TW201412626A - Film floating apparatus, tenter, solution film-forming equipment and process - Google Patents

Abstract

A floating apparatus which can stably float a film to improve vibration resistance resulting from outer disturbance, a tenter, a solution film-forming equipment and process are provided. A gas flow control exhaust part 60 is disposed on a nozzle plate 55 to construct a blast head 50. A plurality of blow-off holes 55b are formed on the nozzle plate 55. The gas flow control exhaust part 60 is constructed by an exhaust gutter 61. The exhaust gutter 61 is formed with a length equal to a width of the blast head 50 in a width direction of a film 30. A dry air 49 is blown out from the blow-off hole 55b of the blast head 50 to float the film 30. The dry air 49 after hitting the film 30 is exhausted by the exhaust gutter 61 to a side of the film 30. The dry air 49 does not stay near the film 30. Even if the film 30 vibrates because of outer disturbance, the vibration is suppressed so that the vibration resistance is excellent.

Description

Film floating device, tenter, solution film forming device and method

The present invention relates to a film floating device, a tenter, a solution film forming apparatus and method for floating a strip-shaped film.

Since the polymer film has excellent light transmittance or flexibility and can be lightly thinned, it is used in various fields as an optical functional film. Among them, a celluloseulosic ester film such as Cellulose acylate has a toughness or a low birefringence in addition to the above characteristics. The cellulose ester film is used as a protective film or an optical compensation film of a polarizing plate which is a constituent member of a liquid crystal display (LCD) which has been expanding in the market in recent years.

One of the methods for producing a polymer film is a solution film forming method. In the solution film forming method, a dope containing a polymer and a solvent is cast from a casting die onto a support to form a cast film. Further, after the cast film is solidified to some extent and has self-supporting properties, the cast film is peeled off from the support as a wet film. Then, by using a tenter, the both end portions of the wet film are held and transported, and the transfer is performed. The film was dried during the transfer. Thereafter, the both end portions of the film were cut by a side slitter, and the film was passed through a drying device and then wound by a winding device.

A tenter, in particular, a pin tenter for drying a wet film having a high solvent content, uses a pin clip having a plurality of needles to puncture the needle into both sides of the film In the air blower, the air is blown out from the air blower, and the film is transported while the film is floated (see Patent Document 1). Furthermore, in the patent document 2, a porous plate nozzle having a plurality of blowing holes is used as the film conveying device, and the film is conveyed while the film is being floated.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2003-260741

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2008-247507

However, with the increase in size and weight of flat-panel displays in recent years, the film is broadened or thinned, and the stability of floating in the conventional film transfer method is insufficient. . For example, if the floating of the film is unstable, the film may come into contact with the perforated plate nozzle or the like to cause scratches or breakage. If a scratch is generated, the part cannot be used as a product, and product loss occurs. Moreover, in the case of severe damage, the film production line is stopped, and thus the startup process and the like take a lot of effort and time. Therefore, it is desired to have a new floating stabilization method that copes with the broadening or thinning of the film.

In the method of using the perforated plate nozzle of the patent document 1, air is blown uniformly from the blowing hole of the perforated plate nozzle, and the drooping of the film is suppressed, and it is stably floated and moved. give away. However, although the blowing pressure is equal, since the pressure under the film is small, when floating due to external disturbance becomes unstable, there is a problem that it is difficult to stabilize. Further, in the perforated plate nozzle of Patent Document 2, by forming a convex-concave shape in the conveying direction, the static pressure under the film is reduced, and the amount of floating is suppressed. However, since the pressure under the film is low, in the same manner as in Patent Document 1, when floating due to external disturbance becomes unstable, there is a problem that it is difficult to stabilize.

An object of the present invention is to provide a film floating device, a tenter, and a solution film forming apparatus and method which can suppress a film from being stably floated due to the influence of external disturbance.

In order to achieve the object, the film floating device of the present invention includes a blower head and an air flow control exhaust portion. The air supply head has a nozzle face. The nozzle surface is disposed to face the film surface. A plurality of blowing holes for blowing a gas toward the film surface are disposed on the nozzle surface. The air flow control exhaust portion is disposed on the nozzle surface in the width direction of the film, and discharges the gas from the blow hole to the side of the film.

Further, it is preferable that the nozzle surface and the air flow control exhaust portion are alternately arranged in the transport direction of the film. Further, it is preferable that the length of the nozzle surface in the transport direction of the film is W4, the length of the airflow control exhaust portion in the transport direction of the film is W2, and the interval in the transport direction of the film of the airflow control exhaust portion is preferably set. When P (P=W2+W4), the ratio (W2/P) is 0.1 or more and 0.3 or less.

The air flow control exhaust portion preferably includes an exhaust groove and an exhaust port that is open on both sides in the film width direction of the exhaust groove. The venting groove preferably has a pair of separators. 1 pair of partitions towards The film surface is protruded and arranged to be spaced apart from each other in the film transport direction. A pair of guide plates are provided at the front end of the partition. The guide sheets are obliquely continuous between the pair of partitions from the projecting end of one of the partitions toward the base end of the other of the partitions.

It is preferable to provide a side plate which blocks both ends in the width direction of the film on the exhaust groove. A vent hole is formed in the side plate. The exhaust port constitutes an exhaust port.

The blowing pressure of the gas in the blowing hole is preferably 30 Pa or more and 150 Pa or less, and the distance from the blowing hole to the film is 20 mm or more and 100 mm or less. Further, the pressure P1 near the nozzle surface, more specifically, the pressure P1 at a position separated from the nozzle surface by 20 mm, and the pressure near the film surface, more specifically, the pressure P2 at a position separated from the film surface by 5 mm downward is preferable. It is 5 Pa or more and 40 Pa or less. Further, it is preferable that the pressure difference (P2-P1) between the pressure P1 at a position separated from the nozzle surface by 20 mm and the pressure P2 at a position separated from the film surface by 5 mm is 2 Pa or less.

The tenter of the present invention includes the film floating device and a film conveying device. The film conveying device holds both side edges of the film by the holding portion, and the holding portion circulates in the conveying direction of the film to convey the film. The gas is a temperature-conditioned dry air for evaporating the solvent in the membrane.

The solution film forming apparatus of the present invention includes a casting device, the tenter that holds and conveys the wet film conveyed from the casting device, and a drying device that dries the wet film conveyed from the tenter. The casting device casts a dope containing a polymer and a solvent on the traveling annular support to form a strip-shaped cast film, and the cast film is peeled off as a wet film.

