Web corner type paper container

Abstract

To provide a web corner type paper container that is in a folded state at a time of food sales and distribution and is capable of being expanded and used as a food container when in use.SOLUTION: The web corner type paper container of a laminated body including a paper layer and a resin layer has such a configuration that a web corner portion is included in which a bottom plate formed with a third folding line, a front side plate and a rear side plate formed with a Y-shaped folding line and a linear second folding line, a left side plate, and a right side plate are connected to each other, each side plate is connected with triangular folded pieces on both sides, flaps formed with a first folding line are connected in the front and rear side panels and a left half upper plate and a right half upper plate are connected in the left side plate and right side plate, which are folded and engaged with each other to close an upper surface. Straight portions of the first folding line and the Y-shaped folding line, and the second and third folding lines are linearly arranged to make it possible to fold it flat and stand it up on a box.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a web corner type paper container formed by a laminate having a resin layer on the inner surface of a paper layer, and more specifically, to a web corner type paper container that can be folded flat and stood up into a box shape. [Background technology]

[0002] Conventionally, web corner type paper containers have been widely used to prevent leakage of food with oil or seasonings or food that releases juices, such as simmered food. The main reason for this is that web corner type paper containers are made of a single blank, and have a structure in which, for example, a rectangular bottom plate is provided in the center, the periphery is folded along the edges to make the side plates stand up, and the four corners are folded outward and bonded to the outer surfaces of the side plates, providing excellent leakage prevention effects.

[0003] Furthermore, in recent years, it has become known that web corner type paper containers can be used as paper containers for heating in a microwave oven by providing a top panel connected to the side panels, placing food for microwave cooking inside, and covering the top panel (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-83398 A Summary of the Invention [Problem to be solved by the invention]

[0005] The web corner type paper container is an excellent paper container that is effective in preventing liquid leakage. However, when such a paper container is attached to a pouch containing curry or the like and sealed and then sold, there is a problem that the web corner type paper container is bulky.

[0006] The present invention has been made to solve the above problems, and its object is to provide a web corner type paper container that is folded when food is sold or distributed, and that can be unfolded when in use to put food inside and used as a food container. [Means for solving the problem]

[0007] The present invention has been made to achieve the above-mentioned object, and the present invention described in claim 1 relates to a web corner type paper container formed of a laminate having a resin layer on the inner surface of a paper layer, in which a front side plate, a rear side plate, a left side plate, and a right side plate are connected to the top, bottom, left and right sides of a rectangular bottom plate via fold lines, and each of the side plates has a triangular fold-in piece connected to both sides via fold lines, and adjacent fold-in pieces are connected to each other via radial fold lines extending outward from the corners of the bottom plate to form a web corner portion. The front and rear side panels have flaps connected to their upper edges via fold lines, the left and right side panels have left and right half upper panels connected to their upper edges via fold lines, and the left and right half upper panels have engagement parts at their tips that engage with each other. The web corner parts are folded outward and attached to the outside of the side panels to form a box shape, and the left and right half upper panels are then folded inward to engage the engagement parts at their tips. a first straight fold line is formed on a flap connected to the upper sides of the front and rear panels, a Y-shaped fold line branching into three and a linear second fold line are formed on the front and rear panels, the Y-shaped fold line is formed of an oblique line portion extending from a branch point toward a corner of the bottom panel and a linear portion extending toward the flap, the second fold line is formed linearly between the branch point of the Y-shaped fold line and the bottom panel, and the front and rear panels face each other at the bottom panel. a third fold line is formed in a direction perpendicular to the fold line, the first fold line, the straight portion of the Y-shaped fold line, the second fold line, and the third fold line of the bottom plate are arranged in a straight line in a plan view when viewed from the bottom plate side, and the front plate, the rear plate, the bottom plate, and the flaps can be folded flat at the first fold line, the Y-shaped fold line, the second fold line, and the third fold line and can be stood up into a box shape.

