JPH01101144A - Manufacture of handbag with square bottom - Google Patents

Abstract

PURPOSE: To provide a handbag with square bottom which has high toughness and good appearance by coating a position to be thermally cut by a heated blade between gusset folded parts with an antifusion agent in the square bottom making process for easily perform the thermal cutting. CONSTITUTION: The colorless ink as the antifusion agent 8 is printed on the central part of a long band film with a specific width, the film is folded in halves along the longitudinal direction in a state that the printed face faces outside, and then the folds are folded inside to obtain the gusset fold, whereby the band film having the gusset fold 5 and the gusset fold 6 can be obtained. When a wedge-shaped heated blade is pressed from an upper part to the folded part between the gusset fold 5 and the gusset fold 6, the upper and lower two sheets of films of the gusset fold are fused corresponding to the wedge-shape of the heated blade to form the square bottom fusion 9, and the unnecessary film 12 is cut off. On this occasion, as the antifusion agent 8 is applied between the gusset folds 5, 6, the semi-fusion of the square bottom fusion part 10 can be easily separated only by inserting a finger between the lower edges of the gussets folds 5, 6 to open the same.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a square-bottomed plastic film carrying bag.

BACKGROUND OF THE INVENTION At present, plastic film bags are used in large quantities for packaging and transporting goods, especially in supermarkets and the like.

We also have bags such as plastic film bags,
Bags with a so-called square bottom structure having a rectangular bottom are particularly preferred because they are convenient for storing items.

[Prior Art] Various methods of manufacturing the square bottom structure of the plastic film bag, which is the object of the present invention, have been proposed.

A widely used method is to provide a gusseted fold at the bottom of a plastic film and fuse the film to the left and right corners of this portion at an angle of about 45 degrees to form a square bottom structure.

In the square base manufactured by this conventionally widely used technique, a double-structure right isosceles triangular film is attached to the lower part of the outside of the left and right sides of the square base with the right angle point facing upward.

The outer film of this double structure not only does not contribute anything to the strength of the square bottom, but also has a poor appearance and is difficult to handle and inconvenient when used in a bag with a wide square bottom.

Furthermore, when manufacturing a square bottom using the conventional method, the angle of the fused portions at the left and right corners is limited to 45 degrees.

In other words, if this angle is smaller than 45 degrees with respect to the bottom edge of the bag, the right-angled isosceles triangle of the extra attached double film will have a base longer than the width of the square base, and when made into a square base, , the adhesive film is loose and has a poor appearance. on the other hand,
When this angle is larger than 45 degrees, the length of the bottom of the adhesive film becomes shorter than the width of the square bottom of the bag, and the width of the square bottom is limited by the adhesive film, which in turn causes slack at the bottom of the bag.

As a manufacturing method of a square bottom structure free from such defects, the present inventors first cut off the unnecessary film by fusing and cutting using thermal power, thereby creating a bag with a good appearance without any excess film attached. proposed a method for manufacturing (Japanese Patent Application Laid-Open No. 61-261031).

However, when using this method, it is necessary to insert a plate in between the cutting process using thermal force and perform it from both the upper and lower sides, which has the disadvantage that the operation is complicated.

[Problems to be Solved by the Invention] An object of the present invention is to provide a method for easily manufacturing the carrier bag having the square bottom structure.

[Means for solving the problem] In the process of manufacturing and selling the previously developed carrier bag with a square bottom, the inventor deepened the folding of the square bottom,
Increasingly, products with a bottom shape that is close to a square are being manufactured.

In such cases, it has become difficult to carry out the conventional process of inserting a metal plate into the folded or gusseted part and applying heat from above and below to fuse it.

In order to deal with this, the present inventor came up with the idea of applying a method of applying an anti-fusing agent to the square bottom process at the position between the folded parts of the gusset, which is to be fused by thermal force, and has come up with the present invention. Ta.

The present invention is a method of bag making in which a long tube-shaped plastic film or a half-folded strip-shaped plastic film raw material, which is the raw material for the bag body part, is continuously fed out and the film is fused for each width of the bag body. In the process, a carrying part is provided at the top, a gusset fold is provided at the part corresponding to the bottom of the bag of the original film, and an anti-fusing agent is applied at a position corresponding to the fusion line between the gusset folds, and then A wedge-shaped hot blade is pressed against each width of the bag to fuse the two pairs of films on the front and back sides, and the part of the film surrounded by the wedge shape is cut off by melting, and the bag is separated. A linear hot blade is pressed against the film material for each width,
This method of manufacturing a square-bottomed carrying bag is characterized in that the side edges of the bag are formed by fusing and cutting the bag.

