JP6322591B2 - Film edge cutting method, film edge cutting apparatus, and optical film manufacturing method - Google Patents

Description

  The present invention relates to a film edge cutting method, a film edge cutting apparatus, and a method for manufacturing an optical film, and in particular, a film edge cutting method, a film edge, in which the edge of a cut film becomes a strip-shaped ear dust. The present invention relates to a part cutting device and a method for producing an optical film.

  In recent years, thin transparent plastic films have been increasingly used as optical materials such as protective films for polarizing plates of liquid crystal displays and optical compensation films such as retardation plates. The raw materials for these films include cellulose esters, norbornene resins, acrylic resins, polyarylate resins, polycarbonate resins and the like, but cellulose esters are mainly used from the viewpoint of productivity and material prices. In particular, a film of cellulose triacetate (TAC) is particularly advantageously used for optical applications because it has extremely high transparency, low optical anisotropy, and low retardation.

  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. In the production of such a film, the end of the film tends to fluctuate greatly due to uneven drying during drying or neck-in at the time of casting, so that curl or slack occurs at the end of the film. As a result, wrinkles are generated from the end of the film during conveyance, and stable film production cannot be performed. As a countermeasure, a cutting device for cutting and removing the edge of the film in the film transport direction is usually provided in the middle of the film production and winding. Thereby, the width of the film as a product is accurately managed and maintained.

  This cutting device has a shear blade with a round blade, and cuts the end of the film by moving the shear blade from the side edge of the film toward the center of the film while feeding the film and cutting it into the film. . The edge part of the cut film is sent to a recovery part by an air feeding device, recovered, and reused as a raw material.

  As a method for cutting and collecting the cut end of the film, for example, the following Patent Document 1 describes a method in which the cut end of the film is cut into a strip shape and blown to a silo. In Patent Document 2, when the end of the cut film is recovered from the suction port, the transport air supply speed is set to the film transport speed from the upstream side and the downstream side in the film transport direction toward the suction port opening. A film production method is described that supplies a conveying air that is 1 to 60 times and the upstream / downstream speed ratio is less than 1.

  Further, in Patent Document 3, in the process of inserting the cut end film into the pipe and transporting it by air sending, the wind speed in the pipe used for air sending becomes faster from upstream to downstream (wind passing area). Describes an optical film manufacturing method).

JP 2003-291091 A JP 2010-46932 A Japanese Patent No. 5522164

  In recent years, thin films have been demanded for mobile phones and notebook computers. By reducing the film thickness, the end of the cut film is not smoothly conveyed, and the end of the cut film can easily enter the gap between the blades of the cutting device (rotary cutter). There was a problem that the end of the was not cut. In particular, since the edge of the cut film is connected to the film as a product until the first cutting apparatus, if the cutting with the cutting apparatus is not performed smoothly, tension is applied to the cut film end. It was generated and affected even the film that became the product.

  In the ear waste blowing device described in Patent Document 1, the structure from cutting the ear portion to cutting the ear portion into a strip shape is not particularly described. There is a problem that the ear part is broken and the air feeding path is clogged by contacting with the wall surface. For Cited Document 2, by supplying the conveyance air, the film end cut by the conveyance air comes into contact with the suction port, the film end is broken, and the film end is wound around the conveyance roller immediately before the suction port. There was a problem. Moreover, about patent document 3, since the shape of a ventilation pipe is made into a taper shape, a large space is required, and since the shape of a ventilation pipe is changed, only one condition can be made. There was no compatibility and versatility for films of multiple varieties.

  The present invention has been made in view of such circumstances, and a film end cutting method capable of smoothly conveying a film end cut from a film as a product and suppressing an impact caused by cutting the film end. An object of the present invention is to provide a film edge cutting device and a method for producing an optical film.

  In order to achieve the above-mentioned object, the present invention provides a film transporting step in which a film end cut along a film transport direction from a continuously transported film passes through an air feeding pipe and is transported by wind, and a film end. A cutting step of cutting the portion with a rotary cutter comprising a fixed blade and a rotary blade, and the air-feeding pipe has an air suction port, and generates a wind in a direction in which the film end is pressed against the fixed blade Provide edge cutting method.