The solution film forming method of the present invention comprises a casting step, a film carrying step, and pulling The step of drying, and the drying step of drying the film subjected to the tentering step. The casting step is performed by casting a dope containing a polymer and a solvent onto a traveling annular support to form a strip-shaped cast film, and the cast film is taken as a wet film and peeled off from the support. In the film transporting step, both side edges of the wet film which have passed through the casting step are held by the holding portion, and the wet film is conveyed. In the tentering step, the drying gas is blown from the nozzle surface having the plurality of blowing holes toward the film surface of the wetting film in the film transporting step by the air blowing head, whereby the wet film is dried. In this drying, the exhaust portion is controlled by the air current, and the dry gas that has hit the film surface is discharged to the side of the film. The air flow control exhaust portion is partitioned in the conveying direction of the wet film, and is disposed in the air blowing head along the film width direction.

According to the present invention, the gas is blown from the blowing hole of the nozzle surface, and the gas is controlled to discharge the gas from the blowing hole to the side of the film by the air flow, whereby the pressure in the vicinity of the film surface and the vicinity of the nozzle surface can be made substantially the same. Thereby, the floating does not become unstable due to external disturbance, and the film can be stably floated. Moreover, drying is performed in a state where the film is stably floated, whereby more uniform optical characteristics are obtained over the entire surface of the film.

10‧‧‧solution film making equipment

11‧‧‧casting device

12‧‧‧Transition roller

13‧‧‧ Needle plate tenter

14‧‧‧布铗拉机

15a, 15b‧‧‧ side slitting machine

16‧‧‧Drying device

17‧‧‧Winding device

20‧‧‧Liquor

21‧‧

22‧‧‧Roller

23‧‧‧ Stripping roller

24‧‧‧Decompression chamber

25‧‧‧Concentrate manufacturing equipment

26‧‧‧ flow path

27‧‧‧Motor

28‧‧‧cast film

29‧‧‧Heat Transfer Medium Circulator

30‧‧‧ Wet film

30a‧‧‧film surface

30b‧‧‧ datum

34‧‧‧Large room

35‧‧‧film conveying device

36‧‧‧membrane floating device

37‧‧‧ film

38, 82‧‧‧ Roll

39‧‧‧ Roll film

40‧‧‧Circular chain

41‧‧‧ Track

42‧‧‧Sprocket

43‧‧‧ needle board

44‧‧‧ needle

49‧‧‧ Dry air

50, 51, 72, 76, 110, 120‧‧‧

52‧‧‧Air duct

53‧‧‧Air blower

54‧‧‧temperature regulator

55, 75, 100, 115‧‧‧ nozzle plate

55a‧‧・Nozzle surface

55b, 75b, 100a, 115b‧‧‧ blow out holes

55c‧‧‧Installation edge

56‧‧‧floor

56a‧‧‧The central part of the film transport direction

56b‧‧‧Linking Department

57‧‧‧ side panels

57a‧‧‧ tube connector

58‧‧‧End board

60, 75c‧‧‧ airflow control exhaust

61, 71, 74, 77‧‧ ‧ venting slots

62‧‧‧floor

63, 70‧‧ ‧ partition

64, 74a, 74b, 77a, 77b‧‧‧ guide boards

65‧‧‧Exhaust ditch

66‧‧‧Exhaust clearance

67‧‧‧ side panels

68‧‧‧Exhaust port

78‧‧‧Testing machine

79‧‧‧Band film

80‧‧‧ fixture

81‧‧‧ weight

85‧‧‧ strain gauge

86‧‧‧PC

101‧‧‧Multiple air supply head

105‧‧‧Slit-like opening

106, 116‧‧‧ nozzle

D1‧‧‧ diameter

H2‧‧‧ Height

HF‧‧‧Floating height

L1, L2‧‧‧ length

P‧‧‧ spacing

P0‧‧‧blowing pressure

P1, P2‧‧‧ pressure

U1‧‧‧Float

W1‧‧‧ width of the lower air supply head

W2‧‧‧ vent width

W3‧‧‧ opening width of the exhaust gap

W4‧‧·The width of the nozzle face

X‧‧‧ direction

△U‧‧‧Floating volume change

θ 1 , θ 2‧‧‧ tilt angle

Fig. 1 is a side view showing an outline of an example of a solution film forming apparatus of the present invention.

Fig. 2 is a front cross-sectional view showing an outline of an example of a tenter according to the present invention.

Fig. 3 is a perspective view showing an example of a lower air blowing head.

Fig. 4 is a side view showing a part of the lower air blowing head in a cross section.

Fig. 5 is a perspective view showing an example of a film floating device including a one-unit air blowing head.

FIG. 6 is a view showing an example of the flow of dry air from the blow hole, and is a cross-sectional view taken along line VI-VI of FIG. 4 .

FIG. 7 is a view showing an example of the flow of dry air from the blowing holes, and is a cross-sectional view taken along line VII-VII in FIG. 4 .

Fig. 8 is a front view for explaining a change in the amount of floating and the amount of floating of the film.

Fig. 9 is a side view showing a part of an example of a blower head showing another embodiment of changing the shape of the exhaust groove.

FIG. 10 is a cross-sectional view showing an example of an exhaust groove of another embodiment in which the shape of the guide plate is changed.

Fig. 11 is a cross-sectional view showing an example of an exhaust groove of another embodiment in which the shape of the guide plate is changed.

FIG. 12 is a side view showing a part of an example of a blower head of another embodiment in which a nozzle plate is arranged in a mountain shape instead of an exhaust groove.

FIG. 13 is a side view showing an example of a schematic configuration of a testing machine.

Fig. 14 is a perspective view showing a blower head used in Experiment 6.

Fig. 15 is a perspective view showing a blower head used in Experiment 7.

Fig. 16 is a perspective view showing a blower head used in Experiment 8.

1 shows an example of a solution film forming apparatus 10, which includes the solution film forming apparatus 10 The casting device 11, the pin tenter 13, the clip tenter 14, the side slitter 15a, the side slitter 15b, the drying device 16, and the winding device 17.

The casting device 11 includes a die 21, a drum 22, a stripping roller 23, and a decompression chamber 24. The mold 21 flows the dope 20 supplied from the dope manufacturing apparatus 25 into a bead 26 on the circumferential surface of the drum 22. The dope 20 is obtained, for example, by dissolving deuterated cellulose in a solvent.

The drum 22 is rotated by the motor 27. Thereby, the flow path 26 is elongated on the circumferential surface of the drum, thereby forming the casting film 28. That is, the drum 22 is a form of the support. The decompression chamber 24 decompresses the back side of the flow path 26 (the upstream side in the rotation direction of the drum 22) to eliminate unstable sway of the flow path 26.

