Side gusset-type pouch

Abstract

The present invention provides a side gusset-type pouch in which occurrence of delamination at or in the vicinity of a lower-end connection portion of side gusset films is prevented. Provided is a side gusset-type pouch 10 wherein at least one of left and right side gusset films 50 has a lower-side inclined edge portion 54b which has a bending guidance portion 54b-1 and a lower-end side connection portion 54b-2 that connects the lower end of the bending guidance portion 54b-1 and a lower-end connection portion 53a, and the lower-end side connection portion 54b-2 connects the lower end of the bending guidance portion 54b-1 and the lower-end connection portion 53a such that the lower-end connection portion 53a is positioned below a first virtual intersection point P1 at which a central virtual line L1 that passes through an upper-end connection portion 53b and the lower-end connection portion 53a and a bending virtual line L2 that is defined by the bending guidance portion 54b-1 intersect.

Description

Horizontal gusset pouch

[0001] The present invention relates to a horizontal gusset pouch having side gusset films disposed on both the left and right side portions of the pouch.

[0002] Previously, the present applicant has proposed in Patent Document 1 a horizontal gusset-type pouch having side gusset films on both the left and right sides that are heat-sealed to the front and back films by side seals as a container for storing liquid contents such as drinking water or liquid detergent.

[0003] The side gusset films of the horizontal gusset pouch disclosed in Patent Document 1 have a front-side sealed region that is heat-sealed to the front film, a back-side sealed region that is heat-sealed to the back film, and a non-sealed region that is an area inside the front-side sealed region and the back-side sealed region, and the non-sealed region has a bottom end connecting portion that connects the lower end of the front-side outer edge that is the boundary with the front-side sealed region to the lower end of the back-side outer edge that is the boundary with the back-side sealed region. The bottom end connecting portion is located at the bottom of the pouch when the content liquid storage portion is filled with the content liquid and the pouch body is inflated.

[0004] Japanese Patent Application Laid-Open No. 2020-132177

[0005] However, it has been confirmed that when pressure is applied to the horizontal gusset pouch disclosed in Patent Document 1 while the pouch is filled with liquid contents, the heat-sealed films peel apart near the lower end joint of the side gusset films, which is known as delamination. When this delamination occurs, the seal between the films breaks, which may result in leakage of the liquid contents.

[0006] Therefore, the present invention solves these problems and aims to provide a horizontal gusset-type pouch with a simple configuration that suppresses delamination near the lower end connecting portion of the side gusset film, which is the area located at the bottom of the pouch when the content liquid storage section is filled with content liquid and the pouch body is inflated.

[0007] One aspect of the horizontal gusset pouch of the present invention is a horizontal gusset pouch comprising a front film, a back film, and side gusset films on both left and right sides that are disposed between the front film and the back film and are heat-sealed to the front film and the back film by side seals, wherein the side gusset films have a front-side sealed region that is heat-sealed to the front film at the side seals, a back-side sealed region that is heat-sealed to the back film at the side seals, and a non-sealed region that is a region inside the front-side sealed region and the back-side sealed region, and the non-sealed region has a front-side outer edge that is a boundary with the front-side sealed region and a back-side outer edge that is a boundary with the back-side sealed region, and the front-side outer edge and the back-side outer edge each have a base edge that is disposed at a distance from each other in the front-back direction, and a length that extends from the upper end of the base edge to the front The side gusset film has an upper inclined edge portion that extends to an upper end connecting portion that connects the upper ends of the outer edge and the back outer edge, and a lower inclined edge portion that extends from the lower end of the base edge portion to a lower end connecting portion that connects the lower ends of the front outer edge and the back outer edge, and at least one of the side gusset films on both the left and right sides has a lower inclined edge portion that has a folding induction portion that induces folding of the side gusset film when the content liquid storage portion is filled with content liquid, and a lower end connecting portion that connects the lower end of the folding induction portion and the lower end connecting portion, and the lower end connecting portion connects the lower end of the folding induction portion and the lower end connecting portion so that the lower end connecting portion is located lower than a first virtual intersection where a central virtual line passing through the upper end connecting portion and the lower end connecting portion intersects with a folding virtual line defined by the folding induction portion, thereby solving the problem.Another aspect of the horizontal gusset pouch of the present invention is a horizontal gusset pouch comprising a front film, a back film, and side gusset films on both the left and right sides that are disposed between the front film and the back film and are heat-sealed to the front film and the back film by side seals, wherein the side gusset films have a front-side sealed region that is heat-sealed to the front film at the side seals, a back-side sealed region that is heat-sealed to the back film at the side seals, and a non-sealed region that is a region inside the front-side sealed region and the back-side sealed region, and the non-sealed region has a front-side outer edge that is a boundary with the front-side sealed region and a back-side outer edge that is a boundary with the back-side sealed region, and the front-side outer edge and the back-side outer edge each have a base edge that is disposed at a distance from each other in the front-back direction, and a base edge that is a region extending from an upper end of the base edge to the front The side gusset film has an upper inclined edge portion extending to an upper end connecting portion that connects the upper ends of the side outer edge and the back outer edge, and a lower inclined edge portion extending from the lower end of the base edge portion to a lower end connecting portion that connects the lower ends of the front outer edge and the back outer edge, and at least one of the side gusset films on both the left and right sides has an upper inclined edge portion that has a folding induction portion that induces folding of the side gusset film when the content liquid is filled into the content liquid storage portion, and an upper end connecting portion that connects the upper end of the folding induction portion and the upper end connecting portion, and the upper end connecting portion connects the upper end of the folding induction portion and the upper end connecting portion so that the upper end connecting portion is located above a third virtual intersection where a central virtual line passing through the upper end connecting portion and the lower end connecting portion intersects with a folding virtual line defined by the folding induction portion, thereby solving the problem.

[0008] According to the present invention, with a simple configuration, it is possible to suppress the occurrence of delamination near the lower end connecting portion of the side gusset film, which is the area located at the bottom of the pouch when the content liquid is filled into the content liquid storage section and the pouch body is inflated.

