JP2003237797A - Bag with flat bottom and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bag (shopping bag) with a wide and strong flat bottom. <P>SOLUTION: In the bag 11 with a flat bottom which is obtained from a flattened cylindrical element 12 having bellows 13 on both the sides thereof, the flat bottom 15 has the shape of a quadrangle (preferably a rectangle), and is formed with a bottom element 16 of a single piece which is peripherally welded to the respective lower ends of the cylindrical element 12 and the bellows 13. Under the condition that the bottom element 16 folded and assembled so as to have bellows 20 on both the sides thereof is inserted inside the cylindrical element 12, the peripheral welding is performed as a first portion 22 between the lower end of the cylindrical element 12 and each of both side parts 18 opposed to each other on one of the sides of the bottom element 16 and, as a second portion 23, between the lower end of the bellows 13 of the cylindrical element and each of the side parts (both side parts opposed to each other on the other side of the bottom element) 19 of the bellows 20 on both the sides of the bottom element. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

The present invention relates to a flat bottomed bag and a method for manufacturing the same.

In the field of automatic bag making both in bags with handles (shopping bags or shoppers) and in bags without handles (bags with openings), continuous materials, which are generally made of thermoplastic materials, are used as starting materials. It is common to use tubular elements.

The continuous tubular element described above is then bent inwardly on its opposite longitudinal sides, in the form of a branch, referred to herein as the "bellows forming portion". Appropriate areas are provided. These bellows forming portions can be widened and deployed in an open state, and a bottom portion having a predetermined width can be obtained,
But this bottom is not flat.

In practice, immediately after the continuous tubular element provided with the longitudinal double-sided bellows formation is produced, the next stage of production is the appropriately designed transverse welding rod (transverse well). Ding rod) is used. This horizontal welding rod is intermittently connected to the mouth of the bag (open or closed mouth).
And forming a weld for closing to obtain the bottom of the bag, the weld forming both the opposite sides of the flattened tubular element and the inside of the two bellows formations. Seal with a single weld.

The use of the bags described above is now fairly widespread and in continuous growth. The bags described above also have a lateral expansion, even if these bags are given to the bag by the sum of the dimensions of the sides of the flattened tubular element and the dimensions of the inner sides of the bellows which are flared together. It is used to accommodate objects having a certain weight, even though it provides a bottom of limited size as compared to.

Therefore, it has been considered necessary to make a bag having a wider bottom, for example a bag having a flat bottom having a certain robust strength.

To date, no means has been found to solve the above-mentioned rather important technical problem.

Accordingly, it is an object of the present invention to provide a means for solving the above technical problem by making a wide flat bottomed bag.

Another object of the invention is of particular benefit,
It is also to provide a flat-bottomed bag which can fulfill the above-mentioned functions and which is particularly simple to manufacture.

Yet another object of the present invention is to provide a flat bottomed bag which can be automatically manufactured without the need for any human intervention to complete the bag.

The above object according to the present invention is achieved by providing a flat-bottomed bag and a manufacturing method thereof as described below.

That is, according to the present invention, in a bag with a flat bottom obtained from a flattened tubular element provided with both-sided bellows, the flat bottom has a quadrilateral shape and each of the side portion and the bellows of the tubular element. It is characterized in that it is obtained from a bottom element with peripheral welds applied at the edges.

Preferably, the peripheral weld is made as a first part thereof between the side of the flattened tubular element and the first opposite sides of the bottom element, and As a second part thereof between the side of the inner bellows of said flattened tubular element and the remaining two sides or inner edges of the two opposite inner bellows of said bottom element. Is characterized by.

The present invention also provides a method of manufacturing a bag with a flat bottom, wherein a flat tubular element having bellows on both sides is formed, and a periphery of the tubular element and a dimension of the bellows. Obtaining a quadrilateral bottom of a single piece having a dimension equal to the dimension given by the sum of, and folding the bottom of this single piece along its first fold line, Maintaining two outer sides parallel to the fold line and of dimensions equal to the initial dimension, and folding the other two sides of said bottom into the same two bellows to make them identical. Arranging the central fold line in a position perpendicular to the first fold line, and inserting the bottom element thus folded into the flattened tubular element,
Two opposing bellows straddling the side bellows of the flattened tubular element, the outwardly facing end of the flattened tubular element and the corresponding end of the side bellows, respectively. Welding to the outer edges of the outer portion and the inner edges of the two opposing bellows obtained on the bottom, the dimensions being parallel to one fold line and equal to the initial dimension of the bellows. And

Preferably, the bottom element is obtained as having a rectangular shape.

The features and advantages of the flat-bottomed bag and the method for manufacturing the same according to the present invention will become more apparent from the following description of the embodiments, which are given merely as non-limiting examples with reference to the accompanying drawings. Let's do it.

With reference to all FIGS. 1-5, there is a flat bottomed bag according to the present invention, indicated generally by the numeral 11 in these Figures, and which is novel and inventive. A flat-bottomed bag obtained by the method of constructing the idea is schematically shown.

The flat-bottomed bag 11 is a flat tubular element 12
The tubular element is provided with double-sided bellows formations 13 which are folded towards the interior thereof.

When completed, the bag 11 has an opening 1
4 and a quadrilateral base 15. The quadrilateral base 15 has a rectangular shape in the case shown in the example of FIG. 4, but it can also be a square.

