by engaging the first convex portion 72 with the first concave portion 71, relative movement between the first flange piece 25a and the second flange piece 25b can be suppressed. This prevents a gap G from being formed between the first flange piece 25a and the second flange piece 25b. This improves the airtightness of the lidded paper container 1. By improving the airtightness of the lidded paper container 1 in this way, the barrier properties of the lidded paper container 1 can be improved, and the life of the contents can be extended. As a result, food waste can also be reduced.

[0078] Furthermore, according to the present embodiment, the first convex portion 72 includes a widened portion 75 and a narrowed portion 76 that is provided closer to the tip 72b than the widened portion 75 and is wider than the widened portion 75. As a result, when the first side portion 23a (the second side portion 23b) attempts to move in a direction away from the second side portion 23b (the first side portion 23a), the first convex portion 72 interferes with the first recessed portion 71. As a result, it is possible to more effectively suppress the relative movement between the first side portion 23a and the second side portion 23b.

[0079] Furthermore, according to the present embodiment, at least a portion of the outline of first protrusion 72 has an arc shape in side view. This prevents first protrusion 72 from interfering with the portion of first side portion 23a surrounding first recess 71 when first protrusion 72 is accommodated in first recess 71, making it easier to engage first protrusion 72 with first recess 71.

[0080] Variations Next, modified examples of the paper container 10 and blank 30 according to this embodiment will be described with reference to Figures 12A to 29. In Figures 12A to 29, the same parts as those in the embodiment shown in Figures 1 to 11 are designated by the same reference numerals, and detailed descriptions thereof will be omitted.

[0081] (First Modification) In the above-described embodiment, an example has been described in which the contours of the enlarged portions 73, 83 and the reduced portions 74, 84 of the first recessed portions 71, 81 each have an arc shape in a side view or a plan view, but this is not limited to this. Similarly, an example has been described in which the contours of the enlarged portions 75, 85 and the reduced portions 76, 86 of the first protrusions 72, 82 each have an arc shape in a side view or a plan view, but this is not limited to this. For example, the contours of the first recessed portions 71, 81 may each have a shape that combines an arc shape and a linear shape in a side view or a plan view, and the contours of the first protrusions 72, 82 may each have a shape that combines an arc shape and a linear shape in a side view or a plan view.

[0082] In this case, as shown in FIGS. 12A and 12B or 13, at least a portion of the contour of the enlarged portions 73 and 83 of the first recesses 71 and 81 and at least a portion of the contour of the widened portions 75 and 85 of the first protrusions 72 and 82 may have a linear shape in side view or plan view. In the example shown in FIGS. 12A and 12B or 13, only a portion of the contour of the enlarged portions 73 and 83 of the first recesses 71 and 81 has a linear shape in side view or plan view. Therefore, the contour of the enlarged portions 73 and 83 of the first recesses 71 and 81 has a shape that combines a circular arc shape and a linear shape in side view or plan view. Similarly, only a portion of the contour of the widened portions 75 and 85 of the first protrusions 72 and 82 has a linear shape in side view or plan view. Therefore, the outline of the widened portions 75, 85 of the first convex portions 72, 82 has a shape that combines an arc shape and a linear shape in side view or plan view. Note that the entire outline of the narrowed portions 74, 84 of the first concave portions 71, 81 and the entire outline of the narrowed portions 76, 86 of the first convex portions 72, 82 each have an arc shape in side view or plan view.

[0083] Here, a portion of the outline of each of the first recesses 71 and 81 and a portion of the outline of each of the first protrusions 72 and 82 have an arc shape in a side view or a plan view. In this case, the central angle of the arc shape may be 190° or more and 280° or less, for example, 237°.

[0084] 14A and 14B, or 15, the entire contour of the enlarged portions 73, 83 of the first recesses 71, 81 may have a linear shape in side view or plan view. Similarly, the entire contour of the enlarged portions 75, 85 of the first protrusions 72, 82 may have a linear shape in side view or plan view. In this case, too, a portion of the contour of the first recesses 71, 81 and a portion of the contour of the first protrusions 72, 82 have an arc shape in side view or plan view. In this case, the central angle of the arc shape may be 150° or more and 180° or less, for example, 180°.