A heat transfer medium circulation machine 29 is connected to the drum 22. The heat transfer medium circulation machine 29 conveys the cooled heat transfer medium to the inside of the drum 22 to maintain the circumferential surface of the drum 22 at a fixed temperature. By this cooling, the curing is carried out to such an extent that the casting film 28 is self-supporting even when peeled off during the period in which the drum 22 is rotated for about 3/4 of a week.

The stripping roller 23 is provided on the upstream side in the rotation direction of the drum 22 and in the vicinity of the circumferential surface of the drum 22 with respect to the mold 21. The stripping roller 23 supports the casting film 28 which is solidified by cooling, and the casting film 28 is peeled off from the drum 22. The stripped cast film 28 is sent as a wet film 30 to the pin tenter 13 via the transition roller 12.

The pin tenter 13 includes a film transport device 35 and a film floating device 36. In the needle card tenter 13, the wet film 30 is conveyed by the film transport device 35, and dried by the dry air by the film floating device 36. That is, the pin tenter 13 is a form of a tenter.

The dried film 30 is sent to the side slitter 15a. The side slitter 15a cuts both side portions of the film 30 including the holding marks caused by the needles 44 of the pin tenter 13.

In the fabric tenter 14, the both side edges of the film 30 dried by the pin tenter 13 are held, and the film 30 is extended in the film width direction and the film conveyance direction. With this extension, a film 37 having the desired optical properties is formed. The film 37 is cut off at both sides by the side slitter 15b, and then sent to the drying device 16. Further, depending on the optical characteristics of the film 37, the fabric tenter 14 may not be used, and may be sent directly to the drying device 16 in a meandering manner.

In the drying device 16, the film 37 is wound around a plurality of rollers 38 and conveyed. The ambient gas inside the drying device 16 is adjusted by temperature or humidity or the like by a thermostat (not shown). During the transport of the film 37, the solvent evaporates and is dried. Then, the film 37 is wound into a roll shape by the winding device 17. The roll film 39 obtained by the present invention is used, for example, for a retardation film or a polarizing plate protective film.

The needle card tenter 13 of the present invention includes a tenter chamber 34, a film transporting device 35, and a film floating device 36. The tenter chamber 34 is airtight, and the dried solvent or the like does not leak from the wet film 30 to the outside. Further, a transition portion from the casting device 11 to the pin tenter 13 or a connection portion from the pin tenter 13 to the fabric tenter 14 and a connection portion from the fabric tenter 14 to the drying device 16 They also become airtight structures so that the solvent does not leak to the outside.

As shown in FIG. 2, the film conveying device 35 includes an endless chain 40, a rail 41, a sprocket 42 (refer to FIG. 1), and a pin plate 43. Circular chain 40 along The wet film 30 is disposed on both sides of the traveling path, and is provided in a pair. These endless chains 40 are mounted on the sprocket 42. A motor is coupled to a sprocket 42. The motor rotates the sprocket 42 to circulate the endless chain 40.

The endless chain 40 between the sprockets 42 is supported by the rails 41. A needle plate 43 is attached to the endless chain 40 at a fixed pitch. A plurality of needles 44 are protruded from the needle plate 43. The needle 44 is inserted into both side edges of the wet film 30 to support the wet film 30. That is, the needle 44 is one form of the holding portion.

As shown in FIG. 1, in the present embodiment, the film transport path is folded back halfway, for example, in a three-stage manner from the viewpoint of equipment efficiency. Along with this, the endless chain 40 is also folded back at the sprocket 42.

A film pressing brush (not shown) is disposed in the film introduction portion of the needle card tenter 13. The film pressing brush presses the side edge portion of the film to the root side of the needle 44, so that the needle 44 surely penetrates the wet film 30. The wet film 30, which is held by the needles 44 at both side edges, is transferred to the X direction by the cyclic movement of the endless chain 40.

As shown in FIG. 2, the film floating device 36 includes a lower air blowing head 50, an upper air blowing head 51, a blow pipe 52, a blower 53, and a temperature adjuster 54. The lower air blowing head 50 is disposed below the film 30 so as to sandwich the film 30, and the upper air blowing head 51 is disposed above the film 30.

As shown in FIGS. 3 and 4, the lower air blowing head 50 includes a nozzle plate 55, a bottom plate 56, two side plates 57, and two end plates 58, and is formed in a substantially box shape. The nozzle plate 55 is disposed to face the transport path of the wet film 30. A plurality of blowing holes 55b are formed in the nozzle surface 55a. Both ends of the nozzle plate 55 slightly extend from the both end plates 58. By this The extended portion forms a mounting end edge portion 55c. The blowing hole 55b of the mounting end edge portion 55c does not communicate with the inside of the lower air blowing head 50, and thus does not contribute to blowing. In addition, the mounting end edge portion 55c may be omitted.

As shown in FIG. 4, the film conveyance direction center part 56a of the bottom plate 56 is parallel with respect to the nozzle surface 55a. In addition, the connection portion 56b that connects the film conveyance direction center portion 56a and the both end plates 58 is inclined so as to decrease in distance from the nozzle face 55a toward the end plate 58.

A pipe connecting cylinder 57a is formed on one of the side plates 57. The air supply duct 52 is connected via the tube connection cylinder 57a (see FIG. 2). Further, a rectifying plate is disposed in the upper air blowing head 51 as needed. The rectifying plate has a substantially constant air blowing pressure from each of the blowing holes 55b.

An exhaust groove 61 is disposed on the nozzle surface 55a in the film width direction. For example, four exhaust grooves 61 are arranged at a fixed pitch in the film transport direction. Thereby, the nozzle plate 55 and the exhaust groove 61 are alternately arranged in the film conveying direction.

As shown in FIG. 3, the exhaust groove 61 is formed in a substantially U shape by the bottom plate 62 and the pair of partition plates 63. The separator 63 is continuous at both end edges of the bottom plate 62 in the film transport direction, and protrudes toward the film surface 30a. The exhaust groove 61 constitutes an air flow control exhaust unit 60 for blowing a gas, and the air flow control exhaust unit 60 is for discharging the gas from the blowing hole 55b to the both sides of the film 30 after hitting the film surface 30a.

The front end of the partition 63 is continuously connected to the guide plate 64. The guide plate 64 is inside the exhaust groove 61, and the front end faces obliquely downward. A V-shaped exhaust groove 65 is formed by the pair of guide plates 64. Moreover, the front end edges of the pair of guiding plates 64 are not closely connected to each other to form Exhaust clearance 66.

