JP3756454B2 - Self-supporting bag - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a self-supporting bag, and more particularly to a self-supporting bag in which a bottom portion expands in a product form containing contents and the packaging bag itself can be self-supporting.
[0002]
[Prior art]
Conventionally, as a typical standing bag made of a plastic film, there is a gusset bag, and there is also a method of processing a bottom material, both of which are shown in FIG. Generally, the bottom material is fixed to the bottom. A conventional bag 100 shown in FIG. 11 includes a bag body 110 and a folded bottom material sheet 120, and a fused portion 121 of the bag body 110 and the sheet 120 is formed in an arc shape. The portions where the joints 111 and the fused portions 121 of the two sheet portions to be formed are joined together at two points Q and Q (hereinafter simply referred to as fixed points Q and Q), respectively.
[0003]
[Problems to be solved by the invention]
As described above, in the case of having the fixing points Q and Q, there is a problem that when the bag is dropped, stress concentrates on the fixing points Q and Q, and the bag breaks easily from this portion. In order to avoid this problem, a thin film with high toughness may be used as the bag material, but this time, the film becomes too weak, and the originally required function of container independence is impaired. .
[0004]
The present invention was devised in view of such circumstances, and an object thereof is to provide a self-supporting bag that is excellent in impact resistance in dropping or the like and that is excellent in a function that should be originally required, such as self-supporting property of a container. is there.
[0005]
[Means for Solving the Problems]
In the present invention, in order to solve the above-described problem, a pair of plane portions constituting the front side and the rear side of the bag, and a fold line is folded inwardly of the bag so as to be interposed between the plane portions. A self-supporting bag that has a bag main body portion formed of a pair of side surface portions and closes one mouth portion of the bag main body portion with a bottom surface portion, and the bag main body portion is a single packaging material In order to temporarily open the one mouth portion of the bag body portion, the edges of the flat portion and the side surface portion formed by bending are bonded to each other. An opening surface is formed in which the fold line of the two side surface portions is folded outwardly from the end of the mouth portion and pulled out in the direction opposite to the original folding direction, and the inner surface of the bag body portion is exposed. A self-supporting bag in which a peripheral edge of the bottom portion made of a rectangular sheet material is heat- sealed to the opening surface is adopted.
[0007]
In the present invention, the boundary portion between the flat surface portion and the side surface portion and the boundary portion between the bag main body portion and the bottom surface portion are heat- sealed, so there is no stress concentration as in conventional bags, and excellent impact resistance in dropping, etc. Moreover, it is excellent in independence.
[0008]
【Example】
As shown in FIG. 9, the self-supporting bag 1 of the present invention has a pair of opposed flat portions 11, 11 constituting the front side and the back side of the bag, and fold lines 23, 23 folded inwardly in a crease shape. The cylindrical bag main body part 10 which has the two side surfaces 21 and 21 formed so that it may be provided with, and the bottom part formation sheet 30 which seals one opening part 10a of this bag main body part 10 are provided.
[0009]
The bag body 10 is formed so as to bend and pull out the fold lines on the two side surfaces outward from the opening end in order to open the one mouth portion 10a, opposite to the original folding direction. An open surface is formed, and a rectangular bottom forming sheet is fused on the open surface so as to form a heat seal portion 30a over the entire periphery. Note that the self-supporting bag shown in FIG. 9 still has room to be opened to the extent that the fold lines 23 and 23 disappear, and the state of FIG. 9 is not completely opened as a bag. Such a self-supporting bag 1 of the present invention becomes clearer by explaining the following manufacturing process.
[0010]
First, as shown in FIG. 1, the bag is formed so as to include a pair of opposed flat portions 11, 11 constituting the front side and the rear side of the bag, and folding lines 23, 23 folded inwardly in a crease shape. A cylindrical bag body 10 having two side surfaces 21 and 21 is prepared. The cylindrical bag body 10 is usually formed by using a so-called joint-pasting method using the same packaging material, but may be performed by bonding as will be described later.
[0011]
Next, as shown in FIG. 2, the positions of the four corners of the mouth end of the bag body 10, that is, from the upper end of the boundary between the flat portions 11 and 11 and the side surfaces 21 and 21 of the bag body 10, respectively. Incisions 15, 15, 15, 15 are made inward to a predetermined distance. 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.
[0012]
Next, as shown in FIG. 3, in order to open the mouth portion of the bag body portion, any one point P, P of the fold lines 23, 23 of the two side surfaces 21, 21 is used as a base point, and from the base points P, P, respectively. The folding lines 23, 23 up to the mouth ends H, H of the folding line are folded in the opposite direction to the original folding direction, and folded while being pulled out so as to have opposite folds 23a, 23a. By this folding, inevitably, from the four corners of the bag body (in this case, since the cuts 15, 15, 15, and 15 are made at the four corners, the four end portions D of the cut) to the base points P and P. The connecting lines are formed as four ridge lines 17 that are convex inside the bag (FIG. 4). At this time, the opening surfaces 11a, 11a, 21a, and 21a where the inside of the bag is exposed are formed. In this embodiment, the base point P is determined so that the length of the line segment GH shown in FIG. 4 is the same as the length of the folding length L1. In this embodiment, the open surface is not completely opened due to the combination with the bottom forming sheet 30 described later, and maintains a constant folding angle θ1 within 180 degrees. However, in some cases, the opening surfaces 11a and 11a can be completely opened so that they are substantially on the same plane.
