JPH0671663A - Water film forming device in manufacture of resin film - Google Patents

Abstract

PURPOSE:To form a water film having a uniform thickness by applying wet air uniformly to the surface of a drum. CONSTITUTION:This is a device to form a water film on the surface of a casting drum by being provided on a manufacturing device of a resin film manufacturing a resin film by supplying a sheetlike molten resin on the drum and provided with a main body 24, a pipe 26 as a wet air spouting device and a wire net member 29. The main body 24 is capable of arranging in close vicinity to the surface of the drum and possesses a chamber 25 opening toward a surface side of the drum. The pipe 26 is for spouting the wet air against a chamber 25 of the main body 24. The wire net member 29 is arranged between the pipe 26 and an opening part of the chamber 25 of the main body 24 and for scattering of the wet air within the chamber 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water film forming apparatus,
In particular, the present invention relates to a water film forming apparatus used in a resin film manufacturing apparatus for manufacturing a resin film by supplying a sheet-shaped molten resin onto a rotating drum.

[0002]

2. Description of the Related Art As a method for producing a resin film at high speed, a thin film of water is formed on the surface of a rotating body (for example, a casting drum), and a molten resin is supplied to the surface of the casting drum through this water film. There is known a method for manufacturing. An apparatus for carrying out this type of manufacturing method generally includes a casting drum, a water film forming section for forming a water film on the surface of the casting drum, and a sheet-like melt on the casting drum on which the water film is formed. A resin supply unit for extruding the resin and a water film removal unit for removing the water film on the surface of the casting drum are provided.

In such an apparatus, since a water film is interposed between the resin film and the drum surface, the air accompanying the resin film is eliminated, and the generation of minute bubbles that are easily formed on the resin film surface is greatly generated. Can be suppressed to.
As a result, it is possible to significantly increase the production speed.

[0004]

In the conventional resin film manufacturing apparatus described above, the casting drum is cooled and the moist air is ejected from the water film forming portion. The moist air hits the surface of the casting drum to cause dew condensation, thereby forming a water film on the surface of the casting drum. At this time, it is important to form a uniform water film having a predetermined thickness on the surface of the casting drum. For example, when the thickness of the water film is locally thin, the surface tension of this part becomes strong, and when the manufactured resin film is separated from the casting drum, that part is difficult to peel off, and film breakage may occur. is there.

Therefore, when the moist air is ejected from the water film forming portion onto the surface of the casting drum, it is important that the moist air uniformly contacts over a predetermined area of the surface of the drum. An object of the present invention is to provide a water film forming apparatus for a resin film manufacturing apparatus capable of uniformly applying humid air to the drum surface to form a water film having a uniform thickness on the drum surface.

[0006]

A water film forming apparatus according to the present invention is provided in a resin film manufacturing apparatus for supplying a sheet-shaped molten resin onto a rotating drum to manufacture a resin film, and a water film is formed on the drum surface. It is an apparatus for forming a film.
The apparatus main body, the moist air jetting means, and the mesh member are provided.

The apparatus main body can be arranged close to the surface of the drum, and has a chamber that opens to the surface of the drum. The moist air ejecting means is means for ejecting moist air to the chamber of the apparatus body. The mesh member is a member that is arranged between the moist air jetting means and the opening of the chamber of the apparatus main body to diffuse the moist air into the chamber.

[0008]

In the water film forming apparatus of the resin film manufacturing apparatus according to the present invention, humid air is jetted into the room of the apparatus body. This moist air moves from the opening of the chamber of the apparatus body to the surface of the drum, and a mesh member having a predetermined opening ratio is provided, for example, at the outlet of the chamber between the ejection means and the opening of the chamber. . Therefore, the flow of the moist air to the drum side is once interrupted by the mesh member, and the moist air is uniformly diffused in the entire chamber in the axial direction of the drum and the direction intersecting with the axial direction. In this state, the moist air reaches the drum surface through the openings of the mesh member. For this reason, the moist air uniformly contacts the drum surface facing the chamber of the apparatus body,
A water film having a uniform thickness can be formed.

