JP2001179474A - Method of forming perforation for seal opening - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of forming perforations by a laser beam on a laser beam absorbing layer of a laminated film for a seal opening, on which layer the cut line is not much noticeable. SOLUTION: In a method where perforations are formed by a laser beam on a laser beam absorbing layer of a laminated film provided with a laser beam absorbing layer and a layer of thermally adhesive resin, the method of forming perforations for opening seal is characterized by a process in which the laminated film is irradiated by a laser beam while the laminated film is in contact with a cooled supporting body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming an opening score line by irradiating a laminated film for producing a packaging bag with a laser.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a score line in at least one layer of a multilayer structure having a multilayer structure, as described in US Pat. No. 3,790,744, at least one synthetic resin layer is formed. A method of forming a linear cut line in at least one layer including the synthetic resin layer of the laminate in a direction parallel to the flow of the laminate by irradiating a laser with the laminate including the laminate rolled along a support roll. Are known. However, in the above method, since the layer adjacent to the layer where the score line of the laminate is formed is heated and irregularities corresponding to the score line are generated, the location of the formed score line is often from the outer surface of the laminate. There is a disadvantage that the appearance of the noticeable laminate is deteriorated. In particular, when the score line is formed in the laminate including the aluminum foil layer, irregularities are generated in the aluminum foil layer corresponding to the positions of the formed score lines, and the irregularities become more conspicuous from the outer surface of the laminate. Therefore, there is a disadvantage that the design of the packaging bag made of the laminate is deteriorated.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for forming a score line for opening which is not noticeable even when a score line is formed in the laminated film and does not deteriorate the design.

[0004]

SUMMARY OF THE INVENTION In a method of forming a score line by laser in a laser absorption layer of a continuous laminated film provided with a laser absorbing layer and a heat-adhesive resin layer, the laminated film is brought into contact with a cooling support. By forming a cut line in the laser absorption layer by irradiating the laser in a state, unevenness is generated by heat when forming the cut line in the cut line portion in the layer adjacent to the laser absorption layer. Can be reduced. Therefore, the portions where the score lines are formed are less noticeable, and the appearance of the laminated film can be improved.

[0005] In the above method of forming a score line for opening,
A packaging bag in which a continuous cut line having a predetermined shape is formed at a predetermined position by intermittently moving a continuous laminated film by a predetermined distance, stopping the continuous film, and forming a linear cut line in a transverse direction of the multilayer film. In addition to the production of a laminated film for producing the same, it is possible to reduce unevenness generated at the part of the score line.

[0006] In the above method of forming a score line for opening,
The laminated film is composed of an outer layer, an aluminum foil layer, a laser absorbing layer, and a thermo-adhesive resin layer, and the laser is irradiated from the thermo-adhesive resin layer surface in a state where the outer layer of the laminated film is in contact with the cooling support. In general, in the case of a laminated film including an aluminum foil layer, irregularities are easily generated and conspicuous in the aluminum foil layer corresponding to the formed cut line, but the unevenness of the aluminum foil layer corresponding to the formed cut line is Since the occurrence of cracks can be reduced, the score lines are less noticeable and the design is not deteriorated.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view schematically showing a method of forming a score line for opening according to the present invention, FIG. 2 is a plan view showing a continuous laminated film in which a score line is formed, and FIG. 3 is manufactured using the laminated film shown in FIG. FIG. 4 is a cross-sectional view showing the configuration of the laminated film, FIG. 5 is a cross-sectional view showing another configuration of the laminated film, 1 is a cooling roll, 2 is a guide roll, and 3 is laser irradiation. Device, 4 is the score line, 5a,
5b is an edge thermal bonding portion, 5a 'and 5b' are edge thermal bonding regions, 6 is a side edge thermal bonding portion, 6 'is a side edge thermal bonding region, 7 is a cut, 8 is a fold line, and 9 is a cut. Wire, 10 is a laminated film, 11 is an outer layer, 12,
Reference numerals 14, 16 denote an adhesive layer, 13 denotes an aluminum foil layer, 15 denotes a laser absorption layer, and 17 denotes a thermoadhesive resin layer.

