JPWO2005097469A1 - Blown film production equipment - Google Patents

Abstract

Cooling air is blown from the air ring provided at a position surrounding the circular slit above the molding die to the outer periphery of the tubular molten synthetic resin extruded from the circular slit of the molding die. A blown film production apparatus for producing a tubular film by cooling the molten synthetic resin. A spiral cooling air flow path is formed between the cooling air inlet of the air ring and the annular cooling air outlet, and a uniform air volume in the circumferential direction from the annular cooling air outlet to the outer periphery of the tubular molten synthetic resin, Blow cooling air at wind speed. A plurality of heating means whose temperature can be individually adjusted at the annular cooling air outlet of the air ring are arranged at predetermined intervals in the circumferential direction between adjacent heating means and sprayed on the outer periphery of the tube-shaped molten synthetic resin The temperature of the cooling air generated is controlled in the circumferential direction. In order to adjust the air volume, wind speed, and temperature of the cooling air blown from the annular cooling air outlet to the outer periphery of the tubular molten synthetic resin in the circumferential direction, a thickness meter that measures the thickness of the manufactured tubular film is low-cost. At the same time, improve measurement accuracy.

Description

  The present invention relates to an inflation film manufacturing apparatus, and more particularly to an inflation film manufacturing apparatus that can effectively prevent unevenness in the thickness of a tubular film manufactured by an inflation film manufacturing apparatus.

  The inflation film manufacturing apparatus is provided with cooling air from an air ring provided at a position surrounding the circular slit above the molding die on the outer periphery of the tube-shaped molten synthetic resin extruded from the circular slit of the molding die. Is sprayed to cool the tubular molten synthetic resin to produce a tubular film.

  The tubular film thus produced is usually crushed flat by a stabilizer, pulled by a pinch roll, measured for thickness by a thickness meter, and then wound on a take-up roll.

  When blowing cooling air from the air ring to the outer periphery of the tube-shaped molten synthetic resin, the internal air is blown out from the center of the molding die with a predetermined pressure, thereby expanding the tube-shaped molten synthetic resin, and air is applied to the outer periphery. Cooling air may be blown from the ring.

  That is, when the tube-shaped molten synthetic resin is in a molten state, it is expanded by internal air blown from the center of the molding die at a predetermined pressure, and is stretched by a pinch roll to be thin-walled. It becomes a tube-shaped film.

  However, after the tube film is cooled by receiving cooling air from the air ring and solidified, it does not become thinner.

  Therefore, when the amount of the melted synthetic resin extruded from the circular slit of the molding die is not uniform over the entire circumference of the circular slit, or when the cooling of the tubular film by the cooling air is not uniform in the circumferential direction, When the temperature is not uniform in the circumferential direction, the thickness of the manufactured tubular film becomes nonuniform in the circumferential direction.

  In order to prevent the thickness of the tube-shaped film manufactured in this way from becoming non-uniform and causing uneven thickness, the inflation film manufacturing apparatus usually measures the thickness of the manufactured tube-shaped film. A thickness gauge is provided.

  It is attempted to control the amount of molten synthetic resin extruded from the circular slit of the molding die and the cooling state by the cooling air (cooling air flow rate, temperature, etc.) according to the measurement result of this thickness gauge. ing.

  This prevents the tube-shaped film manufactured by the inflation film manufacturing apparatus from having a thickness variation (uneven thickness) in the circumferential direction.

  An example of such a trial which has been conventionally performed will be described with reference to FIGS.

  Cooling air is blown to the outer periphery of the tube-shaped molten synthetic resin 205 extruded from the circular slit 202a of the molding die 202 from an air ring 210 disposed at a position surrounding the circular slit 202a above the molding die 202. Then, the tube-shaped molten synthetic resin 205 is cooled to manufacture the tube-shaped film 206.

  The air ring 210 surrounds the cooling air intake 212 on the outer peripheral side, surrounds the tubular molten synthetic resin 205 on the center side, and is introduced from the cooling air intake 212 toward the outer periphery of the tubular molten synthetic resin 205. An annular cooling air outlet 213 for blowing air is provided, and a cooling air passage 215 is provided between the cooling air inlet 212 and the cooling air outlet 213.

  As shown in FIGS. 18 and 19, for example, two cooling air inlets 212 are provided, and two baffle plates 254 are provided concentrically in the cooling air flow path 215.

  Cooling air from a blower (not shown) flows into the cooling air intake port 212 and hits the annular baffle plate 254 to be dispersed in the circumferential direction as shown in FIG. And after that, it becomes a flow which goes to the tube-shaped molten synthetic resin 205, and blows off from the annular cooling wind blower outlet 213.

  However, the annular baffle plate 254 cannot sufficiently rectify the cooling air, and the flow velocity of the cooling air blown out from the annular cooling air outlet 213 varies in the circumferential direction as shown in FIG. . In FIG. 20, the positions indicated by reference numerals 212 and 212 are the positions of the cooling air intakes.

  Since the uneven thickness (thickness variation) of the synthetic resin film 206 depends on the state of the cooling air, as shown in FIG. 20, a tube-shaped synthetic resin cooled by the cooling air having a variation in the flow velocity in the circumferential direction. The uneven thickness of the film 206 becomes large.

  The conventional inflation film manufacturing apparatus schematically shown in FIG. 21 is proposed in Japanese Patent Publication No. 63-11131.

  This is because the temperature of the molding die 202 is partially adjusted in the circumferential direction so that the temperature of the extruded tubular synthetic resin 205 is partially adjusted in the circumferential direction. This is intended to control the uneven thickness of 206.

  On the outer periphery of the circular die slit 202a of the molding die 202, a plurality of heaters 243 capable of individually adjusting the temperature are provided. Thereby, the temperature of the tube-shaped molten synthetic resin 205 extruded from the die slit 202a is partially adjusted in the circumferential direction.

