JPH08230020A - Extruder output controlling method of continuous extruder and controlling device thereof - Google Patents

Abstract

PURPOSE: To stably extrude polymeric material from an extruder to be connected with a kneader. CONSTITUTION: In the running of an extruder 3, which continuously extrudes polymeric material fed through a chute tube 2 thereto through the rotation of a screw 4, the sojouring state of the polymeric material at the inlet of the extruder 3 is monitored with a monitor camera 8. The image of the monitor camera 8 is inputted in a computer 11 so as to be picture-processed in order to be converted into the stay amount, which indicates the staying state. By inputting the above-mentioned stay amount and the measured values sent from the rotational frequency measuring apparatus 13, the temperature sensor of material 12, and the wattmeter of a motor 14 in a controlling device 15 and the outputting the number-of-rotation setting device 16 of the screw and the driving motor 17 of a material feeder, the number of rotation of the screw and the feeding of polymeric material at the inlet of the extruder are controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an extrusion amount of a continuous extruder and a control apparatus therefor in a process of extruding a polymer material such as a synthetic resin using a continuous kneader and an extruder. It is a thing.

[0002]

2. Description of the Related Art In a process of extruding a polymer material using a continuous kneading machine and an extruder, a chute tube connecting the kneading machine outlet and the extruder inlet is installed to melt and knead the polymer. Feed material to extruder. In the extruder, the screw inside the extruder is rotated by an electric motor and is extruded along the screw.

Japanese Unexamined Patent Publication (Kokai) No. 6-54573 discloses a method of controlling the supply amount and the extrusion amount of the polymer material of the kneader based on the temperature of the polymer material of the kneader and the load state of the motor of the kneader. However, it discloses a control method for one kneader, and does not disclose an operation control method for a continuous extrusion process in which the kneader and the extruder are connected.

[0004]

In order to connect the kneading machine and the extruder and continuously operate them, the control of the retention amount of the polymer material at the polymer material inlet of the extruder is a problem. For example, the retention amount of the polymer material changes depending on the condition change during the normal operation such as the grade change of the polymer material and the clogging of the screen installed on the primary side of the extruder die.
If the retention amount is too large, the polymer material will cool at the inlet, the cooled polymer material will be extruded and the pressure of the polymer material in the extruder will rise, and conversely, if it is too small, surging will occur. Adversely affect the quality of. That is, there is a proper range in which the amount of stay is not a little large and is not small. To continuously extrude within this proper range, change the screw speed of the extruder or change the amount of polymer material supplied to the extruder while observing the retention state of the polymer material at the extruder inlet. However, this monitoring operation must be performed at all times, and the amount of work required is extremely large.

However, in the operation of the extruder connected to the kneading machine, the applicant of the present invention described the prior art which quantifies the retention state of the polymer material at the extruder inlet and describes the continuous automatic operation method of the kneading machine and the extruder. Could not be found.

Therefore, in view of the above points, an object of the present invention is to provide a method for controlling an extrusion amount of a continuous extruder and a control apparatus therefor capable of more preferably automatically controlling extrusion of a polymer material.

[0007]

In order to achieve such an object, the invention of claim 1 connects a polymer material outlet of a kneading machine and a polymer material inlet of an extruder with a chute pipe, In the step of continuously kneading and extruding the molecular material, the residence amount of the polymer material between the polymer material outlet of the kneader and the polymer material inlet of the extruder is measured, and according to the result of the measurement,
The number of revolutions of the extruder screw and / or the supply amount of the polymer material from the kneading machine to the extruder is controlled.

According to a second aspect of the present invention, in addition to the first aspect of the invention, a monitor camera for photographing the polymer material is installed at the polymer material inlet of the extruder, and the monitor camera is obtained from the monitor camera. It is characterized in that an image is input to an image processing apparatus and the amount of retention of the polymer material is measured by image processing of the image processing apparatus.

