TWI600517B - Device and method for controlling position of belt edge in solution casting apparatus - Google Patents

Description

Belt edge position control device and method for solution film making equipment

The present invention relates to a belt edge position control device and method for a solution film forming apparatus.

As a representative manufacturing method of the elongated optical film, there is a continuous method of forming a solution film. It is known that a continuous solution method for forming a solution is to cast a solution (dope) in which a polymer is dissolved in a solvent on a running casting support, and peeling the cast film from the casting support and drying it. A method of making a film. The cast film is a dope which is formed into a film by casting.

The casting support has a metal belt or a drum. When it is a roller, the distance from the position where the dope is casted to the position where the cast film is peeled off becomes shorter than the tape. Therefore, it is disadvantageous when drying is such that the cast film has self-supportability to the extent that it can be peeled off from the support. Therefore, a belt type capable of supporting a cast film at a long distance is widely used.

However, the width of the film that can be manufactured is limited to the width of the tape. In order to make a wider film, a wider belt is required. However, the current situation is that only belts having a width of up to about 2 m can be obtained due to manufacturing technical problems of the belt.

In Japanese Laid-Open Patent Publication No. Hei 6-297486, the flaw in the film manufacturing apparatus is controlled as follows. First, when the endless belt (belt) is displaced from the position of the standard traveling path to the right side, the positional deviation is sensed by the first sensing means. The first sensing means outputs a right correction command signal when the positional deviation is detected, and the right bearing member is fixed by the right side expansion means. in In this state, the left bearing member is maintained in a free state, and therefore the rotating shaft of the rotating pulley (rotary drum) is tilted by the tension from the belt causing the positional deviation. The belt is moved toward the side of the smaller tension by the inclination, and the positional deviation of the belt is corrected. By the same token, when the belt is displaced from the standard traveling path to the left side, the positional deviation is also corrected by sensing the positional deviation by the second sensing means and performing the same action.

In Japanese Laid-Open Patent Publication No. 2002-254452, the first conveyor position detecting means is provided in the vicinity of the first drum holding the endless belt, and the second conveyor position detecting means is provided in the vicinity of the second drum. The first conveyor position detecting means and the second conveyor position detecting means detect the position of the belt edge, respectively. In Japanese Laid-Open Patent Publication No. 2002-254452, the conveyor position adjustment mechanism is controlled in accordance with the difference between the position detection information and the reference position of each of the detection means. In the belt position adjusting mechanism, the one end portion of the second drum is displaced by the cylinder to tilt the shaft of the drum, and the sputum is suppressed in the same manner as in Japanese Patent Laid-Open No. Hei 6-297486. In the Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. No. 2002-254452, the one end of the shaft of the drum is displaced to tilt the shaft, and the belt is moved by the tension of the belt. To correct the positional deviation.

However, since there is no requirement for a wide band in the related art, a volume of about 50 mm is allowed in the width direction of the belt, for example, a bandwidth of 2 m. Therefore, it is also possible to cope with the 蜿蜒 control method as described above. However, if the non-casting region is reduced in accordance with the requirement of the widening width, for example, when the bandwidth is 2 m, it is necessary to suppress the amount of enthalpy to about 2 mm. Therefore, for example, Japanese Patent Publication No. Hei 6-297486, Japanese Patent Publication No. 2002-254452 In the method of explaining the positional deviation of the correction tape in the publication, there is a problem that the positional deviation cannot be corrected quickly and accurately, and the request for widening cannot be performed.

Further, in order to stabilize the flow of the liquid from the casting die to the belt, the pressure vessel is provided with a decompression chamber having a negative internal pressure on the upstream side in the belt traveling direction of the casting die. In order to constantly maintain the negative pressure in the decompression chamber, it is necessary to constantly maintain the gap between the decompression chamber and the belt. Therefore, if the amount of the belt is increased, the side edge of the belt is sometimes located in the decompression chamber. At this time, there is a problem that a gap of a thickness of the belt is generated in the side edge portion of the decompression chamber, and a sudden change in pressure is caused to cause the bead to become unstable.

Further, in the solution film forming apparatus, unevenness in thickness (hereinafter referred to as thickness unevenness) or unevenness in surface characteristics (hereinafter referred to as surface property unevenness) may occur in the film by using the tape for a long period of time. As a result of intensive research, it was found that the thickness unevenness was caused by the use of the belt for a long time, especially by the stress caused by the flaw on the drum. That is, when the belt is twisted, the belt is slidably moved toward the rotation axis of the drum, for example, on the circumferential surface of the drum. By moving the cylinder circumferential surface in the direction of the rotation axis of the drum, stress is applied to the belt, and a long stripe-like peak is generated mainly in the traveling direction. The peak is the height unevenness of the belt surface, and the peak of the belt surface is equivalent to the thickness unevenness on the belt. It was judged that the peak of such a belt surface or the thickness unevenness of the belt was transferred to the cast film on the belt, and the thickness of the film was uneven and the surface characteristics were uneven. Therefore, in order to reduce the stress on the belt, it is necessary to effectively suppress the flaw of the belt.

However, in the conventional control, there is even an accurate Control, when the distance between the rollers is, for example, up to several tens of meters or so, the responsiveness is also lowered, and problems such as good precision control cannot be performed. The reason is that, as shown in Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. 2002-254452, in the conventional helium control, the rotation axis of the freely rotating drum located on the opposite side of the driving drum is changed. The angle of inclination, thereby suppressing the enthalpy of the belt at the casting position. Moreover, in the conventional method, it is necessary to displace a few tons of the drum for the cockroach control, and it is difficult to smoothly rotate the bearing due to the influence of the friction. Further, there is a problem that the mechanical loss due to the influence of friction or the like or the deflection of the driving member by the displacement of the bearing, etc., causes a decrease in the accuracy of the control.

An object of the present invention is to provide an edge position control device and method for a solution film forming apparatus which can easily respond to a widening of a film and which can perform flaw control with high precision.