[0009]

EXAMPLE FIG. 1 shows a resin film manufacturing apparatus according to an example of the present invention. In the figure, the resin film manufacturing apparatus mainly includes a film manufacturing unit 1, a film stretching unit 2, and a winding unit 3. Film manufacturing department 1
Is a casting drum 4, a resin supplying device 5, a static electricity applying device 6, a water film forming device 7, three moist air generating devices 80 (only one is shown in the figure), and a film feeding device. 8 and.

The casting drum 4 is a cylindrical member having a smooth outer peripheral surface, and can be rotated counterclockwise by a driving device (not shown). Further, the casting drum 4 has a built-in cold water pipe (not shown) for circulating cooling water to cool the inner peripheral surface. The resin supply device 5 is provided above the casting drum 4 and has a die (not shown) extending parallel to the axis of the casting drum 4. From this die, a sheet-shaped molten resin 5a having a constant thickness can be supplied onto the casting drum 4.

The static electricity applying device 6 is arranged on the left side of the resin supply device 5 in the figure, and slightly apart from the outer peripheral surface of the casting drum 4. The static electricity applying device 6 has a static electricity applying wire 6 a extending parallel to the axis of the casting drum 4. The static electricity applying wire 6a includes
A voltage applying device (not shown) is connected and a high voltage can be applied.

The water film forming device 7 is arranged on the right side of the resin supply device 5 in the figure, and can be brought into and out of contact with the casting drum 4 by a retracting device 9. Here, FIG.
8 to FIG. 8, details of the water film forming device 7 and the retracting device 9 will be described. The water film forming device 7 includes a water film forming unit 19
And a water film removing unit 20 provided on the film feeding device 8 side of the water film forming unit 19 are integrally configured (FIG. 2). As shown in FIG. 3, the water film forming unit 19 includes a main moist air blowing device 21 and a pair of sub moist air blowing devices 22 and 22. The main moist air blowing device 21 is arranged parallel to the axis of the casting drum 4, and its length is set longer than that of the resin supply device 5 (FIG. 4). Main moist air blowing device 21
Has a U-shaped cross section and has a main body 24 made of an aluminum material in which a sheath heater 23 is cast. The main body 24 has a chamber 25 facing the casting drum 4, and the chamber 25 extends along the axis of the casting drum 4. The width D of the chamber 25 in the direction orthogonal to the axial direction of the casting drum 4 is 2
It is preferably 0 to 300 mm, more preferably 50 to 100 mm.
In this embodiment, the width D is set to 75 mm for the casting drum 4 having a diameter of 1 m.

A pipe 26 for ejecting moist air into the chamber 25 is arranged above the chamber 25. The lower half of the pipe 26 projects into the chamber 25, and small holes 26a for ejecting moist air are provided therein in a zigzag pattern with a predetermined pitch. Further, a flexible tube (not shown) from the humid air generator 80 is connected to one end of the pipe 626. A stainless steel wire mesh member 29 is arranged at the opening of the chamber 25. The wire mesh member has a wire diameter of 0.12 mm, a mesh of 80 mesh, and an aperture ratio of 39.3%. The wire mesh member 29 preferably has a mesh of 30 mesh or more and an aperture ratio of 30 to 50%. Further, the wire net member 29 may be formed of a resin mesh member or the like.

An edge member 28 made of an aluminum material is attached to the end of the main body 24 on the casting drum 4 side. The edge member 28 extends parallel to the axis of the casting drum 4, and the end surface on the casting drum 4 side is inclined corresponding to the surface shape of the casting drum 4. Further, a heat insulating material 27 such as glass fiber is arranged on the upper portion and both side portions of the main body 24.

The pair of sub-humid air blowing devices 22 are provided on the side of the resin feeding device 5 of the main moist air blowing device 21.
They are arranged at both ends of the main moist air blowing device 21 (see FIG. 4). The configuration of each sub-humid air blowing device 22 is
As shown in FIG. 3, the main humid air blowing device 21 is substantially the same as the main body 31 having the chamber 30, and the heat insulating material 32 provided on the upper part of the main body 31 and on the side opposite to the main humid air blowing device 21. An edge member 33 provided on the casting drum 4 side of the main body 31, a stainless steel wire net 34 provided at the opening of the chamber 30, and a flexible tube (not shown) from the humid air generator 80 are connected. And a pipe 35 for ejecting humid air. A sheath heater 36 is embedded in the main body 31.

