KR102201006B1 - Knurling apparatus, knurling method, and film roll manufacturing method - Google Patents

Abstract

The knurling device 34 nips the polymer film 16 by a knurling roller 36 having a protrusion 42 formed on the outer circumference thereof and a support roller 38 heated by a heater 46, and the knurling roller 36 The protrusion 42 of) is pressed against the polymer film 16 to impart knurling to the polymer film 16. The support roller 38 is disposed upstream of the conveyance direction A of the polymer film 16 from the knurling roller 36. The polymer film 16 first comes into contact with the support roller 38 and is conveyed between the channeling roller 36 and the support roller 38 maintained in this state, and knurling is provided.

Description

Knurling device, knurling method, film roll manufacturing method {KNURLING APPARATUS, KNURLING METHOD, AND FILM ROLL MANUFACTURING METHOD}

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

Polymer films have excellent light transmittance and flexibility, and are used in a wide variety of fields as optical films because of their advantages such as being able to form a thin film with a light weight. As a polymer film, various films, such as a polyethylene terephthalate (PET) film, and an acrylic film, are known, including a cellulose ester-based film using cellulose acylate or the like. For example, a cellulose ester film is used for optical films, such as a film for photographic photosensitization, a polarizing plate which is a constituent member of a liquid crystal display, and a retardation film.

In the process of manufacturing a polymer film, or in the process of manufacturing a film roll by winding the produced polymer film in a roll shape for storage or transportation, minute irregularities called knurling are provided on the side of the polymer film. The knurling is provided by passing a polymer film between a pair of rollers with projections formed on at least one circumferential surface, and pressing the projections against the polymer film during the passage. The knurling provided in this way has an action of enhancing the handling of the polymer film and an action of preventing misalignment or deformation of the film roll.

As described above, it is effective to impart knurling to the polymer film. However, if the temperature of the polymer film is low when knurling is applied, the polymer film is pressed in a state where it is difficult to deform, so the problem of not being able to form knurling of sufficient thickness (height of the unevenness) or trying to increase the thickness of the knurling There is a problem such as cracking of the polymer film. In addition, settlement is likely to occur in the formed knurling. Settling is the pressure during transportation or storage, or the protrusion becomes smaller with the passage of time. For this reason, in JP 2003-175522 A and JP 2009-073154 A, a polymer film is pressed with a heated knurling roller to impart knurling. By doing so, it is possible to prevent the knurling from sinking.

As described above, when the temperature of the polymer film is too low when knurling is applied, the knurling is likely to settle. On the contrary, when the temperature of the polymer film is too high, the polymer film is broken or knurling of the intended shape cannot be provided. For this reason, when heating the roller, 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 technique, the contact between the roller and the polymer film is only a small period for the polymer film to pass between the rollers, and heating and knurling are simultaneously performed during this small period. For this reason, there is a problem that it is difficult to control the temperature of the roller, and it is impossible to provide a stable knurling.

An object of the present invention is to provide a knurling apparatus, a knurling method, and a film roll manufacturing method in which stable knurling can be provided.

The knurling apparatus of the present invention includes a first roller and a second roller, a projection, and a first heater, and provides knurling to a belt-shaped web conveyed in the longitudinal direction. The first roller and the second roller hold the web from both sides. The first roller is disposed upstream of the conveying direction of the web than the second roller so that the web passes between the first roller and the second roller after wrapping the outer periphery of the first roller. The protrusion is formed on the outer periphery of at least one of the first roller and the second roller. The protrusion is pressed against the web by the pinch between the first roller and the second roller, and knurling is applied. The first heater heats the first roller.

It is preferable to heat the web to a temperature equal to or higher than the glass transition point and lower than the melting point by means of a heater.

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

It is preferred to have a second heater that heats the second roller.

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

It is preferable that the first roller and the second roller are provided on one side portion and the other side portion in the width direction of the web, respectively, and knurling is provided to both sides in the width direction of the web.

It is preferable that the first roller and the second roller have a rotation shaft inclined with respect to the width direction so that the side portion of the web is pulled outward in the width direction by rotation.

It is preferable that the rotating shaft is inclined in the range of 0.1° or more and 1.0° or less with respect to the width direction.