  However, in the blown film manufacturing apparatus proposed in Japanese Patent Publication No. 63-11131, the forming die 202 is made of metal. For this reason, even if the temperature of the heater 243 is individually adjusted even if the temperature of the heater 243 is adjusted, the heat is transferred to an adjacent portion that does not require adjustment, and the temperature of the molding die 202 is finely adjusted in the circumferential direction as desired. It was difficult. That is, it is difficult to finely adjust the temperature of the target portion in the circumferential direction of the tube-shaped molten synthetic resin 205 extruded from the die slit 202a.

  Therefore, the thickness of the tubular synthetic resin film 206 could not be controlled with high accuracy.

  In addition, since the heater 243 indirectly heats the tube-shaped molten synthetic resin 205 through the metal die 202, there is a problem that the thermal efficiency is also poor.

  A conventional inflation film manufacturing apparatus schematically shown in FIG. 22 is proposed in Japanese Patent Application Laid-Open No. 2004-330537.

  This partially controls the temperature of the cooling air in the circumferential direction of the air ring.

  A ring-shaped baffle plate 252 is disposed in the cooling air flow path 215 so as to be orthogonal to the flow of the cooling air. A large number of heating elements 251 are embedded in the ring-shaped baffle plate 252 at predetermined intervals in the circumferential direction.

  In the inflation film manufacturing apparatus proposed in Japanese Patent Application Laid-Open No. 2004-330537, the heat transfer area where the baffle plate 252 is in contact with the cooling air is small, and the heating element 251 embedded in the baffle plate 252 changes to the cooling air. Therefore, it was difficult to efficiently control the temperature of the cooling air blown around the outer periphery of the tubular molten synthetic resin 205 in the circumferential direction.

  FIG. 23 illustrates an outline of a thickness meter provided in a conventional inflation film manufacturing apparatus. Conventionally, as a judgment material for controlling the cooling state (cooling air volume, temperature, etc.) by cooling air in order to prevent uneven thickness in the manufactured tubular film, The thickness was measured using such a thickness meter.

  The thickness gauge shown in FIG. 23 measures the thicknesses of the flat films 6a and 6b obtained by cutting and opening the manufactured tubular film into two sheets. There is provided conveying means for conveying the flat films 6a and 6b cut into two pieces to face each other in the longitudinal direction (direction orthogonal to the drawing). In addition, two detectors (reflection type) arranged so as to be movable in the lateral direction (direction of arrow 69) between the two flat films 6a and 6b conveyed in the longitudinal direction so as to face each other in this way. Infrared thickness gauge) 58a, 58b. The detectors 58a and 58b have a detection surface 57 on one side, and the detection surface 57 faces the films 6a and 6b, respectively. As shown in the figure, reflectors 67a and 67b are disposed behind the films 6a and 6b. The detectors 58a and 58b are moved in the direction of the arrow 69, respectively, and the thicknesses of the films 6a and 6b conveyed in the direction orthogonal to the drawing are measured.

  However, the reflection-type infrared thickness gauge having such a configuration is the most expensive among thickness gauges. Therefore, even if it is possible to control the cooling state (cooling air volume, temperature, etc.) by the cooling air according to the uneven distribution of the thickness measured by this, the price of the entire inflation film manufacturing apparatus will increase. There was a problem.

  FIG. 24 illustrates the outline of another thickness gauge provided in a conventional inflation film manufacturing apparatus. This thickness gauge is proposed in Japanese Patent Application Laid-Open No. 11-248424 in Japan.

  The thickness gauge shown in FIG. 24 is also for measuring the thickness of a single flat film 6a obtained by cutting and opening the manufactured tubular film. Each flat film (for example, the film 6a) cut into two pieces is cut and contacted on the surface of the reference roll 70. At this time, it is a non-contact measurement sensor (laser beam type thickness meter) that measures the thickness by irradiating the laser beam 71 from the tangential direction of the contact surface of the reference roll 70 on which the film 6a is traveling. The laser beam 71 emitted from the projector 72a is captured by the light receiver 72b, and the thickness of the film 6a is measured by the amount of the laser beam 71 shielded by the film 6a traveling on the surface of the reference roll 70.

  In the case of such a thickness gauge, when air is interposed between the surface of the reference roll 70 and the film 6a and the film 6a does not adhere to the surface of the reference roll 70, and the height of the upper surface of the film 6a changes. The laser beam 71 captures its height, and the thickness of the film 6a becomes inaccurate.

  Therefore, in the thickness meter provided in the conventional inflation film manufacturing apparatus as shown in FIG. 24, the film 6a needs to be in close contact with the reference roll 70.

  For this reason, the fluid ejecting nozzle 80 is provided, and the film 6 a is pressed against the surface of the reference roll 70 with the fluid ejected from the fluid ejecting nozzle 80. However, if the fluid pressure is too high, the film 6a will flutter on the reference roll 70, and conversely if too low, the film 6a will not adhere to the reference roll 70 and the thickness measured by the thickness meter will be inaccurate. End up.

  As a result, accurate thickness measurement is not performed in the first place. Thickness is measured with a thickness meter, and this is used to control the cooling state (cooling air volume, temperature, etc.) with the cooling air, resulting in uneven thickness. There was a problem that it was difficult to prevent the problem.

  In view of the problems in the conventional inflation film production apparatus described above, the present invention is simple and effective that the thickness of the tubular film produced by the inflation film production apparatus is uneven in the circumferential direction. And it aims at providing the inflation film manufacturing apparatus which can prevent at low cost.

  In order to solve the above-mentioned problems, the present application is arranged on the outer periphery of a tube-shaped molten synthetic resin extruded from the circular slit of the molding die at a position surrounding the circular slit above the molding die. In an inflation film manufacturing apparatus for manufacturing a tubular film by blowing cooling air from an air ring to cool the tubular synthetic resin, an inflation film manufacturing apparatus having the following configuration is proposed.