[0085] In this modification, deformation of the side portion 23 can be suppressed, and contact of surrounding structures and the like from the outside with the molded film 40 can be suppressed. In addition, formation of a gap G between the first flange piece 25a and the second flange piece 25b can be suppressed.

[0086] (Second Modification) In the above-described embodiment, the first recesses 71, 81 include enlarged portions 73, 83 and reduced portions 74, 84, and the first protrusions 72, 82 include widened portions 75, 85 and narrowed portions 76, 86. However, this is not limiting. For example, as shown in FIGS. 16A and 16B or 17, the first recesses 71, 81 and the first protrusions 72, 82 may each be semicircular in side or plan view. In this modification, when the first protrusion 72 is accommodated in the first recess 71, interference between the first protrusion 72 and the portion of the first side portion 23a surrounding the first recess 71 can be more effectively prevented, making it easier to accommodate the first protrusion 72 in the first recess 71. Furthermore, this modification also prevents deformation of the side portion 23 and prevents surrounding structures and the like from coming into contact with the molded film 40 from the outside.

[0087] (Third Modification) In the above-described embodiment, an example has been described in which the first recess 71 and the first protrusion 72 are each formed approximately in the center of the side edge 23c of the side portion 23, and the first recess 81 and the first protrusion 82 are each formed approximately in the center of the side edge 33c of the side panel 33. However, this is not limiting. For example, as shown in Figures 18A and 18B or 19, the first recess 71 and the first protrusion 72 may each be formed closer to the first fold line 22 than the center of the side edge 23c of the side portion 23, and the first recess 81 and the first protrusion 82 may each be formed closer to the first fold line 32 than the center of the side edge 33c of the side panel 33.

[0088] 20A and 20B, or 21, the first recess 71 and the first protrusion 72 may be formed closer to the second fold line 24 than the center of the side edge 23c of the side portion 23, and the first recess 81 and the first protrusion 82 may be formed closer to the second fold line 34 than the center of the side edge 33c of the side panel 33. In the example shown in FIGS. 20A and 20B, or 21, the first recess 71 and the first protrusion 72 can be positioned closer to the flange pieces 25, thereby more effectively suppressing relative movement between the flange pieces 25. This more effectively suppresses relative movement between the first flange piece 25a and the second flange piece 25b, and more effectively suppresses the formation of a gap G between the first flange piece 25a and the second flange piece 25b.

[0089] In the illustrated example, the contours of the first recesses 71, 81 each have a shape that combines an arc shape and a linear shape in a side view or a plan view, and the contours of the first protrusions 72, 82 each have a shape that combines an arc shape and a linear shape in a side view or a plan view. Only a portion of the contours of the enlarged portions 73, 83 of the first recesses 71, 81 has a linear shape in a side view or a plan view, and only a portion of the contours of the widened portions 75, 85 of the first protrusions 72, 82 has a linear shape in a side view or a plan view. In this case, the central angle of the arc shape may be 190° or more and 280° or less, for example, 237°. 14A and 14B or 15, the entire contour of the enlarged portions 73, 83 of the first recesses 71, 81 may have a linear shape in side view or plan view, and the entire contour of the widened portions 75, 85 of the first protrusions 72, 82 may have a linear shape in side view or plan view. In this case, the central angle of the arc shape may be 150° or more and 180° or less, for example, 180°.

[0090] Furthermore, for example, although not shown, the contours of the enlarged portions 73, 83 and the reduced portions 74, 84 of the first recessed portions 71, 81 may each have an arc shape in side view or plan view, and the contours of the widened portions 75, 85 and the reduced portions 76, 86 of the first protrusions 72, 82 may each have an arc shape in side view or plan view. Furthermore, although not shown, the first recessed portions 71, 81 and the first protrusions 72, 82 may each be formed in a semicircular shape in side view or plan view.

