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(11) | EP 1 106 338 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
| published in accordance with Art. 158(3) EPC |
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| (54) | CUTTING BLADE FOR BAG-MAKING DEVICE, BAG-MAKING DEVICE, METHOD OF MANUFACTURING PACKAGING BAG, AND PACKAGING BAG MANUFACTURED USING THE BAG-MAKING METHOD |
| (57) A cutting blade (5) of a bag-making device includes a cutting tooth (5A) formed along
a cutting direction of a package bag; and a notch-forming tooth (5B) orthogonal with
the cutting direction and provided on both sides of the cutting direction sandwiching
the cutting tooth (5A). Accordingly, simultaneously with cutting the package bag by
the cutting tooth (5A), the notch can be accurately formed without shifting the film
on one side in forming the notch, thus obtaining easy-openability. |
Technical Field
[0001] The present invention relates to a cutting blade of bag-making device for producing a package bag such as a plastic pouch used for light package article for packaging food etc., a bag-making device, a manufacturing method of a package bag by the bag-making device and a package bag manufactured by the manufacturing method.
Background Art
[0002] Conventionally, a plastic pouch formed by heat-sealing a periphery of two plastic films has been known, which is widely used as a light package article such as packaging food etc.
[0003] Since various materials such as liquid, slurry and powder is sealed in the plastic pouch, easy-openability as well as strength and gas-barrier property as a package material is required.
[0004] In order to satisfy such demand, (1) a pouch has been manufactured by forming at least either one of two plastic films by an easily-splittable film, or (2) a notch has been formed on a heat-sealing portion of the bag (Japanese Patent Laid-Open Publication No. Hei 01-111681).
[0005] However, (1) though the easily-splittable film is superior in linear cuttability, it is not suitable for a very small bag for sealing seasoning etc.
[0006] Further, (2) when a notch is formed, additional step for forming the notch is necessary after making the bag, thus deteriorating production efficiency.
Disclosure of the Invention
[0007] An object of the present invention is to provide a cutting blade for a bag-making device, a bag-making device, a manufacturing method of package bag by the bag-making device and a package bag manufactured by the manufacturing method capable of obtaining easy-openability irrespective of the size of the bag and capable of improving production efficiency.
[0008] A cutting blade of a bag-making device according to the present invention includes: a cutting tooth formed along a cutting direction of a package bag; and a notch-forming tooth orthogonal with the cutting direction and provided on both sides of the cutting direction sandwiching the cutting tooth.
[0009] According to the present invention, the package bag is cut by the cutting tooth along the cutting direction and the notch is formed by the notch-forming tooth. Since the notch-forming tooth is orthogonal with the cutting direction and is provided on both sides of the cutting tooth, the notch-forming tooth does not shift on one side in forming the notch, thus accurately forming the notch. Accordingly, the bag can be opened easily from the notch portion, and easy-openability can be obtained irrespective of the size of the bag. Further, since the notch can be formed simultaneously with cutting the bag, the separate step for forming the notch is not required, thus improving efficiency of production.
[0010] In the present invention, the bag-making device includes a packaging device. A plurality of the notch may preferably be formed at a predetermined pitch in a direction orthogonal with the cutting direction. The configuration of the cutting tooth and the notch-forming tooth is not restricted and any configuration is possible as long as the teeth can cut along the cutting direction and can form the notch in a direction orthogonal with the cutting direction. For instance, a cutting tooth continuously extending along the cutting direction and a notch-forming tooth may be formed on the cutting tooth orthogoanally with the cutting direction. Alternatively, a saw-tooth cutting tooth may be formed along the cutting direction and the notch-forming tooth extending therefrom toward the outside of the thickness of the cutting tooth may be formed. In this arrangement, the notch may preferably be a linear shape, but may be a V-notch.
[0011] In the cutting blade for a bag-making device according to the present invention, a line connecting the respective notch-forming teeth may preferably be orthogonal with the cutting direction.
[0012] Accordingly, since the notch-forming tooth is provided symmetrically on both sides sandwiching the cutting tooth, the notch can be formed without being shifted in a direction orthogonal with the cutting direction. Further, since the cutting tooth can be formed on a symmetrical position on both sides of the cutting tooth, the cutting blade can be easily made.