[0009] 1 is an explanatory diagram showing a state in which a horizontal gusset pouch according to one embodiment of the present invention is placed on a placement surface. FIG. 2 is an explanatory diagram showing each film constituting the horizontal gusset pouch. FIG. 3 is an explanatory diagram showing one of the side gusset films. FIG. 4 is an explanatory diagram showing a lower portion of one of the side gusset films. FIG. 5 is an explanatory diagram showing an upper portion of one of the side gusset films. FIG. 6 is an explanatory diagram showing the other side gusset film. FIG. 7 is an explanatory diagram showing a lower portion of the other side gusset film. FIG. 8 is an explanatory diagram showing an upper portion of the other side gusset film. FIG. 9 is an explanatory diagram showing a schematic state in which a horizontal gusset pouch is placed on a placement surface. FIG. 10 is an explanatory diagram showing an aspect of a bottom seal. FIG. 11 is an explanatory diagram showing an example in which a folding control seal portion is not formed. FIG. 12 is an explanatory diagram showing a modified example of the bottom seal.

[0010] A horizontal gusset pouch 10 according to one embodiment of the present invention will be described below with reference to the drawings.

[0011] The horizontal gusset pouch 10 is for containing liquid contents such as drinking water or liquid detergent, and as shown in FIG. 1 , is configured as a pouch with gusset portions formed on both the left and right sides of the pouch in the left-right direction Z, and is configured so that the liquid contents can be poured out from a spout 70 attached to the side of the pouch body 20.

[0012] As shown in FIG. 1 , the horizontal gusset pouch 10 has a pouch body 20 formed into a bag shape by heat-welding flexible films 30, 40, 50, and 60 to form a bag-making seal portion, an inner film 60 placed inside the pouch body 20, and a spout 70 attached to the pouch body 20.

[0013] As shown in Figures 1 and 2, the pouch body 20 has a front film 30 and a back film 40 that are arranged opposite each other in the front-to-back direction X with the content liquid storage section 21 in between, and side gusset films 50 on both left and right sides that are arranged between the front film 30 and the back film 40 on both sides of the pouch side in the left-to-right direction Z and are heat-sealed to the front film 30 and the back film 40 by side seals 22.

[0014] Each of the films 30, 40, 50, and 60 is formed as a resin film having a heat-sealed layer on at least one side thereof, and is arranged so that the heat-sealed layers face each other at the locations where they are heat-sealed to each other. Note that in Figure 2 and other figures, the heat-sealed areas of each of the films 30, 40, 50, and 60 are indicated by solid lines.

[0015] 1 and 2, the pouch body 20 has side seals 22 formed by heat-welding both lateral sides of the side gusset film 50 to the films 30, 40, a top seal 23 formed contiguous with the left and right side seals 22 at the top of the pouch body 20 facing the bottom seal 24 across the content liquid storage section 21, a bottom seal 24 formed contiguous with the left and right side seals 22 at the pouch bottom 20a of the pouch body 20, and an intermediate seal 25 formed by heat-welding the films 30, 40 and the inner film 60. These seals 22 to 25 constitute a bag-making seal section.

[0016] The top seal 23 and the bottom seal 24 are formed by directly or indirectly heat-sealing the films 30, 40, and in this embodiment, they have portions where the films 30, 40 are directly heat-sealed, and portions where the films 30, 40 are indirectly heat-sealed by interposing an inner film 60 between the films 30, 40 (portions where the films 30, 60 are heat-sealed, between the films 60 themselves, and between the films 40, 60). If the inner film 60 is not provided, the top seal 23 and the bottom seal 24 are formed only from portions where the films 30, 40 are directly heat-sealed.

[0017] Furthermore, at a predetermined location (e.g., location A shown in FIG. 1 ) on the side of pouch body 20 where the gusset portion is formed, side gusset film 50 is partially removed to form a portion where films 30, 40 are heat-sealed together, thereby preventing films 30, 40 from separating from each other at the predetermined location (e.g., location A shown in FIG. 1 ).

[0018] As shown in Figures 3 and 6, the side gusset film 50 has a front seal area 51 that is heat-sealed to the front film 30 at the side seal 22, a back seal area 52 that is heat-sealed to the back film 40 at the side seal 22, and a non-seal area 53 that is the area inside the front seal area 51 and the back seal area 52.

[0019] As shown in FIGS. 3 and 6 , the non-sealed area 53 has a front outer edge 54 that is the boundary with the front seal area 51 and a back outer edge 55 that is the boundary with the back seal area 52 .

[0020] As shown in Figures 3 and 6, the front outer edge 54 and the back outer edge 55 each have base edges 54a, 55a that are spaced apart from each other in the front-to-back direction X, lower inclined edges 54b, 55b that extend from the lower ends of the base edges 54a, 55a to the lower end connecting portion 53a that connects the lower ends of the front outer edge 54 and the back outer edge 55, and upper inclined edges 54c, 55c that extend from the upper ends of the base edges 54a, 55a to the upper end connecting portion 53b that connects the upper ends of the front outer edge 54 and the back outer edge 55.

[0021] 3 and 6, the base edges 54a, 55a are formed to extend linearly in the up-down direction Y. Note that the base edges 54a, 55a may be formed in a form other than a straight line.

[0022] As shown in FIGS. 3 and 6, the lower inclined edges 54b, 55b are portions that extend at an angle in the up-down direction Y so as to move inward in the front-to-back direction X as they extend downward.

[0023] As shown in Figures 4 and 7, the lower inclined edge portions 54b, 55b have folding guide portions 54b-1, 55b-1 that guide the folding of the side gusset film 50 when the content liquid is filled into the content liquid storage portion 21, and lower end connecting portions 54b-2, 55b-2 that connect the lower ends of the folding guide portions 54b-1, 55b-1 to the lower end connecting portion 53a.

[0024] The folding guide portions 54b-1, 55b-1 are portions that guide the folding of the side gusset films 50 when the content liquid accommodating portion 21 is filled with the content liquid, that is, when the pouch body 20 is inflated so that the front film 30 and the back film 40 are separated in the front-back direction X. These folding guide portions 54b-1, 55b-1 guide the side gusset films 50 to bend along the imaginary folding line L2 defined by the folding guide portions 54b-1, 55b-1 when the content liquid accommodating portion 21 is filled with the content liquid and the pouch body 20 is inflated.

