JP6906283B2 - Packaging bag - Google Patents

Description

The present invention relates to a packaging bag.

Conventionally, packaging bags for packaging foods, cosmetics, beverages and the like have been known.

The packaging bag is formed in a bag shape by, for example, stacking two laminated films and adhering the edges by heat welding or the like. In such a packaging bag, the contents are filled from the unbonded portion of the edge, that is, the opening. After that, the opening of the packaging bag is adhered by heat welding or the like. In this way, a packaging bag containing the contents is manufactured.

Normally, when the contents are removed from the packaging bag, the packaging bag is opened by tearing it from a part of its edge. When the packaging bag is torn from a part of the edge of the packaging bag, an opening piece separated from the packaging bag body may occur.

The opened piece separated from the main body of the packaging bag brings various disadvantages in practical use of the packaging bag. For example, if an opened piece is generated when a packaging bag containing a raw material or the like is opened at a manufacturing site or the like, the opened piece may be mixed in the product. Further, in daily life, if an opened piece is generated when a packaging bag containing food or the like is opened, the disposal of garbage becomes complicated and it may cause littering.

Therefore, there has been a demand for a technique for preventing the opened piece from being separated from the main body of the packaging bag.

Patent Documents 1 to 6 disclose a packaging bag having a tear start portion and a tear stop position.

In these documents, the tear stop position has cuts of various shapes. The shape of the notch mentioned in these documents is a convex shape (Patent Document 1) or a concave shape (Patent Documents 2, 3, and 5) toward the tear start portion, and intersects in the tear direction. There is a linear one (Patent Document 4). Further, as the shape of the notch, there is also one having a straight notch intersecting in the tearing direction and having circular hole-shaped notches at both ends of the straight line (Patent Document 6).

Japanese Unexamined Patent Publication No. 2014-101141 Japanese Unexamined Patent Publication No. 2013-224167 JP-A-2009-255959 Japanese Unexamined Patent Publication No. 2007-276823 Japanese Unexamined Patent Publication No. 2000-281090 Japanese Unexamined Patent Publication No. 2000-296859

As described above, as a technique for preventing the opening piece from being separated from the main body of the packaging bag, it is known to provide notches of various shapes at the tear stop position.

However, depending on the direction of the force applied when tearing the packaging bag, the amount of force applied, etc., it may not be possible to sufficiently stop the tearing with the conventional notch.

Therefore, there is a demand for a packaging bag that can more reliably stop tearing at the tearing stop position when opening the package.

An object of the present disclosure is to provide a packaging bag in which the opening piece is not separated from the packaging bag when the packaging bag is opened.

<Aspect 1>
A packaging bag that is opened by tearing
The tearing start point portion that is the starting point for starting the tearing, and the tearing stop position defined as the position where the tearing should be stopped.
With
The tear stop position has a notch and
The notch has a convex shape toward one side and the other side of the two parts of the packaging bag separated by a virtual tear straight line connecting the tear start point portion and the tear stop position, respectively.
Both vertices of the convex shape have an arc shape and
One of the convex ends of both is connected at the tear stop position, and the other of both convex ends is not connected.
The notch has the farthest portion farthest from the tear origin portion in the direction along the virtual tear straight line, and the slope of the tangent line of the farthest portion is perpendicular to the virtual tear straight line.
Packaging bag.
<Aspect 2>
The packaging bag according to aspect 1, wherein at least one of the convex shapes is on the opposite side of the tear starting point portion with respect to the tear stop position.
<Aspect 3>
The packaging bag according to aspect 2, wherein both of the convex shapes are on the opposite side of the tear starting point portion with respect to the tear stop position.
<Aspect 4>
The packaging bag according to any one of aspects 1 to 3, wherein the notch is symmetrical with respect to the virtual tear line.
<Aspect 5>
In aspect 2, one of the convex shapes is on the opposite side of the tear start point portion with respect to the tear stop position, and the other convex shape is on the tear start point portion side with respect to the tear stop position. The listed packaging bag.
<Aspect 6>
The packaging bag according to any one of aspects 1 to 5, wherein the portion where one of the ends of the convex shape is connected to each other is a straight line perpendicular to the virtual tear straight line.
<Aspect 7>
Of the notches, the end portion in the direction extending from the most distant portion of the convex shape to the side opposite to the tear stop position is the farthest portion and the tear stop position in the direction along the virtual tear straight line. The packaging bag according to any one of aspects 1 to 6, which is located between.
<Aspect 8>
The packaging bag according to any one of aspects 1 to 7, wherein the apex of the convex shape has a shape having a substantially semicircle having a radius of 1.0 mm or more.
<Aspect 9>
The packaging bag according to any one of aspects 1 to 8, wherein the contents are sealed inside, and the contents can be taken out by opening the package by tearing.