[0091] (Fourth Modification) In the above-described embodiment, an example has been described in which a first recess 71 is formed in one side portion 23 (first side portion 23a), and a first protrusion 72 that is housed in the first recess 71 is formed in another side portion 23 (second side portion 23b) adjacent to the one side portion 23. Also, an example has been described in which a first recess 81 is formed in one side panel 33 (first side panel 33a), and a first protrusion 82 that is housed in the first recess 81 is formed in another side panel 33 (second side panel 33b) that faces the one side panel 33 across a gap 36. In this case, as shown in FIGS. 22A and 22B , a second recess 710 may be formed in the other side portion 23 (second side portion 23b), and a second protrusion 720 that is housed in the second recess 710 may be formed in the one side portion 23 (first side portion 23a). Also, as shown in Figure 23, a second recess 810 may be formed in the other side panel 33 (second side panel 33b), and a second protrusion 820 that is accommodated in the second recess 810 may be formed in one side panel 33 (first side panel 33a).

[0092] 22A and 22B, or 23, the contours of the enlarged portions 73, 83 and the reduced portions 74, 84 of the first recessed portions 71, 81 and the contours of the widened portions 75, 85 and the narrowed portions 76, 86 of the first protrusions 72, 82 each have an arc shape in side view or plan view. However, this is not limited thereto, and as shown in FIGS. 24A and 24B, or 25, the contours of the enlarged portions 73, 83 of the first recessed portions 71, 81 and the contours of the widened portions 75, 85 of the first protrusions 72, 82 may each have a linear shape in side view or plan view. That is, the contours of the first recessed portions 71, 81 may each have a shape that combines an arc shape and a linear shape in side view or plan view, and the contours of the first protrusions 72, 82 may each have a shape that combines an arc shape and a linear shape in side view or plan view.

[0093] 24A and 24B or 25, similarly to the example shown in Figures 12A and 12B or 13, only part of the outline of the enlarged portions 73, 83 of the first recesses 71, 81 has a linear shape in side view or plan view, and only part of the outline of the widened portions 75, 85 of the first protrusions 72, 82 has a linear shape in side view or plan view. In this case, the central angle of the arc shape may be 190° or more and 280° or less, for example, 237°.

[0094] 26A and 26B or 27, similar to the example shown in Figures 14A and 14B or 15, the entire contour of the enlarged portions 73, 83 of the first recesses 71, 81 may have a linear shape in side view or plan view, and the entire contour of the widened portions 75, 85 of the first protrusions 72, 82 may have a linear shape in side view or plan view. In this case, the central angle of the arc shape may be 150° or more and 180° or less, for example, 180°.

[0095] Furthermore, as shown in FIGS. 28A and 28B, or FIG. 29, the first recesses 71, 81 and the first protrusions 72, 82 may each be formed in a semicircular shape in a side view or a plan view.

[0096] 22A to 29, the shapes of the second recesses 710, 810 are point-symmetric to the shapes of the first recesses 71, 81. Similarly, the shapes of the second convex portions 720, 820 are point-symmetric to the shapes of the first convex portions 72, 82. However, this is not limiting, and the shapes of the second recesses 710, 810 do not have to be point-symmetric to the shapes of the first recesses 71, 81, and the shapes of the second convex portions 720, 820 do not have to be point-symmetric to the shapes of the first convex portions 72, 82.

[0097] In this modification, a second recess 710 (second recess 810) is formed in the second side portion 23b (second side panel 33b), and a second protrusion 720 (second protrusion 820) is formed in the first side portion 23a (first side panel 33a). This more effectively prevents deformation of the side portion 23 and more effectively prevents surrounding structures and the like from coming into contact with the molded film 40 from the outside. [Example]

[0098] Next, a specific example of the above embodiment will be described.

[0099] Example 1 (1) Formability evaluation First, the formability of the paper container 20 was evaluated. At this time, a blank material 30 shown in FIG. 5 was first produced. In this case, a paper container having a basis weight of 260 g / m 2 , 350g / m 2 Two types of coated paper were prepared. Each paper material was punched into a predetermined shape to produce a blank material 30.

[0100] Next, the obtained blank material 30 was attached to the cavity-side mold 60 and assembled to produce two types of paper containers 20. Then, the moldability of each of the assembled paper containers 20 was evaluated.

