JPH0699472A - Device for manufacturing tubular film - Google Patents

Abstract

PURPOSE:To provide the title device capable of always uniformly holding the gap dimension of a resin emitting part and capable of easily performing proper resin molding not generating the unevenness of a resin. CONSTITUTION:The adjusting ring 17 constituting a part of the emitting port 10 of a die 8 and making the gap dimension of an emitting part 18 freely variable by the positional alignment of the ring 17 is arranged to the upper part of the die 8 having an emitting port 10 emitting a predetermined molten resin 2 in a predetermined shape and an adjusting motor 23 performing the alignment operation of the adjusting ring 17 is provided. A film thickness sensor 28 measuring the film thickness of the resin 2 emitted from the emitting port 10 is arranged and a control circuit 29 outputting a driving control signal operating the adjusting motor 23 on the basis of the detection signal from the sensor 28 so as to uniformize the gap dimension of the emitting part 18 consisting of the die 8 and the adjusting ring 17 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tubular film manufacturing apparatus, and more particularly to a tubular film for forming a film having a predetermined shape by discharging a molten resin supplied by an extruder from a discharge port of a die. Manufacturing equipment.

[0002]

2. Description of the Related Art Generally, a resin such as a thermoplastic resin which is charged from an hopper by an extruder is melted while being transported by a screw conveyor in a closed cylinder, and then the molten resin is formed into a die having a predetermined shape. A tubular film manufacturing apparatus is widely used in which a desired tubular film is molded by extruding the molten resin into a tubular shape through the die discharge port.

FIG. 2 shows such a conventional tubular film manufacturing apparatus. On the upper surface of the extruder 1, a hopper for supplying a predetermined resin 2 into a cylinder 3 inside the extruder 1. 4, a screw conveyor 6 that conveys the resin 2 supplied from the hopper 4 toward a head 5 having an extrusion port, and a head from the screw conveyor 6 are installed inside the extruder 1. A heater (not shown) for melting the resin 2 conveyed to 5 is incorporated. A feed pipe 7 bent upward is connected to the upper surface of the head 5 of the extruder 1, and a die 8 for forming a tubular film is provided at the tip of the feed pipe 7. The inlet part 9 is detachably connected. An annular ejection port 10 for ejecting the molten resin 2 into a thin film cylinder is formed on the upper portion of the die 8.
An air ejection port 11 is formed on the inside of the ejection port 10 of the die 8. Further, an air supply port 12 communicating with the air ejection port 11 is provided on the lower surface of the die 8, and air is sent from the air supply port 12 to eject air from the air ejection port 11. The discharge port 10
The resin 2 discharged from is blown up.

A cooling air supply device 13 for cooling the resin 2 discharged in a cylindrical shape from the discharge port 10 is disposed near the upper portion of the die 8 and further above the die 8. Is the resin 2 discharged in a cylindrical shape from the discharge port 10.
A pair of guide plates 14 and 1 for guiding the vehicle so as to be folded flat.
4 are provided. A pair of pinch rollers 15, 15 that pulls up and conveys the planar resin 2 folded by the guide plate 14 is disposed at the upper position of each of the guide plates 14, and the pinch rollers 15 on the side of the pinch rollers 15 are provided. A take-up roller 16 for taking up the resin 2 is arranged on the downstream side.

In the conventional tubular film manufacturing apparatus, the predetermined resin 2 charged from the hopper 4 of the extruder 1 is melted by the heater while being conveyed by the screw conveyor 6, and the extrusion port of the head 5 is discharged. From the die, and then sent to the inlet of the die 8 via the feed pipe 7. Then, by the die 8, the molten resin 2
Is formed into a cylindrical shape and is discharged upward from the discharge port 10, and air is fed from the air supply port 12 into the die 8 to blow air from the molten resin 2 from the air jet port 11 at a predetermined pressure. The resin 2 is blown into the cylindrical film to blow out the resin 2. The discharged resin 2 is used as the cooling air supply device 1
The guide plate 1 is cooled by cooling air blown from the guide plate 1.
While being gradually folded into a planar shape by 4, it is pulled up by the pinch roller 15 and wound up by the winding roller 16.

[0006]

However, in the above-mentioned conventional tubular film manufacturing apparatus, when the dimensional accuracy of the discharge port 10 of the die 8 has an error and the gap size of the discharge port 10 is not uniform, Discharge port 10 of the die 8
When the resin 2 is discharged from the above to perform molding, there is a problem that the film thickness of the blown resin 2 becomes uneven and the resin 2 having uneven thickness is molded.

Therefore, conventionally, an adjusting ring (not shown) is arranged at the discharge port 10 portion of the die, and the position of the adjusting ring is manually adjusted to uniformly adjust the gap size of the discharge port 10. Although there is one that can be done, the discharge port 1 is still dependent on the temperature during the resin molding operation.
Since the gap size of the 0 portion changes, it is not possible to perform proper resin molding having a uniform film thickness, and when the resin 2 has a non-uniform film thickness, the adjustment ring is again read during the molding operation. Therefore, there is a problem that the manufacturing work is extremely troublesome and the manufacturing efficiency is significantly lowered.