[0025] In this embodiment, as shown in Figures 4 and 7, the bending guide portions 54b-1, 55b-1 are formed continuously with the lower ends of the base edges 54a, 55a, and are formed as straight portions that are inclined (at an inclination angle of 45° in this embodiment) so as to approach the central virtual line L1 side (i.e., the central virtual line L1 side that extends linearly in the up-down direction Y through the lower end connecting portion 53a and the upper end connecting portion 53b from the center in the front-to-back direction X of the side gusset film 50). In this way, when the bending guide portions 54b-1, 55b-1 are formed as straight portions, the bending virtual line L2 becomes a virtual line that extends from the bending guide portions 54b-1, 55b-1, as shown in Figures 4 and 7. Here, when the folding guide portions 54b-1, 55b-1 are formed as straight portions, in order to properly guide the folding of the side gusset film 50, it is preferable to form the folding guide portions 54b-1, 55b-1 so that the width dimension W1 of the folding guide portions 54b-1, 55b-1 in the front-to-back direction X is 20% or more of the width dimension W from the central virtual line L1 to the base edge portions 54a, 55a in the front-to-back direction X, as shown in Figures 4 and 7.

[0026] The specific form of the folding guide portions 54b-1, 55b-1 is not limited to those formed as straight portions, and may be any form capable of guiding the folding of the side gusset film 50, such as those formed as convex curved portions toward the central virtual line L1. In the present embodiment, the folding guide portions 54b-1, 55b-1 are formed continuously with the lower ends of the base edges 54a, 55a, but other portions (consisting of curved or straight portions) may be interposed between the base edges 54a, 55a and the folding guide portions 54b-1, 55b-1.

[0027] As shown in Figures 4 and 7, the lower end connection portions 54b-2, 55b-2 are portions that connect the lower ends of the bending induction portions 54b-1, 55b-1 to the lower end connecting portion 53a, and connect the lower ends of the bending induction portions 54b-1, 55b-1 to the lower end connecting portion 53a so that the lower end connecting portion 53a is positioned lower than the first virtual intersection P1 where the central virtual line L1 and the bending virtual line L2 intersect.

[0028] In this embodiment, as shown in FIGS. 4 and 7, the lower end connection portions 54b-2, 55b-2 are formed as convex curved portions toward the central imaginary line L1 (inward in the front-to-back direction X) to smoothly connect the lower ends of the bend guide portions 54b-1, 55b-1 and the lower end connecting portion 53a (i.e., to avoid corners at the connection points between the bend guide portions 54b-1, 55b-1). By forming the lower end connection portions 54b-2, 55b-2 as convex curved portions, the load from the contents can be effectively borne by the lower end connection portions 54b-2, 55b-2 while preventing the load from concentrating at a specific point on the lower inclined edge portions 54b, 55b. Furthermore, as shown in FIGS. 4 and 7, the entire lower end connection portions 54b-2, 55b-2 are positioned outside the bend guide portion L2 in the front-to-back direction X.

[0029] In this embodiment, the lower end connection portions 54b-2, 55b-2 are formed as convex curved portions as described above, but the specific form of the lower end connection portions 54b-2, 55b-2 is not limited to this and may be any form, such as a straight portion, or a combination of one or more straight portions or one or more curved portions.

[0030] As shown in FIGS. 3 and 6, the upper inclined edges 54c, 55c are portions that extend generally inclined in the up-down direction Y so as to move inward in the front-to-back direction X as they extend upward.

[0031] As shown in Figures 5 and 8, the upper inclined edge portions 54c, 55c have folding guide portions 54c-1, 55c-1 that guide the folding of the side gusset film 50 when the content liquid is filled into the content liquid storage portion 21, and upper end connection portions 54c-2, 55c-2 that connect the upper ends of the folding guide portions 54c-1, 55c-1 to the upper end connection portion 53b.

[0032] The folding guide portions 54c-1, 55c-1 are portions that guide the folding of the side gusset films 50 when the content liquid accommodating portion 21 is filled with the content liquid, that is, when the pouch body 20 is inflated so that the front film 30 and the back film 40 are separated in the front-back direction X. These folding guide portions 54c-1, 55c-1 guide the side gusset films 50 to bend along the imaginary folding line L3 defined by the folding guide portions 54c-1, 55c-1 when the content liquid accommodating portion 21 is filled with the content liquid and the pouch body 20 is inflated.

[0033] In this embodiment, the bend guide portions 54c-1, 55c-1 are formed continuously with the upper ends of the base edges 54a, 55a, and are formed as straight portions that are inclined (at an inclination angle of 45° in this embodiment) so as to move upward toward the central virtual line L1 (inward in the front-to-back direction X), as shown in Figures 5 and 8. When the bend guide portions 54c-1, 55c-1 are formed as straight portions in this way, the bend virtual line L3 becomes a virtual line that extends from the bend guide portions 54c-1, 55c-1, as shown in Figures 5 and 8. Here, when the folding guide portions 54c-1, 55c-1 are formed as straight portions, in order to properly guide the folding of the side gusset film 50, it is preferable to form the folding guide portions 54c-1, 55c-1 so that the width dimension W2 of the folding guide portions 54c-1, 55c-1 in the front-to-back direction X is 20% or more of the width dimension W from the central virtual line L1 to the base edge portions 54a, 55a in the front-to-back direction X, as shown in Figures 5 and 8.

[0034] The specific form of the folding guide portions 54c-1, 55c-1 is not limited to those formed as straight portions, and may be any form capable of guiding the folding of the side gusset film 50, such as those formed as convex curved portions toward the central virtual line L1. In the present embodiment, the folding guide portions 54c-1, 55c-1 are formed continuously with the upper ends of the base edges 54a, 55a, but other portions (consisting of curved or straight portions) may be interposed between the base edges 54a, 55a and the folding guide portions 54c-1, 55c-1.

[0035] As shown in Figures 5 and 8, the upper end connection portions 54c-2, 55c-2 are portions that connect the upper ends of the bending induction portions 54c-1, 55c-1 to the upper end connecting portion 53b, and connect the upper ends of the bending induction portions 54c-1, 55c-1 to the upper end connecting portion 53b so that the upper end connecting portion 53b is positioned above the third virtual intersection P3 where the central virtual line L1 and the bending virtual line L3 intersect.

[0036] In this embodiment, as shown in FIGS. 5 and 8, the upper end connection portions 54c-2, 55c-2 are formed as convex curved portions toward the central imaginary line L1 (inward in the front-to-back direction X) that smoothly connect the upper ends of the bend guide portions 54c-1, 55c-1 and the upper end connecting portion 53b (i.e., connect the bend guide portions 54c-1, 55c-1 so that no corners are formed at the connection points between them). By forming the upper end connection portions 54c-2, 55c-2 as convex curved portions, the load from the contents can be effectively borne by the upper end connection portions 54c-2, 55c-2 while preventing the load from concentrating at a specific point on the upper inclined edge portions 54c, 55c. Furthermore, as shown in FIGS. 5 and 8, the entire upper end connection portions 54c-2, 55c-2 are positioned outward in the front-to-back direction X from the bend guide portion L3.