  According to the present invention, the air blower pipe has an air suction port, and the film is cut by sucking air from the suction port in the transport step of transporting the film end through the air blow pipe. The end can be pressed against the fixed blade. Therefore, when the film end is cut with a rotary cutter, the rotary blade can be applied to the film end at a desired angle, and the film end can be cut stably. In addition, by stably cutting the edge of the film, it is possible to prevent the impact when cutting the edge of the film from being transmitted to the film that will be the product, thus preventing the occurrence of product failure. it can.

  In another aspect of the present invention, the conveyance by wind is preferably performed by suction from the exhaust side.

  According to this aspect, by carrying the film edge by sucking from the exhaust side, it is possible to suck wind from the suction port and blow the wind toward the film edge. Therefore, the film end can be pressed against the fixed blade.

  In another aspect of the present invention, the film thickness is preferably 8 μm or more.

  This aspect defines the film thickness of the film to be cut, and according to the film edge cutting method of the present invention, the film edge can be pressed against the fixed blade, and the rotary blade is against the film edge. Can be brought into contact with each other at a predetermined angle. Therefore, even a thin film can be cut stably.

  In another aspect of the present invention, in the cutting step, the inclination of the film end with respect to the fixed blade is preferably in the range of 0 ° to 25 °.

  According to this aspect, by making the inclination of the film end with respect to the fixed blade within the above range, the film end can be stably cut by being in contact with the rotary blade.

  In another aspect of the present invention, it is preferable to provide a shutter that can be opened and closed at the suction port.

  According to this aspect, by providing the suction port with the shutter, the force for pressing the film end against the fixed blade can be adjusted by opening and closing the shutter.

  In another aspect of the present invention, the air feeding pipe is provided so that the film end portion is conveyed vertically downward, and the suction port of the air feeding pipe is in the conveyance direction of the film end portion. It is preferable that the lowermost part of the suction port is provided immediately before the rotary cutter on the downstream side.

  According to this aspect, the distance between the suction port and the fixed blade can be shortened by providing the suction port immediately before the rotary cutter on the downstream side of the air feeding pipe with respect to the transport direction of the film end. The film edge can be pressed against the fixed blade with air taken in from the suction port.

  In order to achieve the above object, the present invention includes a manufacturing process for manufacturing a film, a film cutting process for cutting a width direction end portion of the film along the film transport direction, and an end portion of the film. 6. An optical film manufacturing method comprising: an edge cutting step of cutting by the film edge cutting method according to any one of 6.

  According to the present invention, the film edge can be stably cut and the cutting impact can be reduced. Therefore, when the film edge is cut, the optical film can be manufactured without affecting the product film. And a good optical film can be produced.

  In order to achieve the above-mentioned object, the present invention achieves the above-mentioned object by supplying air blowing means for blowing the film edge cut along the film conveyance direction by wind from the continuously conveyed film, and a fixed blade for cutting the film edge and rotation. A cutting section having a rotary cutter comprising a blade, and an air feeding pipe that conveys the film end portion to the cutting section, and the air feeding pipe sandwiches the film end portion to be conveyed with air on the opposite side of the fixed blade. A film edge cutting apparatus having a suction port is provided.

  According to the present invention, since the air suction pipe has the air suction port on the opposite side of the fixed blade across the film end to be conveyed, the film end cut by sucking air from this suction port The part can be pressed against the fixed blade. Therefore, when the film end is cut with a rotary cutter, the rotary blade can be applied to the film end at a desired angle, and the film end can be cut stably. In addition, by stably cutting the edge of the film, it is possible to prevent the impact when cutting the edge of the film from being transmitted to the film that will be the product, thus preventing the occurrence of product failure. it can.

  In another aspect of the present invention, the air blowing means is preferably a means for sucking from the exhaust side.