[0008] The present invention described in claim 2 relates to a web corner type paper container formed of a laminate having a resin layer on the inner surface of a paper layer, in which a front panel, a rear panel, a left panel, and a right panel are connected to the top, bottom, left, and right sides of a rectangular bottom panel via fold lines, and each of these side panels has a triangular fold-in piece connected to both sides via fold lines, and adjacent fold-in pieces are connected to each other via radial fold lines extending outward from the corners of the bottom panel to form a web corner portion, and flaps are connected to the upper sides of the front panel and the rear panel via fold lines. A left half upper plate and a right half upper plate are respectively connected to the left side plate and the right side plate via fold lines on their upper sides, and engaging portions shaped to engage with each other are formed at the tips of the left half upper plate and the right half upper plate. Each web corner portion is folded outward and attached to the outside of the side plate to form a box shape, and then the left half upper plate and the right half upper plate are folded inward and the engaging portions formed at the tips are engaged with each other to close the top surface. A linear first fold line is formed on a flap connected to the upper sides of the front side plate and the rear side plate. a Y-shaped folding line branching into three, a linear second folding line, and a linear fourth folding line are formed on the front and rear panels, the Y-shaped folding line being formed of an oblique line portion extending from a branch point toward a corner of the bottom panel and a straight line portion extending toward the flap, the second folding line being formed linearly between the branch point of the Y-shaped folding line and the bottom panel, the fourth folding line being formed linearly between the branch point of the Y-shaped folding line and the fold piece on the adjacent right panel, and the bottom panel being formed of a third folding line in a direction in which the front and rear panels face each other. a fourth fold line is formed on the right side plate, the straight portion of the Y-shaped fold line, the second fold line, and the third fold line of the bottom plate are arranged in a straight line in a plan view when viewed from the bottom plate side, a fourth fold line is formed on the right side plate parallel to the third fold line, and a fourth fold line is formed on the folding piece adjacent between the right side plate and the front plate and between the right side plate and the rear plate, and when the portion of the bottom plate and the right side plate from the fourth fold line to the bottom plate is folded at the fourth fold line of the right side plate and overlapped with the right side plate,The fourth fold lines of the front panel and the rear panel and the fourth fold line of the fold-in piece are formed to be folded in synchronization with the folding operation of the fourth fold line of the right panel, and the front panel, the rear panel, the bottom panel and the flap can be folded flat at the first fold line, the Y-shaped fold line, the second fold line and the third fold line, and can be erected into a box shape.

[0009] The present invention described in claim 3 is characterized in that, in the web corner type paper container described in claim 1 or claim 2, the engaging portion has a bulge portion at the tips of the left half upper plate and the right half upper plate that bulges outward from one outer end to the center, and a notch is formed on the center side of the bulge portion, and the left half upper plate and the right half upper plate are folded inward, and the notches of the engaging portions formed at their tips engage with each other to close the top surface.

[0010] The present invention described in claim 4 is characterized in that, in the web corner type paper container described in claim 2, a protrusion is formed on the outer end side of the bulge opposite the cutout, and a slit is formed in the flap into which the protrusion is inserted. Effect of the Invention

[0011] The web corner type paper container of the present invention is in a folded state when food is sold or distributed, and when in use, it can be easily unfolded from the folded state and used as a food container. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view showing a web corner type paper container according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a development view of a blank for assembling the web corner type paper container of FIG. 1. [Diagram 3]FIG. 3 is an explanatory diagram showing an intermediate state in which a web corner type paper container is assembled from the blank of FIG. 2. [Figure 4] 4 is an explanatory diagram showing the web-corner type paper container in the intermediate assembly state of FIG. 3 folded along a first fold line. FIG. [Diagram 5] 5 is an explanatory diagram showing the web corner type paper container of FIG. 4 folded along the second fold line and the third fold line. FIG. [Figure 6] FIG. 2 is a cross-sectional view showing the layer structure of a laminate of blanks for a web-corner type paper container of the present invention. [Figure 7] FIG. 11 is a development view of a blank for assembling a web corner type paper container according to a second embodiment of the present invention. [Figure 8] FIG. 11 is an explanatory diagram showing a state in which a web corner type paper container according to a second embodiment of the present invention is folded along a fourth fold line. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention will be described in detail below with reference to the drawings.

