JP2020132172A - Packaging bag and tear guidance weakening line forming method for packaging bag - Google Patents

Abstract

To provide a packaging bag enabling a tear from a tear starting part to pass through an auxiliary guidance line and surely reach a main guidance line connected thereto.SOLUTION: This packaging bag in which tear guidance weakening lines 10, 20 for guiding a tear from a first tear starting part 15a are respectively formed in first and second films 100a, 100b is configured such that the tear guidance weakening lines 10, 20 include main guidance lines 11, 21 extending in a direction away from a first junction 16, and first auxiliary guidance lines 12a, 22a extending in a direction away from the outer edge line of the first junction 16, connected to the main guidance lines 11, 21, and then returned toward the outer edge line, and the first auxiliary guidance lines 12a, 22a have a part 123 within a predetermined range including connection points P with the main guidance lines 11, 21 as a fist specially shaped part which is a linear groove deeper and/or thicker than the main guidance lines 11, 21.SELECTED DRAWING: Figure 1

Description

The present invention relates to a packaging bag having easy-to-open properties and a method for forming a tear-inducing weakening line in the packaging bag.

Conventionally, a packaging bag having the ease of opening described in Patent Document 1 is known. This packaging bag is formed in a bag shape by superimposing two resin films (first film and second film) on the front and back surfaces and heat-sealing the peripheral edge portion. Then, notches (tear start portions) are formed on the left and right side edges, and cut lines (tear induction weakening lines) for linearly weakening the resin film to induce tear from the notches are on the front and back 2 It is formed on each of the sheets of resin film. The cut line extends from the outer edge line of the side edge portion where the notch is formed, returns to the outer edge line of the side edge portion, and has a "dogleg" shape (V shape) formed so as to surround the notch. It includes an opening guide line (auxiliary guide line) and a planned opening guide line (main guide line) formed so as to extend linearly from the apex of the dogleg of the opening guide line to the side edge on the opposite side.

In such a packaging bag, when the tear from the notch reaches the opening guide line (auxiliary guide line) formed so as to surround the notch, the tear proceeds while being guided by the opening guide line, and the planned opening line (main). It will reach the guide line). Then, the tear that reaches the planned opening line advances to the opposite side edge while being guided by the planned opening line (main guide line), so that the packaging bag is opened.

According to such a packaging bag, the tear from the notch on one side edge is guided to the opening guide line and the planned opening line, which are the cut lines, and proceeds to the opposite side edge, so that the bag can be easily opened (easy to open). Can be opened).

Japanese Unexamined Patent Publication No. 2015-189483

In the packaging bag as described above, the tear from the notch on one side edge is connected to the planned opening line (main guide line) via the opening guide line (auxiliary guide line) formed so as to surround the notch. It is important to make sure that you proceed.

The present invention has been made in view of such circumstances, and provides a packaging bag capable of surely allowing tearing from a tear starting portion to proceed to a main guide wire connected to the auxiliary guide wire via an auxiliary guide wire. ..

Further, the present invention provides a method for forming a tear induction weakening line including the auxiliary guide wire and the main guide wire so that the tear from the tear start portion surely proceeds to the main guide wire connected to the auxiliary guide wire. It is to provide.

The packaging bag according to the present invention is formed by joining the peripheral portions of the first film and the second film to form a bag shape, and joining the peripheral portions of the first film and the second film. A packaging bag in which a first tear start portion is formed at the first joint portion, and a tear induction weakening line for inducing tear from the first tear start portion is formed on each of the first film and the second film. The tear-inducing weakening line extends in a direction away from the first joint portion side and in a direction away from the outer edge line side of the first joint portion, and is connected to the main guide line to form the outer edge line. The first auxiliary guide line includes a first auxiliary guide line that returns toward the side, and the first auxiliary guide line is a line that is deeper or thicker than the main guide line in a predetermined range including a connection point with the main guide line. It has a structure as a first special shape portion which is a shaped groove.

According to such a configuration, when the tear from the first tear start portion reaches the first auxiliary guide line, the tear is guided by the first auxiliary guide line and includes a predetermined connection point with the main guide line. At the part of the range, it advances through the first special shape part which is a linear groove deeper and / or thicker than the main guide line. Then, the tearing proceeds from the first special shape portion, which can be a portion more easily torn than the main guide line due to the shape of the linear groove, to the main guide line via the connection point with the main guide line.

In the packaging bag according to the present invention, the portion of the predetermined range including the connection point of the first auxiliary guide wire with the main guide wire is a curved wire portion that becomes convex in a direction away from the first joint portion side. It can be configured to include.

According to such a configuration, the tear from the first tear induction start portion that has reached the first auxiliary guide line proceeds through the first auxiliary guide line, and as a first special shape portion that can be a portion that is easier to tear than the main guide line. From the curved line portion of the above, the main guide line proceeds through the connection point with the main guide line.

In the packaging bag according to the present invention, the first auxiliary guide wire extends from the outer edge line of the first joint portion, connects with the main guide wire, returns to the outer edge line, and surrounds the first tear start portion. Can be configured to have.

According to such a configuration, since the first auxiliary guide wire extends from the outer edge line of the first joint portion and returns to the outer edge line to surround the first tear start portion, the tear from the first tear start portion is caused. It will reach the first auxiliary guide line more reliably. As a result, the tear proceeds through the first auxiliary guide line, and proceeds from the first specially shaped portion, which can be a portion that is easier to tear than the main guide line, to the main guide line via the connection point with the main guide line.

In the packaging bag according to the present invention, a second tear start portion is formed at the second joint portion facing the first joint portion, and the tear induction weakening line is further formed from the outer edge line side of the second joint portion. A second auxiliary guide line extending in a direction away from the main guide line, connecting to the main guide line and returning toward the outer edge line is included, and the second auxiliary guide line is in a predetermined range including a connection point with the main guide line. The portion may be configured to have a portion as a second specially shaped portion that is a linear groove deeper or thicker than the main guide wire.

According to such a configuration, when the tear from the second tear start portion reaches the second auxiliary guide line, the tear is guided by the second auxiliary guide line and includes a predetermined connection point with the main guide line. At the portion of the range, proceed through the second specially shaped portion, which is a linear groove deeper and / or thicker than the main guide line. Then, the tearing proceeds from the second special shape portion, which can be a portion more easily torn than the main guide wire due to the shape of the linear groove, to the main guide wire via the connection point with the main guide wire.

In the packaging bag according to the present invention, the portion of the predetermined range including the connection point of the second auxiliary guide wire with the main guide wire includes a curved line portion that becomes convex in a direction away from the second joint portion. It can be configured.

