JP3292497B2 - Self-standing bag and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-standing bag, and more particularly to a self-standing bag in which the bottom portion is widened in the form of a product containing contents so that the packaging bag itself can be self-standing.

[0002]

2. Description of the Related Art Conventionally, a typical example of a standing bag made of a plastic film is a gusset bag, and there is also a method of processing a bottom material. It is common to attach the bottom material to the bottom as shown in FIG. A conventional bag 100 shown in FIG. 11 includes a bag body 110 and a folded bottom material sheet 120.
0 is formed in an arc shape, and a portion where the seam 111 of the two sheet portions forming the bag body 110 and the fused portion 121 are joined has two points Q and Q (hereinafter, referred to as “Q”). (Hereinafter simply referred to as fixed points Q, Q).

[0003]

As described above, the fixed points Q,
When the bag has Q, there is a problem that stress is concentrated on the fixing points Q and Q when the bag is dropped, and the bag is easily broken from this portion. In order to avoid this problem, a thin film with high toughness may be used as a bag material.
The stiffness of the film becomes too weak, impairing the essential function of container self-reliability.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a self-contained bag which is excellent in impact resistance against dropping and the like, and which is excellent in the function which should be originally required, that is, the self-sustainability of the container. It is to provide a manufacturing method thereof.

[0005]

SUMMARY OF THE INVENTION In order to solve such a problem, the present invention is directed to a bag which is folded inward in a fold-like manner with a pair of opposed flat portions constituting the front side and the rear side of the bag. A self-supporting bag comprising: a cylindrical bag main body having two side surfaces formed so as to have folding lines; and a bottom forming sheet for sealing one opening of the bag main body, wherein the bag is The main body has two sides to open the one mouth once .
An arbitrary point on the folding line is set as a base point, and the mouth is connected from the base point.
Fold the first fold line to the edge in the opposite direction of the original
Bend it out and pull it out from the four corners of the bag body.
The line connecting the points is defined as a ridgeline that protrudes inward of the bag.
It has an open surface formed so as to be folded , and a square bottom forming sheet is formed on the open surface so as to be fused so as to form a heat seal portion on a peripheral edge thereof.

Further, the method of manufacturing a self-standing bag according to the present invention is formed so as to include a pair of opposing flat portions forming the front side and the rear side of the bag, and a folding line folded inward in a fold shape. A self-standing bag comprising: a cylindrical bag main body having two side surfaces; and a bottom forming sheet that seals one mouth of the bag main body. In order to open the one mouth, the arbitrary point of each of the fold lines on the two side surfaces is used as a base point, and the first fold line from the base point to the end of the mouth is bent in the opposite direction to the original folding direction. A step of forming an open surface in which the inside of the bag is exposed by folding a line connecting the four corners of the bag body to the base point as a ridgeline that is convex in the bag inward direction, and on the open surface, A step of placing a square bottom forming sheet, and a step of placing the placed bottom forming sheet. The edge is configured as a step of heat sealing. Further, in the above self-standing bag, the opening surface
Is bent so that it is formed in substantially the same plane.
Heat seal the edge of the surface and the edge of the square bottom forming sheet.
It is configured to be configured by

[0007]

According to the present invention, a bag body is once formed by a generally used method, and a folding line on two side surfaces is bent out of the opening end of the bag body in a direction opposite to the original folding direction and pulled out. At the same time, two open surfaces on which the inner surface of the bag is exposed are formed, a square bottom forming sheet is placed on the open surface, and the entire periphery of the sheet is heat-sealed. Unlike the conventional bag, there is no stress concentration portion, so that the bag has excellent impact resistance against dropping and the like, and also has excellent container autonomy.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 9, a self-standing bag 1 according to the present invention has a pair of opposed flat portions 1 forming the front and rear sides of the bag.
1, 11 and a fold line 2 folded inward in a fold shape
Two side surfaces 21 and 2 formed to include
1 and a cylindrical bag body 10
And a bottom forming sheet 30 for sealing one of the mouths 10a.

