paper container

Abstract

To obtain a paper container into which an apex corner part of a shank formed by an apex lateral folding line is pushed with relatively little force, and to an inner side of which a midship part of the apex corner part can be easily folded.SOLUTION: A gable roof type paper container 1 pulls out a gable wall formation panel 24 on an opening side, which is folded between gable roof formation panels 16, 17 to open a bung hole. In the paper container, on a shank panel 8 on the opening side, which is provided continuously with a substantially triangular surface part 37 and the garble wall formation panel 24 that are surrounded by folding polygonal lines 34, 35 and an apex lateral folding line 26 in the garble wall formation panel 24, a first auxiliary folding line 48 straddling the apex lateral folding line 26 is positioned on a first virtual line L1 substantially orthogonal to the apex lateral folding line 26 at a substantially middle position of the apex lateral folding line 26 and is formed along the first virtual line L1, and on the shank panel 8, a second auxiliary line 58, which extends in a longitudinal direction from a lower end part of the first auxiliary folding line 48 or which is linear or is curved downward.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a paper container for accommodating liquid contents. [Background Art]

[0002] Conventionally, as a paper container for accommodating liquid contents such as milk and juice, it is made of a paperboard material with thermoplastic resin laminated on the front and back surfaces, includes four body panels, and edges are joined by a vertical seal panel to form a square cylindrical body. A pair of gable roof forming panels that have an outer top seal panel on the upper part and face each other are connected to the upper end of the body panels, and a pair of gable wall forming panels that have an inner top seal panel on the upper part, face each other, one of which serves as a spout and is unsealed are connected in series. A gable roof type paper container is widely used, in which the pair of gable wall forming panels are folded between the pair of gable roof forming panels, and the outer top seal panel and the inner top seal panel are heated, sealed and hermetically sealed at predetermined positions to form a top portion.

[0003] To open such a gable roof type paper container, a user inserts a finger into the space opened between the pair of gable roof forming panels, the body panel and the gable wall forming panel, hooks the finger on the gable wall forming panel and spreads it to the left and right, thereby peeling off the heat-sealed opposing surfaces of the outer top seal panel and the inner top seal panel on the unsealing side, then pulls out the gable wall forming panel folded between the pair of gable roof forming panels, and folds it outward from the top horizontal fold line at the boundary with the body panel continuously provided via the top horizontal fold line to open the spout. However, when the user's hand is large, the paper container is small, or the height of the gable roof type top is reduced for the purpose of space saving, the space formed between the body panel and the gable wall forming panel is narrow, which makes it difficult to hook a finger on the gable wall forming panel, resulting in the problem that the unsealing operation cannot be easily performed.

[0004] In recent years, a gable-roof type paper container has been known that solves these problems. This container features a gable-wall forming panel that is pulled out when the paper container is opened, and a body panel connected to the gable-wall forming panel. In this container, an auxiliary fold line is provided near the top horizontal fold line located at the boundary with the gable-wall forming panel, extending downward from one end of the top horizontal fold line to the other end of the body panel as it approaches the center (see, for example, Patent Document 1).

[0005] In a gable-roof type paper container with such auxiliary fold lines, when the top corner of the body formed by the top horizontal fold line is pushed inward into the container, the top corner folds inward along the auxiliary fold line, causing the upper part of the body panel sandwiched between the top horizontal fold line and the opening auxiliary crease to recess inward into the container. This widens the space for inserting fingers when placing them on the gable wall forming panel during opening, making it easier to open the paper container. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2002-234524 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] As described above, when opening the paper container described in Patent Document 1, the top corner of the body formed by the top horizontal fold line is pushed inward into the container, folding the top corner inward. However, the top corner has high bending strength to begin with, and since it is pushed from the convex side to the concave side, it is not easy to fold the top corner inward into the container. In particular, if the width of the body panel is short, it is difficult to push in, requiring a large force to push in the top corner, and there is a problem in that it is difficult to fold the top corner inward into the container.

[0008] The object of the present invention is to provide a paper container that is easy to open by allowing the top corner of the body formed by the top fold line to be pushed inward with relatively little force when opening, and the center of the top corner to be easily folded inward into the paper container, and furthermore, to provide a paper container that has functions that make it easy to use according to the application, such as when pouring liquid contents or drinking directly. [Means for solving the problem]