The belt edge position control device of the present invention is a belt edge position control device for a solution film forming apparatus. The solution film forming apparatus peels off the cast film formed on the belt from the belt and dries it as a film. The endless belt runs around the first roller and the second roller. The cast film is formed by casting a dope in which a polymer is dissolved in a solvent from a casting die in a belt traveling in the first direction. The first direction is a direction from the first roller toward the second roller. The belt edge position control device includes a first roller belt edge position sensor, a steering roller, a steering roller tilt mechanism, and a belt edge position controller. The first roller belt edge position sensor detects the position of the tape edge in the second direction on the first roller. Second direction The width direction of the belt. The first roller belt edge position sensor outputs the detection result as an edge position signal. The steering roller contacts the inner circumferential surface of the lower belt between the first roller and the second roller. The steering roller tilting mechanism displaces the steering roller and tilts the lower side belt in the second direction. The edge position controller controls the tilt angle of the steering roller according to the edge position signal of the first roller belt edge position sensor. The edge position controller controls the tilt angle of the steering roller to suppress the change in the edge position.

The steering roller is disposed near the belt inlet of the first drum, and the steering roller tilting mechanism preferably has a displacement portion and a pair of roller bearings. The pair of roller bearings are rotatably held at both ends of the steering roller. The displacement portion displaces each of the pair of roller bearings in a direction intersecting the inner peripheral surface of the lower belt. The steering roller tilting mechanism has a lateral displacement portion. The lateral displacement portion displaces each of the roller bearings in a direction parallel to the inner circumferential surface of the lower belt.

The steering roller is disposed near the belt inlet of the first roller, and the steering roller tilting mechanism preferably has a lateral displacement portion and a pair of roller bearings. The pair of roller bearings are rotatably held at both ends of the steering roller. The lateral displacement portion displaces each of the pair of roller bearings in a direction parallel to the inner circumferential surface of the lower belt, in a state where the steering roller is brought into contact with the belt.

The belt edge position controller determines the moving speed of the belt edge in the second direction according to the edge position signal from the first roller belt edge position sensor, and controls the steering roller tilting mechanism according to the moving speed of the belt and the traveling speed of the belt. The steering roller is inclined in a direction to reduce the moving speed.

The belt edge position control device is further preferably the following (1) or (2).

(1) It has a pair of roller bearings, displacement mechanism, tension sensor and tension controller. One pair of roller bearings rotatably support both ends of the shaft of the second roller. The displacement mechanism displaces the pair of roller bearings in the first direction. The tension sensor detects the tension of the belt. The tension sensor outputs the detected tension as a tension signal. The tension controller operates the displacement mechanism and maintains the tension according to the tension signal of the tension sensor. The tension sensor is disposed at an intermediate position between the first roller and the second roller, and the tension is preferably detected by the amount of droop of the lower tape.

(2) A pair of roller bearings, a pair of displacement mechanisms, a pair of second roller position sensors, a second roller belt edge position sensor, a pair of tension sensors, and a tension controller. One pair of roller bearings rotatably support both ends of the shaft of the second roller. The pair of displacement mechanisms respectively displace the pair of roller bearings in the first direction. A pair of second roller position sensors detect the position of each of the roller bearings in the first direction. The second roller belt edge position sensor detects the position of the tape edge in the second direction on the second roller. A pair of tension sensors detect the tension of the belt. A pair of tension sensors are respectively disposed between a pair of roller bearings and a pair of displacement mechanisms. A pair of tension sensors respectively output the detected tension as a tension signal. The tension controller constantly maintains the tension of the belt according to the tension signal of the tension sensor. The tension controller constantly maintains the tension of the belt while outputting the bearing position correction signal to the pair of displacement mechanisms. The bearing position correction signal is a signal for suppressing a positional change of the belt edge on the second roller.

The belt edge position control method of the present invention is a belt edge position control method of a solution film forming apparatus. The solution film forming apparatus peels off the cast film formed on the belt from the belt and dries it as a film. The endless belt is hung around the first roller Traveling with the second roller. The cast film is formed by casting a dope in which a polymer is dissolved in a solvent from a casting die in a belt traveling in the first direction. The first direction is a direction from the first roller toward the second roller. The belt edge position control method has an edge position detecting step and a tilting step. The edge position detecting step detects the position of the tape edge in the second direction on the first roller. The second direction is the width direction of the belt. The tilting step causes the lower side belt to incline in the second direction in the direction in which the position of the edge is suppressed. The signal depending on the detection result detected in the edge position detecting step is tilted and performed by the steering roller. The steering roller contacts the inner circumferential surface of the lower belt between the first roller and the second roller.

It is preferable that one pair of roller bearings rotatably support both end portions of the steering roller disposed near the inlet of the first roller. It is preferable that the pair of roller bearings are displaced in the direction intersecting the belt surface by the displacement portion, and the lower belt is inclined in the second direction.

The displacement portion preferably displaces each of the pair of roller bearings in a direction parallel to the inner peripheral surface of the lower belt.

It is preferable that one pair of roller bearings rotatably support both end portions of the steering roller disposed near the inlet of the first roller. In a state where the steering roller is brought into contact with the belt, it is preferable that the pair of roller bearings are displaced in a direction parallel to the belt surface by the displacement portion, and the lower belt is inclined in the second direction.

The moving speed of the edge in the second direction is obtained from the edge position of the first roller belt, and it is preferable to incline the steering roller in the direction of decreasing the moving speed in accordance with the edge moving speed and the traveling speed of the belt.

It is preferable that both ends of the shaft of the second roller are rotatably supported by the roller bearing. The tension of the belt is detected by a tension sensor and used as a tension signal. The output is preferably based on the tension signal of the tension sensor and the displacement of the roller bearing in the first direction by the displacement mechanism and the constant tension. It is more preferable to detect the tension by the amount of drape of the lower side belt at the intermediate position between the first roller and the second roller.

The belt edge position control method further preferably includes a supporting step, a second drum position detecting step, a displacement step, a second drum belt edge position detecting step, and a tension controlling step. In the supporting step, both ends of the shaft of the second roller are rotatably supported by the pair of roller bearings. The second drum position detecting step detects the position of the pair of roller bearings in the first direction by the pair of second drum position sensors. In the displacement step, each pair of roller bearings is displaced in the first direction by a pair of displacement mechanisms. The second roller belt edge position detecting step detects the position of the tape edge in the second direction on the second roller by the second roller belt edge position sensor. The tension control step outputs a bearing position correction signal to the pair of displacement mechanisms while the tension of the belt is constantly maintained by the tension controller. The tension of the belt is kept constant by the tension signal of the pair of tension sensors. A pair of tension sensors are respectively disposed between a pair of roller bearings and a pair of displacement mechanisms. The bearing position correction signal is a signal for suppressing a change in the position of the belt edge on the second roller.

