JP5776146B2 - Film cutting method and film cutting apparatus - Google Patents

Description

  The present invention relates to a technique for cutting a resin film.

  In recent years, various films, such as a base film of a polarizing plate, a polarizing element film, and a transparent protective film for protecting the polarizing element film, are disposed in an image display region of a liquid crystal display device. As such a film, for example, a resin film having excellent translucency such as a cellulose ester resin film is used.

  Such a resin film is formed by casting a resin solution (dope) onto the surface of an endless belt, drying it while transporting it to form a cast film, peeling it off from the endless belt, stretching and drying it, It is cut and finally wound up by a winding roller.

  If the residual solvent amount or the film thickness deviation in the width direction of the resin film is large, the tension of the resin film varies in the width direction, and intermittent wrinkles and meandering occur in the resin film. Thereby, in the cutting process which cuts the edge part of a resin film continuously in a conveyance direction, there exists a problem that the slit cut defect that a resin film fractures | ruptures generate | occur | produces.

  In Patent Document 1, a tenter drying process for drying while stretching a film using a tenter clip is performed to prevent breakage of the film that occurs when the film edge is cut by a crease generated on the edge of the film. The following technique is disclosed for the purpose. That is, it is disclosed that in the tenter drying step, the solvent content of the film ear portion outside the biting portion of the film by the tenter clip is 17% by weight or less.

  Patent Document 2 discloses a technique for cutting a thin web without generating wrinkles. When cutting the web 12 using the upper round blade 20 and the lower round blade 21, the lower round blade 21 is cut. A guide body 50 that presses the web 12 on a guide surface 42 provided on is provided.

  Patent Document 3 discloses a suction roller that supplies negative pressure to a sealed space 12 inside a suction roll outer cylinder 11 and sucks and conveys a resin film to a plurality of mounting ports 14 provided on the outer periphery of the suction roll outer cylinder 11. Is disclosed.

JP 2003-266457 A JP 2003-291090 A JP 2004-99190 A

  However, in Patent Document 1, in the tenter drying process, wrinkles of the film are prevented by adjusting the solvent content of the film ears, but at high speed stretching or large stretching ratio, deformation around the clip gripping part, Wrinkles occur and slit cut defects occur during cutting.

  Further, in Patent Document 2, since a guide main body 50 for pressing the film is separately provided, the film pressing guide is in contact with the film, so that the generation of scratches and accompanying generation of the guide or film powder, This powder adheres to the film and causes foreign matter. In addition, when the scratch is severe, there is a problem that the film is resisted and cut.

  Moreover, in patent document 3, the curling of an edge part cannot be contacted by the both-ends edge diameter reduction roll, the deformation | transformation which generate | occur | produces in a tenter clip holding part cannot be absorbed, the film conveyance state in a cutting part is not stable, and a cutting defect is caused. It will occur.

  The objective of this invention is providing the film cutting apparatus and film cutting method which can prevent the slit cut defect which arises when cutting the edge part of a resin film continuously in a conveyance direction.

(1) A film cutting method according to an aspect of the present invention is a film cutting method for cutting a resin film using a film cutting device, wherein the film cutting device is formed by forming a groove on the surface. A cylindrical rotating body that includes one blade and conveys a resin film, and a disk-shaped disk that is rotatably arranged and is cut in the conveying direction by sandwiching the resin film conveyed by the rotating body with the first blade. The groove portion is provided on at least one end surface side of the rotating body, and the rotating body is provided on the other end surface side of the groove portion, and on the other side of the groove portion, the one side a suction roller having an end portion provided at an end face, in the body portion, closer to the groove, the suction hole to the area suction hole is not formed to form a Suction holes are arranged so the proportion of the region increases.

A film cutting device according to another aspect of the present invention is a film cutting device for cutting a resin film, and includes a first blade formed by forming a groove on the surface, and a cylinder that conveys the resin film And a disk-shaped second blade that is disposed rotatably and that is cut in the conveying direction by sandwiching a resin film conveyed by the rotating body with the first blade, and the groove portion The rotating body is provided on at least one end face side of the rotating body , and the rotating body includes a main body part provided on the other end face side from the groove part and an end part provided on the one end face side from the groove part. comprising a suction roller, in the body portion, the closer to the groove, illusion as proportion of the suction hole to the area suction hole is not formed is formed region increases Down hole is arranged.