As shown in FIGS. 6 and 7, the end portions of the exhaust groove 61 in the film width direction are closed by the side plates 67. As shown in FIG. 3, the side plate 67 is coupled to the side edges of the bottom plate 62, the partition plate 63, and the guide plate 64. The exhaust port 68 is open at a lower portion of the side plate 67. The exhaust port 68 is formed in a rectangular shape that is long in the horizontal direction. The air blown from the blowing hole 55b and hitting the film 30 passes through the exhaust groove 65 or the exhaust port 68 of the exhaust groove 61, and is sent to both sides of the air blowing head 51. Thereby, the air blown out from the blowing hole 55b and hitting the film 30 does not stay in the vicinity of the film 30.

Further, a flow rate adjusting mechanism such as an opening area adjusting valve or an exhaust fan may be provided in the exhaust port 68. The flow rate adjustment mechanism finely adjusts the amount of exhaust gas from the exhaust port 68. Thereby, the discharge amount of the air blown out from the blowing hole 55b and hitting the film 30 is adjusted. Further, in the first embodiment, the exhaust ports 68 are provided on both sides of the exhaust groove 65, but the exhaust port 68 may be provided only on one side. In this case, the width W3 is gradually increased so that the opening width W3 of the exhaust gap 66 where the exhaust port side is not formed is gradually increased compared to the opening width W3 of the exhaust gap 66 on the exhaust port side. Exhaust can be performed without unevenness in the width direction.

The blowing pressure P0 of the dry air 49 in the blowing hole 55b is preferably 20 Pa or more and 155 Pa or less. It is particularly preferably 20 Pa or more and 120 Pa or less. If the blowing pressure P0 is 30 Pa or more, the film 30 does not pass through its own weight, and thus floats stably. If it is 150 Pa or less, the pressure immediately below the film 30 does not become excessive. Further, even if the vibration caused by the external disturbance is caused to increase the vibration, the vibration can be suppressed and the floating stability can be achieved. The distance from the blowing hole 55b to the film 30 is the floating height HF It is preferably 20 mm or more and 100 mm or less, and particularly preferably 40 mm or more and 100 mm or less. When the floating height HF is 20 mm or more and 100 mm or less, the pressure under the film becomes uniform, and the vibration during floating is reduced.

The pressure P1 at a position separated from the nozzle surface 55a by 20 mm upward and the pressure P2 at a position separated from the film surface 30a by 5 mm are preferably 5 Pa or more and 40 Pa or less. It is particularly preferably 10 Pa or more and 25 Pa or less. If the pressure P1 and the pressure P2 are 5 Pa or more, the film 30 does not pass through the self-weight, and can be floated and transported. Further, if these pressures P1 and P2 are 40 Pa or less, the film 30 does not bulge in a gentle convex shape in the width direction, so that the amount of floating is not excessive or the external disturbance resistance is insufficient.

The pressure difference (P2-P1) between the pressure P1 and the pressure P2 is preferably 2 Pa or less. If the pressure difference (P2-P1) is 2 Pa or less, the pressure becomes substantially uniform, and the floating of the film 30 is not unstable due to the vibration caused by the external disturbance.

As shown in FIG. 8, the film 30 has a shape which bulges in the gas blowing direction by the gas from the blowing hole. Therefore, when the pressure P2 is measured based on the film surface 30a, it is measured at the position where it changes every time. In order to avoid this, when the film surface 30a is used as a reference, the film holding surface (hereinafter referred to as a reference surface) 30b by the needle 44 of the needle plate 43 is actually used as the film surface 30a from the reference. The distance from the face 30b determines the measurement point of the pressure P2. In addition, in FIG. 8, in order to explain the floating amount U1 of the film 30 and the floating amount fluctuation ΔU, the bulging shape of the film 30 is drawn more than the actual shape. Moreover, the illustration of the air blowing head on the upper side is omitted.

The floating amount U1 of the film 30 is an average value of the height from the reference surface 30b at the center in the width direction of the film 30 when the film 30 is floated by the gas blowing. The floating amount U1 is an average value of the heights in a time period of, for example, 10 seconds or more and 60 seconds or less. The fluctuation amount ΔU is the maximum value of the fluctuation range of the floating amount U1 in the center in the width direction of the film 30 when the floating amount U1 is obtained. The frequency of the film vibration and the fluctuation of the floating amount fluctuation ΔU are different from each other, and the film vibration is 15 Hz or more and 200 Hz or less depending on the frequency of the blown air, and the frequency of the floating amount fluctuation ΔU is 0.01 Hz or more and 5 Hz or less.

As shown in FIG. 4, the ratio (W2/P) of the width W2 of the exhaust groove 61 to the pitch P of the exhaust groove 61 is preferably 0.1 or more and 0.3 or less. In addition, the pitch P is an interval between the exhaust grooves 61 when the exhaust grooves 61 are arranged in the film transport direction on the nozzle surface of the lower air blowing head 50. When the width of the nozzle surface 55a between the respective exhaust grooves 61 (the length of the nozzle surface 55a in the film transport direction) is W4, the pitch P is (W2+W4). When the ratio of the width of the exhaust groove 61 to the pitch P, that is, the ratio (W2/P) is 0.1 or more, the effect of the exhaust gas is increased, and the external disturbance resistance is stronger than that of the porous plate of Experiment 1 to be described later. Further, if the ratio (W2/P) is 0.3 or less, the amount of supply air is not insufficient, and the floating is stabilized. In addition, in order to illustrate the exhaust groove 61 as the airflow control exhaust unit 60, in FIGS. 2 to 9, the size of the exhaust groove 61 is enlarged compared to the nozzle surface 55a, and the exhaust is exaggerated. Slot 61. Therefore, in these FIGS. 2 to 9, it is not the size that satisfies the relationship of W2/P.

Further, when the gap between the tips of the guide plates 64, that is, the width of the exhaust gap 66 is W3, the ratio of the width W2 of the upper end of the exhaust groove 61 is W3/W2 is preferably 0.02 or more and 0.05 or less. If it is 0.02 or more, the external disturbance tolerance increases due to the effect of the exhaust gas. Further, if it is 0.05 or less, the effect of the exhaust gas does not increase, and the pressure under the film is substantially uniform.

As shown in FIG. 3, the length L2 of the exhaust groove 61 is preferably the same as the width W1 of the lower air blowing head 50. In this case, the dry air 49 that hits the film surface 30a can be efficiently discharged to both sides in the film width direction by the exhaust groove 61 in the floating region of the film 30.

The height H2 of the partition plate 63 of the exhaust groove 61 is preferably twice or more and 25 times or less the diameter D1 of the blow-out hole 55b. If it is 2 times or more, the airflow flows to the exhaust groove 65, and the effect of the exhaust gas is obtained. Further, if it is 25 times or less, the attenuation of the discharged air from the nozzle plate 55 is reduced, and the floating is stabilized.