[0037] In this embodiment, the upper end connection portions 54c-2, 55c-2 are formed as convex curved portions as described above, but the specific form of the upper end connection portions 54c-2, 55c-2 is not limited to this and may be any form, such as a straight portion, or a combination of one or more straight portions or one or more curved portions.

[0038] The side gusset film 50 is formed symmetrically (left-right symmetrically) with respect to the central imaginary line L1; in other words, the front outer edge 54 and the back outer edge 55 are formed symmetrically (left-right symmetrically) with respect to the central imaginary line L1.

[0039] In addition, as shown in Figures 2 and 3, one of the side gusset films 50 has a circular spout through hole 56 formed to penetrate the film thickness direction, for inserting the pouring tube portion of the spout 70.

[0040] As shown in Figures 3 and 6, the side gusset films 50 on both the left and right sides have central folded portions 57 in which the side gusset films 50 are folded (folded) in a convex shape toward the inside of the pouch along the central virtual line L1.

[0041] 1 and 2, the inner film 60 is folded in half and placed inside the pouch body 20 (content liquid storage section 21), with predetermined locations heat-sealed to the films 30 and 40. As shown in Fig. 2, the inner film 60 has a plurality of film perforations formed as holes that penetrate through the film in the thickness direction.

[0042] The spout 70 is made of a synthetic resin or the like, and is attached to the pouch body 20 to function as a spout for the liquid content. The spout 70 is attached to one of the left and right side gusset films 50 by heat welding a portion of the spout 70 (in this embodiment, the flange portion) to the side gusset film 50.

[0043] In this embodiment, as shown in Figure 3, the spout 70 is attached to the area between the base edges 54a, 55a of one of the side gusset films 50 on both the left and right sides. In other words, the spout 70 is attached to an area of ​​the side gusset film 50 other than the area between the lower inclined edge 54b of the front outer edge 54 and the lower inclined edge 55b of the back outer edge 55, and the spout 70 is attached to an area of ​​the side gusset film 50 other than the area between the upper inclined edge 54c of the front outer edge 54 and the upper inclined edge 55c of the back outer edge 55.

[0044] 1 and 2, a handle hole 26 is formed in the region where the films 30, 40, and 60 overlap (top seal 23) in the bag-making seal section on the top side of the horizontal gusset pouch 10. The handle hole 26 penetrates the region where the films 30, 40, and 60 overlap, allowing a user to hold the horizontal gusset pouch 10 with their hand or fingers. For ease of understanding the technology, FIG. 2 shows the handle hole 26 as being formed before the films 30, 40, and 60 are heat-sealed together. However, in this embodiment, the handle hole 26 is formed by punching out predetermined locations after the films 30, 40, and 60 are heat-sealed together.

[0045] 10, in this embodiment, the bottom seal 24 is formed so that its center (or near its center) in the left-right direction Z rises upward, and has a folding control seal portion 24a (the upper edge of which is located above both left and right ends 24c) (which are continuous with the left and right side seals 22). Note that in this embodiment, the width of the bottom seal 24 in the up-down direction Y is constant (or approximately constant), as shown in FIG.

[0046] The fold control seal unit 24a is intended to control the position and state at which the films 30, 40 are folded (bent) when the horizontal gusset pouch 10 is placed with the pouch bottom 20a side (bottom seal 24 side) facing downwards, as shown in Fig. 1. That is, when the horizontal gusset pouch 10 is placed as shown in Fig. 1, the lower portion of the horizontal gusset pouch 10 including the bottom seal 24 (portion B shown in Figs. 1 and 10) is folded at the pouch bottom 20a toward either the front side or the back side in the front-back direction X, and at this time, the fold control seal unit 24a controls the position and state at which the films 30, 40 are folded (bent).

[0047] As shown in FIG. 10, the uppermost portion of the upper edge of the folding control seal portion 24a extends linearly in the left-right direction Z.

[0048] As shown in Figure 10, the folding control seal portion 24a is formed near the pouch bottom 20a such that, when the horizontal gusset pouch 10 is folded so that the inner surfaces of the front film 30 and the back film 40 are in contact with each other (in the example shown in Figure 10, the side gusset films 50 on both the left and right sides are folded in half at the central virtual line L1), the uppermost portion of the upper edge of the folding control seal portion 24a (the portion extending linearly along the left-right direction Z as described above) is in contact with the sixth virtual line L6 connecting the first virtual intersection points P1 on both the left and right sides in the left-right direction.

[0049] In this embodiment, as shown in FIG. 10, a lower unsealed portion 24b to which the films 30, 40 are not heat-sealed is formed below (outside of) the folding control sealed portion 24a.

[0050] In the horizontal gusset pouch 10 of the present embodiment obtained in this manner, the lower end connecting portions 54b-2, 55b-2 are formed so that the lower end connecting portion 53a is located below the first imaginary intersection P1 where the central imaginary line L1 and the bending imaginary line L2 intersect, as shown in Figures 4 and 7. This prevents delamination (i.e., peeling between the heat-sealed films 30, 40, 50) from occurring near the lower end connecting portion 53a even when pressure is applied to the horizontal gusset pouches 10 filled with the liquid content, such as when multiple horizontal gusset pouches 10 filled with the liquid content are stacked together, and prevents leakage of the liquid content due to such delamination.

[0051] That is, when the liquid content storage section 21 is filled with the liquid content and the pouch body 20 is inflated, most of the side gusset films 50 (portions other than regions R1 and R2, which will be described later) move toward the outside of the pouch as the pouch body 20 inflates. However, in the horizontal gusset-type pouch 10 of this embodiment, as shown in FIGS. 4 and 7, the lower end connecting portions 54b-2 and 55b-2 are formed so that the lower end connecting portion 53a is located below the first virtual intersection P1 (i.e., outside the virtual bending line L2). Even when the liquid content storage section 21 is filled with the liquid content and the pouch body 20 is inflated, the region R1 of the side gusset film 50 near the lower end connecting portion 53a, which is located outside (below) the imaginary bending line L2, is prevented from moving outward as the pouch body 20 inflates (in other words, the region R1 remains located in a recessed position), so that the load caused by the pressure is prevented from being concentrated on the lower end connecting portion 53a, and the occurrence of delamination near the lower end connecting portion 53a can be suppressed.