[0009] To achieve the above objective, the invention described in claim 1 is: In a gable-roof type paper container, the container is made of a cardboard material with thermoplastic resin laminated on its front and back surfaces, and comprises four body panels, the edges of which are joined by vertical sealing panels to form a square body, and at the upper end of the body panels, a pair of gable roof forming panels facing each other and having an outer top sealing panel on top, and a pair of gable wall forming panels facing each other and having an inner top sealing panel on top, with one of them serving as a spout for opening, are connected via a top horizontal fold line, the pair of gable wall forming panels are folded between the pair of gable roof forming panels by valley folding along a folding line, the top is formed when the outer top sealing panel and the inner top sealing panel are heated and sealed at a predetermined position, and at the lower end of the body panels, a bottom forming panel and an inner panel are connected via a bottom horizontal fold line, and the bottom is formed when the inner panel is folded inside the bottom forming panel. In the opening side of the end wall forming panel, the substantially triangular surface portion enclosed by the folding line and the top horizontal fold line, and in the opening side of the body panel connected to the end wall forming panel, a first auxiliary fold line that straddles the top horizontal fold line is located on a first imaginary line that is substantially perpendicular to the top horizontal fold line at approximately the center position of the top horizontal fold line, and is formed along this first imaginary line. Furthermore, the body panel has a second auxiliary fold line that is straight or curved downward, extending in the left-right direction from the lower end of the first auxiliary fold line, wherein the upper end of the substantially triangular face portion of the gable wall forming panel is located at or near the vertex of the substantially triangular face portion, and the lower end of the first auxiliary fold line on the body panel is located at a point at which the top horizontal fold line is at least 20% away from the top horizontal fold line by the height dimension connecting the vertex of the substantially triangular face portion of the gable wall forming panel and the top horizontal fold line. The second auxiliary fold line has its left and right ends positioned on a second imaginary line parallel to the top horizontal fold line, with the first auxiliary fold line in between. The left and right ends of the second auxiliary fold line are positioned on a third and fourth imaginary line connecting the vertex of the roughly triangular face of the gable wall forming panel, the ends of the left and right body vertical fold lines of the body panel, and the left and right ends of the bottom horizontal fold line. It is characterized by the following:

[0010] According to the invention described in claim 1, in the gable wall forming panel, the substantially triangular surface portion enclosed by the folding line and the top horizontal fold line, and the body panel connected to the gable wall forming panel, a first auxiliary fold line that straddles the top horizontal fold line is located on a first imaginary line substantially perpendicular to the top horizontal fold line at approximately the center position of the top horizontal fold line and is formed along this first imaginary line. Furthermore, in the body panel, a second auxiliary fold line is formed that is straight or downward curved and extends in the left-right direction from the lower end of the first auxiliary fold line. As a result, the bending strength of the portion at the top corner of the body formed by the top horizontal fold line where the top horizontal fold line and the first auxiliary fold line intersect is reduced. When the top corner is pressed in, the substantially triangular surface of the gable wall forming panel folds inward from the first auxiliary fold line, and the body panel is induced by the valley fold of the substantially triangular surface from the first auxiliary fold line to fold inward from the second auxiliary fold line. At the same time, it buckles and folds inward from an imaginary line connecting the intersection points of the left and right ends of the second auxiliary fold line, the left and right ends of the body vertical fold lines on the body panel, and the left and right ends of the top horizontal fold line, thereby inducing the central part of the top corner to fold inward into the paper container. As a result, the top corner can be pressed inward into the paper container with little force, and the substantially triangular surface of the gable wall forming panel and the upper part of the body panel can be recessed more easily and effectively.

[0011] If only the first auxiliary fold line becomes a valley fold and forms a concave shape, the lower end of the first auxiliary fold line on the body panel will become a convex shape that encloses the concave shape. However, since only the imaginary line connecting the lower end of the first auxiliary fold line, the ends of the left and right body vertical fold lines on the body panel, and the left and right ends of the top horizontal fold line is buckled, it acts as a damper but lacks reliability and is also weak against forces trying to return to its original shape. However, since a second auxiliary fold line is formed at the lower end of the first auxiliary fold line, the second auxiliary fold line folds in a mountain fold to divide the body panel into upper and lower sections in response to the force that tries to create a concave shape on the body panel by the first auxiliary fold line. This promotes buckling of the imaginary line connecting the end of the second auxiliary fold line, the ends of the left and right body vertical fold lines on the body panel, and the left and right ends of the top horizontal fold line, causing the lower end of the first auxiliary fold line to easily become a convex part.

[0012] Furthermore, since three continuous surfaces are formed on the same plane at a single point, indenting one common edge will cause the remaining sides to become convex. When the gable wall forming panel, which is folded between the pair of gable roof forming panels, is pulled out and the body panel is pushed in a way that indents it, the portion of the second auxiliary fold line will buckle and fold in a valley shape from the imaginary line connecting the intersection points of both ends of the second auxiliary fold line, the left and right ends of the second auxiliary fold line, the left and right ends of the body vertical fold lines, and the left and right ends of the top horizontal fold line. This is the reverse of the shape of the first auxiliary fold line indented when opened, with a V-shape paired on the left and right sides of the axis, and directly the This relates to the action of holding the body panel on the spout side, which has the first auxiliary fold line, and the body panel opposite it from the front and rear directions when drinking directly from the spout.