As shown in FIG. 5, the water film removing unit 20 includes a nonwoven fabric roll 37, a bearing 38 for rotatably supporting the nonwoven fabric roll 37, and an air cylinder for pressing the nonwoven fabric roll 37 against the surface of the casting drum 4. And 39. The nonwoven fabric roll 37 extends parallel to the axis of the casting drum 4 (see FIG. 4). Also,
The nonwoven fabric roll 37 is covered with a cover (not shown) on the upper side thereof, and is connected to a flexible tube extending from the vacuum pump 67a (FIG. 1).

As shown in FIG. 6, pedestals 41 are fixed to both ends of the water film forming device 7 in the longitudinal direction. A flange portion 42 is provided on the side of the cradle 41 on the casting drum 4 side. Further, from the water film forming device 7, a pair of brackets 4 toward the retracting device 9 is provided.
3,43 are projected in parallel. Each bracket 43 is provided with a pin hole 43a.

The retracting device 9 is mainly composed of a moving part 9a and a docking device 60 (see FIG. 1; the docking device is not shown). Referring to FIGS. 2 and 6,
The details of the moving unit 9a will be described. The moving unit 9 a has a moving block 44 and a moving frame 45 fixed to the upper part of the moving block 44. Moving block 44
Is a pair of brackets 4 protruding from the water film forming device 7.
It is arranged between 3 and 43. And moving block 4
A pair of pins 54, 54 projecting from both ends of the pin 4 are fitted in the corresponding pin holes 43a, 43a of the bracket 43, whereby the moving block 44 supports the water film forming device 7. The pins 54, 54 are the moving blocks 4
The movable block 44 can be moved in and out by a cylinder (not shown) provided in the unit 4.

On the side end surface of the moving frame 45, two sets of moving rollers 46 are rotatably provided. The moving roller 46 is arranged on a horizontal guide rail 48 supported by a support frame 47, as shown in FIG. A moving air cylinder 49 is fixed to the support frame 47, and the moving frame 45 is supported by the rod tip 49a of the moving air cylinder 49. In the moving unit 9 a, the moving air cylinder 49 allows the moving frame 45 to reciprocate along the guide rails 48.

The docking device 60 is arranged at both ends of the casting drum 4, and is a fixed frame (not shown) for rotatably supporting the casting drum.
Is attached to. As shown in FIG. 7, the docking device 60 mainly includes an abutting portion 63 and an air cylinder 62 for moving the abutting portion 63 up and down. The contact portion 63 is formed in a shape with which the flange portion 42 of the water film forming device 7 can come into contact.

Retaining links 70 are rotatably attached to both ends of the contact portion 63, respectively. A clamp roller 71 is rotatably attached to the tip of each holding link 70, and a holding air cylinder 72 is attached to the other end.
Are connected. With such a docking device 60, the water film forming device 7 can take the retracted position shown by the alternate long and short dash line in FIG. 1 and the water film forming position adjacent to the casting drum 4. Here, the cylinder stroke of the lifting air cylinder 62 is such that the lower ends of the moist air blowing devices 21 and 22 are 50 mm or more from the surface of the casting drum 4 when the water film forming device 7 is moved to the retracted position. The edge members 28 and 33 shown in FIG. 3 have been set and have moved to the water film forming position.
The gap E between the tip of the and the surface of the casting drum 4 is 1 to
It is set to be 5 mm, preferably 1 to 3 mm. If the gap E exceeds 5 mm, the drum 4 may be used in the operation of forming a water film on the casting drum 4 (described later).
The humid air is prevented from reaching the casting drum 4 by the accompanying air flow, and a good water film forming operation cannot be performed.
The retracted position is 1 from the surface of the casting drum 4.
00 mm is desirable. The water film formation position is preferably set to 2 mm in order to form a uniform water film. Also,
The air flow rate of the air cylinder 62 is 0.1 at which the water film forming device 7 is moved between the retracted position and the water film formed position.
It is adjusted so that it can be set to m / s or higher. The moving speed is preferably 0.2 m / s.