[0052] Furthermore, the region R1 of the above-mentioned side gusset film 50 is a portion that is bent so as to form a convex shape toward the inside of the pouch near the central virtual line L1, and if the film state were to change so that such region R1 becomes convex toward the outside of the pouch as the pouch body 20 expands, a load would be placed on the vicinity of the lower end connecting portion 53a. However, in the horizontal gusset-type pouch 10 of this embodiment, as described above, it is possible to prevent region R1 of the side gusset film 50 from moving outward as the pouch body 20 expands, and in this respect, too, excessive load is prevented from being placed on the vicinity of the lower end connecting portion 53a of the side gusset film 50, thereby suppressing the occurrence of delamination near the lower end connecting portion 53a.

[0053] 5 and 8, in the horizontal gusset pouch 10 of this embodiment, the upper end connecting portions 54c-2, 55c-2 are formed so that the upper end connecting portion 53b is located above the third virtual intersection P3 where the central virtual line L1 and the bent virtual line L3 intersect. Even when pressure is applied to the horizontal gusset pouch 10 filled with the liquid content, delamination near the upper end connecting portion 53b is suppressed, and leakage of the liquid content due to delamination can be avoided.

[0054] Here, the mechanism for suppressing delamination near the upper end connecting portion 53b is the same as the mechanism for suppressing delamination near the lower end connecting portion 53a described above, and therefore a detailed description thereof will be omitted. Note that, when multiple horizontal gusset pouches 10 filled with liquid contents are stacked on top of each other with the pouches laid horizontally or with the top seal 23 facing downward, delamination may also occur near the upper end connecting portion 53b due to pressure applied near the upper end connecting portion 53b. Note that region R2 shown in Figures 5 and 8 is the region of the side gusset film 50 near the upper end connecting portion 53b, which is located outside (above) the imaginary bending line L3.

[0055] As shown in Figures 1 and 9, when the content liquid storage section 21 is filled with the content liquid and the pouch body 20 is inflated, most of the side gusset film 50 moves toward the outside of the pouch as the pouch body 20 inflates, and as can be seen from Figures 3, 6, and 9, the vicinity of the fourth imaginary line L4 between the lower ends of the base edge portions 54a, 55a of the side gusset film 50 and the fifth imaginary line L5 between the upper ends thereof are bent convexly toward the outside of the pouch.

[0056] 1 and 9, the region of the side gusset film 50 between the lower inclined edges 54b, 55b constitutes the pouch bottom 20a that is placed on the placement surface when the horizontal gusset pouch 10 is used or displayed with the content liquid filled in the content liquid storage section 21 and the pouch body 20 inflated. Accordingly, the lower end connecting portion 53a is located at the pouch bottom 20a.

[0057] Furthermore, in this embodiment, the bottom seal 24 has a folding control seal portion 24a located above both the left and right ends thereof, so that when the horizontal gusset pouch 10 is placed with the pouch bottom 20a side facing downwards, it is possible to stabilize the position and state in which the films 30, 40 are folded, thereby suppressing the occurrence of pinholes that tend to occur when the position and state in which the films 30, 40 are folded are unstable. That is, as shown in FIG. 11, in the case where the lower end connection portions 54b-2, 55b-2 are formed so that the lower end connecting portion 53a is positioned below the first virtual intersection P1, and the folding control seal portion 24a is not formed and the bottom seal 24 is formed in a band shape extending linearly along the left-right direction Z, as shown by line S in FIG. 11 (the lower end line S of the area where the content liquid is present), the content liquid will enter below the sixth virtual line L6 near the center in the left-right direction Z, and as a result, the films 30, 40 will not be able to be folded properly (folded along a straight line) and will become wrinkled. If the horizontal gusset-type pouch 10 is repeatedly lifted and placed in such a wrinkled state, stress will be placed on the films 30, 40, and there is a risk of holes being created in the films 30, 40, that is, so-called pinholes. In contrast to this, in the present embodiment, as shown in FIG. 10, by forming a folding control seal portion 24a in the bottom seal 24, it is possible to stabilize the position and state in which the films 30, 40 are folded, and therefore it is possible to suppress the occurrence of wrinkles in the films 30, 40 when the horizontal gusset-type pouch 10 is placed, and it is possible to prevent pinholes from occurring in the films 30, 40.

[0058] Furthermore, the folding control seal portion 24a is formed so that when the horizontal gusset-type pouch 10 is folded, the uppermost portion of the upper edge of the folding control seal portion 24a is in contact with the sixth imaginary line L6, thereby making it possible to guide the position at which the films 30, 40 are folded onto the sixth imaginary line L6 where the crease is most desired.

[0059] Furthermore, since the uppermost part of the upper edge of the folding control seal portion 24a extends in a straight line along the left-right direction, it is possible to reliably prevent the contents from entering below the sixth imaginary line L6, and the films 30, 40 can be folded smoothly along a straight line.

[0060] Furthermore, by forming lower unsealed portion 24b below folding control sealing portion 24a, it is possible to prevent the film at pouch bottom 20a from wrinkling, thereby preventing the bag from breaking due to the wrinkling. In other words, if the film were sealed up to the position of lower unsealed portion 24b, the film would become stiff and become prone to wrinkling, but by forming lower unsealed portion 24b, it is possible to prevent the occurrence of such wrinkling.

[0061] Next, in order to confirm the effectiveness of forming the lower end connection portions 54b-2, 55b-2 in preventing delamination near the lower end connecting portion 53a, the applicant conducted tests in which the ratio of the vertical distance H2 to the vertical distance H1 described below was varied.

[0062] First, as shown in Figures 4 and 7, the vertical distance H1 is the vertical distance between the second virtual intersection P2 where the bent virtual line L2 intersects with the base edge portions 54a and 55a and the first virtual intersection P1, and the vertical distance H2 is the vertical distance between the first virtual intersection P1 and the lower end connecting portion 53a.

[0063] In this test, pouches were prepared that were filled with the content liquid (water) and inflated, such that H2 / H1 = 0 (i.e., H2 = 0), H2 / H1 = 0.10, H2 / H1 = 0.14, and H2 / H1 = 0.20. After pressure was applied to each pouch containing the content liquid, the pouches were visually inspected from the outside to see if delamination had occurred near the lower end connecting portion 53a. After visual inspection, the pouches were disassembled by cutting the film or other methods to check if delamination had occurred.