The present invention has been made in view of these points, and it is possible to always maintain a uniform gap size at the resin discharge port portion, and easily perform proper resin molding without uneven thickness. It is an object of the present invention to provide a tubular film manufacturing apparatus that can be used.

[0009]

In order to achieve the above object, the tubular film manufacturing apparatus according to the present invention is provided with an extruder for melting and extruding a predetermined resin, and the molten resin is predetermined in the extruder. In a tubular film manufacturing apparatus in which a die having a discharge port for forming and discharging a shape is connected, a gap size of the discharge port is formed by aligning a part of the discharge port of the die on the upper part of the die. And a drive device for aligning the adjustment ring, and a detection device for measuring the film thickness of the resin discharged from the discharge port. A control device is provided which outputs a drive control signal for operating the drive device based on a detection signal from the detection device so that the gap size of the discharge port including the die and the adjustment ring becomes uniform. It is an butterfly.

[0010]

According to the tubular film manufacturing apparatus of the present invention, the film thickness of the resin discharged and blown from the discharge port of the die is detected by the detection device, and then the control device detects the value detected by the detection device. Based on the unevenness of the resin film thickness, the unevenness of the gap of the discharge portion between the adjusting ring and the die is determined, and the driving control signal for aligning the adjusting ring so as to correct the unevenness of the gap is driven by the driving device. The position of the adjusting ring is adjusted by the drive device based on the drive control signal from the control device, whereby the gap of the discharge part can be adjusted, and the blow expansion is performed. It is possible to uniformly adjust the film thickness of the resin used.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG.
The same parts as those in FIG.

FIG. 1 shows an embodiment of a tubular film manufacturing apparatus according to the present invention. A feed pipe 7 is connected to an inlet portion 9 of a tubular film forming die 8. The resin 2 melted in the cylinder of the extruder (not shown) is supplied to the feed pipe 7 through the head. In addition, on the upper part of the die 8,
An annular ejection port 10 for ejecting the molten resin 2 into a thin film cylinder
Is formed, and the inner portion of the discharge port 10 of the die 8 is formed so as to project upward.

An adjusting ring 17 is arranged on the upper surface of the die 8 on the outer peripheral side of the protruding portion so that the upper surface thereof is flush with the upper surface of the protruding portion of the die 8. Between the inner peripheral surface of the adjusting ring 17 and the outer peripheral surface of the protruding portion of the die 8, there is formed a discharge portion 18 which communicates with the discharge opening 10 of the die 8 and constitutes a part of the discharge opening. A flange portion 19 extending downward and covering the upper outer peripheral portion of the die 8 is integrally formed on the outer peripheral portion of the adjusting ring 17, and the flange portion 19 of the adjusting ring 17 is formed.
Adjustment bolts 20 are screwed into the flange portion 19 at a plurality of circumferential positions. Further, an annular motor rail 21 is disposed near the outer peripheral side of the die 8, and a motor support base 22 is provided on the upper surface of the motor rail 21 so as to circulate on the upper surface of the motor rail 21. Is attached to. An adjustment motor 23 as a drive device is mounted on the upper surface of the motor support base 22, and the output shaft 24 of the adjustment motor 23 has the adjustment bolt 20.
A jig 25 for screwing in or out is attached. Further, the jig 25 can move forward and backward with respect to the adjusting bolt 20 so that it can be freely engaged and disengaged.

Inside the discharge port 10 of the die 8, resin supplied from the discharge port 10 by ejecting air supplied from an air supply port 12 provided on the lower surface of the die 8. An air ejection port 11 for blowing and expanding 2 is formed, and the ejection port 1 is provided near the upper portion of the die 8.
A cooling air supply device 13 for cooling the resin 2 discharged from 0 in a cylindrical shape is provided. Further, above the die 8, a pair of guide plates 14, 14 for guiding the resin 2 discharged in a cylindrical shape from the discharge port 10 so as to be folded in a plane are arranged. A pair of pinch rollers 15 and 15 for pulling up and transporting the planar resin 2 folded by the guide plate 14 is disposed at an upper position of 14.
Further, on the downstream side of the pinch roller 15, a winding roller 16 for winding the resin 2 is arranged.

Further, in the present embodiment, an annular sensor rail 26 is disposed between the die 8 and the guide plate 14 so as to be located on the outer peripheral side of the blown resin 2. A sensor support 27 is mounted on the upper surface of the sensor rail 26 so as to be able to orbit the upper surface of the sensor rail 26. On the upper surface of the sensor support base 27, the resin 2 discharged from the discharge port 10 of the die 8 and expanded
A film thickness sensor 28 such as an infrared sensor is mounted as a detection device for measuring the film thickness of the resin 2 based on the output signal from the film thickness sensor 28. A control circuit 29 is connected as a control device that detects the film thickness over the entire circumference of the above, and outputs a control signal for the adjusting motor 23 based on the detected film thickness. Further, the control circuit 29 is connected to a drive circuit 30 which drives the motor support base 22 and the adjustment motor 23 based on a control signal from the control circuit 29.

