JP7137172B2 - Packaging bag manufacturing method - Google Patents

Description

The present invention includes, for example, raw materials for chemical products such as polyethylene grains, chemical raw materials such as food additives, civil engineering and gardening products such as fertilizers, culture soil, and gravel, foods such as salt, sugar, and polished rice, and pharmaceuticals. The present invention relates to the improvement of packaging bags used for storage and transportation of various products and the method of manufacturing the same, and in particular to the improvement of the efficiency of manufacturing and the improvement of handleability such as easy opening. .

For example, comparison of a width of about 600 mm and a height of about 800 mm to 1000 mm, which is used for packaging and transportation in large quantities when shipping chemical raw materials, civil engineering and gardening products such as fertilizers, foodstuffs, pharmaceuticals, etc. from factories etc. A large plastic packaging bag is manufactured by processing a plastic film obtained by inflation molding or lamination into a cylindrical shape and sealing the upper end (top) and the lower end (bottom).

In this case, by using a cyclic olefin resin such as a cyclic olefin polymer (COP) or a cyclic olefin copolymer (COC) as the plastic film, a simple cutting property can be obtained. (see, for example, Patent Document 1). These cyclic olefin resin films are excellent in both the MD direction (Machine Direction: the flow direction of the resin) and the TD direction (Transverse Direction: the width direction of the resin). It has a straight cutting property and can be torn with a small force, so it is used in applications such as the manufacture of packaging bags that require easy opening.

However, in order to express the easy cutting property of this cyclic olefin-based resin, it is necessary to apply a cut end to the film, and it is difficult to cut from a cut end other than the cut end formed by this cut end processing. It is real. That is, in order to express the easy cutting property, it is necessary to have a cut end that acts as a starting point for applying a shearing force. Notch processing that provides notches (see, for example, Patent Document 2), half-cut processing that uses a laser marker to cut halfway in the thickness direction of the film (see, for example, Patent Document 3), etc. have been performed. .

However, as for the notching process, the plastic film is processed into bags so that when a cylindrical plastic film is cut into a predetermined length to form a bag, the notch is formed in the same position for each bag. It is necessary to adjust the notch so that it is formed at a fixed position, and it is also necessary to change the position of the notch relatively according to the height of the bag. There was a problem that processing required a lot of labor and time. In this case, regardless of the height of the packaging bag, which is the final product, a notch is formed at a fixed position, and the cylindrical plastic film is cut to the required length at the cutting stage to obtain various dimensions. Although it is conceivable to provide the notches at the same position in the packaging bag, the plastic film is wasted accordingly, which is not preferable in terms of cost and environment.

In addition, since the packaging bag as a finished product can only be opened from this notch portion, especially when the notch is attached to a less conspicuous location, the user is forced to find the position of the notch. At the same time, even if a surplus portion that is not in contact with the contents is generated as the content of the packaging bag is reduced due to use, it is necessary to fold, tie, or shrink the surplus portion. In some cases, the part of the container was a hindrance in the operation of taking out the contents.

On the other hand, in half-cut processing, in addition to the same problems as above, the use of a laser for this processing is costly, and adjustment work to cut at an appropriate depth is difficult. Since the appropriate depth of cut also changes according to the thickness of the film, there is a problem that it is more difficult to adjust the depth.

Furthermore, in the case where the bag body is formed by stacking a plurality of plastic films and sealing the ends, the front and back sides of the bag are cut when the rear end of the seal is cut. However, if the cylindrical plastic film is simply folded, and in particular, if the cut is performed without sealing the ends, Depending on the method of processing, there is a possibility that the position of the cut edge may be misaligned.

In addition, since the conventional cut end is formed on the center side of the top seal part or the bottom seal part of the packaging bag, that is, on the side where the contents are filled, when the particle size of the contents is small , there is a risk that the contents may leak out from this cut portion. In addition, since the contents come into contact with the outside air through this cut, there is a possibility that the contents may be altered or deteriorated due to oxidation, moisture absorption, or the like.

JP 2015-123642 A JP 2007-55234 A JP 2006-312495 A

In view of the above problems, the problem to be solved by the present invention is that the user can easily cut from any point while efficiently manufacturing with simple work, and the bag body has To provide a packaging bag capable of preventing contents from leaking or deteriorating while exhibiting easy cuttability, and to provide a method for manufacturing such a packaging bag.