[0013] Furthermore, when pouring liquid contents from a square-shaped paper container, the spout side is held from both sides, so the first auxiliary crease, which is already creased upon opening, easily becomes a mountain fold, and the upper end of the body panel from the roughly triangular surface becomes a convex shape, making it easy to pour. Moreover, when drinking directly from the spout, the body panel opposite the spout side with the first auxiliary crease is held from the front and back, so the lower end of the first auxiliary crease on the body panel is recessed, effectively suppressing the return of the roughly triangular surface and the body panel that protrudes from the first auxiliary crease in the direction of the valley fold, thus maintaining the shape of the open spout and making it possible to create a paper container with a spout shape that is easy to drink directly from without being affected by the top horizontal crease. Furthermore, the first auxiliary fold line is positioned such that the upper end of the substantially triangular face portion of the gable wall forming panel is located at or near the vertex of the substantially triangular face portion of the gable wall forming panel, and the lower end of the first auxiliary fold line on the body panel is located at a distance of 20% or more from the top horizontal fold line that is equal to the height dimension connecting the vertex of the substantially triangular face portion of the gable wall forming panel and the top horizontal fold line. This allows the substantially triangular face portion of the gable wall forming panel and the body panel to be valley-folded from the first auxiliary fold line and the body panel to be mountain-folded from the second auxiliary fold line, thereby enabling the top corner to be pushed in with less force and folded inward into the paper container. Furthermore, if the lower end of the first auxiliary fold line on the body panel is located at a distance of 20% or more from the top horizontal fold line from the top horizontal fold line, then the area of ​​the triangular portion connecting the vertex of the approximately triangular face of the gable wall forming panel and the top horizontal fold line is secured at the top of the body panel, and the area of ​​the triangular portion connecting the end of the top horizontal fold line and the lower end of the first auxiliary fold line on the body panel is secured. By making a valley fold of the top horizontal fold line, a triangle can be created connecting the vertex of the approximately triangular face, the end of the top horizontal fold line and the lower end of the first auxiliary fold line on the body panel. As a result, the pair of V-shapes created on the left and right sides with the first auxiliary fold line as the axis become more stable and their concave state It becomes easier to maintain. Further, by bending the top corner portion and recessing the substantially triangular surface portion of the gable wall forming panel and the upper portion of the body panel, the space opened between the pair of gable roof forming panels, the body panel and the gable wall forming panel can be made a space sufficient for inserting a finger. Furthermore, since the left and right ends of the second auxiliary fold line are located on a second imaginary line parallel to the top horizontal fold line, the force applied when the top corner is pressed is evenly distributed to the left and right ends of the second auxiliary fold line. This allows the approximately triangular surface of the gable wall forming panel and the upper part of the body panel to be recessed more easily and effectively in a stable manner. Furthermore, by pulling out the gable wall forming panel that is folded between the pair of gable roof forming panels, the substantially triangular surface portion and the body panel that protrude from the first auxiliary fold line are more effectively prevented from returning in the valley fold direction, thereby maintaining the shape of the open spout in good condition. Furthermore, since the left and right ends of the second auxiliary fold line are located on third and fourth imaginary lines connecting the intersection points of the vertex of the roughly triangular face of the gable wall forming panel, the left and right ends of the body vertical fold lines of the body panel, and the left and right ends of the bottom horizontal fold line, when the top corner is pressed in, the body panel buckles and folds with less force from the imaginary lines connecting the left and right ends of the second auxiliary fold line, the left and right ends of the body vertical fold lines of the body panel, and the left and right ends of the top horizontal fold line, compared to when the left and right ends of the second auxiliary fold line are located outside the third and fourth imaginary lines. As a result, the roughly triangular face of the gable wall forming panel and the upper part of the body panel can be indented more easily.

[0018] Claim 2 , the invention according to 1 is characterized in that a lower end portion of the first auxiliary fold line is located at a position not more than 25% of a width dimension of the top transverse fold line from the top transverse fold line.