According to the present invention, it is possible to quickly and accurately suppress the flaws on the first roller. Therefore, the position control of the belt can be performed with high precision, and for example, the belt having a width of 2000 mm can be suppressed to have an amplitude of about 2 to 3 mm. Thereby, the amount of movement of the belt in the direction of the drum axis is reduced, and the width of the non-casting region between the both side edges of the belt and the both side edges of the casting film can be reduced, and the wide elongated shape can be efficiently manufactured. film. And can be fast and precise The enthalpy of the belt is well suppressed, and the amount of displacement of the belt on the drum during the control is also small. Therefore, it is possible to suppress the occurrence of a streak-like peak on the belt by the long-term change of the flaw caused by the belt. Thereby, it is possible to extend the life of the belt and to remove the thickness unevenness of the film to be formed.

As shown in FIG. 1, the solution film forming apparatus 10 is connected in series from the upstream side to the casting apparatus 11, the first tenter 12, the roll drying apparatus 13, the second tenter 14, the slitter 15, and the winding device 16 in this order. And constitute.

The casting device 11 includes a belt 23 surrounding the first and second rolls 21 and 22, a casting die 24, a duct 25, a decompression chamber 26, a peeling roller 27, and a belt edge position control device (hereinafter, referred to as BEP control). Device) 28. The BEP control device 28 controls the position (BEP) of the side edge (edge) in the width direction of the belt 23, and the details will be described later using other drawings. The belt 23 is made of metal and is an annular casting support formed into a ring shape. The belt 23 is wound around the circumferential surfaces of the first drum 21 and the second drum 22. The belt 23 on the upper side of each of the rollers 21, 22 is referred to as an upper belt 23A, and the belt 23 on the lower side is referred to as a lower belt 23B. The first roller 21 is rotationally driven by a drum rotation motor (refer to FIG. 2) 29, whereby the belt 23 travels in the first direction indicated by the arrow A.

The casting die 24 is disposed above the first roller 21. The casting die 24 continuously flows out of the dope 30 against the traveling belt 23. Thereby, the casting film 31 is formed on the belt 23. The dope 30 is produced, for example, by dissolving a cellulose halide in a solvent, and is supplied to a casting die 24 on a dope production line (not shown).

The decompression chamber 26 is provided upstream of the traveling direction of the belt 23 with respect to the liquid droplets 34 from the casting die 24. The decompression chamber 26 attracts the upstream of the liquid bead 34 The atmosphere in the side zone decompresses the upstream side zone of the bead 34 to reduce the vibration of the bead 34.

In order to increase the manufacturing speed, the casting film 31 facing the peeling roller 27 is heated by the second roller 22 and the belt 23. Further, the belt 23 is cooled by the first roller 21 at the casting position so as not to excessively raise the temperature of the belt 23. Therefore, each of the rollers 21 and 22 has a temperature adjustment device (not shown).

A plurality of conduits 25 are arranged along the path of the belt 23. Each of the ducts 25 is connected to a warm air controller (not shown) having a blower, and blows dry air from the outflow port. The temperature controller independently controls the temperature, humidity and flow of the dry wind. The casting film 31 is dried by controlling the temperature and flow rate of the dry air and adjusting the temperature of the casting film 31 based on the temperature control of the temperature adjusting means of the first and second rolls 21 and 22 themselves. Further, the cast film 31 is cured to such an extent that it can be transported by the first tenter 12 to impart self-supportability.

A peeling roller 27 is provided on the upstream side in the traveling direction of the casting die 24 of the first drum 21. When the dried casting film 31 in a state containing a solvent is peeled off from the belt 23, the peeling roller 27 supports the casting film 31. The peeled cast film 31, that is, the film 32 is guided to the first tenter 12.

In the first tenter 12, the both sides of the film 32 are gripped by the clip 33, and the film 32 is conveyed to the second direction (film width direction) indicated by the arrow B to expand the width of the film 32. The pre-heating zone, the stretching zone, and the relaxation zone are sequentially formed on the first tenter 12 from the upstream side. In addition, the relaxation zone is set as needed.

The first tenter 12 has a pair of guide rails and a chain (none of which are shown). The guide rails are disposed at predetermined intervals on both sides of the conveying path of the film 32. The The rail spacing is constant in the preheating zone, gradually widening toward the downstream in the stretching zone, constant in the relaxation zone or gradually narrowing toward the downstream. Clips 33 are mounted on the chain at constant intervals.

The preheating zone, the stretching zone, and the relaxation zone serve as space formers by sending dry air from the duct 35, and there is no clear boundary between the zones. Dry air adjusted to a predetermined temperature or humidity is sent from the slit of the duct 35 toward the film 32.

In the roll drying device 13, the film 32 is wound around a plurality of rolls 36 and conveyed. The temperature or humidity of the internal atmosphere of the roll drying device 13 is adjusted by a thermostat (not shown), and the solvent evaporates from the film 32 during the conveyance of the film 32.

The second tenter 14 has the same configuration as the first tenter 12, and has a clip 38 and a duct 39. The second tenter 14 holds and stretches the film 32 by the clip 38. The film 32 having the desired optical characteristics is formed by the stretching. The obtained film 32 can be used, for example, as a retardation film for a liquid crystal display. Further, depending on the optical characteristics of the film 32, it is not necessary to use the second tenter 14.

The slitter 15 cuts out the side portion including the holding marks of the respective clips 33, 38 based on the first tenter 12 or the second tenter 14. The film 32 of the cut side portion is wound into a roll shape by the winding device 16.

As shown in FIG. 2 and FIG. 3, both ends of the drum rotating shaft 21A of the first drum 21 are rotatably supported by a bearing 17. Further, a drum rotation motor 29 is connected to one end portion of the drum rotating shaft 21A. A TG (speed sensor) 18 is connected to the drum rotation motor 29, and the TG 18 detects the number of revolutions of the first drum 21. The drum rotation motor 29 is connected to the system controller via the driver 19. 20. Moreover, the TG 18 is also coupled to the system controller 20. The system controller 20 controls the rotation of the drum rotation motor 29 so that the belt 23 rotates at a constant speed. Further, the system controller 20 changes the traveling speed or drying temperature of the belt 23 in accordance with the film forming conditions.

