Paper container

Abstract

In order to obtain a gable-top type paper container with which it is possible to achieve easy stacking and storage space-saving during transportation or the like, a paper container 1 is formed of a carton blank 2 having side forming panels 15, 16, which are provided with foldout oblique guidelines 24 that connect a middle point A of a second top seal transverse folding line 20 to both ends B of a second apex transverse folding line 14, the carton blank 2 being configured such that the angle θ1 between the foldout oblique guidelines 24 and the second apex transverse folding line 14 provided on the side forming panels 15, 16 is 45 to 46 degrees, inclusive.

Description

Paper containers

[0001] The present invention relates to a paper container for containing liquid contents.

[0002] Conventionally, a paper container for containing liquid contents such as milk or juice has been made of a paperboard material with a thermoplastic resin laminated on the front and back surfaces thereof, and has a rectangular cylindrical body portion, which is made of a paperboard material with a thermoplastic resin laminated on the front and back surfaces thereof, and has a body front panel, left and right side panels, and a body back panel, which are connected via a body vertical fold line, and which forms a top portion, which is made of a pair of top forming panels connected to the body front panel and the body back panel via a first top horizontal fold line, a pair of side forming panels connected to the left and right side panels via a second top horizontal fold line, a pair of outer top seal panels connected to the upper ends of the pair of top forming panels via a first top seal horizontal fold line, and a pair of side forming panels connected to the upper ends of the pair of top forming panels via a first top seal horizontal fold line. A paper container is widely used which has a top formed from a carton blank having a pair of inner top seal panels connected to the upper end of a face forming panel via a second top seal horizontal fold line, the pair of top forming panels and the pair of side forming panels connected to each other via a top vertical fold line, the pair of side forming panels having a slanted folding line connecting the midpoint of the second top seal horizontal fold line to both ends of the second top horizontal fold line, the pair of side forming panels being folded between the pair of top forming panels, and the outer top seal panel and inner top seal panel being sealed (see, for example, Patent Document 1).

[0003] Paper containers with tops formed in this way are generally called gable-top or gable-roof types, and the top surface that forms the top is steeply inclined. Therefore, when trying to stack a large number of paper containers and store them in a box, for example during transportation, the bottom of the upper paper container rests on the steeply inclined top of the lower paper container, making it unstable and difficult to stack the paper containers. Furthermore, even if they are stacked, a large space will be created between the upper and lower paper containers, resulting in an unnecessarily large volume of the storage box that stores the paper containers.

[0004] To solve this problem, it is desirable to make the side edges of the top surface forming panel that forms the top of the paper container parallel to or at an angle close to parallel to the upper edge of the body forming panel that forms the tubular body.

[0005] Japanese Patent Application Laid-Open No. 2019-123540

[0006] However, it has been considered difficult to manufacture the paper container so that the side edge of the top surface forming panel that forms the top of the paper container and the upper edge of the body forming panel that forms the tubular body are parallel or at an angle close to parallel.

[0007] The inventors conducted extensive testing and research to ensure that the side edges of the top forming panel of a paper container and the upper edges of the body forming panels are parallel or at an angle close to parallel. As a result, they found that by focusing, during the design stage of the carton blanks, on the angle between the slanted fold line on the pair of side forming panels and the second top horizontal fold line between the side forming panels and the left and right side panels of the body, the ratio of the length from the bottom end of the outer top seal panel to the second top horizontal fold line, and the thickness of the paperboard material, and specifying the angle between the slanted fold line and the second top horizontal fold line, the ratio of the length from the bottom end of the outer top seal panel to the second top horizontal fold line, and the position of the first top horizontal fold line relative to the second top horizontal fold line, they were able to ensure that the side edges of the top forming panel that forms the top of a paper container and the upper edges of the body forming panels that form the tubular body are parallel or at an angle close to parallel, thereby completing the present invention.

[0008] An object of the present invention is to provide a paper container having a gable-top type top structure, which can be easily stacked during transportation and can save space for storage.