[0014] FIG. 1 is a perspective view showing a web corner type paper container of a first embodiment of the present invention, FIG. 2 is a development view of a blank for assembling the web corner type paper container of FIG. 1, FIG. 3 is an explanatory diagram showing an intermediate state of assembling a web corner type paper container from the blank of FIG. 2, FIG. 4 is an explanatory diagram showing the web corner type paper container in the intermediate state of assembly of FIG. 3 folded along a first fold line, FIG. 5 is an explanatory diagram showing the web corner type paper container of FIG. 4 folded along a second fold line and a third fold line, FIG. 6 is a cross-sectional view showing the layer structure of a laminate of blanks for a web corner type paper container of the present invention, FIG. 7 is a development view of a blank for assembling a web corner type paper container of a second embodiment of the present invention, and FIG. 8 is a cross-sectional view showing the layer structure of a laminate of blanks for a web corner type paper container of the present invention. FIG. 1 is an explanatory diagram showing a web-corner type paper container folded at a fourth fold line, in which C is a web-corner type paper container, 1 is a bottom plate, 2 is a front plate, 2a, 3a, 4a, 5a are fold-in pieces, 2b, 3b are triangular portions, 3 is a rear plate, 4 is a left side plate, 5 is a right side plate, 6, 7 are flaps, 6a, 7a are slits, 8 is a left upper plate, 8a, 9a are bulges, and 8b, 9b are cutouts. , 8c, 9c are protruding portions, 8d, 9d are overlapping portions, 9 is the right upper plate, 10 is a Y-shaped folding line, 10a is a branching point, 10b is a diagonal line portion, 10c is a straight portion, 11 is a first folding line, 12 is a second folding line, 13 is a third folding line, 14 is a fourth folding line, 20, 20' are blanks, 21 is a paper layer, 22 is a resin layer, W is a web corner portion, and a, b, c are fold lines.

[0015] FIG. 1 is a perspective view showing a web corner type paper container of a first embodiment according to the present invention, and the web corner type paper container C is formed by assembling blanks 20 shown in a developed view in FIG.

[0016] The blank 20 shown in Fig. 2 is formed by punching out into a predetermined shape a laminate having a resin layer on the inner surface of a paper layer made of paperboard, with a front panel 2 and a rear panel 3 connected to the top and bottom edges (left and right in Fig. 2) of a rectangular bottom panel 1 via fold lines, and a left panel 4 and a right panel 5 connected to the left and right edges (top and bottom in Fig. 2) of the bottom panel 1 via fold lines, respectively. Triangular fold pieces 2a, 3a, 4a, 5a are connected to both sides of the front panel 2, rear panel 3, left panel 4, and right panel 5 via fold lines, respectively, and adjacent fold pieces are connected to each other via radial fold lines a extending outward from the corners of the bottom panel 1 to form a web corner portion W.

[0017] Flaps 6 and 7 are connected to the upper edges of the front panel 2 and the rear panel 3 via fold line b, and left half upper panel 8 and right half upper panel 9 are connected to the upper edges of the left panel 4 and the right panel 5 via fold line b, with engaging portions formed at the tips of the left half upper panel 8 and the right half upper panel 9 to engage with each other. In Fig. 2, the engaging portions are formed at the tips of the left half upper panel 8 and the right half upper panel 9 via fold line c with bulging portions 8a and 9a bulging outward, and the bulging portions 8a and 9a are horizontally long from one outer end to the center, approximately half the length of the left half upper panel 8 and the right half upper panel 9 in the left-right direction in Fig. 2, and have groove-shaped cutouts 8b and 9b on the center side of the bulging portions 8a and 9a, with protrusions 8c and 9c formed on the outer end side opposite the notches 8b and 9b. The bulging parts 8a, 9a are formed point symmetrically, and the groove-shaped notches 8b, 9b mesh with each other and engage with each other. The left half upper plate 8 and the right half upper plate 9 are folded inward, and the groove-shaped notches 8b, 9b are engaged with each other to close the upper surface. The engaging part is not limited to the structure shown in FIG. 2, as long as the left half upper plate 8 and the right half upper plate 9 mesh with each other. The bulging parts 8a, 9a, the notches 8b, 9b, and the protruding parts 8c, 9c are collectively called the engaging part. Also, the outer side as viewed from the center of the blank 20 may be called the upper side. In FIG. 2, the blank 20 is rotated 90° clockwise for convenience, and the up-down direction refers to the left and right in the drawing, and the left-right direction refers to the up-down direction in the drawing. Hereinafter, the up-down direction and the left-right direction will be referred to according to the drawing.