As shown in FIGS. 3 and 4, the BEP control device 28 has a first BEP control unit 28A and a second BEP control unit 28B.

The first BEP control unit 28A includes a steering roller 40, a first roller belt edge position sensor (hereinafter referred to as a first roller BEP sensor) 41, a steering roller tilt mechanism 42, and a BEP controller 43. The first roller belt edge position sensor (hereinafter referred to as a first roller BEP sensor) 41 detects the edge position of one of the belts 23 in the second direction B in the tape width direction, and the detection result is referred to as 1 with edge signal (hereinafter referred to as 1BEP signal) output. The BEP controller 43 tilts the steering roller 40 in the second direction B (refer to FIG. 2) in the vertical plane in accordance with the first BEP signal of the first roller BEP sensor 41, thereby constantly maintaining the BEP.

As shown in FIGS. 2 and 3, the second BEP control unit 28B has displacement mechanisms 45R and 45L, bearing position sensors 46R and 46L of the second roller 22, tension sensors 47R and 47L, and a second roller belt edge position sense. A detector (hereinafter referred to as a second roller BEP sensor) 48 and a tension controller 51.

As shown in FIG. 2, the tension controller 51 inclines the center line CL2 of the second drum 22 at an inclination angle θ2 with respect to the reference line BL2 in the horizontal plane. Thereby, the difference in tension between the left and right sides (both sides in the second direction) of the belt 23 is eliminated, and the flaw of the belt 23 on the second drum 22 due to the tension difference is suppressed, and the BEP on the second drum 22 is constantly held. In addition, in the present embodiment, In the case where it is necessary to identify the left and right members, "R" is added to the symbol of each member on the right side, and "L" is added to the symbol of each member on the left side, with reference to the first direction A.

As shown in FIG. 4, the steering roller 40 is rotated in contact with the inner peripheral surface 23C of the lower side belt 23B. The steering roller 40 is made of metal, and a surface finisher such as a rubber lining can be used as needed. The steering roller tilting mechanism 42 has roller bearings 40BR, 40BL and displacement portions 55R, 55L that displace the two roller bearings 40BR, 40BL. The roller bearing 40BR is attached to one end of the shaft of the steering roller 40, and rotatably supports the steering roller 40. The roller bearing 40BL is attached to the other end of the shaft of the steering roller 40, and rotatably supports the steering roller 40. Thus, both ends of the steering roller 40 are supported by the pair of roller bearings 40BR, 40BL. The displacement portion 55R displaces the roller bearing 40BR in the vertical direction intersecting the inner peripheral surface 23C of the lower belt 23B. The displacement portion 55L displaces the roller bearing 40BL in the vertical direction intersecting the inner peripheral surface 23C of the lower belt 23B. In this manner, the roller bearings 40BR and 40BL are displaced by the displacement portions 55R and 55L, respectively. Thereby, the center line CL1 of the steering roller 40 is inclined with respect to the reference line BL1 of the second direction B by the inclination angle θ1. By the inclination of the steering roller 40, the inner peripheral surface 23C contacts the lower side belt 23B of the steering roller 40 to move on the steering roller 40 in accordance with the inclination angle θ1 of the steering roller 40. By this movement, the flaw of the lower side belt 23B on the first drum 21 can be suppressed.

The BEP controller 43 operates the displacement portions 55R and 55L in accordance with the BEP signal from the first roller BEP sensor 41 to maintain the BEP in the first roller BEP sensor 41 at a constant position, thereby suppressing the generation of flaws. To this end, a belt travel speed command signal is input from the system controller 20 to the BEP controller 43. No. and BEP position command signal.

The BEP controller 43 determines the moving speed Ve1 of the belt edge (BE) in the second direction B on the first drum 21 based on the BEP signal from the first drum BEP sensor 41. Then, the target tilt angle of the steering roller 40 is obtained based on the BE moving speed Ve1 and the speed command signal from the system controller 20 so that the BE moving speed Ve1 becomes "0" and becomes the target BEP. Then, the displacement amount of each of the displacement portions 55R and 55L is calculated based on the obtained target inclination angle, and a displacement control signal is sent to each of the displacement portions 55R and 55L so as to become the displacement amount. The displacement amounts are adjusted by the displacement control signals on the displacement portions 55R and 55L. Therefore, according to the current BEP, the correction of the target BEP is performed. Further, the relationship between the BE moving speed Ve1, the belt traveling speed VB, and the tilt angle θ1 is obtained by testing in advance on a real machine, and their relationship is stored, for example, as a lookup table data.

For example, as shown in FIG. 5, when the BEP signal of the first roller BEP sensor 41 detects that the lower side belt 23B has started to move to the right side on the first roller 21, the displacement portions 55R and 55L are lowered in order to correct this. The roller bearing 40BL, the roller bearing 40BR, tilts the steering roller 40. Thereby, the lower side belt 23B is displaced to the left side on the steering roller 40, and the BEP on the first drum 21 is quickly positioned at the target BEP. Therefore, the flaw of the belt 23 on the first roller 21 is quickly and effectively suppressed. Further, when the BE moving speed Ve1 is high, the inclination angle θ1 of the steering roller 40 is increased, and when the BE moving speed Ve1 is low, the inclination angle θ1 is decreased.

In this manner, the BEP is corrected by the steering roller 40 in the vicinity of the first roller 21 that is closer to the casting position. The second roller 22 is made with a casting device as is conventional When the rotating shaft 22A is inclined to suppress the belt, the flaw can be suppressed quickly and easily. When the rotation axis 22A of the second drum 22 is inclined to suppress the ridge of the belt 23, the distance between the first and second rollers 21 and 22 is, for example, several tens of meters long, and mechanical loss (mechanical The loss or the deflection or the like only becomes larger than the amount by which the belt 23 becomes longer. When the load applied to the bearing of the second drum 22 is, for example, about 5 tons, and the bearing is rotated by the displacement mechanisms 45R and 45L, the friction becomes high and it is not easy to rotate. Further, due to the occurrence of mechanical loss, the amount of deflection, and the like, the reproducibility is lowered, the accuracy of the suppression of ruthenium is lowered, and the ruthenium cannot be quickly suppressed. On the other hand, in the present embodiment, the cymbal of the lower belt 23B is corrected by the steering roller 40 in the vicinity of the first drum 21. Therefore, the flaw can be corrected quickly. Further, in the present embodiment, the belt 23 is tilted by the steering roller 40 on the belt inlet side of the first drum 21 to correct the flaw. Therefore, it is possible to effectively correct the flaw with a smaller force than the tilting of the rotating shaft 22A of the second drum 22 with a small amount of displacement, and it is possible to perform the weir control quickly and accurately. In addition, the belt inlet side of the first drum 21 refers to the vicinity of the upstream side of the first drum 21 in the traveling direction of the belt 23.