According to such a configuration, the tear from the second tear start portion that has reached the second auxiliary guide line proceeds through the second auxiliary guide line, and as a second special shape portion that can be a portion that is easier to tear than the main guide line. Proceed from the curved line portion to the main guide line via the connection point with the main guide line.

In the packaging bag according to the present invention, the second auxiliary guide wire extends from the outer edge line of the second joint portion, connects with the main guide wire, returns to the outer edge line, and surrounds the second tear start portion. Can be configured to have.

According to such a configuration, since the second auxiliary guide wire extends from the outer edge line of the second joint portion and returns to the outer edge line to surround the second tear start portion, the tear from the second tear start portion is caused. It will reach the second auxiliary guide line more reliably. As a result, the tear proceeds through the second auxiliary guide line, and proceeds from the second specially shaped portion, which can be a portion that is easier to tear than the main guide line, to the main guide line via the connection point with the main guide line.

Further, in the method for forming a tear-inducing weakening line according to the present invention, the first film and the second film are formed into a bag shape by joining the peripheral portions thereof, and each of the first film and the second film is formed. A tear start portion is formed at the joint portion formed by joining the peripheral portions, and a tear induction weakening line for inducing tear from the tear start portion is a packaging bag formed on each of the first film and the second film. The tear-inducing weakening line extends in a direction away from the joint portion side and away from the outer edge line side of the joint portion, connects to the main guide wire, and faces the outer edge line side. A method for forming the tear-inducing weakening line in a packaging bag including an auxiliary guiding wire that returns, and processing the tear-inducing weakening line to be formed in each of the first film and the second film by laser irradiation. It has a first step of forming the auxiliary guide line and a second step of forming the main guide line, and the first step is the auxiliary guide line. A configuration including a step of forming a portion of a predetermined range including a connection point with the main guide line by superimposing laser light more than the number of times of irradiation of the laser light at the time of forming the main guide line. It becomes.

According to such a configuration, in the first step of forming the auxiliary guide line, a portion of a predetermined range including the connection point of the auxiliary guide line with the main guide line is irradiated with a laser beam for forming the main guide line. Since it is formed by irradiating the laser beam more than the number of times of irradiation, the portion of the predetermined range including the connection point of the auxiliary guide line with the main guide line is at least a linear groove deeper than the main guide line. Can be.

Further, in the method for forming a tear-inducing weakening line according to the present invention, the first film and the second film are formed into a bag shape by joining the peripheral portions thereof, and each of the first film and the second film is formed. A tear start portion is formed at the joint portion formed by joining the peripheral portions, and a tear induction weakening line for inducing tear from the tear start portion is a packaging bag formed on each of the first film and the second film. The tear-inducing weakening line extends in a direction away from the joint portion side and away from the outer edge line side of the joint portion, connects to the main guide wire, and faces the outer edge line side. A method for forming the tear-inducing weakening line in a packaging bag including the auxiliary guiding wire and the tear-inducing weakening line to be formed on each of the first film and the second film by laser processing. It is a step of forming as a groove, and has a first step of forming the auxiliary guide line and a second step of forming the main guide line, and the first step is the step of forming the auxiliary guide line. The configuration includes a step of irradiating a predetermined range of a portion including a connection point with the main guide wire a plurality of times while shifting the portion at a pitch equal to or less than the spot diameter of the laser beam.

According to such a configuration, in the first step of forming the auxiliary guide wire, a portion of a predetermined range including the connection point of the auxiliary guide wire with the main guide wire is shifted at a pitch equal to or less than the spot diameter of the laser beam. However, since it is formed by irradiating the laser beam a plurality of times, a portion of a predetermined range including the connection point of the auxiliary guide line with the main guide line can be a linear groove at least thicker than the main guide line.

Furthermore, in the method for forming a tear-inducing weakening line according to the present invention, the first film and the second film are formed into a bag shape by joining the peripheral portions thereof, and the first film and the second film are formed. A packaging bag in which a tear start portion is formed at a joint portion formed by joining the peripheral portions thereof, and a tear induction weakening line for inducing tear from the tear start portion is formed on each of the first film and the second film. The tear-inducing weakening line extends in a direction away from the joint portion side and in a direction away from the outer edge line side of the joint portion, and is connected to the main guide line to the outer edge line side. A method for forming the tear-inducing weakening line in a packaging bag including an auxiliary guiding wire returning toward the first film and the tear-inducing weakening line to be formed in each of the first film and the second film by laser processing. It has a first step of forming the auxiliary guide line and a second step of forming the main guide line, and the first step is the auxiliary guide line. Of the laser beam, the portion of the predetermined range including the connection point with the main guide line is irradiated with the portion of the predetermined range including the connection point of the auxiliary guide line with the main guide line when the main guide line is formed. The configuration includes a step of forming by irradiating a laser beam having an output larger than the output.

According to such a configuration, in the first step of forming the auxiliary guide line, a laser that irradiates a predetermined range portion including the connection point of the auxiliary guide line with the main guide line when forming the main guide line. Since it is formed by irradiating a laser beam with an output larger than the output of the light, the portion of the predetermined range including the connection point of the auxiliary guide line with the main guide line is a linear shape deeper or thicker than the main guide line. It can be a groove.

In each of the tear guide weakening line forming methods described above, either step 1 of forming the auxiliary guide line or step 2 of forming the main guide line may be executed first.

According to the packaging bag according to the present invention, the tear from the first tear start portion proceeds through the first auxiliary guide wire, and the connection point from the first special shape portion to the main guide wire, which can be a portion that is easier to tear than the main guide wire. Since it proceeds to the main guide line via the above, the tear from the first tear start portion can surely proceed to the main guide line via the first auxiliary guide line.

Further, according to the method for forming each tear-inducing weakening wire according to the present invention, a portion of the auxiliary guiding wire including the connection point with the main guiding wire is formed from the main guiding wire by processing the laser beam irradiation. Since it can be a deep and / or thick linear groove, a portion of a predetermined range including a connection point of the auxiliary guide wire with the main guide wire can be a portion that is more easily torn than the main guide wire. Therefore, it is possible to form a tear induction weakening line in which the tear from the tear start portion can surely proceed to the main guide line via the auxiliary guide line.

