JP2003291090A - Web cutting method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a web cutting method and device capable of eliminating a selvage fold by suppressing generation of wrinkles when a web is subjected to selvage cutting. <P>SOLUTION: A shear blade is formed from an upper round blade 20 and a lower round blade 21, wherein a web guide 22 is installed in a position of the lower round blade 21 mating with web guide surfaces 41 and 42. The web guide 22 is furnished with a spreading guide surface 55a and a web holddown guide surface 55b, whose length L1 in the web width direction is made 20 mm. When the web 12 is to be cut, the web guide 22 is pressed to the web holddown guide surface 42 of the lower round blade 21. There is no risk that the side edges of the web 12 wrinkle, and generation of a selvage fold can be suppressed. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a web cutting device and method for cutting a relatively wide flexible belt-like support (hereinafter referred to as a web) such as a film which is continuously fed in a feeding direction. Is.

[0002]

2. Description of the Related Art In recent years, thin transparent plastic films have been used as protective films for polarizing plates of liquid crystal displays, optical compensation films such as retardation films, plastic substrates, photographic supports,
Alternatively, demand is increasing as an optical material such as a moving picture cell, an optical filter, and an OHP film.

In particular, recently, liquid crystal displays have been improved in quality and are lightweight and highly portable, so that personal computers, word processors, portable terminals, televisions, digital still cameras, movie cameras, etc. However, a polarizing plate is indispensable for displaying images in this liquid crystal display. Then, along with the improvement of the quality of the liquid crystal display, it is required to improve the quality of the polarizing plate, and at the same time, the transparent plastic film which is the protective film of the polarizing plate is also required to have higher quality.

Regarding films for optical use such as protective films for polarizing plates, high transparency, low optical anisotropy, flatness, easy surface treatment, high durability (dimensional stability, dimensional stability, Moisture and heat resistance, water resistance), no foreign matter in the film and on the surface, no scratches on the surface and scratch resistant (scratch resistance), moderate film rigidity (handling), and appropriate water permeability It is said that it is necessary to have various characteristics such as sex.

The raw materials of the film having these characteristics are
Cellulose ester, norbornene resin, acrylic resin, polyarylate resin, polycarbonate resin and the like can be mentioned, but cellulose ester is mainly used from the viewpoints of productivity and material cost. In particular, the film of cellulose triacetate has extremely high transparency, and
Since it has a small optical anisotropy and a low retardation, it is particularly advantageously used for optical applications.

As a method for forming these films, various film forming techniques such as a solution film forming method, a melt film forming method, and a rolling method can be used, but they have good flatness and low optical anisotropy. Solution casting methods are particularly suitable for obtaining.
The solution film-forming method is a polymer solution in which raw material flakes are dissolved in a solvent and various additives such as a plasticizer, an ultraviolet absorber, an anti-degradation agent, a slip agent, and a peeling accelerator are added as necessary ( Hereinafter referred to as a dope), and the dope is cast on a support such as a horizontal endless metal belt or a rotating drum by a dope supply means (hereinafter referred to as a casting die), and then the support This is a method in which the solvent is removed by drying the film to a certain extent above, peeling the self-supporting film to which rigidity has been imparted from the support, and then passing the film through a drying section by various conveying means.
The formed film is dried on a solvent and then wound on a winding reel.

In a usual processing and cutting device, the blade can be fixed at the cutting position before feeding the web, but in the casting device, the web is continuously formed. The blade must be moved to the edge cutting position while cutting with the shear blade. By the way, there is a demand for light-weight, thin films for polarizing plates.
When the film is thin, wrinkles are likely to occur when cutting with a shear blade. When this wrinkle occurs, the ears may be broken and the cutting may occur. In this case, there is a problem that the casting is stopped and the film forming line is stopped.
For this reason, at present, when changing the width of the product, the film-forming speed is lowered to a predetermined speed after moving the shear blade to the edge cutting position while cutting with the shear blade. There is a problem that the product loss due to the decrease of

The present invention has been made to solve the above problems, and provides a web cutting method and apparatus capable of cutting a thin web or generating wrinkles without increasing wrinkles even if the production speed is increased. The purpose is to provide.

[0009]

To achieve the above object, the present invention provides a cutter having an upper round blade and a lower round blade.
A web cutting device that moves from the side edge of the web being fed toward the center of the web to cut into the web, and cuts the web in the feed direction, wherein the upper round blade or the lower round blade is the circumferential surface on the web side. And a web guide for guiding the web to a cutting position by an upper round blade and a lower round blade, and a biasing means for biasing the web guide to the circumferential surface on the web side. There is.

The web guide is provided with a guide surface for guiding the side edge of the web, and this guide surface is preferably composed of a spreading guide surface and a web pressing guide surface. Further, it is preferable that the expanding guide surface is composed of a bulging curved surface, and the web pressing guide surface is composed of a flat surface.

