JP3586457B2 - Manufacturing method of self-standing bag and self-standing bag - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a self-standing bag, particularly a self-standing bag in which a bottom portion is widened in a product form in which contents are stored and a packaging bag itself can be self-supported .
[0002]
[Prior art]
Conventionally, a typical example of a standing bag made of a plastic film is a gusset bag. In addition, there is a method of processing a bottom material, but when improving the independence of any of them, as shown in FIG. It is common to attach a bottom material to the bottom. A conventional bag 100 shown in FIG. 11 includes a bag body 110 and a folded bottom material sheet 120. A fusion part 121 between the bag body 110 and the sheet 120 is formed in an arc shape. The portion where the seam 111 of the two sheet portions to be formed and the fused portion 121 are joined is gathered at two points Q, Q (hereinafter simply referred to as fixed points Q, Q), respectively.
[0003]
[Problems to be solved by the invention]
As described above, when the bag has the fixed points Q, Q, there is a problem that stress is concentrated on the fixed points Q, Q when the bag is dropped, and the bag is easily broken from this portion. In order to avoid this problem, a thin film having high toughness may be used as the bag material. However, in the present case, the rigidity of the film becomes too weak, and the originally required function of container autonomy is impaired. .
[0004]
The present invention has been made in view of the above circumstances, and has as its object a method of manufacturing a self-standing bag which is excellent in impact resistance upon dropping and the like, and which is excellent in a function which should be originally required, that is, self-supporting of a container. Provide self-supporting bags .
[0005]
[Means for Solving the Problems]
In the present invention, in order to solve the above problem, a pair of flat portions constituting the front side and the back side of the bag, and interposed between these flat portions, the fold line is folded inward of the bag and folded. A bag body forming step of forming a bag body with a pair of side faces formed in the bag body, and after the bag body forming step, the opposing flat parts are connected to each other on one mouth side of the bag body. While opening the side portion, a section connecting the base point and a predetermined point at the four corners of the bag body forming a boundary between the flat portion and the side portion with an arbitrary point of the folding line as a base point. An open surface forming step of forming an open surface on one of the mouth sides by folding the convex portion so as to be convex inside the bag body portion, and superimposing a bottom forming member on the open surface, the bottom forming member and the bottom forming member The bottom that forms the bottom of the self-standing bag by heat-sealing them at the boundary with the bag body A part forming step, thereafter, a point on a boundary line between the flat part and the side part, and an outer dimension of the bag body in a direction in which the folding line extends from the base point; A line connecting points located at positions where the dimension in the direction perpendicular to the outer direction is the same as the base line, and cutting off an outer part in a direction in which the folding line extends from the base line . A self-standing bag manufacturing method was adopted.
In the present invention, in order to solve the above problem, a pair of flat portions constituting the front side and the back side of the bag, and a fold line interposed between the flat portions and the fold line is folded inside the bag and folded. A bag body portion forming step of forming a bag body portion with a pair of side portions formed in a fold shape, and, after the bag body portion forming step, the flat portion facing one mouth side of the bag body. Mutually open, and connects the side portion with an arbitrary point of the fold line as a base point, and connects the base point with predetermined points at four corners of the bag body forming a boundary between the flat surface portion and the side surface portion. An open surface forming step of bending the section so as to protrude inward of the bag main body to form an open surface on one of the mouth sides, and superimposing a bottom forming member on the open surface; Heat fusion at the boundary between the bag and the bag body to form the bottom of the self-standing bag A bottom portion forming step, followed by a point on a boundary line between the flat portion and the side portion, and an outer dimension of the bag body in a direction in which the folding line extends from the base point; A cutting step of cutting a portion outside the line extending in the direction in which the fold line extends from the base line with a line connecting points located at positions where the dimensions in the direction perpendicular to the fold line and the outside direction are the same. In the bag body forming step, a self-standing bag manufacturing method including a bonding step of bonding an edge of the flat portion and an edge of the side portion is adopted.
Further, a pair of flat portions constituting the front side and the back side of the bag, and a pair of side portions formed between the flat portions and formed into a fold by folding a folding line inward of the bag. And a bottom portion configured by closing one mouth of the bag body portion with a bottom forming member, wherein the bag body portion has an edge of the flat portion and the side surface. The bag body has a bonding portion formed by bonding the edge of the portion along these edges, and further, the bag body portion opens the opposing flat portions with each other with respect to one of the mouth portions. The side portion is defined as an arbitrary point of the folding line as a base point, and a section connecting the base point and predetermined points at four corners of the bag body forming a boundary between the flat portion and the side portion is defined as the bag body portion. Is bent so as to protrude inward, and an opening surface is formed on one of the mouth portions, and the bottom surface is formed. The portion is formed by superimposing a bottom forming member on the opening surface and heat-sealing them at a boundary between the bottom forming member and the bag body, and furthermore, a point on a boundary between the flat portion and the side portion. And points located at positions where the outer dimension of the bag body in the direction in which the fold line extends from the base point and the outer dimension in a direction orthogonal to the fold line are the same. Was used as a base line, and a portion outside the base line in the direction in which the fold line was extended was cut off to form a self-standing bag.