FIG. 1 is a front view showing a main part of a packaging bag according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an example of each layer structure of the front side film and the back side film constituting the packaging bag shown in FIG. 1 and an example of a groove formed by laser processing as a tear induction weakening line. FIG. 3 shows an enlarged view of the left notch (first tear start portion) formed in the packaging bag shown in FIG. 1 and the tear guide weakening line (first auxiliary guide line, main guide line) formed in the vicinity thereof. It is a figure. FIG. 4 is a further enlarged view of the region A in FIG. FIG. 5 is a cross-sectional view showing an example of a groove formed by laser processing of a curved line portion of the first auxiliary guide line. FIG. 6 is a diagram showing an example of how to tear the packaging bag shown in FIG. 1 when it is opened. FIG. 7 is a diagram showing an opening opening of a packaging bag that has been torn and opened by the tearing method shown in FIG. FIG. 8A is a diagram showing an example of a tear cut from the first auxiliary guide line to the main guide line. FIG. 8B is a diagram showing an example of a tear cut cut guided to the main guide line up to the outer edge line of the second joint. FIG. 9 is a diagram showing an example of a state in which the first tear-inducing weakening line and the second tear-inducing weakening line are deviated from each other. FIG. 10 is a diagram showing the result of the opening test.

Embodiments of the present invention will be described with reference to the drawings.

The packaging bag according to the embodiment of the present invention is configured as shown in FIG.

In FIG. 1, the packaging bag 100 is, for example, a pouch with a plastic zipper, and the front side film 100a (first film) and the back side film 100b (second film) are joined to each other to form a bag shape. Is formed in. As shown in FIG. 2, each of the front side film 100a and the back side film 100b has, for example, a PET layer 101 made of polyethylene terephthalate, a NY layer 102 made of nylon which is a polyamide synthetic resin, and an aluminum layer 103 made of aluminum foil. It has a structure in which four layers of PE layer 104 made of polyethylene and PE layer 104 are laminated. The PET layer 101 has high transparency, is hard to expand and contract, and has good dimensional stability, and is suitable as a layer for printing. The NY layer 102 is strong against impact and bending, has a property of being difficult to make holes, and is a layer for ensuring strength. The aluminum layer 103 is a metal layer for shielding the inflow and outflow of gas such as air (oxygen) and moisture with this layer as a boundary. The PE layer 104 has a property of melting at about 100 ° C. to 130 ° C., and is a layer as a sealant layer suitable for heat fusion.

In this way, the front side film 100a and the back side film 100b having a structure in which the PE layer 104 and the PET layer 101 are arranged on the outermost side of the front and back surfaces and the NY layer 102 and the aluminum layer 103 are laminated so as to be adjacent to each other are PEs. With the layers 104 facing each other, the PE layers 104 at the peripheral portions of the front side film 100a and the back side film 100b are sealed (bonded) by heat fusion to form a bag shape. As a result, with the PE layer 104 inside, as shown in FIG. 1, the seal portions (joint portions) 16, 17, and 18 (the lower seal portion facing the seal portion 18 is omitted) are sealed. The packaging bag 100 is formed.

Returning to FIG. 1, the packaging bag 100 has a plastic fastener extending linearly between two seal portions 16 and 17 facing each other in the lateral direction at a position separated from the upper seal portion 18 by a predetermined distance. 19 is provided. The plastic fastener 19 has a known structure and can be opened and closed. A storage portion for contents (for example, food and drink) is formed in a region opposite to the upper seal portion 18 with the plastic fastener 19 as a boundary. After opening, the contents can be taken out from the accommodating portion by opening the plastic fastener 19, and the accommodating portion containing the contents can be sealed by closing the plastic fastener 19.

When the packaging bag 100 is provided with a gusset portion at the bottom, the upper peripheral portions of the front side film 100a and the back side film 100b each accommodate the contents in the accommodating portion with the plastic fastener 19 open. After that, the plastic fastener 19 is closed and the housing portion is sealed in a sealed state, and the upper sealing portion 18 is formed. Further, in the case where the packaging bag 100 is a flat pouch having no gusset portion, after the upper sealing portions 18 of the front side film 100a and the back side film 100b are formed, the contents are accommodated from the lower peripheral portion. Then, the lower seal portion is formed.

Further, in FIG. 1, the first tear-inducing weakening line 10 is formed on the front side film 100a, and the second tear-inducing weakening line 20 is formed on the back side film 100b. A left notch 15a (first tear start portion) is formed in the seal portion 16 (first joint portion) on the left side of the packaging bag 100, and a right notch 15a (first tear start portion) is formed in the seal portion 17 (second joint portion) on the right side of the packaging bag 100. The 15b (second tear start portion) is formed so as to face the left notch 15a. Each of the first tear-inducing weakening line 10 and the second tear-inducing weakening line 20 extends from the outer edge line of the seal portion 16 to the outer edge line of the sealing portion 17 on the opposite side.

The first tear-inducing weakening line 10 formed on the front film 100a includes a main guiding wire 11 (10) extending from the outer edge line of the sealing portion 16 to the outer edge line of the sealing portion 17, a left notch 15a of the sealing portion 16, and a main guiding wire. The first auxiliary guide wire 12a (10) formed so as to surround the end portion of 11, and the second auxiliary guide wire 12b formed so as to surround the right notch 15b of the seal portion 17 and the end portion of the main guide wire 11. (10) is included. Further, the second tear induction weakening wire 20 formed on the back side film 100b is a main induction wire 21 (20) extending linearly from the outer edge edge of the seal portion 16 to the outer edge line of the seal portion 17, and the left notch of the seal portion 16. The first auxiliary guide wire 22a (20) formed so as to surround the ends of the 15a and the main guide wire 21, and the first auxiliary guide wire 22a (20) formed so as to surround the right notch 15b of the seal portion 17 and the end of the main guide wire 21. 2 Includes auxiliary guide wire 22b (20).

The left notch 15a and the right notch 15b are formed so as to overlap the ends of the main guide wire 11 and the main guide wire 21 on the front and back surfaces. However, due to variations in manufacturing conditions, the left notch 15a and the main guide wire 11 or The main guide line 21 or the right notch 15b and the main guide line 11 or the main guide line 21 may not exactly overlap.

The detailed shape of the first auxiliary guide wire 12a (10) formed on the front film 100a as a part of the first tear guide weakening line 10 is shown in FIG. In FIG. 3, the first auxiliary guide wire 12a has a straight line portion 121 having a predetermined length extending from the outer edge line of the front side film 100a (seal portion 16) so as to be orthogonal to the outer edge line, and the first auxiliary guide line 12a is inclined downward from the straight line portion 121. A curved line portion 122 extending so as to extend, and a curved line extending from the inclined line portion 122 in a convex curved shape (for example, an arc shape) in the tearing direction (direction away from the seal portion 16) and connecting to the main guide line 11. The portion 123, the inclined line portion 124 extending downward from the curved line portion 123, and the outer edge line of the front side film 100a (seal portion 16) continuing from the inclined line portion 124 so as to be orthogonal to the outer edge line. It is composed of a straight line portion 125 having a predetermined length returning to.

