JP5647649B2 - Knurling device, knurling method, film roll manufacturing method - Google Patents

Description

  The present invention relates to a knurling apparatus, a knurling method, and a film roll manufacturing method.

  Polymer films are widely used as optical films and the like because of their features such as excellent light transmission and flexibility, and being capable of reducing the weight of thin films. As a polymer film, various films such as a cellulose ester film using cellulose acylate, a PET film, an acrylic film, and the like are known. For example, a cellulose ester film is a photographic photosensitive film or a liquid crystal display device. It is used for optical films, such as a protective film of a polarizing plate which is a structural member, and a retardation film.

  In the process of manufacturing a polymer film, or in the process of manufacturing a film roll by winding the manufactured polymer film into a roll for storage or transportation, minute unevenness called knurling is given to the side of the polymer film. The The knurling is applied by passing the polymer film between a pair of rollers having protrusions formed on at least one peripheral surface, and pressing the protrusions against the polymer film during the passage. The knurling thus imparted has the effect of enhancing the handling of the polymer film and the effect of preventing winding deviation and deformation of the film roll.

  As described above, it is effective to impart knurling to the polymer film. However, when the temperature of the polymer film is low when knurling is applied, the polymer film is pressed in a state in which it is difficult to deform. There are problems such as the inability to form a knurling (the height of the unevenness) and a problem that the polymer film breaks in an attempt to increase the thickness of the knurling. In addition, the formed knurling is likely to be loose (pressing during transportation and storage, and projections become smaller as time passes). For this reason, in the following Patent Documents 1 and 2, the polymer film is pressed by a heated knurling roller to impart knurling. By doing so, it is possible to prevent the settling of the knurling.

JP 2003-175522 A JP 2009-073154 A

  As described above, when the knurling is applied, if the temperature of the polymer film is too low, the knurling is likely to be spoiled. On the other hand, if the temperature of the polymer film is too high, the polymer film is broken or gives the knurling of the intended shape. I can't. For this reason, when the roller is heated, it is necessary to control the temperature of the roller so that the temperature of the polymer film falls within an appropriate temperature range.

  However, in the conventional method, the contact between the roller and the polymer film is only a short period during which the polymer film passes between the rollers, and heating and knurling are simultaneously performed in this short period. For this reason, there has been a problem that it is difficult to control the temperature of the roller, and stable knurling cannot be applied.

  The present invention has been made in view of the above background, and an object of the present invention is to provide a knurling apparatus, a knurling method, and a film roll manufacturing method that enable stable knurling.

  In order to achieve the above object, the knurling device of the present invention conveys a belt-shaped web along the longitudinal direction to pass between the first and second pair of rollers, and the first and second rollers are passed during this passage. In a knurling device that imparts knurling to a web by pressing the projection formed on at least one of the first and second rollers against the web by sandwiching the web from both front and back surfaces with two rollers, at least the first roller is heated. The first roller is disposed upstream of the second roller in the web conveyance direction so that the web passes between the first and second rollers after the web wraps around the outer periphery of the first roller. It is characterized by the arrangement.

  It is preferable to heat the web to a temperature not lower than the glass transition point and not higher than the melting point by a heater.

  It is preferable that the heater induction-heats the heating target roller by generating a magnetic field change in the vicinity of the heating target roller.

  The heater may include a first heater that heats the first roller and a second heater that heats the second roller, and the first and second rollers may be heated by the heater.

  A protrusion may be provided on the outer periphery of the second roller. Further, the protrusion may be provided on the outer periphery of the first roller.

  The wrap angle at which the web wraps around the outer periphery of the first roller is preferably 5 ° or more and 30 ° or less.

  The first and second rollers may be provided on one side and the other side in the width direction of the web, respectively, and knurling may be applied to both sides in the width direction of the web. In this case, it is preferable that the rotation axis of the first and second rollers is inclined with respect to the width direction so as to pull the side portion of the web outward in the width direction by rotation. In addition, it is preferable to incline a rotating shaft in the range of 0.1 degree or more and 1.0 degree or less with respect to the width direction.

  Further, the knurling method of the present invention uses the knurling device described above, wraps the web on the outer periphery of the first roller on the upstream side in the conveying direction, heats it, and then passes between the first and second rollers to impart knurling. It is characterized by doing.

