JPH09290842A - Packaging bag and production method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily unseal a packaging bag from an appropriate position of the rear seal part, by providing saw-like gathers continuously extending from the upper end to the lower end, at least at one end edge of the rear seal, in a packaging bag provided with the vertically extending rear seal at the rear face. SOLUTION: A plastic laminate film is folded and formed so that respective ends 2, 2 of the film project outward at the breadthwise middle position of the rear face and the joined ends are sealed with heat to form the rear seal part 3 and make a cylindrical pillow type packaging bag 1. The cylindrical part is folded to form both side parts 4, 4 and the opening end of the cylindrical part is sealed with heat. In this case, A saw-like gather 11 continuously extending from the upper end heat-sealed part to the lower end heat-sealed part is formed at the end edge of the rear seal part 3. In this way, the valley positioned between the adjacent chevron-shaped parts of the gather is used for the unsealing guide of the rear seal part 3. And hence, the rear seal part 3 can be easily unsealed by hands.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging bag in which the back seal portion can be easily opened from an appropriate position and a method for manufacturing the packaging bag.

[0002]

2. Description of the Related Art A packaging bag made of a commonly used cellophane, a composite film obtained by laminating a polyethylene film on paper, etc. can be easily opened by hand without using a cutter. However, this type of packaging bag has a low breaking strength and in particular lacks moisture resistance, so that the content to be enclosed is limited.

A packaging bag formed by using a plastic film as a raw material has a high breaking strength due to the high tear strength of the plastic film and is excellent in moisture resistance, so that the contents to be enclosed are not limited and the application range is widened. However, since it is difficult to open the heat-sealing part of the packaging bag by hand, there is a difficulty in using it as it is, and in order to easily perform the opening from the heat-sealing part,
V on the upper and lower heat seal parts of the packaging bag
Shaped notches and I-shaped notches are provided.

[0004]

In a packaging bag made of a plastic laminate film, if a V-shaped notch or the like is provided in the seal portion, it can be easily opened from the seal portion. Technically, it is limited to the upper end heat seal part and the lower end heat seal part of the packaging bag.
If the packaging material processing manufacturer delivers this notch to the upper and lower heat-sealing parts of the packaging bag, the packaging material processing manufacturer can roll the packaging material into rolls. When the material is delivered and the packaging bag is formed by the content filling machine, it cannot be applied to the upper end heat seal portion or the lower end heat seal portion of the packaging bag.

The present invention has been made in view of the above points, and an object of the present invention is to provide a packaging bag and a method for manufacturing the same, which can easily open the back seal portion from an appropriate position.

[0006]

In the packaging bag of the present invention, at least one edge of the back seal portion extending in the vertical direction is provided with a serrated gather continuously extending from the upper end to the lower end, whereby the back seal portion is formed. By opening from the appropriate position,
Since the packaging bag can be torn at an intermediate position in the vertical direction,
Even if the contents to be enclosed are fragile foods such as wafers, the contents can be taken out as they are.

According to the method of manufacturing a packaging bag of the present invention, serrated gathers are provided on at least one side edge of a continuous-length plastic laminate film, and the plastic laminate film is bent and formed in a state where both ends thereof are butted, and the butted joints are joined. By heat-sealing the end portion to form the tubular portion having the back seal portion, it is possible to position the serrated gathers on the back seal portion and open the packaging bag from an appropriate position of the back seal portion.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example in which the packaging bag according to the present invention is applied to a pillow type packaging bag. This pillow type packaging bag 1 is made of a plastic laminate film material having a rectangular shape and having ends 2 and 2 joined together. Is bent and formed so as to project outward at an intermediate position in the width direction of the back surface, and the end joint portion is heat-sealed to form a back seal portion 3 into a tubular portion. 4 is formed by bending, and the open end of the tubular portion is heat-sealed.

The above plastic laminate film 5
As shown in FIG. 3, a biaxially oriented polypropylene film 6 having a thickness of 20 microns, a polyethylene layer 7 having a thickness of 15 microns, and a polyester film 8 obtained by vapor-depositing a metal film such as aluminum having a thickness of 12 microns. And a polyethylene layer 9 having a thickness of 15 microns and an unstretched polypropylene film 10 having a thickness of 20 microns.

A gather 11 is formed at the edge of the back seal portion 3 of the pillow type packaging bag 1 and extends continuously from the upper end heat seal portion to the lower end heat seal portion. The gather 11 is, for example, a sawtooth gather in which the mountain-shaped portions are formed at a pitch of about 7 mountains per 10 mm.