According to this structure, the edge part of the film conveyed by a rotary body is continuously cut | judged in a conveyance direction because a 2nd blade and a 1st blade pinch | interpose while rotating a resin film. Here, the rotating body is constituted by a suction roller. Therefore, the resin film conveyed by the rotator is drawn by being attracted and adhered by the negative pressure generated from the rotator, and wrinkles and the like are removed. As a result, even a resin film having a large amount of residual solvent and large film thickness deviation can be cut without causing a slit cut defect such as breaking the resin film.
When the number and area of the suction holes are increased, the negative pressure applied to the resin film increases, so from the viewpoint of suppressing wrinkles and the like, it is preferable to increase the number and area of the suction holes. However, since the suction hole may leave a hole mark on the resin film, it is not preferable to provide the suction hole excessively. On the other hand, from the standpoint of preventing slit cut defects, it is sufficient that a suction hole is provided only in the vicinity of the cutting position.
Therefore, a configuration is adopted in which the suction holes are arranged so that the ratio of the area where the suction holes are formed to the area where the suction holes are not formed increases as approaching at least one end of the rotating body. Thereby, while suppressing a hole trace, the slit cut defect can be prevented.
Further, according to this configuration, the groove portion is provided on the end portion side of the rotating body, and as the rotating body approaches the groove portion, the ratio of the region where the suction hole is formed to the region where the suction hole is not formed increases. Suction holes are arranged as shown. Therefore, a negative pressure can be applied to a region that is not preferable when wrinkles or the like are generated, and the negative pressure can be efficiently applied to the resin film.

  (2) In the film cutting method, it is preferable to cut a resin film having a film thickness deviation of 3 or more or a residual solvent amount of 30% or less.

  When the film thickness deviation is 3 or more, the resin film has a large variation in tension in the width direction, and thus intermittent wrinkles and meandering are likely to occur, and slit cut defects are likely to occur. However, according to this configuration, the resin film is sucked and adhered by the negative pressure from the rotating body, and wrinkles and the like are removed. Therefore, it is possible to cut the resin film while preventing the slit cut failure.

  In addition, since a wrinkle etc. of a resin film will decrease, so that a film thickness deviation is small, the one where a film thickness deviation is small is preferable from a viewpoint of preventing a slit cut defect. On the other hand, there is a certain limit in reducing the film thickness deviation in the resin film manufacturing process. From these viewpoints, the film thickness deviation is preferably 2 μm or less, more preferably 1 μm or less.

  The residual solvent amount is represented by the residual solvent amount (%) = ((MN) / N) × 100, where M is the mass of the resin film at a certain point and N is the mass of the dried resin film. The That is, the larger the residual solvent amount, the higher the viscosity of the resin film and the easier the wrinkles. In addition, as a dried resin film, the resin film when dried at 110 degree | times for 3 hours is employable, for example.

  Therefore, there is a certain limit in removing wrinkles by stretching the resin film by the negative pressure generated from the rotating body. This limit is defined as 30%, which is the upper limit of the numerical range of the residual solvent amount. In the configuration of (2), the cutting process is applied to a resin film having a residual solvent amount of 30% or less. Therefore, it is possible to prevent the slit cut defect more reliably.

  Thus, since the wrinkles and the like are less likely to occur as the residual solvent amount is smaller, it is preferable to cut a resin film having a small residual solvent amount from the viewpoint of preventing slit cut defects. However, when it does so, the drying time of a resin film will become long and the throughput of manufacture of a resin film will fall. Therefore, there is a certain limit to reducing the amount of residual solvent. From these viewpoints, the amount of residual solvent is preferably 20% or less, more preferably 10 or less.

(3) In the film cutting method, it is preferable that the first blade constitutes a lower blade and the second blade constitutes an upper blade.

