JP2000153548A - Method and apparatus for producing tubular film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the method and apparatus for producing tubular film capable of uniformizing the flow rate of cooling water around a mandrel. SOLUTION: In a tubular film producing method wherein a thermoplastic resin is melted and elasticized to be extruded downwardly from an annular die 2 to form a tubular film 7 and this tubular film 7 is guided to a mandrel to be cooled from the inside and outside thereof by cooling water to be solidified, a pipe for supplying water to the mandrel 4 in order to bring the inner surface of the tubular film 7 into direct contact with cooling water to cool the tubular film, a pipe for sucking used cooling water to discharge the same to the outside of the apparatus, a pipe for supplying air for expanding the film up to a required diameter and a pipe for discharging air are arranged in the mandrel 4 in a mutually concentric state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a tubular film and an apparatus for manufacturing a tubular film.

[0002]

2. Description of the Related Art Conventionally, as described in, for example, Japanese Patent Publication No. 39-2072, a tubular film of a thermoplastic resin is formed using an annular die and a mandrel, and the inside of the tubular film is formed. There is known a method for manufacturing a tubular film in which a tubular film is rapidly cooled by directly contacting cooling water.

In such a method for manufacturing a tubular film, a concave portion is provided on an upper peripheral surface of a mandrel, and cooling water is supplied to the concave portion by a water supply pipe. In addition, a concave portion is provided in the lower peripheral surface of the mandrel, a sponge is provided in the concave portion in contact with the inner surface of the tubular film, and water to be wiped by the sponge is drained by a drain pipe connected to a vacuum source. I have. An air supply pipe for sending air to the tubular film is provided in the mandrel.

[0004] Such a water supply pipe, a drain pipe, and an air supply pipe are arranged at positions away from the axis of the mandrel in the axial direction that does not interfere with each other.

[0005]

However, in the conventional method for manufacturing a tubular film, as described above, the water supply pipe, the drain pipe, and the air supply pipe do not interfere with each other at a position apart from the axis of the mandrel. Since it is arranged in the core direction, the flow path of the cooling water and air is not uniform depending on the position on the peripheral surface of the concave portion provided on the peripheral surface of the mandrel, and therefore, the cooling water especially between the mandrel and the tubular film. And the flow rate of the non-uniform film becomes non-uniform, which causes the non-uniformity of the cooling rate of the tubular film and the non-uniformity of the thickness of the tubular film.

Further, the flow path of the drainage from the sponge for absorbing and discharging the cooling water adhering to the tubular film to the drainage pipe is not circumferentially uniform. It was difficult to secure.

The present invention has been made in view of the problems in the method of manufacturing a tubular film described in the above-mentioned Japanese Patent Publication No. 39-2072 and the like. Manufacturing of a tubular film capable of solving the problems in the method of manufacturing a tubular film, making the flow rate of cooling water uniform around the mandrel, and uniformly supplying and discharging air into the tubular film. A method and an apparatus for manufacturing a tubular film.

[0008]

According to a first aspect of the present invention, there is provided a method of manufacturing a tubular film, the method comprising melt-plasticizing a thermoplastic resin and forming the tubular film downward from an annular die. In a method of manufacturing a tubular film, which is extruded into a mandrel and solidified by cooling with water from inside and outside of the tubular film, the inner surface of the tubular film is directly contacted with cooling water to cool the mandrel. A pipe for supplying water, a pipe for sucking used cooling water and discharging it to the outside of the apparatus, a pipe for supplying air for expanding the film to a required diameter, and a pipe for discharging the film are mutually concentric. It is characterized by being arranged in a shape.

Further, according to a second aspect of the present invention, there is provided an apparatus for manufacturing a tubular film, wherein a thermoplastic resin is melt-plasticized.
In a tubular film manufacturing apparatus in which a tubular film is extruded downward from an annular die, guided to a mandrel, and solidified by cooling with water from inside and outside of the tubular film, the inner surface of the tubular film is brought into direct contact with cooling water. Pipes for supplying water to the mandrel and pipes for sucking and discharging used water to the outside of the apparatus, and pipes for supplying air for expanding the film to a required diameter for cooling. Are arranged concentrically with each other.

According to a third aspect of the present invention, there is provided a method for manufacturing a tubular film according to the first aspect, wherein the cooling water is supplied directly to the inner surface of the tubular film. A porous annular body is provided on the upper surface, and cooling water supplied from a water supply pipe is supplied to the inner surface of the tubular film through the porous annular body.

According to a fourth aspect of the present invention, there is provided the tubular film manufacturing apparatus according to the second aspect, wherein the cooling water is supplied directly to the inner surface of the tubular film. Is provided, and cooling water supplied from a water supply pipe is supplied to the inner surface of the tubular film through the porous annular body.

According to a fifth aspect of the present invention, there is provided a method for manufacturing a tubular film according to the first aspect, wherein the cooling water attached to the inner surface of the tubular film is suctioned. A porous annular body is provided on the lower surface of the tubular film, cooling water attached to the surface of the tubular film is sucked through the porous annular body, and drained through a pipe provided inside the mandrel. .

