JPH03301B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention is applicable to liquids such as oil, vinegar, soybean oil, etc.
The present invention relates to a film for packaging bags that is used to package solid objects, powders, etc., and makes it easy to take out the contents. (Prior art) For example, it is attached to lunch boxes, instant noodles, etc.
Liquid-filled bags containing liquid seasonings such as soybean oil and sauce are generally made by heat-sealing a long film with at least one thermoplastic synthetic resin layer and enclosing the seasonings inside the bag. , the removal of the liquid seasoning from the liquid-filled bag is as follows:
In most cases, the bag is torn from a V-shaped or linear notch or slit provided in at least one part of the heat-sealed part of the bag, and the seasoning filling space of the bag opened by this tearing. This is done by forcing the liquid out of the seasoning outlet. This also applies to packaging bags for enclosing foods and other items. (Problem to be Solved by the Invention) By the way, these notches and slits are generally formed during the process of sealing liquid seasonings and other substances into the space regenerated by heat sealing, so they do not last long. Users of shaku film must separately prepare dedicated notch means and slit forming means that are controlled to operate in synchronization with the heat sealing machine, which reduces equipment costs and running costs for bag making equipment. There was a problem that I had to worship it quite a bit. For this reason, suppliers of films for packaging bags are looking for new products that solve the above-mentioned problems, in other words, do not require the user of long films to prepare a cutter or the like, and can easily open packaging bags. There is a strong demand for the development of new films. Therefore, attempts have been made to solve the above-mentioned problems by, for example, providing slits at the ends of the long film in the width direction, which are spaced apart from each other in the length direction, and which reach the ends of the long film in the width direction. Long films have been proposed. However, such long films are generally wound on paper tubes with a length of 500 m to 1000 m and provided to long film users.
When winding the long film onto a paper tube, a tensile force of 5 to 20 kg per unit width is applied to the long film in order to wind it properly. Therefore, when winding the film onto a paper tube, the above-mentioned long film in which a slit reaching the edge is provided at the end portion in the width direction of the film, the portion near the starting end of the slit at the end portion in the width direction of the film is removed. Since stress is concentrated on the film, even if a slight external force is applied to the film, a stress greater than the tear resistance of the film is likely to be generated in the vicinity of the slit starting point, causing the film to easily break. There is. This is almost the same even when a long film wound on a paper tube without being broken is continuously fed to a heat sheet machine. The present invention advantageously solves the problems of the prior art, and is easy to tear and does not break even when the long film is wound onto a paper tube and unwound. An object of the present invention is to provide a packaging film that is easy to handle. (Means for Solving the Problems) The film for packaging bags of the present invention has the feature that at least one end portion in the width direction of the long film provided with a thermoplastic synthetic resin layer is spaced apart in the length direction or Linear flaws are provided, and the terminal ends of these points or the linear flaws on the edge side in the width direction of the long film are located inward in the width direction of the long film. (Function) This long film for packaging bags has scratches spaced apart in its length direction at its widthwise end portions,
The end of the long film with these flaws on the edge side in the width direction is located inward in the width direction from the edge in the width direction of the long film, more preferably 0.3 mm or more inward from the edge in the width direction, and Since a continuous portion of the film is interposed between the widthwise end edge of the long film and the terminal end on the widthwise end edge side of the long film with flaws, winding and unwinding of the long film on the paper tube is facilitated. Even when returning the film, the long film will not break from the ends of the flaws. To open the bag formed by heat-sealing this long film, simply tear the continuous part of the long film interposed between the end of the flaw on the edge of the bag, and then Since the bag can be easily torn along the flaws, it can be torn with approximately the same force as conventional bags. (Example) The present invention will be described below based on illustrated examples. FIG. 1 is a plan view showing an embodiment of the present invention and an enlarged view of a part thereof, in which 1 is a long film for a packaging bag, and 2 is an end portion in the width direction of the long film. It shows the flaws made in each. The long film 1 for packaging bags is made of a thermoplastic synthetic resin film, preferably a laminated film,
The laminated structure can be, for example, nylon + polyethylene + ethylene vinyl acetate, polyethylene terephthalate + polyethylene + ethylene vinyl acetate, polypropylene + polyethylene, etc. from the outer layer side. In addition, when opening the bag formed by heat-sealing such a long film, at least one layer of the above-mentioned laminated structure is added in order to reduce tearing resistance and ensure smooth tearing in an almost direct shape. It is preferable to use a uniaxially or biaxially stretched film. On the other hand, in this example, the linear flaw 2 is
As clearly shown in FIG. 1b, they are formed along one end portion 3 in the width direction of the long film 1 for a packaging bag at intervals in the length direction. These flaws 2 where the terminal end 2a on the widthwise end portion side of the long film is located inward from the end portion 3 in the width direction of the long film 1.
The length L and depth shall be selected in relation to the width W of the film and the film material, and the depth may range from a slight cut from the film surface to a depth equal to the film thickness, i.e., a complete cut. You can choose from a variety of options, up to the most elaborate. In addition,
Similarly, the distance between the scratches can be appropriately selected. First, the distance between the terminal end 2a of 2 and the end portion 3 of the long film provided with the flaw 2 is positioned inward in the width direction of the long film by a predetermined distance D, more preferably 0.3 mm or more. By this, a continuous part of the film is interposed between the terminal end 2a of the flaw 2 and the end portion 3, so that the long film for bags is not flawed when the long film for bags is wound around the paper tube and unwound. 2 to prevent it from breaking. Note that it is advantageous to form the flaw 2 at a predetermined position on the long film 1 for bags using a special cutting tool having a cutting edge substantially equal to the length L of the flaw 2, and to form the flaw 2 at a predetermined position. It is preferable to form the flaws when cutting the starting material into a long film for a bag of a predetermined width. In this example, the flaws 2 are formed only along one portion 3 of the long film, but it goes without saying that they may be formed on both side end portions 3 and 4. Even if the film for packaging bags constructed in this way is wound or unwound on a paper tube under the action of a constant tension,
The film does not break, and even if it is formed into a bag by heat sealing, it can be easily torn from the flawed part. However, if the length L of the flaw 2 becomes longer than necessary, for example L = 6 mm, when the cutting tool is pressed against the long film 1 to form a flaw, the length of the long film that comes into contact with the cutting tool Since a tensile force is applied locally to the portion, the continuous portion of the film located between adjacent flaws in the longitudinal direction of the long film is stretched and plastically deformed. However, since the portion that extends in this way is restrained from moving in the in-plane direction of the film by other portions of the long film, it protrudes in the out-of-plane direction. Therefore, winding a long film for bags with end portions protruding outward in this way on a paper tube to a length of 500 to 1000 m is difficult to achieve by winding a long film with protrusions under the action of a constant tension. This is equivalent to winding a long film, and this causes tensile and shearing forces to act between the protruding part and the flat part, which may cause wrinkles in the film or damage between the central part of the long film and its end parts. The longitudinal length of the film differs between
A so-called high edge portion 5 occurs, which causes various inconveniences during the next process, that is, loading into a heat sealing machine, making it difficult to obtain a satisfactory product. Therefore, in another embodiment of the present invention shown in FIG. 2, two or more double rows of flaws are formed along the end portion of the long film and spaced apart in the length direction,
The length l of each flaw is made shorter than the length L of a single row of flaws. The structure is such that the tensile force is reduced and the continuous portion of the film between the longitudinally spaced flaws is not substantially subjected to plastic deformation. Of course, it is located on the end part side of the long film.
The terminal end of the side end portion of the flaw and the side end portion of the long film shall be separated by a predetermined distance D, preferably 0.3 mm or more. In addition, the length l of each double row flaw is
Although the length L of a single flaw is shorter than the length L of a single flaw as in the example shown in FIG. It can be done easily with almost no changes. By the way, a laminated film A consisting of a uniaxially stretched nylon film with a thickness of 15 μm and a polyethylene film with a thickness of 60 μm, a polyethylene terephthalate film with a thickness of 12 μm, a polyethylene film with a thickness of 15 μm, an aluminum film with a thickness of 7 μm,
Tables 1 and 2 show the results of experiments conducted on laminated film B made of polyethylene film with a thickness of 20 μm.
are shown respectively. However, the winding length of each laminated film A and B was 1000 m.