The outline of the method for forming a score line for opening according to the present invention is as shown in FIG. 1, and using a device provided with a cooling roll 1, a guide roll 2, and a laser irradiation device 3,
In a state where the laminated film 10 is passed through the guide roll 2 and brought into contact with the surface of the cooling roll 1, the laminated film 10 is intermittently moved by a certain distance and stopped, and the laminated film 10 is cooled by the cooling roll 1. The laser beam emitted from the laser irradiation device 3 is moved in the flow direction and the transverse direction of the laminated film 10 to form a fold line 4 in the transverse direction of the laminated film 10. As a laser, the wavelength that is easily absorbed by the plastic layer is 10.6 μm
A carbon dioxide laser is used.

Although not shown, the inside of the laser irradiation device 3 includes a laser generator, a Z-axis scanner (dynamic focus), an objective lens, an X-axis scanner, and a Y-axis scanner. After adjusting the focal length by the axis scanner and passing through the objective lens, the laser is moved in the flow direction and the transverse direction of the laminated film 10 by the X-axis scanner and the Y-axis scanner, and the laser is moved to a predetermined position on the laminated film 10. It is configured so that a score line can be formed in the shape. As a laser irradiation apparatus used in the present invention, for example, HPLK1130-6 (GENERAL S
CANNING).

The cooling roll 1 used in the present invention has a diameter of 500 to 1000 mm having a surface cooled to about 20 to 25 ° C. which does not condense on the surface of the cooling roll 1.
A metal roll made of stainless steel, iron, aluminum or the like is used. If the diameter of the cooling roll 1 is small, the curvature of the surface becomes large, and the focus error becomes large when the laser is moved in the flow direction of the laminated film 10, which is not preferable. The diameter of the cooling roll 1 is 1000 mm,
The distance from the XY scanner to the target is about 500
In the case of mm, the score line 4 can be formed in the laminated film 10 within a range of about 300 mm in the transverse direction and about 150 mm in the flow direction.

In order to form the score line 4 in the laser absorbing layer of the laminated film by irradiating a laser beam, the laminated film shown in FIG. 4 or the outer layer 11 of the laminated film shown in FIG. And output a carbon dioxide gas laser from the side of the heat-adhesive resin layer 17 of the laminated film 5.
By irradiating under the conditions of 0 W, 200 μsec repetition, 80 μsec pulse width, and 1000 to 1500 mm / sec scan speed, the laser of the laser absorption layer 15 laminated on the heat-adhesive resin layer 17 via the adhesive layer 16 is used. The cut portion 4 can be formed by melting and mist of the irradiated portion. The cut line 4 can be formed by irradiating a laser at a scan speed of 1000 to 1500 mm / sec. However, if the scan speed is low, the cut line is good, but the cut line becomes slightly noticeable, and if the scan speed is high, the cut line is cut. The entry of the line of vision becomes slightly worse, but the line of the cut line becomes inconspicuous.

The continuous laminated film 10 shown in FIG. 2 in which the score lines 4 are formed is for producing the four-sided sealing packaging bag shown in FIG. 3, and is a continuous laminated film having a constant width. The both side end portions and the center portion in the width direction of 10 are side end heat bonding regions 6 ′, respectively, and are cut lines 9 for cutting at intervals corresponding to the length in the vertical direction of the packaging bag. Both sides sandwiching 9 are an edge thermal bonding area 5a 'and an edge thermal bonding area 5b', and a linear score line 4 is formed in the transverse direction of the laminated film 10 at a position away from the cut line 9 by a predetermined distance. Configuration. Cuts are formed at both ends of the cut line 4 of the laminated film 10 shown in FIG. 2, and the cuts can be formed simultaneously in the step of forming the cut lines 4 by a laser, or in another step. It can also be formed mechanically. When the cuts are formed simultaneously in the step of forming the score lines 4, the laminated film 10 is irradiated by irradiating a carbon dioxide laser under the conditions of an output of 50 W, a repetition of 200 μsec, a pulse width of 80 μsec, and a scan speed of 200 to 300 mm / sec. Can be completely melted and mist-formed to form cuts.