The knurling method of the present invention includes a heating step and a knurling step, and provides knurling to a strip-shaped web conveyed in the longitudinal direction. The heating step heats the web with the first roller. The web is heated by wrapping the outer periphery of the first roller having a heater and conveying it. In the knurling step, the web after wrapping the first roller is pinched by the first roller and the second roller to impart knurling. A projection is formed on the outer periphery of at least one of the first roller and the second roller. Knurling is applied by pressing the projections to the web.

The web roll manufacturing method of the present invention includes a heating step, a knurling step, and a winding step. The heating step heats the web with the first roller. The web is heated by wrapping the outer periphery of the first roller having a heater and conveying it. In the knurling step, the web after wrapping the first roller is pinched by the first roller and the second roller to impart knurling. A projection is formed on the outer periphery of at least one of the first roller and the second roller. Knurling is applied by pressing the projections to the web. The winding step winds up the web to which knurling was applied.

According to the present invention, compared to the case where heating and knurling are simultaneously performed in a short period passing between the first and second rollers, the time to heat the web can be lengthened, and the time to heat the web is reduced. It can be arbitrarily controlled according to the wrapping angle. For this reason, temperature control of the roller is easy, and stable knurling can be provided.

The above objects and advantages will be readily understood by those skilled in the art by reading a detailed description of a preferred embodiment with reference to the accompanying drawings.
1 is a schematic diagram showing a film roll manufacturing facility.
2 is a perspective view of a knurling device.
3 is a side view of the knurling device.
4 is a side view of another type of knurling device.
5 is a side view of another type of knurling device.
6 is a side view of another type of knurling device.
7 is a perspective view of another type of knurling device.
8 is a top view of another type of knurling device.

As shown in FIG. 1, the film roll manufacturing equipment 10 has a film manufacturing line 12 and a take-up device 14. The film production line 12, although not shown, has a flexible device, a tenter, and a drying device. For example, a strip-shaped polymer film 16 (for example, TAC (triacetylcellulose) Film).

The take-up device 14 has a turret arm 18 and winds the polymer film 16 around a core 22 set in the take-up shaft 20. The turret arm 18 intermittently rotates 180 degrees by an arm drive (not shown) to selectively switch the winding core 22 into a winding position PS1 and a winding core exchange position PS2. However, a guide arm 24 is installed at an intermediate position in the rotation direction of the turret arm 18, and a guide roller 26 is mounted at the tip end of the guide arm 24. The guide roller 26 supports the polymer film 16 so that the polymer film 16 does not contact 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 PS1, the polymer film 16 sent from the conveying roller 30 is wound around the winding core 22. In addition, at the core exchange position PS2, the polymer film 16 of a certain length is wound and the fully wound film roll 32 is separated from the take-up shaft 20 together with the coil core 22, and the take-up shaft 20 A new empty core 22 is set in ), and the winding core 22 is replaced.

At the winding position (PS1), when the polymer film 16 of a predetermined length is wound around the winding core 22, and the film roll 32 is all close to winding, the turret arm 18 rotates 180 degrees, The film roll 32 close to the whole winding is located in the exchange position PS2. In addition, an empty core 22 is positioned at the take-up position PS1. When the film roll 32 reaches a predetermined length, a rewinding device (not shown) is operated, and the polymer film 16 is cut. The rear end of the cut preceding film is wound around the film roll 32 at the core exchange position PS2. Moreover, the leading end of the cut trailing film is wound up to the empty core 22 at the winding position PS1.

Hereinafter, similarly, by winding the polymer film 16 around the core 22, the polymer film 16 sent continuously becomes a product in the form of the film roll 32. The polymer film 16 thus obtained is used as a polarizing plate protective film and a retardation film. Further, the polymer film 16 is provided with an optically anisotropic layer, an antireflection layer, an anti-glare function layer, and the like, and is used as a high-functional film.

A knurling device 34 is provided between the film production line 12 and the take-up 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 42 are formed on the surface of the knurling roller 36. The knurling device 34 nips (pinches) the polymer film 16 with the knurling roller 36 and the support roller 38, and attaches the protrusion 42 formed on the outer periphery of the knurling roller 36 to the polymer film 16. ) To give the polymer film 16 knurled (fine irregularities) 44 (see Fig. 2).

The temperature control mechanism 40 is composed of 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 to heat the support roller 38 under the control of the control unit 50. As the heater 46, it is supported by blowing hot air to the support roller 38, emitting infrared rays to the support roller 38 by a ceramic heater, etc., or by generating a magnetic field change in the vicinity of the support roller 38. Various types of things such as induction heating of the roller 38 can be used. However, in the case of induction heating the support roller 38, the support roller 38 is formed of a ferromagnetic metal such as iron, SUS440, or cemented carbide, or a metal including at least one of them.