As shown in FIG. 2, in the second BEP control unit 28B, one end of the drum rotating shaft 22A of the second drum 22 is rotatably supported by the bearing 52R, and the other end is rotatably supported by the bearing 52L. . The bearings 52R and 52L are movably provided in the first direction A toward the first roller 21 in the horizontal plane including the respective rotation shafts 21A and 22A. Further, the bearing 52R is displaced in the first direction A by the displacement mechanism 45R, and the bearing 52L is displaced in the first direction A by the displacement mechanism 45L. So, bearing 52R, Each of the 52L is displaced in the first direction A by the displacement mechanisms 45R and 45L. Further, the displacement mechanisms 45R and 45L or the displacement portions 55R and 55L of the first BEP control unit 28A can move the respective bearings 52R, 52L, 40BR, and 40BL. For example, a person who uses a hydraulic cylinder or a rotation driver by a worm shaft or a screw rod or the like can be appropriately selected.

A right bearing position sensor 46R is mounted on the right bearing 52R, and a left bearing position sensor 46L is mounted on the left bearing 52L. The bearing position sensors 46R, 46L detect the positions of the respective bearings 52R, 52L in the first direction A. Further, instead of detecting the position of each of the bearings 52R and 52L by the bearing position sensors 46R and 46L, the displacement of the end portion of the rotation shaft 22A of the second roller 22 can be detected in the first direction A, and the detection position or detection can be detected. The method is not particularly limited.

A right side tension sensor 47R and a left side tension sensor 47L are attached between each of the bearings 52R and 52L and the displacement mechanisms 45R and 45L. The right side tension sensor 47R detects the tension of the belt 23 and outputs it as a tension signal. The left side tension sensor 47L detects the tension of the belt 23 and outputs it as a tension signal.

A second roller belt edge position sensor (hereinafter referred to as a second roller BEP sensor) 48 is provided on the second roller 22. The second roller BEP sensor 48 detects one side edge of the tape 23 in the film width direction (second direction B), for example, the left edge position, and uses the detection result as the second tape edge position signal on the second roller (below) , called the 2BEP signal) output.

The tension controller 51 is eliminated by the signals of the bearing position sensors 46R, 46L, the tension sensors 47R, 47L, and the second roller BEP sensor 48. The difference in tension between the right and left causes the displacement mechanisms 45R and 45L to operate such that the respective tensions become constant values. Therefore, the sum of the signals of the left and right tension sensors 47R, 47L is used as the belt tension, and the belt tension is constantly maintained in accordance with the tension command from the system controller 20. Further, the difference between the signals of the left and right tension sensors 47R and 47L is used as the left and right tension difference of the belt, and the left and right tension difference is controlled.

The displacement mechanisms 45R and 45L are inclined at an arbitrary inclination angle θ2 with respect to the reference line BL2 in the horizontal plane by displacement of the respective bearings 52R and 52L in the first direction A. By this inclination, the tension unevenness in the second direction B (hereinafter referred to as tension unevenness) is released, and the flaw of the belt caused by the unevenness of the tension is suppressed. Moreover, the tension (tension) of the belt 23 is also adjusted to a constant value by the individual movement of the bearings 52R, 52L based on the displacement mechanisms 45R, 45L.

The displacement amount of each of the displacement mechanisms 45R and 45L for suppressing the flaw of the belt 23 caused by the tension difference is determined in advance by a test or simulation on the actual machine, and is stored in the memory in the form of a query lookup table. In the body. Therefore, as long as the left and right tension signals and the belt traveling speed are input, the amount of displacement for suppressing the flaw caused by the tension differences is calculated. Further, each of the displacement mechanisms 45R and 45L operates to have such a displacement amount.

Further, the tension controller 51 operates the displacement mechanisms 45R, 45L in accordance with the tension command signal from the system controller 20, and performs tension control so that the tension of the belt 23 becomes a value indicated by the command signal. For example, when the belt tension is small, the displacement amount of each of the displacement mechanisms 45R, 45L is increased, and when the belt tension is large, the displacement amount of each of the displacement mechanisms 45R, 45L is reduced, thereby constantly Keep tension.

As described above, in the second BEP control unit 28B, the bearings 52R and 52L of the second roller 22 are respectively displaced to control the tension. Thereby, the tension fluctuation of the temperature distribution of the belt 23 in an unstable period is effectively suppressed. Therefore, the flaw of the belt 23 can be effectively suppressed at the start of casting or the change in the casting speed, the change in the drying temperature of the cast film, and the like.

The control of correcting the flaw of the belt 23 caused by the tension variation is particularly effective at the start of casting. At the start of the casting, unlike the stable period, since the temperature distribution in the width direction of the belt 23 is not uniform, the length of the belt 23 in the first direction is likely to locally fluctuate in the second direction due to the unevenness of the temperature distribution. The local tension fluctuations can be grasped as the main factor component by the left and right tension sensors 47R and 47L, and the flaw caused by the uneven temperature distribution of the belt 23 can be effectively eliminated. Therefore, the enthalpy control at the start of the casting is performed with good precision. Further, when the left and right tension differences are within a predetermined range, and the influence of the enthalpy due to the difference between the right and left tensions is small, the second drum rotating shaft 22A can be tilted to suppress the squeak and the control is stopped, and only the first BEP is controlled. Unit 28A suppresses enthalpy.

In the first embodiment, in addition to the tension control for constantly maintaining the belt tension by the second BEP control unit 28B, the suppression by the left-right tension difference is performed, and the first BEP control unit 28A is still unable to eliminate the flaw. Suppressed. Thereby, accurate enthalpy control can be performed. However, instead of this, by the second BEP control unit 28B, it is also possible to perform only the control of constantly maintaining the belt tension.