[0019] Claim 2 , according to the invention described in , since the lower end portion of the first auxiliary fold line in the body panel where the second auxiliary fold line is formed is located at a position not more than 25% of the width dimension of the top transverse fold line from the top transverse fold line, when the top corner portion is pushed in, the body panel does not bend in the middle of the first auxiliary fold line, and can reliably valley-fold up to the lower end portion of the first auxiliary fold line, thereby reliably inducing mountain-folding from the second auxiliary fold line. Effects of the Invention

[0024] As described above, according to the paper container of the present invention, it is possible to obtain a paper container in which, when opening the container, the top corner portion of the body formed by the top transverse fold line can be pushed into the inside of the container with a relatively small force, and the central portion of the top corner portion can be easily bent inward of the paper container. Brief Description of the Drawings

[0025] [Figure 1] It is a side view of the opening side showing an example of an embodiment of the paper container according to the present invention. [Figure 2] It is a plan view showing a carton blank of the paper container shown in FIG. 1. [Figure 3] It is a partially enlarged explanatory view of FIG. 2. [Figure 4] It is an explanatory diagram showing another example of the second auxiliary folding line of the paper container shown in Fig. 1. [Figure 5] It is an explanatory diagram showing another example of the second auxiliary folding line of the paper container shown in Fig. 1. [Figure 6] It is an explanatory diagram showing another example of the second auxiliary folding line of the paper container shown in Fig. 1. [Figure 7] It is an enlarged side explanatory view showing a state where the top corner of the paper container shown in Fig. 1 is pressed in. [Figure 8] It is an enlarged side explanatory view on the unsealing side showing a state where the gable wall forming panel of the paper container shown in Fig. 1 is pulled out in a direction away from the gable roof forming panel to open the spout. MODE FOR CARRYING OUT THE INVENTION

[0026] Hereinafter, modes for carrying out the paper container according to the present invention will be described in detail with reference to the drawings. Figs. 1 to 8 show an example of an embodiment of the paper container according to the present invention, wherein Fig. 1 is a side view of the paper container of the present example on the unsealing side, Fig. 2 is a plan view showing the carton blanks of the paper container shown in Fig. 1, Fig. 3 is a partially enlarged explanatory view of Fig. 2, Figs. 4 to 6 are each explanatory views showing another example of the second auxiliary folding line of the paper container shown in Fig. 1, Fig. 7 is an enlarged side explanatory view showing a state where the top corner of the paper container shown in Fig. 1 is pressed in, and Fig. 8 is an enlarged side explanatory view on the unsealing side showing a state where the gable wall forming panel of the paper container shown in Fig. 1 is pulled out in a direction away from the gable roof forming panel to open the spout.

[0027] The paper container 1 of the present example is formed from carton blanks 2, which is a paperboard material with thermoplastic resin laminated on the front and back surfaces shown in Fig. 2. The carton blanks include four body panels 6, 7, 8, 9 continuously provided via body longitudinal folding lines 3, 4, 5. When forming the paper container 1, the four body panels 6, 7, 8, 9 are joined at a longitudinal seal panel 11 continuously provided on the body panel 9 via a body longitudinal folding line 10 and an edge 12 of the body panel 6, so as to form a square cylindrical body 13 of the paper container.

[0028] At the upper ends of the body panels 7 and 9, a pair of gable roof forming panels 16 and 17, each having an outer top seal panel 14 and 15 at the top and facing each other, are connected via top horizontal fold lines 18 and 19. Additionally, at the upper ends of the body panels 6 and 8, a pair of gable wall forming panels 23 and 24, each having an inner top seal panel 20 and 21 at the top and facing each other, with one of them serving as a spout 22 for opening, are connected via top horizontal fold lines 25 and 26. In this example, gable wall forming panel 24 is the gable wall forming panel on the opening side.

[0029] The gable roof forming panels 16 and 17 have guide fold lines 27 and 28 formed on the side of the gable wall forming panel 24 on the opening side, which guides the folding of the gable roof forming panels 16 and 17 when opening. The gable roof forming panel 16 is also provided with a straw spout 31, which is formed by a first half-cut 29 that serves as a straw insertion opening formed on the back side and a second half-cut 30 that is formed on the front side to surround the first half-cut 29.

[0030] The gable wall forming panels 23 and 24 have folding lines 32, 33, 34, and 35 formed on them for folding. In addition, roughly triangular surfaces 36 and 37 are formed, enclosed by the folding lines 32, 33, 34, and 35 and the top horizontal folding lines 25 and 26.

[0031] During the formation of the paper container 1, the gable wall forming panels 23 and 24 are folded between the gable roof forming panels 16 and 17, and the outer top seal panels 14 and 15 and the inner top seal panels 20 and 21 are heated and sealed in predetermined positions to form a gable-shaped top 38 on the paper container 1.

[0032] Furthermore, bottom-forming panels 39 and 40 are connected to the lower ends of the body panels 6 and 8 via bottom horizontal fold lines 41 and 42, and inner panels 43 and 44 are connected to the lower ends of the body panels 7 and 9 via bottom horizontal fold lines 45 and 46, with the inner panels 43 and 44 folded inside the bottom-forming panels 39 and 40 to form the bottom 47.