  A first aspect is the above-described inflation film manufacturing apparatus, wherein the air ring surrounds the cooling air intake on the outer peripheral side, surrounds the tubular molten synthetic resin on the center side, and surrounds the outer periphery of the tubular molten synthetic resin. An annular cooling air outlet that blows cooling air introduced from the cooling air inlet toward the cooling air inlet, and is formed toward the cooling air outlet side starting from a position where the cooling air inlet is provided. The cooling air flow path is a spiral cooling air flow path formed by a spiral partition plate that gradually decreases in diameter starting from the position where the cooling air intake port is provided. In addition, the height of the spiral partition plate gradually decreases from the position where the cooling air intake is provided.

  A second form is the above-described inflation film manufacturing apparatus, wherein the air ring surrounds the cooling air intake on the outer peripheral side, the tube-shaped molten synthetic resin on the center side, and on the outer periphery of the tube-shaped molten synthetic resin. An annular cooling air outlet that blows cooling air introduced from the cooling air intake toward the annular cooling air outlet is formed by a small-diameter inner ring portion and a large-diameter outer ring portion. A plurality of radiant heating heaters, each of which can be individually temperature-adjusted, are spaced apart from adjacent radiant heaters on the upper side of the outer ring portion in the circumferential direction. Are deployed.

  In a third embodiment, in the inflation film manufacturing apparatus, the air ring surrounds the cooling air intake on the outer peripheral side, surrounds the tubular molten synthetic resin on the center side, and surrounds the outer periphery of the tubular molten synthetic resin. An annular cooling air outlet that blows the cooling air introduced from the cooling air inlet toward the cooling air inlet, and has a cooling air flow path between the cooling air inlet and the cooling air outlet, the cooling air flow The passage has a plurality of through holes, and an annular rectifying member that allows the cooling air to flow from the cooling air inlet to the annular cooling air outlet only through the plurality of through holes is provided in the annular cooling air blowing. A plurality of heating elements that can be individually temperature-adjusted over the entire circumference of the annular rectifying member are arranged in a circumferential direction between adjacent heating elements. Those that are deployed at intervals.

  In a fourth embodiment, the inflation film manufacturing apparatus includes a thickness gauge for measuring the thickness of the manufactured tubular film, and the thickness gauge is formed by cutting the manufactured tubular film 2 Measuring the thickness of each flat film formed into a sheet, and conveying means for conveying each of the flat films cut into two sheets facing each other in the longitudinal direction; The detector is provided with a detection surface on the side, and is arranged so as to be movable in the lateral direction between two flat films conveyed in the longitudinal direction facing each other, and the detection surface of the detector is opposed to each other A rotating mechanism that rotates 180 degrees from a state facing one of two flat films to a state facing the other.

  In a fifth embodiment, the inflation film manufacturing apparatus includes a thickness meter for measuring the thickness of the manufactured tubular film, and the thickness meter is formed by cutting the manufactured tubular film 2 The thickness of each flat film made into a sheet is measured, and the flat roll film is cut and cut into two sheets, and the flat roll film is brought into contact with the reference roll surface while the reference roll surface. It is a non-contact measurement sensor that measures the thickness of a film that is in contact with the surface in a non-contact manner. A suction means is provided.

  According to the inflation film manufacturing apparatus of the present invention, it is possible to easily and effectively prevent the occurrence of deviation in the circumferential direction in the thickness of the tubular film manufactured by the inflation film manufacturing apparatus at a low cost.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(Example 1)
A first preferred embodiment of the present invention will be described with reference to FIGS.

  The inflation film manufacturing apparatus according to this embodiment prevents the occurrence of bias in the thickness of the tubular film manufactured by the inflation film manufacturing apparatus by improving the air ring portion.

  FIG. 4 illustrates the schematic configuration of the inflation film manufacturing apparatus 1 of this embodiment.

  From the air ring 10 provided on the outer periphery of the tubular molten synthetic resin 5 extruded in the direction of the arrow 21 from the circular slit 2a of the molding die 2 at a position surrounding the circular slit 2a above the molding die 2. Cooling air is blown to cool the tube-shaped molten synthetic resin 5 to produce a tube-shaped film 6. At this time, the tube-shaped molten synthetic resin 5 may be expanded by blowing the internal air supplied as indicated by the arrow 22 from the center of the molding die 2 at a predetermined pressure.

  The tube-shaped molten synthetic resin 5 is, for example, a thermoplastic synthetic resin such as low density polyethylene (LDPE) in a molten state.

  As shown in FIGS. 1 and 2, the air ring 10 includes a cooling air inlet 12 on the outer peripheral side and a cooling air outlet 13 surrounding the tube-shaped molten synthetic resin 5 on the center side. From the cooling air outlet 13, the cooling air introduced into the cooling air inlet 12 as shown by an arrow 23 from a blower (not shown) is blown toward the outer periphery of the tube-shaped molten synthetic resin 5. A cooling air passage 15 is formed between the cooling air inlet 12 and the cooling air outlet 13.

  When the cooling air blown out from the cooling air outlet 13 hits the peripheral surface of the tubular molten synthetic resin 5, the tubular molten synthetic resin 5 is cooled, and the tube-shaped fill 6 formed by solidifying the tube-shaped molten synthetic resin 5 is stable. The plate 20 is crushed into a flat shape and taken up by the pinch roll 4. And thickness is measured with the thickness meter 24, and it winds up as a product with the winder which is not shown in figure.

  Using the information about the thickness of the tubular film 6 measured by the thickness gauge 24, the controller 25 issues a control command to the air ring 10 and the like, and the state of the cooling air (for example, the air volume and temperature of the cooling air) is set. Control. In the controller 25, for example, a control program stored in a microcomputer and a ROM is provided, and the above-described control is performed based on the measurement information of the thickness gauge 24. For example, as shown in FIG. 1 and FIG. 2, the amount of air blown from the blower to the cooling air intakes 12 arranged in plural is individually adjusted, or the temperature of the cooling air is changed to the circumference at the annular cooling air outlet 13. Control such as adjustment for each predetermined position in the direction is performed. That is, such control can be performed corresponding to the position in the circumferential direction of the tubular molten synthetic resin 5 in which the thickness of the tubular fill 6 is uneven.

