JPH03230932A - Apparatus for controlling resin temperature of extruder - Google Patents

Abstract

PURPOSE:To carry out extrusion with less dispersion or variation in resin temperature, and improve the quality of articles by controlling the adjustment of resin temperature by the speed of a screw and the temperature of tip of a barrel or the temperature of the screw and the like. CONSTITUTION:At the tip of a barrel 1, a barrel temperature detector 11 for detecting the temperature of tip end part of the barrel 1 is provided, and at the tip end part 2b of a screw 2, a screw temperature detector 12 is provided which serves to detect the temperature of the screw. In cases where the resin temperature data collected is out of the range A of the set dispersion and the range of the average resin temperature B, at first, a signal (controlled variable : Ns) for controlling the speed of the screw is outputted to a screw driving part in order to control the speed of the screw 2. Next, a signal (controlled variable : Br) for controlling the barrel temperature is outputted to a barrel temperature control part so as to control the temperature of the barrel 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a resin temperature control device for an extruder, and is particularly applicable to a twin-screw extruder.

(Prior Art) Resin temperature control using a conventional extruder was performed only by adjusting the barrel temperature at the tip of the extruder.

(Problem to be solved by the invention) As described above, if the resin temperature at the tip of the extruder is adjusted only by the barrel temperature, the response is slow and the adjustment takes time, and the resin temperature varies widely. However, there were some defects that affected the quality of molded products. Furthermore, when PID control is performed, there is a problem in that initial fluctuations are large due to PID overshoot, and it takes time for control to stabilize.

The present invention has been made in view of the above circumstances, and its purpose is to provide a resin temperature control device for an extruder that has little variation in resin temperature, has a quick response, and can quickly respond to fluctuations. be.

(Means for solving the problem) In order to solve the above problem, a rotating screw force of 1
The resin temperature control device for an extruder according to the present invention is provided with a screw rotation speed detection unit that detects the rotation speed of the rotary screw, and a temperature control device that controls the temperature of either or both of the extrusion tip portion of the barrel or the rotary screw. Suppressing variations in resin temperature based on the temperature detection section and the screw rotation speed detected by the screw rotation speed detection section, and either or both of the barrel temperature or the screw temperature detected by the temperature detection section. A configuration including a control section that adjusts the absolute value of the resin temperature based on the temperature of the resin is adopted.

(Function) The rotational speed of the rotary screw detected by the screw rotational speed detection section and either or both of the barrel tip temperature and the screw temperature detected by the temperature detection section are input to the control section.

The control unit controls the resin temperature based on the input screw rotation speed and either or both of the barrel tip temperature and the screw temperature. That is, variations in resin temperature are suppressed based on the screw rotation speed, and the absolute value of the resin temperature is adjusted based on either or both of the barrel tip temperature and the screw temperature. In this way, by controlling the adjustment of the resin temperature using the screw rotation speed, the barrel tip temperature, the screw temperature, etc., each control amount can be adjusted in small amounts, and the response is quick. Furthermore, compared to conventional control methods in which resin temperature is adjusted only by barrel temperature, extrusion can be performed with fewer variations and fluctuations in resin temperature, improving product quality.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic configuration of an extruder according to an embodiment of the present invention.

The extruder of this embodiment is a twin-screw extruder, and two screws 2 (however, only one is shown in the drawing) are housed in a barrel 1. The rear end 2a of the screw 2 is coaxially connected to one gear 3a housed in a reduction gear box 3, and the other gear 3b meshes with this gear 3a.
The rotating shafts 4a of the electric motors 4 are coaxially connected.

On the other hand, a barrel temperature detection section 11 is provided at the tip of the barrel 1 to detect the temperature of the tip of the barrel 1, and the output of this barrel temperature detection section 11 is given to the control section 15. . Specifically, the barrel temperature detection unit 11 detects the temperature of oil flowing in an oil flow passage (not shown) provided inside the barrel 1. Further, a screw temperature detection section 12 is provided at the tip end 2b of the screw 2 to detect the temperature of the screw, and the output of this screw temperature detection section 12 is given to the control section 15.

Specifically, the screw temperature detection unit 12 detects the temperature of oil flowing in an oil flow passage (not shown) provided inside the screw 2. Further, a screw rotation speed detection section 13 that detects the rotation speed of the screw 2 is provided at the rear end portion 2a of the screw 2, and the output of this screw rotation speed detection section 13 is given to the control section 15. ing.