According to the present disclosure, it is possible to provide a packaging bag in which the opening piece is not separated from the packaging bag when the packaging bag is opened.

FIG. 1 is a schematic view of a packaging bag based on an embodiment of the present disclosure. FIG. 2 is a schematic view of a notch in a packaging bag based on an embodiment of the present disclosure. FIG. 3 is a schematic view of a notch in a packaging bag based on another embodiment of the present disclosure. FIG. 4 is a schematic view of a notch in a packaging bag based on still another embodiment of the present disclosure. FIG. 5 is a schematic view of a portion of a notch in a packaging bag based on yet another embodiment of the present disclosure. FIG. 6 is a schematic view of a notch in the packaging bag of each embodiment. FIG. 6A is a schematic view of a notch in the packaging bag of Example 1. FIG. 6B is a schematic view of a notch in the packaging bag of the second embodiment. FIG. 6C is a schematic view of a notch in the packaging bag of Example 3. FIG. 7 is a schematic view of a notch in the packaging bag of each comparative example. FIG. 7A is a schematic view of a notch in the packaging bag of Comparative Example 1. FIG. 7B is a schematic view of a notch in the packaging bag of Comparative Example 2.

Hereinafter, embodiments of the present disclosure will be described in detail. The present invention is not limited to the following embodiments, but can be variously modified and implemented within the scope of the gist of the invention.

The packaging bag of the present disclosure is a packaging bag that is opened by tearing. The packaging bag includes a tear starting point portion that serves as a starting point for starting tearing, and a tearing stop position defined as a position at which tearing should be stopped.

The tear stop position has a notch. The notch has a convex shape toward one side and the other side of the two parts of the packaging bag separated by a virtual tear straight line connecting the tear start point portion and the tear stop position, respectively. The vertices of both convex shapes have an arc shape. At the ends of both convex shapes, one is connected at the tear stop position and the other is not. Further, the notch has the farthest portion farthest from the tear starting point portion in the direction along the virtual tearing straight line. The slope of the tangent to the farthest part is perpendicular to the virtual tear line.

FIG. 1 is a schematic view of a packaging bag based on an embodiment of the present invention. In FIG. 1, the edge 20 of the packaging bag 10 is adhered to the packaging bag 10. Further, the packaging bag 10 has a storage portion 30, a tear start point portion 40, and a tear stop position 50. The accommodating portion 30 is a portion accommodating the contents. The contents in the storage portion 30 can be taken out by tearing the packaging bag 10 from the tear starting point portion 40 and opening it. Further, there is a notch 100 at the tear stop position 50.

Although not limited by the principle, the principle of action of the present invention is considered to be as follows.

In order to prevent the opened piece from being separated from the main body of the packaging bag when the packaging bag is torn, there is a method of making a notch at the tear stop position of the packaging bag.

However, even when such a notch is made, it is not possible to completely prevent the opened piece from being separated from the main body of the packaging bag. That is, there is a problem that the opened piece is separated from the main body of the packaging bag due to the tearing depending on the direction and strength of the tearing force.

In particular, when the notch has a convex shape toward the tear starting point side, the tear may resume from the end of the notch. It is considered that this is because the direction of the end of the notch is along the tearing direction. The end of the notch is considered to be more vulnerable to tearing than the rest of the notch.