As shown in FIG. 4, the inclination angle θ1 of the guide plate 64 with respect to the nozzle surface 55a is preferably 5° or more and 30° or less. If the inclination angle θ 1 is 5° or more, the airflow easily enters the exhaust groove 65. Moreover, if it is 30 degrees or less, the pressure of the periphery of the exhaust groove 61 becomes uniform.

As shown in Fig. 2, the upper air blowing head 51 is also configured in the same manner as the lower air blowing head 50, and the same components are denoted by the same reference numerals, and the overlapping description will be omitted. As shown in FIG. 5, in the present embodiment, the lower air blowing head 50 and the upper air blowing head 51 are set as one set, and the three sets of air blowing heads are arranged as one unit. Further, the film floating device 36 is configured by providing only the necessary number of cells in accordance with the film transport length of the film transport device 35.

Next, the action of this embodiment will be described. As shown in Fig. 2, in the pin tenter 13, the wet film 30 is inserted into the side edges of the needles 44, and both sides are The edge is kept. The needle 44 is held on the needle plate 43, and the needle plate 43 is fixed to the rotationally moving endless chain 40. The endless chain 40 is rotated by the sprocket 42 (refer to FIG. 1) in a state of being supported by the rail 41. Thereby, the wet film 30 travels in the X direction in the pin tenter 13.

Dry air 49 is introduced into the traveling wet film 30 from the lower air blowing head 50 and the blowing hole 55b of the upper air blowing head 51. After the dry air 49 hits the film surface 30a as shown in FIG. 6, as shown in FIG. 7, it is discharged from the exhaust groove 61 to both sides of the film 30. Therefore, the pressure difference between the static pressure in the vicinity of the blowing hole 55b and the static pressure in the vicinity of the film surface 30a disappears, and even if the film 30 is disturbed by the external disturbance, the disturbance is immediately suppressed, and the large disturbance is not developed. Therefore, the film surface 30a does not shake, so that the film 30 can be stably floated. Thereby, the lower air blowing head 50 and the upper air blowing head 51 are not in contact with the film surface 30a, and are scratched or damaged. Further, since the film 30 is dried in a state of being stably floated, more uniform optical characteristics are obtained over the entire surface of the film 30.

In particular, the airflow control exhaust portion 60 is disposed long in the film width direction, and the exhaust port 68 is located at both end portions in the film width direction, so that the dry air 49 blown out for the film 30 to float can be efficiently floated from the film. The range area is sent to both sides of the film. Thereby, the difference between the pressure in the vicinity of the nozzle surface 55a in which the blowing hole 55b is formed and the pressure in the vicinity of the film surface 30a can be further reduced. Therefore, with respect to the vibration of the film 30 caused by the external disturbance, the vibration can be suppressed little, and the vibration resistance is improved.

Further, in the above-described embodiment, as shown in FIG. 4, the partition plate 63 of the exhaust groove 61 is disposed to be orthogonal to the nozzle surface 55a. However, the present invention is not limited thereto, and as shown in FIG. 9, the partition plate 70 may be used. The inside of the exhaust groove 71 is disposed at an inclination angle θ 2 The air head 72 is supplied. In the respective embodiments, the same components as those in the embodiment shown in FIGS. 1 to 7 are denoted by the same reference numerals, and the description thereof will not be repeated.

Fig. 10 shows an exhaust groove 74 of another embodiment in which one of the pair of guide plates 74a and 74b is formed longer than the other. FIG. 11 shows an exhaust groove 77 of another embodiment in which one pair of the guide sheets 77a and the guide sheets 77b are bent downward. The opening width W3 of the exhaust gap 66 is a gap from the front end of the short guide plate 74a to the long guide plate 74b in the case of FIG. In the case of FIG. 11, the gap between the front ends of the guide sheets 77a and the guide sheets 77b is the opening width W3 of the exhaust gap 66.

FIG. 12 shows a blower head 76 of another embodiment in which a nozzle plate 75 having a plurality of blow holes 75b is disposed in a mountain shape instead of the individual exhaust grooves 61 and the exhaust grooves 71. In this case, the blowing holes 75b of the valley portions between the mountain shapes are eliminated, and the air flow control exhausting portion 75c is constituted by the valley portions. In addition, the blowing rate per unit area of the blowing hole 75b of the valley portion may be made smaller than that of the top portion, and the blowing wind may be weakened, and the weakened portion may be used as the air flow to control the exhaust portion.

In the above embodiment, the lower air blowing head 50 and the upper air blowing head 51 are disposed to face the film 30. However, the upper air blowing head 51 may be omitted and the lower air blowing head 50 may be used for floating transportation. However, if the vibration resistance of the external disturbance is considered, it is preferable to provide the air blowing head up and down.

In the above embodiment, the film floating device 36 of the pin tenter 13 has been described. However, the present invention is not limited thereto, and may be used for the fabric tenter 14 or other film transporting device. Moreover, it is not limited to film transport, and can also be used for floating of other strip materials. give away.

In the solution film forming apparatus 10 of the present invention, the width of the film as a product is preferably 600 mm or more, and more preferably 1400 mm or more and 2500 mm or less. In addition, it is also effective in the case where the width of the film is more than 2,500 mm. Further, the film thickness of the film is preferably 15 μm or more and 80 μm or less. The polymer which is a raw material of the polymer film is not particularly limited, and examples thereof include deuterated cellulose or cyclic polyolefin.

The mercapto group used in the deuterated cellulose of the present invention may be only one type, or two or more types of mercapto groups may be used. When two or more kinds of anthracenyl groups are used, one of them is preferably an ethyl group. The ratio of the esterification of the hydroxy group of the cellulose with a carboxylic acid, that is, the degree of substitution of the thiol group preferably satisfies all of the following formulas (I) to (III). Further, in the following formulae (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. Further, 90% by weight or more of Triacetyl Cellulose (TAC) is preferably 0.1 mm or more and 4 mm or less.

(I) 2.0≦A+B≦3.0

(II) 1.0≦A≦3.0

(III)0≦B≦2.9

The total substitution degree A+B of the fluorenyl group is more preferably 2.20 or more and 2.90 or less, and particularly preferably 2.40 or more and 2.88 or less. Further, the degree of substitution 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.