Moreover, in the second BEP control unit 28B, the replacement is from the left and right. The sum of the signals of the tension sensors 47R, 47L detects the belt tension or, in addition, the intermediate portion tension sensor 49 from the amount of droop based on the intermediate position of the lower side belt 23B in the belt traveling direction (refer to The signal of Figure 3) suppresses the change in tension.

At this time, in the intermediate position between the first roller 21 and the second roller 22 (hereinafter referred to as the intermediate position of the roller), the intermediate portion tension sensor 49 is provided in the vicinity of the left edge portion of the lower belt 23B. The intermediate portion tension sensor 49 determines the tension of the belt 23 by the amount of the hanging of the lower side belt 23B at the center position. When the tension between the tension and the amount of the tape 23 is increased, the amount of droop becomes small. Formula (1) represents the relationship. T is the tension of the belt (N), Ld is the distance between the centers of the drums (m), Wb is the width of the belt (mm), t is the thickness of the belt (mm), and γ is the density of the belt (kg/dm ³ ) , g is the gravitational acceleration (9.81 m/s ² ), and D is the natural overhang amount (mm) at the middle position of the drum.

T=(Ld ² .Wb.t.γ.g)/(8.D) (1)

Further, the amount of the hanging amount at the center position may be a natural hanging amount based on the weight of the belt itself, or may be a hanging amount in a state of being biased downward by a pressing roller or the like. At this time, it is calculated by adding the correction amount according to the pressing force to the person obtained by the above formula (1). The displacement amount of each of the bearings 52R, 52L is changed so that the tension signal from the intermediate portion tension sensor 49 is constant, whereby the amount of suspension can be always limited to a constant range, and the belt 23 can be held substantially constant. tension.

Further, in addition to the tension signals of the right and left tension sensors 47R, 47L, the tension signal of the intermediate portion tension sensor 49 is also input to the tension controller 51, and the tension signal of the intermediate portion tension sensor 49 can be added. No. to control the cockroach. At this time, the tension signals of the tension sensors 47R and 47L on the right and left sides and the tension signal of the intermediate portion tension sensor 49 are changed and added, whereby the enthalpy control can be performed more accurately.

Further, the belt tension can be controlled by the inclination of the steering roller 40 of the first BEP control unit 28A, instead of the tension control of the belt 23 by displacing the bearings 52R and 52L of the rotary shaft 22A of the second drum 22. At this time, the belt tension control can also be performed together with the 蜿蜒 control by the displacement amount of the 蜿蜒 suppression amount plus the displacement amount for constantly maintaining the belt tension.

In the first embodiment shown in FIGS. 2 to 4, a new casting device including the first BEP control unit 28A and the second BEP control unit 28B will be described as an example. However, by newly setting the first BEP control unit 28A with respect to the existing casting device, the same principle can also perform accurate 蜿蜒 control on the existing equipment. At this time, the existing cockroach control is stopped and only the tension control is performed, and the first BEP control unit 28A performs the cockroach control. Further, the belt position control on the second drum is also performed by the conventional cymbal control. On the basis of this, the first BEP control unit 28A can suppress the sudden enthalpy which is still generated.

As shown in FIGS. 4 and 5, in the above embodiment, the steering roller 40 uses a full roll that is in contact with the inner peripheral surface 23C of the lower side belt 23B. However, the steering roller 40 may be a plurality of rollers that are in contact with the entire width direction of the belt 23 and are spaced apart from each other in the width direction of the belt, in addition to the entire belt which is in contact with the entire width of the belt 23. Moreover, as long as it is reduced relative to the belt 23 It is only necessary to slid by the resistance, and it is not particularly limited to the roller method, and a steering guide that can tilt the belt 23 to suppress the cymbal can be used.

The steering roller tilting mechanism 42 displaces the steering roller 40 in the vertical plane perpendicular to the inner peripheral surface 23C of the lower side belt 23B, and inclines the lower side belt 23B in the second direction B. However, the displacement directions of the roller bearings 40BR and 40BL are not limited to the vertical faces, and may be displaced in any direction crossing the inner peripheral surface 23C of the lower side belt 23B.

6 and 7 show a steering roller tilting mechanism 62 according to another embodiment, which has a lateral displacement portion 60 and a longitudinal displacement portion 61. The longitudinal displacement portion 61 brings the steering roller 40 into contact with the inner peripheral surface 23C of the lower side belt 23B, and winds the lower side belt 23B around the steering roller 40 in a predetermined range. Next, the roller bearings 40BR and 40BL are displaced by the lateral displacement portion 60, and the steering roller 40 is swung in the horizontal plane. In this manner, the amount of displacement in the vertical direction and the amount of displacement in the horizontal direction of the roller bearings 40BR and 40BL are changed in accordance with the amount of enthalpy. Thereby, flaws can be effectively suppressed. Further, in FIGS. 6 and 7, the steering roller 40 and the longitudinal displacement portion 61 are collectively displaced by the lateral displacement portion 60. However, the order of connection of the respective displacement portions 60, 61 may be reversed, and when connected in the reverse order, the steering roller 40 and the lateral displacement portion 60 are uniformly displaced by the longitudinal displacement portion 61. Therefore, the longitudinal displacement amount is arbitrarily set by the longitudinal displacement portion 61 in a state where the steering roller 40 is swung in the horizontal plane by the lateral displacement portion 60. Further, the longitudinal displacement portion 61 can be omitted, and the steering roller 40 can be swung in the horizontal plane only by the lateral displacement portion 60 in a state where the steering roller 40 is maintained in contact with the lower side belt 23B at a predetermined winding angle.

Figure 8 shows a steering roller tilting mechanism 68 by having a rocker arm 65 The rocking mechanism 66 displaces the roller bearings 40BR and 40BL at arbitrary positions in the circular arc locus 67, instead of using the lateral displacement portion 60 and the longitudinal displacement portion 61. The steering roller 40 can be tilted in a desired direction by the steering roller tilting mechanism 68, and the turns of the belt 23 can be suppressed by the same action as described above.