Further, as a means for preventing tearing other than making a notch, it is conceivable to provide a hole at the tearing stop position by punching or the like. However, when holes are provided in the packaging bag by punching or the like, there is also a problem that punched hole pieces are generated and extra dust is generated during manufacturing.

Since the packaging bag of the present disclosure has a notch having a certain shape at the tear stop position, it becomes difficult for the opened piece to be separated from the packaging bag when the packaging bag is opened. Further, the packaging bag of the present invention is excellent in that not only does it not generate an opening piece at the time of opening, but also it does not generate a punched hole piece by punching a hole at the time of manufacturing, so that excess dust can be prevented from being discharged. There is.

《Tearing starting point》
The tearing starting point portion is a portion serving as a starting point for starting tearing. The tear starting point portion is a portion for starting the opening of the packaging bag by tearing, and may be processed for facilitating the tearing of the packaging bag, for example, a notch or a notch.

It is preferable that the packaging bag of the present disclosure does not have another tear starting point portion on the opposite side of the tear starting point portion with respect to the tear stop position.

《Tearing stop position》
The tear stop position is a position defined as a position where the tear should be stopped. The tear stop position has a notch.

The tear stop position is the position where the tear is scheduled to be stopped. The tear stop position does not always coincide with the actual tear stop position.

《Cut》
The notch has a convex shape toward one side and the other side of the two parts of the packaging bag separated by a virtual tear straight line connecting the tear start point portion and the tear stop position, respectively. The vertices of each convex shape have an arc shape, and one of the convex end portions is connected to each other at the tear stop position, but the other end portion is not connected to each other. Further, the notch has the farthest portion farthest from the tear stop position in the direction along the virtual tear straight line, and the slope of the tangent line of this farthest portion is perpendicular to the virtual tear straight line.
The notch may be symmetric with respect to the virtual tear straight line or point symmetric with respect to the tear stop position.

<Virtual tearing straight line>
The virtual tear straight line represents a portion to be torn when the packaging bag is torn from the tear starting point portion by a virtual straight line. The virtual tear line does not need to be explicitly present on the packaging bag.

<Convex shape>
The vertices of both convex shapes have an arc shape. When the apex of the convex shape is square, when tearing the packaging bag, the tearing force is applied to the corner of the convex shape, and it becomes easier to start tearing from the corner. Can be suppressed.

Further, it is preferable that the apex of the convex arc has a shape having a substantially semicircle having a radius of 1.0 mm or more. The radius of the substantially semicircle may be 1.0 mm or more, 2.0 mm or more, or 3.0 mm or more. Here, the "substantially semicircle" includes a shape similar to a semicircle. Therefore, for example, the vicinity of the apex of the convex arc may be a semicircular shape, a half shape of an ellipse, a parabolic shape, or the like. When the vicinity of the apex of the convex arc is not a semicircle, the "radius" is the radius of the largest circle inside the convex and tangent to the apex.

One of the convex ends of both cuts is connected at the tear stop position, but the other of the ends is not. It is preferable that one of the ends is smoothly connected to each other in a shape having no corners.

At least one of both convex shapes of the notch may be on the opposite side of the tear origin portion with respect to the tear stop position.

A notch in a packaging bag according to an embodiment of the present disclosure has both convex shapes on opposite sides of the tear origin portion relative to the tear stop position.

FIG. 2 is a schematic view of a notch in a packaging bag based on an embodiment of the present disclosure. In FIG. 2, the notch 100 has a convex shape 140 toward one side and the other side of two parts of the packaging bag separated by a virtual tear straight line 60 connecting the tear start point portion and the tear stop position 50, respectively. The apex of the convex shape 140 has an arc shape. Further, one end of each of the convex shapes 140 is connected to each other at the tear stop position 50.

Further, in FIG. 2, the two convex shapes 140 are on the opposite side of the tear start point portion with respect to the tear stop position 50, and the inclination of the tangent 115 of the farthest portion 110 farthest from the tear stop position 50 is virtual. It is perpendicular to the tear straight line 60. Although not shown in FIG. 2, the tear starting point portion exists on the virtual tear straight line 60 on the left side of each figure. Further, a shape in which the shape of FIG. 2 is tilted with respect to the virtual tear straight line 60 is also included in the scope of the present disclosure.