[0013] In the cutting blade for a bag-making device according to the present invention, the cutting tooth may preferably be composed of a plurality of saw-tooth blade pieces formed along the cutting direction, and the notch-forming tooth may preferably be configured by a ridgeline formed where two slanting surfaces formed on the respective blade pieces and slanting toward mutually different directions relative to the cutting direction meet with each other.
[0014] Accordingly, since each of the respective plurality of blade pieces of the cutting tooth is configured in a shape narrowing toward the tip end thereof in both width direction and thickness direction of the cutting blade, the cutting tooth can easily enter the continuous package bag, thus facilitating cutting. Further, by arranging the cutting blade to be vertically movable within any desired range, the perforation can be formed while lowering the cutting tooth as well as cutting the continuous package bag. Further, since the notch-forming tooth is formed by the ridgeline of the blade piece, the notch-forming tooth can be formed simultaneously with forming the cutting tooth, thus reducing trouble in manufacture.
[0015] In the present invention, the angle of the blade formed by mutually adjacent blade pieces is not restricted. Though the angle may be appropriately defined according to the material and thickness of the package bag (45 to 60 degrees, for instance), cutting ability can be enhanced with small angle.
[0016] A bag-making device according to the present invention has: a pair of film-feeding pinch roller for feeding a film for a package bag; a welder disposed on a downstream side in a feeding direction of the film for welding the film to form the package bag; and a cutter having a cutting blade for cutting the package bag into a unit, the cutting blade of the cutter comprising: a cutting tooth formed along a cutting direction of a package bag; and a notch-forming tooth orthogonal with the cutting direction and provided on both sides of the cutting direction sandwiching the cutting tooth.
[0017] According to the present invention, the heat-sealed package bag by the welder is cut by the cutting tooth of the cutter and the notch is formed by the notch-forming tooth. Since the notch is provided on both sides of the cutting tooth, the notch can be accurately formed without being shifted, thus obtaining easy-openability irrespective of the size of the bag. Further, since the notch can be formed simultaneously with cutting, the production efficiency of the bag-making device can be improved.
[0018] In the present invention, the welder may be operated according to heat-seal method, impulse seal, high-frequency sealing method and ultrasonic sealing method. The heat-seal method may be bar seal, rotary roll seal, belt seal etc.
[0019] A manufacturing method of a package bag according to the present invention includes: a film-feeding step for feeding a film for a package bag; a heat-welding step for sealing a periphery of the film of the package bag fed during the film feeding step to make a package bag; and a cutting step for cutting the continuous package bag made during the heat-welding step into a separate package bag using a cutting blade, the cutting blade comprising: a cutting tooth formed along a cutting direction of a package bag; and a notch-forming tooth orthogonal with the cutting direction and provided on both sides of the cutting direction sandwiching the cutting tooth.
[0020] In the present invention, since the continuously-formed package bag can be cut by the cutting tooth and the notch can be simultaneously formed by the notch-forming tooth, independent package bag can be manufactured efficiently.
[0021] A package bag according to the present invention is characterized in being obtained by the above-described manufacturing method of a package bag according to the present invention.
[0022] In the present invention, since the notch can be accurately formed on the package bag, the easy-openability can be obtained irrespective of the size of the bag.
Brief Description of Drawings
[0023]
Fig. 1 is an entire general view illustrating a bag-making device according to an embodiment of the present invention;
Fig. 2 is a front elevation showing a cutting blade according to the aforesaid embodiment;
Fig. 3 is a cross section taken along III-III line in Fig. 2 showing a primary portion of the cutting blade of the aforesaid embodiment;
Fig. 4 is a front elevation showing a package bag according to the aforesaid embodiment; and
Fig. 5 is a fragmentary view showing the cutting blade according to a modification of the present invention.
Best mode for Carrying out the Invention
[0024] An embodiment of the present invention will be described below with reference to attached drawings.
[0025] As shown in Fig. 1, a bag-making device 1 according to the present embodiment has a pair of film-feeding pinch roller for feeding a film 2 for the package bag, a horizontal heat-seal bar 4 and a support 4' thereof as a welder provided on the downstream side in a feeding direction of the film 2 fed from the film-feeding pinch rollers 3, 3 spaced apart by a predetermined interval, a preheating longitudinal heat seal bar 7 and a support 7' thereof provided on the downstream side in a feeding direction of the film 2 relative to the heat seal bar 4 and the support 4', a full-heating longitudinal heat-seal bar 8 and a support 8' thereof, a pair of film-stretching pinch roller 9 disposed on a downstream side in a feeding direction relative to heat-seal bar 8, and a cutting blade 5 as a cutter and a support 5' thereof provided on a downstream side in a feeding direction relative to the pinch roller 9.