( 1. Manufacturing method of packaging bag)
The present invention, as a first means for solving the above problems, is a method for manufacturing a packaging bag having a bag body made of raw material whose main raw material is olefin, wherein the raw material is processed into a cylindrical shape and then folded. After forming the bag body having the crease-shaped end, before winding the bag body, the crease-shaped end of the bag body is pressed with a processing roll having a blade while applying tension to the bag body. It is passed between soft rolls that can be received, and the end is processed to form a cut for opening the packaging bag from the side part consisting of the fold-like end of the bag body originally formed in a cylindrical shape. Provided is a method for manufacturing a packaging bag characterized by applying a coating to a part continuously or periodically.

As a second means for solving the above problems, the present invention is characterized in that, in the above first solution means, processing is performed to form a cut in the fold-like end of the bag body over the entire length of the end. To provide a method for manufacturing a packaging bag.

As a third means for solving the above problems, the present invention provides a plurality of cut edges periodically or continuously in either the first or second means for solving the above problems. A method of manufacturing a packaging bag is provided.

As a fourth means for solving the above problems, the present invention provides, in any one of the first to third solutions, wherein at least a part of the cut face is formed facing the outer edge of the bag body, Provided is a method of manufacturing a packaging bag characterized by providing cuts in the outer edge of the main body.

As a fifth means for solving the above problems, the present invention is characterized in that, in any one of the first to fourth solutions, the cut edge is formed in a hole-like, linear or concave shape. To provide a method for manufacturing a packaging bag.

( 2. Packaging bag)
In addition, the present invention also provides the following packaging bag manufactured by the above first to fifth solution means. That is, as a sixth means for solving the above-mentioned problems, there is provided a packaging bag having a bag body formed by folding a raw material made of a raw material whose main raw material is olefin and processed into a cylindrical shape. The end portion is continuously or cyclically processed to form a cut for opening the packaging bag from the side portion consisting of the fold-like end portion of the bag body formed in a shape. To provide a packaging bag for

In addition, as a seventh means for solving the above problems, the present invention provides the sixth means for solving the above problems, wherein the processing for forming a cut in the fold-like end of the bag body is the entire length of the fold-like end. To provide a packaging bag characterized by being applied over the entire surface.

As an eighth means for solving the above problems, the present invention provides the sixth or seventh solution, wherein a plurality of cut edges are periodically or continuously formed at the fold-like end. To provide a packaging bag characterized by being formed.

As a ninth means for solving the above problems, the present invention provides a bag according to any one of the sixth to eighth solutions, wherein at least a part of the cut face is formed facing the outer edge of the bag body, To provide a packaging bag characterized by having cuts on the outer edge of the bag body.

As a tenth means for solving the above problems, the present invention is characterized in that in any one of the sixth to ninth solution means, the incision has a hole-like, linear or concave shape. To provide a packaging bag for

As an eleventh means for solving the above problems, the present invention provides, in any one of the sixth to tenth means for solving the above problems, the end of the bag body having a seal portion formed along the end. The present invention provides a packaging bag characterized in that the cut is formed in the sealing portion.

As a twelfth means for solving the above problems, the present invention provides any one of the sixth to eleventh solutions, wherein the olefin as the main raw material is a cyclic olefin such as a cyclic olefin polymer or a cyclic olefin copolymer. The present invention provides a bag for packaging a bag, which is characterized by being a poly-based resin.

As a thirteenth means for solving the above problems, the present invention provides any one of the sixth to twelfth means, wherein the bag body has a top seal portion or a bottom seal portion, and the top seal is A packaging bag, characterized in that a notch is formed starting from the upper end side or the lower end side of the top seal portion or the bottom seal portion and not extending toward the center of the bag body beyond the top seal portion or the bottom seal portion. It provides

As a fourteenth means for solving the above problems, the present invention provides the thirteenth solution, wherein the notches are arranged in parallel with the fold-shaped end of the bag body or with respect to the fold-shaped end of the bag body. To provide a packaging bag characterized by being formed obliquely at an angle.