[0064] In this test, pouches having the same configuration as that shown in Figure 1 were used. In this test, pouches using the following Film 1 as the front film, back film, and side gusset film constituting the pouch, and pouches using the following transparent Film 2 as the front film, back film, and side gusset film were used. Film 1: A film formed by laminating, from the outer layer side, a 12 μm thick PET, a 12 μm thick PET with an aluminum vapor-deposited layer on the outer layer side, a 15 μm thick nylon, and a 150 μm thick LLDPE (low-density polyethylene). Film 2: A film formed by laminating, from the outer layer side, a 12 μm thick PET, a 15 μm thick nylon, and a 150 μm thick LLDPE (low-density polyethylene). The number of pouches using Film 1 and the number of pouches using Film 2 used as test specimens were 16 each.

[0065] As a result, as can be seen from the test results shown below, it was found that it is preferable to form the lower end connection portions 54b-2, 55b-2 so that H2 / H1 is 0.1 or more, and it is even more preferable to form them so that H2 / H1 is 0.2 or more. Similar results were obtained for both the pouch made using the above film 1 and the pouch made using the above film 2. H2 / H1=0: × H2 / H1=0.10: ○ H2 / H1=0.14: ○ H2 / H1=0.20: ◎

[0066] Specifically, for pouches with H2 / H1 = 0, delamination was confirmed near the bottom connecting portion 53a by visual inspection from outside the pouch for some test specimens. For pouches with H2 / H1 = 0.10 and pouches with H2 / H1 = 0.14, delamination was not confirmed near the bottom connecting portion 53a by visual inspection from outside the pouch for all test specimens, and minor delamination that did not result in leakage of the contents was confirmed for some test specimens by pouch decomposition. For pouches with H2 / H1 = 0.20, delamination was not confirmed near the bottom connecting portion 53a by visual inspection from outside the pouch for all test specimens, and delamination was not confirmed for all test specimens by pouch decomposition.

[0067] 5 and 8, the vertical distance H3 is the vertical distance between the fourth virtual intersection P4 where the virtual bend line L3 intersects with the base edge portions 54a, 55a and the third virtual intersection P3, and the vertical distance H4 is the vertical distance between the third virtual intersection P3 and the upper end connecting portion 53b.

[0068] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design modifications can be made without departing from the scope of the present invention as set forth in the claims. Furthermore, the horizontal gusset-type pouch 10 may be constructed by arbitrarily combining the respective configurations of the above-described embodiments and the modified examples described below.

[0069] For example, the horizontal gusset pouch 10 may be housed in an outer case (not shown) when in use, on display, or transported, or the horizontal gusset pouch 10 itself may be used, displayed, or transported without being housed in an outer case (not shown).

[0070] As for specific embodiments of the films 30, 40, 50, and 60, any film having a heat-sealable layer made of an olefin such as low-density polyethylene or polypropylene, or a polyester such as PET (polyethylene terephthalate) on at least one side may be used as a single heat-sealable layer, or any layer may be laminated on the heat-sealable layer. Any material may be used to form the laminate, and any desired layer may be formed by laminating known materials such as polyesters such as PET or PBT (polybutylene terephthalate), polypropylene, polyamide, polyethylene, or aluminum foil.

[0071] Furthermore, in the above-described embodiment, the pouch body 20 is described as being formed from four films, i.e., films 30, 40, and 50. However, the specific aspects of the pouch body 20, such as the number of films constituting the pouch body 20, are not limited to the above. Furthermore, the inner film 60 may not be provided. Furthermore, in the above-described embodiment, the horizontal gusset pouch 10 is configured as a large-capacity pouch with a capacity of 2 to 5 L, and the spout 70 is configured as a large spout with an outer diameter of the flange 81 of 50 to 70 mm. However, the sizes of the horizontal gusset pouch 10 and the spout 70 are not limited thereto and may be set as desired depending on the embodiment. Furthermore, in the above-described embodiment, the horizontal gusset pouch 10 is described as including the spout 70. However, the spout 70 may not be provided. Furthermore, when attaching the spout 70 to the side gusset film 50, the above-described embodiment describes the spout 70 being attached to the area between the base edge portions 54a, 55a, but the attachment position of the spout 70 is not limited to the above, and for example, at least a portion of the spout 70 may be attached to the area between the upper inclined edge portions 54c, 55c.

[0072] In addition, in the above-described embodiment, the front outer edge 54 and the back outer edge 55 are described as being formed in line symmetry (bilateral symmetry) with respect to the central virtual line L1, but the front outer edge 54 and the back outer edge 55 may also be formed asymmetrically.

[0073] In addition, in the above-described embodiment, it has been described that the bending guide portions 54b-1, 55b-1 and the lower end connection portions 54b-2, 55b-2 are formed on the lower inclined edge portions 54b, 55b of both the left and right side gusset films 50, but it is also possible to form the bending guide portions 54b-1, 55b-1 and the lower end connection portions 54b-2, 55b-2 on the lower inclined edge portions 54b, 55b of only one of the left and right side gusset films 50.

[0074] In addition, in the above-described embodiment, it has been described that the bending guide portions 54c-1, 55c-1 and the upper end connection portions 54c-2, 55c-2 are formed on the upper inclined edge portions 54c, 55c in both the left and right side gusset films 50, but it is not necessary to form the bending guide portions 54c-1, 55c-1 and the upper end connection portions 54c-2, 55c-2 in both the left and right side gusset films 50, and it is also possible to form the bending guide portions 54c-1, 55c-1 and the upper end connection portions 54c-2, 55c-2 in only one of the left and right side gusset films 50.

[0075] Furthermore, in the above-described embodiment, it has been described that the side gusset film 50 has a central fold processing portion 57 formed therein, but it is not necessary to form the central fold processing portion 57 (in at least one of the side gusset films 50), that is, it is not necessary to perform folding processing on the side gusset film 50.

[0076] In addition, in the above-described embodiment, it has been explained that the shape of the outer edges 54, 55 and the width dimension W are the same between the left and right side gusset films 50, but the shape of the outer edges 54, 55 and the width dimension W may be different between the left and right side gusset films 50.

