JPH07137115A - Manufacture of resin film and device therefor - Google Patents

Abstract

PURPOSE:To remove moisture remaining on a resin film after the resin film is peeled from a casting drum out of water screens formed by a water screen forming device. CONSTITUTION:A device comprises a casting drum 4, a water screen forming device 7, a resin supplying device 5, and a moisture removing device 100. After a sheet-like melting resin is peeled from the drum 4, moisture remaining on the surface of the sheet-like melting resin is removed by the moisture removing device 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a resin film and an apparatus therefor, and more particularly, to a rotating body (for example, a casting drum) used when producing a resin film.
TECHNICAL FIELD The present invention relates to a method for manufacturing a resin film having a water film forming device for forming a water film on a substrate and an apparatus therefor.

[0002]

2. Description of the Related Art As a method for producing a resin film at a high speed, there is known a method of forming a thin film of water on the surface of a casting drum and casting a molten resin on the water film. An apparatus for carrying out this type of manufacturing method generally includes a casting drum, a water film forming unit for forming a water film on the surface of the casting drum, and a sheet-like member on the casting drum on which the water film is formed. A resin supply unit for extruding the molten resin and a water film removal unit for removing the water film on the surface of the casting drum are provided.

As a water film forming apparatus for such a resin film manufacturing apparatus, Japanese Patent Laid-Open No. 1-280527 discloses a water film forming section for a drum and a water film removing section for a drum, in which a large number of nonwoven fabrics are superposed. With a roll of

By thus interposing the water film between the resin sheet and the drum surface, the air accompanying the resin sheet is eliminated by the water film, and the generation of minute bubbles that are easily formed on the surface of the resin sheet is greatly increased. Can be suppressed to. As a result, it is possible to significantly increase the production speed.

[0005]

In the above-mentioned conventional resin film manufacturing apparatus, the sheet-shaped molten resin is supplied by the resin supply unit onto the casting drum having the water film formed on the surface by the water film formation unit, A resin film is molded on the casting drum. The resin film is peeled from the casting drum at an appropriate position. Among the water films formed by the water film forming section, the water film remaining on the surface of the casting drum is the water film arranged on the casting drum. It is removed by the removal unit. However, the water film (moisture) formed by the water film forming part remains on the surface of the resin film peeled off from the casting drum, and when the resin film advances to the film stretching part in the next process while the water remains. Is
It becomes a film defect.

The object of the present invention is to remove the water remaining on the resin film after the resin film is peeled off from the casting drum in the water film formed by the water film forming section, and to always improve the quality of the resin film. It is an object of the present invention to provide a method for producing a resin film that can be maintained and an apparatus for the same.

[0007]

According to the method for producing a resin film of the present invention which meets the above object, water is formed on a surface of a rotatable drum by a water film forming device provided at predetermined intervals on the surface of the rotatable drum. A water film is applied to form a water film, and a sheet-shaped molten resin is provided on the drum having the water film formed, from a resin supply device provided on the downstream side of the water film forming device and above the drum surface. Is a method for producing a resin film by continuously supplying a resin film, wherein after the sheet-shaped synthetic resin film is peeled from the drum surface, at least water remaining on the surface of the resin film is removed. The method comprises sucking and removing with a suction means.

In the resin film manufacturing apparatus according to the present invention, the water film forming apparatus for forming a water film on the drum surface can be arranged so as to face the drum surface with a predetermined gap, and the water film forming apparatus. A resin supply device for supplying a sheet-shaped molten resin onto the drum having a water film formed on its surface by a forming device, and the sheet-shaped molten resin after the sheet-shaped molten resin is separated from the drum. And a water removing device for removing water remaining on the surface.

As the water removing device, for example, a suction roll formed by superposing a plurality of nonwoven fabrics, an air suction means,
Alternatively, it is composed of air suction means and air blowing means.

[0010]

In the method and apparatus for manufacturing a resin film according to the present invention, since the water removing device is arranged after the resin film is separated from the drum during film manufacturing, the water formed by the water film forming device is disposed. Out of the membrane
Water remaining on the surface of the resin film after being peeled off from the drum can be removed, and the resin film can be manufactured without deteriorating the quality of the film.

[0011]

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 is mainly composed of a film manufacturing section 1, a film stretching section 2 and a winding section 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 is 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 composed of a die which is arranged above the casting drum 4 and has a slit-shaped discharge port (not shown) extending parallel to the axis of the casting drum 4. From this mouthpiece, a sheet-shaped molten resin 5a having a constant thickness is 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. A voltage applying device (not shown) is connected to the static electricity applying wire 6a, and a high voltage is 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.