According to a third aspect of the present invention, a kneading machine and a continuous extruder are connected by a chute pipe, and a continuous amount of the polymer material supplied from the kneading machine to the continuous extruder is controlled. In a control device of a extruder, a retention amount of a polymer material between a polymer material outlet of a kneader and a polymer material inlet of the extruder is measured as one of operation control amounts for controlling the extrusion amount. And a control means for controlling the extrusion amount based on the measured staying amount and other operation control amount.

According to a fourth aspect of the present invention, in addition to the third aspect of the present invention, a photographing means for photographing the polymeric material is installed at the polymeric material inlet of the extruder, and is obtained from the photographing means. The measuring means has an image processing means for performing image processing on the captured image to obtain the retention amount of the polymer material.

[0011]

The present inventor has found that the amount of residence of the polymeric material generated at the inlet of the extruder affects the quality, and based on this finding, the invention of claims 1 and 3 provides continuous extrusion of the polymeric material. The retention amount before the machine is measured, and the screw rotation speed of the extruder and / or the supply amount of the polymer material is controlled according to the measurement result to remove the influence of the retention amount.

According to the second and fourth aspects of the invention, the polymer material is photographed, and the staying amount is acquired from the photographed result.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an example of a control system to which the present invention is applied. In FIG. 1, 1 is a continuous kneader (abbreviated as a kneader), and 2 is a chute tube that connects the outlet of the kneader 1 and the inlet of the extruder 3. The chute tube referred to in the present embodiment is a vertical steel tube that connects the outlet of the kneading machine 1 and the inlet of the extruder 3. Reference numeral 3 is an extruder, 4 is a screw for pushing out a polymer material by rotation, and 5 is an electric motor for rotating the screw 4. Reference numeral 6 is a polymer material supply machine for supplying the polymer material, and 7 is an illumination for illuminating the polymer material inlet of the extruder. Reference numeral 8 is a monitor camera for showing the state of retention of the polymer material at the entrance of the extruder 3, and the image can be seen on the monitor of 9. An image processing board 10 receives image data from the monitor terminal 9.
Reference numeral 11 denotes a computer, which functions as a processing device for the input image data, converts the captured image data into an operation control amount representing a stay amount, and outputs the operation control amount. The operation control amount is a general term for the values of various parameters used to control the equipment of the production facility including the extruder 3. In this embodiment, the amount of retention of the polymer material is one of the operation control amounts. To prepare. The retention amount is a quantitative value obtained from the image processing results, and the retention amount of the polymer material at the extruder inlet, the peak height of the polymer material at the extruder inlet, the area occupancy rate of the polymer material (area of the polymer material / Percentage of extruder inlet area).

Reference numeral 12 is a temperature detector for measuring the temperature of the polymer material in the extruder (one of other operation control amounts), 13 is a screw rotation speed measuring device, and 14 is a power meter of the electric motor 5. The measurement data of these devices are input to the control device 15 together with the retention amount of the polymer material obtained by the image processing.
The control device 15 determines the control content from these input data according to the flowchart of FIG. The rotation speed setting device 16 of the screw 4 of the extruder 3 sets the rotation speed instructed by the control device 15 as the rotation speed of the electric motor 4. Further, an instruction of the number of rotations is sent also to the drive of the feeder and the motor 17.

In such a system configuration, an image of the retention state of the polymer material obtained by the monitor camera 8 installed at the polymer material inlet of the extruder 3 is displayed on the computer 11.
Is image-processed and quantified in the form of various operation control amounts that represent the stay amount. This residence amount of the polymer material, the rotation speed of the screw 4 of the extruder 3 (corresponding to the extrusion amount of the polymer material), the temperature of the polymer material in the extruder 3, and the load state of the electric motor 5 are input to the control device 15. . In the control device 15, according to the set control rule, the screw rotation speed setting device 16 of the extruder 3 and the polymer material feeder drive motor 17
The rotation speed is output to each.