  According to this structure, since the 1st blade has comprised the lower blade, the rotary body is located below a 2nd blade with the resin film conveyed with a rotary body. Therefore, a negative pressure is applied to the resin film in the same direction as gravity, and the negative pressure from the rotating body is applied without loss. Therefore, wrinkles and the like generated on the resin film can be more reliably removed.

( 3 ) In the film cutting method, it is preferable that the groove is provided on at least one end side of the rotating body, and the ratio of the rotating body increases toward the groove.

  According to this configuration, the groove is provided on the end side of the rotating body, and as the rotating body approaches the groove, the ratio of the area where the suction holes are formed to the area where the suction holes are not formed increases. Suction holes are arranged. Therefore, a negative pressure can be applied to a region that is not preferable when wrinkles or the like are generated, and the negative pressure can be efficiently applied to the resin film.

( 4 ) In the film cutting method, it is preferable that the rotating body has the suction hole formed within a width of 30% from the groove portion with respect to the entire width of the main body portion.

  According to this configuration, since the suction hole is formed in a region 30% from the end in the entire width of the rotating body, negative pressure can be applied to an unfavorable region when wrinkles or the like are generated. A negative pressure can be efficiently applied to the film.

  ADVANTAGE OF THE INVENTION According to this invention, the slit cut defect which arises when cutting the edge part of a resin film continuously in a conveyance direction can be prevented.

It is the schematic which shows the basic composition of the manufacturing apparatus of the film by embodiment of this invention. It is a partially expanded view for demonstrating the detail of the film cutting apparatus shown in FIG. It is the figure which showed concretely the suction hole provided in the rotary body shown in FIG. It is a figure for demonstrating the malfunction at the time of cutting a film using the rotary body in which the suction hole is not formed in the main-body part. It is the figure which showed another example of the arrangement pattern of a suction hole.

  FIG. 1 is a schematic diagram showing a basic configuration of a film manufacturing apparatus S according to an embodiment of the present invention. The manufacturing apparatus S includes an endless belt portion 11, a casting die 12, a peeling roller 13, a stretching device 14, a film cutting device 15, a drying device 16, an embossing device 17, and a winding device 18.

  The casting die 12 casts a resin solution (dope) DP in which a transparent resin is dissolved onto the surface of the endless belt portion 11. The endless belt portion 11 is formed into a film by forming a web of dope DP cast from the casting die 12 and drying it while being conveyed.

  The peeling roller 13 peels the film from the endless belt portion 11. The stretching device 14 stretches the film in the width direction by pulling both ends in the width direction of the film outward with a clip.

  The film cutting device 15 is a device that continuously cuts the end of the film in the transport direction, and will be described in detail later. The slit roller 191 conveys an end portion (hereinafter referred to as a slit) of the film cut by the film cutting device 15 toward a slit collecting unit (not shown). In addition, the slit accommodated in the slit collection | recovery part is reused as a raw material.

  The transport roller 192 transports the film with the slit cut toward the drying device 16. The drying device 16 dries the film whose end has been cut. The emboss forming device 17 forms an embossed portion at the end of the film dried by the drying device 16. The winding device 18 winds up the film on which the emboss is formed, and uses it as a film roller.

  As shown in FIG. 1, the casting die 12 is supplied with dope DP from a dope supply pipe connected to the upper end of the casting die 12. Then, the supplied dope DP is discharged from the casting die 12 to the endless belt portion 11, and a web is formed on the endless belt portion 11.

  The endless belt portion 11 includes a metal endless belt whose surface travels infinitely with a mirror surface. As the endless belt, for example, a belt made of stainless steel or the like is preferable from the viewpoint of peelability of the film. From the viewpoint of effectively utilizing the width of the endless belt portion 11, the width of the cast film cast by the casting die 12 is preferably 80 to 99% with respect to the width of the endless belt portion 11.

  And in order to finally obtain a film with a width | variety of 1000-4000 mm, it is preferable that the width | variety of the endless belt part 11 is 1800-5000 mm. Further, instead of the endless belt portion 11, a rotating metal drum having a mirror surface may be used.