  Furthermore, the film roll manufacturing method of the present invention is characterized by comprising a knurling step for imparting knurling by the knurling method described above, and a winding step for winding the web with knurling.

  In the present invention, after the web is wrapped and heated on the outer periphery of the first roller on the upstream side in the conveying direction, the web is passed between the first and second rollers to impart knurling. For this reason, compared with the case where heating and knurling are simultaneously performed in a short period of time passing between the first and second rollers, the time for heating the web can be lengthened, and the time for heating the web is further wrapped. Since it can be arbitrarily controlled by the angle, the temperature control of the roller is easy, and stable knurling can be imparted.

It is the schematic which shows a film roll manufacturing equipment. It is a perspective view of a knurling device. It is a side view of a knurling device. It is a side view of the knurling apparatus of another form. It is a side view of the knurling apparatus of another form. It is a side view of the knurling apparatus of another form. It is a perspective view of the knurling apparatus of another form. It is a top view of the knurling apparatus of another form.

  As shown in FIG. 1, the film roll manufacturing facility 10 of the present invention includes a film manufacturing line 12 and a winding device 14. Although not shown, the film production line 12 includes a casting apparatus, a tenter, and a drying apparatus, and produces a strip-shaped polymer film 16 (for example, a TAC (triacetyl cellulose) film) by, for example, a solution casting method.

  The winding device 14 has a turret arm 18 and winds the polymer film 16 around a winding core 22 set on a winding shaft 20. The turret arm 18 is intermittently rotated 180 degrees by an arm driving unit (not shown), and the winding core 22 is selectively switched between the winding position PS1 and the winding core replacement position PS2. A guide arm 24 is provided at an intermediate position in the rotational direction of the turret arm 18, and a guide roller 26 is attached to the distal end portion of the guide arm 24. The guide roller 26 supports the polymer film 16 so that the polymer film 16 does not come into contact with the turret arm 18 or the arm mounting shaft 28 when the turret arm 18 is rotating.

  A winding shaft 20 is provided at the tip of the turret arm 18, and a winding core 22 is set on the winding shaft 20. At the winding position PS <b> 1, the polymer film 16 sent from the conveyance roller 30 is wound around the winding core 22. In addition, at the core replacement position PS2, the film roll 32 that has been fully wound up by winding the polymer film 16 of a certain length is removed from the winding shaft 20 together with the winding core 22, and the winding shaft 20 includes a new one. An empty core 22 is set, and the core 22 is exchanged.

  When the polymer film 16 having a predetermined length is wound around the winding core 22 at the winding position PS1 and the film roll 32 is almost fully wound, the turret arm 18 rotates 180 degrees, and the winding core replacement position PS2 The film roll 32 that is almost fully wound is positioned. An empty winding core 22 is positioned at the winding position PS1. When the film roll 32 reaches a predetermined length, a rewinding device (not shown) is activated to cut the polymer film 16. The rear end portion of the cut preceding film is wound around the film roll 32 at the core replacement position PS2. Further, the leading end of the cut subsequent film is wound around the empty core 22 at the winding position PS1.

  Hereinafter, similarly, the polymer film 16 wound around the winding core 22 becomes a product in the form of the film roll 32 that is continuously fed. The polymer film 16 thus obtained is used as a polarizing plate protective film or a retardation film. Further, the polymer film 16 is provided with an optically anisotropic layer, an antireflection layer, an antiglare function layer, and the like, and is used as a high function film.

  A knurling device 34 is provided between the film production line 12 and the winding device 14. The knurling device 34 includes a knurling roller (second roller) 36, a support roller (first roller) 38, and a temperature control mechanism 40. A plurality of protrusions are provided on the surface of the knurling roller 36, and the knurling device 34 nips the polymer film 16 by the knurling roller 36 and the support roller 38 and polymerizes the protrusions 42 formed on the outer periphery of the knurling roller 36. By pressing against the film 16, a knurling 44 (fine irregularities, see FIG. 2) is imparted to the polymer film 16.

  The temperature control mechanism 40 includes a heater 46, a temperature sensor 48, and a control unit 50. The heater 46 is disposed in the vicinity of the support roller 38 and heats the support roller 38 under the control of the control unit 50. Examples of the heater 46 include a device that applies hot air to the support roller 38, a device that applies infrared light to the support roller 38 using a ceramic heater, or the like, or generates a magnetic field change in the vicinity of the support roller 38. Various types can be used, such as those that induction heat. When the support roller 38 is induction-heated, the support roller 38 is formed of a ferromagnetic metal such as iron, SUS440, or a super hard material, or a metal including the same.