Details of the water film forming device 7 and the retracting device 9 will now be described with reference to FIGS. 2 to 8. The water film forming device 7 includes a water film forming part 19 and a water film removing part 2 provided on the film feeding device 8 (shown in FIG. 1) side of the water film forming part 19.
It is configured as a unit that integrally includes 0 and 0 (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-humid air blowing devices 22 provided at positions corresponding to both ends of the main moist air blowing device 21. 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
The thickness 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 formed in a zigzag pattern at a predetermined pitch. Further, a flexible tube (not shown) from the humid air generator 80 is connected to one end of the pipe 26. A stainless steel wire mesh member 29 is arranged at the opening of the chamber 25. The wire mesh member 29 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. A heat insulating material 27 made of glass fiber or the like 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 at 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 moist air generator 80.
A pipe 35 having a small hole 35a for ejecting moist air, to which a flexible tube (not shown) from (described later) is connected. A sheath heater 36 is embedded in the main body 31.

As shown in FIG. 5, the water film removing section 20 includes a non-woven fabric roll 37 formed by stacking a plurality of non-woven fabrics, a bearing 38 for rotatably supporting the non-woven fabric roll 37, and the non-woven fabric roll 37 on the casting drum 4. It has an air cylinder 39 for pressing against the surface. The nonwoven fabric roll 37 extends parallel to the axis of the casting drum 4 (see FIG. 4). The non-woven fabric roll 37 is covered with a cover (not shown) at its upper portion and is connected to a flexible tube 67 extending from the vacuum pump 67a.

As shown in FIG. 4, the roll width of the non-woven fabric roll 37 is such that the dimension L from each end face of the moist air blowing devices 21, 22 is 10 mm or more in the direction along the rotation axis of the drum. If set, moist air blowing device 2
Even if the moist air supplied from the Nos. 1 and 22 onto the casting drum 4 is diffused to some extent and the water film formed by the width of the moist air blowing devices 21 and 22 becomes slightly wider, the water film is uniformly removed over the entire width. can do.

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. Flange part 42
The main moist air hole 50, each sub-humid air hole 51, 5
1. A water film removing hole 52 is provided. The main moist air hole 50 is connected to one end of the pipe 26 (not shown), and the sub moist air holes 51 and 51 are connected to the pipes 35 and 3, respectively.
5 is connected to one end (not shown). Further, the water film removing hole 52 is connected to one end of the nonwoven fabric roll 37 (not shown). In addition, a pair of brackets 43, 43 project in parallel from the water film forming device 7 toward the retracting device 9. 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 shown in detail in FIG. 7). Figure 2
Also, the details of the moving unit 9a will be described with reference to FIG. The moving unit 9a includes the moving block 44 and the moving block 4
4 and a moving frame 45 fixed to the upper part of the frame 4.

The moving block 44 is arranged between a pair of brackets 43, 43 protruding from the water film forming device 7. Then, a pair of pins 54, 54 protruding from both ends of the moving block 44 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. . In addition, pin 5
The cylinders 4 and 54 can be moved in and out of the moving block 44 by a cylinder (not shown) provided in the moving block 44.

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 attached to a fixed frame (not shown) for rotatably supporting the casting drum 4.

As shown in FIG. 7, the docking device 60 is mainly composed of an abutting portion 63 and an air cylinder 62 for raising and lowering the abutting portion 63. Abutting portion 63
Is formed in a shape with which the flange portion 42 of the water film forming device 7 can abut.

When the flange 42 abuts on the abutting portion 63, the moist air is provided at a position corresponding to the main humid air hole 50 and the sub humid air holes 51, 51 shown in FIG. Flexible tubes 77, 78, 7 from generator 80
8 are connected. And flexible tube 7
Sealing portions 73, 74, 74 made of silicon or the like are provided at one ends of 7, 78, 78. When the abutting portion 63 and the flange portion 42 abut, the sealing portion 7 is formed.
By pressing and deforming 3, 74, 74, the path for moist air is connected without leaking. Similarly, the water film removing hole 52
A flexible tube (not shown) from the vacuum pump 67a is connected to a position corresponding to the above, and a sealing material (not shown) made of silicon or the like is provided at one end of the flexible tube. . Therefore, when the contact portion 63 and the flange portion 42 contact each other, the path of the air sucked when removing the water film is connected without leaking.