As a fifteenth means for solving the above problems, the present invention provides any one of the sixth to fourteenth solutions, wherein the bag body has a top seal portion or a bottom seal portion, and the top seal is To provide a packaging bag characterized by having a notch formed on the central side of a part or a bottom seal part, and sealing the periphery of the notch.

According to the present invention, as described above, the fold-shaped end of the bag body is continuously or cyclically processed to form cuts for unsealing across the bag body from the end. Therefore, when a continuous cylindrical plastic film is cut into a predetermined length to form a bag, there is no need to adjust the position of the cut end, and processing of the cut end is laborious, time-consuming, and wasteful of resources. There is a practical benefit of being able to process efficiently without requiring

In this case, according to the present invention, as described above, the processing for forming the cut ends at the fold-shaped ends of the bag body is performed over the entire length of the fold-shaped ends. It can be opened from any point on the end of the bag (side of the bag body), eliminating the need for the user to find a cut, and the contents can be opened upward as the contents of the packaging bag decrease due to use. If there is a surplus part that is not in contact with the There is a practical benefit in that the removal work can be performed smoothly without hindering the work. In this case, "processing is performed over the entire length" means that processing is performed over the entire length, and the cut edge itself does not need to exist continuously over the entire length.

According to the present invention, as described above, a plurality of cut edges are periodically or continuously formed in the fold-like end portion, so that cut edge processing is performed continuously or periodically. Therefore, there is a practical advantage that the user can easily open the bag from an arbitrary position on the fold-shaped end of the bag body (the side of the bag body).

According to the present invention, as described above, as a result of continuous or periodic cut processing, at least some of the multiple cuts formed are, for example, linear cuts. A cut is provided in the outer edge of the bag body facing the outer edge of the body or, if a hole-shaped or concave cut is formed facing the outer edge of the bag body, so that the end of the bag body There is a practical advantage that the cut that triggers opening is always present, and the user can reliably apply a shearing force to the bag body from this cut, so that the bag body can be opened easily and reliably. . In this case, as described above, there is a practical advantage in that the cut ends can have an appropriate shape, such as a hole-like shape, a linear shape, or a concave shape, depending on the manufacturing situation.

According to the present invention, as described above, the end portion of the bag body has a seal portion formed along the end portion, and the cut portion is formed in this seal portion, so airtightness can be achieved as necessary. There is a practical benefit that can express easy cutability while maintaining

Furthermore, according to the present invention, as described above, the olefin that is the main raw material is a cyclic olefin-based resin such as a cyclic olefin polymer or a cyclic olefin copolymer. Therefore, there is a practical benefit that easy cutting can be expressed.

In addition, according to the present invention, as described above, when performing this cut end processing, the fold-like end of the bag body can be received by a processing roll having a blade and a blade while applying tension to the bag body. In particular, even when the bent end of the cylindrical plastic film is used as the bag body without sealing, the front and back plastic slips and the position is shifted. It is possible to prevent the cut end from being formed at a position other than the predetermined position, and to form the bag body by forming the raw material into a cylindrical shape and folding it in this way to form the cut end appropriately. Therefore, the bag body can be formed by omitting the steps of stacking and sealing the films, compared to the case where the bag body is formed by stacking a plurality of plastic films and then sealing the ends. , there is a practical benefit of being able to form the bag body efficiently.

Further, according to the present invention, as described above, in the bag body having the top seal portion or the bottom seal portion, starting from the upper end side or the lower end side of the top seal portion or the bottom seal portion, Since the notch is formed so as not to extend toward the center of the top or bottom seal portion, or the notch is formed toward the center of the top seal portion or bottom seal portion, the circumference of the notch is Since the bag is sealed, the notches provide an opportunity to open the bag and allow the easy cutting property of the bag body to be exhibited. Even if it is fine, it is possible to prevent the contents from leaking out to the outside, and at the same time, it is possible to prevent the contents from being changed or deteriorated due to oxidation or moisture absorption due to contact with the outside air. be.