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

However, the control unit 50 is 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). It is preferable to control the temperature of the support roller 38 so that the temperature of is not less than the glass transition point and not more than the melting point. Specifically, it is preferable to maintain the temperature of the support roller 38 at a glass transition point or more and a melting point or less of the polymer film 16.

When the temperature of the support roller 38 is higher than the glass transition point of the polymer film 16, knurling of sufficient thickness is more reliably formed or cracking of the polymer film is more reliably avoided compared to the case where the temperature of the support roller 38 is lower than the glass transition point. do. In addition, knurling is difficult to settle. Conversely, when the temperature of the support roller 38 is less than or equal to the melting point of the polymer film 16, the polymer film is more difficult to break than the case where it is higher than the melting point, and knurling of the intended shape is more reliably formed. Such an effect becomes more remarkable in the case of conveying a thin polymer film than the case of conveying a thick polymer film. However, when the thickness is thick, for example, it indicates a range in which the thickness is 60 μm or more, in particular, 60 μm or more and 80 μm or less. In addition, the thin thickness indicates, for example, a range in which the thickness is less than 60 µm, particularly, in 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 provided on both sides of the polymer film 16, respectively. And the knurling 44 is provided on both sides of the polymer film 16. Similarly, the heater 46 and the 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. Further, the control unit 50 (not shown in Fig. 2) drives the heater 46 so that the knurling 44 on both sides of the polymer film 16 is formed under optimum conditions, respectively.

In this way, by controlling the temperature of the support roller 38 and maintaining the temperature of the polymer film 16 within an appropriate range, the above-described problem can be prevented and a stable knurling 44 can be provided. 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 temperature is appropriate to the inside of the polymer film in this short time, and stable knurling cannot be provided.

For this reason, in the knurling apparatus 34, as shown in FIG. 3, the support roller 38 is arrange|positioned in the upstream side of the conveyance direction A of the polymer film 16 rather than the knurling roller 36. As shown in FIG. Thereby, the polymer film 16 first comes into contact with the support roller 38, while maintaining this state (that is, while being heated by the support roller 38), the knurling roller 36 and the support roller 38 It is conveyed between and is given a null ring 44. In this way, in the knurling device 34, the contact time between the support roller 38 and the polymer film 16 (time to heat the polymer film 16) can be lengthened, so that the temperature control of the support roller 38 It is easy.

However, after the polymer film 16 comes into contact with the support roller 38, until it is nipped between the knurling roller 36 and the support roller 38 (until the knurling 44 is applied), the support roller 38 The angle at which) rotates (hereinafter, referred to as wrapping angle θ1) is preferably determined so that the temperature of the polymer film 16 at the time of applying the knurling 44 is not less than the glass transition point and not more than the melting point. Specifically, it is preferable that the wrapping angle θ1 is 5° or more and 30° or less. As the wrapping angle θ1 increases, the contact time between the polymer film 16 and the support roller 38 increases, so that the temperature control of the support roller 38 becomes easier. On the other hand, if the wrapping angle θ1 is too large, there is a concern that the polymer film 16 whose strength is reduced by heating may be broken or deformed. However, the wrapping angle θ1 is the same as the angle at which the polymer film 16 wraps the support roller 38.

In addition, since the appropriate wrapping angle θ1 changes according to the temperature of the support roller 38, the wrapping angle θ1 may be determined according to the temperature of the support roller 38. Specifically, the higher the temperature of the support roller 38, the smaller the wrapping angle θ1, and the lower the temperature of the support roller 38, the larger the wrapping angle θ1. Similarly, since an appropriate temperature of the support roller 38 changes according to the wrapping angle θ1, it may be determined in which range the temperature of the support roller 38 is maintained according to the wrapping angle θ1. Of course, both the wrapping angle θ1 and the temperature of the support roller 38 may be changed so that good knurling is formed.