[0013]
As shown in FIG. 5, a rectangular bottom forming sheet 30 having a fold line 30a in the center is conveyed to positions above the open surfaces 11a, 11a, 21a, and 21a. A folding angle θ2 is formed by the folding line 31, and the folding angle θ2 is substantially the same as the folding angle θ1 of the bag body. In the present embodiment, the size of the bottom forming sheet 30 is approximately the same as the size formed by the four edges of the opening surfaces 11a and 11a, or, of course, larger than the size formed by the four edges. May be.
[0014]
Next, as shown in FIG. 6, the rectangular bottom forming sheet 30 is placed so that the four corners of the sheet 30 and the four edges of the open surfaces 11 a and 11 a substantially coincide with each other. This can be easily done by aligning the fold line 31 of the bottom forming sheet 30 with the straight line K connecting the mouth ends H of the bag body 10. Next, as shown in FIG. 7, folding is performed with the base line K as an axis so as to close the open surface. Thereafter, the hot plate is pressed so that the entire periphery of the placed bottom forming sheet 30 is heat- sealed (portion indicated by hatching in the figure). In this case, usually, the boundary between the flat portions 11 and 11 and the side surfaces 21 and 21 in the bag main body is heat-sealed . Thereafter, the tabs 29 and 29 projecting from both sides of the bag main body are cut off along the longitudinal ends of the bag main body, and the protruding portion 28 on the bottom side of the bag main body is laterally extended along the line F. Cut off in the direction to complete the self-supporting bag (FIG. 8). FIG. 9 shows a state in which the self-supporting bag formed in this way is inverted and the inside is expanded and made self-supporting.
[0015]
When the contents are stored in the self-supporting bag formed in this way, the contents are normally 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, or may be used as a simple bag as shown in FIG. 9 without the fusion seal or the attachment of the dispensing member.
[0016]
The cylindrical bag body portion as shown in FIG. 1 includes flat portion sheets 51 and 51 and folding lines 73 and 73 folded inward in a crease shape as shown in FIG. The two side sheets 71 and 71 formed in the above may be bonded together so as to face each other. In this case, for example, the material of the flat portion sheet 51 and the side sheet 71 can be appropriately changed.
[0017]
【The invention's effect】
Since the boundary between the flat part and the side part and the boundary between the bag body and bottom part are heat- sealed, there is no stress concentration unlike conventional bags, and it has excellent impact resistance when dropped, etc. Excellent in properties.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing one step of a manufacturing process of a self-supporting bag of the present invention.
FIG. 2 is a schematic perspective view showing one step in the process of manufacturing the self-supporting bag of the present invention.
FIG. 3 is a schematic perspective view showing one step of the manufacturing process of the self-supporting bag of the present invention.
FIG. 4 is a schematic perspective view showing one step in the process of manufacturing the self-supporting bag of the present invention.
FIG. 5 is a schematic perspective view showing one step in the process of manufacturing the self-supporting bag of the present invention.
FIG. 6 is a schematic perspective view showing one step in the process of manufacturing the self-supporting bag of the present invention.
FIG. 7 is a schematic perspective view showing one step in the process of manufacturing the self-supporting bag of the present invention.
FIG. 8 is a schematic perspective view showing one step of the manufacturing process of the self-supporting bag of the present invention.
FIG. 9 is a schematic perspective view showing a state in which the interior of the self-supporting bag of the present invention is unrolled and made self-supporting.
FIG. 10 is a schematic perspective view showing one aspect of manufacturing a bag body.
FIG. 11 is a schematic perspective view showing an example of a conventional self-supporting bag.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Bag main-body part 11 ... Plane part 21 ... Side surface 30 ... Bottom part formation sheet

Claims (1)

A pair of plane portions constituting the front side and the back side of the bag, and a pair of side portions interposed between the plane portions and having a fold line folded inward of the bag to form a fold shape. A self-supporting bag having a bag body portion and closing one of the mouth portions of the bag body portion with a bottom surface portion;
The bag body part is folded one sheet of packaging material, and its edges are bonded together, and the boundary part between the flat part and the side part formed by bending is heat-sealed,
In order to open the one mouth part once, the fold line of the two side face parts is folded outward from the mouth end to be bent in the direction opposite to the original folding direction and pulled out of the bag body part. An open surface with the inner surface exposed is formed ,
A self-supporting bag , wherein a peripheral edge of the bottom portion made of a rectangular sheet material separate from the bag main body portion is heat- sealed to the opening surface .

Images