[0006]
[Action]
In the present invention, since the self-standing bag is formed by heat-sealing the boundary between the bag body and the bottom surface, the self-standing bag manufactured by this manufacturing method has no stress concentration portion. For this reason, it is excellent in impact resistance when dropped. In addition, since the boundary between the flat part and the side part, and the bag body part, the bottom part, and the boundary part are heat-sealed, respectively, the manufactured self-standing bag has excellent self-sustainability.
[0007]
【Example】
As shown in FIG. 9, the self-standing bag 1 of the present invention includes a pair of opposing flat portions 11, 11 constituting the front side and the rear side of the bag, and folding lines 23, 23 folded inward in a folded manner. A cylindrical bag main body 10 having two side surfaces 21 and 21 formed so as to have the same, and a bottom forming sheet 30 for sealing one opening 10a of the bag main body 10 are provided.
[0008]
The bag main body 10 is formed so that a folding line of two side surfaces is bent outwardly from an opening end in a direction opposite to the original folding direction in order to once open the one mouth portion 10a. A square bottom forming sheet having an opening surface is fused on the opening surface so as to form a heat-sealed 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 becomes clearer by describing the following manufacturing steps.
[0009]
First, as shown in FIG. 1, the bag is formed so as to include 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 fold shape. A cylindrical bag main body 10 having two side surfaces 21 and 21 is prepared. The tubular bag body 10 is usually 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.
[0010]
Next, as shown in FIG. 2, from the four corner positions 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. The cuts 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.
[0011]
Next, as shown in FIG. 3, in order to open the mouth of the bag body, any one point P, P of the fold lines 23, 23 of the two side surfaces 21, 21 is respectively set as a base point, and from the base points P, P The fold lines 23, 23 up to the mouth ends H, H of the fold lines are bent in the opposite direction to the original fold direction, and are folded while being drawn out so as to have the reverse fold lines 23a, 23a. By this folding, inevitably, from the four corners of the bag body (in this case, since the cuts 15, 15, 15, 15 are formed in the four corners, the four ends D of the cut) to the base points P, P The connecting lines are formed as four ridge lines 17 protruding inside the bag (FIG. 4). At this time, open surfaces 11a, 11a, 21a, 21a are formed in which the inside of the bag is exposed. In the present 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 opening surface does not have a completely opened shape due to a combination with a bottom forming sheet 30 described later, and maintains a constant folding angle θ1 within 180 degrees. However, in some cases, it is possible to completely open the opening surfaces 11a, 11a so as to be substantially coplanar.
[0012]
As shown in FIG. 5, a square bottom forming sheet 30 having a folding line 30a at the center is conveyed to a position above such open surfaces 11a, 11a, 21a, 21a. 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 set to be approximately the same as the size formed by the four edges of the open surfaces 11a, 11a, or of course, is made larger than the size formed by the four edges. You may.
[0013]
Next, as shown in FIG. 6, the 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 can be easily achieved by aligning the folding line 31 of the bottom forming sheet 30 with the straight line K connecting the mouth ends H, H of the bag body 10. Next, as shown in FIG. 7, folding is performed around the base line K so as to close the open surface. Thereafter, the hot plate is pressed so that the entire peripheral edge of the placed bottom forming sheet 30 is heat-sealed (the hatched portion in the figure). In this case, the boundary between the flat portions 11, 11 and the side surfaces 21, 21 of the bag body is usually heat-sealed. Thereafter, the tabs 29, 29 protruding from both sides of the bag body are cut off along the longitudinal end 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 way is inverted and the inside is expanded to be self-standing.
[0014]
When storing the contents in the self-standing bag thus formed, the contents are usually filled from the opening of the bag in an open state. Thereafter, the opening is fused 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 the fusion seal or the pouring member.
[0015]
The cylindrical bag main body as shown in FIG. 1 includes flat sheets 51, 51 and fold lines 73, 73 which are folded inward in a folded manner as shown in FIG. Alternatively, the two side sheets 71, 71 formed in this manner may be bonded to each other so as to face each other. In this case, for example, the materials of the flat sheet 51 and the side sheet 71 can be appropriately changed.
[0016]
【The invention's effect】
According to the self-standing bag manufacturing method and the self-standing bag according to the present invention, since the self-standing bag is formed by heat-sealing the boundary between the bag main body and the bottom portion, the self-standing bag has no stress concentration portion. For this reason, it is excellent in impact resistance when dropped. In addition, since the bag body, the bottom surface, and the boundary are thermally fused, the manufactured self-standing bag has excellent self-supporting properties.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing one step of a process of manufacturing a self-standing bag of the present invention.