The notch shape of the packaging bag according to another embodiment of the present disclosure has both convex shapes on the tear start point side with respect to the tear stop position.

FIG. 3 is a schematic view of a notch in a packaging bag based on an embodiment of the present disclosure. In FIG. 3, the notch has a convex shape 140 toward one side and the other side of two parts of the packaging bag separated by a virtual tear straight line 60 connecting the tear start point portion and the tear stop position 50, respectively. The apex of the convex shape 140 has an arc shape. Further, one end of each of the convex shapes 140 is connected to each other at the tear stop position 50.

Further, in FIG. 3, the two convex shapes 140 are on the tear start point side with respect to the tear stop position 50, and the inclination of the tangent 115 of the farthest portion 110 farthest from the tear stop position 50 is a virtual tear straight line. It is perpendicular to 60. Although not shown in FIG. 3, the tear starting point portion exists on the virtual tear straight line 60 on the left side of each figure. Further, a shape in which the shape of FIG. 3 is tilted with respect to the virtual tear straight line 60 is also included in the scope of the present disclosure.

The notch shape of the packaging bag according to still another embodiment of the present disclosure has one convex shape on the opposite side of the tear starting point portion with reference to the tear stop position, and the other convex shape is based on the tear stop position. It is held on the tear starting point side.

4 (a) and 4 (b) are schematic views of a notch in a packaging bag based on other embodiments of the present disclosure, respectively. In FIG. 4 (a), the notch 100 has a convex shape 140 toward one side and the other side of the two parts of the packaging bag separated by the virtual tear straight line 60. Further, the end portion of one convex shape 140 near the tear starting point portion and the end portion of the other convex shape 140 far from the tearing starting point portion are connected to each other at the tear stop position 50. In FIG. 4B, the notch 100 has a shape in which the ends different from those in FIG. 4A are connected to each other.

The shape of the portion where one of the respective end portions of the convex shape is connected to each other, that is, the shape of the notch near the tear stop position preferably has a straight portion perpendicular to the virtual tear straight line. This is because the tear can reach the incision even if the actual tear progresses deviating from the virtual tear straight line and deviates upward or downward from the tear stop position.

Although not shown in FIGS. 4 (a) and 4 (b), the tear starting point portion exists on the virtual tear straight line 60 on the left side of each figure. Further, the shape in which the shapes of FIGS. 4A and 4B are tilted with respect to the virtual tear straight line 60 is also included in the scope of the present disclosure.

<Farest part>
The notch has the farthest part farthest from the tear stop position in the direction along the virtual tear straight line. The slope of the tangent line at the farthest part is perpendicular to the virtual tear straight line.

In the packaging bag based on the embodiment of the present disclosure, when the packaging bag is torn from the tear starting point along a virtual tear straight line and the tear reaches the tear stop position, the tearing force is applied to the farthest portion of the notch. When the convex shape of the notch has an arc shape and the tangent line of the farthest part of the notch has a shape perpendicular to the tearing direction, further tearing of the packaging bag can be suppressed more effectively.

<Terminal part>
The end of the notch on the side extending in the direction opposite to the tear stop position from the farthest portion is preferably located between the farthest portion and the tear stop position in the direction along the virtual tear straight line.

In general, further tearing of the packaging bag tends to proceed from the end of the notch. The packaging bag is pulled by extending the end of the notch inside the convex shape of the notch, that is, extending the end of the notch so that it is located between the farthest part and the tear stop position in the direction along the virtual tear straight line. The force applied at the time of tearing can be made less likely to be applied to the end portion of the notch, and the effect of further suppressing the tearing can be obtained.

In addition, the end of the notch, which has a convex shape on the opposite side of the tear start point with respect to the tear stop position and is located at a position extending from the farthest part farthest from the tear stop position, enters the inside of the convex arc. It is preferable to be. Since the notch has such a shape, when tearing the packaging bag, the tearing force is less likely to be applied to the end portion of the notch. This makes it easier to stop the tearing at the tearing stop position of the packaging bag.