According to a sixth aspect of the present invention, there is provided the tubular film manufacturing apparatus according to the first aspect of the present invention, wherein the water adhering to the inner surface of the tubular film is suctioned. A porous annular body is provided on the lower surface, water attached to the tubular film surface is sucked through the porous annular body, and drained through a pipe provided inside the mandrel, Is what you do.

In the present invention, the thermoplastic resin includes
Although not particularly limited, olefin homopolymers such as polyethylene, polypropylene, polybutene and polybutylene, etc., ethylene-propylene copolymer, olefins such as ethylene-butene copolymer and monomers copolymerizable therewith Or a mixture of these polymers and copolymers, such as polyolefin resin, vinyl chloride resin, nylon, etc., or a multilayered thermoplastic resin having different melting points between the surface layer and the core layer, or the core layer A thermoplastic resin having a gas barrier property is used as a material, and a multi-layered thermoplastic resin having a layer having an adhesive force between a surface layer such as a polyolefin can be used.

In the present invention, the thermoplastic resin may contain an inorganic filler, and if necessary, other additives such as an organic filler such as a plasticizer and a stabilizer. As the inorganic filler, calcium carbonate, calcium sulfate, calcium sulfite, calcium hydroxide and the like can be used. The addition amount of the inorganic filler to the thermoplastic resin is about 1 to 85% by weight, and when the addition amount is small, A thin film having excellent mechanical strength and a uniform thickness can be obtained. When the amount of addition is large, a porous thin film having a uniform thickness can be obtained.

In the present invention, the tubular film includes a film having a relatively large thickness, for example, a film having a thickness of several millimeters or more, in addition to a film having a normal thickness.

In the present invention, the material of the porous annular body is not particularly limited, but for example, metal, ceramic, synthetic resin and the like can be used. As the metal, a precipitation hardening stainless steel, a tool steel, a high-speed steel, or the like can be used. In addition, the porous holes need to have continuity. The pore size is not particularly limited, but is 10 to 1
Those having a size of about 00 μ can be used. Although the one having a small hole is effective for the permeation of air, the one having a relatively large hole diameter is preferable for the permeation of water from the viewpoint of increasing the amount of passing water. For example, a porous annular body having an outer diameter of 52 mmφ, a thickness of 4 mm, and a length of 20 mm can be a porous annular body for water supply having a pore diameter of 100 μm, and a porous annular body for absorbing water having a pore diameter of 42 μm can be used. .

Further, as a synthetic resin, high-temperature polyethylene or tetrafluoroethylene or the like does not melt even when heated, and is compression-molded in a temperature range in which the particle surface has tackiness.
The sintered state is maintained while leaving so-called holes. The pores can be formed by mixing a plasticizer or oil in a basic material such as a synthetic resin in advance, and then solidifying the resin, and then extracting the plasticizer or oil with a solvent to make the pores porous.

The ceramic is substantially the same as the metal and the synthetic resin, and the description is omitted.

In the method for producing a tubular film according to the present invention, the inner surface of the tubular film is cooled by bringing the inner surface of the tubular film into direct contact with cooling water.
A pipe for supplying water to the mandrel, a pipe for sucking used cooling water and discharging it out of the device, a pipe for supplying air for expanding the film to a required diameter, and a pipe for discharging the film. Since they are arranged concentrically with each other, the flow path of the cooling water and air becomes uniform, so that the flow rates of the cooling water and air become uniform, and the uniformity of the cooling rate of the tubular film and, consequently, the tubular film. Uniformity of thickness can be ensured.

In the apparatus for manufacturing a tubular film according to the second aspect of the present invention, a pipe for supplying water to a mandrel and a used pipe are used for cooling the tubular film by bringing the inner surface of the tubular film into direct contact with cooling water. Since the pipe for sucking water and discharging it to the outside of the apparatus and the pipe for supplying air for expanding the film to a required diameter and the pipe for discharging are arranged concentrically with each other, The flow path of the cooling water or the air becomes uniform, the flow rate of the cooling water becomes uniform, and the uniformity of the cooling rate of the tubular film and the uniformity of the thickness of the tubular film can be ensured.

In the method for manufacturing a tubular film according to the third aspect of the present invention, a porous annular body is provided on the upper surface of the mandrel to supply cooling water directly to the inner surface of the tubular film. Since the cooling water supplied from the pipe for supply is supplied to the inner surface of the tubular film through the porous annular body, a large number of water flows, though little by little, from the large number of holes on the wide surface of the porous annular body. The porous film is uniformly jetted from the wide surface, and the tubular film can be cooled uniformly.

In the apparatus for manufacturing a tubular film according to the present invention, a porous annular body is provided on the surface of the mandrel to supply cooling water directly to the inner surface of the tubular film. Since the cooling water supplied from the pipe is supplied to the inner surface of the tubular film through the porous annular body, a large number of water flows, though little by little, from the large number of holes on the wide surface of the porous annular body. The porous film is uniformly jetted from the wide surface, and the tubular film can be cooled uniformly.

In the method of manufacturing a tubular film according to the present invention, a porous annular body is provided on a lower surface of the mandrel to suck cooling water attached to an inner surface of the tubular film. Since the cooling water attached to the surface of the tubular film is sucked through the porous annular body and drained through a pipe provided inside the mandrel, water is absorbed in a large area in contact with the tubular film of the porous annular body. Is performed without the tubular film being strongly sucked into the mandrel,
This has an advantage that the resistance is not large when the tubular film is taken off.