  And the endless belt part 11 dries the solvent in dope DP, conveying the cast film (web) formed on the surface. This drying is performed by, for example, heating the endless belt portion 11 or blowing heated air on the web. At that time, although the temperature of the web varies depending on the solution of the dope DP, the range of −5 to 70 ° C. is preferable and the range of 0 to 60 ° C. is considered in consideration of the conveyance speed and productivity accompanying the evaporation time of the solvent. Is more preferable.

  The higher the temperature of the web, the faster the solvent can be dried. However, when the temperature is too high, the web tends to foam or the flatness tends to deteriorate.

  When heating the endless belt portion 11, for example, a method of heating the web on the endless belt portion 11 with an infrared heater, a method of heating the back surface of the endless belt portion 11 with an infrared heater, and heating air on the back surface of the endless belt portion 11. The method of spraying and heating etc. is mentioned, What is necessary is just to select suitably as needed.

  In addition, when blowing heated air, the wind pressure of the heated air is preferably 50 to 5000 Pa in consideration of the uniformity of solvent evaporation and the like. The temperature of the heating air may be dried at a constant temperature, or may be supplied in several steps in the running direction of the endless belt portion 11.

  The time between casting the dope DP on the endless belt portion 11 and peeling the web from the endless belt portion 11 varies depending on the film thickness of the film to be produced and the solvent used. In consideration of the peelability from 11, it is preferably in the range of 0.5 to 5 minutes.

  The ratio (draft ratio) of the casting film conveyance speed to the traveling speed of the endless belt portion 11 is preferably about 0.8 to 1.2. When the draft ratio is within this range, the cast film can be stably formed. For example, if the draft ratio is too large, there is a tendency to cause a phenomenon called neck-in in which the cast film is reduced in the width direction, and if so, a wide film cannot be formed.

  The peeling roller 13 is in contact with the surface of the endless belt portion 11 on the side where the dope DP is cast, and peels the dried web (film) by applying pressure to the endless belt portion 11 side. When peeling a film from the endless belt part 11, a film is extended | stretched in the conveyance direction (Machine Direction: MD direction) of a film by peeling tension and subsequent conveyance tension. For this reason, it is preferable that the peeling tension and the conveyance tension when peeling the film from the endless belt portion 11 are 50 to 400 N / m.

  Further, the total residual solvent amount of the film when the film is peeled from the endless belt portion 11 is the peelability from the endless belt portion 11, the residual solvent amount at the time of peeling, the transportability after peeling, and the film formed after transporting and drying Considering physical properties and the like, it is preferably 30 to 200% by mass.

  The stretching device 14 stretches in the width direction by gripping both ends in the direction (width direction) perpendicular to the film transport direction with a clip or the like and increasing the distance between the opposing clips. Here, the extending | stretching apparatus 14 may be provided with the apparatus which cut | disconnects the area | region which was holding the clip.

  The emboss forming device 17 forms an embossed portion on the film during conveyance of the film at at least one end in the width direction of the film. The embossed portion is a belt-like shape having a plurality of convex portions and concave portions.

  The winding device 18 winds the film transported from the embossing device 17 around the core to the required length. The temperature at the time of winding is preferably a temperature of about room temperature in order to prevent scratches, loose winding, and the like due to shrinkage after winding. As a winder to be used, an apparatus for winding a film by a winding method such as a constant tension method, a constant torque method, a taper tension method, or a program tension control method with a constant internal stress may be adopted.

  Moreover, it is preferable that the width | variety of a film is 1000-4000 mm from the point of the use to a large sized liquid crystal display device, the use efficiency of the film at the time of polarizing plate processing, and production efficiency. Moreover, it is preferable that the film thickness of a film is 30-90 micrometers from points, such as a viewpoint of thickness reduction of a liquid crystal display device, and the production stabilization of a film. Here, the film thickness is an average film thickness. For example, the thickness is measured at 20 to 200 locations in the width direction of the film with a contact-type film thickness meter manufactured by Mitutoyo Corporation, and the average value of the measured values. Should be adopted.

  In the present embodiment, the film is a resin film, for example, an optical film attached to a liquid crystal display panel. Hereinafter, the composition of the resin solution used in the present embodiment will be described.

