JPH0419095B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to plastic carrier bags.

Due to their simplicity, plastic carrier bags are very widely used, and the manufacturing industry has formed a huge market.

As one of these plastic carrier bags, a very distinctive plastic carrier bag was produced by the Special Publication Corporation in 1973.
Proposed in No. 39342. The hand part of this bag is
Initially, it was folded into the upper part of the bag body, and its unique feature was that the handle part could be pulled out and used. The bags proposed here include one in which the hand film 4 is attached to the outside of the opening 2 as shown in Figure 1, and one in which the hand film 4 is attached to the inside of the opening 2 as shown in Figure 2. There are two types of things.

The former type of plastic carrier bag is convenient to use because all you have to do is grab the bag with your hands when pulling out the handle, but it is difficult to manufacture.

On the other hand, manufacturing a plastic carrier bag as shown in FIG. 2 is simple. When manufacturing this, a long tube-shaped film is gusseted as shown in the cross-sectional view of FIG. 3, cut away at the fold line 8 in the figure, and then subjected to a bag-making process to form a bag. On the other hand, the plastic carrier bag shown in FIG. 1 has to be cut first and then the unsupported edges of the bag must be folded outward as shown in FIG. 4, which makes the process extremely difficult. It is very difficult to cut such a long tube-shaped film and then bend its free-moving end in a continuous automatic process.

In fact, although the plastic carrier bag of the type shown in Figure 1 is convenient to use, the only plastic carrier bag of the type shown in Figure 2 is currently on the market. It is assumed that there are difficulties in manufacturing the mold.

Further, in the plastic carrying bag proposed in the above-mentioned patent publication, the carrying portion film 4 is composed of only one film. Since the handle film 4 is of the same quality and the same thickness as the bag film 1, it cannot balance the strength of the bag body, and the handle film 4 tends to break when heavy items are put in it. have.

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved and simple method for manufacturing a plastic carrier bag, which has improved strength in the handle portion of the plastic carrier bag proposed in the above-mentioned patent publication.

In the present invention, four rows of gusset folds each having a width corresponding to the width of the handle film are provided on the upper and lower sides of a long tube-shaped plastic film symmetrically with respect to the center line. Separate the left and right sides, put a plate inside each long gusset folded film, and apply a hot iron from above and below to the gusset folds near the upper left and right corners of the bag body, matching the period of the width of the bag body. is pressed against the plate, and on the diagonal line extending below the bag body, a total of three films, the double hand part film and the opening film are fused at the top and bottom respectively, and both ends of the hand part film are attached to the bag body. The handle film is separated from the opening by cutting off the middle part of the upper side of the bag body, and the film is fused and cut at each width of the bag body to cut the left and right edges of the bag body. The present invention provides a method for manufacturing a plastic carrier bag, which is characterized by fusing together.

The present invention will be explained in detail with reference to drawings of embodiments. In the plastic carrier bag shown in Fig. 5, the two rectangular films on the front and back are integrally connected via the bottom part 3, and the left and right side edges are fused by the side edge welding part 6 to form the bag. A film 1 is formed. The bag film 1 used here is not only a vertically long rectangle as shown in the figure, but also a horizontally long rectangle and a square. The handle film 4 is extended from the opening film 13 on both the front and back sides by being bent outward at the fold line 9, and is further folded outward again at the fold line 8, so the handle film 4 has a double structure. It's getting old.

The cutout 17 in the upper center of the opening 2 allows the holding part back film 12 and the opening part film 13 to be separated.
are separated, and the bag can be suspended by inserting a finger into the cutout 17. The width of the cutout portion 17 can be appropriately selected depending on the form of the bag.

At the hand fixing part 5 that extends below the left and right sides of the upper part of the opening 2, three sheets, the hand part front film 11, the hand part back film 12, and the opening part film 13, are fused at the front and back openings 2, respectively. Fixed. The angle of the hand holding part 5 which is fixed diagonally can be freely selected, but from a mechanical point of view it is preferably 45 degrees. The length of the handhold fixing part 5 can be increased depending on the weight of the bag body part. The position of the hand holding part 5 can be selected as appropriate depending on the shape of the bag as well as the width of the cutout part 17. That is, increasing the interval between the left and right hand holding portions 5 and the width of the cut-out portion 17 increases the length of the hand holding portion film 4, and decreasing the width shortens the length of the hand holding portion film 4.

This should be selected depending on the shape of the bag and the width of the hand film 4. Usually, it is often desirable to provide the handle part 5 at the upper part of the opening part 2 as close to both corners as possible because the handle part 5 becomes longer.

If necessary, make a gusset fold on the bottom 3,
By fixing two films, the bottom inner film 15 and the bottom outer film 16, on the front and back sides at the square bottom fused portion 18, the bottom 3 of the bag can be formed into a square bottom shape. The square bottom structure is a suitable bottom structure for the plastic carrying bag of the present invention in which the carrying film 4 is reinforced since the bottom part 3 is highly reinforced.