[0101] (2) Strength measurement test Next, a strength measurement test was carried out. First, a film (thickness: 120 μm) having the following layer structure was prepared as the formed film 40. PE(40μm) / Ionomer(40μm) / PE(40μm) Next, a film was laminated on the surface of each paper container 20 to produce two types of paper containers 10.

[0102] Next, the strength of each paper container 10 was measured. As shown in FIG. 30 , the paper container 10 was fixed with a fixing jig 91 with the forming film 40 facing downward so that the flange piece 25 would not move. Next, a cylindrical pressure jig 92 with a diameter of 10 mm was used to apply pressure to the bottom 21 of the paper container 10 near the boundary between the first side portion 23a and the second side portion 23b. The pressure was applied to the bottom 21 by the pressure jig 92 until at least one of the first side portion 23a and the second side portion 23b was crushed. The pressure rate was 50 mm / min. The maximum load applied by the pressure jig 92 to the paper container 10 was then measured.

[0103] (3) Sealing evaluation test Next, a sealability evaluation test was carried out. First, each paper container 10 was filled with a test liquid (Ageless Seal Check (product name) manufactured by Mitsubishi Gas Chemical Company).

[0104] A laminated film was also prepared as the lid material 50. In this case, a polyethylene terephthalate film with a transparent vapor deposition layer (manufactured by DNP Technopack Co., Ltd., IB-PET-UB, thickness 12 μm), a nylon film (thickness 15 μm), and a polyethylene film (thickness 40 μm) were laminated by dry lamination to produce the laminated film.

[0105] Then, each paper container 10 was sealed with the laminated film to produce two types of paper containers 1 with lids.

[0106] The resulting paper containers 1 with lids were then stored for one day with the lids 50 facing downwards, and each paper container 1 with lids was then checked to see if any liquid had leaked.

[0107] Example 2 A moldability evaluation, strength measurement test, and sealing performance evaluation test were performed in the same manner as in Example 1, except that the blank 30 shown in Fig. 13 was produced. In this case, the width of the base end 82a was 6.0 mm, and the width of the widest part of the reduced width portion 86 was 9.2 mm. In addition, the central angle of the arc shape of the outline of the first recess 81 was 237°.

[0108] Example 3 A formability evaluation, strength measurement test, and sealing property evaluation test were performed in the same manner as in Example 1, except that the blank 30 shown in Fig. 15 was produced. In this case, the width of the base end 82a was 8.0 mm, and the width of the widest part of the reduced width portion 86 was 10.7 mm. In addition, the central angle of the arc shape of the outline of the first recess 81 was 180°.

[0109] Example 4 A formability evaluation, strength measurement test, and sealing property evaluation test were carried out in the same manner as in Example 1, except that a blank material 30 shown in FIG. 17 was produced.

[0110] Example 5 The blank material 30 shown in FIG. 19 was produced, and in a strength measurement test, the basis weight was 260 g / m 2 The moldability evaluation, strength measurement test, and sealability evaluation test were performed in the same manner as in Example 1, except that the strength of only the paper container 10 using the coated paper was measured. In this case, the width of the base end 82a was 6.0 mm, and the width of the widest part of the reduced width portion 86 was 9.2 mm. In addition, the central angle of the arc shape of the outline of the first recess 81 was 237°.

[0111] Example 6 The blank material 30 shown in FIG. 21 was produced, and in a strength measurement test, the basis weight was 260 g / m 2 The moldability evaluation, strength measurement test, and sealability evaluation test were performed in the same manner as in Example 1, except that the strength of only the paper container 10 using the coated paper was measured. In this case, the width of the base end 82a was 6.0 mm, and the width of the widest part of the reduced width portion 86 was 9.2 mm. In addition, the central angle of the arc shape of the outline of the first recess 81 was 237°.

[0112] Example 7 The blank material 30 shown in FIG. 23 was produced, and in a strength measurement test, the basis weight was 260 g / m 2 The moldability evaluation, strength measurement test, and sealability evaluation test were carried out in the same manner as in Example 1, except that the strength of only the paper container 10 using the coated paper was measured.