Further, in the tubular film manufacturing apparatus according to the present invention, a porous annular body is provided on the lower surface of the mandrel for sucking cooling water attached to the inner surface of the tubular film. Since the cooling water adhering to the surface of the tubular film is sucked through the porous annular body and drained through a pipe provided inside the mandrel, a large area in contact with the tubular film of the porous annular body is provided. Water absorption is performed in the area, the tubular film is not strongly sucked by the mandrel, and there is an advantage that there is no large resistance when the tubular film is taken out.

[0026]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view showing one embodiment of the method for producing a tubular film of the present invention. In FIG. 1, reference numeral 1 denotes an extruder, 2 denotes an annular die provided in front of the extruder 1, and a molten thermoplastic resin in a cylinder 12 is extruded by rotation of a screw shaft 11 of the extruder 1, and a breaker Introduced into the annular die 2 via the plate 13 and the adapter 14,
11 and an annular passage 212 to form a tube. Reference numeral 15 denotes a hopper, and 16 denotes a motor for driving the screw shaft 11.

3 is an external water cooling device provided below the annular die 2, 4 is a mandrel provided inside the external water cooling device 3, and 5 is a folding device provided below the external water cooling device 3 and the mandrel 4. , 6 are pinch rolls provided below the folding device 5.

Tube 7 extruded from annular die 2
Is cooled by the external water cooling device 3 and the mandrel 4,
It is folded by the folding device 5, completely folded by the pinch roll 6, and transferred to the next step as shown by an arrow a.

As shown in FIG. 2, the external cooling device 3
A first water tank 31 at the center and a second water tank 32 outside the first water tank 31 are provided. The boundary wall 311 between the first water tank 31 and the second water tank 32 is lower than the outer wall 321 of the second water tank 32.

Reference numeral 312 denotes a water injection pipe. One end of the water injection pipe 312 is attached to the boundary wall 311. The cooling water injected from the water injection pipe 34 into the second water tank 32 hits the baffle plate 313 as shown by the arrow b. , The momentum of the water flow is weakened and directed upward, and is stored in the first water tank 31.

Water overflowing from the first water tank 31 accumulates in the second water tank 32 and is drained from the second water tank 32 from a drain pipe 322 as shown by an arrow c. Reference numeral 314 denotes a rubber annular plate provided at the bottom of the first water tank 31. The outer peripheral edge of the annular plate 314
15 is attached to the bottom of the first water tank 31 so that the inner peripheral edge of the annular plate 314 is pressed against the surface of the tube 7.

As shown in FIG. 2, the mandrel 4 comprises a cylindrical main body 41 and a concentric multiple pipe 42. A spiral groove 411 is provided on the outer peripheral surface of the cylindrical main body 41,
One end of the water supply channel 4111 is opened at the bottom of the uppermost spiral groove 411. One end of a drain channel 4112 is opened at the bottom of the lowermost spiral groove 411, and the other end of the drain channel 4112 is opened to a water tank 412 in the cylindrical main body 41.

A water discharge groove 413 is provided above the spiral groove 411 of the cylindrical main body 41, a porous annular body 4131 is fitted into the water discharge groove 413, and the water supply channel 41 is inserted into the water discharge groove 413.
One end of 32 is communicated.

A groove 415 is provided on the outer peripheral surface below the spiral groove 411 of the cylindrical main body 41, and a porous annular body 4151 is fitted into the groove 415.

A drain 4152 is provided from the bottom of the groove 415, and the lower end of the drain 4152 is opened to a water tank 416 in the cylindrical main body 41.

The multi-tube 42 has five concentric tubes 421, 42.
2, 423, 424, and 425. The upper end of the innermost pipe 421 passes through the core die 21 of the annular die 2, and the intake air of the upper plate 22 of the supply / intake water part 20 provided above the core die 21. The mouth 23 is in communication. The lower end of the central tube 421 penetrates the cylindrical main body 41 and is opened in the tubular film 7.

A water pump 4221 is formed between the central pipe 421 and the pipe 422 outside thereof. The upper end of the water pump 4221 is communicated with the suction port 24 provided in the supply / intake water section 20. Is a water tank 4 in the cylindrical main body 41.
16, the water in the water tank 416 is stored in a water tank (not shown) from the suction port 24 via the water pumping channel 4221.

A pumping channel 4231 is formed between the pipe 422 and the pipe 423 on the outside thereof. The upper end of the pumping channel 4231 communicates with the suction port 25 provided in the supply / intake water section 20, and the lower end of the pumping channel 4231. Is a water tank 4 provided in the cylindrical main body 41.
The water inside 12 is stored in a water tank (not shown) from the suction port 25 via a water pumping channel 4231.

A water supply channel 4241 is formed between the pipe 423 and a pipe 424 outside the pipe 423. The upper end of the water supply channel 4241 is communicated with the water supply port 26 provided in the supply / intake water section 20, and the lower end of the water supply channel 4241 is provided. Is connected to the other end of the water supply channel 4111.

