JPH0431941B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a plastic film sealed bag with excellent opening properties, particularly for storing sauces, jams, medicines, etc.
This invention relates to an easy-to-open, sealed bag for storing, transporting, and storing liquid, semi-liquid, powder, or powdery contents that would be difficult to recover if the bag were torn.

[Conventional technology]

In recent years, sealed bags made of plastic film are lightweight, can change shape depending on the situation, and can be filled and sealed continuously, so their field of use is expanding. In particular, sealed plastic bags are used to transport semi-liquid industrial food materials such as sauces, jams, bean paste, and salads, but it is the contents that are difficult to dispose of if spilled. A durable material is used to prevent it from tearing, and the sealing part is fused or glued to maintain sufficient peel strength.

Therefore, when opening the package, it is necessary to use a conventional opening method that does not use a knife, such as Japanese Utility Model Application Publication No. 57-37871, Publication of Utility Model Application No. 188663/1983, or Publication of Utility Model Application No. 59-1989.
V in one place of the edge line disclosed in Publication No. 99949 etc.
A method of providing a letter-shaped or I-shaped notch has been proposed.

Japanese Utility Model Application Publications No. 57-117337 and Japanese Utility Model Application No. 60-99270 disclose techniques for creating broken line perforations in order to open sealed bags made of materials that are difficult to tear.

[Problem that the invention seeks to solve]

However, Utility Model Application No. 57-117337 and Utility Model Application No. 60
When we actually tried the method described in Publication No. 99270 and the method of making V-notches and I-notches, we found that the film did not tear in the direction of force applied when opening the package, and as shown in Figure 4, Tearing occurred frequently. Furthermore, it has been found that bags that tear in a distorted manner as shown in FIG. 4 commonly have a large tearing resistance when tearing begins.

The inventor investigated the cause of this phenomenon, and as a result of stretching the film in the vertical direction and simultaneously stretching it in the horizontal direction during the film manufacturing process, as shown in FIG. It was found that the orientation was not in the correct horizontal direction, but in a distorted arc shape as shown by line 13.

Therefore, the distortion is large at the edges of the film, and even though it is called horizontal stretching, it is actually stretching in the diagonal direction.Even if a sealed bag is manufactured using such a film material, when it is pulled, both the front and back sides will be stretched. The tear runs along the original orientation direction of the film, resulting in a sealed bag that can be torn in an undesired direction as shown in FIG. Therefore, there was a need for a sealed bag that could be torn in a direction perpendicular to the edge line of the bag, with both the front and back films aligned when the bag was opened.

[Means of problem solving]

The present invention aims to solve the above problems,
The structure is a sealed bag made of a single-layer or multi-layer film having a stretched plastic film whose front and back sides are oriented in opposite directions, with a tear-starting part provided at the fused part. When the package is opened by pinching, if the surface is distorted in the opposite direction to the letter ``H'', there is a sign indicating directly or indirectly that the right side should be pulled towards you and the left side should be pulled towards the back. do.

The plastic film according to the present invention may be a monolayer or a laminate of polyester, nylon, polypropylene, polyethylene, ethylene-vinyl acetate copolymer, etc., or a laminate of these and other materials such as paper, metal foil, etc. include.

High-strength films such as polyester, nylon, and polypropylene, which provide the most resistance when the bag is torn, are generally uniaxially stretched in the horizontal direction, or biaxially stretched in which the horizontal direction stretching ratio is greater than the vertical direction stretching ratio, as shown in Figure 3. The degree of distortion in the orientation direction, ie, the degree of orientation distortion, as shown in (a) is generally significant in high-strength films. Here, orientation distortion will be defined. When stretched horizontally, the molecules should be aligned perpendicular to the length of the film, but in reality, when a film is stretched, both ends are pulled strongly, but the tensile force applied to the center is not as strong as at both ends. , are arranged diagonally as shown in FIG. The deviation between this theoretical molecular alignment direction (in the case of horizontal axis stretching, the direction perpendicular to the length direction) and the actual molecular alignment direction is defined as orientation strain.