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 shown by the solid line in the vicinity of the casting drum 4. There is. 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 member 28 shown in FIG. 3 has been set and has moved to the water film forming position.
Gap E between the tip surface of 33 and the surface of the casting drum 4
Is 5 mm or less, preferably 1 to 3 mm. When the gap E exceeds 5 mm, in the operation of forming a water film on the casting drum 4, the accompanying airflow of the drum 4 hinders the moist air from reaching the casting drum 4, 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 or more is desirable. The water film formation position is preferably set to 2 mm in order to form a uniform water film. The air flow rate of the air cylinder 62 is adjusted so that the speed at which the water film forming device 7 is moved between the retracted position and the water film forming position can be set to 0.1 m / sec or more. The moving speed is preferably 0.2 m / sec.

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

At the bottom of the closed container 81, an air supply pipe 86
Are arranged. The air supply pipe 86 has a control valve 87, and compressed air having a constant pressure is supplied from a compressed air supply device (not shown) such as a compressor. The air supply pipe 86 is provided in the closed container 81.
It has a large number of small holes (not shown) for ejecting compressed air. The small holes have a diameter of 5 mm or less (preferably 3 mm or less). Furthermore, the closed container 81
Has a heater 88 for warming the water, a temperature sensor 89 for measuring the water temperature, and a liquid level sensor 90 for detecting the liquid level inside. The liquid level sensor 90 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. One end of the supply pipe main body 92 is connected to the upper end of the closed container 81 and opens inside 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 upward 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 the temperature is 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.

In this embodiment, a water removing device 100 is provided on the suction roll 10 for removing the water remaining on the resin film F after being peeled off from the casting drum 4.

Although the water removing device 100 is arranged above the suction roll 10 in FIG. 1, the position of arrangement is not particularly limited, and the space between the resin film peeled from the casting drum 4 and the film stretching portion 2 is not limited. In addition, it may be arranged on the surface side of the resin film which is in contact with the casting drum 4.

As one embodiment of the water removing device 100,
Nonwoven fabric roll 111 formed by stacking a number of nonwoven fabrics on FIG.
1 shows a suction roll composed of It has a non-woven fabric roll 111, a bearing portion 112 that rotatably supports the non-woven fabric roll 111, and an air cylinder 113 for pressing the non-woven fabric roll 111 against the surface of the suction roll 10. Roll width (face length) of the nonwoven fabric roll 111
May be larger than the film width, but may be smaller than the film width when the water film (moisture) is sufficiently dried at the film edge or the like. The nonwoven fabric roll 111 is a vacuum pump 115.
Is connected to a flexible tube 114 extending from.

10 and 11 show a water removing device 1
00 another embodiment is shown. In FIG. 10, air suction means 120 is arranged instead of the nonwoven fabric roll 111.
Further, FIG. 11 shows an arrangement in which an air blowing means 121 is arranged in addition to the air suction means 120. Air suction means 1
Flexible tubes extending from the blower are connected to the air blower 20 and the air blowing means 121 (not shown).

The film stretching section 2 is arranged on the downstream side of the film manufacturing section 1, and has a longitudinal stretching section 14 and a lateral stretching section 1.
And 5 in this order. The longitudinal stretching section 14 is composed of a number of rolls arranged in parallel, and applies tension in the transport direction to the resin film F from the film manufacturing section 1 to stretch the resin film F in the longitudinal direction (longitudinal direction). To do. The lateral stretching section 15 grips both side edges of the resin film F and performs a stretching process 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 of manufacturing a biaxially stretched resin film by the above resin film manufacturing apparatus will be described. In the film manufacturing section 1, cooling water is supplied to the casting drum 4 and the surface temperature of the drum is set to 25 ° C., for example.
Then, the casting drum 4 is rotated counterclockwise by a driving device (not shown).

On the rotating casting drum 4,
The sheet-shaped molten resin 5a is extruded from the die of the resin supply device 5. When the molten resin 5a from the die comes into contact with the surface of the casting drum 4, the molten resin 5a 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 as the casting drum 4 rotates, and is separated from the casting drum 4 and conveyed to the film feeding device 8. In the film feeding device 8, the resin film F from the casting drum 4 is brought into close contact with the surface of the suction roll 10 and the suction roll 10
Is fed to the guide roll 11. 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 longitudinal direction and the transverse direction in the longitudinal stretching portion 14 and the transverse stretching portion 15, respectively, to become a biaxially stretched resin film. The biaxially stretched resin film is conveyed to the winding unit 3, guided by guide rolls 17 and 18 and wound up by the winding roll 16.

In the above manufacturing process, at the start of manufacturing,
When the front end of the resin film F passes through the vertical stretched portion 14, it starts to form a water film on the surface of the casting drum 4. The operation of forming the water film will be described.