A water supply channel 4251 is formed between the pipe 424 and the outer pipe 425, and the upper end of the water supply channel 4251 communicates with the water supply port 27 provided in the supply / intake water section 20, and the lower end of the water supply channel 4251. Is connected to the water outlet 413.

An air supply passage 4261 is provided outside the pipe 425, and the upper end of the air supply passage 4261 is communicated with an air supply port 28 provided in an air supply portion 213 above the core die 21.
The lower end of 61 is communicated with a fume port 213.

Next, a method of forming a tubular film using the apparatus shown in FIGS. 1 and 2 will be described. As shown in FIG. 1, a molten thermoplastic resin extruded from an extruder 1 is introduced into an annular die 2 via an adapter 14, and is formed into a tube as shown in FIG. The guide film 7 is guided between the external water cooling device 3 and the mandrel 4.

By blowing air from the air supply port 28 provided in the air supply section 213, the air is blown out from the blow port 213 through an air supply path 4261 provided in the core mold 21. In addition, air is sucked from the lower end of the pipe 421 by being sucked from the suction port 23 provided in the supply / intake water section 20. Further, by supplying water to the water supply ports 26 and 27, water is discharged from the spiral groove 411 of the mandrel 4 and the water supply path 4
Water is discharged from the porous annular body 4131 fitted in the water discharge groove 413 at the tip of the 132.

The outer surface of the tubular film 7 guided between the external water cooling device 3 and the mandrel 4 is
Is rapidly cooled by direct water cooling by the cooling water in the first water tank 31. In addition, tubular film 7
The inner surface is directly water-cooled by the cooling water discharged from the porous annular body 4131, and further rapidly cooled by water cooling by the water supply from the spiral groove 411.

Next, since the tube 7 moves downward and comes into contact with the porous annular member 4151, the cooling water adhered to the inner surface of the tube 7 is absorbed, so that even if the tube 7 is stretched in a later step, stretching unevenness occurs. There is no fear. The sucked cooling water is stored in the water tank 416, and the stored cooling water is stored in the water pump 4
The water is drained from the suction port 24 via 221.

Pipes 421 and 4 for supplying and discharging water and supplying and exhausting air
22, 423, 424, and 425 are provided concentrically, so that the flow of air and cooling water is always symmetrical with respect to the central axis of the die 2 and the mandrel 4, and the flow between the mandrel 4 and the tubular film 7. , The amount of cooling water and the amount of air on the circumference become uniform, and a tubular film having a uniform thickness on the circumference can be manufactured.

Since the supply of the cooling water to the tubular film 7 is performed by contact with the porous annular member 4131, the cooling water having a low ejection speed can be provided by increasing the area of the outer surface of the porous annular member 4131. The tubular film 7 can be cooled.
Can be cooled uniformly.

FIG. 3 is a sectional view showing a main part of another embodiment of the method for producing a tubular film of the present invention. In the embodiment of the method for manufacturing a tubular film shown in FIG. 3, a groove 417 is provided below the groove 415.
A wiping sponge ring 4171 is fitted in the groove, and the cooling water remaining on the inner surface of the tubular film 7 is wiped by the wiping sponge ring 4171. Road 422
1 to be pumped.

FIG. 4 is an enlarged view of a portion indicated by a circle A in FIG.
As shown in the figure, the depth of the groove 417 is enlarged, the thickness of the inner peripheral portion of the wiping sponge ring 4171 fitted in the groove 417 is larger than the thickness of the outer peripheral portion, and the wiping sponge ring 4171 is 417 is not easily separated.

The wiping sponge ring 4171 protrudes from the outer peripheral surface of the mandrel 4 by α, and when the tubular film 7 passes over the wiping sponge ring 4171, the wiping sponge ring 4171 contracts due to elastic deformation, and its expansion and recovery is restored. The tubular film 7 is pressed against the inner surface by force and can be wiped off. The material of the wiping sponge ring 4171 can be polyurethane, polystyrene, polyethylene, polypropylene, or the like. Sponge ring 4 for wiping
The micropores of 171 need to be continuous.

FIG. 5 is an enlarged development view showing an example of using a long strip 4171a of a flexible wiping body made of open-cell polyurethane foam instead of using the wiping sponge ring 4171. FIG. FIG. 6 is a sectional view taken along line VI-VI of FIG. That is, in the example shown in FIG.
A large number of protrusions 4173, 41
73 are projected in a staggered manner, and a large number of projections 4173, 4
173. As shown in FIGS. 5 and 6, a flexible wiping strip 4171 made of open-cell polyurethane foam is provided.
a is zigzag. Long wiping strip 4
The cooling water wiped by 171a is drained from the groove 417 via the drain passage 4172.

FIG. 7 is a developed view showing another example of the wiping member. The wiping member 4171b shown in FIG. 7 is of a fixed length, and as shown in FIGS.
171b are obliquely arranged and fitted on the outer peripheral surface of the cylindrical main body 41, and the inner surface of the tubular film is
The cooling water adhering to the inner surface of the tubular film is completely wiped off by being repeatedly contacted with 1b.