The details of the deuterated cellulose are described in paragraphs [0140] to [0195] of JP-A-2005-104148. These records also apply In the present invention. Further, additives such as a solvent, a plasticizer, a deterioration preventive agent, an ultraviolet absorber (UV agent), an optical anisotropy control agent, a retardation control agent, a dye, a matting agent, a release agent, and a peeling accelerator are also used. Also described in detail in paragraphs [0196] to [0516] of Japanese Patent Laid-Open No. 2005-104148.

In order to confirm the effect by the film floating device 36 of the present invention, the test was performed using the testing machine 78 as shown in FIG. First, one end of the strip film 79 is fixed to the jig 80, and the weight 81 is attached to the other end, and the strip film 79 is horizontally supported by the roller 82. The lower air blowing head 50 is disposed below the belt-shaped film 79 so that the upper air blowing head 51 is disposed above the belt-shaped film 79, and the lower air blowing head 50 and the upper air blowing head 51 are grouped as a group. In the film transport direction (longitudinal direction), three groups are arranged as one unit. Air is supplied to the lower air blowing head 50 and the upper air blowing head 51 of the one unit, and the belt-shaped film 79 is floated. As the strip film 79, a TAC film having a thickness of 25 μm and a width of 1800 mm was used.

[Examples]

(Experiment 1)

In Experiment 1, the lower air blowing head 50 and the upper air blowing head 51 shown in Fig. 3 having the nozzle plate 55 including a plurality of blowing holes 55b having a diameter D1 of 2.5 mm and openings per unit area were used. The rate is set to 10% punching plate. Four exhaust grooves 61 are provided on the nozzle plate 55 in the film conveying direction at a pitch P of 500 mm. The length L2 of the exhaust groove 61 was set to 1800 mm in accordance with the width of the strip film 79, the width W2 of the exhaust groove 61 was 150 mm, and the height H2 was set to 45 mm. The ratio (W2/P) is 0.3. The inclination angle θ 1 of the guide plate 64 with respect to the nozzle face 55a is set to 6°. The opening width W3 of the exhaust gap 66 was set to 4 mm, and the opening area was set to 7200 mm ² . The gas discharge pressure P0 was set to 90 Pa, and the distance from the nozzle surface 55a to the strip film 79, that is, the floating height HF was set to 90 mm.

Dry air is supplied to the lower air blowing head 50 and the upper air blowing head 51. First, the strip film 79 is floated by the blowing of the dry air from the lower air blowing head 50. Then, by the blowing of the dry air from the upper air blowing head 51, the upward movement of the belt-shaped film 79 is suppressed, and the floating amount U1 is reduced. Therefore, the amount of air blown from the lower air blowing head 50 is set to the amount of air that can float the belt-shaped film 79 in consideration of the own weight of the strip-shaped film 79. Further, the blowing pressure of the air blowing amount of the upper air blowing head 51 is about 5 Pa. Further, when the floating amount U1 is large, the air blowing amount of the upper air blowing head 51 is gradually increased (for example, about 1/5 of the air blowing amount of the lower air blowing head 50). Further, the amount (U1 + ΔU) obtained by adding the floating amount U1 and the floating amount variation ΔU is smaller than the gap {2 × (HF - H2)} of the lower air blowing head 50 and the upper air blowing head 51. Way to set the air supply volume. Thereby, the strip film 79 does not come into contact with the lower air blowing head 50 and the upper air blowing head 51.

The air pressure in the vicinity of the nozzle surface 55a is measured by a pressure sensor GC30 manufactured by a Nagano meter (a), which is sufficiently attenuated by the airflow ejected from the nozzle surface 55a (a position separated by 20 mm from the nozzle surface 55a). Similarly, a sensor was placed in the vicinity of the strip film 79 (a position separated from the reference surface 30b shown in FIG. 8 by 5 mm) to measure the wind pressure under the strip film 79.

The vibration test of the strip film 79 uses a strain gauge 85 and a The human computer 86 performs the measurement. An application program is installed in the personal computer 86 for performing frequency analysis based on a signal from the strain gauge 85 by means of a Fourier Transform (FFT), and measuring the peak of the vibration. The strain gauge 85 is attached to the center portion of the strip film 79 in the longitudinal direction and the width direction. Using the strain gauge 85, the number of vibrations of the strip-shaped film 79 vibrated by the fluctuation of the wind pressure was measured, and the vibration peaks were evaluated in four levels. The strain gauge 85 used YEFLA-2 manufactured by Tokyo Institute of Testing Instruments. Further, as an application for obtaining a vibration peak by strain vibration, a macro that performs frequency analysis using an FFT corresponding variable value is used. Further, the floating amount U1 and the floating amount variation ΔU in Fig. 8 were measured using a laser displacement meter LKG-3000 manufactured by KEYENCE Co., Ltd.

The external disturbance tolerance test is applied to the center position in the longitudinal direction of the strip film 79, and the amplitude of 90 mm which is the gap between the lower air blowing head 50 and the upper air blowing head 51 is applied once in the vertical direction orthogonal to the film surface 30a. The time s (seconds) until the film vibration was attenuated was evaluated in stages.

(Experiment 2)

In the experiment 2, the same conditions as in Experiment 1 were used except that the air blowing head 72 in which the partition plate 70 of the exhaust groove 71 was inclined inward was used as shown in FIG. The inclination angle θ 2 of the partition plate 70 with respect to the vertical line is set to 10°, and the opening width W3 of the exhaust gap 66 of the exhaust groove 65 is set to 4 mm.

(Experiment 3)

Experiment 3 except that the guide plates having different lengths as shown in FIG. 10 were used. 74a and the exhaust groove 74 of the guide plate 74b were set to the same conditions as the experiment 1.

(Experiment 4)

In the experiment 4, the same conditions as in Experiment 1 were used except that the guide groove 77a and the guide groove 77b which were bent so as to protrude inward as shown in Fig. 11 were used.

(Experiment 5)

In the experiment 5, the same conditions as those in Experiment 1 were used except that the nozzle plate 75 having the blowing holes 75b was inclined with respect to the horizontal line to form a mountain-shaped air blowing head 76 as shown in FIG. The diameter of the blow hole 75b is 2.5 mm, the aperture ratio per unit area is 10%, and the inclination angle of the nozzle plate 75 with respect to the horizontal line is set to 30°.

(Experiment 6)

In Experiment 6, a porous air blowing head 101 having a nozzle plate 100 as shown in Fig. 14 was used, and the nozzle plate 100 was removed from the lower air blowing head 50 and the upper air blowing head 51 of Fig. 3, and a plurality of blowing holes were formed on the entire surface. 100a. Other than the above, the same conditions as in Experiment 1 were set. The diameter D1 of the blowing hole 100a of the nozzle plate 100 was 2.5 mm, and the aperture ratio per unit area was set to 10%.