The continuous laminated film on which the score line 4 shown in FIG. 2 is formed is folded and folded at the fold line 8 at the center in the width direction, and the side end heat bonding areas 6 'on both sides are thermally cut. The packaging bag according to the embodiment is obtained by forming a tubular shape by bonding the side edge thermal bonding portions 6 to each other, cutting the edge thermal bonding region 5b 'with the cutting line 9 after the thermal bonding. After filling the contents into the packaging bag, the edge thermal bonding region 5a 'is thermally bonded to form a thermal edge thermal bonding portion 5a, whereby a four-side seal bag as shown in FIG. 3 is obtained. Further, the continuous laminated film on which the score line 4 shown in FIG. 2 is formed is applied to an automatic filling and packaging machine, and is folded in two at the score line 8 to form a side end heat bonding area 6 ′.
3 is thermally bonded, the contents are filled, and the edge thermal bonding region 5a 'and the edge thermal bonding region 5b' are thermally bonded, and then cut at the cut line 9 to obtain the packaging bag shown in FIG. be able to. In order to open this packaging bag, the side end heat bonding portion 6
By tearing the packaging bag from the portion of the cut 7 along the score line 4, the upper portion of the packaging bag can be easily opened.

In the embodiment, the shape of the packaging bag is a four-sided sealing bag, and the straight cut line 4 parallel to the edge thermal bonding portion 5a is formed. However, the shape of the packaging bag is a three-sided sealing bag. , Pillow-type bags, pillow-type gusset bags, self-standing bags, etc. are arbitrary. The shape of the score line 4 to be formed is not limited to a linear shape, but may be a folded line shape, a curved shape, a diagonal shape, etc. It is possible to make the shape easy to open corresponding to the above. Further, instead of forming the score line 4 over the entire length of the continuous laminated film in the width direction as in the embodiment, it is also possible to partially form the score line in the width direction in an arbitrary shape. By forming a score line in a half width in the width direction without forming the entire length in the width direction of the laminated film, the score line is formed only in the laminated film constituting the back surface of the packaging bag, and the cut line is not conspicuous from the surface. It can also be a bag.

As shown in FIG. 4, the laminated film for forming the score line 4 by the method of the present invention includes an outer layer 11, an adhesive layer 12, an aluminum foil layer 13, an adhesive layer 14, and a laser absorbing layer 15 in this order from the outer surface. And a heat-adhesive resin layer 16, as shown in FIG. 5, the outer layer 11, the adhesive layer 12, and the laser absorbing layer 15.
And the heat-adhesive resin layer 16 are laminated, and the score line 4 is formed in the laser absorbing layer 15. With the outer layer 11 of the laminated film in close contact with the surface of the cooling roll,
By irradiating the carbon dioxide gas laser from the surface of the thermal adhesive resin layer 16, the thermal adhesive resin layer 16 transmits the carbon dioxide laser without absorbing much, so that the laser absorbing layer 15 inside the thermal adhesive resin layer 16 is formed. Absorbs the carbon dioxide gas laser to form a score line 4.

As the outer layer 11 of the laminated film, biaxially oriented polyethylene terephthalate, biaxially oriented polypropylene,
Biaxially stretched nylon or the like can be used. As the laser absorbing layer, biaxially stretched polyethylene terephthalate, biaxially stretched nylon, biaxially stretched polyvinyl alcohol, polycarbonate, or the like can be used. These plastics have a wavelength of 1
Concentrates the carbon dioxide laser and irradiates it on the surface of the laser absorption layer 15 so that the irradiated part of the laser absorption layer 15 generates heat, melts, decomposes, and mist. And the score line 4 is formed. As the heat-adhesive resin layer 17, polyolefin resins such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, and ethylene-propylene copolymer can be used. Since these resins have the property of transmitting the carbon dioxide laser without absorbing it, the cut line 4 is not formed even when the carbon dioxide laser is irradiated.