[0009] In order to achieve the above object, the invention described in claim 1 provides a bag made of a paperboard material having a thermoplastic resin laminated on both sides thereof, the bag having a rectangular tubular body portion, a body front panel, left and right side panels, and a body back panel, which are connected via a body vertical fold line, the bag having a top portion, a pair of top forming panels connected to the body front panel and the body back panel via a first top horizontal fold line, a pair of side forming panels connected to the left and right side panels via a second top horizontal fold line, a pair of outer top seal panels connected to upper ends of the pair of top forming panels via a first top seal horizontal fold line, and a pair of inner top seal panels connected to upper ends of the pair of side forming panels via a second top seal horizontal fold line, A paper container is formed from carton blanks in which a pair of top forming panels and the pair of side forming panels are connected to each other via a top vertical fold line, and the pair of side forming panels have slanted fold lines that connect the midpoint of the second top seal horizontal fold line to both ends of the second top horizontal fold line, and the top is formed by folding the pair of side forming panels between the pair of top forming panels and sealing the outer top seal panel and the inner top seal panel.The carton blank is characterized in that the angle θ between the slanted fold lines on the pair of side forming panels and the second top horizontal fold line is 45 degrees or more and 46 degrees or less.

[0010] According to the invention described in claim 1, in the carton blanks, the angle θ between the slanted folding line provided on the pair of side forming panels and the second top horizontal fold line is 45 degrees or more and 46 degrees or less, so that the formed paper container has an angle such that the side edges of the top forming panel that form the top surface of the top and the upper edge of the body forming panel are parallel or nearly parallel, i.e., the angle between the side edges of the top forming panel and the body forming panel is 0 degrees or nearly 0 degrees, and a paper container with a generally flat top surface can be obtained.

[0011] The invention described in claim 2 is a box made of a paperboard material laminated with a thermoplastic resin on both sides, the box having a rectangular tubular body portion, a body front panel, left and right side panels, and a body back panel, which are connected via a body vertical fold line, and the box has a top portion, a pair of top forming panels connected to the body front panel and the body back panel via a first top horizontal fold line, a pair of side forming panels connected to the left and right side panels via a second top horizontal fold line, a pair of outer top seal panels connected to upper ends of the pair of top forming panels via a first top seal horizontal fold line, and a pair of inner top seal panels connected to upper ends of the pair of side forming panels via a second top seal horizontal fold line, the pair of top forming panels and the A pair of side forming panels are connected to each other via a top vertical fold line, and the pair of side forming panels are formed from carton blanks in which a folding inclined line connecting the midpoint of the second top seal horizontal fold line to both ends of the second top horizontal fold line is provided, and the pair of side forming panels are folded between the pair of top forming panels, and the outer top seal panel and the inner top seal panel are sealed to form a top 2. In this paper container, the length from the lower end of the outer top seal panel to the second top horizontal fold line in the carton blank is at least 1 / 2 the length of the second top horizontal fold line and is not more than 1 / 2 the length of the second top horizontal fold line plus half the paper thickness of the paperboard material.

[0012] According to the invention described in claim 2, in the carton blanks, the length from the lower end of the outer top seal panel to the second top horizontal fold line is at least 1 / 2 the length of the second top horizontal fold line and is not more than 1 / 2 the length of the second top horizontal fold line plus half the paper thickness of the paperboard material, so that the formed paper container has a side edge of the top forming panel that forms the top surface of the top and an upper edge of the body forming panel that are parallel or close to parallel, i.e., the angle between the side edge of the top forming panel and the body forming panel is 0 degrees or close to 0 degrees, and a paper container with a generally flat top surface can be obtained.

[0013] The invention described in claim 3 is characterized in that, in the carton blank described in claim 1 or 2, the first top horizontal fold line is located above the second top horizontal fold line at a distance 2 to 4 times the paper thickness of the paperboard material.

[0014] According to the invention described in claim 3, in the carton blank, the first top horizontal fold line is located above the second top horizontal fold line at a distance that is 2 to 4 times the paper thickness of the paperboard material.Therefore, when the pair of top forming panels are folded in opposite directions from the first top horizontal fold line so as to fold the pair of side forming panels in between, resistance to folding that occurs when the folded portions overlap the upper surfaces of the pair of lower side forming panels can be effectively prevented.

[0015] As described above, the paper container according to the present invention can have a generally flat top surface, which makes it easy to stack during storage and transportation and saves space required for storage.