[0018] Flaps 6 and 7 are connected to the front panel 2 and the rear panel 3 via fold line b, and have slits 6a and 7a into which protrusions 8c and 9c are inserted. The slits 6a and 7a penetrate the blank 20 in the left-right direction, and the slits 6a and 7a are surrounded by an ellipse with a cut having a ratchet stop, and the slits 6a and 7a are located on the major axis of the ellipse surrounded by the cut on the outer periphery.

[0019] In the web corner type paper container C of the first embodiment, a straight first fold line 11 is formed on the flaps 6, 7 connected to the upper edges of the front panel 2 and the rear panel 3, a Y-shaped fold line 10 branching into three and a linear second fold line 12 are formed on the front panel 2 and the rear panel 3, the Y-shaped fold line 10 is formed by a diagonal portion 10b extending from the branch point 10a toward the corner of the bottom panel 1 and a straight portion 10c extending toward the flaps 6, 7, the second fold line 12 is formed in a straight line between the branch point 10a of the Y-shaped fold line 10 and the bottom panel 1, and a third fold line 13 is formed on the bottom panel 1 in the left-right direction where the front panel 2 and the rear panel 3 face each other.

[0020] The first folding lines 11 formed on the flaps 6 and 7, the straight line portion 10c of the Y-shaped folding line 10 formed on the front panel 2 and the rear panel 3, and the second folding line 12 and the third folding line 13 formed on the bottom panel 1 are arranged so as to be located on an imaginary straight line that crosses the centers of the flap 6, the front panel 2, the bottom panel 1, the rear panel 3, and the flap 7. When assembled into a paper container, these folding lines are arranged linearly in a plan view when viewed from the bottom panel 1 side. With this configuration, as will be described later, the web corner type paper container C can be folded flat at the first folding line 11, the Y-shaped folding line 10, the second folding line 12, and the third folding line 13, and is not bulky and can be erected into a box shape.

[0021] Of the fold lines shown by dotted lines in FIG. 2, for example, fold line a is a pressed crease, fold line b shown by dashed lines is preferably formed by perforations, and fold line c shown by dashed dotted lines is preferably a lead crease consisting of a pressed crease and a cut.

[0022] Next, a method of assembling the blank 20 will be described with reference to Figures 2 and 3. The front panel 2, rear panel 3, left panel 4, and right panel 5 are folded upright at the fold lines relative to the bottom panel 1, and the folded pieces 2a, 3a, 4a, and 5a are pulled outward and folded in along the fold line a to form a web corner W. With each web corner W folded outward, the outside of the folded piece 4a is placed on the outside of the left panel 4, and the outside of the folded piece 5a is placed on the outside of the right panel 5, and these are then glued together to form a box shape as shown in Figure 3. Each side panel of the box shape is an isosceles trapezoid with the upper base longer than the lower base, so a box is formed that has a taper that widens upward.

[0023] Next, a method of folding a box shape having a taper that expands upward as shown in Fig. 3 will be described. First, as shown in Fig. 4, with the top open, the flap 6 and the front panel 2, and the flap 7 and the rear panel 3 are pulled outward while the first folding line 11 and the straight line portion 10c of the Y-shaped folding line 10 are mountain-folded outward to the branch point 10a. In sync with this operation, the oblique line portion 10b is mountain-folded to form ridges from the branch point 10a to the corners of the bottom panel 1. Fig. 4 shows this state, as seen from the bottom panel 1 side. This operation forms two quadrilateral portions and a triangular portion in the front panel 2 and the rear panel 3, forming a three-dimensional shape centered on the branch point 10a.

[0024] Next, the center of the ridge of the bottom plate 1 to which the front plate 2 is connected and the center of the ridge of the bottom plate 1 to which the rear plate 3 is connected are pressed inward, and the second folding line 12 and the third folding line 13 are folded inward to form a valley. The triangular portions 2b, 3b formed on the bottom plate 1, the front plate 2, and the rear plate 3 are folded in half, so that their outer surfaces face each other. Figure 5(a) is a side view showing this state, and Figure 5(b) is a bottom view. As shown in Figure 5(a), when viewed from the side, the folded state resembles the shape of a sailboat, and it can be folded flat. This makes it less bulky. The bottom view of Figure 5(b) shows the state in which the triangular portions 2b, 3b formed on the bottom plate 1, front plate 2 and rear plate 3 are folded in half along the second fold line 12 formed on the triangular portion 2b of the front plate 2, the third fold line 13 on the bottom plate 1 and the second fold line 12 formed on the triangular portion 3b of the rear plate 3, with their outer surfaces facing and close to each other.