In addition, as factors affecting the formation of the knurling 44, in addition to the temperature and the lapping angle θ1 of the support roller 38 described above, the transport speed of the polymer film 16, and the polymer when the knurling 44 is applied The nipping pressure of the film 16 and the characteristics of the polymer film 16 are mentioned. The properties of the polymer film 16 include thermal conductivity, a temperature function of Young's modulus, and elastic strain. It is desirable to set each of these factors so that good knurling is formed. Of course, one or more of these factors may be set as target values, and good knurling may be formed by changing other factors. For example, a target conveyance speed is set, and the temperature of the support roller 38 and the lapping angle θ1 are adjusted so that satisfactory knurling can be formed at this conveyance speed.

As described above, in the present invention, after wrapping the polymer film on the outer periphery of the support roller on the upstream side in the conveying direction and heating, it is passed between the support roller and the knurling roller to provide knurling, thereby facilitating temperature control of the support roller. By doing so, stable knurling can be provided.

Further, 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 transported at high speed without increasing the transport tension of the polymer film. In production and winding of a polymer film, it is preferable to increase the conveyance speed in order to improve productivity. However, when the conveyance speed of the polymer film is high, the conveyance roller for conveying the polymer film slides, and there is a fear that the polymer film may be scratched. In particular, this scratch becomes a fatal defect in the optical functional film. In the present invention, since the handling of the polymer film can be improved, such a problem can be prevented.

In addition, if the conveyance tension is increased in order to prevent slipping described above, there is a concern that the polymer film may be deformed due to residual stress during conveyance 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 this problem can be prevented. The problem of deformation caused by increasing the conveyance tension is, as described above, compared to the case of conveying a relatively thick polymer film (eg, 60 μm to 80 μm in thickness), a relatively thin polymer film (eg, 15 thickness). Μm to 40 µm) is remarkable. For this reason, this invention is especially effective when conveying a comparatively thin polymer film. However, the preferred range of the conveyance tension is 10 to 60 N/m. By setting the conveyance tension to 10 N/m or more, the tension is too low compared to less than 10 N/m, so that the occurrence of undulations on the surface of the polymer film is more reliably prevented. On the other hand, by setting the conveyance tension to be 60 N/m or less, it is more reliably prevented that the tension is too high to cause a wavy band deformation on the surface of the polymer film as compared to the case where it exceeds 60 N/m. In addition, the conveyance speed is low means that the conveyance speed is faster than 10 m/min and is 40 m/min or less, and the conveyance speed is high means that the conveyance speed is faster than 40 m/min and is 150 m/min or less.

Further, according to the present invention, the above-described effects can be obtained by a simple configuration, and thus cost can be suppressed. That is, as a method of high-speed conveying without raising the conveying tension, a method of removing air between the conveying roller and the polymer film by forming a groove on the surface of the conveying roller is known, but it is not necessary to use such a special conveying roller. Moreover, if such a special conveying roller is used, there is a concern that marks such as grooves may remain on the polymer film, but in the present invention, there is no such problem. In addition, according to the present invention, since knurling of a sufficient thickness can be provided, air between the conveying roller and the polymer film can be discharged from the gap between the knurling, so that a special conveying roller is provided without using the above-described special conveying roller. The same effect as when used can be obtained. Further, according to the present invention, since it is possible to stably impart satisfactory knurling which is difficult to settle due to sufficient thickness, the effect of preventing the film from being rolled up is high in the form of a film roll wound around a polymer film.

However, in the present invention, it is sufficient to heat the support roller and arrange the support roller upstream from the knurling roller, and heat the web before applying knurling, so the detailed configuration is not limited to the above embodiment. You can change it accordingly. For example, the present invention may be applied to a knurling device that imparts knurling to webs other than polymer films.

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

In addition, although the temperature of the support roller 38 is measured by the temperature sensor 48 and the temperature of the support roller 38 is controlled based on the measurement result, the polymer film 16 You may measure the temperature of and control the temperature of the support roller 38 based on this measurement result. Further, without using a temperature sensor, constant heat may be supplied from the heater 46 to the support roller 38 according to the conditions at the time of imparting knurling, such as the conveyance speed of the polymer film 16.

In addition, although an example of providing knurling between the film production line 12 and the take-up device 14 has been described, even if the knurling device of the present invention is disposed in the film production line, knurling is applied to the film during production. do.

Further, like the knurling device 60 shown in Fig. 4, the same heater 46 as in the above-described embodiment may be added to heat the knurling roller 36. However, in the description using the drawings after FIG. 4, the same reference numerals are assigned to the same members as those in the above-described embodiment, and the description is omitted.