[0016] Figure 7 is a perspective view showing a first example of an embodiment of a paper container according to the present invention. Figure 8 is a plan view showing carton blanks that form the paper container shown in Figure 1. Figure 9 is a partially enlarged explanatory view of the carton blanks shown in Figure 2. Figure 10 is an explanatory view showing the top surface of the top of the paper container shown in Figure 1 that is formed from the carton blanks of Figure 2. Figure 11 is an explanatory view showing an example of stacking paper containers of the first example. Figure 12 is an explanatory view showing another example of stacking paper containers of the first example. Figure 13 is a plan view showing carton blanks that form a second example of an embodiment of a paper container according to the present invention. Figure 14 is an partially enlarged explanatory view of the carton blanks shown in Figure 7.

[0017] Hereinafter, an embodiment of a paper container according to the present invention will be described in detail with reference to the drawings. Figures 1 to 6 show a first embodiment of a paper container according to the present invention, in which Figure 1 is a perspective view of the paper container of the first embodiment, Figure 2 is a plan view of carton blanks for the paper container shown in Figure 1, Figure 3 is an enlarged explanatory view of a portion of the carton blank shown in Figure 2, Figure 4 is an explanatory view showing the top surface of the top of the paper container shown in Figure 1 formed from the carton blanks of Figure 2, Figure 5 is an explanatory view showing an example of stacking paper containers of the first embodiment, and Figure 6 is an explanatory view showing another example of stacking paper containers of the first embodiment.

[0018] The paper container 1 of the first example is formed from a carton blank 2, which is a paperboard material with a thermoplastic resin laminated on the front and back surfaces as shown in Figure 2. The carton blank 2 has a body front panel 4, a body left side panel 5, a body right side panel 6, and a body back panel 7, which are connected via a body vertical fold line 3.

[0019] When the paper container 1 is formed, the body front panel 4, the body left side panel 5, the body right side panel 6, and the body back panel 7 are joined to the vertical seal panel 8 connected to the body right side panel 6 via the body vertical fold line 3 and the edge 9 of the body back panel 7 to form a square tubular body 10 of the paper container 1.

[0020] The upper ends of the front body panel 4 and the back body panel 7 have a pair of top forming panels 12, 13 connected via a first top horizontal fold line 11, and the upper ends of the left body side panel 5 and the right body side panel 6 have a pair of side forming panels 15, 16 connected via a second top horizontal fold line 14.

[0021] The top forming panels 12, 13 have a pair of outer top seal panels 18, 19 connected to their upper ends via a first top seal horizontal fold line 17, and the side forming panels 15, 16 have a pair of inner top seal panels 21, 22 connected to their upper ends via a second top seal horizontal fold line 20. The top forming panels 12, 13 and the side forming panels 15, 16 are connected to each other via a top vertical fold line 23.

[0022] In addition, the pair of side forming panels 15, 16 are provided with inclined folding lines 24 for folding the side forming panels 15, 16, which connect the midpoint A of the second top seal horizontal fold line 20 to both end portions B of the second top horizontal fold line 14.

[0023] When forming the paper container 1, the side forming panels 15, 16 are folded between the top forming panels 12, 13, and the outer top seal panels 18, 19 and the inner top seal panels 21, 22 are sealed to form a gable-top top 25 as shown in Figure 1.

[0024] In the carton blank 2 configured as described above, the angle θ1 between the fold-in inclined line 24 formed on the pair of side forming panels 15, 16 and the second top horizontal fold line 14 is between 45 degrees and 46 degrees.

[0025] The angle θ1 is determined as the angle at which the side edge 25b of the top surface 25a of the top 25 of the formed paper container 1 and the upper edge 10a of the tubular body 10 are parallel or nearly parallel, i.e., the angle θ2 between the side edge 25b of the top surface 25a of the top 25 and the upper edge 10a of the tubular body 10 is 0 degrees or nearly 0 degrees.

[0026] Furthermore, in the first example, the first top horizontal fold line 11 is spaced above the second top horizontal fold line 14 by a length L1 that is two to four times the thickness of the paperboard material. The length L1 is determined to facilitate folding of the top surface forming panels 12, 13 from the first top horizontal fold line 11 and to provide a flatter top surface 25a with less bulging at the folded portion.