The second auxiliary guide line 12b has the same shape as the first auxiliary guide line 12a described above, and has the same relative positional relationship with the main guide line 11. Further, each of the first auxiliary guide wire 22a and the second auxiliary guide wire 22b formed on the back side film 100b as a part of the second tear guide weakening wire 20 has the same shape as the first auxiliary guide wire 12a described above. The positional relationship with the main guide line 21 is also the same as the relative positional relationship between the first auxiliary guide line 12a and the main guide line 11 in the front side film 100a described above.

Returning to FIG. 1, the packaging bag 100 (front side film 100a, back side film 100b) has three regions, a first region E1, a second region E2, and a third region in the tearing direction (width direction) starting from the left notch 15a. When divided into E3 substantially equally, in the first region E1, the set of the straight portion 111 of the first auxiliary guide wire 12a and the main guide wire 11 in the front side film 100a, and the first auxiliary guide wire 22a and the main in the back side film 100b. The set of the straight line portions 211 of the guide wire 21 is the first overlapping portion having the same shape and overlapping with each other. In the second region E2, the main guide wire 11 of the front side film 100a smoothly continues from the straight line portion 111 without including a portion extending upward (toward the upper sealing portion 18 side) from the straight line portion 111, and the plastic fastener 19 A curved portion 112 curved so as to project sideways (below the packaging bag 100). The curved portion 112 of the main guide wire 11 in the front film 100a and the straight portion 212 of the main guide wire 21 in the back film 100b are separated portions that do not overlap each other. Further, in the third region E3, the set of the straight portion 113 and the second auxiliary guide wire 12b of the main guide wire 11 in the front film 100a and the straight portion 213 and the second auxiliary guide wire 22b of the main guide wire 21 in the back film 100b. Is a second overlapping portion that has the same shape and overlaps with each other.

In the first tear-inducing weakening line 10 and the second tear-inducing weakening line 20, the first overlapping portion (first auxiliary guiding wire 12a, first auxiliary guiding wire 22a, straight line portion 111, straight portion 211) corresponding to the first region E1. ) In the tearing direction (width length of the first region E1) and the second overlapping portion (second auxiliary guide wire 12b, second auxiliary guide wire 22b, straight line portion 113, straight line portion) corresponding to the third region E3. The sum (length of the entire overlapping portion) with the length in the tearing direction of 213) (the width length of the third region E3) is the tearing of the separated portion (curved portion 112, straight portion 212) corresponding to the second region E2. It is longer (approximately twice as long) than the length in the direction (width length of the second region E2). That is, in the first tear-inducing weakening line 10 and the second tear-inducing weakening line 20, the length of the overlapping portion (first overlapping portion and second overlapping portion) in the tearing direction is longer than the length of the separated portion in the tearing direction.

The first tear guide weakening line 10 (main guide line 11, first auxiliary guide line 12a, second auxiliary guide line 12b) and the second tear guidance weakening line 20 (main guide line 21, first auxiliary guide line 22a, described above, The second auxiliary guide wire 22b) is formed on the front side film 100a and the back side film 100b by laser light irradiation (laser processing) from a laser light source. Specifically, the front side film 100a and the back side film 100b (actually, they) are emitted from the laser light source in a pulsed or continuously manner according to the shapes of the first tear-inducing weakening line 10 and the second tear-inducing weakening line 20. Irradiates the corresponding area of the raw film to be cut out. For example, in the first step, the first auxiliary guide lines 12a and 22a are formed, in the second step, the main guide lines 11 and 21 are formed, and in the third step, the second auxiliary guide lines 12b and 22b are formed. To. As a result, as shown in FIG. 2, the first tear guide weakening line 10 (first auxiliary guide line 12a, main guide line 11, second auxiliary guide line 12b) and the second tear guidance weakening line 20 (first auxiliary guide). The wire 22a, the main guide wire 21, and the second auxiliary guide wire 22b) are formed as a linear groove 110 having a depth from the PET layer 101 to the NY layer 102 of the front side film 100a and the back side film 100b.

In the first step, as shown in an enlarged view in FIG. 4 together with FIG. 3, the bay as a predetermined range including the connection point P of the first auxiliary guide line 12a of the first tear guide weakening line 10 with the main guide line 11. The curved portion 123 is formed by irradiating the laser beam a plurality of times (for example, twice) including the irradiation of the laser beam described above. As a result, as shown in FIG. 5, the curved line portion 123 reaches the aluminum layer 103, and the other portions of the main guide line 11 and the first auxiliary guide line 12a (straight line portions 121, 125, inclined line portion 122, It is formed as a linear groove 110 at least deeper than each of 124). Further, the curved line portion 123 can be formed by irradiating the curved line portion 123 a plurality of times while shifting the laser beam at a pitch equal to or less than the spot diameter of the laser beam. In this case, the curved wire portion 123 may be formed as a linear groove 110 that is at least thicker than each of the main guide wire 11 and the other portions of the first auxiliary guide wire 12a. Further, the curved line portion 123 is larger than the output of the laser beam when forming each of the main guide line 11 and the other portions (straight line portions 121, 125 and inclined line portions 122, 124) of the first auxiliary guide line 12a. It can be formed by irradiating the output laser beam. In this case, the curved wire portion 123 may be formed as a linear groove 110 deeper and / or thicker than the main guide wire 11 and the other portions of the first auxiliary guide wire 12a, respectively. It should be noted that the curved line portion 123 is deeper than the other portions of the main guide line 11 and the first auxiliary guide line 12a by each of the above-mentioned irradiation of the laser beam a plurality of times and the irradiation of the laser beam while shifting. It can also be formed as a thick linear groove 110.

The curved line portion 123 formed as a deeper and / or thicker linear groove 110 of the main guide line 11 and the other parts of the first auxiliary guide line 12a (straight line portions 121, 125, inclined line portions 122, 124), respectively, The degree of weakening is greater than that of the main lead wire 11 and the other portion, and the degree of easiness of tearing is greater than that of the main lead wire 11 and the other portion. That is, the curved wire portion 123, which is a linear groove deeper and / or thicker than the main guide wire 11 and the other portion, is more easily torn and is distinguished from the main guide wire 11 and the other portion. It is included in the first tear induction weakening line 10 as the first special shape portion.