Moreover, like the knurling device 70 shown in FIG. 5, the protrusion 42 may be formed on the outer periphery of the support roller 38. In addition, projections may be formed only on the outer periphery of the support roller. That is, the projection may not be formed on the outer circumference of the knurling roller, but may be formed on the outer circumference of the support roller. Further, a groove may be formed on the outer periphery of the support roller or knurling roller instead of the protrusion. Of course, a protrusion may be formed on one of the support roller and the knurling roller, and a groove may be formed on the other side.

In the above embodiment, after applying knurling, the polymer film 16 is also wrapped on the knurling roller 36, that is, the conveying direction of the polymer film 16 toward the support roller 38 and the knurling roller 36 It is an example in which the conveyance direction of the polymer film 16 after moving away from) is parallel (refer FIG. 3). Instead of this aspect, as in the knurling device 80 shown in FIG. 6, the conveying direction (A) of the polymer film 16 facing the support roller 38 and the polymer film 16 after being away 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 provided differently from the conveying direction (B) of.

Further, like the knurling device 90 shown in FIG. 7, one supporting roller 72 long in the width direction of the polymer film 16 may be used. In this knurling device 90, both side portions 72a of the support roller 72 are formed of a material (eg, iron or stainless steel) having high thermal conductivity to the polymer film 16, and the central portion 72b ) Is formed of a material having low thermal conductivity to the polymer film 16 (for example, zirconia or fluororesin). In this way, deformation and deterioration due to heat in the portion not provided with the knurling 44 are prevented. However, coating a material having high thermal conductivity for the polymer film 16 on the outer peripheries of both sides 72a of the support roller 72, or the polymer film 16 on the outer periphery of the central portion 72b of the support roller 72 By coating a material having low thermal conductivity for the knurling 44, deformation and deterioration due to heat may be prevented.

Of course, like the support roller 72, one long knurling roller in the width direction of the polymer film 16 may be used. In this case, a protrusion or groove may be formed in a portion of the outer periphery of the knurling roller (outer peripheries of both sides of the knurling roller) to which knurling is applied.

Moreover, like the knurling apparatus 100 shown in FIG. 8, the support roller 38 and the knurling roller 36 may be inclined with respect to the conveyance direction A of the polymer film 16. In the example of FIG. 8, the support roller 38 and the knurling roller 36 are inclined outwardly by an angle θ2 with respect to the conveying direction A. Here, the angle θ2 is an angle formed between the side surface of the support roller 38 and the side surface of the knurling roller 36 and the conveyance direction A. By arranging the support roller 38 and the knurling roller 36 in this way, when the polymer film 16 passes between the support roller 38 and the knurling roller 36, the polymer film 16 is outside the width direction. As it is traction, wrinkles and the like are prevented. However, if the angle θ2 is too small, a sufficient effect cannot be obtained, and if it is too large, there is a fear that the polymer film may be torn. For this reason, it is preferable that the angle θ2 is in the range of 0.1° to 1°.

In addition, in the above embodiment, the polymer film before knurling is heated by heating the support roller. For example, the polymer film before knurling may be heated by blowing hot air from a heater. Of course, the polymer film may be directly heated by a heater. Further, the polymer film may be heated by raising the temperature of the room in which the knurling device is installed, or by passing through the high-temperature chamber before applying knurling. In addition, some of the film production lines have a high-temperature drying chamber for drying the film during production, and thus the polymer film may be heated by installing a knurling device in the drying chamber or passing the polymer film before knurling.

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

Roller temperature Wrapping angle evaluation Knurling roller Support roller Knurling thickness crack Settlement rate scratch Comprehensive evaluation Example 1 200℃ 200℃ 5° 20㎛ A 40% B C Example 2 200℃ 200℃ 15° 60㎛ A 20% A B Example 3 200℃ 200℃ 30° 80㎛ A 15% A A Example 4 25℃ 200℃ 5° 15㎛ A 50% B C Example 5 25℃ 200℃ 15° 40㎛ A 40% A B Example 6 25℃ 200℃ 30° 60㎛ A 30% A B Comparative Example 1 25℃ 25℃ 0° - - - - - Comparative Example 2 100℃ 100℃ 0° - - - - - Comparative Example 3 200℃ 200℃ 0° 10㎛ B 80% C D Comparative Example 4 25℃ 200℃ 0° - - - - -