[0027] In the first example, the lower ends of the front body panel 4 and the back body panel 7 have bottom forming panels 27, 28 connected via a first horizontal bottom fold line 26, and the lower ends of the left side body panel 5 and the right side body panel 6 have inner panels 30, 31 connected via a second horizontal bottom fold line 29. When forming the paper container 1, the inner panels 30, 31 are folded inside the bottom forming panels 27, 28 and the abutting surfaces are bonded together to form the bottom 32 of the paper container 1.

[0028] In the paper container 1 formed from the carton blanks 2 configured in this manner, the angle θ1 between the slanted folding line 24 formed on the pair of side forming panels 15, 16 and the second top horizontal fold line 14 in the carton blanks 2 forming the paper container 1 is between 45 degrees and 46 degrees, and therefore the formed paper container 1 has an angle such that the side edges 25b of the top forming panels 12, 13 that form the top surface 25a of the top 25 and the upper edges 10a of the left body side panel 5 and the right body side panel 6 that form the tubular body 10 are parallel or nearly parallel, i.e., the angle θ2 between the side edges 25b of the top forming panels 12, 13 and the upper edges 10a of the left body side panel 5 and the right body side panel 6 is 0 degrees or nearly 0 degrees, and a paper container 1 having a generally flat top surface 25b can be obtained (see Figures 1 and 4).

[0029] Therefore, when paper containers 1 are stacked so that they straddle the top surfaces of two adjacent lower paper containers 1, the bottom 32 of the upper paper container 1 is stacked stably on the top surface 25a formed by the top surface forming panels 12, 13 of the top 25, avoiding the top seal portion 33 of the lower paper container 1 (see Figure 5), and the space between the top 25 of the lower stacked paper container 1 and the bottom 32 of the upper stacked paper container 1 is reduced, allowing for space savings in storage.

[0030] If the angle θ1 between the fold-in inclined line 24 formed on the side forming panels 15, 16 and the second top horizontal fold line 14 is 45 degrees or less, it will be difficult to join the opposing surfaces of the opposing outer top seal panels 18, 19 and inner top seal panels 21, 22 when forming the top 25, making it impossible to ensure the integrity of the seal of the outer top seal panels 18, 19 and inner top seal panels 21, 22, or making it easier for forces to be applied to the sealed outer top seal panels 18, 19 and inner top seal panels 21, 22 in a direction that would cause the seal to peel off, which could result in the seal peeling off.

[0031] Furthermore, if the angle θ1 is 46 degrees or more, the angle θ2 formed by the side edge 25b of the top forming panels 12, 13 and the upper edge 10a of the left side panel 5 and the right side panel 6 of the body becomes an angle that makes it difficult to obtain satisfactory stability for the paper container 1 stacked on top of the paper container 1, and also, there is no satisfactory space between the top 25 of the lower paper container 1 and the bottom 32 of the upper paper container 1 to save space in storage.

[0032] In addition, in the first example, the first top horizontal fold line 11 is located above the second top horizontal fold line 14 by a length L1 that is 2 to 4 times the thickness of the paperboard material. Therefore, when the top forming panels 12, 13 are folded in the opposite direction from the first top horizontal fold line 11 with the side forming panels 15, 16 folded in between, the resistance to bending caused by the top forming panels 12, 13 overlapping the upper surface of the lower side forming panels 15, 16 that overlap the bending portion C of the top forming panels 12, 13 that are bent from the first top horizontal fold line 11 is small, and the top forming panels 12, 13 can be easily folded from the first top horizontal fold line 11.

[0033] Furthermore, since the first top horizontal fold line 11 is located above the second top horizontal fold line 14 by a distance L1 that is 2 to 4 times the thickness of the paperboard material, a gap D corresponding to the length L1 that is 2 to 4 times the thickness of the paperboard material is created between the side edges 25b of the top forming panels 12, 13 and the upper edges 10a of the left side panel 5 and the right side panel 6 of the body (see Figure 4).