Regarding the second auxiliary guide wire 12b connected to the main guide wire 11 in the first tear guide weakening wire 10, the curved line portion 123 of the second auxiliary guide wire 12b is described above in the same manner as the first auxiliary guide wire 12a described above. Irradiation modes (multiple irradiations, staggered irradiations, etc.) different from those of the main guide line 11 and the second auxiliary guide line 12b (straight line portions 121, 125, inclined line portions 122, 124) of the laser beam as described above. It is formed as deeper and / or thicker linear grooves 110 by power-enhancing irradiation). Therefore, the curved line portion 123 of the second auxiliary guide wire 12b is also more easily torn than the main guide wire 11 and the other portion, respectively, and is distinguished from the main guide wire 11 and the other portion. 2 As a special shape portion, it is included in the first tear induction weakening line 10. The same applies to each of the first auxiliary guide wire 21a and the second auxiliary guide wire 21b connected to the main guide wire 21 of the second tear guide weakening wire 20 formed on the back side film 100b, and the same applies to the first auxiliary guide. The curved line portion 123 of the line 21a is the first specially shaped portion formed as a deeper and / or thicker linear groove 110, and the curved line portion 123 of the second auxiliary guide wire 21b is deeper and / or thicker. It is a second specially shaped portion formed as a linear groove 110.

The packaging bag 100 described above can basically be opened, for example, as shown in FIG.

In FIG. 6, when the packaging bag 100 (front side film 100a, back side film 100b) starts to be torn from the left notch 15a of the sealing portion 16 toward the sealing portion 17 on the opposite side, the front side film 100a in the first region E1 The tearing proceeds while being guided by the straight portion 111 of the main guide line 11. Even if the tear deviates from the straight line portion 111 (main guide line 11), when it reaches the first auxiliary guide line 12a, it advances along the first auxiliary guide line 12a to reach the straight portion 111 of the main guide line 11. After that, the process proceeds while being guided by the straight line portion 111. At this time, the tearing of the back side film 100b also proceeds while being guided by the straight line portion 211 of the main guide line 21, and even if the tear deviates from the straight line portion 211 (main guide line 21), the first auxiliary It returns to the straight line portion 211 via the guide line 22a, and proceeds while being guided by the straight line portion 211.

In the first region E1, in the front side film 100a and the back side film 100b, tearing from the left notch 15a is simultaneously performed by the straight line portion 111 of the main guide line 11 and the straight portion 211 of the main guide line 21 (first overlapping portion). Proceed while being guided by. In this case, the packaging bag 100 is torn by overlapping the actual tear lines (see La and Lb in FIG. 6) between the front film 100a and the back film 100b without shifting. The details of the case where the tear from the left notch 15a deviates from the main guide lines 11 and 21 and proceeds while being guided by the first auxiliary guide lines 12a and 22a to reach the main guide line 11 will be described later.

When the tear of the packaging bag 100 moves from the first region E1 to the second region E2, the tear of the front film 100a moves from the straight portion 111 of the main guide line 11 to the curved portion 112, and proceeds while being guided by the curved portion 112. .. On the other hand, the tearing of the back side film 100b continues from the straight line portion 211 of the main guide line 21 to the straight line portion 212, and proceeds while being guided by the straight line portion 212. In this case, when the packaging bag 100 is torn, the front side film 100a and the back side film 100b are separated portions that do not overlap (curved portion 112 of the main guide wire 11 (10), straight portion 212 of the main guide wire 21 (20)). While being guided to, the actual tear line (see La and Lb in FIG. 6) is torn in a deviated state.

When the tear of the packaging bag 100 shifts from the second region E2 to the third region E3, the tear of the front side film 100a shifts from the curved portion 112 of the main guide wire 11 to the straight portion 113, and the tear of the straight portion 113 of the main guide wire 11 Proceed while being guided by. Then, the tear reaches the outer edge line of the seal portion 17 while being guided to the straight portion 113 of the main guide wire 11. On the other hand, the tearing of the back side film 100b also similarly moves from the straight line portion 212 of the main guide line 21 to the straight line portion 213, and proceeds while being guided by the straight line portion 213. Then, the tear reaches the outer edge line of the seal portion 17 while being guided to the straight portion 213. In this case, when tearing the packaging bag 100, the front side film 100a and the back side film 100b are simultaneously guided to the second overlapping portion (113, 213) and the actual tear line (see La and Lb in FIG. 6). The tears overlap and are torn without shifting, and the tears reach the outer edge of the seal portion 17 at once. In the third region E3, the tear guided by the main guide lines 11 and 21 passes through the connection point P (see FIG. 4) with the second auxiliary guide lines 12b and 22b. The tearing through P will be described later.

In this way, the packaging bag 100 is opened when the tear of the packaging bag 100 started from the left notch 15a of the sealing portion 16 reaches the outer edge line of the sealing portion 17 on the opposite side. When the packaging bag 100 is opened, as shown in FIG. 7, the edge line La of the opening cut end of the front side film 100a corresponds to the straight portion 111, the curved portion 112, and the straight portion 113 of the main guide wire 11. (The first auxiliary guide line 12a may be included). Further, the edge line Lb of the opening cut end of the back side film 100b corresponds to the straight portions 211, 212, 213 of the main guide line 21 (the first auxiliary guide line 22a may be included). Here, the curved portion 112 of the main guide wire 11 and the straight portion 212 of the main guide wire 21 corresponding to the second region E2 (see FIG. 6) of the first tear guide weakening line 10 and the second tear induction weakening line 20. Since is formed so as not to overlap as the separated portion, the portion of the edge line La of the opening cut opening of the front side film 100a corresponding to these separated portions (112, 212) and the edge line Lb of the opening cut opening of the back side film 100b. It is in a state of being deviated by the amount Δ without overlapping with the part of. Then, the back side film 100b of the displaced portion is picked and the opened packaging bag 100 is opened, and the plastic fastener 19 can be easily opened.

When the packaging bag 100 (front side film 100a, back side film 100b) is opened as described above, the tear from the left notch 15a deviates from the main lead wires 11 and 21 and guides them to the first auxiliary guide wires 12a and 22a. A case will be described in which the process proceeds while being carried out until the main guide line 11 is reached.