[0033] Furthermore, in the gable wall forming panel 24 on the opening side, a roughly triangular surface portion 37 enclosed by the folding lines 34, 35 and the top horizontal fold line 26, and in the body panel 8 on the opening side connected to the gable wall forming panel 24, a first auxiliary fold line 48 that straddles the top horizontal fold line 26 is located on a first virtual line L1 that is approximately perpendicular to the top horizontal fold line 26 at approximately the center position of the top horizontal fold line 26 and is formed along this first virtual line L1. In the first example, the first auxiliary polyline 48 is a straight line, but it is not limited to this. For example, although not shown, it may be a dashed line or a wavy line.

[0034] In this example, the upper end portion 49 of the first auxiliary fold line 48 is located at or near the vertex 50 of the roughly triangular face portion 37. Furthermore, the position of the lower end portion 51 of the first auxiliary fold line 48 on the body panel 8 is not particularly limited, but it is preferable that it is located at a distance of 20% or more of the height dimension H connecting the vertex 50 of the roughly triangular face portion 37 and the top horizontal fold line 26 from the top horizontal fold line 26. Moreover, it is even more preferable that it is located at a distance of 20% or more of the height dimension H connecting the vertex 50 of the roughly triangular face portion 37 and the top horizontal fold line 26 from the top horizontal fold line 26, and at a distance of 25% or less of the width dimension W from the top horizontal fold line 26.

[0035] Furthermore, the body panel 8 has a second auxiliary fold line 58 that extends symmetrically from the lower end 51 of the first auxiliary fold line 48 in the left-right direction, and is either straight or curved downwards.

[0036] In this example, the second auxiliary fold line 58 is straight. The downward curve of the second auxiliary fold line 58 can be, for example, an arc as shown in Figure 3, a V-shaped angular arc as shown in Figure 4, or an angular arc made up of polygons as shown in Figure 5. The left and right ends 56 and 57 of the second auxiliary fold line 58 are located on a second imaginary line L2 parallel to the top horizontal fold line 26, with the first auxiliary fold line 48 in between.

[0037] The width dimension between the left and right ends 56 and 57 of the second auxiliary fold line 58 is preferably 20% to 60% of the width dimension of the top horizontal fold line when the second auxiliary fold line 58 is straight, and preferably 20% to 90% of the width dimension of the top horizontal fold line when the second auxiliary fold line 58 is arc-shaped or angular. In this example, the left and right ends 56 and 67 of the second auxiliary fold line 58 are located on the third virtual line L3 and the fourth virtual line L4, which connect the vertex 50 of the roughly triangular face portion 37 of the gable wall forming panel 24 with the intersection points 59 and 60 of the left and right ends of the body vertical fold lines 4 and 5 of the body panel 8 and the left and right ends of the bottom horizontal fold line 42.

[0038] Furthermore, the width of the body panels 6, 7, 8, and 9, which are one of the factors determining the size of the paper container 1, and the basis weight of the cardboard material forming the paper container 1 are not particularly limited. However, in the first example, the width of the body panels 6, 7, 8, and 9 is 57 mm or less, and the basis weight of the cardboard material is 150-260 g / m². 2 That's how it is.

[0039] In the paper container of this example, which is configured as described above, the roughly triangular surface portion 37 enclosed by the folding lines 34, 35 and the top horizontal fold line 26 in the end wall forming panel 24, and the body panel 8 connected to the end wall forming panel 24, have a first auxiliary fold line 48 that straddles the top horizontal fold line 26, located on a first virtual line L1 that is approximately perpendicular to the top horizontal fold line 26 at approximately the center of the top horizontal fold line 26, and is formed along this first virtual line L1. Furthermore, the body panel 8 has a second auxiliary fold line 58 that is straight or downward curved and extends in the left-right direction from the lower end 51 of the first auxiliary fold line 48. As a result, the bending strength of the portion where the top horizontal fold line 26 and the first auxiliary fold line 48 intersect at the top corner portion 52 of the body portion 13 formed by the top horizontal fold line 26 is reduced. When the top corner 52 is pressed in, the roughly triangular face portion 37 of the gable wall forming panel 24 folds inward from the first auxiliary fold line 48, and the body panel 8 is influenced by the fold of the roughly triangular face portion 37 from the first auxiliary fold line 48 to fold inward from the second auxiliary fold line 58. At the same time, it buckles and folds inward from imaginary lines L5 and L6 connecting the left and right ends 56 and 57 of the second auxiliary fold line 58 and the left and right ends of the body vertical fold lines 4 and 5 of the body panel 8 and the left and right ends of the top horizontal fold line 26, which induces the central part of the top corner 52 to fold inward from the paper container 1. As a result, the top corner 52 can be pressed inward from the paper container 1 with little force, and the roughly triangular face portion 37 of the gable wall forming panel 24 and the upper part of the body panel 8 can be recessed more easily and effectively.