Roller temperature Wrapping angle evaluation Knurling roller Support roller Knurling thickness crack Deformed over time Comprehensive evaluation Example 7 200℃ 200℃ 5° 20㎛ A A A Example 8 200℃ 200℃ 15° 25㎛ A A A Example 9 200℃ 200℃ 30° 30㎛ A A A Example 10 25℃ 200℃ 5° 15㎛ A B B Example 11 25℃ 200℃ 15° 20㎛ A B B Example 12 25℃ 200℃ 30° 25㎛ A A A Comparative Example 5 200℃ 200℃ 0° 15㎛ B C D Comparative Example 6 25℃ 200℃ 0° 10㎛ C C D

In Tables 1 and 2, in Examples 1 to 12, as described in the above-described embodiment, the support roller 38 is disposed on the upstream side of the knurling roller 36 (lapping angle θ1 is 0° A larger knurling device 34 was used. On the other hand, in Comparative Examples 1 to 6, a conventional knurling apparatus in which the wrapping angle θ1 was set to 0° was used.

In addition, in all Examples and Comparative Examples, a cellulose triacetate film was used as a polymer film, and knurling was applied to the film, and the state of the film and film roll was evaluated after winding up. In addition, the transport speed (winding speed) of the film was set to 100 m/min, and the load (nipping pressure) at the time of applying knurling was set to 30 kgf. However, the angle θ2 was set to 0°.

In Table 1 (Examples 1 to 6, Comparative Examples 1 to 4), knurling was applied to both surfaces 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 Knurling was applied to one side of the 40 µm film. However, the temperature and lapping angle (θ1) of the support roller or knurling roller in each of the Examples and Comparative Examples are as shown in Tables 1 and 2.

In Table 1, for Examples 1 to 6 and Comparative Examples 1 to 4, five items of knurling thickness, cracks, settlement rates, flaws, and comprehensive evaluation were evaluated. However, "" indicates that the film is torn and winding must be stopped, and is not subject to evaluation.

The knurling thickness was measured using a thickness measuring instrument (IDC-112) manufactured by Mitutoyo Corporation, and the difference between the apex portion of the convex portion of the knurling and the portion not provided with the knurling was measured, and this was used as the knurling thickness. However, it is preferable that the knurling thickness is thick.

As for the crack, the number of cracks per 500 mm of knurling was observed visually with a 5-fold loupe. When no cracks were found, it was set to “A”, when there were less than 10 cracks, “B”, and when there were more than 10 cracks, it was set to “C”. However, the fewer cracks, that is, the more preferable it goes from "C" to "A".

The settling rate represents the reduction rate of the knurling thickness when a tension of 100 N/m (100 N per 1 m length) is applied to a roller of φ 100 mm in a dry environment of 120° C. for 1 minute. However, it is preferable that the settling rate is small.

The scratches observed visually the film after conveying and winding up 500 rollers at 80 N/m. It was set to “A” when the scratch could not be confirmed, “B” when there was a scratch but less than 1 mm in length, and “C” when there was a scratch of 1 mm or more in length. However, the smaller the scratch, that is, the more preferable it goes from "C" to "A".

Comprehensive evaluation is a comprehensive evaluation of each evaluation item (in the case of Table 1, four items of knurling thickness, cracks, settling rate, and scratches), and if it can be judged that there is no problem as a product, the order of “ A” to “C”. On the other hand, when there is a problem as a product and there is a need for improvement, it was set as "D".

As shown in Table 1, as a result of comparing Examples 1 to 6 and Comparative Examples 1 to 4 in which knurling was applied while changing conditions for a film having a thickness of 60 μm, Examples 1 to 6 were compared to Comparative Examples 1 to 4 , It turned out that evaluation was high in the whole of knurling thickness, a crack, a settlement rate, and a flaw, and the comprehensive evaluation was also favorable. In addition, it was found that the larger the lapping angle θ1, the thicker the knurling thickness and better knurling with a small settling rate can be provided.

In addition, in Table 1, it was confirmed that the handling of the film can be improved by the present invention. That is, in the evaluation of scratches, in Examples 1 to 6, the evaluation was high and the problem of slipping of the conveying roller could be prevented, and in Comparative Examples 1 to 4, the evaluation was low, and it was found that the conveying roller slipped.

Subsequently, in Table 2, for Examples 7 to 12 and Comparative Examples 5 and 6, four items of knurling thickness, cracks, changes with time, and comprehensive evaluation were evaluated. However, the knurling thickness, cracking, and overall evaluation were evaluated according to the same evaluation criteria as in Table 1, so the description is omitted.