In this embodiment, the rotation speed of the screw 4 and the supply amount of the polymer material (rotation speed of the feeder drive motor 17) are controlled according to the control sequence shown in FIG. That is, when the polymer material temperature is high, the rotation speed of the screw 4 is reduced and the supply amount of the polymer material is reduced (steps S1 to S7 in FIG. 2). Further, the rotation speed of the extruder screw is controlled so that the retention amount of the polymer material falls within an appropriate range (steps S6 to S13 and S14 in FIG. 2).
Furthermore, when the load condition of the electric motor 5 of the extruder 3 is high, the rotation speed of the screw 4 is reduced and the supply amount of the polymer material is reduced (steps S3 to S5 in FIG. 2), which is automatically controlled. .

Next, the method of measuring the staying amount according to the present invention will be described. When the polymer material is photographed at the entrance of the extruder, the polymer material portion is brighter than the background, and the characteristic appears in the brightness of the image. Therefore, the computer 11 extracts a region forming a closed section by the image data whose brightness is in a constant range from the input image data for one screen by using a well-known image processing technique such as a contour line detection method. Since the extracted region becomes an image portion of the polymer material, the peak height of the polymer material is obtained by multiplying the height of the region by a constant coefficient. Further, the area is acquired by counting the number of pixels in the above area, and the area occupancy of the polymer material is calculated from this area.

[0019]

According to the first and third aspects of the present invention, the retention amount of the polymer material before the continuous extruder is measured, and the rotation speed of the extruder screw and / or the polymer material is measured according to the measurement result. By controlling the retention amount, the influence of the retention amount is removed. Thereby, a high quality polymer material can be provided.

According to the second and fourth aspects of the invention, the polymer material is photographed, and the staying amount is obtained from the photographed result. As a result, it becomes possible to measure the retention amount, which has not been performed conventionally.

Further, according to these inventions, the monitoring operation and the operation operation of the extruder operation performed by the operator can be favorably automated, and conventionally there has been a problem that a lot of man-hours are required for these operations. This can be solved, and the man-hours for monitoring and operating the extruder can be significantly reduced. Further, since the polymer material temperature and the load condition of the electric motor can be adjusted to operate within the reference value and the allowable value, the extruder operation can always be stably maintained even when the conditions are changed during normal operation.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration of an embodiment of the present invention.

FIG. 2 is a flowchart showing an example of control rules of the present invention.

[Explanation of symbols]

 1 (Continuous type) Kneader 2 Chute tube 3 (Continuous type) Extruder 4 Screw 5 Electric motor 6 Polymer material feeder 7 Illumination 8 Monitor camera 9 Monitor 10 Image processing board 11 Computer 12 Temperature detector 13 Rotation speed meter 14 Power meter 15 Control device 16 Rotation speed setting device 17 Feeder drive motor

Claims (4)

[Claims] 1. In the step of continuously kneading and extruding a polymer material, the polymer material outlet of the kneader and the polymer material inlet of the extruder are connected by a chute tube, and the polymer material outlet of the kneader is used. The retention amount of the polymer material between the extruder and the polymer material inlet is measured, and the rotation speed of the extruder screw and / or the polymer material from the kneader to the extruder is measured according to the measurement result. A method for controlling the extrusion rate of a continuous extruder, which comprises controlling the supply rate of 2. A monitor camera for photographing the polymer material is installed at an inlet of the polymer material of the extruder, and an image obtained from the monitor camera is input to an image processing apparatus, and the image processing apparatus is operated. The method for controlling the extrusion amount of a continuous extruder according to claim 1, wherein the retention amount of the polymer material is measured by image processing. 3. A continuous extruder control for connecting a kneading machine and a continuous extruder with a chute tube to control an extrusion rate of a polymer material supplied from the kneading machine to the continuous extruder. In the apparatus, measuring means for measuring the amount of retention of the polymer material between the polymer material outlet of the kneader and the polymer material inlet of the extruder as one of the operation control amounts for controlling the extrusion amount, A controller for a continuous extruder, comprising: a control unit that controls the extrusion amount based on the measured staying amount and another operation control amount. 4. A photographing means installed at the inlet of the polymeric material of the extruder, for photographing the polymeric material, and an image obtained from the photographing means is image-processed to retain the polymeric material. The control device for a continuous extruder according to claim 3, wherein the measuring means has an image processing means for acquiring the.