[0040] If only the first auxiliary fold line 48 is folded inward, the lower end 51 of the first auxiliary fold line 48 on the body panel 8 will be convex to enclose the concave shape. However, since only the imaginary lines (not shown) connecting the lower end 51 of the first auxiliary fold line 48 and the intersections 53 and 54 of the left and right body vertical fold lines 4 and 5 on the body panel 8 and the left and right ends of the top horizontal fold line 26 are buckled, it serves as a damper but lacks reliability and is also weak against forces trying to return to its original shape. Since the auxiliary fold line 58 is formed, the second auxiliary fold line 58 folds in a mountain shape to divide the body panel 8 into upper and lower sections in response to the force that attempts to create a recess in the body panel 8 by the first auxiliary fold line 48 on the body panel 8. This promotes buckling at imaginary lines L5 and L6, which connect the ends 56 and 57 of the second auxiliary fold line 8 with the ends 53 and 54 of the body panel 8 with the ends 4 and 5 of the body vertical fold lines 4 and 5 on the left and right sides of the body panel 8 with the ends 2 and 5 of the top horizontal fold line 26. This mountain fold allows the lower end point 51 of the first auxiliary fold line 48 to easily become a convex portion.

[0041] Furthermore, since three continuous surfaces are formed on the same plane at a single point, indenting one common edge will cause the remaining edges to become convex. When the gable wall forming panel 24, which is folded between the pair of gable roof forming panels 16 and 17, is pulled out and the body panel 8 is pushed inward, it will buckle and fold at the second auxiliary fold line 58 from imaginary lines L5 and L6 connecting the intersection points 53 and 54 of the intersection points 56 and 57 of the second auxiliary fold line 58 and the left and right ends 56 and 57 of the second auxiliary fold line 58 with the left and right ends of the body vertical fold lines 4 and 5 of the body panel 8 and the left and right ends of the top horizontal fold line 26. This is because the first auxiliary fold line 48 is indented when opened, and pairs of V-shaped shapes are formed on the left and right sides of the axis. This is the reverse of the above shape, and it is related to the action of holding the body panel 6 opposite the body panel 8 on the spout side 22, where the first auxiliary fold line 48 is located, from the front and back directions when drinking directly from the spout 22.

[0042] Furthermore, when pouring liquid contents from the square paper container 1, the body 13 is held from both sides on the spout 22 side, so the first auxiliary crease 48, which is already creased when opened, easily becomes a mountain fold, and the upper end of the body panel 8 from the roughly triangular surface 37 becomes convex, making it easy to pour. Moreover, when drinking directly from the spout 22, the body panel 6 opposite the body panel 8 on the spout 22 side with the first auxiliary crease 48 is held from the front and back directions, so the lower end 51 of the first auxiliary crease 48 on the body panel 8 is recessed, which effectively suppresses the return of the roughly triangular surface 37 and the body panel 8, which are protruding from the first auxiliary crease 48, in the direction of the valley fold, and the shape of the open spout 22 can be maintained, resulting in a paper container 1 with a spout shape that is easy to drink directly from without being affected by the top horizontal crease 26.

[0043] Furthermore, if the upper end portion 49 of the approximately triangular face portion 37 of the gable wall forming panel 24 is located at or near the vertex 50 of the approximately triangular face portion 37, and the lower end portion 51 of the first auxiliary fold line 48 on the body panel 8 is located at a distance of 20% or more of the height dimension H connecting the vertex 50 of the approximately triangular face portion 37 and the top horizontal fold line 26 from the top horizontal fold line 26, then when the top corner portion 52 is pressed in, the approximately triangular face portion 37 and the body panel 8 can be valley-folded from the first auxiliary fold line 48 and the body panel 8 can be mountain-folded from the second auxiliary fold line 58, so that the top corner portion 52 can be pressed in with less force and folded inward into the paper container 1.