  The temperature sensor 48 includes, for example, a thermocouple and a radiation thermometer, and measures the temperature of the support roller 38 at all times or at a predetermined cycle and notifies the controller 50 of the temperature. Based on the information from the temperature sensor 48, the control unit 50 drives and controls the heater 46 so that the support roller 38 is within a predetermined temperature range set in advance.

  Note that the temperature of the polymer film 16 when the knurling 44 is applied (that is, when the polymer film 16 passes between the knurling roller 36 and the support roller 38) is higher than the glass transition point and lower than the melting point. Thus, it is preferable to control the temperature of the support roller 38. Specifically, it is preferable to maintain the temperature of the support roller 38 at the glass transition point or higher and the melting point or lower of the polymer film 16.

  When the temperature of the support roller 38 is lower than the glass transition point of the polymer film 16, there are problems that a knurling having a sufficient thickness cannot be formed and that the polymer film is broken. Also, the knurling is easy to stick. On the other hand, when the temperature of the support roller 38 is higher than the melting point of the polymer film 16, there are problems that the polymer film breaks and that knurling having the intended shape cannot be formed. Such a problem becomes more conspicuous when a thin polymer film is transported than when a thick polymer film is transported. The term “thick” means, for example, a range of 60 μm or more, particularly a range of 60 μm or more and 80 μm or less. Further, the term “thin” means, for example, a range where the thickness is less than 60 μm, particularly a range of 15 μm or more and 40 μm or less.

  As shown in FIG. 2, the knurling roller 36 and the support roller 38 are respectively provided on both sides of the polymer film 16. The knurling 44 is applied to both sides of the polymer film 16. Similarly, a heater 46 and a temperature sensor 48 (not shown in FIG. 2) are also provided on both sides of the polymer film 16 corresponding to the support roller 38. Then, the control unit 50 (not shown in FIG. 2) drives and controls the heater 46 so that the knurlings 44 on both sides of the polymer film 16 are formed under optimum conditions.

  In this way, by controlling the temperature of the support roller 38 and keeping the temperature of the polymer film 16 within an appropriate range, the above-described problems can be prevented and stable knurling 44 can be applied. However, if the contact time between the support roller and the polymer film is short, it is difficult to control the temperature of the support roller so that the polymer film reaches an appropriate temperature within this short time, and stable knurling can be imparted. Can not.

  For this reason, as shown in FIG. 3, in the knurling device 34, the support roller 38 is disposed upstream of the knurling roller 36 in the transport direction A of the polymer film 16. As a result, the polymer film 16 is first brought into contact with the support roller 38 and is conveyed between the knurling roller 36 and the support roller 38 while maintaining this state (that is, while being heated by the support roller 38). Is granted. In this manner, in the knurling device 34, the contact time between the support roller 38 and the polymer film 16 (time for heating the polymer film 16) can be increased, so that the temperature control of the support roller 38 is easy.

  The angle (hereinafter referred to as the rotation angle) of the support roller 38 until the polymer film 16 comes into contact with the support roller 38 and is nipped between the knurling roller 36 and the support roller 38 (until the knurling 44 is applied). The wrap angle θ1 is preferably determined so that the temperature of the polymer film 16 when the knurling 44 is applied is not less than the glass transition point and not more than the melting point. Specifically, the wrap angle θ1 is preferably 5 ° or more and 30 ° or less. Since the contact time between the polymer film 16 and the support roller 38 becomes longer as the wrap angle θ1 becomes larger, the temperature control of the support roller 38 becomes easier. On the other hand, if the wrap angle θ1 is too large, the polymer film 16 whose strength is reduced by heating may be broken or deformed.

  Further, since the appropriate wrap angle θ1 varies depending on the temperature of the support roller, the wrap angle θ1 may be determined according to the temperature of the support roller. Specifically, the wrap angle θ1 is decreased when the temperature of the support roller is high, and the wrap angle θ1 is increased when the temperature of the support roller is low. Similarly, since the appropriate temperature of the support roller varies depending on the wrap angle θ1, it may be determined in which range the temperature of the support roller is maintained according to the wrap angle θ1. Of course, both the wrap angle θ1 and the temperature of the support roller may be changed so that good knurling is formed.