[0025] When using the folded web corner type paper container shown in Fig. 5, the triangular portions 2b, 3b formed on the bottom panel 1, front panel 2, and rear panel 3 that are folded in half are spread outward while the straight portions 10c of the front panel 2 and rear panel 3 are pushed inward, so that the left and right sides of the bottom panel 1 that contact the front panel 2 and rear panel 3 are pushed outward, and the rectangular bottom panel 1 and the trapezoidal front panel 2 and rear panel 3 are spread out and restored to their original state, resulting in a web corner type paper container with an open top as shown in Fig. 3. By using paperboard for the paper layer 21 (see Fig. 6) of the blank 20 of the web corner type paper container C, the rigidity of the laminate is obtained, making it easy to restore the box shape.

[0026] Next, a method of using the web corner type paper container C will be described with reference to Figures 3 and 1. Contents are placed into the web corner type paper container C shown in Figure 3, the left half upper plate 8 and the right half upper plate 9 are folded inward, and the bulges 8a and 9a formed at the respective tips of the left half upper plate 8 and the right half upper plate 9 are valley folded along the fold line c and raised, with the notches 8b and 9b interlocking with each other. At this time, the upper edge portion of the left upper plate 8, which is located on the opposite side of the bulge 8a from the cutout 8b, becomes an overlapping portion 8d in a state where it is extended slightly outward due to the formation of the cutout 8b, and this extended overlapping portion 8d slips into the inside of the right upper plate 9 and is overlapped therewith; similarly, the upper edge portion of the right upper plate 9, which is located on the opposite side of the bulge 9a from the cutout 9b, becomes an overlapping portion 9d in a state where it is extended slightly outward due to the formation of the cutout 9b, and this extended overlapping portion 9d slips into the inside of the left upper plate 8 and is overlapped therewith; by engaging the notches 8b, 9b together, the top of the box is closed and the lid is placed.

[0027] Next, the flaps 6, 7 are folded inward, and the protruding portion 9c is inserted into the slit 6a, and the protruding portion 8c is inserted into the slit 7a, thereby reliably fixing the lid whose top surface is closed by the left half upper plate 8 and the right half upper plate 9. Furthermore, the upright bulges 8a, 9a serve as handles, so that when the contents contained in the web corner type paper container C are to be cooked in a microwave oven, the container has a form suitable for use in a microwave oven, allowing the contents to be safely removed from the oven. The structure in which the protruding portions 8c, 9c are provided on the bulging portions 8a, 9a, and the slits 6a, 7a are provided on the flaps 6, 7 are not essential, but the lid can be reliably fixed by inserting the protruding portions 9c, 8c into the slits 6a, 7a, and the bulging portions 8a, 9a serve as handles when removing the container from the microwave oven, so this is a preferred embodiment. When the slits 6a, 7a are not provided, the flaps 6, 7 may be first folded inward so as to overlap with the inner surfaces of the left half upper plate 8 and the right half upper plate 9.

[0028] In this way, the web corner type paper container C can be folded flat, does not become bulky, and can be easily assembled when used. Furthermore, after the assembled web corner type paper container C is filled with contents and cooked in a microwave oven, it can be used as a food container as is and eaten. After the contents are eaten, the paper container can be easily folded flat in the above-mentioned procedure and does not become bulky, so that waste can be reduced. The bulges 8a and 9a constituting the engagement portion protrude outward on the cutouts 8b and 9b sides, respectively, and the inner surfaces of the protruding parts of the bulges 8a and 9a on the cutouts 8b and 9b sides overlap each other, and when folded, it is preferable that the outer surfaces of the protruding parts of the bulges 8a and 9a overlap each other at the protruding parts, and engage with the cutouts 8b and 9b, which can further reduce the volume.