In the above-described embodiment, the casting die 24 is provided so that the tape 23 is placed on the winding region of the first roller 21 at the casting position, but the position of the casting die 24 can be appropriately changed. For example, the casting die 24 may be provided between the two rolls 21 and 22 so that the casting position is on the belt 23 from the first drum 21 toward the second drum 22. At this time, it is preferable to arrange the casting die 24 so as to face the belt 23 from the first drum 21 toward the second drum 22, and to arrange the casting die 24 so as to face the belt 23 on the supporting roller. At this time, the first roller BEP sensor 41 may be disposed near the casting position instead of being disposed in the vicinity of the first roller 21.

The width of the belt 23 is not particularly limited. However, it is preferable to use a width Wb of 1500 mm or more and 2100 mm or less. The width of the film 32 to be produced is required to be wider. The length of the belt 23 is determined in accordance with the casting speed, drying conditions, and the like.

The concentrated liquid which is cast on the belt 23 is preferably a cellulose halide which is a concentrated liquid in which a polymer capable of forming a solution film is dissolved in a solvent. The thiol group of the cellulose halide may be only one type, or may have two or more types of fluorenyl groups. When the fluorenyl group is two or more, one of them is preferably an acetamino group. It is preferred that the ratio of the hydroxyl group of the carboxylated cellulose, that is, the degree of substitution of the thiol group, satisfies the following formulas (I) to (III). In addition, in In the following formulas (I) to (III), A and B represent the degree of substitution of a mercapto group, A is a degree of substitution of an ethylidene group, and B is a degree of substitution of a mercapto group having 3 to 22 carbon atoms.

The total substitution degree A+B of the fluorenyl group is preferably 2.20 or more and 2.90 or less, and more preferably 2.40 or more and 2.88 or less. Further, the substitution degree B of the fluorenyl group having 3 to 22 carbon atoms is more preferably 0.30 or more, and particularly preferably 0.5 or more. Among them, cellulose diacetate (DAC) is preferred as the cellulose halide.

10‧‧‧solution film making equipment

11‧‧‧casting device

12‧‧‧1st tenter

13‧‧‧Roll drying device

14‧‧‧2nd tenter

15‧‧‧ slitting machine

16‧‧‧Winding device

17‧‧‧ bearing

18‧‧‧TG (speed sensor)

19‧‧‧ Drive

20‧‧‧System Controller

21‧‧‧1st roller

21A, 22A‧‧‧Rolling axis

22‧‧‧2nd roller

23‧‧‧With

23A‧‧‧Upper side belt

23B‧‧‧Bottom belt

23C‧‧‧ Inner circumference of the lower belt

24‧‧‧casting mode

25, 35, 39‧ ‧ catheter

26‧‧‧Decompression room

27‧‧‧ peeling roller

28‧‧‧BEP control unit

28A‧‧‧1BEP Control Unit

28B‧‧‧2BEP Control Unit

29‧‧‧Roller rotary motor

30‧‧‧Liquor

31‧‧‧cast film

32‧‧‧film

33, 38‧‧‧ clip

34‧‧‧Liquid beads

36‧‧‧ Roll

40‧‧‧steering roller

40BR, 40BL‧‧‧ bearing

41‧‧‧1st roller BEP (with edge position) sensor

42, 62, 68‧‧‧ steering roller tilting mechanism

43‧‧‧BEP controller

45R, 45L‧‧‧ displacement mechanism

46R, 46L‧‧‧ bearing position sensor

47R, 47L‧‧‧ Tension Sensor

48‧‧‧2nd roller BEP sensor

49‧‧‧Intermediate tension sensor

51‧‧‧ Tension controller

52R, 52L‧‧‧ bearing

55R, 55L‧‧‧ displacement department

60‧‧‧Transverse displacement

61‧‧‧ longitudinal displacement

62,68‧‧‧steering roller tilting mechanism

65‧‧‧ rocker arm

66‧‧‧Shake mechanism

67‧‧‧Circular track

A‧‧‧1st direction

B‧‧‧2nd direction

BL1, BL2‧‧‧ baseline

CL1, CL2‧‧‧ center line

Θ1, θ2‧‧‧ tilt angle

Fig. 1 is a schematic view of a solution film forming apparatus.

Figure 2 is a block diagram of the belt edge position control device in plan view.

Fig. 3 is a block diagram similarly viewed from the side.

Fig. 4 is a block diagram similarly viewed from the front.

Fig. 5 is a front view for explaining the operation of the steering roller.

Fig. 6 is a plan view for explaining an operation of a steering roller according to another embodiment.

Figure 7 is a side view of the same.

Fig. 8 is a side view for explaining the operation of the steering roller of another embodiment.

17‧‧‧ bearing

18‧‧‧TG (speed sensor)

19‧‧‧ Drive

20‧‧‧System Controller

21‧‧‧1st roller

21A, 22A‧‧‧Rolling axis

22‧‧‧2nd roller

23‧‧‧With

23B‧‧‧Bottom belt

23C‧‧‧ Inner circumference of the lower belt

24‧‧‧casting mode

26‧‧‧Decompression room

27‧‧‧ peeling roller

28‧‧‧BEP control unit

28A‧‧‧1BEP Control Unit

28B‧‧‧2BEP Control Unit

29‧‧‧Roller rotary motor

30‧‧‧Liquor

31‧‧‧cast film

32‧‧‧film

34‧‧‧Liquid beads

40‧‧‧steering roller

41‧‧‧1st roller BEP sensor

43‧‧‧BEP controller

45L‧‧‧displacement mechanism

46L‧‧‧bearing position sensor

47L‧‧‧Tensor

48‧‧‧2nd roller BEP sensor

49‧‧‧Intermediate tension sensor

51‧‧‧ Tension controller

52L‧‧‧ bearing

55L‧‧‧ displacement department

A‧‧‧1st direction

Claims (16)

