JPH05310255A - Bag made of plastic film - Google Patents

Abstract

PURPOSE:To provide a bad made of plastic film with an unsealing means, which is obtainable at a low cost and less liable to damage. CONSTITUTION:The subject relates to a bag produced from a plastic film by fusion cutting at right angles to a turnover fold and at prescribed intervals and in a manner of forming at one end an opening 2 which is to be sealed. A cutting thread 3 in the form of a thread is fixed to the bag on the inner side either on the turnover line 1a or in parallel with the turnover line. A pull- tab 5 in which one end of the cutting thread 3 is held is formed in the front and back sides of the plastic film by perforations 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic film bag such as a plastic film envelope.

[0002]

2. Description of the Related Art Conventionally, as the envelope, a plastic film envelope having an opening to be sealed at one end by fusing both sides of a folded portion has been put into practical use. . In this envelope, the items to be sent are put in through the opening, and the opening is sealed by heat bonding or adhesive. When opening, the opening or the opposite part is cut with scissors, which makes the opening work troublesome. Met.

As a means for opening the envelope, there is a paper envelope in which a thread is sewn on the fold-back line of the lid and one end of the thread is pulled to open the envelope. Need to be attached to the back of the envelope with a sticker,
Not only is the manufacturing of the envelope cumbersome, but the thread portion exposed from the envelope is caught by another envelope or the like, causing the seal to peel off. Therefore, an object of the present invention is to provide a plastic film bag which can be manufactured at low cost without exposing the opening yarn on the bag surface even though the opening yarn is used.

[0004]

In order to achieve the above-mentioned object, the present invention provides a plastic film bag having an opening to be sealed at one end, which is melt-fused at a predetermined interval at right angles to the folding part and has a folding line. Or parallel to the fold line,
The thread-shaped cutter member is fixed to the inside of the bag, and a knob portion including the thread-shaped cutter member is formed on the front and back plastic films by perforation. The thread-shaped cutter member may be a different material composite thread that can be heat-bonded to the plastic film, or the surface of the thread-shaped body may be coated with coagulated glue.

[0005]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a view in which a plastic film bag A according to the present invention is applied to an envelope, in which 1 is a meltable thermoplastic plastic film a, for example, a polypropylene film, which is folded back in two and is predetermined at a right angle to a folding line 1a. It is an envelope body in which an opening 2 is formed at one end by fusing with a fusing blade 10 described below at intervals.

Reference numeral 3 denotes a thread-like cutter member, which is, as shown in FIG. 2, a polypropylene thread 4a of the same quality as the plastic film a and a twisted-twisted thread in which two polyester threads 4b and 4b having a higher melting temperature than polypropylene are twisted. Along the folding line 1a of the envelope body 1, the inside of the bag is heat-bonded. In this case, the plastic film a and the polypropylene thread 4a are heat-bonded to each other, but the other polyester thread 4b has a high melting temperature and remains a filament.

As described above, the perforations 5 are substantially diagonally perforated so that the end portion 3a of the filamentous cutter member 3 is included in one side portion of the envelope body 1 to which the filamentous cutter member 3 is attached.
It is a knob portion formed by providing.

Next, a method of using the plastic film envelope having the above construction will be described. First, the item to be sent is put through the opening 2 of the envelope A, and the opening 2 is sealed by heat sealing or the like for use. The opening 2 may be provided with a pressure-sensitive adhesive and a release paper (both not shown) on the side where the front and back plastic films are protruded in a stepped manner (neither is shown), and the protruding piece may be bent and sealed with the pressure-sensitive adhesive.

On the other hand, in order to open the envelope A, the knob portion 5 formed by the perforations 6 is cut off along the perforations 6, and the one end portion 3a of the filamentous cutter member 3 is fixed to the knob portion 5. Therefore, the knob portion 5 can be easily cut and opened by separating it from the envelope A as shown by the phantom line in FIG.

In the above-mentioned embodiment, the twisted yarn was explained as the filament cutter member 3, but the present invention is not limited to this, and it has a blended yarn containing polypropylene and a core such as polyester yarn inside, and its outer periphery is covered with polypropylene cotton. It may be a covering thread or a thread tape obtained by cutting a laminated film of a polyester film and a polypropylene film.

In short, the thread-shaped cutter member 3 may be made of the same material as the plastic film a, or a different material composite thread made of a material having a higher melting temperature than the plastic film a, as long as it can be fused. Further, the plastic film a is not limited to the polypropylene film and may be a polyethylene film. In this case, the different material composite yarn is
It may be made of polyethylene thread, polyethylene cotton, polyethylene film or the like and a material having a higher melting temperature than polyethylene.