  According to this aspect, by setting the air blowing means for blowing the film end to the suction means for sucking from the exhaust side, it is possible to suck the wind from the suction port and blow the wind toward the film end. Since the fixed blade is provided on the opposite side to the film end of the suction port, the film end can be pressed against the fixed blade.

  In another aspect of the present invention, the suction port is provided at a connection position with the cutting section of the air supply pipe, and the rotary cutter is provided at the entrance of the cutting section where the film end is conveyed from the air supply pipe. It is preferable that

  According to this aspect, the distance between the suction port and the fixed blade of the rotary cutter can be shortened by providing the suction port at the connection position with the cutting part of the air pipe and providing the rotary cutter at the inlet of the cutting part. The air taken in from the suction port can easily press the film end against the fixed blade.

  According to the film edge cutting method, the film edge cutting device, and the optical film manufacturing method of the present invention, by providing a wind intake in the direction of pressing the film edge to be cut on the fixed blade of the rotary cutter. The film can be cut with a rotary cutter, and the impact of cutting the film end can be minimized.

It is the schematic of the manufacturing apparatus of an optical film provided with a film edge part cutting device. It is a perspective view of a film edge part cutting device. It is a figure explaining the effect of a suction mouth.

  Hereinafter, a film end part cutting method, a film end part cutting device, and a method for producing an optical film according to the present invention will be described with reference to the accompanying drawings. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

[Optical film manufacturing equipment]
FIG. 1 is a schematic view showing a part of an optical film manufacturing apparatus provided with the film edge cutting apparatus of the present invention. As shown in FIG. 1, a film 12 continuously conveyed from a film forming line 11 including a film forming machine, a tenter, and a dryer is wound into a roll by a film winding device 14 through a cutting device 13. The cutting device 13 includes a cutter 15 composed of an upper round blade 15 a and a lower round blade 15 b, and the end of the film 12 is cut by the cutter 15. In FIG. 1, the cutting device 13 is described as a configuration including a cutter composed of an upper round blade 15a and a lower round blade 15b. However, the present invention is not limited to this, and a round blade having one round blade and the other groove. It can also be set as the cutter which has the provided shear blade. The film 12 from which the film end portion 12a has been cut is wound into a roll by the film winding device 14. The film end 12a cut from the film 12 by the cutting device 13 is cut into strips by the film end cutting device 30, and further crushed into small pieces by an unshown crusher to be reused.

  Guide rollers 41 and 42 are disposed between the cutting device 13 and the film edge cutting device 30, and the film edge portion 12 a is guided by the guide rollers 41 and 42 and conveyed to the film edge cutting device 30. Is done. The film edge part cutting device 30 conveys the film edge part 12a by suction-pressure feeding by the cut blower 43 provided on the exhaust side.

[Film edge cutting device]
FIG. 2 is a perspective view of the film edge cutting apparatus 30. The film end cutting device 30 cuts the film feeding end 31a which is a pipe for carrying the film end 12a conveyed by the guide rollers 41 and 42 by wind, and the film end 12a which is conveyed through the blowing feeding line 31. The cutting part 33 which has the rotary cutter 32 which consists of the fixed blade 32a and the rotary blade 32b to perform, and the cut blower 43 used as the ventilation means which blows with a wind by attracting | sucking from the exhaust side of the cutting part 33 are comprised.

  The film end portion 12 a guided and conveyed by the guide rollers 41 and 42 passes through the air supply pipe 31 and is conveyed to the cutting portion 33. The cutting part 33 has a fixed blade 32a and a rotary blade 32b. When the rotary blade 32b rotates, the film end 12a is cut into a strip shape between the fixed blade 32a and a strip-shaped film end part. 12b.

  The strip-shaped film end 12b is sent to the cut blower 43, and is further cut into a film end piece. The film end piece cut by the cut blower 43 is conveyed to a collection unit (not shown). In the collection unit, the film is separated into a film end piece and air by a separator composed of a cyclone. The separated film end pieces are sent to a crusher and crushed. Further, the separated air is used for air feeding of the film end 12a. The film end crushed product crushed by the crusher is blown to a silo, and the film end crushed product stored in the silo is reused as a film forming raw material.