The present inventor has discovered that even if the film has such orientation distortion, if the relationship between the orientation distortion direction on the front and back sides and the pulling direction is controlled, the front and back films can be aligned in the direction perpendicular to the edge line of the bag. The present invention was completed by discovering that it can be torn.

To tear a bag, hold it with both hands and pull one hand toward you and the other toward the back. For example, if you forcefully pull your right hand toward you, toward the surface, the orientation distortion of the surface film will be If the bag is in the opposite direction, the front and back films can be aligned and the bag can be torn in a direction perpendicular to the edge line where the bag started to be torn. Moreover, in this case, the tearing resistance at the start of tearing is also extremely small.

This relationship will be explained more specifically. Figure 5 is 2
This is the surface of a sealed bag with a surface orientation distortion shown in .
Therefore, the back surface has an orientation strain opposite to the front surface. The bag is not particularly limited, and may be of a four-side seal type, a pillow type, or a three-side seal type such as an envelope-type bag, as long as the orientation distortion on the front and back sides is exactly opposite. As shown in FIG. 5, there are four possible ways to tear such a bag: tearing from side a, tearing from side b, tearing from side c, and tearing from side d. When tearing from side a, a mark 6a is provided at the tear start point. In other words, instruct them to pull their left hand towards them and their right hand towards them. When tearing from side b, a mark 6b is provided at the tearing start point. In other words, instruct them to pull their right hand towards them and their left hand towards them. Similarly, when tearing from sides c and d, displays 6c and 6 shown in FIG.
By tearing according to d, the front and back films can be torn in parallel with small resistance.

FIG. 6 shows the case of a bag having an orientation strain opposite to that of FIG. That is, this is a case where a sealed bag is manufactured using the opposite part of the original fabric. In this case as well, there are four possible ways of breaking: a method of breaking from side e, a method of breaking from side f, a method of breaking from side g, and a method of breaking from side h. In this case as well, displays 6e and 6 respectively
By tearing according to f, 6g, and 6h, the front and back films can be torn in parallel with small resistance.

The tear initiation part according to the present invention is the above-mentioned V notch, I
Tear resistance can be improved by providing a group of minute scars along the edge line of the guiding part or fused part by perforation as shown in Figure 1, and cutting from any part where the group of scars are provided. Includes measures taken to facilitate tear initiation in large bags.

Labeling on bags can be done by printing arrows or letters on the bag, as shown in Figures 1, 2, 5, and 6, by locally painting, by changing the color tone on the front and back, or by adding patterns. The pulling direction may be indicated implicitly by changing the tension direction, or when a plurality of bags are stored together, the direction may be indicated only on the outer packaging. Alternatively, other materials such as film pieces or paper pieces may be attached in the direction of tension. Further, when a tear initiation part such as a fine scar is provided over the entire edge line, it is preferable to provide the indication over the entire vicinity of the fused part. In short, it is only necessary to provide a means for directly or indirectly making the consumer understand whether to pull his or her right hand or left hand forward or backward when pinching the end of the bag and starting to tear it.

Sealed bags can be used as four-sided sealed bags, three-sided sealed bags, pillow-type bags, gassho-stick bags, envelope-stick bags, stand-up bags, etc. The peel strength of the seal portion is preferably equal to or greater than the tear propagation strength of the film material to prevent the contents from spilling due to tearing during transportation or storage.

[Effect]

In the present invention, the horizontal orientation of the film, which is generally called a stretched film, is actually arc-shaped,
Because the edges are extremely diagonally oriented, the bag will tear in an undesired direction even if you guide the tearing direction in advance, but if you control the orientation and pulling direction correctly, the bag will tear in the intended direction. It was completed after discovering the fact that it can be broken accurately. The reason for this is not clear, but if the orientation distortions on the front and back sides are opposite to each other, and the front film is oriented in the opposite direction to the letter “◯”, you can either pull your right hand toward you or push your left hand backwards. If the front film is oriented in the cross-shaped direction, you can pull your left hand toward you, or
Alternatively, you can just push your right hand backwards, and if you apply force in the opposite direction, it will definitely break as shown in Figure 4.