As for the change with time, the wound film roll was stored for 2 weeks in an environment of 23° C. and 50% humidity, and then the deformation of the film roll was visually observed. "A" if there was no deformation, "B" if there is no deformation, "C" if there is a slight deformation but no problem as a product, if the deformation is large and the film roll has deformation marks It was set to "D". However, the change over time is more preferable from the smaller one, that is, from “D” to “A”.

As shown in Table 2, as a result of comparing Examples 7 to 12 and Comparative Examples 5 and 6 in which knurling was applied while changing conditions for a film having a thickness of 40 μm, Examples 7 to 12 were compared to Comparative Examples 5 and 6. It turned out that the knurling thickness was thick, and there was no crack, and the comprehensive evaluation was good. However, it was found that the larger the lapping angle θ1 and the higher the temperature of the knurling roller, the thicker the knurling thickness, while the change over time also increased.

In addition, from Table 2, it was confirmed that the present invention could prevent misalignment of the film roll. That is, in the evaluation of changes over time, in Examples 7 to 12, the evaluation was high, and after the film roll became a film roll, the deviation between the overlapping films was suppressed, and the deformation of the film roll was suppressed. It was found that the film roll was deformed due to the occurrence of a shift between the overlapping films after being formed.

In addition, from Tables 1 and 2, it was confirmed that the present invention is effective not only for the film having a relatively thick thickness of 60 µm, but also for the film having a relatively thin thickness of 40 µm. In addition, it was confirmed that the present invention was effective even when the conveying speed of the film was set at a high speed of 100 m/min.

As described above, since the effectiveness of the present invention was confirmed in the case of imparting knurling to the cellulose triacetate film, next, the effectiveness of the present invention in the case of providing knurling to the polyethylene terephthalate film (PET film) Was verified. Table 3 shows the results.

Roller temperature Wrapping angle evaluation Knurling roller Support roller Knurling thickness crack Settlement rate scratch TAC 1 200℃ 200℃ 15° 60㎛ A 20% A PET 1 200℃ 200℃ 0° 20㎛ A 30% B PET 2 200℃ 200℃ 5° 60㎛ A 10% A PET 3 200℃ 200℃ 15° 100㎛ A 10% A PET 4 150℃ 150℃ 15° 60㎛ A 20% A

In Table 3, the effectiveness of the present invention was verified using TAC1 to which knurling was applied to the cellulose triacetate film, and PET1 to PET to which knurled to the PET film was applied. However, conditions at the time of granting nulling are as shown in the table, and the evaluation is also the same as in Tables 1 and 2 above, and thus descriptions thereof will be omitted.

As shown in Table 3, compared to PET1 with a wrapping angle of 0°, PET2 to 4 with a wrapping angle greater than 0° have better evaluation, and the effectiveness of applying the present invention to a PET film was confirmed.

In addition, in the case of the cellulose triacetate film and the PET film, if the conditions are the same, the PET film can provide good knurling (refer to the results of TAC1 and PET3), but the case of implementing the present invention for the cellulose triacetate film and the PET film In the case where the present invention was not carried out, it was found that good knurling can be imparted to the cellulose triacetate film when the present invention was carried out (refer to the results of TAC1 and PET1). That is, even if it is a cellulose triacetate film which is difficult to impart better knurling than a PET film, it has been found that by implementing the present invention, better knurling can be provided than a PET film without the present invention.

The reason that it is difficult for the cellulose triacetate film to give better knurling than the PET film is that the cellulose triacetate film has high mechanical strength but low breaking strength (weak), and it is difficult to deform when applying force and is easily cracked. It is mentioned that if it is not sufficiently heated to, it will crack before the required amount of deformation (knurled thickness) is reached. On the other hand, TAC1, which implemented the present invention, can provide better knurling than PET1, which does not implement the present invention, so it turned out that it is sufficiently heated to the inside of the film. As described above, according to the present invention, it is particularly effective to implement the present invention for a cellulose triacetate film that is difficult to deform and easily cracked because it is sufficiently heated to the inside of the film.

In this way, since the effectiveness of the present invention could be confirmed regardless of the type of film, the lapping angle was kept constant, and the temperature of the knurling roller or the support roller was changed to verify the optimum temperature of the knurling roller or the support roller. I did. Table 4 shows the results.