The tubular film material used in the present invention can be produced by inflation processing and used as it is.

Further, a half-folded film can be used by cutting open one end of the above-mentioned blown film, or by folding a long raw film in half.

In the process of fusing and cutting the gusset folded portion in the present invention, an anti-fusing agent is applied between the two sets of gusset folded films in order to prevent the two sets of gusset films from fusing together. Although it is sufficient to apply this coating only to the area where fusing and cutting is to be performed, it is often more efficient to apply the coating to the entire inner surface of the gusset fold.

The anti-fusing agent used in the present invention can be applied to films like ink, and any anti-fusing agent can be used as long as it prevents the films from fusing together. be able to.

For example, printing ink, silicone paste, etc. can be used as such substances.

In the present invention, when the part coated with the anti-fusing agent is subjected to heat fusing treatment, it is usually in a semi-fused state and can be easily peeled off by hand.

Then, a wedge-shaped thermal force is applied to a metal base or the like from above the gusset fold to form a fused portion, and the wedge-shaped unnecessary film surrounded by the thermal force is cut off at the same time from above and below.

At this time, either mechanically scrape off the separated film or
It is desirable to add a step of blowing off the film with compressed air. If this is not done, the cut off unnecessary film will cause problems in the subsequent process of fusing and cutting the side edges of the bag.

In the wedge-shaped thermal force fusing process, it is desirable that the apex of the wedge-shaped thermal force correspond as closely as possible to the inner fold line of the gusset fold.

After or simultaneously with the step of fusing and cutting the corner bottom portion, a portion corresponding to the side edge of the bag body portion is fusing and cutting to fuse and cut the side edge of the bag body. At this time, it is necessary to cut the material so that it coincides with the apex of the wedge shape.

[Example] The manufacturing method of the present invention will be explained in more detail with reference to Examples.

Colorless ink is printed as an anti-fusing agent at a certain width in the center of a long strip of film, with the printed side facing outward.
The film is folded in half along the longitudinal direction, the folds are reversely folded inward, and the film is gusset-folded to form a strip-like film having gusset folds 5 and 6 as shown in the cross-sectional structure of FIG.

As a result, the anti-fusing agent 8 is applied to the inner surface of the gusset fold.

These gusset folds are performed to form the bottom of the carrier bag into a square bottom structure.

Next, while feeding the gusset-folded strip film onto a workbench, a front tape film 3 and a back tape film 4 are placed on the upper surface of the front film L and the lower surface of the back film 2, respectively, along the upper edges of each. Supply along. The cross-sectional structure of the strip-shaped film assembled in this way when viewed from the side is as shown in FIG.

Next, in a conventional manner, the feeding method of the film strip is switched to intermittent feeding in which the film strip is temporarily stopped, and the film strip is fed onto the fusing workbench. On the fusing workbench, a metal plate 7 is installed between the front film 1 and the back film 2 at the upper edge of the strip-shaped film. This metal plate 7 is inserted from above the strip-shaped film.

On the other hand, between the folded portions of the gusset folds 5 and 6, there is a pre-applied anti-fusing agent.

There is a gap in the welding workbench where the metal plate for fusing the handle part on the upper edge is installed, and the hot iron is passed through this gap to insert the metal plate from under the table. You can press it against the bag and fuse the handbag part on the back.

A hot iron is applied to the metal plate 7 on the fusion workbench from above and below. An inverted V-shaped hot iron as shown in FIG. 2 is pressed against the metal plate 7 inside the upper edge of the film strip from above and below at the same time. At this time, the front film 1 and the front tape film 3
As shown in the diagram between
is formed.

And between the back film 2 and the back tape film 4,
Similarly, handbag fusion is formed, but the front film 1 and the back film 2 are not fused because they are blocked by the metal plate.

At the same time as this fusion step, the folded portion between the gusset folds 5 and 6 is pressed from above with a wedge-shaped thermal force as shown. At this time, the upper and lower 2-sheet sets of gusseted films are each fused in a wedge shape with 5 heat blades per 2 sheets to form a square bottom fusion bond 9, and the unnecessary film 12 is cut off.

The separated unnecessary film 12 is mechanically scraped off, or
Remove by blowing out with compressed air.

At this time, since an anti-fusing agent is applied between the gusset folds 5 and 6, the square bottom fused portions 10 of these films are lightly semi-fused.

If a case is inserted between the lower edges of the gusset fold 5 and the gusset 6 and opened, the semi-fused part of the square bottom fused part 10 can be easily peeled off.

After the fusing step, the film strip is fed to the workbench for the final fusing step. Here, the strip-shaped film is fused in the transverse direction in accordance with the position of the apex of the fused wedge provided in the gusset fold, which is the width of the bag. By this fusing and cutting step, it is possible to simultaneously cut the bag body into widths and fuse the side edges of the bag body 11.