〔Example〕

FIG. 1 is a perspective view of one embodiment of the invention.
1 is a sealed bag, which has a front orientation distortion 2 shown by a solid line and a back orientation distortion 3 shown by a broken line in the figure. 4 is the gassho pasting fusion part on the back side, 5 is the lower fusion part, 6
is the upper fused part. For the upper fused portion 6, the unsealing portion 7 is shallowly fused, the remaining portion including the gassho pasting fused portion 4 is deeply fused, and perforations 8 are provided in the deep fused portion. Perforation 8
was arranged so that its extension line was located at the non-fused portion of the opening 7. 9 is an indication printed on the outside of the perforation 8 on the front surface to indicate the tearing direction; in this example, if it is pulled toward the front, the orientation distortion on the front and back is canceled out, the front and back films are aligned, and the tear direction is indicated at the perforation 8. It breaks with light resistance in the direction of the extension line.

In this example, the bag contains 2.5 kg and uses the edge of the original film made by laminating polyester film and low-density polyethylene film and has a tear propagation strength of 75 g cm/cm. The peel strength of the sealed part is JIS It was measured according to Z 1707 and had a width of 5 kg/15 mm.

Figure 2 shows the peripheral fused portion 11 of a four-sided sealed bag.
This is an embodiment in which a V-notch is provided at one end. Since the orientation direction of the film is the same as in Figure 1,
A V-notch 10 was provided at one end, and an indication 9 consisting of the words "in front" and an arrow was printed on the outside of this V-notch (upper side in FIG. 2).

〔Effect of the invention〕

According to the present invention, even if the sealed bag is made of a high-strength film with a large horizontal stretching orientation strain, it can be reliably sealed by arm or hand force in the direction perpendicular to the edge line of the fused part where the tear initiation part is provided. Can be opened.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a sealed bag showing the orientation direction of the front and back films, Fig. 2 is a plan view of a four-sided sealed bag, Fig. 3 is a plan view showing the orientation distortion of the original film, and Fig. 4 This figure is a perspective view showing how the bag of FIG. 2 is torn when it is pulled in the wrong direction, and FIGS. 5 and 6 are surface views of the sealed bag illustrating orientation distortion and the direction in which the bag is torn. In the drawings, 1 is a sealed bag, 2 is a front orientation strain,
3 is back orientation distortion, 4 is gassho pasting fused area, 5 is lower fused area, 6 is upper fused area, 7 is unsealed area, 8 is perforation, 9 is indicated, 10 is V notch, 11 is surrounding area The fused part, 12 is the original fabric, and a to h are the sides that will become the tearing start part.

[Claims]

1 A transparent or translucent surface layer, a hidden pattern ink layer applied to the back side of this surface layer, a solid ink layer applied to the back side of the surface layer covering the hidden pattern ink layer, and a solid ink layer It consists of a sealing layer applied to the back side and a sealing layer bonded to the sealing layer, and the hidden pattern ink layer and solid ink layer are visually contrasting when viewed from the surface layer side. The interlayer bonding force of any one of the combinations of the surface layer and the hidden pattern ink layer, the hidden pattern ink layer and the solid ink layer, and the surface layer and the solid ink layer is a seal. A composite film seal structure characterized in that the bonding force is smaller than that between the adhesive layer and the sealed layer. 2. The composite film seal structure according to claim 1, wherein the hidden pattern ink layer is made of transparent ink, and the solid ink layer is made of colored ink. 3. The composite film seal structure according to claim 1, wherein the hidden pattern ink layer and the solid ink layer are made of ink of the same color. 4. The composite film seal structure according to any one of claims 1 to 3, wherein the surface layer, the sealing layer, and the sealed layer are made of plastic.