As shown in FIG. 8, each moist air generator 80 has a closed container 81. As shown in FIG. 8, one end of a water supply pipe 82 for supplying water into the closed container 81 is arranged in the closed container 81. The water supply pipe 82 has a temperature raising tank 83 and a solenoid valve 84.
The temperature raising tank 83 is a heater 85 for warming the water inside.
have. A temperature sensor (not shown) is attached to the temperature raising tank 83.

An air supply pipe 86 is provided at the bottom of the closed container 81.
Are arranged. The air supply pipe 86 has a control valve 87, and compressed air having a constant pressure can be supplied from a compressed air supply device (not shown) such as a compressor. The air supply pipe 86 has a large number of small holes for ejecting compressed air in the closed container 81 (not shown). The small holes have a diameter of 5 mm or less (preferably 3 mm or less). Further, the closed container 81 has a heater 88 for warming water, a temperature sensor 89 for measuring the water temperature, and a liquid level sensor 90 for detecting the liquid level therein. The liquid level sensor 90 is
It is arranged at a height of 300 mm or more from the bottom surface of the closed container 81. The upper limit of the height of the liquid level sensor 90 is not particularly limited, but is normally regulated by the height of the closed container 81, which is limited in relation to other devices.

A moist air supply pipe 91 is attached to the upper part of the closed container 81. The humid air supply pipe 91 mainly includes a supply pipe main body 92 and a heater 93 for keeping heat. The supply pipe main body 92 has one end attached to the upper end of the closed container 81 and opens into the closed container 81. The supply pipe main body 92 extends upward from the closed container 81 and is bent so as to have an ascending slope in the middle. The other end is connected to the other end of the flexible tube for supplying the moist air to the moist air blowing device. The heater 93 is arranged so as to cover the outer peripheral portion of the supply pipe main body 92, and can be controlled by a temperature sensor (not shown).

The film feeding device 8 is mainly composed of a suction roll 10 and a pair of guide rolls 11 and 12. The suction roll 10 is arranged near the casting drum 4 and extends parallel to the axis of the casting drum 4. Further, the suction roll 10 can be rotated clockwise by a driving device (not shown). The suction roll 10 has a large number of suction holes on the roll surface and is connected to a vacuum pump 13. The pair of guide rolls 11 and 12 is arranged on the downstream side of the suction roll 10 and arranged in parallel with the suction roll 10.

The film stretching section 2 is arranged on the downstream side of the film manufacturing section 1, and has a vertical axis stretching section 14 and a horizontal axis stretching section 15 in this order. The vertical axis stretching section 14 is composed of a large number of rolls arranged in parallel, and can apply a tension in the transport direction to the resin film F from the film manufacturing section 1 to stretch the resin film F in the vertical axis direction. . The horizontal axis stretching portion 15 can grip the both side edges of the resin film F and perform stretching processing in the width direction.

The winding section 3 has a winding roll 16. A pair of guide rolls 1 for guiding the resin film F from the film stretching unit 2 to the winding roll 16 between the winding roll 16 and the film stretching unit 2.
7, 18 are arranged. Next, a method for manufacturing a biaxially stretched resin film by the resin film manufacturing apparatus will be described.

In the film manufacturing section 1, cooling water is supplied to the casting drum 4 so that the surface temperature of the drum is, for example, 2 ° C.
Set to 5 ° C. Then, by a drive device not shown,
Rotate the casting drum 4 counterclockwise. On the rotating casting drum 4, a resin supply device 5 is provided.
The sheet-shaped molten resin 5a is extruded from the die. When the molten resin 5a from the die contacts the surface of the casting drum 4, it is cooled and solidified to form a resin film F.
The resin film F is brought into close contact with the surface of the casting drum 4 by the static electricity applying device 6. Here, when a high voltage is applied to the static electricity applying wire 6a, the air in the vicinity of the static electricity applying device 6 is ionized, so the surface of the casting drum 4 is charged and the resin film F adheres.