[0077] In addition, in the above-described embodiment, the folding control seal portion 24a is described as being formed continuously with the base of the bottom seal 24 (continuous with the side seals 22 on both the left and right sides), but as shown in Figure 12, the folding control seal portion 24a may also be formed as part of the bottom seal 24 and provided independently (separately, in other words, in the form of a point seal) from the base 24d of the bottom seal 24.

[0078] In this specification, terms indicating top and bottom, such as "top," "bottom," and "side," are used, but these terms do not limit the orientation of the horizontal gusset pouch 10 when it is displayed or transported. For example, when it is displayed or transported, the horizontal gusset pouch 10 may be placed on a supporting surface with the side or top of the horizontal gusset pouch 10 facing downwards.

[0079] Some or all of the above-described embodiments may be described as, but are not limited to, the following supplementary notes: (Supplementary Note 1) A horizontally gusseted pouch comprising a front film, a back film, and side gusset films on both the left and right sides arranged between the front and back films and heat-sealed to the front and back films by side seals, wherein the side gusset films have a front-side sealed area heat-sealed to the front film at the side seals, a back-side sealed area heat-sealed to the back film at the side seals, and a non-sealed area that is an area inside the front-side sealed area and the back-side sealed area, and the non-sealed area has a front-side outer edge that is a boundary with the front-side sealed area and a back-side outer edge that is a boundary with the back-side sealed area, The front outer edge and the back outer edge each have a base edge portion arranged spaced apart from each other in the front-to-back direction, an upper inclined edge portion extending from the upper end of the base edge portion to an upper end connecting portion that connects the upper ends of the front outer edge and the back outer edge, and a lower inclined edge portion extending from the lower end of the base edge portion to a lower end connecting portion that connects the lower ends of the front outer edge and the back outer edge, and at least one of the side gusset films on both the left and right sides has a folding guide portion that guides the folding of the side gusset film when the content liquid is filled into the content liquid storage portion, and a lower end connecting portion that connects the lower end of the folding guide portion and the lower end connecting portion, A horizontal gusset pouch, characterized in that the lower end connection portion connects the lower end of the fold guide portion and the lower end connection portion so that the lower end connection portion is located lower than a first virtual intersection point where a central virtual line passing through the upper end connection portion and the lower end connection portion intersects with a virtual fold line defined by the fold guide portion. (Appendix 2) The horizontal gusset pouch according to Appendix 1, characterized in that the fold guide portion is formed as a straight portion that slopes downward so as to approach the central virtual line. (Appendix 3) The horizontal gusset pouch according to Appendix 1 or Appendix 2, characterized in that the fold guide portion is formed continuously with the lower end of the base edge portion.(Appendix 4) The horizontal gusset pouch according to any one of Appendices 1 to 3, characterized in that the lower end connection portion is formed as a curved portion that is convex toward the central virtual line. (Appendix 5) The horizontal gusset pouch according to any one of Appendices 1 to 4, characterized in that, when the vertical distance between the first virtual intersection and a second virtual intersection point where the virtual bend line and the base edge intersect is defined as H1, and the vertical distance between the first virtual intersection point and the lower end connecting portion is defined as H2, the lower end connection portion is formed so that H2 / H1 is 0.1 or more. (Appendix 6) The horizontal gusset pouch according to any one of Appendices 1 to 5, characterized in that the side gusset film has a central folded portion that is folded convexly toward the inside of the pouch along the central virtual line. (Appendix 7) The horizontal gusset pouch according to any one of Appendices 1 to 6, further comprising a spout attached to the side gusset film, the spout being attached to an area of ​​the side gusset film other than an area between the lower inclined edge portion of the front outer edge and the lower inclined edge portion of the back outer edge. (Appendix 8) The horizontal gusset pouch according to any one of Appendices 1 to 7, characterized in that the lower end connecting portion is a portion located at the bottom of the pouch when the content liquid accommodating portion is filled with content liquid and the pouch body is inflated. (Appendix 9) The horizontal gusset pouch according to any one of Appendices 1 to 8, further comprising a bottom seal formed continuously with the side seals on both the left and right sides at the bottom of the pouch, the bottom seal having a fold-control seal portion located above both the left and right ends of the bottom seal. (Appendix 10) The horizontal gusset pouch according to Appendix 9, characterized in that both of the side gusset films on both the left and right sides have the lower end connection portion, and the folding control seal portion is formed so that, when the horizontal gusset pouch is folded so that the inner surfaces of the front film and the back film are in contact with each other, the uppermost part of the upper edge of the folding control seal portion is in contact with an imaginary line connecting the first imaginary intersection points on both the left and right sides in the left-right direction.(Supplementary Note 11) The horizontal gusset pouch according to Supplementary Note 9 or Supplementary Note 10, wherein the folding-control seal portion has an uppermost portion extending linearly in the left-right direction at its upper edge. (Supplementary Note 12) The horizontal gusset pouch according to any one of Supplementary Notes 9 to 11, wherein a lower unsealed portion is formed below the folding-control seal portion. (Appendix 13) A horizontal gusset pouch comprising a front film, a back film, and side gusset films on both left and right sides disposed between the front film and the back film and heat-sealed to the front film and the back film by side seals, wherein the side gusset films have a front-side sealed area heat-sealed to the front film at the side seals, a back-side sealed area heat-sealed to the back film at the side seals, and a non-sealed area which is an area inside the front-side sealed area and the back-side sealed area, and the non-sealed area has a front-side outer edge which is a boundary with the front-side sealed area and a back-side outer edge which is a boundary with the back-side sealed area, The front outer edge and the back outer edge each have a base edge portion arranged spaced apart from each other in the front-to-back direction, an upper inclined edge portion extending from the upper end of the base edge portion to an upper end connecting portion that connects the upper ends of the front outer edge and the back outer edge, and a lower inclined edge portion extending from the lower end of the base edge portion to a lower end connecting portion that connects the lower ends of the front outer edge and the back outer edge, and at least one of the side gusset films on both the left and right sides has a folding guide portion that guides the folding of the side gusset film when the content liquid is filled into the content liquid storage portion, and an upper end connecting portion that connects the upper end of the folding guide portion and the upper end connecting portion, a third virtual intersection point where a central virtual line passing through the upper end connecting portion and the lower end connecting portion intersects with a virtual bending line defined by the bending guide portion;