The end portion of the notch extending from the farthest portion toward the inside of the convex shape is preferably arcuate from the viewpoint of making it easier to stop the tearing. The size of the arc at the end of the notch extending from the farthest portion toward the inside of the convex shape may have a radius of 0.5 mm or more, 1.0 mm or more, and 1.5 mm or more.

FIG. 5 is a schematic view of one convex portion of a notch in a packaging bag based on yet another embodiment of the present invention. In FIG. 5, the vicinity of the tear stop position 50 of one convex portion of the notch 100 has a straight line portion 160 perpendicular to the virtual tear straight line. Further, the end portion 150 of the notch at the position extending from the farthest portion farthest from the tear stop position of the convex shape 140 on the opposite side of the tear start point with respect to the tear stop position is the arc of the convex shape 140. It's inside. In FIG. 5, the other convex portion existing below the virtual tear straight line 60 in the figure is omitted. Further, although not shown in FIG. 5, the tear starting point portion exists on the virtual tear straight line 60 on the left side of each figure.

《Packaging bag》
The packaging bag is opened by tearing. The contents of the packaging bag can be enclosed inside, and the contents may be taken out by opening the packaging bag by tearing.

The packaging bag may have, for example, a bag-like structure in which a plurality of films, particularly two films, are superposed and the edges of the films are adhered to each other.

The packaging bag may be provided with a fragile line along at least a portion of the virtual tear line, which has a lower tear strength than the rest of the packaging bag. By providing such a fragile line, the tear can be guided to the tear stop position along the fragile line. Such a fragile line can be provided by, for example, a dotted line or a perforation.

As the film used for the packaging bag, for example, a laminated film in which a base material layer, a barrier layer, an intermediate layer, and a sealant layer are laminated in this order can be used.

Examples of the base material layer include polyolefins such as polyethylene (PE) and polypropylene (PP), polyesters such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), and polyamides such as 6-nylon and 6,6-nylon. , Polystyrene (PS), vinyl chloride (PVC), synthetic paper and the like.

The base material layer may be constructed using a stretched material. This stretching may be uniaxial stretching or biaxial stretching.

The thickness of the base material layer is not particularly limited, but in order to give the obtained packaging bag sufficient strength and good cutability, for example, it can be 7 μm or more, and can be 10 μm or more. preferable. The upper limit value can be 50 μm or less, preferably 30 μm or less.

The barrier layer is a layer having a function of suppressing the invasion of gas (particularly oxygen), moisture, and / or light from the outside world and protecting the contents.

Examples of the barrier layer include aluminum, silica, polyvinylidene chloride, polyvinyl alcohol, and the like.

The barrier layer may be used in the production of a laminated film used in the present invention as an independent film or foil, or is supplied in a state of being previously formed into a layer on one side or both sides of a suitable base film. The material may be used as it is. When the barrier layer is a layer formed on the base film, the base film may also serve as the above-mentioned base material layer or the later-described intermediate layer. Examples of the base film include a film made of polyethylene terephthalate, nylon, or the like.

The thickness of the barrier layer can be, for example, 1 μm or more, 3 μm or more, or 5 μm or more, for example, 10 μm or less, or 8 μm or less when the barrier layer is provided as an independent film or foil. When the barrier layer is provided as a layer formed on a base film, it can be, for example, 1 nm or more, 3 nm or more, or 5 nm or more, for example, 500 nm or less, 300 nm or less, or 200 nm or less.

Examples of the intermediate layer include polyethylene terephthalate, nylon, polypropylene and the like. The intermediate layer may be unstretched, uniaxially stretched or biaxially stretched.

The thickness of the intermediate layer can be, for example, 5 μm or more or 10 μm or more, and can be, for example, 40 μm or less or 20 μm or less.