[0044] Furthermore, if the lower end 51 of the first auxiliary fold line 48 on the body panel 8 is located at a distance of 20% or more from the top horizontal fold line 26 by the height dimension H connecting the vertex 50 of the roughly triangular face portion 37 of the gable wall forming panel 24 and the top horizontal fold line 26, then the area of ​​the triangular portion at the top of the body panel 8, connecting the end of the top horizontal fold line 26 and the lower end 51 of the first auxiliary fold line 48 on the body panel 8, is secured. By making a valley fold of the top horizontal fold line 26, a triangle can be created connecting the vertex 50 of the roughly triangular face portion 37, the end of the top horizontal fold line 26 and the lower end 51 of the first auxiliary fold line 48 on the body panel 8. As a result, the pair of V-shapes created on the left and right sides with the first auxiliary fold line 48 as the axis become more stable and it becomes easier to maintain their concave state. Furthermore, by bending the top corner 52 and recessing the roughly triangular surface 37 and the upper part of the body panel 8, the space 55 that opens between the pair of gable roof forming panels 16, 17, the body panel 8 and the gable wall forming panel 24 can be made into a space 55 large enough to insert a finger.

[0045] Furthermore, if the lower end 51 of the first auxiliary fold line 48 in the body panel 8, where the second auxiliary fold line 58 is formed, is located at a distance of 20% or more from the top horizontal fold line 26 of the height dimension H connecting the vertex 50 of the approximately triangular face portion 37 of the gable wall forming panel 24 and the top horizontal fold line 26, and at a distance of 25% or less from the top horizontal fold line 26 of the width dimension W of the top horizontal fold line 26, then when the top corner portion 52 is pressed, the body panel 8 will reliably valley fold all the way to the lower end 51 of the first auxiliary fold line 48 without bending in the middle of the first auxiliary fold line 48, and will reliably induce a mountain fold from the second auxiliary fold line 58.

[0046] Furthermore, since the second auxiliary fold line 58 has its left and right ends 56 and 57 positioned on a second imaginary line l2 parallel to the top horizontal fold line 26, with the first auxiliary fold line 48 in between, the force applied when the top corner 52 is pressed is evenly distributed to the left and right ends 56 and 57 of the second auxiliary fold line 58. This allows the approximately triangular surface portion 37 of the gable wall forming panel 24 and the upper part of the body panel 8 to be recessed more easily and effectively in a stable state. Furthermore, by pulling out the gable wall forming panel 24 which is folded between the pair of gable roof forming panels 16 and 17, the return of the roughly triangular surface portion 37 and the body panel 8, which protrude from the first auxiliary fold line 48 by a mountain fold, is more effectively suppressed in the valley fold direction, and the shape of the open spout 22 can be maintained in good condition.

[0047] Furthermore, since the left and right ends 56 and 57 of the second auxiliary fold line 58 are located on the third and fourth imaginary lines L3 and L4, which connect the vertex 50 of the roughly triangular face portion 37, the ends of the left and right torso vertical fold lines 4 and 5 of the torso panel 8, and the left and right ends of the bottom horizontal fold line 42, when the top corner portion 52 is pressed in, the torso panel 8 buckles and folds with less force from the imaginary lines L5 and L6, which connect the left and right ends 56 and 57 of the second auxiliary fold line 58, the ends of the left and right torso vertical fold lines 4 and 5 of the torso panel 8, and the left and right ends of the top horizontal fold line 26, compared to the case where the left and right ends 56 and 57 of the second auxiliary fold line 58 are located outside the third and fourth imaginary lines L3 and L4, the torso panel 8 buckles and folds with less force from the imaginary lines L5 and L6, which connect the left and right ends 56 and 57 of the second auxiliary fold line 58, the ends of the left and right torso vertical fold lines 4 and 5 of the torso panel 8, and the left and right ends of the top horizontal fold line 26, the roughly triangular face portion 37 of the gable wall forming panel 24 and the upper part of the torso panel 8 can be recessed more easily.

[0048] Sensory evaluation tests were conducted on the ease of bending the top corner 52 and the ease of inserting a finger into the space 55 in the examples and comparative examples shown below. The examples and comparative examples used paper containers in which the height dimension H connecting the vertex 38 of the approximately triangular surface portion 37 of the gable wall forming panel 24 to the top horizontal fold line 26 was 31.02 mm, and the width dimension W of the top horizontal fold line 26 was 58 mm.

[0049] [Example 1] The dimension from the top horizontal fold line 26 to the bottom end 51 of the body panel 8 at the first auxiliary fold line 48 was set to 7.5 mm (height ratio H: 24.2%, width ratio W: 13.0%), and the dimension of the second auxiliary fold line 58 was set to 14.2 mm (width ratio W: 24.5%). [Example 2] The dimension from the top horizontal fold line 26 to the bottom end 51 of the body panel 8 at the first auxiliary fold line 48 was set to 7.5 mm (height ratio H: 24.2%, width ratio W: 13.0%), and the dimension of the second auxiliary fold line 58 was set to 28.5 mm (width ratio W: 49.1%). [Example 3] The dimension from the top horizontal fold line 26 to the bottom end 51 of the body panel 8 at the first auxiliary fold line 48 was set to 11 mm (height ratio H: 35.5%, width ratio W: 19.0%), and the dimension of the second auxiliary fold line 58 was set to 28.5 mm (width ratio W: 49.1%). [Example 4] The dimension from the top horizontal fold line 26 to the bottom end 51 of the body panel 8 at the first auxiliary fold line 48 was set to 11 mm (height ratio H: 35.5%, width ratio W: 19.0%), and the dimension of the second auxiliary fold line 58 was set to 34.2 mm (width ratio W: 59.0%). [Comparative Example] No auxiliary fold lines for the first and second sections.