The length of the web pressing guide surface in the width direction of the web is preferably 15 mm or more. The web guide has a friction coefficient of 0.13 or less, such as PET (polyethylene terephthalate).
It is preferably composed of Further, it is preferable that the biasing means biases the web guide at 1 to 50 mN.

Further, in the web cutting method of the present invention, a cutter composed of an upper round blade and a lower round blade is moved from the side edge of the feeding web toward the center of the web to cut into the web,
In the web cutting method of cutting the web in the feed direction,
A web guide provided at a position facing the peripheral surface on the web side, which is the upper round blade or the lower round blade, moves the web side edge portion at the time of cutting to the cutting position by the upper round blade and the lower round blade. Characterized by giving guidance. The cutting method of the present invention can be applied to webs made of various materials, and is preferably used for a method of cutting a cellulose triacetate (TAC) film, particularly a TAC film for electronic displays. The web has a curl amount of ±
20 mm or less, base thickness 20 to 150 μm, flexural modulus 3900 to 5100 MPa, Young's modulus 2200 to
2900 MPa, and the feed rate is 20 to 120 m
/ Min is preferred. In the present invention, the curl amount is represented by the distance of the most protruding portion with respect to the line connecting both ends in the web width direction.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 1, a web edge cutting device 10 embodying a web cutting device of the present invention feeds both ears 12a of a web 12 fed from a film forming line 11. Is to cut in the direction, and the shear blade 13
The shear blade 13 is configured to include a shift unit 14 that moves the shear blade 13 in the width direction of the web 12. In addition, the knurling device 15 is provided on the upstream side of the web edge trimming device 10 and in the vicinity thereof.
Is provided. The knurling device 15 is provided with an embossing roller 16, and knurls the web 12 near the ears 12a by fine knurling to give the knurling 12b. In the web edge cutting device 10,
The ear portion 12a is cut off at a position outside the knurling 12b. The web 12 from which the ears 12a have been cut off is wound into a roll by the web winding device 17 in a state where the winding deviation is suppressed by the knurling 12b. The knurling device 15 may be provided after the shear blade 13. Further, the separated ear portion (ear scrap) 12a is collected and reused.

As shown in FIGS. 2 and 3, the shear blade 13
Is provided with an upper round blade 20, a lower round blade 21, and a web guide 22. These are made movable by the shift portion 14 in the width direction of the web 12.

The upper round blade 20 includes a blade body 25 and a blade holder 2
6, a housing unit 27, and a rotation drive unit 28. A blade holder 26 is rotatably mounted in the housing unit 27. The blade holder 26 includes a mounting shaft 30 and a blade retainer 31. The blade body 25 is formed in a disc shape, and is attached to the attachment shaft 30 by a blade retainer 31. The blade retainer 31 has a retainer spring 32, and the retainer spring 32 urges the blade body 25 toward the mounting shaft 30.

The housing unit 27 includes a rotary drive unit 2
8 is attached. The rotation drive unit 28 is a motor 35.
And a reduction gear 36, and rotates the mounting shaft 30. Further, the housing unit 27 includes a blade cover 3
7 is attached.

As shown in FIG. 3, the lower round blade 21 has a circumferential groove 40 into which the blade body of the upper round blade 20 enters and contacts.
A blade is formed on the side wall 40a of the circumferential groove 40, and the blade body of the upper round blade 20 comes into contact with this blade, and this contact portion becomes the cutting position of the web 12. In addition, the lower round blade 21 has a peripheral surface on the side where the side edge 12c of the web 12 enters at the time of cutting,
A tapered guide surface 41 and a cylindrical guide surface 42 are formed.

The housing unit 27 is provided with the web guide 22 via a mounting bracket 45. The web guide 22 includes the guide body 50 and the holding shaft 5.
1, a holder 52, and a cylinder 53. As shown in FIG. 4, the guide body 50 is arranged at a position facing the guide surfaces 41, 42 of the lower round blade 21, and has a guide surface for guiding the web side edge 12c to the cutting position on the lower surface. 55 is formed. This guide body 5
0 is for smoothly guiding the web 12 to the cutting position,
It is composed of PET.

As shown in FIG. 4, the guide surface 55 is formed of an expanding guide surface 55a and a web pressing guide surface 55b. The expansion guide surface 55a is formed of a bulging curved surface, and the web pressing guide surface 55b is formed of a flat surface. This web pressing guide surface 55b
Has a length L1 in the width direction of the web 12 of preferably 15 mm or more, more preferably 20 mm or more. 1
If it is less than 5 mm, the web cannot be pressed stably. The distance L2 between the end surface of the web pressing guide surface and the blade body 25 of the upper round blade 20 is preferably 0.1 to 5 mm. If this distance L2 is less than 0.1 mm, it may come into contact with the blade 25, and if it exceeds 5 mm, the web 12 does not stably enter the cutting point and wrinkles occur, and in some cases, the web 12 is cut.