(Experiment 7)

In the experiment 7, the air blowing head 110 obtained by arranging four rows of the nozzles 106 in the film conveying direction at a pitch P of 500 mm as shown in Fig. 15 having the slit-like opening 105 in the film width direction was used. Other than the above, the same conditions as in Experiment 1 were set.

(Experiment 8)

Experiment 8 replaces the nozzle 106 of the slit 7 having the slit-like opening 105, and As shown in FIG. 16 , the nozzles 116 are arranged in four rows in the film transport direction at a pitch P of 500 mm, and the nozzles 116 have a plurality of blow holes 115 b having a diameter D1 of 2.5 mm at the opening position. The nozzle plate 115 having an opening ratio per unit area of 10%. Other than the above, the same conditions as in Experiment 1 were set.

The results of the implementation are shown in Table 1 below.

The evaluation criteria of the membrane vibration test are such that "A" is more than 0 με and is 100 με or less, "B" is more than 100 με and is 250 με or less, "C" is more than 250 με and is 400 με or less, and "D" is more than 400 με. The results of the film vibration test were 50 με in Experiment 1, which was excellent (A). Further, in Experiment 2, it was 110 με, which was good (B). In Experiment 3, it was 60 με, which was excellent (A). In Experiment 4, it was 45 με, which was excellent (A). In Experiment 5, it was 200 με, which was good (B). In Experiment 6, it was 300 με, which was unacceptable (C), and in Experiment 7, it was 550 με, which was unacceptable (D), and in Experiment 8, it was 300 με, which was unacceptable (C). Further, the evaluation (C) of Experiments 6 and 8 is an evaluation of a thin and wide film having a film thickness of 25 μm and a film width of 1800 mm, and the film thickness is also narrowed as the film thickness is increased, for example, a film thickness of 60 μm or a film. A film having a thickness of 1800 mm and having a certain thickness has a possibility of conforming to the standard, and thus is different from the evaluation of the failure (D) of Experiment 7.

The evaluation criteria of the external disturbance tolerance test are such that A is more than 0 and is less than 20 s (seconds), B is more than 20 s and is 50 s or less, C is more than 50 s and is 120 s or less, D is more than 120 s or vibration is not attenuated. . The result of the external disturbance tolerance test was 10 s in Experiment 1, which was excellent (A). Moreover, in Experiment 2, it was 30 s, which was good (B). In Experiment 3 and Experiment 4, it was 10 s, which was excellent (A). In Experiment 5, it was 30 s, which was good (B). In Experiment 6, it was 65 s, which was unacceptable (C), and in Experiment 7, the vibration was increased without attenuating, and it was unsatisfactory (D), and in Experiment 8, it was 180 s, which was unacceptable (D). Further, the evaluation (C) of Experiment 6 is an evaluation of a thin and wide film having a film thickness of 25 μm and a film width of 1800 mm, and the film thickness is, for example, as thick as about 60 μm, and as the film width is narrowed, there is a practical level. The possibility of meeting the standard, from On the other hand, it was evaluated differently from the evaluation of the failure (D) of Experiment 7 and Experiment 8.

According to Experiments 1 to 8, the evaluations in the case where the shapes of the exhaust grooves were different were obtained. Further, in the membrane vibration test and the external disturbance tolerance test, an experiment in which the evaluation is good (B) or more or the evaluation of one of the tests is unqualified (C) and the evaluation of the other test is good (B) The overall evaluation was good, and otherwise it was unqualified. As a result, Experiments 1 to 5 were good, and Experiments 6 to 8 were unqualified.

(Experiment 11 ~ Experiment 13)

In Experiments 11 to 13, the lower range of the gas blowing pressure P0 was confirmed using the lower air blowing head 50 of Experiment 1. The film vibration test and the external disturbance tolerance test were carried out by changing the gas blowing pressure P0. In the experiment 11, the conditions similar to those of the experiment 1 were set except that the gas blowing pressure P0 was changed to 30 Pa. If the gas discharge pressure P0 changes, the pressure near the nozzle P1, the sub-membrane pressure P2, and their difference (P2-P1) change, so it is difficult to say that the conditions are exactly the same as those in Experiment 1, and the expressions using substantially the same conditions are used. . The following experiments are also the same. In the experiment 12, the conditions similar to those of the experiment 1 were set except that the gas blowing pressure P0 was changed to 150 Pa. In the experiment 13, the conditions similar to those in Experiment 1 were set except that the gas blowing pressure P0 was changed to 155 Pa. The experimental results are shown in Table 2 below. From these experiments 11 to 13, it was found that the appropriate range of the gas blowing pressure P0 is 30 Pa or more and 150 Pa or less.

(Experiment 21 ~ Experiment 23)

In Experiments 21 to 23, the lower air blowing head 50 of Experiment 1 was used to change the pressure P1 near the nozzle to perform a membrane vibration test and an external disturbance tolerance test, and confirmed The appropriate range of pressure P1 near the nozzle. In Experiment 21, the conditions similar to those of Experiment 1 were set except that the pressure P1 near the nozzle was changed to 5 Pa. However, in order to change the pressure P1 near the nozzle, the gas blowing pressure P0 is changed. With this change, the sub-film pressure P2 and their difference (P2-P1) changed with respect to Experiment 1. In Experiment 22, except that the pressure P1 in the vicinity of the nozzle was set to 40 Pa, and the gas blowing pressure P0 was changed for this purpose, substantially the same conditions as in Experiment 1 were employed. Similarly, Experiment 23 was set to be substantially the same as Experiment 1 except that the pressure P1 in the vicinity of the nozzle was set to 45 Pa, and the gas blowing pressure P0 was also changed for this purpose. The experimental results are shown in Table 2 below. From these experiments 21 to 23, it was found that the appropriate range of the pressure P1 near the nozzle was 5 Pa or more and 40 Pa or less.

(Experiment 31 ~ Experiment 33)

In Experiments 31 to 33, the lower air blowing head 50 of Experiment 1 was used, and the film pressure test and the external disturbance resistance test were performed by changing the film pressure P2, and the appropriate range of the film pressure P2 was confirmed. In the experiment 31, substantially the same conditions as in Experiment 1 were carried out except that the sub-film pressure P2 was changed to 5 Pa. However, in order to change the sub-film pressure P2, the gas blowing pressure P0 is changed. With this change, the pressure P1 near the nozzle and their difference (P2-P1) changed with respect to Experiment 1. In the experiment 32, except that the film lower pressure P2 was set to 40 Pa, and the gas blowing pressure P0 was changed for this purpose, substantially the same conditions as in Experiment 1 were employed. Similarly, Experiment 33 was set to be substantially the same as Experiment 1 except that the film lower pressure P2 was set to 45 Pa, and the gas blowing pressure P0 was also changed for this purpose. The experimental results are shown in Table 2 below. From these experiments 31 to 33, it was found that the appropriate range of the sub-film pressure P2 was 5 Pa or more and 40 Pa or less.