FIG. 9 is a developed view showing still another example of the wiping member. The wiping member 4171c shown in FIG. 9 has a short portion on the surface thereof, and the embedded portion has a continuous annular body 4171 as shown in FIGS.
d, and the exposed portion is a large number of short wiping members 41.
71 c are staggered and fitted on the outer peripheral surface of the cylindrical main body 41, and the inner surface of the tubular film 7 is
The cooling water adhering to the inner surface of the tubular film 7 is completely wiped by being repeatedly contacted with 71c.

Further, the wiping member 4171c holds the wiping member 41 when the tubular film 7 is pulled in the pulling direction.
The wiping member 4171c receives a ring-shaped body 417 although the rubbing member 4171c is strongly pulled in the pulling direction by the frictional force of the surface of the member 71c.
Since 1d is provided, the relative position between the wiping member 4171c and the cylindrical main body 41 is stable, and there is no possibility that the wiping member 4171c is detached from the cylindrical main body 41 due to the frictional force of the take-off.

FIG. 11 is a sectional view showing still another embodiment of the method for producing a tubular film of the present invention. The external water cooling device 3 shown in FIG. 11 includes a first water tank 31 at the center, a second water tank 32 outside the first water tank 31, and a third water tank 33 outside the first water tank. The boundary wall 311 between the first water tank 31 and the second water tank 32 is higher than the boundary wall 321 between the second water tank 32 and the third water tank 33, and the second water tank 3
The boundary wall 321 between the second and third water tanks 33 is the third water tank 33
Is higher than the outer wall 331.

Reference numeral 34 denotes a water supply pipe. One end of the water supply pipe 34 is attached to a boundary wall 321 between the second water tank 32 and the third water tank 33, and is supplied from the water supply pipe 34 into the second water tank 32. The cooling water hits the baffle plate 322 as shown by the arrow b,
The momentum is weakened and directed upward, hits the shelf 323, faces downward as indicated by the arrow c, and is introduced into the first water tank 31 through the through hole 312 and stored as indicated by the arrow d.

Water overflowing from the first water tank 31 accumulates in the second water tank 32, water overflowing from the second water tank 32 accumulates in the third water tank 33, and water flowing from the third water tank 33 through a drain pipe 332. It is designed to be drained. Boundary wall 311 between first water tank 31 and second water tank 32
The shape viewed from the side of the upper end of the is a saw-tooth-shaped uneven shape,
The water level in the first water tank 31 is designed to be constant. Reference numeral 313 denotes a rubber annular plate provided at the bottom of the first water tank 31, and an outer peripheral edge of the annular plate 313 is a mounting bracket 314.
Is attached to the bottom of the first water tank 31 by the
The outer peripheral edge of 3 is pressed against the tubular film 7.

As shown in FIG. 11, the mandrel 4 includes a cylindrical main body 41 and a concentric multiple pipe 42.
A spiral groove 411 is provided on the outer peripheral surface of the cylindrical main body 41, and a water supply channel 4111 is provided at the bottom of the uppermost spiral groove 411.
Is open at one end. One end of a drainage channel 4112 is opened at the bottom of the lowermost spiral groove 411, and the drainage channel 411 is opened.
The other end of 2 is opened to a water tank 412 in the cylindrical main body 41.

A water discharge groove 413 is provided above the spiral groove 411 of the cylindrical main body 41 as shown in FIG. An annular groove-shaped water tank 414 is provided above the water discharge groove 413 of the cylindrical main body 41, and the shape of the outer wall 4141 of the water tank 414 viewed from the side at the upper end is a saw-toothed uneven shape. The water level is designed to be constant. A drain 4142 is provided from the bottom of the water tank 414.
The lower end of 142 is open to a water tank 412 in the cylindrical main body 41.

A groove 415 is provided below the spiral groove 411 of the cylindrical main body 41, and the groove 415 is provided in the porous annular body 41.
The drainage channel 4152 is provided from the bottom of the groove 415, and the lower end of the drainage channel 4152 is opened to the water tank 412 in the cylindrical main body 41.

The multi-tube 42 has six concentric tubes 421, 42.
2, 423, 424, 425, 426. The upper end of the innermost tube 421 passes through the core 21 of the annular die 2 and communicates with the supply port 23 of the upper plate 22 attached to the upper end of the core 21. Have been. The lower end of the central tube 421 penetrates the cylindrical main body 41 and is opened in the tubular film 7.

A pump channel 4221 is formed between the center tube 421 and the outer tube 422, and the upper end of the pump channel 4221 communicates with the suction port 24 provided in the core mold 21, and the lower end of the pump channel 4221. Is opened in a water tank 412 in the cylindrical main body 41, and water in the water tank 412 is stored in a water tank (not shown) from the suction port 24 via a water pumping channel 4221.

An air supply path 4231a is formed between the pipe 422 and the pipe 423 outside the pipe 422. The upper end of the air supply path 4231a is communicated with the air supply port 25a provided in the core mold 21, and the air supply path 4231a is formed. Is connected to the upper end of an air supply passage 4232 provided in the cylindrical main body 41, and the lower end of the air supply passage 4232 is opened in the tubular film 7.

A water supply channel 4241 is formed between the pipe 423 and the outer pipe 424, and the upper end of the water supply channel 4241 is communicated with the water supply port 26 provided in the core mold 21.
The lower end of 41 is connected to the other end of the water supply channel 4111.