The resin film F obtained on the casting drum 4 moves in accordance with the rotation of the casting drum 4, is separated from the casting drum 4, and is conveyed to the film feeding device 8. In the film feeding device 8, the resin film F from the casting drum 4 is
It comes into close contact with the surface of the suction roll 10 and is fed to the guide roll 11 by driving the suction roll 10.
Then, the resin film F is guided by the guide rolls 11 and 12 and conveyed to the film stretching section 2. Here, the resin film F is stretched in the vertical axis direction and the horizontal axis direction in the vertical axis stretching section 14 and the horizontal axis stretching section 15, respectively, to become a biaxially stretched resin film. The biaxially stretched resin film is conveyed to the winding section 3 and is guided by the guide rolls 17,
It is guided by 18 and wound up by the winding roll 16.

In the above manufacturing process, the resin film F
When the tip of the sheet passes through the vertical axis extending portion 14, a water film starts to be formed on the surface of the casting drum 4. Next, the operation of forming the water film will be described. First, the moving air cylinder 49 of the retracting device 9 is operated to move the moving block 44 from the position indicated by the solid line in FIG. 1 to the position indicated by the alternate long and short dash line. At this position, the tips of the edge members 28, 33 of the moist air blowing devices 21, 22 of the water film forming device 7 supported by the moving block 44 are separated from the surface of the casting drum 4 by about 100 mm.

In this state, when the air cylinders 62 for raising and lowering the docking devices 60, 60 arranged at both ends of the casting drum 4 are actuated and the rods thereof are projected, the contact portions 63 of the docking device 60 become wet. Film forming device 7
And moves to contact the flange portion 42 of the pedestal 41 of the water film forming device 7. At this time, the air cylinder 72 for holding the docking device 60 is activated, and the rod thereof is projected. As a result, the holding links 70 at both ends of the contact portion 63,
70 rotate respectively, and the clamp roller 7 at the tip thereof
The flange portion 42 of the water film forming apparatus 7 is abutted with the abutment portion 63 at one portion.
Pressing against and firmly connecting both.

As described above, when the docking operation of the docking device 60 and the water film forming device 7 is completed, the main humid air blowing device 21 and the sub-humid air blowing device 22,
The humid air generator 80 corresponding to No. 22 starts to supply the humid air. Here, the operation of supplying the humid air by the humid air generator 80 will be described first. In the water supply pipe 82 of the moist air generator 80, water is first stored in the temperature rising tank 83. The water stored in the temperature raising tank 83 is
It is heated by the heater 85. The water in the temperature raising tank 83 heated in this way is supplied to the water supply pipe 8 when the electromagnetic valve 84 is opened.
It is continuously supplied to the inside of the closed container 81 through the No. 2. As a result, in the closed container 81, water from the water supply pipe 82 is stored up to the height of the liquid level sensor 90. When the water level in the closed container 81 reaches the height of the liquid level sensor 90, the control valve 84 is operated according to the signal from the liquid level sensor 90.
Is closed, and the supply of water into the closed container 81 is stopped.
The water supplied into the closed container 81 may be ordinary drinking water, but ion-exchanged water is preferable. This is because a small hole (not shown) of the air supply pipe 86 is likely to be clogged with calcium contained in drinking water.

Water supply pipe 82 stored in a closed container 81
The water is heated by the heater 88 to a constant temperature in the range of 81 to 90 ° C. Here, the heater 88 is
It operates according to the signal from the temperature sensor 89 to keep the water temperature in the closed container constant. When the hot water in the closed container 81 is set to a constant temperature, compressed air having a constant pressure starts to be supplied into the air supply pipe 86 from a compressed air supply device (not shown). The gauge pressure is 1 when the compressed air is supplied.
It is preferably set to 7 to 30 l / min in the range of to 5 kgf / cm ² . This compressed air is controlled by the control valve 8
When 7 is opened, it spouts into warm water from a small hole (not shown). The jetted air rises in the hot water and absorbs moisture to become moist air, which is stored in the upper portion of the closed container 81. Here, since the hole diameter of the small holes of the air supply pipe 86 is set within the above range, the air from the air supply pipe 86 becomes fine bubbles and rises in the warm water. Further, since the depth of the warm water is set within the above range, the retention time of air in the warm water is sufficiently secured. Further, since the water temperature of the air in the warm water is set within the above temperature range, the air efficiently absorbs moisture. For this reason, the air from the air supply pipe 86 becomes stable and stable moist air and is stored in the upper portion of the closed container 81.