Since the pillow type packaging bag 1 is provided with the serrated gathers 11 continuously from the upper end to the lower end of the back seal portion 3, the serrated gathers of the adjacent serrated gathers 11 are formed. The valley portion located between them acts as an opening introduction portion of the back seal portion. Therefore, a strong force is required for the back sealing portion 3 with the valley portion between the mountain portions of the back seal portion 3 at an appropriate position as the opening introduction portion. It can be opened easily without hand.

The pitch of the chevron-shaped gathers 11 can be varied depending on the breaking strength of the plastic laminate film 5 and the orientation of each plastic film of the plastic laminate film.

Next, a method of manufacturing the pillow type packaging bag 1 will be described.

First, a continuous plastic laminate film 5 is produced by laminating a plurality of continuous plastic films via an adhesive layer. Preferably the plastic laminate film is a laterally oriented stretched film.

Next, the continuous plastic laminate film 5 is cut into a length in the width direction required for forming the packaging bag, that is, a predetermined length in a direction transverse to the flow direction of the film. By cutting the continuous plastic laminate film, saw-tooth gathers 11 are formed on at least one side edge of the cut plastic laminate film material.

Next, the cut plastic laminate film material is bent and formed so that both ends thereof are abutted, and the abutted joint ends are heat-sealed. By heat-sealing the joint end portion, a tubular portion having the back seal portion 3 is formed. Since the edge of the back seal portion 3 corresponds to the saw-tooth gather 11 of the cut plastic laminate film, the saw tooth-like gather 11 continuously extending from the upper end to the lower end is located at the edge of the back seal portion 3.

Then, the open end of the tubular portion of the packaging bag is heat-sealed by a normal heat-sealing process.

In the above embodiment, the case where the packaging material processing manufacturer delivers the packaging bag has been described. However, the packaging material processing manufacturer delivers the roll-shaped packaging material and forms the packaging bag with the content filling machine. In this case, serrated gathers are formed on a roll-shaped packaging material, and filling of contents and bag making are performed simultaneously.

FIG. 2 shows another embodiment of the present invention. The packaging bag shown in FIG. 2 is a gusset type packaging bag 20, and the gusset type packaging bag 20 has gusset portions 21 folded inward on both sides. This gusset-type packaging bag 20 is also provided with saw-tooth gathers 11 that continuously extend from the upper end to the lower end on the edge of the back seal portion 3, similarly to the pillow-type packaging bag 1 shown in FIG.

[0021]

As described above, the packaging bag of the present invention is
Since the saw-tooth gathers that continuously extend from the upper end to the lower end are provided on the edge of the back seal portion that extends in the vertical direction, the back seal portion can be easily opened from an appropriate position.

Further, in the method for producing a packaging bag of the present invention, a sawtooth gather is formed on the cut plastic laminate film before molding, and the butted joint ends of the cut plastic laminate film are heat-sealed to form a back seal. Since the portion is formed, gathers that continuously extend from the upper end to the lower end, which cannot be formed by the conventional packaging bag, can be formed in the back seal portion.

[Brief description of drawings]

FIG. 1 is a diagram showing an example in which a packaging bag according to the present invention is applied to a pillow-type packaging bag.

FIG. 2 is a view showing an example in which the packaging bag according to the present invention is applied to a gusset type packaging bag.

FIG. 3 is a cross-sectional view of a plastic laminate film which is a material for a packaging bag.

[Explanation of symbols]

 1 Packaging bag 3 Back seal part 11 Serrated gather

Claims (4)

[Claims] 1. A packaging bag having a back seal portion extending vertically on a back surface thereof, wherein at least one edge of the back seal portion is provided with serrated gathers continuously extending from an upper end to a lower end. Packaging bag. 2. The packaging bag according to claim 1, wherein the packaging bag is a pillow type packaging bag. 3. The packaging bag according to claim 1, wherein the packaging bag is a gusset type packaging bag. 4. A continuous-length plastic laminate film is provided, and the plastic laminate film is cut by a cutting blade having a serrated blade in a direction orthogonal to the flow direction of the film, and at least one side edge of the cut plastic laminate film is cut. Form a serrated gather, bend and mold the cut plastic laminate film so that both ends are abutted, heat-seal the abutted joint ends to form a tubular portion having a back seal portion, A method of manufacturing a packaging bag, characterized by heat-sealing an open end of a tubular portion.