First, the water film forming apparatus 7 is located at a position away from the retracted position by a predetermined distance, and at the position, a work for removing foreign matters and the like adhering to the water film forming apparatus 7 before the water film forming operation. The position is also a position for performing work such as parts replacement. Then, when starting the operation of forming the water film, the moving air cylinder 49 of the moving portion 9a of the retracting device 9 is operated as the transfer means to move the moving block 44 from the position shown by the solid line in FIG. Move it to the position shown. In this case, first, the casting drum 4 needs to be moved to a predetermined position by an elevating device (not shown). At this position, the tip ends 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 way, by providing the moving unit 9a in the retraction device 9 as the transfer means, the water film forming operation start preparation position is changed from the maintenance work position to the water film forming device 7 required before the water film formation. The water film forming device 7 can be easily moved to the retracted position in a short time. Therefore, the actual productivity of the film can be favorably maintained.

In this state, when the air cylinders 62 for raising and lowering the docking devices 60 disposed at both ends of the casting drum 4 are operated to project the rods thereof, the abutting portions 63 of the docking device 60 are exposed to water. 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. And the seal part 7
By pressing and deforming 3, 74, 74, the connection between each moist air generating device 80, the main moist air blowing device 21, and the pair of sub moist air blowing devices 22 is completed. Similarly, the seal portion (not shown) at one end of the flexible tube from the vacuum pump 67a is also pressed and deformed, so that the vacuum pump 67a
The connection between a and the nonwoven fabric roll 37 is completed. As described above, the docking device 6 is used as the moving means of the water film forming device 7.
By providing 0, it becomes possible to hold the water film forming device 7 in the retracted position which is the start preparation position for water film formation, and further, the contact portion 63 of the docking device 60 is provided with a moist air pipe connecting mechanism. The seal portion 7 is attached to one end of the flexible tubes 77, 78, 78 from the humid air generator 80.
By providing 3, 74, 74, each moist air generator 8
0, the main humid air blowing device 21 and the pair of sub-humid air blowing devices 22 can be easily connected in a short time, and the productivity can be improved. Further, since the humid air pipe is generally kept at a high temperature, by providing the humid air pipe connecting mechanism, it is possible to maintain safety without manual work.

In the moving block 44, the pin 54 is moved into the moving block 44 by a pin operating cylinder (not shown) to move the pin 54 into the pin hole 43 of the bracket 43.
Extract from a. As a result, the support of the water film forming device 7 by the moving block 44 is released. When the moving air cylinder 49 is operated to retract the rod,
The moving block 44 returns to a position separated from the retracted position by a predetermined distance.

When the transfer operation of the water film forming device 7 to the docking device 60 is completed as described above, the main humid air blowing device 21 and the sub-humid air blowing devices 22, 22 are next.
The humid air generator 80 starts to supply the humid air.

Here, the operation of supplying the moist air by the moist 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 surface in the closed container 81 reaches the height of the liquid level sensor 90, the electromagnetic valve 84 is closed according to the signal from the liquid level sensor 90, 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 amount of compressed air supplied is such that the gauge pressure is 1 to 5 kgf / c.
It is preferably set to 7 to 30 liters / minute in the range of m ² . When the control valve 87 is opened, this compressed air is jetted into the 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 a rising slope, the condensed water is not sealed.
Go back to 1. As a result, 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 discharged into the chambers 25 and 30, respectively. 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 enter the chamber 2.
It is discharged into 5, 30. The moist air discharged from the pipes 26 and 35 is discharged 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, the moist air from the moist air blowing devices 21 and 22 hardly reaches 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 the one-dot chain line in FIG. Move from the position to the position indicated by the solid line. Here, the lifting air cylinder 62 of each docking device 60 is used.
When the rod is retracted by operating the water film forming device 7,
Moves from the retracted position to a water film forming position near the surface of the casting drum 4. At this time, the air supply amount of the lifting air cylinder 62 is set so that the moving speed of the water film forming device 7 becomes 0.2 m / sec, so that the moist air blowing devices 21 and 22 rapidly move. It approaches 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, 33 of the moist air blowing devices 21, 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 chambers 25 and 30 of No. 2 through the metal nets 29 and 34 made of stainless steel onto the casting drum 4 is cooled by touching the casting drum 4 to form a water film by dew condensation. At this time, each moist air blowing device 2
Since the gap between the lower ends of Nos. 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 high moving speed of 0.2 m / sec. The boundary between the part where the water film is not formed and the part where the water film is formed can be clarified, and the uneven thickness of the water film can be suppressed.

A water film is continuously formed on the surface of the casting drum 4, but 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.
In addition, 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, and 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 flowing along with the molten resin 5a from the die and flowing 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.