1 is a schematic front view of a packaging bag of the present invention; FIG. FIG. 4 is an enlarged view of a cut end of the packaging bag of the present invention. FIG. 2 is a schematic side view of a state in which the packaging bag of the present invention is manufactured; FIG. 4 is a schematic front view of another embodiment of the packaging bag of the present invention; FIG. 4 is a schematic front view of still another embodiment of the packaging bag of the present invention;

Referring to the drawings, an embodiment of the present invention will be described in detail. FIG. 1 shows a packaging bag 10 of the present invention. Chemical raw materials such as additives, civil engineering and gardening products such as fertilizers, potting soil, and gravel, food products such as salt, sugar, and polished rice, and various products such as pharmaceuticals are packaged and transported in large quantities when shipped from factories, etc. It is a relatively large bag with a width of about 600 mm and a height of about 800 mm to 1000 mm, which is used for such purposes. As shown in FIG. 1, the packaging bag 10 has a bag body 12, and as shown in FIGS. 1 and 2, the bag body 12 is formed with a cut edge 14a at its fold-like end portion 12a. The processing 14 to do is given.

(1. Bag body)
The bag body 12 is made of a raw material whose main raw material is olefin, and as shown in FIG. It is manufactured by making a prototype of the bag body 12, cutting it to a required length, and then top-sealing or bottom-sealing the upper end and the lower end.

Cyclic olefin-based resins can be used as the olefin, which is the main raw material, and specific examples include cyclo-olefin polymer (COP) and cyclic olefin copolymer (COC). be able to. These cyclic olefin resins have excellent straightness in both the MD direction (Machine Direction: the flow direction of the resin) and the TD direction (Transverse Direction: the width direction of the resin). This is because the packaging bag 10 can be easily cut, and the cutting edge provides an opportunity for cutting (opening), so that the packaging bag 10 can be torn with a small force.

In this case, these cyclic olefin resins can be used alone to form a single-layer inflation tube film. It can also be the body 12 . Specifically, this polyethylene has a melt flow rate (hereinafter simply referred to as MFR) in accordance with JIS K7210 of 0.03 g/10 min to 4.0 g/10 min, and has a C (carbon number) of 4 to C8. linear low density polyethylene (LLDPE) having side chains of Such linear low-density polyethylene (LLDPE) is produced by adding an α-olefin having 4 to 8 carbon atoms such as butene-1, hexene-1, 4-methylpentene-1, and octene-1 during its production. can do. Using this linear low density polyethylene (LLDPE), for example, the intermediate layer has a layer in which a cyclic olefin resin and linear low density polyethylene (LLDPE) are blended, and the outermost layer and innermost layer on both sides In addition, the multi-layered bag body 12 may further include linear low-density polyethylene (LLDPE).

When used in combination with polyethylene such as linear low density polyethylene (LLDPE), it is desirable to use cyclic olefin copolymer (COC) among cyclic olefin resins. This is because the cyclic olefin copolymer (COC) has better compatibility with polyethylene and higher workability than the cyclic olefin polymer (COP). On the other hand, use of a cyclic olefin copolymer (COC) also increases costs, so a relatively flexible cyclic olefin polymer (COP) can be used alone as needed, such as for the use of the packaging bag 10.

In order to improve the properties of the packaging bag 10, the raw material of the bag body 12 may be added with additives such as a weather resistance agent, a flame retardant, an antioxidant, an antistatic agent, and a slipping agent, if necessary. It can be added within a range that does not affect the properties of the bag 10 .

As shown in FIG. 3, the raw material prepared as described above is fed from the hopper of the inflation molding machine 1 into a heated cylinder, kneaded in a completely molten state, and fed by a screw into an annular die. After being extruded into a cylindrical shape from the lip part while blowing air, it is cooled by an air ring, pulled up by a pinch roll 2, and the original shape of the bag body 12 The polyethylene in a state where the cylinder is crushed It is continuously formed into a raw fabric (cylindrical film). The blow ratio, which is the degree of expansion due to air blowing at this time, is an important factor that affects the orientation balance of this cylindrical film, and by extension, the strength, transparency, and film formation stability. It is preferable to set it between 0.0 and 3.0.

In this case, the cylindrical film, which is the original shape of the bag body 12, is formed with a width of 400 mm to 600 mm adjusted according to the application and need. The bag body 12 is manufactured by cutting the cylindrical film molded to a predetermined width into lengths of 800 mm to 1000 mm according to the application and needs, as shown in FIGS. .