  The transparent resin used in the present embodiment is not particularly limited as long as it is a resin having transparency when formed into a substrate by a solution casting film forming method or the like. It is preferable that the production by the method is easy, the adhesiveness with the hard coat layer and the like is excellent, the optically isotropic property, and the like. Here, the transparency means that the visible light transmittance is 60% or more, preferably 80% or more, and more preferably 90% or more.

  Specific examples of the transparent resin include cellulose ester resins such as cellulose triacetate resin. The dope DP used in the present embodiment may contain fine particles. In this case, the fine particles to be used are appropriately selected according to the purpose of use, but are preferably fine particles that can scatter visible light when contained in a transparent resin.

  The fine particles may be inorganic fine particles such as silicon oxide, or organic fine particles such as acrylic resin. As the solvent used in the present embodiment, a solvent containing a good solvent for the transparent resin can be used, and a poor solvent may be contained as long as the transparent resin does not precipitate.

  Examples of the good solvent for the cellulose ester resin include organic halogen compounds such as methylene chloride. Moreover, as a poor solvent with respect to a cellulose-ester-type resin, C1-C8 alcohols, such as methanol, etc. are mentioned, for example. The resin solution used in the present embodiment may contain other components (additives) other than the transparent resin, fine particles and solvent as long as the effects of the present invention are not impaired. Examples of the additive include a plasticizer, an antioxidant, an ultraviolet absorber, a heat stabilizer, a conductive substance, a flame retardant, a lubricant, and a matting agent.

  Moreover, the solution of a cellulose-ester-type resin is obtained by mixing said each composition. The obtained cellulose ester resin solution is preferably filtered using a suitable filter medium such as filter paper.

  FIG. 2 is a front view for explaining details of the film cutting apparatus 15 shown in FIG. As shown in FIG. 2, the film cutting device 15 includes a cylindrical rotating body 2 and an upper blade portion 3.

  The rotating body 2 has a groove 22 on one end face 23a side. In the rotating body 2, the other end surface 23 b side from the groove portion 22 is described as a main body portion 21, and the end surface 23 a side from the groove portion 22 is described as an end portion 23.

  The side wall on the end face 23 b side of the groove 22 constitutes the lower blade 221. The width Y2 of the end portion 23 in the width direction is significantly smaller than the width Y1 of the main body portion 21 in the width direction, for example, slightly smaller than the length in the width direction of the slit obtained by cutting the film. Set to size. The length Y1 should just have the length of the width direction of the film used as a finished product at least. The length Y3 of the groove part 22 in the width direction may be at least long enough to allow the upper blade 31 constituting the upper blade part 3 to enter. For example, the length Y3 of the upper blade 31 in the width direction is sufficient. A length of about 3 to 10 times the length Y4 can be employed.

  A rotating shaft 24 is attached to the outer side of the end portion 23 in the width direction. The rotating shaft 24 has a long cylindrical shape in the width direction of the rotating body 2 and rotates integrally with the rotating body 2. The motor 25 applies a driving force for rotating the rotating body 2 to the rotating shaft 24. The motor 25 is connected to a control unit (not shown) and is driven according to a control signal output from the control unit. As the motor 25, various motors such as a DC motor, an AC motor, and a stepping motor can be employed.

  The upper blade portion 3 includes an upper blade 31, a holder 32, a rotating shaft 33, and a motor 34. The upper blade 31 is composed of a disk-shaped member made of ceramic or metal, for example. The upper blade 31 is formed with a taper 311 so that the outer peripheral portion becomes thinner in the radial direction, and the entire outer periphery is sharpened. The taper 311 is provided on the opposite side of the lower blade 221.

  Holders 32 for holding the upper blade 31 are attached to both surfaces of the upper blade 31. The holder 32 has a radius smaller than that of the upper blade 31, for example, a disk shape. A rotation shaft 33 is attached to the holder 32. The rotating shaft 33 has a long cylindrical shape in the width direction and rotates integrally with the upper blade 31 and the holder 32. A motor 34 is attached to the rotating shaft 33. The motor 34 applies a driving force for rotating the upper blade 31 to the rotation shaft 33. The motor 34 is connected to a control unit (not shown) and is driven according to a control signal output from the control unit. As the motor 34, various motors such as a DC motor, an AC motor, and a stepping motor can be employed.