A water supply channel 4251 is formed between the pipe 424 and the outer pipe 425, and the upper end of the water supply channel 4251 communicates with the water supply port 27 provided in the core mold 21,
The lower end of 51 is connected to the water supply channel 4143 and the water discharge groove 413.

An air supply path 4261 is formed between the pipe 425 and the outermost pipe 426, and the upper end of the air supply path 4261 is communicated with the air supply port 28 provided in the core mold 21.
The lower end of 61 is communicated with a blowing port 418 provided near the upper end of the cylindrical main body 41.

Next, in the embodiment shown in FIG. 11, air and lubricant are blown out from the lower end of the pipe 421 by blowing air and lubricant from the supply port 23 of the upper plate 22 attached to the upper end of the core mold 21. Is done. In addition, air is blown from air supply ports 25a and 28 provided in the core mold 21 to supply air 4132 and fumed ports 4 provided in the cylindrical main body 41.
Air is ejected from 18. Further, by supplying water to the water supply ports 26 and 27, water is supplied from the spiral groove 411 of the mandrel 4 and water is discharged from the water discharge groove 413, and the water tank 414 is provided.
Water is supplied to

The outer surface of the tubular film 7 guided between the external water cooling device 3 and the mandrel 4 is
Is rapidly cooled by direct water cooling by the cooling water in the first water tank 31. In addition, tubular film 7
The inner surface is directly cooled by the cooling water overflowing from the water tank 414, then directly cooled by the cooling water discharged from the water discharging groove 413, and further rapidly cooled by being cooled by the water supply from the spiral groove 411.

Next, the tubular film 7 moves downward, and the inner surface of the tubular film 7 comes into contact with the porous annular body 4151 fitted in the groove 415, and then comes into contact with the porous annular body 4151. Film 7
Since the cooling water attached to the inner surface of the substrate is absorbed, there is no danger of drawing unevenness even if the substrate is drawn in a subsequent step. The sucked cooling water is stored in the water tank 412 via the drainage channel 4152, and the cooling water stored in the water tank 412 is drained from the suction port 24 via the water pumping channel 4221.

FIG. 13 is an explanatory view showing still another embodiment of the method for producing a tubular film according to the present invention. In the embodiment shown in FIG. 13, an annular die 2a different from the annular die 2 in the embodiment shown in FIGS.
Is different from the embodiment shown in FIGS. 1 and 2 in other respects, and is almost the same as the embodiment shown in FIGS. 1 and 2 in other points.

As shown in FIG. 13, the annular die 2a includes a rotating shaft 200, a stepped cylindrical portion 210, a rotating die 220, a rotating die 230, a rotating die 240, and a rotating die 250.

A hollow 201 is formed in the center of the rotating shaft 200, and a multiple tube 42 is fitted concentrically in the hollow 201. The rotation shaft 200 has a sprocket wheel 202
Is attached, and the power is transmitted to the sprocket wheel 202 so that the rotating shaft 200 is rotated.

The stepped cylindrical portion 210 is fitted to the outside of the rotating shaft 200, and the stepped cylindrical portion 210 has contact peripheral surfaces 2111, 211
112, 2113, 2114 and contact end faces 2121, 2
122, 2123, and 2124, and the stepped cylindrical portion 2
The inner diameter of the cylindrical portion below 10 is increased.

The contact end surfaces of the stepped cylindrical portion 210 of the rotary shaft 200 with the contact end surfaces 2121, 2122, 2123, 2124 are provided with leakage resin discharge holes 2011, 2012, 2013,
2014 is provided.

The rotary shaft 200 and the stepped cylindrical portion 210 are screwed into the nut 207 via the thrust bearing 206 to make contact end surfaces 2121 and 212 of the stepped cylindrical portion 210.
2, 2123 and 2124 are closely connected.

The resin supply passage 213 is provided in the stepped cylindrical portion 210.
1, 2132 and 2133 are provided. The resin supply passage 2131 is formed on the contact peripheral surface 2112 with the resin supply passage 213.
2 are opened in the contact peripheral surface 2113, and the resin supply passage 2133 is opened in the contact peripheral surface 2114, and annular passages 2041, 2042, and 204 are formed on the rotation shaft 200 side of these openings.
3 are provided, and these annular passages 2041, 2042,
Reference numeral 2043 is formed as a communicating portion of a resin supply passage between the stepped cylindrical portion 210 and the rotating shaft 200.

In the rotary shaft 200, the annular passages 2041, 2
Resin supply passages 2051, 2
052 and 2053 are provided in the axial direction. As shown in FIG. 14, four resin supply passages 2051, 2052, and 2053 are provided at four equally-spaced locations on the circumference.

The rotary die 220, the rotary die 230, the rotary die 240, and the rotary die 250 are integrated. Inside the rotating die 220, the cavity 20 at the center of the rotating shaft 200 is provided.
1 are provided with a cavity 221. .

The rotary die 220 is provided with an axial passage 2201 communicating with the annular passage 2051 of the rotary shaft 200. Similarly, the rotary die 220 has an axial passage 2202 communicating with the annular passage 2052 of the rotating shaft 200 and an axial passage 2 communicating with the annular passage 2053 of the rotating shaft 200.
203 is provided.