[0034] Therefore, when stacking paper containers 1, if the top seal portion 33 of the lower paper container 1 is tilted down and a paper container 1 is placed on top of it, the weight of the upper paper container 1 causes the top surface 25a to elastically deform the paperboard material, pushing the tilted top seal portion 33 into the gap D, and the top seal portion 33 sinks below the folding portion C of the top surface forming panels 12, 13 that are folded from the first top horizontal fold line 11 (see Figure 6), making it possible to stack paper containers 1 stably in a single vertical row, thereby further saving storage space.

[0035] If the distance between the first top horizontal fold line 11 and the second top horizontal fold line 14 is less than twice the paper thickness of the paperboard material, the gap D between the side edge 25b of the top forming panels 12, 13 and the upper edge 10a of the left side panel 5 of the body and the right side panel 6 of the body will be narrow, and when the top seal portion 33 of the lower paper container 1 is folded down and a paper container 1 is stacked on top of it, the top seal portion 33, which is pushed into the gap D by the weight of the upper paper container 1, will protrude above the folding portion C of the top forming panels 12, 13 that are folded from the first top horizontal fold line 11, making it difficult to stack the paper containers 1 in a stable vertical line.

[0036] Furthermore, if the distance between the first top horizontal fold line 11 and the second top horizontal fold line 14 is four or more times the paper thickness of the paperboard material, the angle between the top surface forming panel 12 and the top surface forming panel 13 becomes large, and the deformation resistance strength of the top surface 25a becomes large.As a result, it becomes difficult to knock down the top seal portion 33 of the lower paper container 1 and push the knocked down top seal portion 33 into the gap D due to the elastic deformation of the paperboard material of the top surface 25a with the weight of the paper container 1 stacked on top of it, making it difficult to stack the paper containers 1 in a stable vertical row.

[0037] 7 and 8 show a second embodiment of the paper container according to the present invention, where FIG. 7 is a plan view showing a carton blank forming the paper container of the second embodiment, and FIG. 8 is an enlarged explanatory view of a portion of the carton blank shown in FIG. 7.

[0038] In the paper container 1 of the second example, the same components as those in the first example are given the same reference numerals and their explanations are omitted, and only the components different from those in the first example will be explained.

[0039] In the second example, in the carton blank 2, the length L2 from the lower end E of the outer top seal panels 18, 19, i.e., from the first top seal horizontal fold line 17 to the second top horizontal fold line 14, is at least 1 / 2 the length L3 of the second top horizontal fold line 14 and is not more than 1 / 2 the length L3 of the second top horizontal fold line plus half the paper thickness of the paperboard material.

[0040] The length L2 is determined as the length at which the side edge 25b of the top surface 25a of the top 25 of the formed paper container 1 and the upper edge 10a of the tubular body 10 are parallel or nearly parallel, i.e., the angle θ2 between the side edge 25b of the top surface 25a of the top 25 and the upper edge 10a of the tubular body 10 is 0 degrees or nearly 0 degrees.

[0041] Furthermore, in the second example, as in the first example, the first top horizontal fold line 11 is spaced above the second top horizontal fold line 14 by a length L1 that is two to four times the thickness of the paperboard material. As in the first example, the length L1 is determined to be a length that allows the top surface forming panels 12, 13 to be easily folded from the first top horizontal fold line 11 and to obtain a flatter top surface 25a with less bulging at the folding portion C.

[0042] The paper container 1 formed from the carton blanks 2 configured in this manner has a length L2 from the lower end E of the outer top seal panels 18, 19, i.e., from the first top seal horizontal fold line 17 to the second top horizontal fold line 14, which is equal to or greater than half the length L3 of the second top horizontal fold line 14 and equal to or less than half the length L3 of the second top horizontal fold line + half the paper thickness of the paperboard material, so the formed paper container 1 has a length L2 from the lower end E of the outer top seal panels 18, 19 to the second top horizontal fold line 14, which is equal to or greater than half the length L3 of the second top horizontal fold line + half the paper thickness of the paperboard material, as in the first example. The side edges 25b of the top forming panels 12, 13 that form the top surface 25a of the paper container 10 are parallel or nearly parallel to the upper edges 10a of the left body side panel 5 and the right body side panel 6 that form the tubular body 10, i.e., the angle θ2 between the side edges 25b of the top forming panels 12, 13 and the upper edges 10a of the left body side panel 5 and the right body side panel 6 is 0 degrees or nearly 0 degrees, thereby obtaining a paper container 1 with a generally flat top surface 25a (see Figures 1 and 4).