Next, a method for manufacturing the plastic film bag of the present invention will be described. As shown in FIG. 3, the roll-shaped polypropylene film a is folded back at the center of the width and conveyed in the longitudinal direction. The high melting point filamentous material in the filamentous cutter member 3 is fixed to the film a by sandwiching the filament in the conveying direction and pressing it with the heat roll 7 (see FIG. 4). Then, both the films a are melt-cut together with the filament cutter member 3 by a melt-cutting blade 10 described below, which is orthogonal to the transport direction, to form an envelope A having an opening 2. In addition, 8 is a bobbin of the filamentous cutter member 3, and 9 is a yarn path reel.

By the way, as shown in FIG. 3, the fusing blade 10 includes a blade body 11 for fusing the film a and a blade body 1.
1 projecting obliquely to one side end side and a large number of needle-shaped bodies 1 on the lower end edge.
The knob forming portion 12 having the number 3 is provided. Since the fusing blade 10 has the above-described configuration, if the film a is fused at a predetermined interval, the tab forming portion 12 automatically forms the perforated triangular knob portion 5.

Although the filamentous cutter member 3 is provided on the fold line 1a of the envelope A in the above embodiment, it may be provided in parallel with the fold line 1a as shown in FIGS.
In this case, the fusing blade 10 may have a triangular shape as shown in FIG. The needle-shaped body 13 of the knob forming portion 12 shown in FIG. 6 is not provided at a portion intersecting with the thread-shaped cutter member 3 so that the thread-shaped cutter member 3 is not cut. Therefore, the knob forming portion 12 may have a two-divided structure so as to sandwich the filamentous cutter member 3.

In each of the above-mentioned embodiments, the thread-shaped cutter member 3 has been described as being heat-sealed on the plastic film a. However, heat-sealing may be performed by using a resin thread capable of being melted and coated with a coagulated glue. Instead, it may be fixed between the plastic films a.

[0016]

As is apparent from the above description, according to the present invention, the thread-like cutter member is provided between the two plastic films forming the bag. One end of the thread-like cutter member is opened before opening. Since it is fixed to the knob part that is integrally formed with the bag at the perforation, it is not necessary to fix one end of the thread-shaped cutter member to the surface of the bag with a seal as in the past, and it is formed at the same time when fusing. Because it is cheap. Also, since the thread cutter member is not exposed outside the bag, it is not only smart in appearance, but also the thread cutter member is pulled by an object during use and accidentally partially opened or the seal peels off. There is nothing to do. Furthermore, since the thread-shaped cutter member is fixed to only one side of the plastic film, it is possible to accommodate the enclosed material up to the bottom of the bag and to prevent the enclosed material from being damaged when opened.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of a plastic film bag according to the present invention.

FIG. 2 is a cross-sectional view showing an example of a thread-shaped cutter member.

FIG. 3 is an explanatory view showing a method for manufacturing a plastic film bag according to the present invention.

FIG. 4 is a diagram showing a relationship between the bag of FIG. 1 and a filamentous cutter member.

FIG. 5 is a front view showing a second embodiment of the plastic film bag according to the present invention.

6 is a diagram showing the relationship between the bag of FIG. 5 and the thread-like cutter member.

FIG. 7 is a perspective view of a fusing blade used for the bag of FIG.

[Explanation of symbols]

A ... bag, a ... plastic film, 1 ... envelope body, 1
a ... folded line, 2 ... opening, 3 ... filament cutter member, 3
a ... edge, 5 ... knob, 6 ... perforation, 7 ... heat roll, 10 ... fusing blade, 11 ... blade body, 12 ... knob forming section, 13 ... needle-shaped body.

Claims (3)

[Claims] 1. A plastic film bag having an opening to be hermetically sealed at one end, which is melted and cut at a right angle to the folded-back portion, and a thread-like cutter member is provided inside the bag on or parallel to the folded-back line. As well as sticking
A plastic film bag made by forming perforations on the front and back plastic films with the thread-like cutter member. 2. The plastic film bag according to claim 1, wherein the thread-shaped cutter member is a different material composite thread including a thread-shaped body capable of being heat-bonded to the plastic film. 3. The plastic film bag according to claim 1, wherein the thread-shaped cutter member is a thread-shaped body coated with a coagulant glue.