Next, the operation of this embodiment will be described.

In the present embodiment, the resin 2 melted by the extruder is sent to the die 8 through the feed pipe 7, and the die 8 molds the molten resin 2 into a tubular shape. The air is discharged upward from the discharge port 10 and is fed from the air supply port 12 into the die 8 to jet the air at a predetermined pressure from the air jet port 11 into the cylindrical film made of the molten resin 2. Then, the resin 2 is blown up. The discharged resin 2 is cooled by the cooling air blown from the cooling air supply device 13 and gradually folded into a flat shape by the guide plate 14, while being pulled up by the pinch roller 15 and the winding roller 16 It is designed to be wound up on.

In this case, in this embodiment, the film thickness sensor 28 is operated while the sensor support base 27 is orbitally driven along the sensor rail 26, so that the film thickness of the blown resin 2 is reduced. Measured and this measured value is the control circuit 2
9 is output. Next, the control circuit 29 detects the film thickness in the circumferential direction of the resin 2 based on the measured value of the film thickness, and discharges between the adjustment ring 17 and the die 8 according to the unevenness of the film thickness of the resin 2. The gap unevenness of the portion 18 is determined, and the adjustment motor 2 is provided to the drive circuit 30 so as to correct the gap unevenness.
3 and the drive control signals for the motor support base 22 are output.

Then, the drive circuit 30 moves the motor support base 22 to a predetermined position of the adjusting bolt 20 based on the drive control signal from the control circuit 29, and then the jig 25 of the adjusting motor 23 is handled. The adjustment ring 23 is driven by driving the adjustment motor 23 so that the adjustment bolt 20 is screwed in or out, and this operation is performed for each adjustment bolt 20.
The position of 7 is adjusted.

Thus, the gap of the discharge portion 18 formed between the inner peripheral surface of the adjusting ring 17 and the outer peripheral surface of the protruding portion of the die 8 can be adjusted, and during molding of the resin 2, By repeating the above operation, the film thickness of the blown resin 2 can be adjusted uniformly.

Therefore, in the present embodiment, the film thickness of the resin 2 is measured by the film thickness sensor 28, and the adjusting motor 23 is operated according to the film thickness to adjust the position of the adjusting ring 17, Since the gap size of the discharge part 18 formed by the adjusting ring 17 and the die 8 can be always kept constant, it is possible to always perform resin molding with a uniform film thickness. Further, the film thickness sensor 2
8 and the adjusting motor 23 are always operated, the film thickness can be sequentially and automatically adjusted. As a result, the molding operation can be easily performed, and the working efficiency can be remarkably improved.

In the above embodiment, the film thickness sensor 28 based on infrared rays is used as the detection device. However, for example, a sensor that detects the film thickness by the contact resistance with the resin 2 is used in the guide plate 14 portion. You may Further, as a driving device, each adjusting bolt 20 may be provided with an adjusting motor 23 provided with a jig 25, and all the adjusting bolts 20 may be adjusted and driven simultaneously.
Further, instead of the adjusting bolt 20, the adjusting ring 17 may be driven by using a heat expansion / contraction rod that expands and contracts according to the amount of heat applied.

Further, the present invention is not limited to the above-mentioned embodiment, but various modifications can be made if necessary.

[0024]

As described above, in the tubular film manufacturing apparatus according to the present invention, the position of the adjusting ring is adjusted by measuring the resin film thickness by the detecting device and operating the driving device according to the film thickness. Since adjustment can be performed and the gap size of the discharge port formed by the adjustment ring and the die can be constantly maintained, it is possible to always perform resin molding with a uniform film thickness. Further, by always operating the detection device and the drive device, the film thickness can be sequentially and automatically adjusted, and as a result, the molding operation can be easily performed and the work efficiency can be remarkably improved. And so on.

[Brief description of drawings]

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

FIG. 2 is a schematic configuration diagram showing a conventional tubular film manufacturing apparatus.

[Explanation of symbols]

 2 Resin 8 Die 10 Discharge Port 11 Air Discharge Port 12 Air Supply Port 13 Cooling Air Supply Device 14 Guide Plate 15 Pinch Roller 16 Winding Roller 17 Adjustment Ring 18 Discharge Portion 19 Flange 20 Adjustment Bolt 23 Adjustment Motor 25 Jig 28 Film thickness sensor 29 Control circuit 30 Drive circuit

Claims (1)

[Claims] 1. A tubular film produced by arranging an extruder for melting and extruding a predetermined resin, and connecting a die having a discharge port for molding and discharging the molten resin into a predetermined shape to the extruder. In the apparatus, an adjusting ring is provided on the upper part of the die, which constitutes a part of the discharging port of the die and can adjust the gap size of the discharging port by positioning, and the adjusting ring is operated for positioning. A drive device is provided, a detection device for measuring the film thickness of the resin discharged from the discharge port is provided, and a gap between the discharge port including the die and the adjustment ring is determined based on a detection signal from the detection device. A tubular film manufacturing apparatus comprising a control device for outputting a drive control signal for operating the drive device so that the dimensions are uniform.