[0098] The cylinder is further connected to the passage
A divided four-way threaded channel-shaped channel 2223 is provided. The passage 2223 gradually decreases in depth, and at the same time, the gap between the passage 2223 and the outer wall surrounding the passage 2223 expands, and finally the annular passage 223 is formed.

As shown in FIG. 13, a semi-circular groove 231 communicating with the two passages 2201 of the rotating die 220 is provided on the lower end surface of the rotating die 230, and the passages 2311 are formed axially from both ends. Is provided. This passage 2311
Are arranged at equal intervals in the circumferential direction.

Similarly, a semicircular groove 232 communicating with the two passages 2202 of the rotating die 220 is provided on the lower end surface of the rotating die 230, and passages 2321 are provided from both ends in the axial direction. I have. The passages 2321 are also provided at four locations at equal intervals in the circumferential direction.

Further, the outer periphery of the lower end of the rotary die 230 is communicated with the passage 2321 so as to communicate with the four-threaded passage 233.
Is provided. Similarly, the screw-shaped passage 233 reaches the annular passage 234.

Similarly, the rotary die 240 is provided with a passage 241 communicating with the passage 2311 of the rotary die 230, and the outer peripheral portion of the lower cylindrical portion of the rotary die 240 is provided with four passages communicating with the passage 241. A screw-shaped passage 242 is provided, and the passage 242 similarly reaches the annular passage 243.

These annular passages 223, 234, 243
Are joined at the junction 251 and reach the discharge port 253 via the merged annular flow path 252.

The passages 2051, 2052 of the rotating shaft 200,
2053, passages 2201, 2202 of the rotary die 220,
2203, passages 2311 and 2321 of the rotary die 230,
The passage 241 of the rotary die 230 is sequentially branched to a position symmetric with respect to the center axis of the rotary shaft 200.

A core type head 260 is provided at the upper end of the multiple pipe 42 fitted in the cavity 201 of the rotating shaft 200. The multi-tube 42 includes five concentric tubes 421, 422, and 42.
3, 424, 425, the innermost tube 421
The upper end of the core-type head 260 is
0 is connected to a supply port 262 of an upper plate 261 attached to the upper end of the “0”. The lower end of the central tube 421 is the cylindrical body 41
And is opened in the tubular film 7 similarly to the embodiment shown in FIGS.

A pump 4221 is formed between the central pipe 421 and the pipe 422 outside the pipe. The upper end of the pump 4221 communicates with a suction port 263 provided in the core type head 260. The lower end is opened in a water tank (not shown) in the cylindrical main body 41, and water in the water tank is stored in another water tank (not shown) from the suction port 263 via the water pumping channel 4221.

An air supply path 4231 is formed between the pipe 422 and the outer pipe 423, and the upper end of the air supply path 4231 is communicated with an air supply port 264 provided in the core type head 260.
The lower end of the air supply passage 4231 communicates with the upper end of an air supply passage (not shown) provided in the cylindrical main body 41, and the lower end of the air supply passage is opened in the tubular film 7.

A water supply channel 4241 is formed between the pipe 423 and the outer pipe 424, and the upper end of the water supply channel 4241 is communicated with a water supply port 265 provided in the core type head 260.
The lower end of the water supply channel 4241 is connected to the other end of the water supply channel 4111, the water discharge groove 413, and the water supply channel 4143.

A water supply channel 4251 is formed between the pipe 424 and the outermost pipe 425, and the upper end of the water supply channel 4251 is communicated with an air supply port 266 provided in the core type head 260.
The lower end of the air supply passage 4251 is communicated with an air outlet 418 provided near the upper end of the cylindrical main body 41.

Next, a method for forming a tubular film using the apparatus shown in FIG. 13 will be described. As shown in FIG. 13, the thermoplastic resin in the molten state extruded from the extruder passes through an adapter and is supplied to the resin supply passages 2131, 2132, and 2133 of the stepped cylindrical portion 210 of the annular die 2a.
Will be introduced.

Since the rotating shaft 200 is rotated with respect to the passage 2131, the resin supplied from the passage 2131 is equally distributed to the four passages 2051 via the passage 2041, and the resin is supplied to each of the screw passages 242. Evenly distributed. Similarly, the resin from the passages 2132 and 2133 is evenly distributed to the threaded passages 2321 and 2223.

As a result, the resin is uniformly discharged from the annular discharge port 253, and the tubular film 7 is formed. Next, the outer surface of the tubular film 7 guided between the external water cooling device 3 and the mandrel 4 is the same as that shown in FIGS.
Is rapidly cooled by direct water cooling by the cooling water in the first water tank 31. Next, when the inner surface of the tubular film 7 is brought into contact with the porous annular body 413, the tubular film 7 is directly cooled with the cooling water and rapidly cooled.

Although the embodiments of the present invention have been described with reference to the drawings, the specific embodiments of the present invention are not limited to the illustrated embodiments, and modifications that do not depart from the gist of the present invention may be made. include.

[0096]

According to the method for manufacturing a tubular film of the present invention, the flow path of the cooling water and the air becomes uniform, the flow rates of the cooling water and the air become uniform, and the cooling rate of the tubular film is reduced. Uniformity and thus uniformity of the thickness of the tubular film can be ensured.