A belt edge position control device for a solution film forming apparatus, wherein the solution film forming apparatus peels off a cast film formed on a belt from the belt and dries it as a film, and the ring-shaped belt is hung around the first drum The second casting film is formed by the second roller, and the casting film is formed by casting a dope in which the polymer is dissolved in the solvent from the casting die in the belt traveling in the first direction, and the first direction is from the first In the direction of the second roller, the belt edge position control device includes a first roller belt edge position sensor that detects a position of the belt edge in the second direction on the first roller, and the second The direction is the width direction of the belt, and the first roller belt edge position sensor outputs the detection result as an edge position signal; the steering roller contacts the inside of the lower belt between the first roller and the second roller a rolling surface tilting mechanism that inclines the center line of the steering roller with respect to the reference line in the second direction, and causes the lower side belt to be along the center of the steering roller in response to the inclination of the steering roller And an edge position controller that controls an angle of inclination of the steering roller according to the edge position signal of the first roller belt edge position sensor, wherein the edge position controller prevents fluctuation of a position of the edge The aforementioned tilt angle is controlled. The edge position control device according to claim 1, wherein the steering roller is disposed near a belt inlet of the first roller, and the The steering roller tilting mechanism includes a displacement portion and a pair of roller bearings, wherein the pair of roller bearings rotatably hold both end portions of the steering roller, and the displacement portion causes the pair of roller bearings to respectively face the lower side belt The inner circumferential surface is displaced in the direction of the intersection. The belt edge position control device according to claim 2, wherein the steering roller tilting mechanism has a lateral displacement portion that causes each roller bearing to be parallel to an inner circumferential surface of the lower belt Directional displacement. The edge position control device according to claim 1, wherein the steering roller is disposed near a belt inlet of the first roller, and the steering roller tilting mechanism has a lateral displacement portion and a pair of roller bearings, and the first The roller bearing is rotatably held at both end portions of the steering roller, and the lateral displacement portion causes the pair of roller bearings to be parallel to the lower side belt, respectively, in a state where the steering roller is brought into contact with the belt The direction of the inner circumferential surface is displaced. The edge position control device according to claim 1, wherein the edge position controller determines the edge in the second direction based on the edge position signal from the first roller belt edge position sensor. In the upper moving speed, the steering roller tilting mechanism is controlled in accordance with the moving speed of the edge and the traveling speed of the belt, and the steering roller is inclined in a direction to reduce the moving speed. The belt edge position control device according to claim 1, further comprising: a pair of roller bearings rotatably supporting both end portions of the shaft of the second roller; and a displacement mechanism for the pair of roller bearings Displacement along the first direction; a tension sensor that detects the tension of the belt, the tension sensor outputs the detected tension as a tension signal; and a tension controller that shifts the displacement according to the tension signal of the tension sensor The mechanism works and the tension is constant. The edge position control device according to claim 6, wherein the tension sensor is disposed at an intermediate position between the first roller and the second roller, and the tension is detected by a hanging amount of the lower tape. The belt edge position control device according to claim 1, further comprising: a pair of roller bearings rotatably supporting both end portions of the shaft of the second roller; and a pair of displacement mechanisms to make the pair of the pair The roller bearings are respectively displaced in the first direction; one pair of second roller position sensors detects the position of each roller bearing in the first direction; and the second roller belt edge position sensor detects on the second roller a position of the edge in the second direction; a pair of tension sensors detecting the tension of the belt, the first pair of tension The sensors are respectively disposed between the pair of roller bearings and the pair of displacement mechanisms, and the pair of tension sensors respectively output the detected tension as a tension signal; and the tension controller is configured according to the tension sensor The tension signal constantly maintains the tension of the belt, and the tension controller continuously outputs the bearing position correction signal to the pair of displacement mechanisms while maintaining the tension of the belt, and the bearing position correction signal is for suppressing the aforementioned edge in the foregoing The signal of the position change on the second roller. A method for controlling a position of a belt edge of a solution film forming apparatus, wherein the solution film forming apparatus peels a cast film formed on a belt from the belt and dries it as a film, and the ring-shaped belt is hung around the first drum The second casting film is formed by the second roller, and the casting film is formed by casting a dope in which the polymer is dissolved in the solvent from the casting die in the belt traveling in the first direction, and the first direction is from the first The roller is oriented in the direction of the second roller, and the tape edge position control method includes a step of: (A) detecting a position of the tape edge in the second direction on the first roller, wherein the second direction is a width of the tape And (B) a center line of the steering roller contacting the inner circumferential surface of the lower belt between the first roller and the second roller with respect to the first direction according to a signal of the detection result detected in the step A The reference line in the two directions is inclined, and the lower side belt is moved along the center line on the steering roller in response to the inclination of the steering roller to suppress the fluctuation of the edge position. The method for controlling an edge position according to claim 9 of the patent application scope, wherein The pair of roller bearings rotatably support both end portions of the steering roller disposed near the belt inlet of the first roller, and the pair of roller bearings are respectively intersected by the surface of the belt by the displacement portion The direction is displaced, and the aforementioned lower side belt is moved along the aforementioned center line on the aforementioned steering roller. The edge position control method according to claim 10, wherein the displacement portion displaces each of the pair of roller bearings in a direction parallel to an inner circumferential surface of the lower belt. The edge position control method according to claim 9, wherein the pair of roller bearings rotatably support both end portions of the steering roller disposed in the vicinity of the belt inlet of the first roller, and In a state where the steering roller contacts the belt, the pair of roller bearings are respectively displaced in a direction parallel to a surface of the belt by a displacement portion, and the lower belt is along the center line on the steering roller mobile. The edge position control method according to claim 9, wherein the moving speed of the edge in the second direction is obtained according to the edge position of the first roller belt, and the moving speed of the edge is the same as the belt The traveling speed causes the aforementioned steering roller to tilt in a direction to reduce the aforementioned moving speed. The edge position control method according to claim 9, wherein both ends of the shaft of the second roller are rotatably supported by a roller bearing, and the tension of the belt is detected by a tension sensor as Tension signal To output, the roller bearing is displaced in the first direction by the displacement mechanism according to the tension signal of the tension sensor and the tension is constant. The method according to claim 14, wherein the tension is detected by a hanging amount of the lower belt at an intermediate position between the first roller and the second roller. The edge position control method according to claim 9, further comprising the step of rotatably supporting both ends of the shaft of the second roller by a pair of roller bearings; and by using one pair of the second roller a position sensor detects a position of the pair of roller bearings in the first direction; and each of the pair of roller bearings is displaced in the first direction by a pair of displacement mechanisms; and the second roller belt edge position is sensed The position of the edge in the second direction is detected on the second roller; and the tension of the belt is constantly maintained by the tension controller, and the bearing position correction signal is output to the pair of displacement mechanisms. The tension signal of the tension sensor constantly maintains the tension of the belt, and the pair of tension sensors are respectively disposed between the pair of roller bearings and the pair of displacement mechanisms, and the bearing position correction signal is for suppressing the belt edge A signal that changes in position on the second roller.