[0026] The horizontal heat-seal bar 4 and the support 4', the full-heating longitudinal heat-seal bar 8 and the support 8', and the cutting blade are vertically movable relative to the film 2 at a predetermined time cycle. The cutting blade 5 can be stopped at any position in up and down direction.
[0027] Incidentally, though the preheating heat-seal bar 7 and the support 7' are fixed spaced apart at a predetermined gap sandwiching the film 2, the heat-seal bar 7 and the support 7' may be provided vertically adjustable.
[0028] The film 2 of the present embodiment is a laminated film with a gas-barrier film such as nylon and polypropylene and a linear low-density polyethylene film being laminated.
[0029] In the bag-making device 1, the two films 2 fed from the film-feeding pinch rollers 3, 3 are heat-sealed along the feeding direction of the film 2 by the pair of horizontal sealing heat-seal bar 4 vertically moving at a predetermined cycle, thus forming a bottom (head) of the package bag.
[0030] Subsequently, the preheating longitudinal heat-seal bar 7 and the full-heating longitudinal heat-seal bar 8 heat-seals the films orthogonally with the feeding direction of the package bag 11, which is cut in a predetermined length by vertically moving the cutting blade 5 at a predetermined cycle so as to form individual package bag 10 having an inlet 10A on one side thereof.
[0031] Incidentally, various materials such as spice are sealed in the inside of the package bag 10 and the inlet 10A is heat-sealed by a horizontal sealing heat-seal bar in a separate process.
[0032] The cutting blade 5 is made of a plate-shaped member as shown in Figs. 2 and 3, a tip end of the cutting blade 5 on the film 2 side being formed in a saw-tooth shape.
[0033] Specifically, the tip end of the cutting blade 5 has a cutting tooth 5A formed along a cutting direction of the package bag 10, and a notch-forming tooth 5B formed on both sides in a direction orthogonal with the cutting direction sandwiching the cutting tooth 5A. The cutting tooth 5A is aligned along the cutting direction and is composed of a plurality of blade pieces 5C with depth narrowing toward tip end thereof in width and thickness direction of the cutting blade 5. The notch-forming tooth 5B is formed on the respective blade pieces 5C and is configured by a ridgeline formed where the two slanting surfaces slanting in different directions relative to the cutting direction meet with each other.
[0034] The angle a and pitch P of the blade formed by mutually adjacent blade pieces 5C may be appropriately defined corresponding to the material of the film 2 for most suitable cutting (45 to 60 degrees, for instance), however, the angle a is preferably small for facilitating formation of the notch, thus facilitating cutting.
[0035] The cutting blade 5 is vertically movable within a desired range and the continuous bag 11 is cut to form the independent bags 10 when the cutting blade 5 is lowered to its maximum to continue the cutting tooth 5A. On the other hand, when the cutting tooth 5A enters only a predetermined depth, the bag 11 is not completely cut and perforation is formed.
[0036] As shown in Fig. 4, the package bag 10 has a cutting line 20 and a notch 21 formed orthogonal with the cutting line 20. The cutting line 20 is formed by the cutting tooth 5A and the notch 21 is formed by the notch-forming tooth 5B.
[0037] The length L of the notch 21 is the same as a dimension L of half of the thickness of the cutting blade 5 as shown in Fig. 3. The notch 21 is within the range of a heat-sealed portion 22. Various materials such as liquid, slurry and powder are sealed within an accommodating portion 23 of the package bag 10.
[0038] According to the present embodiment, following effect can be obtained.
(1) The package bag 10 is cut by the cutting tooth 5A along the cutting direction and the notch is formed by the notch-forming tooth 5B. Since the notch-forming tooth 5B is orthogonal with the cutting direction and is provided on both sides of the cutting tooth 5A, the notch-forming tooth 5B does not shift on one side in forming the notch, thus accurately forming the notch. Accordingly, the bag can be opened easily from the notch portion, and easy-openability can be obtained irrespective of the size of the bag. Further, since the notch can be formed simultaneously with cutting the bag, the separate step for forming the notch is not required, thus improving efficiency of production.