  As shown in FIG. 2, the air feeding pipe 31 has an air suction port 34. The air suction port 34 is provided at a position opposite to the fixed blade 32 a provided in the cutting portion 33 with the film end 12 a interposed therebetween. The film end 12 a is sucked and conveyed by the cut blower 43. Therefore, air can be taken in from the suction port 34 by providing the suction port 34. Further, by providing the suction port 34 on the opposite side of the film end 12a with respect to the fixed blade 32a, the film end 12a can be pressed against the fixed blade 32a by the air taken in from the suction port 34. By pressing the film end 12a against the fixed blade 32a, the film end 12a can be stably cut by the rotary blade 32b.

  The inclination of the film end 12a to be conveyed with respect to the fixed blade 32a is ideally 0 °, and the upper limit is preferably 25 ° or less, more preferably 10 ° or less. By setting the inclination of the fixed blade 32a and the film end 12a within the above range, the film end 12a can be pressed against the fixed blade 32a by the rotation of the rotary blade 32b, and the cutting of the film end 12a can be stably performed. It can be carried out. In addition, "the inclination of the film edge part 12a conveyed with respect to the fixed blade 32a" means the angle of the film end part 12a with respect to the straight line of the fixed blade edge | tip of the film edge part side of the fixed blade 32a.

  FIG. 3 is a diagram for explaining the effect of the suction port 34. The film end 12a indicated by the solid line draws air from the suction port 34, whereby the film end 12a can be pressed against the fixed blade 32a, and the film end can be effectively cut by the rotary blade 32b. A film end portion 12a indicated by a two-dot chain line indicates a conveyance state when air is not taken in. When no suction port is provided and no air is taken in, the film end 12a flutters in the conveyance of the film end 12a, and the position of the film end 12a conveyed between the fixed blade 32a and the rotary blade 32b is stable. do not do. If the film edge is transported without providing a suction port, the angle between the fixed blade 32a and the film edge 12a is not stable in the range of 30 to 60 °, and the film edge 12a can be cut depending on the angle. First, when a force is applied to the film end 12a, a film such as a wrinkle may be damaged. By providing the suction port 34, the film end portion 12a can be stably cut.

  In the present embodiment, the cut blower 43 sucks air from the exhaust side of the cutting part 33, thereby taking in air from the suction port 34 and pressing the film end 12a against the fixed blade 32a. Thereby, the film edge part 12a can be cut stably. When air is pushed into or blown into the suction port 34, air may flow backward to the inlet side of the film end 12 a of the air sending pipe 31, and the conveyance of the film end 12 a may become unstable. is there. If the conveyance of the film end portion 12a becomes unstable, the angle between the fixed blade 32a and the film end portion 12a increases, which is not preferable because a cutting failure occurs.

  The position where the suction port 34 is provided is preferably provided on the downstream side in the transport direction of the film end portion 12a of the air feeding pipe 31, that is, on the cutting portion 33 side. By providing the suction port 34 on the downstream side in the transport direction of the film end 12a, the film end 12a can be easily pressed against the fixed blade 32a. In particular, as shown in FIGS. 2 and 3, the air supply pipe 31 is formed in the vertical direction, the suction port 34 is provided at the joining position of the cutting part 33 and the air supply pipe 31, and the rotary cutter 32 is connected to the entrance of the cutting part 33. By providing in, the lowest part of the suction port 34 can be provided in front of the rotary cutter 32. By providing the suction port 34 immediately in front of the rotary cutter 32, the film end 12a can be easily pressed against the fixed blade 32a by the air taken in from the suction port 32. If the distance from the suction port 34 to the cutting portion 33 is long, the film end 12a may flutter between the suction port 34 and the cutting portion 33, and may not be stably cut. “The lowest part of the suction port is provided immediately before the rotary cutter” means that the distance between the lowest part of the suction port and the rotary cutter (cutting point) is 200 mm or less in the transport direction of the film end. That means.