The moist air stored in the upper part of the airtight container 81 is supplied to the corresponding moist air blowing device through the moist air supply pipe 91. Here, the moist air rises in the supply pipe main body 92 and is supplied to the moist air blowing device via the flexible tube. The moist air in the supply pipe body 92 is kept warm by the heater 93. Therefore, the humid air is prevented from condensing in the supply pipe main body 92.
Further, even if it is condensed in the supply pipe main body 92, since the supply pipe main body 92 has an ascending slope, the condensed water can be stored in the closed container 81.
Return to inside. As a result, the moist air having a constant water content can be stably supplied to the water film forming device 7.

When the hot water in the closed container 81 decreases and the liquid level decreases, the liquid level sensor 90 operates and the electromagnetic valve 84 opens, and water is supplied from the water supply pipe 82. The water supplied here is preheated in the temperature raising tank 83 to the temperature of the hot water stored in the closed container 81. In this way, even if new hot water is supplied into the closed container 81, the temperature of the hot water in the closed container 81 is unlikely to change. As a result, the moist air generator 80 can continue to stably supply the moist air having a constant humidity.

The moist air supplied to the water film forming device 7 is
Main moist air blowing device 21 and sub moist air blowing device 2
It is supplied into the pipes 26 and 35 of 2, 22 and is discharged into the respective chambers 25 and 30. Here, the main body 24, 31 of each moist air blowing device 21, 22 is connected to the sheath heater 2.
Preheat with 3,36. In this way, the moist air will not condense in the pipes 26, 35 and will not be condensed in the chamber 2.
It is discharged into 5, 30. The moist air discharged from the pipes 26 and 35 is fed to the outlet portions of the chambers 25 and 30 by the wire mesh member 2.
Due to the arrangement of 9, 34, they can be evenly distributed in the chambers 25, 30. Since the water film forming device 7 is sufficiently separated from the surface of the casting drum 4 as described above, it is difficult for the moist air from the moist air blowing devices 21 and 22 to reach the surface of the casting drum 4. Therefore, on the surface of the casting drum 4, dew condensation due to the moist air leaking from the moist air blowing devices 21 and 22 is unlikely to occur.

Next, when the moist air has sufficiently diffused into the chambers 25 and 30 of the main moist air blowing device 21 and the sub moist air blowing devices 22 and 22, the water film forming device 7 is shown by a chain line in FIG. Move from the position to the position indicated by the solid line. Here, in the moving block 44, the pin 54 is moved into the moving block 44 by a cylinder for pin operation (not shown) and pulled out from the pin hole 43 a of the bracket 43. As a result, the support of the water film forming device 7 by the moving block 44 is released. Next, when the lifting air cylinder 62 of each docking device 60 is operated to retract the rod, the water film forming device 7 moves away from the moving block 44, and the water film forming position close to the surface of the casting drum 4 is formed. Move to. At this time, the air cylinder 6 for lifting and lowering
The air supply amount of 2 is 0.2 when the moving speed of the water film forming device 7 is 0.2.
Since it is set to be m / s, the moist air blowing devices 21 and 22 rapidly approach the surface of the casting drum 4. At this water film forming position, the gap E (FIG. 3) between the lower ends of the edge members 28 and 33 of the moist air blowing devices 21 and 22 and the surface of the casting drum 4 is 2 mm.

In this state, the moist air blowing devices 21, 2
The moist air supplied from the second chambers 25 and 30 through the stainless wire nets 29 and 34 onto the casting drum 4 is cooled by touching the casting drum 4 and dew forms a water film. At this time, each moist air blowing device 2
Since the gap between the lower ends of 1 and 22 and the surface of the casting drum 4 is set to about 2 mm, a uniform water film is formed on the surface of the casting drum 4. Further, when the moist air blowing devices 21 and 22 are brought closer to the surface of the casting drum 4, the air cylinder 62 makes the moist air blowing devices 21 and 22 come closer to each other at a moving speed of 0.2 m / s at a high speed. It is possible to clarify the boundary between the part where the film is not formed and the part where it is formed,
It is possible to suppress unevenness in the thickness of the water film.