(2) Since the notch-forming tooth 5B is provided symmetrically on both sides of the cutting tooth 5A, the notch can be formed without being shifted in a direction orthogonal with the cutting direction. Further, since the cutting tooth can be formed on a symmetrical position on both sides of the cutting tooth, the cutting blade can be easily made.
(3) Since each of the respective plurality of blade pieces 5C of the cutting tooth 5A is configured in a shape narrowing toward the tip end thereof in both width direction and thickness direction of the cutting blade 5, the cutting tooth can easily enter the continuous package bag 11, thus facilitating cutting.
(4) Since the notch-forming tooth 5B is formed by the ridgeline of the blade piece 5C, the notch-forming tooth 5B can be formed simultaneously with forming the cutting tooth 5A, thus reducing trouble in manufacture.
(5) Since the cutting blade 5A is vertically movable within any desired range, the perforation can be formed while lowering the cutting tooth 5A as well as cutting the continuous package bag 20, thus widening application range thereof.
(6) According to the manufacturing method of the package bag, since the continuously-formed package bag 11 can be cut by the cutting tooth 5A and the notch can be simultaneously formed by the notch-forming tooth 5B, independent package bag can be manufactured efficiently.
(7) Since the notch 21 can be accurately formed on the package bag, the easy-openability can be obtained irrespective of the size of the bag.
[0039] Incidentally, the scope of the present invention is not limited to the above-described embodiment, but includes following modifications as long as an object of the present invention can be attained.
[0040] As shown in Fig. 5, a notch-forming tooth 15B is lengthened relative to the notch-forming tooth 5B of the above-described embodiment by L1 in the present embodiment. In this example, the end of the notch-forming tooth 5A remote from the cutting tooth 5A is extended to a position adjacent to an extension of the recess of the cutting tooth 5A. Accordingly, since the angle of the notch-forming tooth 15B in the thickness direction of the cutting blade 5 is made steep, the cutting blade 5 can easily enter the continuous package bag 20, thus facilitating cutting and formation of the notch.
[0041] Though the bag-making device 1 according to the above-described embodiment has a preheating heat-seal bar 7 and full-heating heat-seal bar 8 disposed on the downstream side of the feeding direction of the film 2 relative to the horizontal heat-seal bar 4, the disposition of the heat-seal bar is not restricted to such arrangement. For instance, after the bottom and head along the feeding direction of the film are heat-sealed by an opposing horizontal heat-seal bar, the independent package bag may be formed by heat-sealing with the preheating heat-seal bar and full-heating heat-seal bar, and, subsequently, a position remote from the heat-sealed portion may be cut by the full-heating heat-seal bar by the cutting blade, thus forming an inlet at the cut portion.
Industrial Availability
[0042] The present invention relates to a cutting blade of bag-making device, a bag-making device, a manufacturing method of a package bag by the bag-making device and a package bag manufactured by the manufacturing method, which can be suitably used for producing a package bag such as a plastic pouch used for light package article for packaging food etc.
a cutting tooth formed along a cutting direction of a package bag; and
a notch-forming tooth orthogonal with the cutting direction and provided on both sides of the cutting direction sandwiching the cutting tooth.
a pair of film-feeding pinch roller for feeding a film for a package bag;
a welder disposed on a downstream side in a feeding direction of the film for welding the film to form the package bag; and
a cutter having a cutting blade for cutting the package bag into a unit,
the cutting blade of the cutter comprising: a cutting tooth formed along a cutting direction of a package bag; and a notch-forming tooth orthogonal with the cutting direction and provided on both sides of the cutting direction sandwiching the cutting tooth.
a film-feeding step for feeding a film for a package bag;
a heat-welding step for sealing a periphery of the film of the package bag fed during the film feeding step to make a package bag; and
a cutting step for cutting the continuous package bag made during the heat-welding step into a separate package bag using a cutting blade,
the cutting blade comprising: a cutting tooth formed along a cutting direction of a package bag; and a notch-forming tooth orthogonal with the cutting direction and provided on both sides of the cutting direction sandwiching the cutting tooth.
a film-feeding step for feeding a film for a package bag;
a heat-welding step for sealing a periphery of the film of the package bag fed during the film feeding step to make a package bag; and
a cutting step for cutting the continuous package bag made during the heat-welding step into a separate package bag using a cutting blade,
the cutting blade comprising: a cutting tooth formed along a cutting direction of a package bag; and a notch-forming tooth orthogonal with the cutting direction and provided on both sides of the cutting direction sandwiching the cutting tooth.