  As shown in FIG. 4, the tube-shaped molten synthetic resin 5 extruded from the die slit 2a in the direction of the arrow 21 is stretched in the flow direction (the direction of the arrow 21) at the speed V2 of the pinch roll 4 faster than the extrusion speed V1. At the same time, it is stretched in the circumferential direction to the diameter D2 of the tubular synthetic resin film 6 larger than the diameter D1 of the die slit 2a by the pressure of the internal air blown from the center of the molding die 2.

  For this reason, the thickness of the tube-shaped film 6 which became a product by cooling and solidifying becomes thinner than the thickness of the tube-shaped molten synthetic resin 5 when extruded from the die slit 2a.

  The cooling air blown from the cooling air outlet 13 of the air ring 10 is blown to the peripheral surface to be cooled and solidified, but the tube-like fill 6 does not become thinner any more, but is solidified immediately after being extruded from the die slit 2a. The part which has not been made thin by stretching in the flow direction described above or stretching in the circumferential direction.

  Therefore, if the amount of the cooling air blown from the cooling air outlet 13 of the air ring 10 varies, the tubular molten synthetic resin 5 is not cooled uniformly in the circumferential direction, so that the tube-shaped film 6 having a large uneven thickness. Become.

  In the inflation film manufacturing apparatus 1 of the present invention for preventing this, an air ring 10 shown in FIGS. 1 and 2 is employed.

  As shown in FIGS. 1 and 2, the air ring 10 includes a plurality (two in the illustrated example) of cooling air intakes 12 on the outer peripheral side. And the cooling wind flow path 15 currently formed toward the cooling wind blower outlet 13 side is provided from the position where each cooling wind inlet 12 is arranged.

  The cooling air flow path 15 starts from the position where the cooling air intakes 12 and 12 are arranged, and is a spiral formed by spiral partition plates 14 and 14 that gradually decrease in diameter as shown in FIG. It is a cooling air flow path of a shape.

  Here, as shown in FIG. 1, the height of the spiral partition plates 14 and 14 gradually decreases from the position where the cooling air intakes 12 and 12 are provided. In the illustrated example, the height of the spiral partition plate starts from the position where the cooling air intake 12 is provided so that the height of the spiral partition plate 14 on the center side finally becomes zero. As it gets lower gradually.

  Therefore, as shown in FIG. 2, the cooling air supplied to the cooling air intake 12 flows in the spiral cooling air flow path 15 to the end thereof as indicated by arrows 26a, 26b, 27a, 27b. Go. And it blows on the surrounding surface of the tube-shaped molten synthetic resin 5 from the cyclic | annular cooling wind blower outlet 13, as shown in FIG.

  Further, the cooling air flowing in the spiral cooling air flow path 15 is gradually lowered as the height of the spiral partition plate 14 advances, so that a constant rate is obtained as shown in FIG. It overflows from the cooling air flow path 15 and gradually flows in the direction of the center side as indicated by an arrow 28 from the gap between the upper edge of the partition plate 14 and the lower side surface of the top plate 11.

  Accordingly, the cooling air blown from the annular cooling air outlet 13 toward the outer periphery of the tubular molten synthetic resin 5 toward the center of the tubular molten synthetic resin 5 is the circumference of the tubular molten synthetic resin 5. It is possible to blow out at a uniform air volume and speed in the direction.

  FIG. 3 shows an annular cooling at each position in the circumferential direction of the tube-shaped molten synthetic resin 5 in the inflation film manufacturing apparatus 1 of the present invention having the air ring 10 shown in FIGS. The result of having measured the wind speed of the cooling air which blows off from the wind blower outlet 13 is represented. In FIG. 3, the positions indicated by reference numerals 12 and 12 are the positions of the cooling air intakes. The cooling air flows from the annular cooling air outlet 3 at substantially the same air speed at any position in the circumferential direction. Was blown out.

  That is, according to the inflation film manufacturing apparatus 1 of this embodiment, the cooling air supplied to the cooling air inlet 12 is blown out from the annular cooling air outlet 13 in a state where the wind speed does not vary in the circumferential direction. Therefore, the tube-shaped molten synthetic resin 5 can be cooled with cooling air having no variation in wind speed in the circumferential direction. Thereby, the uneven thickness of the manufactured tubular film 6 can be minimized, and the film 6 having a uniform thickness in the circumferential direction can be manufactured.

  In this embodiment, it is also possible to increase the number of cooling air intakes 12 and increase the number of partition plates 14 accordingly. Further, a plate having a hole in the upper opening of the spiral cooling air flow path 15 may be disposed.

(Example 2)
A second preferred embodiment of the present invention will be described with reference to FIGS.

  The inflation film manufacturing apparatus according to this embodiment also prevents the occurrence of bias in the thickness of the tubular film manufactured by the inflation film manufacturing apparatus by adding improvements to the air ring portion.

  Constituent members common to the constituent members in the drawings describing the first embodiment are given the same reference numerals, and the description thereof is omitted.

  As described in the first embodiment, the tube-shaped molten synthetic resin 5 extruded from the die slit 2a in the direction of the arrow 21 is stretched in the flow direction (the direction of the arrow 21) at the speed V2 of the pinch roll 4 faster than the extrusion speed V1. At the same time, the tube is stretched in the circumferential direction to the diameter D2 of the tubular synthetic resin film 6 larger than the diameter D1 of the die slit 2a by the pressure of the internal air blown from the center of the molding die 2. That is, the cooling air blown from the cooling air outlet 13 of the air ring 10 is blown to the peripheral surface to be cooled and solidified, but the tube-like fill 6 is not further thinned, but immediately after being pushed out from the die slit 2a. The non-solidified portion is thinned by stretching in the flow direction as described above or stretching in the circumferential direction.