[0029] The web corner type paper container C, which can provide a variety of effects, can be folded to reduce its bulk and can be used as a microwaveable food container that can be attached to mail-ordered foods, such as pouched retort curry. In more detail, in recent years, the delivery services of shipping companies have become more diverse, and various types of transportation and delivery have been performed, such as Nekopos (registered trademark) provided by Yamato Transport Co., Ltd., which delivers small packages to mailboxes. For such delivery services, an upper limit is set for the size of Nekopos (registered trademark) so that the package can be delivered to a mailbox. The web corner type paper container C of the present invention can be folded to become flat, so that the height in the thickness direction can be reduced. For example, even if the web corner type paper container C is folded and attached to mail-ordered foods, it fits within the height limit, so it can be used for the Nekopos (registered trademark) delivery service.

[0030] The layer structure of the laminate constituting the blank 20 which achieves such an effect is shown in Fig. 6. The blank 20 is a laminate in which a resin layer 22 is laminated on the inner side of a paper layer 21. For the paper layer 21, a paperboard having a stiffness sufficient to stand up the folded web corner type paper container C is used. Coated cardboard, uncoated cardboard, kraft cardboard, manila cardboard, etc. can be used, and the basis weight is, for example, 220 g / m 2 More than 550g / m 2 Less than 350 g / m is preferable. 2 More than 450g / m 2 More preferably, the outer surface of the paper layer 21 may be plain, but is usually printed with a design, text, etc.

[0031] Resins such as polyethylene, polypropylene, polyethylene terephthalate, and polybutylene terephthalate are used for the resin layer 22, and these resins are laminated to the paper layer 21 by hot melt extrusion. Alternatively, these resins are made into a film and dry laminated to the inner surface of the paper layer 21 using a urethane adhesive or the like. The thickness of the resin layer 22 is usually 12 μm to 60 μm. The resin layer 22 may also be provided as a surface coating layer by coating the inner surface of the paper layer 21 with a resin composition that is oil-resistant, water-resistant, and heat-resistant. By providing the resin layer 22, it is possible to prevent leakage of liquid even if the contents are foods with oil, seasonings, etc. attached thereto, or foods that release juice such as simmered foods. Furthermore, by using resins such as polypropylene, polyethylene terephthalate, and polybutylene terephthalate, heat resistance is obtained, and the contents can be cooked in a microwave oven while still contained in the web corner type paper container C.

[0032] The web corner type paper container C in Fig. 1 can be folded flat so it is not bulky, and when in use it can be unfolded to contain the contents, which can be eaten as is or cooked in a microwave oven, making it particularly suitable as a web corner type paper container for mail order that is attached to food products for mail order.Furthermore, after use it can be folded and disposed of, which reduces the volume of waste.

[0033] FIG. 7 is a development view of a blank 20' for assembling a web corner type paper container of the second embodiment of the present invention. The web corner type paper container of the second embodiment is not shown, but has the same appearance as the web corner type paper container C of the first embodiment shown in FIG. 1, and is different in that it has a fourth fold line and a folded form, but otherwise is the same, so the same reference numerals are used and the description is omitted. As shown in FIG. 7, in the blank 20' for assembling the web corner type paper container of the second embodiment, a fourth fold line 14 is formed on the right side panel 5 in the direction in which the front panel 2 and the rear panel 3 face each other, and is parallel to the third fold line 13 of the bottom panel 1. The fourth fold line 14 is formed on the front panel 2 between the branch point 10a of the Y-shaped fold line 10 and the fold piece 2a adjacent to the front panel 2, and the fourth fold line 14 is formed on the rear panel 3 between the branch point 10a of the Y-shaped fold line 10 and the fold piece 3a adjacent to the rear panel 3. Fourth fold lines 14 are also formed in a straight line on adjacent fold pieces 2a, 5a between the right side panel 5 and the front panel 2, and on adjacent fold pieces 5a, 3a between the right side panel 5 and the rear panel 3. If imaginary extension lines of these fourth fold lines 14 are drawn, for example, the imaginary extension lines of the fourth fold line 14 of the front panel 2 and the fourth fold line 14 of the fold piece 2a intersect at the fold line shown by the dotted line that separates the front panel 2 and the fold piece 2a. Similarly, the imaginary extension lines of the respective fourth fold lines 14 intersect at the adjacent fold lines shown by the dotted lines.