FIG. 2 is a schematic perspective view showing one step of the process of manufacturing the self-standing bag of the present invention.
FIG. 3 is a schematic perspective view showing one step of the process of manufacturing the self-standing bag of the present invention.
FIG. 4 is a schematic perspective view showing one step in the process of manufacturing the self-standing bag of the present invention.
FIG. 5 is a schematic perspective view showing one step in the process of manufacturing the self-standing bag of the present invention.
FIG. 6 is a schematic perspective view showing one step of the process of manufacturing the self-standing bag of the present invention.
FIG. 7 is a schematic perspective view showing one step of the process of manufacturing the self-standing bag of the present invention.
FIG. 8 is a schematic perspective view showing one step of a process of manufacturing the self-standing bag of the present invention.
FIG. 9 is a schematic perspective view showing a state in which a self-standing bag manufactured by the manufacturing method of the present invention is expanded and self-supported.
FIG. 10 is a schematic perspective view showing one mode of manufacturing a bag body by a manufacturing method according to another embodiment of the present invention.
FIG. 11 is a schematic perspective view showing an example of a conventional self-standing bag.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Bag main-body part 11 ... Plane part 21 ... Side surface 30 ... Bottom part forming sheet

Claims (3)

The bag includes a pair of flat portions forming the front side and the rear side of the bag, and a pair of side portions formed between the flat portions and formed in a folded shape by folding a folding line inward of the bag. A bag body forming step of forming a body,
After the bag main body portion forming step, with respect to the one mouth side of the bag main body, the opposing flat surface portions are opened mutually, and the side surface portion is set at an arbitrary point of the folding line as a base point. And, a section connecting the predetermined points of the four corners of the bag body forming the boundary between the plane portion and the side surface portion is bent so as to be convex inside the bag body portion, and is opened to one of the mouth portions. Opening surface forming step of forming a surface,
A bottom portion forming step of superimposing a bottom forming member on the opening surface, and thermally fusing these at a boundary portion between the bottom forming member and the bag body to form a bottom portion of the self-standing bag,
Thereafter, a point on the boundary line between the plane portion and the side surface portion, and an outer dimension of the bag body in a direction in which the fold line extends from the base point, and a direction perpendicular to the fold line. An excision step of excision of an outer part in a direction in which the folding line extends from the base line with a line connecting points located at positions where dimensions in the outer direction are the same size,
A method for producing a self-standing bag, comprising: The bag includes a pair of flat portions forming the front side and the rear side of the bag, and a pair of side portions formed between the flat portions and formed in a folded shape by folding a folding line inward of the bag. A bag body forming step of forming a body,
After the bag main body portion forming step, with respect to the one mouth side of the bag main body, the opposing flat surface portions are opened mutually, and the side surface portion is set at an arbitrary point of the folding line as a base point. And, a section connecting the predetermined points of the four corners of the bag body forming the boundary between the plane portion and the side surface portion is bent so as to be convex inside the bag body portion, and is opened to one of the mouth portions. Opening surface forming step of forming a surface,
A bottom portion forming step of superimposing a bottom forming member on the opening surface, and thermally fusing these at a boundary portion between the bottom forming member and the bag body to form a bottom portion of the self-standing bag,
Thereafter, a point on the boundary line between the plane portion and the side surface portion, and an outer dimension of the bag body in a direction in which the fold line extends from the base point, and a direction perpendicular to the fold line. A cutting step of cutting a part outside the direction in which the fold line extends from the base line with a line connecting the points at positions where the dimensions in the outside direction are the same as the base line,
The method for producing a self-standing bag, further comprising a bonding step of bonding the edge of the flat portion and the edge of the side portion in the bag body portion forming step. Consisting of a pair of flat portions forming the front side and the back side of the bag, and a pair of side portions formed between the flat portions and folded inward with the folding line being folded inward of the bag. Bag body part,
A bottom portion configured by closing one mouth portion of the bag body portion with a bottom portion forming member,
The bag body has a bonding portion in which an edge of the plane portion and an edge of the side portion are bonded along these edges,
Further, the bag main body portion, with respect to one of the mouth portions, opens the opposing flat surface portions to each other, and sets the side surface portion to an arbitrary point of the folding line as a base point, the base point and the flat surface. A section connecting the predetermined points of the four corners of the bag body, which forms a boundary between the portion and the side surface portion, is bent so as to be convex inside the bag body portion, and an open surface is formed on one of the mouth sides. Become
The bottom portion, a bottom forming member is overlapped on the opening surface, and these are thermally fused at a boundary portion between the bottom forming member and the bag body,
In addition, a point on the boundary line between the plane portion and the side portion, and an outer dimension of the bag body in a direction in which the folding line extends from the base point, and an outer dimension in a direction orthogonal to the folding line. A self-contained bag formed by cutting a portion outside a line extending in a direction in which the fold line extends from a base line, which is a line connecting points located at positions having the same size as the direction .

Images