The tear that proceeds while being guided by the first auxiliary guide lines 12a and 22a (see FIG. 3) by the force applied in the extending direction of the main guide lines 11 and 21 proceeds from the inclined line portion 124 to the curved line portion 123, for example. .. The curved line portion 123 (first special shape portion) of the first auxiliary guide lines 12a and 22a is formed by a deep and / or thick linear groove 110 (even if the force is applied in the extending direction of the main guide lines 11 and 21. Since it is formed as (see FIG. 5), the tear proceeds more smoothly through the curved line portion 123. Then, the tear that proceeds smoothly while being guided by the curved line portion 123 is the connection point P with the main guide lines 11 and 21 due to the force applied in the extending direction of the main guide lines 11 and 21 (see FIG. 4). Then, it moves to the main guide lines 11 and 12 without proceeding through the curved line portion 123 as it is. After that, the tearing proceeds toward the sealing portion 17 on the opposite side while being guided by the main guide lines 11 and 21. As a result, the edge lines La and Lb of the opening cut ends of the front side film 100a and the back side film 100b continuing from the left notch 15a are, for example, as shown in FIG. 8A, the first auxiliary guide lines 12a and 22b (for example, the inclined line portion 124). , Curved line portion 123) and main guide lines 11 and 21.

As described above, the tear that advances while being guided by the main guide lines 11 and 21 enters the third region E3 (see FIG. 6) and enters the second auxiliary guide lines 12b and 22b (curved line portion 123 (see FIG. 4)). Reach the connection point P of. The curved line portions 123 of the second auxiliary guide wires 12b and 22b passing through the connection point P are convex in a direction away from the seal portion 17 (second joint portion) opposite to the tearing direction. Even if the curved line portion 123 (second special shape portion) of the second auxiliary guide wires 12b and 22b is formed as a deep and / or thick linear groove 110 (see FIG. 5), the curved line portion 123 (see FIG. 5) Coupled with the above-mentioned shape of the second special shape portion), the tearing is caused by the force applied in the extending direction of the main guide lines 11 and 21 from the main guide lines 11 and 21 via the connection point P. The outer edge line of the seal portion 17 is reached at once while being guided to the main guide lines 11 and 21 as it is without moving to 12b and 22b (curved line portion 123). As a result, on the opposite side of the left notch 15a of the tear start point, the edge lines La and Lb of the opening cut ends of the front side film 100a and the back side film 100b are, for example, as shown in FIG. 8B, the second auxiliary guide line 12b, Instead of 22b, it corresponds to the linear main guide lines 11 and 21.

It should be noted that, from the viewpoint of preventing the tear guided to the main guide lines 11 and 21 from diverting from the connection P to the second auxiliary guide lines 12a and 22b on the opposite side of the tear start point (notch 15a), the second The curved line portion 123 (second special shape portion) of the auxiliary guide wires 12b and 22b, which is a deeper and / or thicker linear groove 110, is preferably connected to the main guide wires 11 and 21 at right angles.

According to the above-mentioned packaging bag 100, the tear from the left notch 15a (first tear start portion) due to the force in the extending direction of the main guide lines 11 and 21 proceeds along the first auxiliary guide lines 12a and 22b, and is the main guide. From the curved line portion 123 (first special shape portion), which is more easily torn than the wires 11, 21 and other portions, to the main guide wires 11 and 21 via the connection point P with the main guide wires 11 and 21. Therefore, the tear from the left notch 15a (first tear start portion) can surely proceed to the main guide lines 11 and 21 via the first auxiliary guide lines 12a and 22a (see FIG. 8A).

Further, in the above-mentioned packaging bag 100, on the side opposite to the left notch 15a of the tear start point, the tear that proceeds while being guided by the main guide lines 11 and 21 is from the connection point P with the second auxiliary guide lines 12b and 22b. Without moving to the second auxiliary guide lines 12b and 22b, they are guided by the main guide lines 11 and 21 as they are and reach the outer edge line of the seal portion 17 at once. Therefore, the opening cut at the tear end can be in a straight and clean state without being disturbed (see FIG. 8B).

In the case of tearing starting from the right notch 15b on the opposite side of the left notch 15a described above, when the second auxiliary guide lines 12b and 22b are reached, the second auxiliary guide lines 12b and 22b are similarly described above. While being guided to, the process moves to the main guide lines 11 and 21 via the connection point P with the main guide lines 11 and 21. Further, also on the side opposite to the right notch 15b, as described above, the tear that proceeds while being guided by the main guide lines 11 and 12 is the connection point with the first auxiliary guide lines 12a and 22b (curved line portion 123). While being guided directly from P to the main guide lines 11 and 21, the outer edge line of the seal portion 16 is reached at once. Therefore, also in this case, the tear from the right notch 15b (second tear start portion) can surely proceed to the main guide lines 11 and 21 via the second auxiliary guide lines 12a and 22a, and at the tear end portion. The opening cut can be straight and clean without any disturbance. In this way, the first auxiliary guide lines 12a and 22a and the second auxiliary guide lines 12b and 22b are provided, and a predetermined range portion (curved line portion 123) including the connection point P with the main guide lines 11 and 21 is provided. By making it easier to tear than the main guide lines 11 and 21, it is possible to open the package along the main guide lines 11 and 21 regardless of whether the user opens it from the left or right, and the opening cut at the tear end portion is It can be in a straight and clean state without being disturbed.

By the way, the first tear-inducing weakening line formed on the front side film 100a due to the film cutting deviation, the film bonding deviation, the transferred film itself deviation, etc. that may occur in the manufacturing process of the packaging bag 100. The 10 and the second tear-inducing weakening line 20 formed on the back side film 100b may be slightly deviated from each other. Specifically, the straight portion 111 of the first auxiliary guide line 12a and the main guide line 11 of the front side film 100a and the first auxiliary guide line of the back side film 100b in the first region E1 (see FIG. 6) which should originally overlap. The 22a and the straight portion 211 of the main guide line 21 are slightly deviated from each other. Similarly, in the third region E3, the straight portion 113 of the second auxiliary guide wire 12b and the main guide wire 11 of the front side film 100a, and the straight portion of the second auxiliary guide wire 22b and the main guide wire 21 of the back side film 100b. There is a slight deviation from 213.

The curved line portions 123 of the first auxiliary guide lines 12a and 22a (second auxiliary guide lines 12b and 22b) are the main guide lines 11 and 21 and their first auxiliary guide lines 12a and 22a (second auxiliary guide lines 12b and 22b). ) Is effective against the deviation between the first tear-inducing weakening line 10 and the second tear-inducing line 10 as described above by forming the linear groove 110 deeper and / or thicker than each of the other parts. The following opening test was conducted to confirm whether or not it was present. Specifically, as shown in FIG. 9, the first tear guide weakening line 10 including the first auxiliary guide lines 12a and 22a having an interval of 6 mm on the outer edge line and the second tear guide line 20 overlap first. An opening test was conducted on the packaging bag 100 that was displaced by 4 mm in the portion (distance between the main guide wires 11 and 21 = 4 mm).