[0043] Therefore, as in the first example, when paper containers 1 are stacked so that they straddle the top surfaces of two adjacent paper containers 1 below, the bottom 32 of the upper paper container 1 is stably stacked on the top surface 25a formed by the top surface forming panels 12, 13 of the top 25, avoiding the top seal portion 33 of the lower paper container 1, and the space between the top 25 of the lower stacked paper container 1 and the bottom 32 of the upper stacked paper container 1 is reduced, thereby enabling space saving in storage (Figure 5 cited).

[0044] If the length L2 from the lower end E of the outer top seal panels 18, 19, i.e., from the first top seal horizontal fold line 17 to the second apex horizontal fold line 14, is less than half the length L3 of the second apex horizontal fold line 14, as in the first example, it will be difficult to join the opposing surfaces of the opposing outer top seal panels 18, 19 and inner top seal panels 21, 22 when forming the apex 25, making it impossible to ensure the integrity of the seal between the outer top seal panels 18, 19 and inner top seal panels 21, 22, or making it easier for forces to be applied to the sealed outer top seal panels 18, 19 and inner top seal panels 21, 22 in a direction that would cause the seal to peel off, which could result in the seal peeling off.

[0045] Furthermore, if the length L2 from the first top seal horizontal fold line 17 to the second top horizontal fold line 14 is equal to or greater than 1 / 2 of the length L3 of the second top horizontal fold line plus half the paper thickness of the paperboard material, as in the first example, the angle θ2 formed by the side edge 25b of the top forming panels 12, 13 and the upper edge 10a of the left side panel 5 and the right side panel 6 of the body becomes an angle that makes it difficult to achieve satisfactory stability for the paper container 1 stacked on top of the paper container 1, and also, there is no satisfactory space between the top 25 of the lower paper container 1 and the bottom 32 of the upper paper container 1 to save space in storage.

[0046] In the second example, as in the first example, the first top horizontal fold line 11 is located above the second top horizontal fold line 14 by a distance L1 that is 2 to 4 times the thickness of the paperboard material. Therefore, as in the first example, when the top forming panels 12, 13 are folded in the opposite direction from the first top horizontal fold line 11 with the side forming panels 15, 16 folded in between, the resistance to bending caused by the top forming panels 12, 13 overlapping the upper surface of the lower side forming panels 15, 16 that overlap the bending portion C of the top forming panels 12, 13 that are bent from the first top horizontal fold line 11 is small, and the top forming panels 12, 13 can be easily folded from the first top horizontal fold line 11.

[0047] Furthermore, since the first top horizontal fold line 11 is located above the second top horizontal fold line 14 by a length L1 that is 2 to 4 times the thickness of the paperboard material, as in the first example, a gap D corresponding to the length L1 that is 2 to 4 times the thickness of the paperboard material is created between the side edge 25b of the top forming panels 12, 13 and the upper edge 10a of the left side panel 5 of the body and the right side panel 6 of the body (Figure 4 is used).

[0048] Therefore, when stacking paper containers 1, if the top seal portion 33 of the lower paper container 1 is tilted down and a paper container 1 is placed on top of it, the weight of the upper paper container 1 causes the elastic deformation of the paperboard material of the top surface 25a, pushing the tilted top seal portion 33 into the gap D, and the top seal portion 33 sinks below the folding portion C of the top surface forming panels 12, 13 that are folded from the first top horizontal fold line 11 (see Figure 6), making it possible to stack the paper containers 1 stably in a single vertical row, thereby further saving storage space.

[0049] If the distance between the first top horizontal fold line 11 and the second top horizontal fold line 14 is less than twice the thickness of the paperboard material, it becomes difficult to stably stack the paper containers 1 in a single vertical line, as in Example 1. If the distance between the first top horizontal fold line 11 and the second top horizontal fold line 14 is more than four times the thickness of the paperboard material, it becomes difficult to stably stack the paper containers 1 in a single vertical line, as in Example 1.