Roller temperature Wrapping angle
evaluation Knurling roller Support roller Knurling thickness crack Settlement rate scratch TAC 2 100℃ 100℃ 15° 3 3 3 3 TAC 3 150℃ 150℃ 15° 2 3 2 2 TAC 4 180℃ 180℃ 15° One One One One TAC 5 200℃ 200℃ 15° One One One One TAC 6 300℃ 300℃ 15° One One One One TAC 7 340℃ 340℃ 15° One 3 One One

In Table 4, the optimum temperature of the knurling roller or the support roller was verified using TAC2 to 7 provided with knurling for the cellulose triacetate film. Conditions at the time of imparting nulling are as shown in the table. However, it has already been demonstrated that the present invention is effective regardless of the temperature of the knurling roller or the support roller as described above (see Tables 1 to 3). In other words, in Table 4, even if an evaluation was made as to whether or not there was a quality problem, all passed (a level without quality problem), and the effect of the difference in temperature of the knurling roller or the support roller on knurling can be seen. none. For this reason, in Table 4, the range without quality problems was further divided into three stages, and evaluations of "1" to "3" were made in good order.

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 quality of the knurling improved as the temperature increased until the temperature thereof reached 180°C. Further, it was found that when the temperature of the knurling roller and the support roller was lowered from 340°C, the quality of the knurling improved as the temperature decreased until the temperature reached 300°C. In addition, it was found that the knurling quality was maintained in a good state when the temperature of the knurling roller and the support roller was 180°C to 300°C. From these, it was found that the temperature of the knurling roller and the support roller in the range of 180°C to 300°C is an appropriate range in which the film is sufficiently heated to the inside and not excessively heated.

Claims (10)

A knurling device that imparts knurling to a belt-shaped web being conveyed in the longitudinal direction,
A first roller and a second roller for holding the web from both sides;
A protrusion formed on an outer periphery of at least one of the first roller and the second roller; And
A first heater heating the first roller;
And,
The first roller is disposed upstream of the conveying direction of the web than the second roller so that the web passes between the first roller and the second roller after wrapping the outer circumference of the first roller,
The knurling is imparted by pressing the protrusion to the web by a pinch between the first roller and the second roller,
The protrusion is formed on the outer periphery of the first roller,
The wrapping angle at which the web wraps the outer circumference of the first roller is 5° or more and 30° or less.
Knurling device. The method of claim 1,
Heating the web to a temperature equal to or higher than the glass transition point and lower than the melting point by the heater
Knurling device. The method according to claim 1 or 2,
The heater, by generating a magnetic field change in the vicinity of the first roller, induction heating the first roller
Knurling device. The method according to claim 1 or 2,
Having a second heater for heating the second roller
Knurling device. delete The method according to claim 1 or 2,
The first roller and the second roller are respectively installed on one side and the other side in the width direction of the web, and the knurling is applied to both sides in the width direction of the web.
Knurling device. The method of claim 6,
The first roller and the second roller have a rotation shaft inclined with respect to the width direction so that the side portion of the web is pulled outward in the width direction by rotation.
Knurling device. The method of claim 7,
The rotating shaft is inclined in a range of 0.1° or more and 1.0° or less with respect to the width direction.
Knurling device. As a knurling method for applying knurling to a belt-shaped web being conveyed in the longitudinal direction,
Heating the web with a first roller; And
A step of clamping the web after wrapping the first roller by the first roller and the second roller to impart the knurling;
And,
The web is heated by wrapping and conveying the outer periphery of the first roller having a heater,
A protrusion is formed on an outer circumference of at least one of the first roller and the second roller, the protrusion is formed on an outer circumference of the first roller, and the knurling is provided by pressing the protrusion to the web,
The wrapping angle at which the web wraps the outer circumference of the first roller is 5° or more and 30° or less.
Knurling method. Heating the web with a first roller;
A step of applying knurling by holding the web after wrapping the first roller by the first roller and the second roller; And
Winding the web to which the knurling has been applied;
And,
The web is heated by wrapping and conveying the outer periphery of the first roller having a heater,
A protrusion is formed on an outer circumference of at least one of the first roller and the second roller, the protrusion is formed on an outer circumference of the first roller, and the knurling is applied to the web by pressing the protrusion,
The wrapping angle at which the web wraps the outer circumference of the first roller is 5° or more and 30° or less.
Web roll manufacturing method.

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