[0050] The evaluation results are as follows: Example 1...○ Example 2...○ Example 3...◎ Example 4...◎ Comparative example ···× [Evaluation details] ◎: The center of the top corner can be folded and pushed into the inside of the paper container with minimal force, and the resulting indentation provides enough space to insert a finger. ○: The center of the top corner can be folded and pushed inwards into the paper container with minimal force, and the resulting indentation provides space to insert a finger. ×: It was difficult to fold and push the center of the top corner inward into the paper container with little force, requiring considerable force. Also, the space created by the indentation was not consistent depending on the force applied, making it difficult to secure enough space to insert a finger. [Explanation of Symbols]

[0051] 1 paper container 2 carton blanks 3,4,5 Vertical fold lines on the torso 6,7,8,9 Body panels 10. Vertical fold lines on the torso 11 Vertical sealing panel 12 Edge 13 Torso 14,15 Outer top seal panel 16,17 Gable roof forming panels 18,19 Top horizontal fold line 20,21 Inner top seal panel 22 spout 23,24 End wall forming panel 25,26 Top horizontal fold line 27,28 Guide lines 29 First half cut 30 Second Half Cut 31. Spout for straw 32, 33, 34, 35 Folding lines 36,37 Almost triangular surface part 38 Top 39,40 Bottom forming panel 41,42 Bottom transverse fold line 43,44 Inner panel 45,46 Bottom transverse fold line 47 Bottom 48 1st auxiliary fold line 49 Upper end 50 vertices 51 Lower end 52 Top corner 53,54 intersection 55 Space 56, 57 End 58 2nd auxiliary fold line 59,60 intersection L1 First Virtual Line L2 Second Virtual Line L3 Third Virtual Line L4 4th virtual line L5, L6 virtual lines H Height dimension W width dimension

Claims

1. In a gable-roof type paper container, the container is made of a cardboard material with thermoplastic resin laminated on its front and back surfaces, and comprises four body panels, the edges of which are joined by vertical sealing panels to form a square body, and at the upper end of the body panels, a pair of gable roof forming panels facing each other and having an outer top sealing panel on top, and a pair of gable wall forming panels facing each other and having an inner top sealing panel on top, with one of them serving as a spout for opening, are connected via a top horizontal fold line, the pair of gable wall forming panels are folded between the pair of gable roof forming panels by valley folding along a folding line, the top is formed when the outer top sealing panel and the inner top sealing panel are heated and sealed at a predetermined position, and at the lower end of the body panels, a bottom forming panel and an inner panel are connected via a bottom horizontal fold line, and the bottom is formed when the inner panel is folded inside the bottom forming panel. In the opening side of the end wall forming panel, the substantially triangular surface portion enclosed by the folding line and the top horizontal fold line, and in the opening side of the body panel connected to the end wall forming panel, a first auxiliary fold line that straddles the top horizontal fold line is located on a first imaginary line that is substantially perpendicular to the top horizontal fold line at approximately the center position of the top horizontal fold line, and is formed along this first imaginary line. Furthermore, the body panel has a second auxiliary fold line that is straight or curved downward, extending left and right from the lower end of the first auxiliary fold line, wherein the upper end of the substantially triangular face portion of the gable wall forming panel is located at or near the vertex of the substantially triangular face portion, the lower end of the first auxiliary fold line on the body panel is located at a distance of 20% or more from the top horizontal fold line by the height dimension connecting the vertex of the substantially triangular face portion of the gable wall forming panel and the top horizontal fold line, the left and right ends of the second auxiliary fold line are located on a second imaginary line parallel to the top horizontal fold line, and the left and right ends of the second auxiliary fold line are located on a third imaginary line and a fourth imaginary line that connect the intersection of the vertex of the substantially triangular face portion of the gable wall forming panel, the ends of the left and right body vertical fold lines of the body panel, and the left and right ends of the bottom horizontal fold line, respectively, making it a paper container.

2. The paper container according to claim 1, characterized in that the lower end of the first auxiliary fold line is located at a point where it is 25% or less of the width dimension of the top horizontal fold line from the top horizontal fold line.

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