In addition, in the present invention, the bag body 12 is formed with a thickness of 50 μm to 300 μm. In this case, the upper limit of 300 μm is set because if the thickness exceeds 300 μm, the packaging bag 10 lacks flexibility and adversely affects folding and packaging operations. Therefore, by setting the thickness to 300 μm or less, it does not have excessive rigidity and can exhibit good handleability even when folded. On the other hand, however, it is necessary to appropriately adjust the settings of the inflation molding machine 1, including the blow ratio, in order to form a film having a thickness exceeding 150 μm. Further, when the packaging bag 10 of the present invention is used alone, the thickness is set to about 100 μm to 150 μm to ensure strength, while it is used as an inner bag of a kraft bag made of kraft paper, for example. In that case, the thickness can be 70 μm to 80 μm.

The method of forming the raw material into a cylindrical film, which is the original shape of the bag body 12, is not necessarily limited to the above-mentioned inflation molding. , In addition, for example, a film is first formed by a T-die molding method, a calendar molding method, or a stretching method, and then both ends of the film in the length direction or width direction are heat-sealed to form a lamination process. It can also be used as a shaped film.

In addition, at the ends 12a of the bag main body 12, seal portions are formed along the ends (continuously in a belt-like manner at both left and right ends of the bag main body 12) depending on the contents, especially when airtightness is required. A cut 14a, which will be described later, can be formed in this seal portion. On the other hand, when high airtightness is not required or when breathability is required, the cut 14a, which will be described later, can be formed without forming the seal portion. can also be formed.

(2. Cutting edge processing)
In the present invention, as shown in FIGS. 1 and 2, a cut 14a formed at the fold-like end 12a of the bag body 12 is a cut that traverses the bag body 12 from the end 12a for opening. is. That is, the cut end 14a in the present invention is not for opening from the upper end or the lower end of the cut surface of the bag body 12 cut to the required length toward the other end, but is originally formed in a cylindrical shape. A cut edge 14a for opening the packaging bag 10 from a side portion of the bag body 12 formed by the fold-shaped end portion 12a. Therefore, the cut 14a is a portion of the bag body 12 that is originally cylindrical and continuous, and serves as the cut 14a for opening from a location where it would be difficult to open if the processing 14 is not performed. .

In the present invention, as shown in FIGS. 1 to 3, the processing 14 for forming the cut edge 14a is performed continuously or periodically on the fold-like end portion 12a. Here, "continuously" means, as shown in FIG. 1, that the processing 14 itself is continuously applied, and the cut edge 14a itself need not be continuous. In addition, "periodically" means that there may be a small portion that is not processed, and basically, the portion that is processed 14 is more It is desirable that the portion processed 14 occupy substantially the entire area of the fold-like end portion 12a. As a result, when a continuous cylindrical plastic film is cut into a predetermined length to form a bag, the cut ends 14a are formed at the same locations between a plurality of packaging bags 10 as the same product. Since there is no need to adjust the position of the cut edge 14a, the cut edge processing 14 can be efficiently processed without requiring labor, time, and wasted resources.

Therefore, it is more desirable that the processing 14 for forming the cuts 14 in the fold-like end portion 12a of the bag body 12 is performed over the entire length of the fold-like end portion 12 as shown in FIG. As a result, the fold-shaped end portion 12a of the bag body 12 (the side portion of the bag body 12) can be opened from any point, eliminating the need for the user to search for the cut end 14a, and the packaging bag 10 can be opened. If a surplus part that is not in contact with the contents occurs due to the decrease due to the use of the contents, cut the surplus part to the required height without folding, tying, or squeezing the surplus part. Therefore, the surplus portion does not interfere with the work of taking out the contents, and the work of taking out the contents can be performed smoothly. In this case, "processing is performed over the entire length" means that the processing 14 is performed over the entire length, and the cut edge 14a itself need not necessarily exist continuously over the entire length. do not have.

(2-1. Cut)
For example, as shown in FIG. 2(A), the cut edge 14a may be formed in a plurality of linear arc-like shapes in multiple rows and multiple stages at the fold-like end portion 12a. When the cut edge 14a is such a mere cut, there is no particular limitation on the shape of the cut edge 14a.