As described above, in the case of a packaging bag in which the curved wire portions 123 of the first auxiliary guide wires 12a and 22a and the second auxiliary guide wires 12b and 22b are not formed as deep and / or thick linear grooves, the opening success rate is 4 It was / 10. Originally, this starts tearing from the tip of the notch 15a, and after the tear reaches the first auxiliary guide lines 12a and 22a, the main guide lines 11 and 21 are along the first auxiliary guide lines 12a and 22a. Since the first auxiliary guide lines 12a and 22a are connected to the main guide lines 11 and 21 at a certain angle, the first auxiliary guide lines 12a and 22a should be guided to the first auxiliary guide lines 11 and 21 before reaching the guide lines 11 and 21. This is probably because there were cases where the lines 12a and 22a deviated.

On the other hand, as described above, the curved line portions 123 of the first auxiliary guide wires 12a and 22a and the second auxiliary guide wires 12b and 22b are deeper and / or thicker linear grooves than the other portions and the main guide wires 11 and 21, respectively. The following results were obtained for the packaging bag 100 formed as.

(1) Opening test conditions-Tearing from the left notch 15a to the back side and tearing to the front side-Tearing from the right notch 15b to the back side and tearing to the front side, respectively, with the front side film 100a facing upward and the back side film 100b was directed upwards.
Each tear was performed by the practitioner A for 2 bags, the practitioner B for 4 bags, and the practitioner C for 4 bags.
(2) Opening test results As shown in FIG. 10, all the opening tests showed no defective opening and a good opening state could be obtained.

From the results of the above opening test, the curved line portion 123 connecting to the main guide lines 11 and 21 of the first auxiliary guide lines 12a and 22a and the bay connecting to the main guide lines 11 and 21 of the second auxiliary guide lines 12b and 22b. Each of the curved portions 123 is formed as deep and / or thick linear grooves by processing (multiple irradiations of laser light) to make the degree of tearability larger than that of the other portions and the main guide lines 11 and 21 respectively. The tear guide weakening line 10 (first auxiliary guide line 12a, main guide line 11, second auxiliary guide line 22a) of the front side film 100a and the tear induction weakening line 20 (first auxiliary guide line 22a,) of the back side film 100b. It was found to be effective from the viewpoint that even if the main guide line 11 and the second auxiliary guide line 22b) are slightly deviated from each other, the package can be opened satisfactorily.

For example, tearing is started from the tip of the notch 15a, and after the tear reaches the first auxiliary guide lines 12a and 22a, the tear is guided to the main guide lines 11 and 21 along the first auxiliary guide lines 12a and 22a. Is desirable. However, since the first auxiliary guide lines 12a and 22a are connected to the main guide lines 11 and 21 at a certain angle, the first auxiliary guide lines 12a and 12a are connected before the tear reaches the main guide lines 11 and 21. It may deviate from 22a. In particular, when the tear induction weakening lines 10 and 20 including the first auxiliary guide wires 12a and 22b are formed so as to be displaced as shown in FIG. 9 due to the variation in production, the induction in different directions is performed on the front and back surfaces. Where necessary, the problem is that due to the orientation of the film and the slight difference in thickness between the tear-inducing weakening lines 10 and 20 on the front and back, the film is pulled to the superior side and one side deviates from the tear-inducing weakening lines 10 and 20. was there. Therefore, as confirmed in the opening test, this problem is solved by making the portion of the first auxiliary guide wires 12a and 22a including the connection points with the main guide wires 11 and 21 deeper and / or thicker. Was done.

The shapes of the first auxiliary guide wires 12a and 22a and the second auxiliary guide wires 12b and 22b are not limited to the above-mentioned shapes (see FIGS. 3 and 4), and the seal portions 16 and 17 (first joint portion, The shape may be any shape that extends away from the outer edge line side of the second joint), connects to the main guide lines 11 and 21 (including intersection), and returns toward the outer edge line side. Further, regarding the relationship between the first auxiliary guide lines 12a and 22a and the second auxiliary guide lines 12b and 22b and the main guide lines 11 and 21, the main guide lines 11 and 21 are the first auxiliary guide lines 12a and 22a and the second auxiliary guide lines 12a and 22a. If it is connected to the guide lines 12b and 22b, the ends of the main guide lines 11 and 12 pass through the first auxiliary guide lines 12a and 22a and the second auxiliary guide lines 12b and 22b as shown in FIG. Even in the (intersection state), the ends of the main guide lines 11 and 12 may be on the first auxiliary guide lines 12a and 22a and the second auxiliary guide lines 12b and 22b. Further, the tear induction weakening lines 10 and 20 may include any one of the first auxiliary guide lines 12a and 22a and the second auxiliary guide lines 12b and 22b.

Further, the method of forming the deep and / or thick linear grooves is not limited to irradiating the laser beam a plurality of times as described above. For example, a predetermined range (including intersections) including connection points (including intersections) of the first auxiliary guide lines 12a and 22b and the second auxiliary guide lines 12b and 22b with the main guide lines 11 and 21 mechanically by a cutter or the like (including intersections). For example, the curved line portion 123) may be processed so as to have a linear groove deeper and / or thicker than the other portions. Further, the processing for forming the deep and / or thick linear grooves may be performed on the entire first auxiliary guide wires 12a and 22a, and the second auxiliary guide wires 12b and 22b. In this case, the first auxiliary guide lines 12a and 22a and the second auxiliary guide lines 12b and 22b are formed as linear grooves deeper and / or thicker than the main guide lines 11 and 21, respectively, and the main guide lines 11 and 21 are formed. It can be easier to tear.

Further, the above-mentioned packaging bag 100 is not processed to make all of the tear-inducing weakening lines 10 and 20 deeper and / or thicker. If the whole is made thicker or the like, the strength of the tear-inducing weakening lines 10 and 20 decreases, so there is a high risk that the tear-inducing weakening lines 10 and 20 will tear during transportation, filling, and the like. In addition, the tear-inducing weakening lines 10 and 20 are conspicuous, which hinders the design of the packaging bag. From the viewpoint of production efficiency and economy, as described above, the tear induction weakening lines 10 and 20 are easily torn, such as being limited to a part or all of the first auxiliary guide lines 12a and 22a and the second auxiliary guide lines 12b and 22b. It is better that the number of parts to be processed to increase the degree of sagging is small, and the laser output is also low.