  Therefore, if the temperature in the circumferential direction of the tube-shaped molten synthetic resin 5 varies, the tube-shaped molten synthetic resin 5 does not solidify uniformly in the circumferential direction, resulting in a tube-shaped film 6 having a large uneven thickness. End up.

  In the blown film manufacturing apparatus 1 of the present invention for adjusting the temperature in the circumferential direction of the tubular molten synthetic resin 5, an air ring 30 shown in FIGS. 5 and 6 is employed.

  The air ring 30 surrounds the plurality of cooling air intakes 12, 12 on the outer peripheral side, the tubular molten synthetic resin 5 on the center side, and faces the outer periphery of the tubular molten synthetic resin 5. It is the same as that of the said Example 1 in the point provided with the cyclic | annular cooling wind blower outlet 13 which blows the cooling wind introduce | transduced from as shown by the arrow 32 (FIG. 7). In the illustrated example, two cooling air intakes 12 are provided.

  In the air ring 30 in the inflation film manufacturing apparatus 1 of this embodiment, as shown in FIG. 5, the annular cooling air outlet 13 is formed by a small-diameter inner ring portion 13b and a large-diameter outer ring portion 13a. Has been.

  As shown in FIGS. 5 and 6, a plurality of radiant heaters 31 are provided on the upper side of the outer ring portion 13a over the entire circumference of the outer ring portion 13a. Are arranged at predetermined intervals in the circumferential direction. The plurality of radiant heaters 31 can be individually adjusted in temperature.

  A preferable example of the radiation heating type heater 31 is a far infrared type heater having the same wavelength as the absorption wavelength of the tube-shaped molten synthetic resin 5.

  By making the radiation heating type heater 31 a far infrared type heater having the same wavelength as the absorption wavelength of the tube-shaped molten synthetic resin 5, the tube-shaped molten synthetic resin 5 can be directly and efficiently heated.

  The radiant heating type heaters 31 can be individually adjusted in temperature, and a plurality of the radiant heating type heaters 31 are arranged at predetermined intervals in the circumferential direction of the annular cooling air outlet 13 as shown in FIG. Therefore, it is possible to adjust the temperature only at a target portion of the tube-shaped molten synthetic resin 5. At this time, since the tube-shaped molten synthetic resin 5 has poor heat conduction, heat is hardly transmitted to a portion adjacent in the circumferential direction. Therefore, by controlling the temperature of only necessary portions of the plurality of radiant heaters 31, it is possible to accurately control only the target portion of the tubular molten synthetic resin 5 as desired.

  Thus, the temperature of only the intended portion of the tubular molten synthetic resin 5 can be directly and efficiently adjusted without affecting other portions adjacent to the circumferential direction in the tubular molten synthetic resin 5. Thereby, the thickness in the circumferential direction can be accurately controlled, and the tubular film 6 having a uniform thickness in the circumferential direction can be efficiently manufactured.

  For example, the thickness may be measured by a thickness gauge 24 that measures the thickness of the manufactured film 6, and the data may be used to automatically control the radiant heating type heater 31 via the controller 25. When there is a part thicker than the predetermined thickness of the film 6 measured by the thickness meter 24, the part of the tube-shaped molten synthetic resin 5 at the corresponding position is heated from the other part and stretched before solidifying. Thus, uneven thickness can be suppressed. Further, the radiant heater 31 at a position corresponding to the thick portion may be finely adjusted manually.

  That is, if the temperature of the radiant heater 31 at the position corresponding to the portion of the tubular molten synthetic resin 5 corresponding to the thick portion in the circumferential direction of the tubular film 6 is raised from the heater of the other portion, Since the portion becomes thin, the uneven thickness of the tube-shaped synthetic resin film 6 can be controlled.

  A reflection plate may be provided behind the radiant heating type heater 31, or a resistance heating type heater may be used instead of the radiant heating type heater 31.

  Further, a radiation heating heater 31 may be installed inside the tube-shaped molten synthetic resin 5.

  As described above, in the present embodiment, a plurality of radiation heating heaters 31 that can be individually adjusted in temperature are provided at the annular cooling air outlet 13 of the air ring 30 installed around the tube-shaped molten synthetic resin 5. A plurality of them were arranged at predetermined intervals in the circumferential direction. Therefore, the temperature of the tube-shaped melted synthetic resin 5 can be adjusted in a fine and optimal manner in the circumferential direction in response to the uneven thickness of the tube-shaped film 6. Minimize efficiently.

(Example 3)
A third preferred embodiment of the present invention will be described with reference to FIGS.

  The inflation film manufacturing apparatus according to this embodiment also prevents the occurrence of bias in the thickness of the tubular film manufactured by the inflation film manufacturing apparatus by adding improvements to the air ring portion.

  Constituent members common to the constituent members in the drawings describing the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted.

  In this embodiment, as shown in FIG. 11, the manufactured tube-shaped film 6 is cut by a cutting blade 9 to form two flat films 6a and 6b, and then the respective thicknesses thereof are reduced. The thickness is measured by the thickness gauge 24, and then wound as a product on a winder (not shown).

  As described in Example 2, if the temperature of the tube-shaped molten synthetic resin 5 varies in the circumferential direction, the tube-shaped molten synthetic resin 5 does not solidify uniformly in the circumferential direction, and the uneven thickness is large. It becomes the tube-shaped film 6.

  An air ring 40 shown in FIGS. 8 to 10 is employed in the inflation film manufacturing apparatus 1 of the present invention for adjusting this.

  The air ring 40 surrounds the cooling air intake 12 on the outer peripheral side, surrounds the tubular molten synthetic resin 5 on the center side, and is introduced from the cooling air intake 12 toward the outer periphery of the tubular molten synthetic resin 5. As in the case of the first and second embodiments, the annular cooling air outlet 13 for blowing the wind is provided, and the cooling air passage 15 is provided between the cooling air inlet 12 and the cooling air outlet 13. is there.