[0034] The blank 20' can be assembled in the same manner as the blank 20 shown in Figures 2 and 3. The folding method is the same as that of the web corner type paper container C of the first embodiment, and as shown in Figures 4 and 5, when viewed from the side, the folded state is roughly the shape of a sailboat, and the paper container is folded flat. From this state, the web corner type paper container of the second embodiment can be further folded at the fourth fold line 14. Figure 8 is an explanatory diagram showing the web corner type paper container of the second embodiment of the present invention folded at the fourth fold line. Figure 8(a) shows the folded state as shown in Figure 5(a) in the flat state, and Figure 8(b) shows the folded state further at the fourth fold line 14. As shown in FIG. 8(A), when folded along the first fold line 11, the second fold line 12, and the third fold line 13, the fourth fold line 14 formed on the front panel 2, folding pieces 2a, 5a, right side panel 5, folding pieces 5a, 3a, and rear panel 3 are aligned in a straight line from side to side.

[0035] The straight line along which the fourth fold lines are aligned horizontally is located in the same position in a plan view as the second fold line 12 along which the triangular portion 2b of the front panel 2 and the triangular portion 3b of the rear panel 3 are folded, and the third fold line 13 along which the bottom panel 1 is folded. Since the fourth fold line 14 is located on an imaginary straight line formed by the first fold line 11, the second fold line 12, and the third fold line 13, the triangular portion 2b of the front panel 2, the bottom panel 1, the fold pieces 2a, 5a, the right panel 5, and the triangular portion 3b of the rear panel 3 on the side of the right panel 5 folded along the first fold line 11, the second fold line 12, and the third fold line 13 can be folded along the fourth fold line 14. That is, when the portions of bottom plate 1 and right side plate 5 from fourth fold line 14 to bottom plate 1 are folded at fourth fold line 14 of right side plate 5 and placed on right side plate 5, fourth fold line 14 of front plate 2 and rear plate 3 and fourth fold lines 14 of fold-out pieces 2a, 5a, 3a, 5a are folded in synchronization with the folding operation of fourth fold line 14 of right side plate 5, resulting in the folded state shown in Fig. 8(b). Also, when folded in the same manner as in the web corner type paper container C of the first embodiment, it is preferable that the outer surfaces of the protruding parts overlap each other and engage at the notches 8b, 9b.

[0036] It should be noted that the embodiments described so far are representative embodiments of the web corner type paper container of the present invention, and the web corner type paper container of the present invention is not limited to these, and also includes those that do not deviate from the spirit of the present invention. [Explanation of symbols]

[0037] C Web corner type paper container 1 Bottom plate 2 Front side panel 2a Fold-in piece 2b Triangular part 3 Rear plate 3a Fold-in piece 3b Triangle part 4 Left side board 4a Fold-in piece 5 Right side plate 5a Fold-in piece 6, 7 Flap 6a, 7a slit 8 Upper left half plate 8a, 9a bulge 8b, 9b cutout 8c, 9c protrusion 8d, 9d Polymerization part 9 Right upper plate 10 Y-shaped fold line 10a Junction 10b Shaded area 10c Straight section 11 First fold line 12 Second fold line 13 Third fold line 14 Fourth fold line 20, 20' Blank 21 Paper layer 22 Resin layer W Web Corner a, b, c fold lines