  Further, the factors affecting the formation of the knurling include, as described above, the temperature of the support roller 38 and the wrap angle θ1, the conveyance speed of the polymer film 16, the nip pressure of the polymer film 16 when the knurling 44 is applied, and Examples of the characteristics of the polymer film 16 (thermal conductivity, temperature function of Young's modulus, elastic deformation rate, etc.) can be given. It is preferable to set each of these factors so that good knurling is formed. Of course, good knurling may be formed by setting one or more of these factors to a target value and changing other factors (for example, setting a target transport speed). The temperature of the support roller 38 and the wrap angle θ1 may be adjusted so that good knurling can be formed at this conveyance speed).

  As described above, in the present invention, the polymer film is wrapped around the outer periphery of the support roller on the upstream side in the transport direction and heated, and then passed between the support roller and the knurling roller to give the knurling. The temperature can be easily controlled, and stable knurling can be imparted.

  In addition, according to the present invention, since the handling of the polymer film is improved by providing stable knurling as described above, the polymer film can be conveyed at high speed without increasing the conveying tension of the polymer film. That is, in the production and winding of the polymer film, it is preferable to increase the conveyance speed in order to improve productivity. However, if the transport speed of the polymer film is high, the transport roller that transports the polymer film may slip and the polymer film may be damaged, and this scratch becomes a fatal defect especially in optical functional films. End up. In the present invention, since the handling of the polymer film can be improved, such a problem can be prevented.

  Further, when the conveyance tension is increased in order to prevent the above-mentioned slip, the polymer film may be deformed by a residual stress during or during conveyance. In the present invention, since the handling of the polymer film can be improved, it is not necessary to increase the conveyance tension, and such a problem can be prevented. As described above, the problem of deformation caused by increasing the conveyance tension is that a relatively thin polymer film (for example, a thickness of 15 mm) is more than the case of conveying a relatively thick polymer film (for example, a thickness of 60 μm to 80 μm). It is more remarkable when transporting ~ 40 μm). For this reason, this invention is especially effective when conveying a comparatively thin polymer film. The preferable range of the transport tension is 10 to 60 N / m. If the conveyance tension is less than 10 N / m, the tension is too low, and the surface of the polymer film is wavy. On the other hand, if the conveyance tension exceeds 60 N / m, the tension is too high, and a tin-like streak deformation occurs on the surface of the polymer film. Also, the low conveyance speed means that the conveyance speed is higher than 10 m / min and is 40 m / min or less, and the high conveyance speed means that the conveyance speed is higher than 40 m / min and 150 m / min or less. Show.

  Furthermore, according to the present invention, the above-described effects can be obtained with a simple configuration, so that the cost can be reduced. That is, as a method for high-speed conveyance without increasing the conveyance tension, a method is known in which a groove is provided on the surface of the conveyance roller to eliminate air between the conveyance roller and the polymer film. There is no need to use a transport roller. Further, when such a special transport roller is used, there is a risk that a mark such as a groove may remain in the polymer film, but the present invention does not have such a problem. Furthermore, according to the present invention, a knurling having a sufficient thickness can be provided, so that air between the conveying roller and the polymer film can be discharged from the knurling gap. The effect similar to the case where a special conveyance roller is used can be obtained without using it. Furthermore, according to the present invention, it is possible to stably give good knurling that is thick and difficult to set, so that in the form of a film roll wound with a polymer film, the effect of preventing film misalignment is high. .

  In the present invention, since the support roller is heated and the support roller is disposed upstream of the knurling roller, and the web can be heated before the knurling is applied, the detailed configuration is limited to the above embodiment. It can be changed as appropriate. For example, you may apply this invention to the knurling apparatus which provides knurling to webs other than a polymer film.

  Further, the web may be a single layer or a multilayer (for example, a plurality of thin films formed on a plastic support). Further, the web is not limited to those having optical functionality, such as a recording medium in which a vapor deposition layer or a coating layer is formed on a resin film, a moisture-proof and air-proof film in which an organic film or an inorganic film is laminated on a resin film, etc. Various types can be used.