As shown in FIG. 2, two holding shafts 51 are fixed to the upper portion of the guide body 50.
1 is attached to a holder 52 so as to be vertically movable. Further, a coil spring 56 is contracted to the holding shaft 52,
The coil spring 56 urges the guide body 50 downward. The holder 52 is fixed to the rod 53a of the cylinder 53 via an L-shaped bracket 57. Cylinder 5
3, the rod 53a is configured to be vertically movable by air drive. Then, as shown in FIGS. 5 and 6, when the rod 53a projects, the guide body 50 descends, and the coil spring 56 biases the guide surface 4 of the lower round blade 21.
The web pressing guide surface 55b of the guide main body 50 is pressed against 2.

The pressing force of the coil spring 56 when the guide body 50 is lowered is set to 10 mN. The pressing force is preferably in the range of 1 to 50 mN, more preferably 3 to 10 mN. This pressing force is 1
If it is less than mN, the pressing effect cannot be obtained, and it is 50 m.
When N is exceeded, the pressing force is so strong that the web 12 does not enter the cutting point, wrinkles occur, and the web 12 may be cut in some cases.

In the above embodiment, the web guide 22 is arranged on the upper round blade 20 side, but instead of this, the web guide 22 may be arranged on the lower round blade 21 side. In this case, a web guide surface against which the web guide 22 is pressed is formed on the upper round blade 20 side. Further, in the above embodiment, the shear blade 13 in which the upper round blade 20 is brought into contact with the lower round blade 21
However, in addition to this, the present invention may be applied to a cutter of a system in which the upper round blade is slightly separated from the lower round blade and is cut without contact. Further, although the web guide is made of PET, it is not limited to PET and may be any one that can smoothly guide the web 12. For example, a friction coefficient of 0.13 or less is preferably used. Further, instead of forming the web guide with PET, a material having good sliding property such as PET may be lined only on the guide surface.

Next, the operation of this embodiment will be described. The shear blade 13 is moved toward the center of the web 12 by the shift portion 14 due to a change in the product width of the web 12.
Prior to this movement, first, the cylinder 53 descends to press the guide body 50 against the guide surface 41 of the lower round blade 21. In this state, the shear blade 13 is fed toward the central portion of the web 12. At this time, since the web side edge portion is pressed by the web guide 22 and guided to the cutting portion, the occurrence of wrinkling of the web is suppressed, and the edge cutting due to the wrinkling does not occur. When the cutting is completed in this way, the cylinder 53 moves up and the web guide is moved to the retracted position. After that, the trimming is continued. In addition,
The thickness of the web 12 in the present invention is preferably 20 to 200 μm, more preferably 35 to 90 μm. Further, the feed rate of the web 12 of the present invention is preferably high.
If it exceeds 0 m / min, the effect becomes more remarkable.

[0024]

EXAMPLES Next, examples of the present invention will be described. As shown in FIG. 4, the length L1 of the web pressing guide surface 55b in the web width direction was 20 mm, and the guide body 50 was made of PET. This guide body 50 is attached to the upper round blade 20
The distance L2 was set to 2 mm from the blade body 25 and the pressing force P was set to 3 mN. In addition, the thickness of the web 12 is 80μ.
m, the width of the web 12 was 1340 mm, the width of the cut-off ear portion was 20 mm, and the web feed speed was 40 m / min.

As Comparative Example 1, as shown in FIG. 7A, the length L3 of the web pressing guide surface 62a in the web width direction is 10 mm, and the rest is the curved guide surface 6.
A web guide 65 designated as 2b was used. The expansion height H1 of the curved guide surface 62b is 5 mm. Other conditions were the same as those in the example, and a cut was made from the side edge 12c of the web 12 to perform edge cutting.

As Comparative Example 2, as shown in FIG. 7B, a web guide having the same shape as that of Comparative Example 1 except that the bulge of the curved guide surface 62b of FIG. It was set to 66. In addition, the other conditions were the same as those in the example, and trimming was performed.

As Comparative Example 3, the edge cutting was performed under the same conditions as in the Example except that the web pressing guide was not used.

In the example, the cut was performed smoothly without the occurrence of wrinkles. In addition, the transport speed is 40 m / min
Even if it was raised, the cut was done smoothly without wrinkles. On the other hand, in Comparative Examples 1 and 2, since the length L2 of the web pressing guide surface 62a was short, slack was generated in the web 12 at the time of cutting, and wrinkles were generated. Further, in Comparative Example 2, the side edge 12 of the web 12 is formed at the connecting portion between the recess 62c and the web pressing guide surface 62a.
c was caught, and similarly, sagging and wrinkling occurred. In Comparative Example 3, wrinkles were generated at the time of cutting, cutting was impossible, and the web 12 was cut.