  The suction port 34 is preferably provided with a shutter 35 that can be opened and closed. By providing the shutter 35, it is possible to adjust the amount of air that enters the air feeding pipe 31, and it is possible to press the film end 12 a with an appropriate amount of air.

  In the present invention, air is sucked so as to press the film end 12a against the fixed blade 32a and is cut by the rotary blade 32b. Therefore, the film end 12a to be conveyed is between the fixed blade 32a and the rotary blade 32b. Can be prevented from entering. Therefore, even a thin film can be cut stably. Although it does not specifically limit as a film thickness of a film, It can carry out with respect to the film of a film thickness of 8 micrometers or more. Although the upper limit of a film thickness is not specifically limited, It can use especially effectively with respect to a film of 40 micrometers or less.

[Optical film manufacturing method, film edge cutting method]
Next, an optical film manufacturing apparatus, an optical film manufacturing method using the film edge cutting apparatus, and a film edge cutting method will be described.

≪Manufacturing process≫
A manufacturing process is a process of manufacturing the film 12 with the film forming line 11 shown in FIG. The film forming line 11 includes a film forming machine, a tenter, and a dryer, and can form a film by a known method.

≪Film cutting process≫
The film cutting step is a step of cutting the width direction end of the film 12 manufactured and continuously conveyed by the cutting device 13 along the film conveyance direction. By cutting the end portion of the film formed by the manufacturing process, it is possible to cut the film end portion where unevenness of thickness and wrinkle are easily generated, and the width of the film as a product can be managed.

≪End cutting process (film edge cutting method) ≫
<Conveying process>
The film edge part cut | disconnected by the film cutting process passes the ventilation pipe 31, and is conveyed to a cutting part. The air supply pipe 31 is provided with an air suction port 34, and by taking air from the suction port 34, the film end 12 a is pressed against the side opposite to the position where the suction port 34 is provided. In the present invention, since the suction port 34 is provided on the side opposite to the fixed blade 32a provided in the cutting portion 33 and the film end 12a, the film end 12a can be pressed against the fixed blade 32a.

<Cutting process>
The cutting step is a step of cutting the film end 12a with the fixed blade 32a and the rotary blade 32b of the rotary cutter 32. Since the film end 12a is pressed against the fixed blade 32a and conveyed by the conveying step, the film end 12a can be stably cut by the rotary blade 32b. By stably cutting the film end 12a, it is possible to prevent the occurrence of failure such as wrinkles in the film as a product. In addition, since it is possible to prevent the film edge from being broken, it is possible to stably carry the film edge, and continuously, without stopping the production of the film due to poor conveyance of the film edge. Film production can be performed.

  Hereinafter, the present invention will be described in more detail with reference to examples.

  The film edge cutting apparatus is arranged as shown in FIG. 2 and has a suction port and a shutter at a position where air is taken in the direction in which the film edge is pressed against the fixed blade of the rotary cutter (described as “fixed blade” in Table 1). Arranged. Further, as a comparative example, a suction port and a shutter were installed in a direction separating the film edge from the fixed blade (position on the fixed blade side of the air-feeding pipe, described as “anti-fixed blade” in Table 1). Moreover, it carried out also when the suction port was not provided (described as “no suction port” in Table 1).

  Cutting was performed using films having different thicknesses without changing the clearance of the cutter of the rotary cutter. The evaluation evaluated whether or not the edge of the film to be continuously fed could be cut and whether there was a cutting impact enough to tear the film edge.

Whether or not cutting is possible was evaluated according to the following criteria.
A: The film edge can be continuously cut, and the cut strip-like film edge is continuously discharged.
B: The film edge is not continuously cut.

Further, the cutting impact was evaluated according to the following criteria.
A: No tension fluctuation.
B: Fluctuates as the film end is pulled or the film end is shredded when the film end is cut.

  In the evaluation, regardless of the thickness of the film, whether the cutting is possible and the cutting impact are both “A” are evaluated as “A”, and the evaluation of “B” is any of the cutting availability and the cutting impact. Some were designated “B”. An example in which the direction of the suction port is arranged in the direction of pressing the film end against the fixed blade is an example of the present invention. The results are shown in Table 1.