On the casting drum 4 after the resin film F has been peeled off, the water film arranged between the casting drum 4 and the resin film F remains as water drops. The water droplets move toward the water film forming device 7 as the casting drum 4 rotates, and are 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. Since this non-woven fabric roll 37 is formed by stacking a large number of non-woven fabrics,
Water is absorbed very efficiently by the capillary phenomenon and further by the suction force of the vacuum pump 67a. The water absorbed by the non-woven fabric roll 37 is absorbed by the flexible tube 6
A vacuum pump 67a sucks and removes the gas through the nozzle 7.

On the surface of the casting drum 4 from which water drops have been removed by the nonwoven fabric roll 37, a water film is again formed 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.
Therefore, in the film manufacturing section 1, since the adhesion between the resin film F and the casting drum 4 can be maintained well, 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.

On the other hand, the water remaining on the resin film F separated from the casting drum 4 is removed by the water removing device 11
Removed by zero. Therefore, even if the temperature of the resin film F is raised in the film stretching section 2 in the next step, a high quality resin film F can be produced without causing a film defect.

In the above embodiment, the nonwoven fabric roll 111 is used.
In the above, the non-driving roll is shown, but it may be driven and may be controlled by providing a film speed and a speed difference in some cases. Further, although the structure in which the water removing device 110 is separately provided is shown, the present invention is not necessarily limited to this, and the water remaining on the resin film may be removed by using the guide roll 11 as a suction roll, for example. The position of the air suction means 120 is not particularly limited, but it is preferable that the air suction means 120 is arranged at a distance of 0 to 5 mm above the resin film.

Further, the air blowing means 121 is also more effective if hot air is used as the blowing air. When the water remaining on the surface of the resin film F is small, the air sucking means 120 is not used and the air blowing means 121 alone is used. It is also effective when used in. The air blowing direction of the air blowing means 121 is not particularly limited, and may be appropriately adjusted according to the water content remaining in the resin film F.

[0063]

As described above, according to the present invention, after the resin film is peeled off from the casting drum, residual water on the surface of the resin film due to the water film forming device can be effectively removed, so that the occurrence of film defects is prevented. Therefore, a resin film of good quality can be manufactured.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a resin film manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of a retractor portion of the device of FIG.

FIG. 3 is an enlarged vertical cross-sectional view of a water film forming unit of the apparatus of FIG.

4 is an enlarged schematic plan view of a casting drum portion of FIG. 1. FIG.

5 is a schematic configuration diagram of a water film removal unit of the apparatus of FIG.

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

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

8 is a schematic configuration diagram of a moist air generating device portion used in the device of FIG. 1. FIG.

FIG. 9 is a schematic configuration diagram of a water removing device unit according to the embodiment.

FIG. 10 is a schematic configuration diagram showing another embodiment of the moisture removing device.

FIG. 11 is a schematic configuration diagram showing still another embodiment of the moisture removing device.

[Explanation of symbols]

 4 Casting Drum 5 Resin Supply Device 7 Water Film Forming Device 9a Moving Part 19 Water Film Forming Part 20 Water Film Removing Part 21 Main Wet Air Blowing Device 22 Sub Wet Air Blowing Device 37 Nonwoven Roll 60 Docking Device 110 Moisture Removing Device 111 Suction Roll Roll 120 as an air suction means 121 air blowing means

Claims (5)

[Claims] 1. A drum having a water film formed by applying water to the surface of the rotating drum from a water film forming device provided on the surface of a rotatable drum at a predetermined interval to form a water film. In the method for producing a resin film, a sheet-like molten resin is continuously supplied from a resin supply device provided on the upper side of the drum surface on the downstream side of the water film forming apparatus to produce a resin film. Then, after peeling the sheet-shaped synthetic resin film from the surface of the drum, water remaining on the surface of the resin film is sucked and removed by at least suction means to remove the resin film. . 2. A rotatable drum, a water film forming device which can be arranged to face the drum surface with a predetermined gap, and which forms a water film on the drum surface, and the water film forming device. A resin supply device for supplying a sheet-shaped molten resin onto the drum having a water film formed on the surface, and remaining on the sheet-shaped molten resin surface after the sheet-shaped molten resin is peeled from the drum And a water removing device for removing the remaining water. 3. The resin film manufacturing apparatus according to claim 2, wherein the water removing device is a suction roll formed by stacking a plurality of nonwoven fabrics. 4. The resin film manufacturing apparatus according to claim 2, wherein the water removing device is an air suction means. 5. The resin film manufacturing apparatus according to claim 2, wherein the moisture removing device comprises air suction means and air blowing means.