  The film is transported in the transport direction by the rotation of the rotating body 2, but the upper blade 31 rotates in the direction of transporting the film and enters the groove portion 22. Therefore, the upper blade 31 and the lower blade 221 act like scissors to cut the film.

  In FIG. 2, the groove 22 is formed only on the end surface 23a side, but may be provided on the end surface 23b side. In this case, the upper blade portion 3 may be provided also in the groove portion on the end face 23b side to form a pair of upper blade portions 3. By carrying out like this, the both ends of the width direction of a film are continuously cut | judged in a conveyance direction.

  In the present embodiment, the rotating body 2 is configured by a suction roller in which a plurality of suction holes are formed on the surface of the main body portion 21. Specifically, a cavity communicating with the suction hole is formed inside the main body 21. A negative pressure generated by a suction device (not shown) is supplied into the cavity. Therefore, when the film is conveyed by the rotating body 2, negative pressure from the suction hole is applied.

  FIG. 3 is a view specifically showing suction holes provided in the rotating body 2 shown in FIG. 2, (A) shows a perspective view of the rotating body 2 that is transporting the film F, and (B) shows The front view of the rotary body 2 is shown, (C) shows the front view of the rotary body 2 which is conveying the film F, (D) is the figure which looked at the film F under cutting from the upper side.

  In FIG. 3A, the film F is conveyed in the direction indicated by K. As shown in FIG. 3A, it can be seen that wrinkles SW are generated on the film F on the upstream side in the transport direction K from the upper blade 31. Wrinkles SW are generated when the film F has a large film thickness deviation and a large amount of residual solvent, resulting in non-uniform tension in the width direction of the film F.

  As shown in FIG. 3B, a plurality of suction holes H are formed on the surface of the main body 21. Therefore, as shown in FIG. 3C, it can be seen that the film F in the region contacting the main body portion 21 is sucked and adhered by applying a negative pressure from the suction hole H, and the wrinkles SW are removed.

  Therefore, even if the slit SL is cut from the film F with the upper blade 31 and the lower blade 221, the slit cut defect that the film F is broken due to the wrinkle SW can be prevented.

  In addition, in the edge part 23 in which the suction hole H is not formed, as shown in FIG.3 (C), it turns out that the negative pressure is not provided to the film F and wrinkles SW remain | survive. Therefore, there is a possibility that a slit cut defect may occur in the slit SL. However, since the slit SL is an unnecessary portion, there is no problem even if a slit cut defect occurs. In order to prevent a slit cut defect in the slit SL, a large number of suction holes H may be provided in the end portion 23 as in the main body portion.

  FIG. 4 is a diagram for explaining a problem when the film F is cut using the rotating body 2 in which the suction hole H is not formed in the main body portion 21. 4A is a perspective view of the rotating body 2 that is transporting the film F, FIG. 4B is a front view of the rotating body 2, and FIG. 4C is a front view of the rotating body 2 that is transporting the film F. (D)-(F) is the figure which looked at the film F under cutting from the upper side.

  In FIG. 4, since the suction hole H is not formed in the rotator 2, no negative pressure is applied to the film F. Therefore, as shown in FIGS. 4C and 4F, it can be seen that the wrinkles SW are not removed from the film F at the time of cutting.

  In FIG. 4 (D), the upper blade 31 and the lower blade 221 cut a portion where the film thickness deviation happens to be small and the wrinkle SW is not generated, so that no slit defect occurs. However, the wrinkle SW shown in FIG. 4E reaches the upper blade 31, and the upper blade 31 and the lower blade 221 eventually cut a portion where the wrinkle SW is generated. At this time, as shown in FIG. 4 (F), the cutting line CL of the film F, which should be parallel to the conveying direction K, is sunk into the center side in the width direction, the film F is broken, and the slit cut defect is caused. You can see that it has occurred.