  Further, the temperature sensor is used to measure the temperature of the support roller, and the temperature of the support roller is controlled based on the measurement result. However, the temperature sensor is used to measure the temperature of the polymer film, and based on the measurement result. The temperature of the support roller may be controlled. Moreover, a temperature sensor may be abolished and a fixed heat | fever according to the conditions at the time of providing knurling, such as a conveyance speed of a polymer film, may be supplied to a support roller from a heater.

  Moreover, although the example which gives a knurling between a film production line and a winding apparatus demonstrated, the knurling apparatus of this invention is arrange | positioned in a film production line, and a knurling is provided with respect to the film under manufacture. May be.

  Furthermore, like the knurling device 60 shown in FIG. 4, a heater 46 similar to the above-described embodiment may be added to heat the knurling roller 36. In the description using FIG. 4 and subsequent drawings, the same members as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  Further, a projection 42 may be provided on the outer periphery of the support roller 38 as in the knurling device 70 shown in FIG. Moreover, you may provide a protrusion only in the outer periphery of a support roller. Furthermore, you may provide a hollow in the outer periphery of a support roller or a knurling roller instead of a protrusion. Of course, a protrusion may be provided on one of the support roller and the knurling roller, and a recess may be provided on the other.

  Furthermore, after giving knurling, the polymer film also wraps around the knurling roller, i.e., the polymer film transport direction toward the support roller is parallel to the polymer film transport direction after leaving the knurling roller ( As described in FIG. 3), as in the knurling device 80 shown in FIG. 6, the transport direction A of the polymer film 16 toward the support roller 38 and the transport direction B of the polymer film 16 after being separated from the knurling roller 36. The polymer film 16 may be brought into contact with the knurling roller 36 only when the knurling 44 is applied.

  Moreover, you may use the one support roller 72 long in the width direction of the polymer film 16 like the knurling apparatus 90 shown in FIG. In this knurling device 90, both side portions 72 a of the support roller 72 are formed from a material having high thermal conductivity to the polymer film 16 (for example, iron or stainless steel), and the central portion 72 b is thermally conductive to the polymer film 16. It is formed from a material with low properties (for example, zirconia, fluororesin, etc.). By doing so, deformation and alteration due to heat in a portion where the knurling 44 is not applied is prevented. In addition, a material having high thermal conductivity to the polymer film 16 is coated on the outer periphery of both side portions 72a of the support roller 72, or a material having low heat conductivity to the polymer film 16 is applied to the outer periphery of the central portion 72b of the support roller 72. By coating, the deformation or alteration of the portion not provided with the knurling 44 due to heat may be prevented.

  Of course, like the support roller 72, a single knurling roller that is long in the width direction of the polymer film 16 may be used. In this case, it is only necessary to provide a protrusion or a depression on the portion of the outer periphery of the knurling roller that imparts knurling (the outer periphery of both sides of the knurling roller).

  Furthermore, the support roller 38 and the knurling roller 36 may be inclined with respect to the transport direction A of the polymer film 16 as in the knurling device 100 shown in FIG. In the example of FIG. 6, the support roller 38 and the knurling roller 36 are inclined outward by an angle θ2 with respect to the transport direction A. By doing so, when the polymer film 16 passes between the support roller 38 and the knurling roller 36, the polymer film 16 is pulled outward in the width direction, so that wrinkles and the like can be prevented. If the angle θ2 is too small, a sufficient effect cannot be obtained. If the angle θ2 is too large, the polymer film may be broken. For this reason, it is preferable that angle (theta) 2 is the range of 0.1 degree-1 degree.

  In the above-described embodiment, the example in which the polymer film before knurling is heated by heating the support roller has been described. For example, the polymer film before knurling is heated by blowing hot air from a heater. May be. Of course, the polymer film may be directly heated by a heater. Alternatively, the polymer film may be heated by increasing the temperature of the room in which the knurling apparatus is stored or by passing the room through a high temperature chamber before applying the knurling. In addition, some film production lines have a high-temperature drying chamber for drying the film being manufactured, so a knurling device can be installed in this drying chamber or the polymer film before knurling is passed. By heating, the polymer film may be heated.

  Hereinafter, based on Tables 1 and 2, specific Examples 1 to 12 of the present invention will be described in comparison with Comparative Examples 1 to 6.

  In Tables 1 and 2, in Examples 1 to 12, as described in the above-described embodiment, the support roller is disposed upstream of the knurling roller (the wrap angle θ1 is set to be larger than 0 °). Was used. On the other hand, in Comparative Examples 1 to 6, a conventional knurling device with a wrap angle θ1 of 0 ° was used.