In the thus obtained plastic carrying bag of the present invention, the carrying part film 4 is double-layered, and the lower edge of the carrying part film 4, which is subject to heavy loads, forms a fold 8, so that tearing peculiar to plastic films is avoided. There are no obvious drawbacks.

Another aspect of the present invention is to provide gusset folds with a width corresponding to the width of the hand portion film on the left and right sides symmetrically with respect to the center line on the upper and lower sides of a long tube-shaped plastic film. Cut this into left and right parts, insert a plate inside each long gusseted film, and apply heat from above and below to the gusseted folds near the upper left and right corners of the bag body, matching the period of the width of the bag body. Press the iron against the plate and place it on the diagonal line extending below the bag body,
Fuse three pieces of film each on the top and bottom, and fix both ends of the hand film to the left and right upper corners of the bag body.
The handle film is separated from the opening by cutting off the center part of the upper side of the bag body, and the left and right side edges of the bag body are fused by cutting the film according to the width of the bag body. It consists of a method of manufacturing a plastic carrier bag.

Next, this manufacturing method will be explained in detail using examples.

A long tube-shaped film is gusseted to have a cross section as shown in FIG. That is,
Make the same folds symmetrically on the left and right sides and above and below the center line of the tube-shaped film. In the figure, it is folded at four folds 9 on the top, bottom, left and right, and is also folded at four folds 8.

When the bottom of the carrier bag of the present invention is made into a square bottom shape,
As shown in FIG. 7, gusset folds may be provided at both ends of the tube-shaped film by folding at creases 7 and 10.

Hand part front film 11 and hand part back film 12
The width of the holding portion film 4 is the same as that of the holding portion film 4. The width of the square bottom gusset is determined by the required thickness of the bag body.

When the left and right sides of the thus obtained gusset-folded tube-shaped film are separated along the center line, two rows of long gusset-folded films having the cross section shown in FIG. 8 are obtained. The following steps are performed for each of the left and right gusseted long films.

As shown in FIG. 9, hand fixing parts 5 are continuously formed at the upper right and left corners of the opening 2 while pulling out the long film. This is front and back bag film 1
A metal plate is inserted between them, and a hot iron is pressed against the plate from both the top and bottom, and the three parts of the hand part front film 12, the hand part back film 12, and the opening film 13 are pressed on the top and bottom surfaces of the plate, respectively. The sheet is fixed at the position of the hand holding part 5. As described above, the hand holding portion 5 is a diagonal line that extends downward from the bag body.

Before or after the step of providing the handhold fixing portion 5, a step of providing the cutout portion 17 is performed. Through this process, the hand portion back film 12 and the opening portion film 13 are separated. When making a square bottom in the bag body part, simultaneously with these steps, the bottom inner film 15 and the bottom outer film 16 are fixed at both left and right corners of the bottom 3 using the square bottom fusion parts 18.

Finally, fusing and cutting is performed at the side edge fused portions 6 for each width of the bag body portion, and the side edges are fused to form the bag body portion, and the plastic carrier bag of the present invention is completed.

In the process of the present invention, if the fold line 8 of the handle portion of the long gusset-folded film that has been cut to the left and right is first extended, the handle portion of the type shown in FIG. It is easy to manufacture carrier bags.

The present invention makes it possible to efficiently and easily manufacture plastic carrier bags that are convenient to use and strong, and is very useful for the bag making industry, which has a large market.

[Brief explanation of drawings]

1 and 2 are perspective views of a known plastic carrier bag, and Figures 3 and 4 are sectional views of a tube-shaped film for explaining the manufacturing process of a known plastic carrier bag. Figure 5 is a front view of one embodiment of the plastic carrier bag of the present invention, Figure 6 is a longitudinal sectional view thereof, and Figures 7 and 8 are for explaining the manufacturing process of the plastic carrier bag of the present invention. FIG. 9 is a cross-sectional view of the film of
The figure is also a plan view. The symbols in the figure are: 1; bag film; 2; opening; 3; bottom; 4; hand film; 5; hand fixing part; 6; side edge fusion part;
7, 8, 9, 10; Fold line, 11; Front film of hand portion, 12; Back film of hand portion, 13; Opening film, 14; Center line, 15; Bottom inner film, 16; Bottom outer film, 17; Stamping Notch part 18; is a fused part for a square bottom.

Claims (1)

[Claims] 1. Four rows of gusset folds with a width corresponding to the width of the handle film are provided on the upper and lower sides of a long tube-shaped plastic film symmetrically with respect to the center line, and the gusset folds are folded left and right at the center line. Place a plate inside each long gusset folded film, and apply a hot trowel from above and below to the gusset folds near the upper left and right corners of the bag body according to the period of the width of the bag body. Press it against the plate
On the diagonal line extending below the bag body, fuse a total of three films, the double hand film and the opening film at the top and bottom respectively, and fix both ends of the hand film to the upper left and right corners of the bag body. The handle film is separated from the opening by cutting off the middle part of the upper side of the bag body, and the film is fused to each width of the bag body to fuse the left and right side edges of the bag body. A method of manufacturing a plastic carrier bag.