Further, although a water film is continuously formed on the surface of the casting drum 4, the width of the opening of the chamber 25 of the main moist air blowing device 21 is not less than the film length in the axial direction.
Moreover, since it is set to 75 mm in the direction intersecting with it, the moist air also contacts the rotating casting drum 4 for a sufficient time, and a more uniform water film can be formed. In addition, at both ends of the water film formed by the main moist air blowing device 21, the sub moist air blowing device 22 is provided.
A water film is formed by overlapping. For this reason, the water film on the casting drum 4 is prevented from drying at both end portions, so that the central portion and both end portions have a uniform thickness.

The water film arranged on the surface of the casting drum 4 eliminates the air that flows with the molten resin 5a from the die and flows into the contact portion with the casting drum 4. As a result, the adhesion between the resin film F and the casting drum 4 is further improved, so that the casting drum 4
Then, the resin film F can be produced at a higher speed. In the casting drum 4 after the resin film F is peeled off,
The water film disposed between the casting drum 4 and the resin film F remains as water drops. This water drop
The water moves to the water film forming device 7 as the casting drum 4 rotates, and is removed by the nonwoven fabric roll 37 in the water film forming device 7. Here, the non-woven fabric roll 37 is pressed against the surface of the casting drum 4 by the air cylinder 39 to rotate, and absorbs the water film on the surface of the casting drum 4. The water absorbed by the non-woven fabric roll 37 is sucked and removed by the vacuum pump 67a.

On the surface of the casting drum 4 from which water droplets have been removed by the nonwoven fabric roll 37, a water film is formed again by the moist air blowing devices 21 and 22. At this time, since the water film is removed by the non-woven fabric roll 37 as described above, a uniform water film with less uneven thickness can be formed.
For this reason, in the film manufacturing section 1, the adhesiveness between the resin film F and the casting drum 4 can be favorably maintained, so that film breakage due to uneven peeling of the resin film F is unlikely to occur, and the resin film F can be continuously produced at high speed.

[0042]

As described above, in the present invention, since the mesh member is provided at the outlet of the moist air and the moist air is once sufficiently diffused in the room, a uniform water film can be formed on the drum surface. The peeling performance when the film is separated from the drum can be improved.

[Brief description of drawings]

FIG. 1 is a schematic front view of a resin film manufacturing apparatus to which an embodiment of the present invention is applied.

FIG. 2 is a front view of a retracting device portion of the resin film manufacturing apparatus.

FIG. 3 is a schematic vertical cross-sectional view of a water film forming portion of the above embodiment.

FIG. 4 is a schematic plan view of a casting drum portion of the resin film manufacturing apparatus.

FIG. 5 is a schematic view of a water film removing unit of the above embodiment.

FIG. 6 is a perspective partial view of a connecting portion between the retracting device and the water film forming portion.

FIG. 7 is a schematic view of a docking device portion of the retracting device.

FIG. 8 is a schematic configuration diagram of a moist air generating device portion of the embodiment.

[Explanation of symbols]

 4 Casting Drum 5 Resin Supply Device 21 Main Wet Air Blowing Device 22 Sub Wet Air Blowing Device 24,31 Main Body 25,30 Chamber 26,35 Pipe 29,34 Wire Mesh Member

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[Procedure amendment]

[Submission date] November 12, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kunihiko Onishi 1-1-1, Sonoyama, Otsu City, Shiga Toray Co., Ltd. Shiga Plant

Claims (1)

[Claims] 1. A water film forming apparatus for forming a water film on the surface of a drum in a resin film manufacturing apparatus for manufacturing a resin film by supplying a sheet-shaped molten resin onto a rotating drum. An apparatus main body that can be arranged close to the drum surface and has a chamber that opens to the drum surface side; a moist air ejection unit for ejecting moist air to the chamber of the apparatus main body; and the moist air ejection unit. A water film forming apparatus for a resin film manufacturing apparatus, comprising: a mesh member that is disposed between the opening of the chamber of the apparatus body and diffuses moist air into the chamber.