In the tubular film manufacturing apparatus according to the second aspect of the present invention, the flow path of the cooling water and the air becomes uniform, the flow rates of the cooling water and the air become uniform, and the cooling rate of the tubular film is reduced. Uniformity and thus uniformity of the thickness of the tubular film can be ensured.

In the method for producing a tubular film according to the present invention, a large number of water streams are supplied from a large number of pores on a wide surface of the porous annular body. It is jetted uniformly from the surface, and the tubular film can be cooled uniformly.

Further, in the tubular film manufacturing apparatus according to the present invention, a large number of water flows from the large number of holes on the wide surface of the porous annular body, but a large amount of water flows through the large area of the porous annular body. It is jetted uniformly from the surface, and the tubular film can be cooled uniformly.

In the method for producing a tubular film according to the present invention, water is supplied over a large area in contact with the tubular film of the porous annular body, and the tubular film is strongly sucked into the mandrel. This is advantageous in that the resistance is not increased when the tubular film is taken up.

In the apparatus for manufacturing a tubular film according to the present invention, water is supplied over a large area in contact with the tubular film of the porous annular body, and the tubular film is strongly sucked into the mandrel. This is advantageous in that the resistance is not increased when the tubular film is taken up.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a method for producing a tubular film of the present invention.

FIG. 2 is an enlarged sectional view showing a main part of the embodiment shown in FIG. 1;

FIG. 3 is a sectional view showing another embodiment of the method for producing a tubular film of the present invention.

FIG. 4 is an enlarged sectional view showing a circle A in FIG. 3 in an enlarged manner.

FIG. 5 is a development view showing another example of the wiping member.

FIG. 6 is a sectional view taken along line VI-VI in FIG. 5;

FIG. 7 is a developed view showing still another example of the wiping material.

FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 7;

FIG. 9 is a developed view showing still another example of the wiping member.

FIG. 10 is a sectional view taken along line XX in FIG. 9;

FIG. 11 is a sectional view showing still another embodiment of the method for producing a tubular film of the present invention.

FIG. 12 is a sectional view taken along line XII-XII in FIG. 11;

FIG. 13 is an enlarged sectional view showing a main part of another embodiment of the method for producing a tubular film of the present invention.

FIG. 14 is a sectional view taken along the line IVX-IVX in FIG. 13;

FIG. 15 is a sectional view taken along line VX-VX in FIG. 13;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Extruder 2, 2a Annular die 3 External water cooling device 4 Mandrel 41 Cylindrical main body 4131, 4151 Porous annular body 42 Multi-tube 5 Folding device 6 Pinch roll 7 Tubular film

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F207 AA04E AA11 AA12 AA15 AA29 AB16 AG08 AJ10 AK02 KA01 KA17 KK55 KK63 KK76 KL83 KL88 KL89 KL99

Claims (6)

[Claims] 1. A method of manufacturing a tubular film in which a thermoplastic resin is melt-plasticized, extruded into a tubular film downward from an annular die, guided to a mandrel, and solidified by cooling with water from inside and outside of the tubular film. A pipe for supplying water to the mandrel, a pipe for sucking used cooling water and discharging it out of the device, and a film for cooling the inner surface of the tubular film by directly contacting the cooling water with the required cooling water. A method for producing a tubular film, wherein a tube for supplying air for inflating to a diameter and a tube for discharging air are concentrically arranged in a mandrel. 2. A tubular film manufacturing apparatus in which a thermoplastic resin is melt-plasticized, extruded into a tubular film downward from an annular die, guided to a mandrel, and solidified by cooling with water from inside and outside of the tubular film. A pipe for supplying water to the mandrel and a pipe for sucking used water and discharging it out of the device, and a film having a required diameter to cool the inner surface of the tubular film by directly contacting the cooling water. An apparatus for manufacturing a tubular film, wherein a pipe for supplying air for inflating the pipe and a pipe for discharging the air are arranged concentrically within a mandrel. 3. A porous annular body is provided on an upper surface of a mandrel for directly supplying cooling water to the inner surface of the tubular film, and cooling water supplied from a water supply pipe is supplied through the porous annular body. The method for producing a tubular film according to claim 1, wherein the film is supplied to an inner surface of the film. 4. A porous annular body is provided on the surface of a mandrel for directly supplying cooling water to the inner surface of the tubular film, and cooling water supplied from a water supply pipe is supplied to the tubular film through the porous annular body. 3. The apparatus for producing a tubular film according to claim 2, wherein the apparatus is supplied to an inner surface. 5. A porous annular body is provided on the lower surface of the mandrel for sucking cooling water attached to the inner surface of the tubular film, and the cooling water attached to the tubular film surface is sucked through the porous annular body. The method for producing a tubular film according to claim 1, wherein the water is drained through a pipe provided inside the mandrel. 6. A porous annular body is provided on the lower surface of the mandrel for sucking cooling water attached to the inner surface of the tubular film, and the cooling water attached to the tubular film surface is sucked through the porous annular body. The apparatus for producing a tubular film according to claim 1, wherein the water is drained through a pipe provided inside the mandrel.