Moreover, as shown in FIG. 2(B), for example, the incisions 14a may have a hole-like shape in which a plurality of circular holes are formed in multiple rows and multiple stages at the fold-like end portion 12a. In this case, the shape of the hole is not particularly limited, and any shape other than the illustrated circular shape, such as a triangle, a square, an ellipse, and a rhombus, can be used.

Furthermore, as shown in FIGS. 2(C) and 2(D), the incision 14a has a horizontal "V"-shaped concave shape (that is, a < shape) formed so as to face the fold-shaped end 12a. or > shape). In this case, "concave" means a notch formed toward the inside of the bag body 12 when viewed from the fold-shaped end 12a, and as shown in FIG. The cutouts can be arranged at predetermined intervals, or as shown in FIG. 2D, a plurality of cutouts can be continuously formed without intervals. However, the latter case can be applied only when the above-described seal portion is formed on the fold-shaped end portion 12a. The shape of this concave shape is also not particularly limited, and it can be any shape such as a U shape in addition to the illustrated V shape.

In this case, as shown in FIGS. 2A to 2C, a plurality of cuts 14a can be formed periodically. As shown in (D), a plurality of incisions 14a can be arranged continuously. Therefore, the user can easily open the bag from an arbitrary position on the fold-shaped end portion 12a of the bag body 12 (the side portion of the bag body 12).

However, in the incision 14a of any of these forms, in the case of the linear or perforated incision 14a, as shown in FIGS. 14a faces the outer edge of the bag body 12, and the concave cut 14a faces the outer edge of the bag body 12 as shown in FIGS. However, it is necessary that the outer edge of the bag body 12 is provided with a cut. This is because, as described above, even when a cyclic olefin polymer (COP) or a cyclic olefin copolymer (COC) is used, a break that serves as a trigger for opening is necessary in order to develop its easy cuttability. . As a result, as shown particularly in FIG. 2, the end 12a of the bag body 12 always has a cut that serves as a trigger for opening, and the user reliably applies a shearing force to the bag body 12 through this cut. The bag body 12 can be opened easily and reliably.

(2-2. Processing method)
As shown in FIG. 3, such an incision 14a passes the fold-shaped end 12a of the bag body 12 between the processing roll 3 having the blade 3a and the soft roll 4 capable of receiving the blade 3a. can be formed by The shape, position and number of the cut edges 14a and the width of the processing 14 are determined by the shape, position, number and width of the blades 3a of the processing roll 3. FIG.

In this case, when performing the cut end processing 14, as shown in FIG. 3, it is desirable to pass the bag main body 12 between the processing roll 3 and the soft roll 4 while applying tension. As a result, even when the bag body 12 is formed without sealing the bent ends 12a of the cylindrical plastic film, the plastic on the front and back sides slides on each other, resulting in misalignment and misalignment. It is possible to prevent the cut end 14a from being formed, and to form the bag main body 12 by forming the raw material into a cylindrical shape and folding it to form the bag main body 12. Compared to the case of forming the bag body 12 by overlapping the plastic films and sealing the ends, the bag body 12 can be formed by omitting the process of overlapping and sealing the films, which is efficient. , the bag body 12 can be formed.

As shown in FIG. 3, the step of applying the cut end processing 14 can also be performed by passing the bag body 12 between the processing roll 3 and the soft roll 4 as it is after forming the bag body 12 and before winding it up. can. In this case, processing rolls 3 and soft rolls 4 can be used instead of the pinch rolls 2 unlike the illustrated embodiment. Also, after the bag body 12 has been once wound up, the cutting edge processing 14 can be performed when sending it to another process. In the illustrated embodiment, as shown in FIG. 33, both fold-shaped ends 12a are processed 14, but it is also within the scope of the present invention to process only one of the ends 12a. include.

(3. Notch)
Moreover, in the present invention, apart from the above-described cut edge processing 14, as a means for assisting opening, a notch 16 can be formed as shown in FIGS. Specifically, first, as shown in FIG. 4, the notch 16 starts from the upper end side of the top seal portion 18 applied to the upper end of the bag body 12 and does not extend to the center side of the top seal portion 18. can be formed. In this embodiment, the notch 16 is formed only to the upper end side of the top seal portion 18, or to a position where it stays within the top seal portion 18, and is further than the top seal portion 18 in which the contents are stored. It never reaches the center.