As described above, the laminated material supplied as a barrier layer in a state of being previously formed in a layer on one side or both sides of the base film may be used as it is, and the base film may also serve as an intermediate layer. Laminated materials that can be suitably used in such cases include, for example, polyvinylidene chloride coat / biaxially stretched nylon, polyvinylidene chloride coat / biaxially stretched polyethylene terephthalate, aluminum vapor deposition / polyethylene terephthalate, and aluminum vapor deposition / biaxially stretched nylon. , Silica vapor deposition / biaxially stretched polyethylene terephthalate, silica vapor deposition / biaxially stretched nylon, polyvinyl alcohol / biaxially stretched polypropylene, polycarboxylic acid polymer / biaxially stretched nylon, metaxylene diamine-nylon composite film, and ethylene vinyl alcohol Polymer-nylon composite film and the like can be mentioned.

Examples of the sealant layer include thermoplastic resins such as low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), polypropylene (PP), and ethylene-acetic acid. Vinyl copolymers, ionomer resins, ethylene- (meth) acrylic acid copolymers, ethylene- (meth) acrylic acid alkyl ester copolymers, ethylene-propylene copolymers (EPM), polymethylpentene, polybutene, etc. Materials can be mentioned.

The thickness of the sealant layer can be, for example, 20 μm or more or 30 μm or more, and can be, for example, 80 μm or less or 70 μm or less.

The tear strengths of Examples 1 to 3 and Comparative Examples 1 and 2 were verified as follows.
<< Making a packaging bag >>
1. 1. Bag-making The packaging bags of Examples 1 to 3 and Comparative Examples 1 and 2 were made by a bag-making filling machine (VH-100 manufactured by Orihiro), and the contents were filled in the packaging bags.

Specifically, the packaging bag was made and the contents were filled as follows.

Two films laminated in the order of the base material layer, the barrier layer, the intermediate layer, and the sealant layer were laminated so that the sealant layer was on the inside. Next, the top and bottom portions of the stacked films were sealed. Subsequently, one side seal was made, and the contents were filled, and the other side seal was made. Finally, a pinnacle mold was used to punch out the outer shape of the sealed film and the notch at the tear stop position.

Specifically, the film used for bag making had the configuration shown in Table 1 below. In the table, "PET" indicates polyethylene terephthalate, "Al foil" indicates aluminum foil, "NY" indicates nylon, and "LLDPE" indicates linear low-density polyethylene.

2. Shape of the bag The packaging bags of Examples 1 to 3 and Comparative Examples 1 and 2 had the same shape as the packaging bag shown in FIG. 1 except for the shape of the notch portion. That is, the packaging bags 10 of Examples 1 to 3 and Comparative Examples 1 and 2 have a tear starting point portion 40 at the edge portion 20 and are notched at the tear stop position 50 defined as a position where the tear should be stopped. Had 100.

3. 3. Shape of cuts The cuts in the packaging bags of Examples 1 to 3 and Comparative Examples 1 and 2 were as shown in FIGS. 6 and 7, respectively. In addition, in FIGS. 6 and 7, the virtual tear straight line 60 is merely a virtual line and does not exist as a notch or the like in the actual packaging bag. Further, although not shown in FIGS. 6 and 7, the tear starting point portion exists on the virtual tear straight line 60 on the left side of each figure.

FIG. 6A is a schematic view showing the shape of the notch in the packaging bag of Example 1. In FIG. 6A, the notch has a pair of convex semicircular shapes outward to each other in a direction perpendicular to the virtual tear straight line 60. The ends of the semicircular shape near the tearing starting point are connected by a straight line.

FIG. 6B is a schematic view showing the shape of the notch in the packaging bag of the second embodiment. In FIG. 6B, the end portion of the notch has the same shape as the notch of the packaging bag of Example 1 except that the notch is inserted inside the convex shape.

FIG. 6C is a schematic view showing the shape of the notch in the packaging bag of Example 3. In FIG. 6C, the convex shape of the notch has a smaller radius of the convex semicircle as compared with the notch shape of the packaging bag of Example 2, and the entire notch shape is formed in the direction along the virtual tear straight line. The width is getting smaller.