  An annular rectifying member 41 is disposed in the cooling air passage 15 so as to surround the annular cooling air outlet 13.

  The annular rectifying member 41 has a plurality of through holes 42, and cooling air can flow from the cooling air intake 12 toward the annular cooling air outlet 13 only through the plurality of through holes 42.

  The plurality of through holes 42 rectify the cooling air introduced from the cooling air inlet 12 and blow out from the annular cooling air outlet 13 at a uniform flow rate and wind speed, and at a uniform flow rate and wind speed in the circumferential direction. It is provided in order to effectively realize that it is sprayed on the outer periphery of the tube-shaped molten synthetic resin 5. Therefore, as shown in FIGS. 9 and 10, it is desirable that the through holes 42 are evenly provided at predetermined intervals in the circumferential direction of the annular rectifying member 41.

  In addition, a plurality of heating elements 43 are arranged on the annular rectifying member 41 with a predetermined interval between adjacent heating elements 43 over the entire circumference. The plurality of heating elements 43 can be individually adjusted in temperature. In the illustrated embodiment, a plurality of electric heaters whose temperatures can be individually adjusted are embedded at predetermined intervals in the circumferential direction over the entire circumference of the annular rectifying member 41.

  Therefore, when the cooling air passes through the through holes 42 provided in the annular rectifying member 41, the heating element 43 provided in a large number as described above takes into consideration the thickness of the manufactured film 6 and Individually controlled to the desired temperature in the direction.

  In this control, the thickness is measured by a thickness meter 24 for measuring the thickness of the manufactured film 6, and the individual heating elements 43 are automatically controlled via the controller 25 using the data. It can be carried out.

  For example, based on the information of the thickness gauge 24 that measures the thickness of the manufactured film 6, the cooling air is supplied to the heating element 43 at the position corresponding to the thick part of the film 6 via the controller 25. The energization is controlled from the controller 25 so as to raise the temperature. That is, when there is a part thicker than the predetermined thickness of the film 6 measured by the thickness meter 24, the temperature of the cooling air for cooling the corresponding part of the molten synthetic resin 5 is raised to cool the other part. If the speed is slowed down, it can be stretched before solidification, so uneven thickness can be suppressed. Thereby, the portion of the tube-shaped melted synthetic resin 5 is thinned, the uneven thickness is small, and the film 6 having a uniform thickness in the circumferential direction can be manufactured.

  The heating element 43 is preferably embedded in an annular rectifying member 41 provided with a plurality of through holes 42 at predetermined intervals in the circumferential direction. It may be attached to the surface. Further, the annular rectifying member 41 itself having a plurality of through holes 42 may be used as the heating element 43.

  According to this embodiment, since the annular rectifying member 41 includes a plurality of through holes 42 at predetermined intervals in the circumferential direction, the contact area between the cooling air and the annular rectifying member 41 is large. Therefore, the heat transfer efficiency from the heating element 43 that can be individually adjusted to the cooling air is good, the temperature of the cooling air can be partially controlled in the circumferential direction of the annular rectifying member 41 with less energy, and the uneven thickness of the film 6 can be reduced. It can be adjusted efficiently.

Example 4
A fourth preferred embodiment of the present invention will be described with reference to FIGS.

  The inflation film manufacturing apparatus according to this embodiment has a deviation in the thickness of the tubular film manufactured by improving the air ring portion, like the above-described inflation film manufacturing apparatus in the first to third embodiments. Is provided with a thickness meter that can measure the thickness of the tubular film at low cost, and as a result, the inflation film manufacturing apparatus provided with the uneven thickness prevention mechanism described in Examples 1 to 3 is provided at low cost. It is something that can be done.

  Constituent members common to the constituent members in the drawings describing the first to third embodiments are denoted by the same reference numerals, and description thereof is omitted.

  The thickness gauge 24 provided in the inflation film manufacturing apparatus of this embodiment is configured so that the manufactured tube-shaped film 6 is cut open by the cutting blade 9 to form two flat films 6a and 6b. Is to measure.

  The thickness gauge 24 is a conveying means for conveying the flat films 6a and 6b cut and opened by the slitting blade 9 in the longitudinal direction so as to face each other, for example, conveying rollers 51, 52, 53, 54, 55 and 56 are provided.

  The thickness gauge 24 includes a detector 58 having a detection surface 57 on one side as shown in FIG.

  The detector 58 is opposed to each other in the longitudinal direction (vertical direction in FIG. 12, direction perpendicular to the drawing in FIG. 13) between the two flat films 6a and 6b in the lateral direction ( In FIG. 13, it is arranged so as to be movable in the direction indicated by X.

  The thickness meter 24 rotates the detection surface 57 of the detector 58 by 180 degrees from a state facing one of the two flat films 6a and 6b facing each other to a state facing the other. It has.

  Specifically, as shown in FIGS. 12 to 14, a rail 61 is attached to the frame 60 so as to be orthogonal to the direction in which the films 6a and 6b are conveyed. In this way, traverse is reversible in the direction of arrow X (FIG. 13) and the direction of arrow Y (FIG. 14) on the rail 61 arranged in the lateral direction (the direction indicated by X in FIG. 13). A device 62 is provided. A long screw 63 is screwed to the traverse device 62, and a traverse motor 64 is coupled to the long screw 63.

  On the traverse device 62, the direction of the detection surface 57 of the detector 58 is rotated 180 degrees in the direction of the arrow Z. That is, the detection surface 57 of the detector 58 is placed on one of the two films 6a and 6b facing each other. A turning device 65 is attached to rotate 180 degrees from the facing state to the other. A rotation motor 66 is attached to the rotation device 65.

  As shown in FIGS. 13 and 14, reflectors 67a and 67b that reflect infrared rays emitted from the detector 58 are opposed to the detection surface 57 of the detector 58 behind the films 6a and 6b. Arranged.