[0080] DESCRIPTION OF SYMBOLS 10 Horizontal gusset pouch 20 Pouch body 20a Pouch bottom 21 Content liquid storage section 22 Side seal 23 Top seal 24 Bottom seal 24a Folding control seal section 24b Lower unsealed section 24c Left and right end sections 25 Middle seal 26 Handle hole 30 Front film 40 Back film 50 Side gusset film 51 Front sealed area 52 Back sealed area 53 Non-sealed area 53a Lower end connecting section 53b Upper end connecting section 54 Front outer edge 54a Base edge 54b Lower inclined edge 54b-1 Bend guide section 54b-2 Lower end connecting section 54c ...Upper inclined edge 54c-1 ...Bending guide portion 54c-2 ...Upper end connection portion 55 ...Back outer edge 55a ...Base edge portion 55b ...Lower inclined edge 55b-1 ...Bending guide portion 55b-2 ...Lower end connection portion 55c ...Upper inclined edge 55c-1 ...Bending guide portion 55c-2 ...Upper end connection portion 56 ...Spout through hole 57 ...Central folding portion 60 ...Inner film 70 ...Spout L1 ...Central virtual line L2 ...Bending virtual line L3 ...Bending virtual line L4 ...Fourth virtual line L5 ...Fifth virtual line L6 ...Sixth virtual line P1 ...First virtual intersection P2 ...Second virtual intersection P3 ...Third virtual intersection P4 ...Fourth virtual intersection X ...Front-rear direction Y ...Up-down direction Z ...Left-right direction

Claims

1. A horizontal gusset pouch comprising a front film, a back film, and side gusset films on both the left and right sides that are disposed between the front and back films and are heat-sealed to the front and back films by side seals, wherein the side gusset films have a front-side sealed area that is heat-sealed to the front film at the side seals, a back-side sealed area that is heat-sealed to the back film at the side seals, and a non-sealed area that is an area inside the front-side sealed area and the back-side sealed area, and the non-sealed area has a front-side outer edge that is a boundary with the front-side sealed area and a back-side outer edge that is a boundary with the back-side sealed area, The front outer edge and the back outer edge each have a base edge portion arranged spaced apart from each other in the front-to-back direction, an upper inclined edge portion extending from the upper end of the base edge portion to an upper end connecting portion that connects the upper ends of the front outer edge and the back outer edge, and a lower inclined edge portion extending from the lower end of the base edge portion to a lower end connecting portion that connects the lower ends of the front outer edge and the back outer edge, and at least one of the side gusset films on both the left and right sides has a folding guide portion that guides the folding of the side gusset film when the content liquid is filled into the content liquid storage portion, and a lower end connecting portion that connects the lower end of the folding guide portion and the lower end connecting portion, a lower end connecting portion connecting the lower end of the fold guide portion to the lower end connecting portion so that the lower end connecting portion is positioned lower than a first virtual intersection point where a central virtual line passing through the upper end connecting portion and the lower end connecting portion intersects with a virtual fold line defined by the fold guide portion.

2. A horizontal gusset pouch according to claim 1, characterized in that the folding guide portion is formed as a linear portion that is inclined downward so as to approach the central imaginary line.

3. The horizontal gusset pouch according to claim 1, wherein the folding guide portion is formed continuously with the lower end of the base edge portion.

4. A horizontal gusset pouch according to claim 1, characterized in that the lower end connection portion is formed as a convex curved portion toward the central imaginary line.

5. The horizontal gusset pouch according to claim 1, characterized in that, when the vertical distance between the second virtual intersection where the bent virtual line and the base edge intersect and the first virtual intersection is defined as H1, and the vertical distance between the first virtual intersection and the lower end connecting portion is defined as H2, the lower end connecting portion is formed so that H2 / H1 is 0.1 or more.

6. A horizontal gusset pouch as described in claim 1, characterized in that the side gusset film has a central folded portion in which the side gusset film is folded convexly toward the inside of the pouch along the central imaginary line.

7. A horizontal gusset pouch as described in claim 1, further comprising a spout attached to the side gusset film, the spout being attached to an area of ​​the side gusset film other than the area between the lower inclined edge of the front outer edge and the lower inclined edge of the back outer edge.

8. A horizontal gusset-type pouch as described in claim 1, characterized in that the lower end connecting portion is a portion located at the bottom of the pouch when the liquid content storage portion is filled with the liquid content and the pouch body is inflated.

9. The horizontal gusset pouch according to claim 1, further comprising a bottom seal formed contiguous with the side seals on both the left and right sides of the bottom of the pouch, the bottom seal having a fold control seal portion located above both the left and right ends.

10. The horizontal gusset pouch according to claim 9, characterized in that both of the side gusset films on the left and right sides have the lower end connection portion, and the folding control seal portion is formed so that, when the horizontal gusset pouch is folded so that the inner surfaces of the front film and the back film are in contact with each other, the uppermost part of the upper edge of the folding control seal portion is in contact with an imaginary line connecting the first imaginary intersection points on the left and right sides in the left-right direction.

11. A horizontal gusset pouch as described in claim 9, characterized in that the uppermost portion of the upper edge of the folding control seal portion extends linearly in the left-right direction.

12. The horizontal gusset pouch according to claim 9, wherein a lower unsealed portion is formed below the folding control seal portion.

13. A horizontal gusset pouch comprising a front film, a back film, and side gusset films on both the left and right sides disposed between the front and back films and heat-sealed to the front and back films by side seals, wherein the side gusset films have a front-side sealed area heat-sealed to the front film at the side seals, a back-side sealed area heat-sealed to the back film at the side seals, and a non-sealed area which is an area inside the front-side sealed area and the back-side sealed area, and the non-sealed area has a front-side outer edge which is a boundary with the front-side sealed area and a back-side outer edge which is a boundary with the back-side sealed area, The front outer edge and the back outer edge each have a base edge portion arranged spaced apart from each other in the front-to-back direction, an upper inclined edge portion extending from the upper end of the base edge portion to an upper end connecting portion that connects the upper ends of the front outer edge and the back outer edge, and a lower inclined edge portion extending from the lower end of the base edge portion to a lower end connecting portion that connects the lower ends of the front outer edge and the back outer edge, and at least one of the side gusset films on both the left and right sides has a folding guide portion that guides the folding of the side gusset film when the content liquid is filled into the content liquid storage portion, and an upper end connecting portion that connects the upper end of the folding guide portion and the upper end connecting portion, a third virtual intersection point where a central virtual line passing through the upper end connecting portion and the lower end connecting portion intersects with a virtual bending line defined by the bending guide portion;

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