【table】

【table】

[Table] As is clear from Tables 1 and 2, by leaving a distance D of 0.3 mm or more between the end of the long film and the end of the flawed long film on the widthwise edge side, a constant tension can be maintained. When winding or unwinding a long film between sheets under the action of
It can be seen that even when a long film is attached to a heat sealing machine, the film does not break. Moreover, the bag body formed by heat sealing this long film can be made by simply tearing the continuous part of the film interposed between the end of the widthwise edge of the long film and the end of the flaw. It can be opened in the same way. In another embodiment of the present invention shown in FIG. 2c, unlike the embodiment shown in FIG. The film is spaced apart in the longitudinal direction of the film, and its function is similar to that of the long film of the present invention described above. Note that the present invention is not limited to these examples; for example, the flaws may be bent in a chevron shape instead of a straight line, or may extend at a certain inclination with respect to the edge in the width direction of the long film. can be taken as a thing. Furthermore, these flaws may be provided not only at one widthwise end portion of the long film, but also at both end portions of the film, and various modifications are possible within the scope of the claims. (Effects of the Invention) As described in detail above, according to the present invention, flaws are provided at at least one widthwise end portion of a long film for a packaging bag at intervals in the length direction, and these flaws are removed from the film. Since the terminal end on the edge side in the width direction is located inward in the width direction of the film, even when the long film is wound around the paper tube or unwound, the long film does not break at the flawed part. Also, the film does not wrinkle. In addition, the film does not break even when loaded into a heat-sealing machine, so packaging bags can be formed efficiently using this film, and the packaging bag does not tear at the edges of the packaging bag. This allows the entire bag to be torn apart in the same manner as known packaging bags.

[Brief explanation of drawings]

Figures 1a and b are a plan view and an enlarged detailed view showing one embodiment of the present invention, respectively, and Figures 2a and b are a plan view and an enlarged detailed view thereof respectively showing another embodiment of the present invention. Figure 2c shows an enlarged detail of another embodiment of the invention. 1...Film for packaging bags, 2...Flaws, 2a...
...End of flaw, 2b...Start of flaw, 3,4...
Edge, 5... High ear part.

Claims (1)

[Scope of Claims] 1. Points or linear flaws spaced apart in the length direction are provided on at least one widthwise end portion of a long film provided with a thermoplastic synthetic resin layer, and the points or lines are formed at intervals in the lengthwise direction. A film for a packaging bag, characterized in that a terminal end of the flaw in the width direction of the long film is located inward in the width direction of the long film. 2. The end of the point or linear flaw on the widthwise end portion side is 0.3 mm from the widthwise edge of the long film.
2. The packaging bag film according to claim 1, wherein the film is positioned inward in the width direction by at least 1 mm.