  In the present embodiment, as shown in FIG. 3B, the ratio of the region where the suction hole H is formed to the region where the suction hole H is not formed as it approaches the suction hole H and the groove 22 (cutting position). Are arranged to increase.

  In the example of FIG. 3B, the area of each suction hole H is the same, but it can be seen that the number of suction holes H increases as it approaches the groove 22. Therefore, a larger negative pressure is applied to the film F as it approaches the groove 22. Therefore, the wrinkle SW can be removed from the film F at the location where the upper blade 31 cuts. This makes it possible to apply a strong negative pressure to the film F only at the location where the wrinkle SW should be removed. As a result, the suction holes H are not excessively provided, and the film F can be prevented from forming hole marks due to the suction holes H, and at the same time, the slit cut defect can be prevented.

  The arrangement pattern of the suction holes H is not limited to that shown in FIGS. 3 (B) and 3 (C). FIG. 5 is a view showing another example of the arrangement pattern of the suction holes H. FIG. In FIG. 5A, the main body 21 is partitioned into five cylindrical regions D1 to D5 at equal intervals from the lower blade 221 toward the center in the width direction.

  In the regions D5 to D3, a small circular suction hole H1 is formed. In the regions D2 to D1, a large circular suction hole H2 having a larger area than the suction hole H1 is formed. Further, the number of the suction holes H1 increases toward the regions D5 to D3, and the number of the suction holes H2 increases toward the regions D2 to D1. Further, the number of suction holes H2 in the region D2 is equal to the number of suction holes H1 in the region D3.

  Therefore, in each of the regions D1 to D5, the ratios R1 to R5 of the regions where the suction holes H are formed with respect to the regions where the suction holes H are not formed increase from the ratio R5 toward the ratio R1. Therefore, the ratio R of the region in which the suction hole H is formed to the region in which the suction hole H is not formed increases as it goes toward the lower blade 221.

  In FIG. 5B, only the suction holes H1 are arranged in the regions D1 to D5, and the number of the suction holes H1 increases from the region D5 toward the region D1. Therefore, the ratio R of the region in which the suction hole H is formed to the region in which the suction hole H is not formed increases as it goes toward the lower blade 221.

  In FIG. 5C, the suction holes H1 are arranged in the regions D3 to D5, and the suction holes H2 and the square-shaped suction holes H3 circumscribing the suction holes H2 are arranged in the region D2. Are arranged with diamond-shaped suction holes H4 having a larger area than the suction holes H3. Further, the number of the suction holes H1 is increased from the region D5 toward the region D3. Further, the number of suction holes H in the region D3 and the region D2 is equal. Therefore, the ratio R of the region in which the suction hole H is formed to the region in which the suction hole H is not formed increases as it goes toward the lower blade 221.

  In any case, in FIGS. 5A to 5C, the proportion R of the region where the suction holes H are formed to the region where the suction holes are not formed increases toward the lower blade 221. I understand that.

  In FIGS. 5A to 5C, the main body 21 is divided into five regions D1 to D5. However, this is only an example, and six, seven, or eight or more regions are included. May be divided into a predetermined number of regions or a predetermined number of regions of 2 or more and 4 or less.

  In the example of FIG. 5A, two types of suction holes H1 and H2 are used as the circular suction holes H. However, this is only an example, and three or more types of circular suction holes H having different areas are used. May be adopted. Specifically, in each region R, the number of suction holes H is the same, but the area of each suction hole H may be gradually increased toward the lower blade 221.

  In addition, in the example of FIG. 5C, square and diamond-shaped suction holes H are shown in addition to the circular shape, but this is only an example, and suction of various shapes such as an ellipse, a pentagon or more polygon, and a rectangle. The hole H may be adopted.