[0113] Example 8 The blank material 30 shown in FIG. 25 was produced, and in a strength measurement test, the basis weight was 260 g / m 2 The moldability evaluation, strength measurement test, and sealability evaluation test were performed in the same manner as in Example 1, except that the strength of only the paper container 10 using the coated paper was measured. In this case, the width of the base end 82a was 6.0 mm, and the width of the widest part of the reduced width portion 86 was 9.2 mm. In addition, the central angle of the arc shape of the outline of the first recess 81 was 237°.

[0114] Example 9 The blank material 30 shown in FIG. 27 was produced, and in a strength measurement test, the basis weight was 260 g / m 2 The moldability evaluation, strength measurement test, and sealability evaluation test were performed in the same manner as in Example 1, except that the strength of only the paper container 10 using the coated paper was measured. In this case, the width of the base end 82a was 8.0 mm, and the width of the widest part of the reduced width portion 86 was 10.7 mm. In addition, the central angle of the arc shape of the outline of the first recess 81 was 180°.

[0115] Example 10 The blank material 30 shown in FIG. 29 was produced, and in a strength measurement test, the basis weight was 260 g / m 2 The moldability evaluation, strength measurement test, and sealability evaluation test were carried out in the same manner as in Example 1, except that the strength of only the paper container 10 using the coated paper was measured.

[0116] (Comparative Example 1) As shown in Figure 31, a blank material 30A was produced having side panels 33 (first side panel 33a, second side panel 33b) that did not have the first recess 81, first protrusion 82, second recess 810, and second protrusion 820 formed therein. Except for this, formability evaluation, strength measurement test, and sealing evaluation test were performed in the same manner as in Example 1.

[0117] The results are shown in Table 1.

[0118] [Table 1]

[0119] In the moldability evaluation column of Table 1 above, "◎" means that the first convex portion 72 firmly engaged with the first concave portion 71, so that no gap G was formed between the first flange piece 25a and the second flange piece 25b, even when the paper container 20 was removed from the cavity-side mold 60. Also, "◯" means that when the paper container 20 was removed from the cavity-side mold 60, a gap G was formed between the first flange piece 25a and the second flange piece 25b, but when the paper container 20 was attached to the cavity-side mold 60, no gap G was formed between the first flange piece 25a and the second flange piece 25b. Furthermore, "△" means that even when the blank material 30A was attached to the cavity side mold 60, the first flange piece panel 35a and the second flange piece panel 35b of the blank material 30A moved away from each other, and a gap was formed between the first flange piece panel 35a and the second flange piece panel 35b, extending from the outer edge to the inner edge of the first flange piece panel 35a (second flange piece panel 35b).

[0120] In the sealing property evaluation test column in Table 1 above, "○" means that no liquid leakage occurred in the lidded paper container 1. Furthermore, "△" means that no liquid leakage occurred in the lidded paper container when the lidded paper container was simply inverted so that the lid was facing downwards, but that liquid leakage occurred in the lidded paper container after it was then stored for one day with the lid facing downwards.

[0121] As a result, as shown in Table 1, in the formability evaluation, of the paper containers 20 according to Examples 1 to 3 and Examples 6 to 9, and the paper container 20 according to Example 5, those with a basis weight of 350 g / m 2In the paper container 20 using the coated paper, it was possible to prevent the formation of a gap G between the first flange piece 25a and the second flange piece 25b. In particular, in the paper container 20 according to Examples 6 to 9, even when the paper container 20 was removed from the cavity-side mold 60, the shape of the paper container 20 could be maintained, and it was possible to prevent the formation of a gap G between the first flange piece 25a and the second flange piece 25b. Therefore, it was found that the paper container 20 according to this embodiment could improve the airtightness of the paper container 1 with a lid.

[0122] Furthermore, as shown in Table 1, in the strength measurement test, the paper containers according to the comparative example had a basis weight of 260 g / m 2 In the paper container using the coated paper of the above formula, the maximum load applied until at least one of the first side portion 23a and the second side portion 23b was crushed was 18.4 N. In addition, among the paper containers according to the comparative example, the paper containers using the coated paper of the above formula, the maximum load applied until at least one of the first side portion 23a and the second side portion 23b was crushed was 18.4 N. 2 In the paper container using the coated paper, the maximum load applied until at least one of the first side portion 23a and the second side portion 23b was crushed was 34.3 N.