FIG. 7A is a schematic view showing the shape of the notch in the packaging bag of Comparative Example 1. In FIG. 7A, the notch has a convex shape centered on the virtual tear straight line 60 in the direction from the tear stop position toward the tear start point portion.

FIG. 7B is a schematic view showing the shape of the notch in the packaging bag of Comparative Example 2. In FIG. 7B, the notch has the same shape as the notch of Comparative Example 1 except that the inclination with respect to the virtual tear straight line 60 is different.

The radius of the convex semicircle of the cuts of Examples 1 and 2 was 3.0 mm, and the radius of the semicircle of the portion entering the inside of the convex of Example 2 was 1.5 mm. Further, the radius of the convex semicircle of the notch in Example 3 was 1.5 mm, and the radius of the semicircle of the portion entering the inside of the convex shape was 0.75 mm. Further, in Examples 1 to 3, the portion where the convex shapes are connected to each other was a straight line of 6.0 mm. Table 2 shows the values of the convex shape of the cuts of Examples 1 to 3, the radius of the semicircle near the end portion, and the length of the straight portion.

<< Experiment 1: Tensile strength test >>
Five packaging bags of Examples 1 to 3 and Comparative Examples 1 and 2 were prepared. The tensile strength (N) of each packaging bag was measured as follows.

A straight line was cut with a cutter from the tear start part of the packaging bag to the tear stop position. Then, the opened piece and the main body of the packaging bag were sandwiched between chucks, and pulled at a speed of 300 mm / min using a tensile tester until the opened piece and the main body of the packaging bag were separated. Then, the maximum value of the tensile strength (N) from the beginning of the tension to the completion of the tension was measured.

<result>
The experimental results are shown in Table 3 below. The numerical values in Table 3 indicate the average value of the tensile strength (N) of each packaging bag.

With reference to Table 3, it can be seen that the packaging bags of Examples 1 to 3 have much higher tensile strength than the packaging bags of Comparative Examples 1 and 2.

Furthermore, Example 2 (average tear strength 28.72N) and Example 3 (average tear strength 19.16N) had much higher tensile strength than Example 1 (average tear strength 11.90N). .. In particular, Example 2 had a tensile strength of about 2.4 times or more that of Example 1.

In the cuts of Comparative Examples 1 and 2, the end portion of the cut is provided along the tearing direction. When the notch has such a shape, the pulling force applied when tearing the packaging bag is applied to the end of the notch. Since the end of the notch serves as the starting point for tearing the packaging bag, it is easily torn. Therefore, in the packaging bags of Comparative Examples 1 and 2, it is considered that the packaging bags were further easily torn from the end of the notch.

On the other hand, the packaging bags of Examples 1 to 3 have an arcuate notch that is convex in the direction perpendicular to the tearing direction, and the farthest portion of the notch is perpendicular to the virtual tearing straight line. When the notch has such a shape, the pulling force applied when tearing the packaging bag is applied to the curved portion of the notch. It is probable that the curved part of the notch was difficult to tear because it does not become the starting point of tearing unlike the end part.

Furthermore, the packaging bags of Examples 2 and 3 had much higher tensile strength than the packaging bags of Example 1. It is considered that this is because the end portion of the notch in the packaging bag of Examples 2 and 3 is separated from the farthest portion.

If the packaging bag is continuously pulled, the shape of the packaging bag is considered to gradually change due to the tension. The notch portion of the packaging bag also deforms according to the change in the shape of the packaging bag. When the end of the notch is close to the farthest part, the end of the notch becomes the farthest part facing the tearing direction due to the deformation of the notch of the packaging bag, and the packaging bag further starts from the end of the notch. Expected to be easily torn.

The end of the notch in the packaging bag of Examples 2 and 3 is separated from the farthest part of the notch. Therefore, it is considered that even if the notch portion of the packaging bag is deformed by tension, the end portion of the notch does not become the farthest portion. Therefore, the packaging bags of Examples 2 and 3 are considered to have high tensile strength.

Further, the packaging bag of Example 2 has a higher tensile strength than the packaging bag of Example 3, because the packaging bag of Example 2 has a larger convex shape, that is, the radius of the convex arc is larger. It is thought that this is the reason.