(Experiment 41 ~ Experiment 43)

In the experiment 41 to the experiment 43, the lower air blowing head 50 of the experiment 1 was used, and the film vibration test and the external disturbance resistance test were carried out by changing the ratio (W2/P), and the appropriate range of the ratio (W2/P) was confirmed. In Experiment 41, the same conditions as in Experiment 1 were set except that the ratio (W2/P) was changed to 0.3. However, the ratio (W2/P) is changed but the floating height HF is set to be fixed, and thus the gas blowing pressure P0 or the pressure near the nozzle P1, the sub-film pressure P2, and the difference (P2-P1) are also changed. In the experiment 42, the same conditions as in Experiment 41 were set except that the ratio (W2/P) was changed to 0.4. Similarly, Experiment 43 was set to the same conditions as Experiment 41 except that the ratio (W2/P) was changed to 0.05. However, the ratio (W2/P) was changed in the same manner as in Experiment 41, but the floating height HF was set to be fixed, and thus the gas blowing pressure P0 or the pressure near the nozzle P1, the sub-membrane pressure P2, and the difference (P2-P1) also occurred. Changed. The experimental results are shown in Table 3 below. From the results of Experiment 1 and Experiment 41 to Experiment 43, the appropriate range of the ratio (W2/P) was 0.1 or more and 0.3 or less.

Further, an experiment for confirming an appropriate range of the pressure difference (P2-P1) between the pressure P1 near the nozzle and the pressure P2 under the membrane was not particularly performed. However, it was found from the results of the respective experiments that when the pressure difference (P2-P1) was 2 Pa or less, the film vibration or external disturbance was well tolerated.

30‧‧‧ Wet film

30a‧‧‧film surface

49‧‧‧ Dry air

50‧‧‧Air head

55‧‧‧Nozzle plate

55a‧‧・Nozzle surface

55b‧‧‧Blow out the hole

55c‧‧‧Installation edge

56‧‧‧floor

56a‧‧‧The central part of the film transport direction

56b‧‧‧Linking Department

57‧‧‧ side panels

57a‧‧‧ tube connector

58‧‧‧End board

60‧‧‧Air control exhaust

61‧‧‧Exhaust trough

62‧‧‧floor

63‧‧‧Baffle

64‧‧‧Guideboard

65‧‧‧Exhaust ditch

66‧‧‧Exhaust clearance

67‧‧‧ side panels

68‧‧‧Exhaust port

D1‧‧‧ diameter

H2‧‧‧ Height

HF‧‧‧Floating height

L1‧‧‧ length

P‧‧‧ spacing

W2‧‧‧ vent width

W3‧‧‧ opening width of the exhaust gap

W4‧‧·The width of the nozzle face

X‧‧‧ direction

θ 1‧‧‧ tilt angle

Claims (11)

A film floating device comprising: a blowing head having a nozzle surface, wherein the nozzle surface is disposed to face a film surface of a strip-shaped film, and a plurality of blowing holes for blowing a gas toward the film surface are disposed And a gas flow control exhaust portion disposed on the nozzle surface along a width direction of the film and configured to discharge gas from the blowing hole to a side of the film. The film floating device according to claim 1, wherein the nozzle face and the airflow control exhausting portion are alternately arranged in a conveying direction of the film. The film floating device according to claim 2, wherein the length of the nozzle surface in the conveying direction of the film is set to W4, and the airflow control row in the conveying direction of the film When the length of the gas portion is W2 and the pitch in the transport direction of the film of the air flow control exhaust portion is P, the ratio (W2/P) of the length W2 to the pitch P is 0.1 or more. 0.3 or less, wherein the pitch P = the length W2 + the length W4. The membrane floating device of claim 3, wherein: the airflow control exhaust portion includes an exhaust slot and an exhaust port, the exhaust slot comprising: a pair of partitions facing the membrane surface Projecting and being spaced apart from each other in the film transport direction; a pair of guide plates between the pair of baffles, from the projecting end of one of the baffles toward the base end of the other of the baffles Tiltly connected to the partition; and An exhaust gap is provided between the front ends of the pair of guide plates; the exhaust ports are open on both sides in the film width direction of the exhaust grooves. The film floating device of claim 4, comprising: a side plate that blocks both ends of the exhaust groove in the film width direction, and a vent hole formed in the side plate, and the vent hole The exhaust port is configured. The film floating device according to any one of claims 1 to 5, wherein a gas discharge pressure of the gas in the blowing hole is 30 Pa or more and 150 Pa or less, from the blowing hole to the The distance from the film is 20 mm or more and 100 mm or less. The film floating device according to claim 6, wherein the pressure at a position separated from the nozzle surface by 20 mm and the pressure at a position separated from the film surface by 5 mm are 5 Pa or more and 40 Pa or less. The film floating device according to claim 7, wherein a difference between a pressure at a position separated from the nozzle surface by 20 mm and a pressure at a position separated from the film surface by 5 mm is 2 Pa or less. A tenter comprising: the film lifting device according to any one of claims 1 to 8; and a film conveying device for holding both sides of the film by a holding portion And conveying the film by circulating the holding portion in a conveying direction of the film, the gas being a temperature-regulated dry for evaporating a solvent in the film Dry air. A solution film forming apparatus, comprising: a casting device, casting a strip-shaped cast film on a traveling annular support body after casting a dope comprising a polymer and a solvent, and casting the film The film is stripped from the support as a wet film; the tenter according to claim 9 holds and transports the wet film conveyed from the casting device; and a drying device The wet film conveyed by the tenter is dried. A solution film forming method, comprising: a casting step of casting a dope containing a polymer and a solvent onto a traveling annular support body to form a strip-shaped cast film, and then casting the film The film is peeled off from the support as a wet film; in the film transfer step, both sides of the wet film passing through the casting step are held by the holding portion, and the wet film is conveyed; and the tentering step, The drying gas is blown from the nozzle surface having the plurality of blowing holes toward the film surface of the wet film in the film transporting step by the air blowing head main body, whereby the wet film is dried, and the drying is utilized in the drying. An air flow control exhaust portion that is disposed in the transport direction of the wet film and that is disposed along the width direction of the wet film on the nozzle surface, and the dry gas that has hit the film surface is wetted The side of the film is discharged; and a drying step of drying the wet film through the tentering step.