  Moreover, in all the Examples and Comparative Examples, a cellulose triacetate film was used as a polymer film, and after knurling the film and wound up, the state of knurling, film, and film roll was evaluated. Furthermore, the film conveyance speed (winding speed) was 100 m / min, and the load (nip pressure) at the time of knurling was 30 kgf. The angle θ2 was 0 °.

  In Table 1 (Examples 1 to 6, Comparative Examples 1 to 4), knurling was applied to both sides of a film having a thickness of 60 μm, and in Table 2 (Examples 6 to 12, Comparative Examples 5 and 6), the thickness was given. Knurled on one side of a 40 μm film. In addition, the temperature of the support roller and the knurling roller and the wrap angle θ1 in each example and each comparative example are as shown in Tables 1 and 2.

  In Table 1, Examples 1 to 6 and Comparative Examples 1 to 4 were evaluated for 5 items of knurling thickness, cracking, settling rate, scratches, and comprehensive evaluation. In addition, "-" has shown that it was out of evaluation object, because the film was torn and the winding had to be stopped.

  The knurling thickness was measured by using a thickness measuring instrument (IDC-112) manufactured by Mitutoyo Co., Ltd. to measure the difference between the apex portion of the convex portion of the knurling and the non-knurled portion, and this was defined as the knurling thickness. The knurling thickness is preferably thicker.

  For the cracking, visually observe how many cracks there are per 500 mm of the knurling with a magnifying glass of 5 times, "A" if the crack could not be confirmed, "B" if the crack was 10 or less When the number of cracks was 10 or more, “C” was assigned. In addition, it is so preferable that there are few cracks, ie, it goes to "A" from "C".

  The settling rate indicates a reduction rate of the knurling thickness when a φ100 roller is applied with a tension of 100 N / m and held for 1 minute in a 120 ° DRY environment. It is preferable that the settling rate is small.

  The scratches were visually observed on the film after being wound on the 500 rollers at 80 N / m. When the scratches could not be confirmed, “A”, there was a scratch, but the length was 1 mm. If it was less than “B”, the length was “C” if there was a scratch with a length of 1 mm or more. In addition, the smaller the scratch, that is, the more preferable it is from “C” to “A”.

  Comprehensive evaluation is based on comprehensive evaluation of each evaluation item (in the case of Table 1, four items of knurling thickness, cracking, settling rate, and scratches). To “C”. On the other hand, when there was a problem as a product and improvement was required, it was set as “D”.

  As shown in Table 1, Examples 1 to 6 and Comparative Examples 1 to 4 in which knurling was applied while changing the conditions for a film having a thickness of 60 μm were compared. It was found that the evaluation was higher in all of the knurling thickness, cracking, settling rate, and scratches than 4 and the overall evaluation was also good. Further, it has been found that as the wrap angle θ1 is increased, the knurling thickness is thicker and good knurling with a low settling rate can be imparted.

  Furthermore, it can be confirmed from Table 1 that the film handling can be enhanced by the present invention. That is, in the evaluation of scratches, Examples 1 to 6 are highly evaluated and can prevent the problem that the conveyance roller slips. In Comparative Examples 1 to 4, the evaluation is low and the conveyance roller slips. It was.

  Subsequently, in Table 2, with respect to Examples 7 to 12 and Comparative Examples 5 and 6, four items of knurling thickness, cracking, change with time, and comprehensive evaluation were evaluated. In addition, about knurling thickness, a crack, and comprehensive evaluation, since it evaluated on the same evaluation criteria as Table 1, description is abbreviate | omitted.

  The change with time was that the wound film roll was stored in an environment of 23 ° C. and 50% humidity for 2 weeks, and the deformation of the film roll was visually observed. If there was no deformation, “A”, almost no deformation. If it was not, “B” was indicated, “C” was indicated when there was a slight deformation but there was no problem as a product, and “D” was indicated when the deformation was so large that the film roll had a deformation mark. It is to be noted that the smaller the change with time, that is, the more preferable is the direction from “D” to “A”.

  As shown in Table 2, Examples 7 to 12 and Comparative Examples 5 and 6 to which knurling was applied while changing the conditions for a film having a thickness of 40 μm were compared. As a result, Examples 7 to 12 were Comparative Example 5, It was found that the knurling thickness was thicker than 6, and there was no crack, and the overall evaluation was good. However, it was found that as the wrap angle θ1 is increased and the temperature of the knurling roller is higher, the knurling thickness is increased and the change with time is also increased.