  In addition, as a region for forming the suction hole H, it is preferable to adopt a region within a range of 30% width from the lower blade 221 with respect to the entire width of the main body portion 21. In addition, as a region for forming the suction hole H, a region within a range of 30% of the width from the end face 23a may be employed with respect to the entire width of the rotating body 2. Thereby, when wrinkle SW etc. generate | occur | produce, a negative pressure can be mainly applied to an unpreferable area | region, and a negative pressure can be efficiently provided to the film F. In the present embodiment, the lower blade is not limited to 30%, and from the viewpoint of giving negative pressure intensively to a region that is not preferable when wrinkle SW or the like is generated, The region from 221 to 50%, 45%, 15%, 10%, 5%, etc. may be adopted as the region where the suction holes H are provided. Further, the region of 50%, 45%, 15%, 10%, 5%, etc. from the end face 23a may be adopted as the region where the suction hole H is provided with respect to the entire width of the rotating body 2.

  The rotating body 2 is positioned below the upper blade portion 3 as shown in FIG. Therefore, a negative pressure is applied to the film F in the same direction as gravity, and the negative pressure from the rotating body 2 is applied without loss. Therefore, wrinkles and the like generated on the film F can be more reliably suppressed.

  Thus, in this embodiment, since the film cutting device 15 employs a suction roller as the rotating body 2, the film thickness deviation is 3 or more, the variation in tension in the width direction is large, and wrinkles SW are generated. Even if the easy-to-cut film F is cut, it is possible to prevent slit cut defects.

  In addition, since a wrinkle etc. of the film F are suppressed, so that a film thickness deviation is small, the one where a film thickness deviation is small is preferable from a viewpoint of preventing a slit cut defect. On the other hand, in the manufacturing process of the film F, there is a certain limit in reducing the film thickness deviation. From these viewpoints, the film thickness deviation is preferably 2 or more, more preferably 1 or more.

  Moreover, in this Embodiment, the residual solvent amount of the film F at the time of cutting is 30% or less, Preferably it is 20% or less, More preferably, it is 10% or less. In order to realize this, the drying time of the web in the endless belt portion 11 and the stretching amount and the stretching time of the film F in the stretching device 14 may be appropriately adjusted.

  In addition, in the said embodiment, when the structure which cuts the both ends of the width direction of the film F continuously in a conveyance direction is provided in the both ends of the rotary body 2, and the center part of the main-body part 21 is employ | adopted. The suction holes H may be arranged symmetrically so as to increase the proportion of the region where the suction holes H are formed with respect to the region where the suction holes H are not formed as it goes toward the groove portion 22. .

2 Rotating body 3 Upper blade portion 15 Film cutting device 21 Main body portion 22 Groove portion 23 End portion 31 Upper blade 221 Lower blade 311 Taper F Film H H1 to H4 Suction hole SL Slit SW Wrinkle

Claims (5)

A film cutting method for cutting a resin film using a film cutting device,
The film cutting device is
A cylindrical rotating body including a first blade configured by forming a groove on the surface, and transporting a resin film;
A disc-shaped second blade that is disposed rotatably and includes a resin film that is conveyed by the rotating body and is cut in the conveying direction by sandwiching the resin film with the first blade;
The groove is provided on at least one end face side of the rotating body,
The rotating body is a suction roller including a main body provided on the other end face side from the groove and an end provided on the one end face side from the groove , and in the main body , The film cutting method in which the suction holes are arranged so that the ratio of the area where the suction holes are formed to the area where the suction holes are not formed increases as approaching.   The film cutting method according to claim 1, wherein a resin film having a film thickness deviation of 2 or less or a residual solvent amount of 30% or less is cut. The first blade constitutes a lower blade,
The film cutting method according to claim 1, wherein the second blade constitutes an upper blade. The film cutting method according to any one of claims 1 to 3, wherein in the rotating body, the suction hole is formed within a width of 30% from the groove portion with respect to the entire width of the main body portion. A film cutting device for cutting a resin film,
A cylindrical rotating body including a first blade configured by forming a groove on the surface, and transporting a resin film;
A disc-shaped second blade that is disposed rotatably and includes a resin film that is conveyed by the rotating body and is cut in the conveying direction by sandwiching the resin film with the first blade;
The groove is provided on at least one end face side of the rotating body,
The rotating body is a suction roller including a main body provided on the other end face side from the groove and an end provided on the one end face side from the groove , and in the main body , The film cutting device in which the suction holes are arranged so that the ratio of the area where the suction holes are formed to the area where the suction holes are not formed increases as approaching.

Images