The bag body 10 is provided with the one mouth 10
has an open surface formed by bending the two side fold lines outwardly from the open end to open once in a direction opposite to the original fold direction, and on the open surface A square bottom forming sheet is fused so as to form a heat seal portion 30a over the entire periphery. Note that the self-standing bag shown in FIG. 9 still has room to open to the extent that the folding lines 23 and 23 disappear, and the bag shown in FIG. 9 is not completely opened yet. Such a self-standing bag 1 of the present invention
Will become clearer by describing the following manufacturing steps.

First, as shown in FIG. 1, a pair of opposing flat portions 11, 11 constituting the front side and the rear side of the bag, and fold lines 23, 23 folded inward in a folded manner are provided. A cylindrical bag main body 10 having two side surfaces 21 and 21 formed in the shape is prepared. This cylindrical bag body 10 is
Usually, it is formed by using a so-called palm joint method using a packaging material of the same material, but may be attached by laminating as described later.

Next, as shown in FIG. 2, the positions of the four corners of the mouth end of the bag body 10, ie, the bag body 10
Cuts inward from the upper end of the joint between the plane portions 11 and 11 and the side surfaces 21 and 21 to a predetermined distance, respectively.
Insert 15,15,15. These cuts have substantially the same depth. This cutting is particularly effective for facilitating the bag making operation and for adjusting the product shape by the cutting operation described later.

Next, as shown in FIG. 3, the folding lines 2 on the two side surfaces 21 and 21 are opened to open the mouth of the bag body.
3 and 23, each of which is a base point, a fold line 23 from the base point P, P to the end H, H of the fold line.
23 is folded in the reverse direction of the original fold line,
Fold it out while pulling it out to become 3a, 23a. By this folding, the four corners of the bag body (in this case, since the cuts 15, 15, 15, 15 are formed at the four corners, the four end portions D of the cuts) are necessarily taken from the base points P, P
Are formed as four ridge lines 17 protruding inside the bag (FIG. 4). At this time, open surfaces 11a, 11a, 21a, 21a in which the inside of the bag is exposed are formed.
In this embodiment, the base point P is determined such that the length of the line segment GH shown in FIG. 4 is the same as the length of the folding length L1. In the present embodiment, the opening surface is not formed in a completely opened shape due to a combination with a bottom forming sheet 30 described later, and has a constant folding angle θ1 within 180 degrees.
Is kept. However, in some cases the open face 1
Open completely so that 1a and 11a are substantially coplanar.
That it is also possible.

Such open surfaces 11a, 11a, 21
a, at the position above 21a, as shown in FIG.
A square bottom forming sheet 30 having a folding line 30a in the center is conveyed. The fold line 31 forms a fold angle θ2, which is approximately the same as the fold angle θ1 of the bag body. In the present embodiment, the size of the bottom forming sheet 30 is the open surface 11.
The size may be approximately the same as the size formed by the four edges a and 11a, or may be larger than the size formed by the four edges.

Next, as shown in FIG. 6, a square bottom forming sheet 30 is placed so that the four corners of the sheet 30 and the four edges of the open surfaces 11a, 11a substantially coincide with each other. This corresponds to the folding line 31 of the bottom forming sheet 30,
This can be easily achieved by aligning the mouth ends H of the bag body 10 with the straight line K connecting the ends H. Next, as shown in FIG. 7, folding is performed around the base line K so as to close the open surface. Thereafter, a hot plate is pressed so that the entire peripheral edge of the placed bottom forming sheet 30 is heat-sealed (a hatched portion in the drawing). In this case,
Side heat sealing of the bag body is performed. Thereafter, the tabs 29, 29 protruding from both sides of the bag body are cut off along the longitudinal ends of the bag body, and the protruding portion 28 on the bottom side of the bag body is cut along the line F in the horizontal direction. Cut in the direction to complete the self-standing bag (FIG. 8). FIG. 9 shows a state in which the self-standing bag formed in this manner is inverted, and the inside is expanded to be self-standing.