  As shown in Table 1, when the position of the suction port is provided on the fixed blade side of the air supply pipe and the film end is cut so as to press the opposite side of the fixed blade, as shown by the two-dot chain line in FIG. The angle between the fixed blade and the transported film end was increased, and the film end could not be cut. In particular, when the film thickness was reduced, it became easier to enter the clearance between the fixed blade and the rotary blade, and could not be cut with a rotary cutter. In addition, since it is easy to enter the clearance between the fixed blade and the rotary blade, the cutting cannot be performed stably, and the cutting impact is large.

  Even when the suction port is not provided, the film flutters and the film edge cannot be stably conveyed to the cutting part, and when the film thickness is thin, the film can be stably cut. Moreover, the cutting impact was great.

  In the example in which the suction port was provided so as to press the end of the film against the fixed blade, it was possible to stably perform the cutting process even on a thin film, and no cutting impact was observed.

  DESCRIPTION OF SYMBOLS 11 ... Film-forming line, 12 ... Film, 12a ... Film edge part, 12b ... Strip-shaped film edge part, 13 ... Cutting device, 14 ... Film winding device, 15 ... Cutter, 30 ... Film edge part cutting device, 31 ... Air supply piping, 32 ... Rotary cutter, 32a ... Fixed blade, 32b ... Rotary blade, 33 ... Cutting part, 34 ... Suction port, 35 ... Shutter, 43 ... Cut blower

Claims (8)

From the continuously transported film, the film end cut along the transport direction of the film, passing through the air pipe, transported by wind,
A cutting part is provided on the downstream side of the air feeding pipe with respect to the conveying direction of the film end, and the cutting part includes a rotary cutter composed of a fixed blade and a rotary blade , and the film end is a rotary cutter . A cutting process for cutting,
The air pipe has a suction port on the opposite side of the fixed blade across the film end to be conveyed ,
The transporting step transports the film end by sucking from the exhaust side provided downstream of the cutting portion with respect to the transport direction of the film end, and from the suction port, A film end cutting method in which air is sucked into a feed pipe and into the cutting section to generate wind in a direction in which the film end is pressed against the fixed blade. The film end cutting method according to claim 1 , wherein the film has a thickness of 8 μm or more. The film edge part cutting method according to claim 1 or 2 , further comprising a shutter that can be opened and closed at the suction port. The film end cutting method according to claim 3, wherein in the cutting step, the inclination of the film end with respect to the fixed blade is in a range of 0 ° to 25 °. The air pipe is provided so that the film end is conveyed downward in the vertical direction,
The suction port, the conveying direction of the film end, a downstream side of the air feed pipe, the bottom of said suction port, said claims 1 provided just before the rotary cutter 4 The film edge part cutting method of any one of Claims 1. A manufacturing process for manufacturing a film;
A film cutting step for cutting the widthwise end of the film along the film conveyance direction;
The edge part cutting process of cutting the edge part of the said film with the film edge part cutting method of any one of Claim 1 to 5. The manufacturing method of the optical film which has. Blowing means for blowing air by wind on the film edge cut along the film conveyance direction from the continuously conveyed film,
A cutting part having a rotary cutter consisting of a fixed blade and a rotary blade for cutting the film end; and
An air supply pipe that is provided on the upstream side of the cutting portion with respect to the conveyance direction of the film end portion and conveys the film end portion to the cutting portion;
The wind sending pipe, across the film end to be conveyed, the air transmission and distribution pipe on opposite sides of the fixed blade, and the cutting portion, have a suction port for sucking air,
The said air blow means is a film edge part cutting device which is a means to attract | suck from the exhaust side downstream of the said cutting part with respect to the conveyance direction of the said film edge part. The suction port is provided at a connection position with the cutting part of the air pipe,
The said rotary cutter is a film edge part cutting apparatus of Claim 7 provided in the entrance of the said cutting part to which the said film edge part is conveyed from the said air supply piping.

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