<< Experiment 2: Opening test >>
Five packaging bags of Examples 1 to 3 and Comparative Examples 1 and 2 were prepared. Each packaging bag was subjected to an opening test as follows.

Five testers were allowed to open one packaging bag each of Examples 1 to 3 and Comparative Examples 1 and 2, and the probability that the opened piece remained without being separated from the packaging bag body after opening was investigated.

<result>
The experimental results are shown in Table 4 below.

With reference to Table 4, in the packaging bags of Examples 1 to 3, there is a high probability that the opened pieces remain without being separated from the packaging bag main body. In particular, in Examples 2 and 3, when all the testers opened the package, the opened piece remained in the main body of the packaging bag. On the other hand, in the packaging bags of Comparative Examples 1 and 2, the probability that the opened piece remains without separating from the packaging bag body is very low, 20% in Comparative Example 1 and 0% in Comparative Example 2. ..

As described above, it can be seen that the cuts in the packaging bags of Examples 1 to 3 make it easier for the opened pieces to remain in the packaging bag body.

This result seems to reflect the difference in tensile strength shown in Table 3 above.

As described above, when the packaging bag of the present invention is torn by hand and opened, the tearing can be stopped more reliably at the tear stop position, and the opening piece is less likely to be generated at the time of opening, and excess dust is removed. Do not cause. Further, in the packaging bag of the present invention, a high tear stopping force can be realized only by providing a notch in the packaging bag without providing a hole. Therefore, the packaging bag of the present invention is excellent in that not only does it not generate an opening piece at the time of opening, but also it does not generate a punched hole piece by punching a hole at the time of manufacturing, so that excess dust can be prevented from being discharged. There is.

10 Packaging bag 20 Edge 30 Storage part 40 Tear start point part 50 Tear stop position 60 Virtual tear straight line 100 Cut 110 Farthest part 115 Farthest part tangent 140 Convex shape 150 End part 160 Straight line part 170 Convex arc radius

Claims (8)

A packaging bag that is opened by tearing
The tearing start point portion that is the starting point for starting the tearing, and the tearing stop position defined as the position where the tearing should be stopped.
With
The tear stop position has a notch and
The notch has a convex shape toward one side and the other side of the two parts of the packaging bag separated by a virtual tear straight line connecting the tear start point portion and the tear stop position, respectively.
Both vertices of the convex shape have an arc shape and
One of the convex ends of both is connected at the tear stop position.
And the other of both convex ends is not connected
The notch has the farthest portion farthest from the tear origin portion in the direction along the virtual tear straight line.
The slope of the tangent to the farthest part is perpendicular to the virtual tear straight line.
At least one of the convex shape, Ri opposite near the tearing said tear starting point portion of the stop position as a reference, and
The convex end on the opposite side of the tear start point with respect to the tear stop position, which is not connected at the tear stop position, is inserted inside the convex shape.
Packaging bag. Both the convex lies on the opposite side of the tearing said tear starting point portion of the stop position as a reference, packaging bag of claim 1. The packaging bag according to claim 1 or 2 , wherein the notch is symmetrical with respect to the virtual tear line. One of the convex shape, on the opposite side of the tearing said tear starting point portion of the stop position as a reference, and the other of said convex in said tear starting point portion side relative to the said tear stop position claim 1 The packaging bag described in. The packaging bag according to any one of claims 1 to 4 , wherein the portion where one of the respective ends of the convex shape is connected to each other is a straight line perpendicular to the virtual tear straight line. Of the notches, the end portion in the direction extending from the most distant portion of the convex shape to the side opposite to the tear stop position is the farthest portion and the tear stop position in the direction along the virtual tear straight line. The packaging bag according to any one of claims 1 to 5, which is located between. The packaging bag according to any one of claims 1 to 6 , wherein the apex of the convex shape has a shape having a substantially semicircle having a radius of 1.0 mm or more. The packaging bag according to any one of claims 1 to 7 , wherein the contents are enclosed inside and the contents can be taken out by opening the package by tearing.

Images