In the carrying bag of the present invention, various known configurations can be applied to the structure of the carrying part.

For example, using a tube-shaped inflation film as a raw material, punching out the upper part in a W shape to form a handbag part and a tie string for day seals, and making these film tapes a continuous integral structure with the bag part. You can also do it. In this case, there is no need to insert a metal plate into the upper part, which simplifies the process.

[Operation] Through the above steps, a carrier bag as shown in the plan view of FIG. 3 can be manufactured. When the bag is expanded according to the square bottom structure, the structure shown in Figure 4 will be obtained. Of course, FIG. 4 is shown as an explanatory drawing, and since the film is flexible at the upper edge of the bag, it does not have a square shape as shown in the figure. In this way, the bag can be hung by unfolding the bag, placing an item inside, and grasping the tape-like film of the carrying portion from the outside.

In the production of the present invention, if the bottom melting and cutting step is carried out at an angle of 45 degrees with respect to the lower side of the bag, the bottom of the bag will become exactly a rectangular parallelepiped when the bag is expanded. However, this angle 4
If the angle is smaller than 5 degrees, the bottom of the bag will take on a boat-bottom shape in which the intersection of the square bottom fused portion and the side edge fused portion protrudes from side to side. vice versa,
When the angle is greater than 45 degrees, a bag can be manufactured in which the bottom is wider than the opening of the bag, as shown in FIG.

Furthermore, if the depth of the gusset fold is increased, the bottom surface of the square bottom becomes square, making it possible to produce a bag with a three-dimensional view like the fifth factor.

In this way, by gradually changing the thermal inclination angle of the wedge shape, and by combining this with changing the depth of the fold of the gusset fold 5, it is possible to create bags with bag bodies of a wide variety of shapes. You can make it as you wish.

[Effects of the Invention] The present invention allows bags with complex shapes to be easily manufactured as desired, and in particular, when manufacturing bags with deep gusset folds, the present invention does not require conventional metal plates to be inserted between them and fused together. In the method of preventing this, not only is the process of inserting the metal plate difficult for deep gusset folds, but also for shallow gusset folds, when the metal plate is pushed to the very edge of the gusset fold, it is difficult to insert the metal plate. In order to use this as a cutting table, it is necessary to press the tip of the front cutting blade several inches away from the edge of the table.

Therefore, the two left and right square bottom fused parts 10 and the side edge fused parts 11
Since the princess difference points between the two are not concentrated exactly at one point, the appearance of the bag is poor and the strength of the princess difference points is low.

In the method using the anti-fusing agent of the present invention, the tip of the thermal force can be accurately pressed almost to the line-cup of the gusset fold, so the three fused parts are concentrated at one point, and the fusing process is completed. Not only is this easy, but the square-bottomed carrier bag can be made durable and good-looking.

The present invention makes it possible to efficiently manufacture such strong, stylish, and convenient to use carrier bags through a simple process, and is very useful for the bag manufacturing industry.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams for explaining aspects of an embodiment of the manufacturing process of the present invention, and Figures 3 and 4 are diagrams for explaining the structure of a handbag with a square bottom structure manufactured by this embodiment. FIG. 3 is a plan view of the folded state, and FIG.
The figure is a perspective view of the bag when the square bottom part is unfolded, and FIGS. 5 and 6 are perspective views of another embodiment of a carrier bag having a square bottom structure according to the present invention in a state of use. . The numbers in the figure are 1: front film, 2: back film, 3: front tape film, 4: back tape film, 5.6: gusset fold, 7: metal plate for fusing the handbag part, 8: anti-fusing agent layer. , 9: Handbag fused portion, IO: Square bottom fused portion, 11: Side edge fused portion, 12: Unnecessary film. Patent applicant Masayoshi Matsumoto

Claims (1)

[Claims] 1. In the bag-making process in which a long tube-shaped plastic film or a half-folded strip-shaped plastic film raw material, which is the raw material for the bag body part, is continuously fed out, the film raw material is fused for each width of the bag body, A carrying part is provided at the top, a gusset fold is provided at the part corresponding to the bottom of the bag of the original film, and an anti-fusing agent is applied to the position corresponding to the fusion line between the gusset folds, and then the bag body is A wedge-shaped hot knife is pressed against each width of the bag to fuse the two pairs of films on the front and back sides, and the part of the film surrounded by the wedge shape is cut off by melting. A method for producing a square-bottomed carrier bag, which is characterized by pressing a linear hot knife against a film material and fusing it to form a side edge of the bag body.