Further, when printing is performed on the packaging bag 100, the printing is scraped by laser processing. In particular, at the tear start portions (notches 15a and 15b), there are many prints related to the function of indicating the opening position, so it is desirable to avoid cutting the prints by laser processing as much as possible. In consideration of this, instead of performing a plurality of laser processing at intervals, as described above, one line of the first auxiliary guide lines 12a and 22a and the second auxiliary guide lines 12b and 22b, respectively, or It is preferable to perform special laser processing at a position slightly deviated.

The present invention is not limited to the above-described embodiments and modifications thereof. Various modifications can be made based on the gist of the present invention, and these are not excluded from the scope of the present invention.

The packaging bag according to the present invention has the effect that tearing from the tear start portion can surely proceed to the main guide wire connected to the auxiliary guide wire, and is useful as a packaging bag having easy opening property. Is.

10 1st tear guide weakening line 11 Main guide line 111 Straight part 112 Curved part 113 Straight part 12a 1st auxiliary guide line 12b 2nd auxiliary guide line 121, 125 Straight part 122, 124 Inclined part 125 Curved line part 15a Left notch 15b Right notch 16, 17, 18 Seal part 19 Plastic fastener 20 Second tear induction weakening line 21 Main induction wire 211, 212, 213 Straight line part 22a First auxiliary induction wire 22b Second auxiliary induction wire 100 Packaging bag 100a Front side film 100b Back side the film

Claims (9)

The first film and the second film are formed into a bag shape by joining the peripheral edges thereof, and the first tear is formed at the first joining portion formed by joining the peripheral edges of the first film and the second film. A packaging bag in which a start portion is formed and tear induction weakening lines for inducing tearing from the first tear start portion are formed on the first film and the second film, respectively.
The tear induction weakening line is
A main guide wire extending in a direction away from the first joint side,
Includes a first auxiliary lead wire that extends away from the outer edge line side of the first joint, connects to the main lead wire, and returns toward the outer edge line side.
The first auxiliary guide wire is a packaging bag having a portion in a predetermined range including a connection point with the main guide wire as a first special shape portion which is a linear groove deeper or thicker than the main guide wire. The packaging bag according to claim 1, wherein the portion of the predetermined range including the connection point of the first auxiliary guide wire with the main guide wire includes a curved wire portion that becomes convex in a direction away from the first joint portion side. .. The first or second aspect of claim 1 or 2, wherein the first auxiliary guide wire extends from the outer edge line of the first joint portion, connects with the main guide wire, returns to the outer edge line, and surrounds the first tear start portion. Packaging bag. A second tear start portion is formed at the second joint portion facing the first joint portion.
The tear-inducing weakening line further
A second auxiliary lead wire extending away from the outer edge line side of the second joint, connecting to the main lead wire and returning toward the outer edge line is included.
The second auxiliary guide wire has a portion in a predetermined range including a connection point with the main guide wire as a second special shape portion which is a linear groove deeper and / or thicker than the main guide wire. The packaging bag according to any one of 3 to 3. The packaging bag according to claim 4, wherein the portion of the predetermined range including the connection point of the second auxiliary guide wire with the main guide wire includes a curved wire portion that becomes convex in a direction away from the second joint portion. The fourth or fifth aspect of the present invention, wherein the second auxiliary guide wire extends from the outer edge line of the second joint portion, connects to the main guide wire, returns to the outer edge line, and surrounds the second tear start portion. Packaging bag. The first film and the second film are formed in a bag shape by joining the peripheral edges thereof, and a tear start portion is formed at the joint portion formed by joining the peripheral edges of the first film and the second film. A packaging bag in which tear-inducing weakening lines for inducing tearing from the tear-initiating portion are formed on the first film and the second film, respectively.
The tear induction weakening line is
The main guide wire extending in the direction away from the joint side,
A method for forming the tear induction weakening line in a packaging bag including an auxiliary guide wire extending in a direction away from the outer edge line side of the joint portion, connecting to the main guide wire and returning toward the outer edge line side. ,
It is a step of forming the tear-inducing weakening line to be formed on each of the first film and the second film as a linear groove by laser light irradiation.
The first step of forming the auxiliary guide line and
It has a second step of forming the main lead wire and
In the first step, a portion of a predetermined range including the connection point of the auxiliary guide line with the main guide line is irradiated with laser light more than the number of times of irradiation of the laser light at the time of forming the main guide line. A method of forming a tear-inducing weakening line, which comprises a step of forming by doing so. The first film and the second film are formed in a bag shape by joining the peripheral edges thereof, and a tear start portion is formed at the joint portion formed by joining the peripheral edges of the first film and the second film. A packaging bag in which tear-inducing weakening lines for inducing tearing from the tear-initiating portion are formed on the first film and the second film, respectively.
The tear induction weakening line is
The main guide wire extending in the direction away from the joint side,
A method for forming the tear induction weakening line in a packaging bag including an auxiliary guide wire extending in a direction away from the outer edge line side of the joint portion, connecting to the main guide wire and returning toward the outer edge line side. ,
It is a step of forming the tear-inducing weakening line to be formed on each of the first film and the second film as a linear groove by laser light irradiation.
The first step of forming the auxiliary guide line and
It has a second step of forming the main lead wire and
The first step is a step of irradiating a predetermined range portion of the auxiliary guide wire including a connection point with the main guide wire a plurality of times while shifting the portion at a pitch equal to or less than the spot diameter of the laser beam. A method of forming a tear-inducing weakening line, including. The first film and the second film are formed in a bag shape by joining the peripheral edges thereof, and a tear start portion is formed at the joint portion formed by joining the peripheral edges of the first film and the second film. A packaging bag in which tear-inducing weakening lines for inducing tearing from the tear-initiating portion are formed on the first film and the second film, respectively.
The tear induction weakening line is
The main guide wire extending in the direction away from the joint side,
A method for forming the tear induction weakening line in a packaging bag including an auxiliary guide wire extending in a direction away from the outer edge line side of the joint portion, connecting to the main guide wire and returning toward the outer edge line side. ,
It is a step of forming the tear-inducing weakening line to be formed on each of the first film and the second film as a linear groove by laser light irradiation.
The first step of forming the auxiliary guide line and
It has a second step of forming the main lead wire and
In the first step, the portion of the predetermined range including the connection point of the auxiliary guide wire with the main guide wire is covered with the portion of the predetermined range including the connection point of the auxiliary guide wire with the main guide wire. A method for forming a tear induction weakening line, which comprises a step of forming by irradiating a laser beam having an output larger than the output of the laser beam to be irradiated when forming the induction line.

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