  The films 6a and 6b cut into two sheets pass between the frame 60 and the reflectors 67a and 67b, and are conveyed in the direction perpendicular to the paper surface in FIGS. 13 and 14, that is, in the vertical direction in FIG. In FIG. 15, the toner is conveyed toward the downstream conveying rollers 54, 55 and 56.

  As shown in FIG. 13, first, the detection surface 57 of the detector 58 is directed in the direction of the film 6a, and the detector 58 is hatched in the width direction of the flat film 6a, that is, in the direction of the arrow X, hatched with diagonal lines. The traverse device 62 moves to the end. During this lateral movement, the detector 58 emits infrared rays and captures the amount of infrared rays reflected from the reflecting plate 67a, measures the thickness of the film 6a, and detects the thickness deviation (thickness variation) of 6a. To detect.

  Next, as shown in FIG. 14, at the left lateral end in the figure, the direction of the detection surface 57 of the detector 58 is rotated 180 degrees in the arrow Z direction, and the detection surface 57 of the detector 58 is moved over the film 6a. Directed toward the film 6b facing the.

  Then, the detector 58 is moved laterally in the direction of the arrow Y, and the uneven thickness of the film 6b is detected by the same operation as described above.

  According to the thickness gauge 24 provided in the insulation film manufacturing apparatus of this embodiment, as described above, the film 6a cut into two sheets with one detector without using two detectors, The thickness of 6b can be measured. Therefore, it is economical and the structure is simple. Therefore, it is compact and easy to use.

  In the above description, an example in which a detector using infrared rays is used as the detector 58 has been described. Instead, a capacitance type detector as described in International Publication No. WO98 / 14751 is used. You may do it.

  In any case, a detector having a detection surface on one side is moved laterally between two flat films 6a and 6b conveyed in the longitudinal direction so as to face each other, and the detector If the detection surface is rotated 180 degrees from the state facing one of the two flat films 6a, 6b facing each other to the state facing the other, two detectors should be used. The thickness of the films 6a and 6b cut into two sheets can be measured with one detector.

(Example 5)
A fifth preferred embodiment of the present invention will be described with reference to FIGS.

  The inflation film manufacturing apparatus according to this embodiment has a deviation in the thickness of the tubular film manufactured by improving the air ring portion, like the above-described inflation film manufacturing apparatus in the first to third embodiments. Is provided with a thickness meter that can measure the thickness of the tubular film more accurately, and as a result, it is possible to more reliably prevent uneven thickness in the inflation film manufacturing apparatus described in Examples 1 to 3 described above. Is.

  Constituent members common to the constituent members in the drawings describing Examples 1 to 4 are denoted by common reference numerals, and the description thereof is omitted.

  The thickness gauge 24 provided in the inflation film manufacturing apparatus of this embodiment is configured so that the manufactured tube-shaped film 6 is cut open by the cutting blade 9 to form two flat films 6a and 6b. Is to measure.

  The thickness gauge 24 solves the problems of the thickness gauge provided in the conventional inflation film manufacturing apparatus described with reference to FIG. 24, and the conventional inflation film manufacturing apparatus described with reference to FIG. Constituent members common to the thickness gauges provided are assigned common reference numerals, and description thereof is omitted.

  As described with reference to FIG. 24, the thickness gauge is configured so that the flat film 6a, 6b cut into two pieces is brought into contact with the reference roll surface 70 while the film 6a is in contact with the thickness. It is a non-contact measurement sensor that measures the thickness by irradiating the laser beam 71 from the tangential direction of the surface of the reference roll 70. That is, the thickness gauge is a non-contact measurement sensor that measures the thickness of the film 6a that is running on the reference roll surface 70 in a non-contact manner.

  And, in the vicinity of the portion where the film 6a and the surface of the reference roll 70 are in contact, as shown in FIG. 16, there is provided a suction means 73 for reducing the pressure of the contact portion between the film 6a and the surface of the reference roll 70. It is.

  In this way, the air between the reference roll 70 and the film 6a is sucked in by a blower (not shown) through the suction means 73, and the air pressure in this portion is made negative, thereby bringing the film 6a into close contact with the reference roll 70. ing. That is, the vicinity of the portion where the reference roll 70 and the film 6a are in contact with each other is reduced by reducing the pressure.

  According to this embodiment, since the film 6a is securely brought into close contact with the reference roll 70 by the suction force of the suction means 73, the thickness of the film 6a can be accurately detected.

  Since accurate thickness measurement can be performed in this way, the mechanism described in Examples 1 to 3 is used to precisely control the cooling state (cooling air volume, temperature, etc.) with cooling air, The occurrence of uneven thickness can be more reliably prevented.

  In this embodiment, a laser beam shading type detector is used as a non-contact measurement sensor for measuring the thickness of the film 6a that is in contact with the reference roll surface 70 in a non-contact manner. Various non-contact measurement sensors such as a laser and an ultrasonic reflection type detector can be employed in place of the beam shielding type detector.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the embodiments, and various technical scopes can be obtained from the description of the scope of claims. It is possible to change to the form.