As for the structure of the laminated film, biaxially oriented polypropylene (OP
P) / Aluminum foil (AL) / Biaxially oriented polyethylene
Terephthalate (PET) / Polyethylene (PE), P
ET / AL / PET / polypropylene (PP), PET
/ AL / biaxially stretched nylon (0N) / PE, PET / A
L / ON / PP, PET / AL / ethylene-vinyl alcohol
Cole copolymer (EVOH) / PE, ON / AL / PE
T / PE, etc., but not including aluminum foil, PET / PET / PE, PET / ON / PE, PE
T / PET / PP, PET / EVOH / PE, OPP /
PET / PE and the like. In the above structure, the underlined layer absorbs the carbon dioxide laser to form a score line. As an adhesive layer for laminating each layer, a urethane-based adhesive is used in the case of dry lamination, and a polyethylene or the like is used in the case of extrusion lamination.

[0018]

According to the method for forming a score line by a carbon dioxide laser on a laser absorbing layer of a continuous laminated film provided with a laser absorbing layer and a heat-adhesive resin layer, the laser is applied while the laminated film is in contact with a cooling support. Irradiation can reduce the occurrence of unevenness in the portion corresponding to the cut line of the layer adjacent to the laser absorption layer due to the heat generated when the cut line is formed in the laser absorption layer. The portion where the line of sight is formed becomes less noticeable, and the appearance of the laminated film can be improved. In the method of forming the opening score line described above, the continuous laminated film is intermittently moved by a predetermined distance and stopped, and a method of forming a linear score line in the transverse direction of the laminated film to obtain a predetermined shape. A cut line can be formed at a predetermined position of the packaging bag, and the packaging bag can be obtained in which the score line is not conspicuous and the design property does not deteriorate. In the above-described method for forming a score line for opening, the laminated film is composed of an outer layer, an aluminum foil layer, a laser absorbing layer, and a thermo-adhesive resin layer, and the thermo-adhesive resin is in a state where the outer layer of the laminated film is in contact with a cooling support. By irradiating the laser from the layer surface, in general, in the case of a laminated film including an aluminum foil layer, irregularities are easily generated and conspicuous in the aluminum foil layer corresponding to the formed score line. Therefore, the occurrence of unevenness of the aluminum foil layer corresponding to the above can be suppressed, so that the score line is less noticeable and the design property does not deteriorate.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a method for forming a score line for opening according to the present invention.

FIG. 2 is a plan view showing a continuous laminated film on which a score line is formed.

FIG. 3 is a plan view showing a packaging bag made of the laminated film shown in FIG. 2;

FIG. 4 is a cross-sectional view illustrating a configuration of a laminated film.

FIG. 5 is a sectional view showing another configuration of the laminated film.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cooling roll 10 Laminated film 2 Guide roll 11 Outer layer 3 Laser irradiation device 12, 14, 16 Adhesive layer 4 Cut line 13 Aluminum foil layer 5a, 5b Edge thermal bonding part 15 Laser absorption layer 5a ', 5b' Edge thermal bonding Area 17 Heat-adhesive resin layer 6 Side-end heat-adhesive part 6 'Side-end heat-adhesive area 7 Cut 8 Fold line 9 Cut line

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E064 AE01 BA17 BA18 BA27 BA28 BA30 BA36 BB03 BC18 BC20 HP01 4E068 AF00 CB06 CF00 DB14

Claims (3)

[Claims] 1. A method of forming a score line by a carbon dioxide laser on a laser absorbing layer of a continuous laminated film provided with a laser absorbing layer and a heat-adhesive resin layer, wherein the laminated film is brought into contact with a cooling support. Irradiating a laser with a cutting line. 2. The opening according to claim 1, wherein the continuous laminated film is intermittently moved by a predetermined distance and stopped, and a linear cut line is formed in a transverse direction of the laminated film. The method of forming the score line. 3. The laminated film comprises an outer layer, an aluminum foil layer, a laser absorbing layer, and a thermo-adhesive resin layer, and a surface of the thermo-adhesive resin layer in a state where the outer layer of the laminated film is in contact with the cooling support. The method for forming a score line for opening according to claim 1 or 2, wherein a laser beam is irradiated from the opening.