[0050] 1 Paper container 2 Carton blank 3 Body longitudinal fold line 4 Body front panel 5 Body left side panel 6 Body right side panel 7 Body back panel 8 Vertical seal panel 9 Edge 10 Cylindrical body 10a Top edge 11 First top horizontal fold line 12, 13 Top forming panel 14 Second top horizontal fold line 15, 16 Side forming panel 17 First top seal horizontal fold line 18, 19 Outer top seal panel 20 Second top seal horizontal fold line 21, 22 Inner top seal panel 23 Top vertical fold line 24 Inclined folding line 25 Top 25a Top surface 25b Side edge 26 First bottom horizontal fold line 27, 28 Bottom forming panel 29 Second bottom horizontal fold line 30, 31 Inner panel 32 Bottom 33 Top seal part

Claims

1. It is made of a paperboard material with a thermoplastic resin laminated on both the front and back surfaces, and has a front panel of the body portion, a left and right side panels of the body portion, and a back panel of the body portion, which are connected via a longitudinal fold line of the body portion to form a square cylindrical body portion. It also has a pair of top surface forming panels connected to the front panel of the body portion and the back panel of the body portion via a first top horizontal fold line to form the top, and a pair of side surface forming panels connected to the left and right side panels of the body portion via a second top horizontal fold line. It further has a pair of outer top seal panels connected to the upper ends of the pair of top surface forming panels via a first top seal horizontal fold line, and a pair of inner top seal panels connected to the upper ends of the pair of side surface forming panels via a second top seal horizontal fold line. The pair of top surface forming panels and the pair of side surface forming panels are connected to each other via a top longitudinal fold line. The pair of side surface forming panels are formed from carton blanks provided with folding inclined ruled lines connecting both ends of the second top horizontal fold line from the midpoint of the second top seal horizontal fold line. In the paper container where the pair of side surface forming panels are folded between the pair of top surface forming panels and the outer top seal panels and the inner top seal panels are sealed to form the top, in the carton blanks, the angle θ formed by the folding inclined ruled line formed on the pair of side surface forming panels and the second top horizontal fold line is 45 degrees or more and 46 degrees or less, the first top horizontal fold line is 2 to 4 times the paper thickness of the paperboard material above the second top horizontal fold line. A paper container characterized by this.

2. It is made of a paperboard material with a thermoplastic resin laminated on both the front and back surfaces, and has a front panel of the body part, a left and right side panel of the body part, and a back panel of the body part that are connected via a vertical fold line of the body part to form a square cylindrical body part. It also has a pair of top surface forming panels that are connected to the front panel of the body part and the back panel of the body part via a first top seal horizontal fold line to form the top, and a pair of side surface forming panels that are connected to the left and right side panels of the body part via a second top seal horizontal fold line. It further has a pair of outer top seal panels that are connected to the upper ends of the pair of top surface forming panels via a first top seal horizontal fold line, and a pair of inner top seal panels that are connected to the upper ends of the pair of side surface forming panels via a second top seal horizontal fold line. The pair of top surface forming panels and the pair of side surface forming panels are connected to each other via a top vertical fold line. The pair of side surface forming panels are formed from carton blanks provided with folding inclined ruled lines connecting both ends of the second top seal horizontal fold line from the midpoint of the second top seal horizontal fold line. In the paper container formed by folding the pair of side surface forming panels between the pair of top surface forming panels and sealing the outer top seal panels and the inner top seal panels, In the carton blanks, the length from the lower end of the outer top seal panel to the second top seal horizontal fold line is not less than 1 / 2 of the length of the second top seal horizontal fold line and not more than 1 / 2 of the length of the second top seal horizontal fold line plus 1 / 2 of the paper thickness of the paperboard material. The paper container is characterized in that the first top seal horizontal fold line is 2 to 4 times the paper thickness of the paperboard material above the second top seal horizontal fold line.

3. The paper container according to claim 1 or 2, characterized in that a gap corresponding to a length of 2 to 4 times the paper thickness of the paperboard material is formed between the side edges of the pair of top surface forming panels forming the top and the upper sides of the left side panel of the body part and the upper sides of the right side panel of the body part.