JPS5942338Y2 - multilayer bag - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a multilayer bag for storing contents that do not absorb moisture, such as ordinary salt.

Conventionally, as a bag for storing the contents as described above, the bottom of the main body made of multiple layers of paper or paper and synthetic resin film is closed with a sewing machine, and the opening is closed with a sewing machine after the contents are contained. It has been known that the wound was closed with stitches.

In such conventional salt bags, there is a concern that if dew forms on the inner wall of the bag due to the dew point phenomenon, the salt contained in the bag may solidify.

For this reason, the innermost layer of the bag is now made of a craft surface instead of a synthetic resin surface, but this structure had the disadvantage that it was difficult to heat seal the mouth and bottom to provide moisture resistance. .

The purpose of the present invention is to eliminate the drawbacks of the conventional bags mentioned above, improve the moisture resistance of the mouth and bottom parts, and provide a multilayer bag with increased strength in these parts at a low cost. It is something to do.

Hereinafter, an embodiment of the multilayer bag of the present invention shown in the drawings will be described in detail.

FIG. 5 shows a multilayer bag according to an embodiment of the present invention.

This multilayer bag is formed as follows.

That is, as shown in Fig. 1, processed papers 1 and 2, each of which is laminated with a hot melt resin such as polyethylene on one side, and paper 3, such as ordinary kraft paper, are each wound into a coil shape. The processed paper 2 is fed out, and glue is sequentially applied to the processed paper 2 at predetermined intervals by a gluing machine a. During this time, the processed paper 1 is cut into a predetermined length by a cutter b, and the cut pieces of the processed paper 1 are cut into processed paper. 2, and these are pressed and pasted with a press C.

At that time, the cut pieces of processed paper 1 are cut so that the hot melt resin side will be on the inner side of the bag when the bag is made as shown in FIG.
The plain processed paper 2 is made such that its hot melt resin surface faces outward and the craft surface is located on the inner surface.

Note that the adhesive is applied to the processed paper 2 so that the entire cut piece of the processed paper 1 that will serve as the reinforcing paper for the opening and bottom is adhered to the processed paper 2, or it is applied in a striped or dotted pattern. It may be either.

The cut pieces of the processed paper 1, that is, the processed paper 2 to which the reinforcing paper 4 has been pasted, are superimposed on the paper 3 as shown in FIG.
Next, it is bent along the chain line B and formed into a cylinder by pasting both side edges together, and the cylinder (not shown) is cut off at the cutting position A shown in Fig. 2. From this point, each bag is cut into pieces. A mounting body is formed.

The packaging body at this stage is a tube with processed paper 2 as the innermost layer and paper 3 as the outer layer, and the reinforcing paper 4 faces the innermost layer of the bag at its mouth and bottom with its hot melt resin surface facing toward the inside of the bag. This is a tube attached to the inner surface of the processed paper 2 so that it looks like this.

As described above, the resin processed surface of the innermost layer of processed paper 2 is located on the outer surface.

Next, as shown in FIGS. 3 and 5, the bottom end of the packaging body 5 is heated and pressurized, and the heat-sealed portion 8 formed by bonding the opposing surfaces of the reinforcing paper 4 to each other is attached to the bottom end. Formed at the end.

Then, a padding paper 6 is applied to the bottom of the packaging body 5, spanning the front and rear surfaces of the bottom, and a sewing machine is applied to the part of the padding paper 6 where the reinforcing paper 4 is located to close it. be done.

After filling the multilayer bag thus formed with contents such as ordinary salt, the opening is heat-sealed and thinly sewn in the same way as the bottom, as shown in Figure 5. Do it and get blocked.

That is, a heat-sealed portion is similarly formed at the opening of the packaging body 5, and the patch paper is sewn onto the packaging body 5 using a sewing machine.For the sake of simplicity, the same reference numerals are given to the corresponding parts. The explanation will be omitted.

Note that the hot-melt adhesive applied to the inner surface of the reinforcing paper to form the heat-sealed portion may be applied at an appropriate time during the bag-making process.

Furthermore, the main body may not be composed only of paper or processed paper, but may also include a synthetic resin film layer.

As explained above, in the multilayer bag of the present invention, reinforcing paper is arranged around the entire inner circumference of the innermost layer at the mouth and bottom, and the inner surface, that is, the opposing surface of this reinforcing paper is a heat-sealable surface. Further, machine stitching is performed in the width direction of the bag at the part where the reinforcing paper is located, and only the inner surface of the reinforcing paper on the edge side of the mouth and bottom part from the sewing position is heat-sealed.

As a result, according to the multilayer bag of the present invention, it is possible to form heat-sealed portions at the mouth and bottom of the bag, thereby reliably blocking air permeability into the bag body and ensuring moisture resistance.

In addition, according to the present invention, the machine-stitched portions on the mouth and bottom portions are located closer to the center of the bag than the heat-sealed portion, which improves the strength of the heat-sealed portion.

In other words, in conventional bags that have a heat-sealed part, the sewing machine-sewn part is located closer to the mouth and bottom edges than the heat-sealed part, so stress is first applied to the heat-sealed part, and the innermost layer to be heat-sealed becomes film-like. With processed paper that does not stretch, the heat-sealed portion easily peels off, resulting in no moisture resistance.

However, in the present invention, since the stress is supported by the thin seam portion, separation of the opposing surfaces of the reinforcing paper forming the seal portion is prevented, and moisture resistance can be ensured.

In addition, a certain amount of air can be vented through the sewing machine needle hole in the □ thinly sewn portion located closer to the center of the bag than the heat-sealed portion.

For these reasons, the multilayer bag of the present invention is superior in terms of improving the moisture resistance of the mouth and bottom and increasing the strength of these parts, as a heavy packaging bag for contents such as ordinary salt that dislikes moisture absorption. be effective.

Furthermore, according to the present invention, since only the reinforcing paper located at the innermost layer of the packaging body is heat-sealed, it is easy to open the opening to take out the contents. Since the number of layers can be reduced by one layer, fewer materials are required and the material can be provided at low cost.

[Brief explanation of drawings]

Fig. 1 is a structural explanatory diagram schematically showing the apparatus for forming the multilayer bag of the present invention, and Fig. 2 is a fragmentary diagram showing the overlapping state of processed paper and paper in the process of manufacturing the multilayer bag of the present invention. FIG. 3 is a front view showing the main body with the bottom closed during the process of forming the multilayer bag of the present invention, and FIG. 4 is a perspective view of the main body shown in FIG. FIG. 5 is a longitudinal sectional view showing a multilayer bag according to an embodiment of the present invention filled with contents. 2... Processed paper, 3... Paper, 4... Reinforced paper, 5...
・Base body, 600. Covering paper, 7..., thread, 8.1. Heat seal part.

Claims (1)

[Scope of utility model registration request] A device in which reinforcing paper is pasted over the entire circumference of the inner surface of the opening and the bottom, and the opening and the bottom are the parts where the reinforcing paper is and are closed by sewing them together along the edges of the reinforcing paper. In a multilayer bag having a main body, the reinforcing paper has a heat-sealable surface on its opposing inner surface, and only the inner surface of the reinforcing paper on the side of the edge of the opening and bottom part from the sewing machine sewing position is heat-sealed. Multilayer bag.