The curl amount is 20 mm, the web thickness is 40 μm, the flexural modulus is 4000 MPa, and the Young's modulus is 2
For a web of 500 MPa, in this example,
It was possible to cut at a conveying speed of 120 m / min. On the other hand, in Comparative Examples 1, 2, and 3, the base cutting was performed under the same conditions.

[0030]

According to the present invention, the upper round blade or the lower round blade is provided at a position facing the peripheral surface on the web side,
Since a web guide for guiding the web to the cutting position by the upper round blade and the lower round blade and a biasing means for biasing the web guide to the circumferential surface on the web side are provided, a wrinkle is generated. You can smoothly make a notch in the web. As a result, the ears do not break due to the wrinkles and are not cut, and the web can be efficiently manufactured.

The web guide is provided with a guide surface for guiding the side edge of the web, and the guide surface is constituted by an expanding guide surface and a web pressing guide surface to smoothly guide the web to the cutting position. You can Further, the expanding guide surface is formed of a bulging curved surface and the web pressing guide surface is formed of a flat surface, so that the web can be guided more smoothly. Further, by setting the length of the web pressing guide surface in the width direction of the web to be 15 mm or more, the web can be reliably pressed and guided to the cutting position, without causing slack in the ears, The occurrence of wrinkles is effectively suppressed. Further, by configuring the web guide with a friction coefficient of 0.13 or less, the web can be smoothly guided to the cutting position. By urging the web guide at 1 to 50 mN, the web can be reliably guided to the cutting position while suppressing the occurrence of wrinkles without pressing the web too much.

[Brief description of drawings]

FIG. 1 is a plan view showing the outline of a web edge cutting device that implements a web cutting device of the present invention.

FIG. 2 is a side view of the shear blade with the web guide set in a retracted position.

FIG. 3 is a front view of the shear blade with a web guide set in a retracted position.

FIG. 4 is an enlarged front view showing a positional relationship between a web guide, an upper round blade, and a lower round blade.

FIG. 5 is a front view of the shear blade with the web guide set in the guide position.

FIG. 6 is a front view of the shear blade with a web guide set in a guide position.

FIG. 7 is a front view showing a shape of a guide surface of a web guide in an example and a comparative example.

[Explanation of symbols]

10 Web edge cutting device 11 Film forming line 12 Web 12a Both ears 12b knurling 12c side edge 13 shear blades 14 shift part 15 Knurling device 20 Upper round blade 21 Lower round blade 22 Web guide 25 blade body 41 Guide surface 50 Guide body 55 guideway 55a Expansion guide surface 55b Web holding guide surface

Claims (8)

[Claims] 1. A web cutting device for moving a cutter provided with an upper round blade and a lower round blade from a side edge of a feeding web toward a center of the web to cut the web and cutting the web in a feeding direction. In the above, the upper round blade or the lower round blade is provided at a position facing the peripheral surface on the web side, and a web guide for guiding the web to a cutting position by the upper round blade and the lower round blade, and this web. A web cutting device, comprising: a biasing unit that biases the guide to the circumferential surface on the web side. 2. The web guide is provided with a guide surface for guiding the side edge of the web, and the guide surface is composed of a spreading guide surface and a web pressing guide surface. The described web cutting device. 3. The web cutting device according to claim 2, wherein the expanding guide surface is formed of a bulging curved surface, and the web pressing guide surface is formed of a flat surface. 4. The web cutting device according to claim 3, wherein the length of the web pressing guide surface in the width direction of the web is 15 mm or more. 5. The friction coefficient of the web guide is 0.13.
The web cutting device according to any one of claims 1 to 4, wherein the web cutting device comprises the following. 6. The urging means includes one to one of the web guides.
6. A biasing force of 50 mN is set, as in claim 1.
The web cutting device according to claim 1. 7. A web cutting method for moving a cutter comprising an upper round blade and a lower round blade from a side edge of a feeding web toward a center of the web to cut the web, and cutting the web in a feeding direction. The upper and lower round blades are provided with a web guide provided at a position facing the peripheral surface on the web side, and the web side edge at the time of cutting is cut by the upper round blade and the lower round blade. A method for cutting a web, characterized by guiding to. 8. The web has a curl amount of ± 20 mm or less, a base thickness of 20 to 150 μm, and a bending elastic modulus of 39.
00-5100MPa, Young's modulus 2200-2900M
8. The web cutting method according to claim 7, wherein the feeding speed is Pa and the feeding speed is 20 to 120 m / min.