[0015] When receiving the contents into a self-standing bag formed in this way is usually contents are filled from the opening of the bag in an open state. Thereafter, the opening is fusion-sealed or a pouring member is provided. Further, the opening may be left as it is, if necessary, or may be used as a mere bag as shown in FIG. 9 without the attachment of a fusion seal or a pouring member.

The cylindrical bag body as shown in FIG. 1 is made up of flat sheets 51, 51 as shown in FIG.
And two side sheets 71, 71 formed so as to have fold lines 73, 73 folded inward in a fold shape, and may be formed so as to face each other. In this case, for example, the flat sheet 51 and the side sheet 7
The material with the material No. 1 can be appropriately changed.

[0017]

According to the present invention, the bag body is once formed by a generally used method, and the bag body is formed from the open end of the bag body.
The fold line on one side is folded in the opposite direction to the original fold direction and pulled out, and two open surfaces with the inner surface of the bag exposed are formed. A square bottom sheet is heat-sealed on the open surface. As a result, there is no stress concentration portion unlike a conventional bag, so that the bag has excellent impact resistance against dropping and the like, and also has excellent container autonomy.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a step in a process of manufacturing a self-standing bag of the present invention.

FIG. 2 is a schematic perspective view showing a step in a process of manufacturing the self-standing bag of the present invention.

FIG. 3 is a schematic perspective view showing a step in a process of manufacturing the self-standing bag of the present invention.

FIG. 4 is a schematic perspective view showing a step in a process of manufacturing the self-standing bag of the present invention.

FIG. 5 is a schematic perspective view showing a step in the process of manufacturing the self-standing bag of the present invention.

FIG. 6 is a schematic perspective view showing a step in a manufacturing process of the self-standing bag of the present invention.

FIG. 7 is a schematic perspective view showing a step in a process of manufacturing the self-standing bag of the present invention.

FIG. 8 is a schematic perspective view showing a step in the process of manufacturing the self-standing bag of the present invention.

FIG. 9 is a schematic perspective view showing a state in which the inside of the self-standing bag of the present invention is expanded to be self-standing.

FIG. 10 is a schematic perspective view showing one mode of manufacturing the bag body.

FIG. 11 is a schematic perspective view showing an example of a conventional self-standing bag.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Bag body part 11 ... Plane part 21 ... Side surface 30 ... Bottom part forming sheet

Claims (3)

(57) [Claims] 1. A cylindrical shape having a pair of opposed flat portions forming the front side and the rear side of a bag, and two side surfaces formed so as to have a folding line folded inward in a fold shape. a bag main body, a self-standing bag comprising a bottom portion forming sheet which seals one of the mouth portion of the bag body portion, said bag body portion to open once the one mouth, 2
Using any one of the folding lines on the two sides as the base point,
The first fold line from the base point to the edge of the mouth is
The bag is folded out and pulled out, and
Make a line connecting the corner to this base point convex toward the inside of the bag.
Having an open surface formed so as to be folded as a ridge line , a square bottom forming sheet is fused on the open surface so as to form a heat seal portion on a peripheral edge thereof. Self-standing bag to do. 2. A cylindrical shape having a pair of opposed flat portions forming a front side and a rear side of a bag, and two side surfaces formed so as to have fold lines inwardly folded in a fold shape. A method for manufacturing a self-supporting bag, comprising: a bag body; and a bottom forming sheet that seals one mouth of the bag body, wherein the method includes: opening the one mouth of the bag body; Using any one of the fold lines on the two side surfaces as base points, the first fold line from the base point to the end of the mouth is folded in the opposite direction to the original fold direction and folded, and from the four corners of the bag body. A step of folding a line connecting to the base point as a ridgeline protruding inward of the bag to form an open surface in which the inside of the bag is exposed; and placing a square bottom forming sheet on the open surface And heat-sealing the periphery of the placed bottom forming sheet. Method for producing a self-standing bag according to claim and. (3) The open surface is formed in substantially the same plane
Bend the edge of this open surface and the square bottom shape
It is characterized by being constructed by heat sealing with the periphery of the formed sheet
The self-standing bag according to claim 1,