[0123] In contrast, among the paper containers 10 according to Examples 1 to 10, the basis weight is 260 g / m 2 In the paper container 10 using the coated paper, the maximum load applied until at least one of the first side portion 23a and the second side portion 23b was crushed was 20 N or more. 2 In the paper container 10 using the coated paper of Example 5, the maximum load applied until at least one of the first side portion 23a and the second side portion 23b was crushed was 38 N or more. This shows that the strength of the paper container 10 according to this embodiment can be improved. Among the paper containers 10 according to Examples 5 to 10, the paper containers 10 having a basis weight of 350 g / m 2 Although no strength measurement tests were conducted on the paper container 10 using the coated paper, the first side portion 23a and the second side portion 23b were not crushed even when the paper container 10 was pressed with a finger.

[0124] Furthermore, as shown in Table 1, in the paper containers with lids 1 according to Examples 1 to 3 and Examples 6 to 10, the paper containers with lids 1 could be sealed, and no liquid leakage occurred in the paper containers with lids 1. Therefore, it was found that the paper containers with lids 1 according to the present embodiment can improve sealing properties.

[0125] The present disclosure is not limited to the above-described embodiments and modifications, and the components can be modified and embodied in practice without departing from the spirit of the present disclosure. Furthermore, various inventions can be created by appropriately combining multiple components disclosed in the above-described embodiments and modifications. Some components may be omitted from all the components shown in the embodiments and modifications. [Explanation of symbols]

[0126] 1 Paper container with lid 10 Paper containers 20 Paper containers 21 Bottom 22 First broken line 23 Side 23a First side 23b Second side 24 Second broken line 25 flange piece 30 blank material 31 Bottom Panel 32 First broken line 33 Side Panel 33a First side panel 33b Second side panel 34 Second broken line 35 flange panel 40 Forming Film 50 Lid material 71 First recess 72 First convex part 72b tip 75 Widened section 76 Reduced width section 710 Second recess 720 Second convex part 81 First recess 82 First convex part 82b tip 85 Widened section 86 Reduced width section 810 Second recess 820 Second convex part

Claims

1. A bottom panel; a plurality of side panels connected to the bottom panel via first fold lines; a plurality of flange piece panels connected to each of the side panels via second fold lines, A gap is formed between the side panels, A first recess is formed in one side panel; a first protrusion to be received in the first recess is formed on another side panel facing the one side panel with the gap therebetween; a second recess formed in the other side panel; The blank, wherein the one side panel is formed with a second protrusion that is received within the second recess.

2. The blank of claim 1 , wherein the first protrusion engages the first recess.

3. The blank material according to claim 1 or 2, wherein the first convex portion includes at least a widening portion whose width gradually increases from a base end side toward a tip end side.

4. The blank material according to claim 1 , wherein at least a portion of the contour of the first protrusion has an arc shape in a plan view.

5. A paper container produced by assembling the blank material according to any one of claims 1 to 4; A paper container comprising a formed film laminated on the surface of the paper container.

6. A paper container having a bottom, a plurality of side portions connected to the bottom via a first fold line, and a plurality of flange pieces connected to each of the side portions via a second fold line; A formed film laminated on a surface of the paper container, The side portions are adjacent to each other and are not continuous with each other, A first recess is formed in one side, a first protrusion to be received in the first recess is formed on another side portion adjacent to the one side portion, A second recess is formed in the other side portion, A paper container, the one side portion having a second protrusion formed thereon, the second protrusion being accommodated in the second recess.

7. The paper container according to claim 6 , wherein the first protrusion engages with the first recess.

8. The paper container according to claim 6 or 7, wherein the first convex portion includes at least a widening portion whose width gradually increases from a base end side to a tip end side.

9. The paper container according to claim 6 , wherein at least a portion of the contour of the first protrusion has an arc shape in a side view.

10. The paper container according to any one of claims 5 to 9, A paper container with a lid, comprising a lid that seals the paper container.

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