Sectional drawing of the air ring in 1st embodiment of the inflation film manufacturing apparatus of this invention. FIG. 1 is a cross-sectional view taken along line II in FIG. The figure showing the result of having measured the wind speed of the cooling air which blows off from a cyclic | annular cooling air blower outlet in the inflation film manufacturing apparatus of this invention provided with the air ring of FIG. 1, FIG. The figure showing schematic structure of 1st embodiment of the inflation film manufacturing apparatus of this invention. The figure which represented and expressed a part of air ring part in 2nd embodiment of the inflation film manufacturing apparatus of this invention. The VV sectional view taken on the line in FIG. The figure showing schematic structure of 2nd embodiment of the inflation film manufacturing apparatus of this invention. The figure which carried out the cross section and demonstrated the air ring part in 3rd embodiment of the inflation film manufacturing apparatus of this invention. VIII-VIII sectional view taken on the line in FIG. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. The figure showing schematic structure of 3rd embodiment of the inflation film manufacturing apparatus of this invention. The front view which abbreviate | omitted and represented a part of thickness meter in 4th embodiment of the inflation film manufacturing apparatus of this invention. The top view which abbreviate | omitted and represented a part explaining the operation state of the thickness meter of FIG. The top view which abbreviate | omitted and represented a part explaining the other operation state of the thickness meter of FIG. 12 illustration. The figure showing schematic structure of 4th embodiment of the inflation film manufacturing apparatus of this invention. The side view which abbreviate | omitted and represented a part of thickness meter in 5th embodiment of the inflation film manufacturing apparatus of this invention. The figure showing schematic structure of 5th embodiment of the inflation film manufacturing apparatus of this invention. The figure explaining the cross section of the air ring part in the conventional inflation film manufacturing apparatus. FIG. 18 is a cross-sectional view of the XVIII-XVIII line portion in FIG. The figure showing the result of having measured the wind speed of the cooling wind which blows off from the cyclic | annular cooling wind blower outlet in the conventional inflation film manufacturing apparatus provided with the air ring of FIG. 18, FIG. The perspective view explaining the air ring part in the other conventional inflation film manufacturing apparatus. The figure which carried out the cross section and demonstrated the air ring part in the other conventional inflation film manufacturing apparatus. The top view explaining the operation state of the thickness meter provided in the conventional inflation film manufacturing apparatus. The side view explaining the operation state of the other thickness meter provided in the conventional inflation film manufacturing apparatus.

Claims (5)

Cooling air is blown from the air ring provided at a position surrounding the circular slit above the molding die to the outer periphery of the tubular molten synthetic resin extruded from the circular slit of the molding die. A blown film production apparatus for producing a tubular film by cooling the molten synthetic resin of
The air ring surrounds the cooling air intake on the outer peripheral side, surrounds the tubular molten synthetic resin on the center side, and receives the cooling air introduced from the cooling air intake toward the outer periphery of the tubular molten synthetic resin. It has an annular cooling air outlet to be blown, and a cooling air passage formed toward the cooling air outlet side starting from the position where the cooling air inlet is provided,
The cooling air flow path is a spiral cooling air flow path formed by a spiral partition plate whose diameter gradually decreases starting from the position where the cooling air intake port is provided,
The inflation film manufacturing apparatus, wherein the height of the spiral partition plate gradually decreases from a position where the cooling air intake is provided. Cooling air is blown from the air ring provided at a position surrounding the circular slit above the molding die to the outer periphery of the tubular molten synthetic resin extruded from the circular slit of the molding die. A blown film production apparatus for producing a tubular film by cooling the molten synthetic resin of
The air ring surrounds the cooling air intake on the outer peripheral side, surrounds the tubular molten synthetic resin on the center side, and receives the cooling air introduced from the cooling air intake toward the outer periphery of the tubular molten synthetic resin. It has an annular cooling air outlet that blows,
The annular cooling air outlet is formed by a small diameter inner ring portion and a large diameter outer ring portion,
On the upper side of the outer ring part, a plurality of radiant heaters that can be individually temperature-controlled over the entire circumference of the outer ring part are arranged with a predetermined interval in the circumferential direction between adjacent radiant heaters. An inflation film manufacturing apparatus characterized by Cooling air is blown from the air ring provided at a position surrounding the circular slit above the molding die to the outer periphery of the tubular molten synthetic resin extruded from the circular slit of the molding die. A blown film production apparatus for producing a tubular film by cooling the molten synthetic resin of
The air ring surrounds the cooling air intake on the outer peripheral side, surrounds the tubular molten synthetic resin on the center side, and receives the cooling air introduced from the cooling air intake toward the outer periphery of the tubular molten synthetic resin. It has an annular cooling air outlet for blowing, and has a cooling air flow path between the cooling air inlet and the cooling air outlet,
The cooling air flow path has a plurality of through holes, and the annular rectifying member that allows the cooling air to flow from the cooling air inlet to the annular cooling air outlet only through the plurality of through holes. It is deployed around the annular cooling air outlet,
The annular rectifying member is provided with a plurality of heating elements, each of which can be individually temperature-adjusted, at a predetermined interval in the circumferential direction between adjacent heating elements over the entire circumference. Inflation film manufacturing equipment. Cooling air is blown from the air ring provided at a position surrounding the circular slit above the molding die to the outer periphery of the tubular molten synthetic resin extruded from the circular slit of the molding die. A blown film production apparatus for producing a tubular film by cooling the molten synthetic resin of
It is equipped with a thickness meter that measures the thickness of the manufactured tubular film,
The thickness gauge measures the thickness of each flat film formed by cutting the produced tubular film into two pieces,
Transport means for transporting the flat films cut into two pieces in the longitudinal direction to face each other;
A detector provided with a detection surface on one side and arranged so as to be movable laterally between two flat films conveyed in the longitudinal direction opposite to each other;
An inflation film comprising: a rotation mechanism that rotates a detection surface of the detector 180 degrees from a state in which the detection surface faces one of two opposed flat films to a state in which the detection surface faces the other. Manufacturing equipment. Cooling air is blown from the air ring provided at a position surrounding the circular slit above the molding die to the outer periphery of the tubular molten synthetic resin extruded from the circular slit of the molding die. A blown film production apparatus for producing a tubular film by cooling the molten synthetic resin of
It is equipped with a thickness meter that measures the thickness of the manufactured tubular film,
The thickness gauge measures the thickness of each of the flat films formed by cutting the manufactured tubular film into two sheets, and the flat film formed by cutting the film into two sheets. It is a non-contact measurement sensor that measures the thickness of a film that is running on the reference roll surface in a non-contact manner while causing each film to run on the reference roll surface.
An inflation film manufacturing apparatus, wherein suction means for depressurizing a contact portion between the film and the reference roll surface is disposed near a portion where the film and the reference roll surface are in contact with each other.

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