Claims

1. A web corner type paper container formed by a laminate having a resin layer on the inner surface of a paper layer, The front, rear, left and right panels are connected to the top, bottom and left sides of the rectangular bottom panel via fold lines, Each of the side panels has triangular fold pieces connected to both sides via fold lines, and adjacent fold pieces are connected to each other via radial fold lines extending outward from the corners of the bottom panel to form web corners. A flap is connected to each of the front and rear panels via a fold line at the upper edge thereof, A left half upper plate and a right half upper plate are respectively connected to the left side plate and the right side plate via fold lines on their upper edges, and an engagement portion is formed at the tip of the left half upper plate and the right half upper plate to be engaged with each other, Each web corner portion is folded outward and attached to the outside of the side plate to form a box shape, and then the left half upper plate and the right half upper plate are folded inward, and the engaging portions formed at the tips of the left half upper plate and the right half upper plate are engaged with each other to close the top surface. The engagement portion has a bulging portion at the tip of the left half upper plate and the right half upper plate, the bulging portion bulging outward from one outer end to the center, and a notch is formed on the center side of the bulging portion, The left half upper plate and the right half upper plate are bent inward, and the notches of the engagement portions formed at the tips of the left half upper plate and the right half upper plate are engaged with each other to close the upper surface, a protrusion is formed on an outer end side of the bulge portion opposite to the notch, and a slit is formed in the flap into which the protrusion is inserted, A flap connected to the upper sides of the front and rear panels has a first straight fold line formed thereon; The front and rear panels are formed with a Y-shaped folding line branching into three and a linear second folding line, the Y-shaped folding line being formed with an oblique line portion extending from a branch point toward a corner of the bottom panel and a linear portion extending toward the flap, and the second folding line being formed linearly between the branch point of the Y-shaped folding line and the bottom panel, A third folding line is formed on the bottom plate in a direction in which the front plate and the rear plate face each other, The first folding line, the straight portion of the Y-shaped folding line, the second folding line, and the third folding line of the bottom plate are arranged in a straight line in a plan view when viewed from the bottom plate side, A web corner type paper container, characterized in that the front panel, the rear panel, the bottom panel and the flaps can be folded flat along the first fold line, the Y-shaped fold line, the second fold line and the third fold line, and can be stood up into a box shape.

2. A web corner type paper container formed by a laminate having a resin layer on the inner surface of a paper layer, The front, rear, left and right panels are connected to the top, bottom and left sides of the rectangular bottom panel via fold lines, Each of the side panels has triangular fold pieces connected to both sides via fold lines, and adjacent fold pieces are connected to each other via radial fold lines extending outward from the corners of the bottom panel to form web corners. A flap is connected to each of the front and rear panels via a fold line at the upper edge thereof, A left half upper plate and a right half upper plate are respectively connected to the left side plate and the right side plate via fold lines on their upper sides, and an engagement portion is formed at the tip of the left half upper plate and the right half upper plate to be engaged with each other, Each web corner portion is folded outward and attached to the outside of the side plate to form a box shape, and then the left half upper plate and the right half upper plate are folded inward, and the engaging portions formed at the tips of the left half upper plate and the right half upper plate are engaged with each other to close the top surface. A flap connected to the upper sides of the front and rear panels has a first straight fold line formed thereon; The front and rear panels are formed with a Y-shaped folding line branching into three, a linear second folding line, and a linear fourth folding line, the Y-shaped folding line being formed with an oblique line portion extending from a branch point toward a corner of the bottom panel and a straight line portion extending toward the flap, the second folding line being formed linearly between the branch point of the Y-shaped folding line and the bottom panel, and the fourth folding line being formed linearly between the branch point of the Y-shaped folding line and the fold piece on the adjacent right panel, A third folding line is formed on the bottom plate in a direction in which the front plate and the rear plate face each other, The first folding line, the straight portion of the Y-shaped folding line, the second folding line, and the third folding line of the bottom plate are arranged in a straight line in a plan view when viewed from the bottom plate side, A fourth fold line parallel to the third fold line is formed on the right side plate, A fourth fold line is formed on the folding piece adjacent between the right side plate and the front side plate and between the right side plate and the rear side plate, When the bottom plate and the portion of the right side plate from the fourth fold line to the bottom plate are folded at the fourth fold line of the right side plate and overlapped with the right side plate, The fourth fold lines of the front and rear panels and the fourth fold line of the folding piece are formed to be folded in synchronization with the folding operation of the fourth fold line of the right side panel, A web corner type paper container, characterized in that the front panel, the rear panel, the bottom panel and the flaps can be folded flat along the first fold line, the Y-shaped fold line, the second fold line and the third fold line, and can be stood up into a box shape.

3. The engagement portion has a bulging portion at the tip of the left half upper plate and the right half upper plate, the bulging portion bulging outward from one outer end to the center, and a notch is formed on the center side of the bulging portion, The web corner type paper container according to claim 2, characterized in that the left half upper plate and the right half upper plate are folded inward, and the notches of the engaging portions formed at their tips engage with each other to close the top surface.

4. A web corner type paper container as described in claim 3, characterized in that a protrusion is formed on the outer end side of the bulge opposite the cutout, and a slit is formed in the flap into which the protrusion is inserted.

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