In the folded state, the bag 11 comprises a bottom element 16 inserted inside the open end of a flattened tubular element 12, the free edges of both of these elements pointing outwards and being aligned. , And one is above the other.

The bottom element 16 is first made into a quadrilateral sheet (see FIG. 2), which is folded in two halves along a first fold line 17 to form said first fold line 17. It maintains two parallel outer parts or parallel edges 18, these outer parts 18 having dimensions equal to the initial dimensions.

Next, the second operation performed on the bottom element 16 described above.
In the working stage of the above, two side parts 19 are further folded in order to make the two opposite bellows 20 identical, and the center fold line 21 of the identical bellows 20 is replaced by the first fold line 1
Set to the position perpendicular to 7.

After the bottom element 16 has been folded as described above, the bottom element 16 is inserted inside the aforementioned flattened tubular element 12 and its two opposing bellows 20 are flattened tubular elements. Straddle side bellows 13 of 12.

This method results in the configuration and arrangement shown in FIG. 1, except for welding. In fact, at this point
The step of welding the outward facing end of the flattened tubular element 12 opposite the opening 14 to the corresponding end of the side bellows 20 of the bottom element 16 is performed.

During the operation described above, the outer parts 18 of the bottom element 16 parallel to the first fold line 17 are maintained and these outer parts 1 are
8 are aligned with the ends of the flattened tubular element 12. Welding is peripheral welding, and this peripheral welding is the first
In the part 22 of the flat tubular element 12 the remaining side of the flat element 12 is joined to the side 18 of the bottom element 16 and in its second part 23 the inner bellows of the flat tubular element 12; The sides of 13 are joined to the sides or inner edges of two opposite inner bellows 20 of the bottom element 16. Of course, this is done while the two bellows 20 are left folded together.

A peripheral weld is then made between the sides and bellows of the flattened tubular element 12 and the sides and bellows of the bottom element 16, which results in a bag which is flared. It has a quadrilateral flat bottom in the opened state.

An outboard bag with a quadrilateral flat bottom can also be obtained by a method different from that described above, so the invention is also very simple, regardless of how the bag is obtained. Also related to said bag of construction.

From the above, it will be seen how the bag with a flat bottom and the method for producing the same shown according to the present invention achieve the above-mentioned object.

The above-described method for producing a bag with a flat bottom according to the present invention and the bag obtained by this method can be subjected to many variations and modifications without departing from the scope of the present invention.

Furthermore, in practice, the materials used, their size and composition can be varied according to the technical requirements.

[Brief description of drawings]

FIG. 1 is a side view of a bag made according to the present invention in a folded state.

2 is a plan view of a bottom element in a flattened, unattached state, which bottom element is then shown in FIG.
It is built into the bag.

FIG. 3 is a perspective view of the bottom element of FIG. 2 folded and prepared for insertion inside an initial tubular element having an outer shape similar to that shown in FIG.

4 is a perspective view from below of the bag of FIG. 1 when it is partially unfolded in use and provided with the flat-bottom element shown in FIG. 2;

5 is an enlarged view of the closed bottom end portion of the bag of FIG.

[Explanation of symbols]

11 bags 12 tubular elements 13 side bellows 14 Opening mouth 15 quadrilateral bottom 16 bottom element 17 First fold line 18 Outer part 19 sides 20 Bellows 21 center fold line 22 First part of peripheral welded part 23 Second part of peripheral welded part

Claims (4)

[Claims] 1. A flat-bottomed bag obtained from a flattened tubular element (12), comprising bilateral bellows (13), wherein said flat bottom is quadrilateral and the sides and bellows of said tubular element. A bag with a flat bottom, characterized in that it is obtained from a bottom element (16) with peripheral welds applied to each end of the. 2. A flat-bottomed pouch according to claim 1, wherein the peripheral weld is the side of the flattened tubular element (12) and the bottom element (16) as a first portion (22) thereof. Between the first opposite sides (18) of the
As a second part (23) of the flattened tubular element (12) the side of the inner bellows (13) and the two opposite inner bellows (20) of the bottom element (16) remain. A bag with a flat bottom, characterized in that it is made between one side or an inner edge (19). 3. A method of manufacturing a flat-bottomed bag, the method comprising the steps of making a flattened tubular element (12) comprising bellows (13) on both sides, the circumference of said tubular element and the dimensions of said bellows. Obtaining a quadrilateral bottom (15) of a single piece having a dimension equal to the dimension given by the sum of the dimensions and the bottom of this single piece at its first fold line (17)
Folding along, two outer parts (18) parallel to this first fold line (17) and of dimensions equal to the initial dimensions
And the other two sides (19) of the bottom are folded into two identical bellows (20) and the center fold line (21) of these identical bellows is folded into the first fold. Positioning perpendicular to the line (17) and the flat element (1) of the bottom element (16) thus folded.
2) inserted inside, so that said two opposite bellows (20) of said bottom straddle said side bellows (13) of said flattened tubular element (12), and said flattened The outer facing end of the tubular element and the corresponding end of the side bellows are respectively connected to the first fold line (1
7) and welding to the outer edges (18) parallel to the initial dimensions of the bellows and to the inner edges of the two opposing bellows (20) obtained on the bottom. A method characterized by: 4. Method according to claim 3, characterized in that the bottom element (16) is obtained as having a rectangular shape.