For this reason, the notches 16 provide an opportunity to open the bag and allow the easy cutting property of the bag body 12 to be exhibited, and the contents do not reach the notches 16, so that the particle size of the contents is reduced. Even if the contents are fine, the contents can be prevented from leaking out to the outside, and at the same time, the contents can be prevented from being altered or deteriorated due to oxidation, moisture absorption, etc. due to contact with the outside air.

In addition, in the embodiment shown in FIG. 4, the notch 16 is formed so as to be inclined with respect to the fold-like end portion 12a of the bag body 12. As shown in FIG. This is because the slanted shape is suitable for smooth opening in the transverse direction of the bag body, as shown in FIG. Therefore, as shown in FIG. 4, the notch 16 is preferably formed near one end of the upper end of the bag body 12 and inclined toward the other end. However, the notch 16 is not limited to this inclined notch 16, and the notch 16 can be formed parallel to the fold-like end portion 12a of the bag body 12 as well. Similarly, in FIG. 4, the notch 16 is formed on the top seal portion 18 side, but the notch 16 is formed on the bottom seal portion side (not shown), starting from the lower end side of the bottom seal portion, and extending from the bottom seal portion. The notch 16 can also be formed so that it does not extend toward the center, or the notch 16 can be formed in both the top seal portion 18 and the bottom seal portion.

Furthermore, as another form of this notch 16, as shown in FIG. It is also possible to use a packaging bag 10 that is closed. In this case as well, the notch 16 is present on the side of the contents, and the periphery thereof is sealed by the enclosing seal 20. Therefore, as in the embodiment shown in FIG. can be done.

The notches 16 in this FIG. 5 embodiment can be formed at the same time as the surround seal 20 . Specifically, for example, a mold (not shown) having a shape such as a semicircular shape with a projection in the center is pressed against the vicinity of the top seal portion 18 of the bag body 12 to form the enclosing seal 20, and at the same time the projection of the mold is formed. A notch 16 can be cut in by . Of course, the formation method is not limited, and the notch 16 may be formed in the enclosing seal 20 after the enclosing seal 20 is formed. In the embodiment of FIG. 5, the enclosing seal 20 is also formed in a substantially semicircular shape, but the shape is not particularly limited as long as it can prevent the outflow and deterioration of the contents. It can also be shaped.

The present invention includes, for example, raw materials for chemical products such as polyethylene grains, chemical raw materials such as food additives, civil engineering and gardening products such as fertilizers, culture soil, and gravel, foods such as salt, sugar, and polished rice, and pharmaceuticals. It can be widely applied to storage and transportation of various products.

REFERENCE SIGNS LIST 1 inflation molding machine 2 pinch roll 3 processing roll 3a blade 4 soft roll 10 packaging bag 12 bag body 12a crease-shaped end 14 processing to form cut 14a cut 16 notch 18 top seal portion 20 enclosure seal

Claims (5)

A method for manufacturing a packaging bag having a bag body made of a raw material whose main raw material is olefin, wherein the raw material is processed into a cylindrical shape and then folded to form the bag body having a fold-like end , Before winding the bag body, the fold-shaped end of the bag body is passed between a processing roll having a blade and a soft roll capable of receiving the blade while applying tension to the bag body. 2) continuously or periodically performing a process of forming a cut for opening the packaging bag from a side portion consisting of the fold-like end of the bag body which is initially formed in a cylindrical shape; A method for manufacturing a packaging bag, characterized by: 2. The method of manufacturing a packaging bag according to claim 1 , wherein the fold-shaped end of the bag body is processed to form a cut over the entire length of the end. Method. 3. The method of manufacturing a packaging bag according to claim 1 or 2 , characterized in that a plurality of said cut edges are periodically or continuously formed at said crease-shaped ends. A method for manufacturing a packaging bag that 4. The method of manufacturing a packaging bag according to any one of claims 1 to 3 , wherein at least a part of the cut edge is formed facing the outer edge of the bag body, and the outer edge of the bag body is cut. A method for manufacturing a packaging bag, comprising: 5. The method of manufacturing a packaging bag according to any one of claims 1 to 4 , wherein the cut edge is formed in a hole-like, linear or concave shape. Method.

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