  Further, from Table 2, it was confirmed that the film roll could be prevented from being displaced by the present invention. That is, in the evaluation of changes over time, Examples 7 to 12 were highly evaluated, and the film roll was prevented from being displaced after being made a film roll, so that the deformation of the film roll was suppressed, and Comparative Examples 5 and 6 were films with a low evaluation. It was found that the film rolls were deformed due to a shift between the overlapping films after being rolled.

  Furthermore, from Tables 1 and 2, it can be confirmed that the present invention is effective not only for a relatively thick film having a thickness of 60 μm but also for a relatively thin film having a thickness of 40 μm. It was. It was also confirmed that the present invention is effective even when the film transport speed is as high as 100 m / min.

  Thus, since the effectiveness of the present invention was confirmed for the case of imparting knurling to the cellulose triacetate film, the verification of the effectiveness of the present invention in the case of imparting knurling to the PET film was performed next. went. The results are shown in Table 3.

  In Table 3, the effectiveness of the present invention was verified using TAC1 that gave knurling to the cellulose triacetate film and PET1 to 4 that gave knurling to the PET film. The conditions at the time of giving knurling are as shown in the table, and the evaluation is the same as in the above-described Tables 1 and 2, and the description thereof will be omitted.

  As shown in Table 3, PET 2 to 4 with a wrap angle larger than 0 ° are better evaluated than PET 1 with a wrap angle of 0 °, and the effectiveness when applied to the present invention on a PET film is better. It could be confirmed.

  Moreover, when the conditions are the same between the cellulose triacetate film and the PET film, the PET film can give better knurling (see the results of TAC1 and PET3), but the present invention is applied to the cellulose triacetate film. In the case where the present invention was not carried out on the PET film, it was found that better knurling could be imparted when the present invention was carried out on the cellulose triacetate film (see the results of TAC1 and PET1). That is, even if it was a cellulose triacetate film which is difficult to give better knurling than a PET film, it turned out that a knurling better than the PET film which does not carry out the present invention can be given by carrying out the present invention.

  The reason why cellulose triacetate film is more difficult to give better knurling than PET film is that cellulose triacetate film has higher mechanical strength but lower breaking strength (brittle), and it deforms when force is applied. Since it is difficult and it is easy to crack, if it is not fully heated to the inside of a film, it will be cracked before becoming a required deformation (thickness of a knurling). On the other hand, since TAC1 which implemented this invention can provide a better knurling than PET1 which does not implement this invention, it turned out that it is fully heated to the inside of a film. As described above, according to the present invention, the inside of the film is sufficiently heated. Therefore, it is particularly effective to implement the present invention on a cellulose triacetate film that is not easily deformed and easily broken.

  Thus, the effectiveness of the present invention could be confirmed regardless of the type of film, so that the wrap angle was kept constant and the temperature of the knurling roller and the support roller was changed to optimize the knurling roller and the support roller. The temperature was verified. The results are shown in Table 4.

  In Table 4, the optimum temperatures of the knurling roller and the support roller were verified using TACs 2 to 7 which gave knurling to the cellulose triacetate film. The conditions for giving knurling are as shown in the table. As described above, it has been proven that the present invention is effective regardless of the temperature of the knurling roller and the support roller (see Tables 1 to 3). That is, in Table 4, even if it is evaluated whether or not it is a level having a quality problem, all pass (a level without a quality problem), and the influence of the temperature difference between the knurling roller and the supporting roller on the knurling. I do not understand. For this reason, in Table 4, the range having no quality problem is further divided into three stages, and evaluations of “1” to “3” are given in order of goodness.

  As shown in Table 4, it was found that when the temperature of the knurling roller and the support roller was increased from 100 ° C, the knurling quality was improved as the temperature increased until these temperatures reached 180 ° C. . Further, it was found that when the temperature of the knurling roller and the support roller was decreased from 340 ° C., the knurling quality was improved as the temperature decreased until these temperatures reached 300 ° C. Furthermore, it has been found that the knurling quality is maintained in a good state when the temperature of the knurling roller and the support roller is in the range of 180 ° C to 300 ° C. From these, it was found that the temperature of the knurling roller and the supporting roller was in the range of 180 ° C. to 300 ° C. was an appropriate range in which the film was sufficiently heated to the inside and not excessively heated.

DESCRIPTION OF SYMBOLS 10 Film roll manufacturing equipment 12 Film manufacturing line 14 Winding apparatus 16 Polymer film 32 Film roll 34, 60, 70, 80, 90, 100 Knurling apparatus 36 Knurling roller (2nd roller)
38, 72 Support roller (first roller)
40 Temperature Control Mechanism 44 Knurling 46 Heater 48 Temperature Sensor 50 Control Unit

Claims (14)

The belt-shaped web is conveyed along the longitudinal direction and passed between the first and second pair of rollers, and the web is sandwiched from both the front and back surfaces by the first and second rollers during the passage. 1. In a knurling device for imparting knurling to the web by pressing a protrusion formed on the outer periphery of at least one of the second rollers against the web,
A heater for heating at least the first roller;
The first roller is disposed upstream of the second roller in the conveyance direction of the web so that the web passes between the first and second rollers after wrapping the outer periphery of the first roller. and,
A knurling device , wherein the protrusion is provided on an outer periphery of the first roller .   The knurling apparatus according to claim 1, wherein the web is heated to a temperature not lower than a glass transition point and not higher than a melting point by the heater.   3. The knurling apparatus according to claim 1, wherein the heater performs induction heating of the roller to be heated by generating a magnetic field change in the vicinity of the roller to be heated.   The heater includes a first heater that heats the first roller and a second heater that heats the second roller, and the first and second rollers are heated by the heater. The knurling device according to any one of claims 1 to 3.   The knurling device according to claim 1, wherein the protrusion is provided on an outer periphery of the second roller. Claim 1-5 knurling device according to any one of, wherein the web is the wrap angle of wrap the outer periphery of the first roller is 5 ° or more than 30 °. The first and second rollers are respectively provided on one side and the other side in the width direction of the web,
The said knurling is given to the width direction both sides of the said web, The knurling apparatus in any one of Claims 1-6 characterized by the above-mentioned. 8. The knurling according to claim 7 , wherein the first and second rollers have a rotation axis inclined with respect to the width direction so as to pull a side portion of the web outward in the width direction by rotation. apparatus. The knurling device according to claim 8 , wherein the rotation shaft is inclined in a range of 0.1 ° to 1.0 ° with respect to the width direction. Using the knurling device according to any one of claims 1 to 9 , after the web is wrapped and heated on the outer periphery of the first roller on the upstream side in the conveying direction, the knurling is imparted by passing between the first and second rollers. A knurling method characterized by A knurling step of imparting knurling by the knurling method according to claim 10 ;
A film roll manufacturing method comprising: a winding step of winding the web provided with the knurling. The belt-shaped web is conveyed along the longitudinal direction and passed between the first and second pair of rollers, and the web is sandwiched from both the front and back surfaces by the first and second rollers during the passage. 1. In a knurling device for imparting knurling to the web by pressing a protrusion formed on the outer periphery of at least one of the second rollers against the web,
A heater for heating at least the first roller;
The first roller is disposed upstream of the second roller in the conveyance direction of the web so that the web passes between the first and second rollers after wrapping the outer periphery of the first roller. And
A knurling apparatus, wherein a wrap angle at which the web wraps around an outer periphery of the first roller is 5 ° or more and 30 ° or less. The belt-shaped web is conveyed along the longitudinal direction and passed between the first and second pair of rollers, and the web is sandwiched from both the front and back surfaces by the first and second rollers during the passage. 1. In a knurling device for imparting knurling to the web by pressing a protrusion formed on the outer periphery of at least one of the second rollers against the web,
A heater for heating at least the first roller;
The first roller is disposed upstream of the second roller in the conveyance direction of the web so that the web passes between the first and second rollers after wrapping the outer periphery of the first roller. And
The first and second rollers are respectively provided on one side and the other side in the width direction of the web,
The knurling is applied to both sides in the width direction of the web,
The knurling device, wherein the first and second rollers have a rotation axis inclined with respect to the width direction so as to pull the side portion of the web outward in the width direction by rotation. The knurling device according to claim 13, wherein the rotation shaft is tilted in a range of 0.1 ° to 1.0 ° with respect to the width direction.

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