Further, a resin temperature measuring section 14 for measuring resin temperature is provided between the tip of the barrel 1 and the mold 16. This resin temperature measuring section 14 measures the temperature distribution by multi-point measurement, and in this embodiment, multi-point R and rings are used. The control unit 15 controls each of these detection units 11, 12, 13 .
The resin temperature is controlled based on the detection data from 14, and is configured by software running on a microcomputer.

Next, the operation of the resin temperature control device having the above configuration will be described with reference to the flowcharts shown in FIGS. 2 to 4.
(1) When controlling based on the output of the screw rotation speed detection section 13 and the output of the screw temperature detection section 12, (2) When controlling based on the output of the screw rotation speed detection section 13 and the output of the barrel temperature detection section 11 The cases in which the control is performed based on the output of the screw temperature detection section 12 and the output of the screw temperature detection section 12 will be explained separately.

(2) A case where control is performed based on the output of the screen rotation speed detection section 13 and the output of the barrel temperature detection section 11;

First, a permissible variation range A of resin temperature detected by the resin temperature measuring section 14 and an average resin temperature B are set.

For example, the variation range A is set to 10°C, and the average resin temperature B is set to 188±2°C (step 511). Thereafter, the extruder is operated, the resin temperature is measured by the resin temperature measurement section 4, and the measured data is input to the control section 15 in real time (step 512). In the control unit 15,
The actual resin temperature data measured by the resin temperature measurement unit 14 is compared with the variation range A and the average resin temperature B set in step Sll, and the collected resin temperature data is compared with the set variation range A and the average resin temperature data. If the resin temperature is within B, resin temperature control is ended (step 518). On the other hand, if the collected resin temperature data deviates from the set variation range A and average resin temperature B, first send a signal (control amount: N) for controlling the screw rotation speed to the screw drive unit ( (not shown) to control the rotation speed of the screw 2 (step 5).
14). For example, if the collected resin temperature data deviates from the lower side of the set variation range A and average resin temperature B, the rotational speed of the screw 2 is increased by one step to increase the screw rotational speed, and the collected resin temperature data is If the resin temperature data deviates from the upper side of the set variation range A and average resin temperature B, the rotational speed of the screw 2 is lowered to reduce the number of screw rotations. While performing such control, the resin temperature measurement section 14 continues to measure the resin temperature, and the measurement results are input to the control section 15 (step 51).
5). The control unit 15 continuously compares the resin temperature data collected by the resin temperature measuring unit 14 with the set variation range A and average resin temperature B, and the collected resin temperature data is set. If it is within the determined variation range A and average resin temperature B, resin temperature control is ended (steps 316, 318). On the other hand, if the collected resin temperature data deviates from the set variation range A and average resin temperature B, then a signal (control amount 2B) for controlling the barrel temperature is sent to the barrel temperature control section. (not shown) to control the temperature of the barrel 1 (step 517). For example, the variation range A and the average resin temperature B in which the collected resin temperature data are set
If it deviates to the lower side, the control output amount of the barrel heater is increased and the circulation amount of the barrel temperature adjustment oil is decreased to increase the temperature of the oil supplied to the barrel 1 and raise the barrel temperature. In addition, if the collected resin temperature data deviates from the upper side of the set variation range A and average resin temperature B, the control output amount of the barrel heater is decreased and the circulation amount of barrel temperature adjustment oil is increased. , the barrel temperature is lowered by lowering the temperature of the oil supplied to the barrel 1. Thereafter, the process returns to step S12 again, and the control from step 312 to step S17 is repeated until the resin temperature data collected in step S16 falls within the set variation range A and average resin temperature B.

As a result of performing twin-screw extrusion molding with the above control,
The resin temperature at the tip of the barrel is a minimum value of 185°C and a maximum value of 1.
The average resin temperature was 189°C. That is, it was confirmed that by using the resin temperature control device of the present invention, it is possible to control the variation range A and the average resin temperature B within the set values. However, the operating conditions at this time are as follows.

Extruder: 2 shafts rotating in different directions fully intermeshing type Diameter: 90 mm Mold: Pipe diameter: 250 mm Output amount: 500 kg/H Screw rotation speed: 33 rpm Barrel temperature = 175°C Screw lubricating oil temperature: 110°C Resin: Hard PVC On the other hand In order to compare with the above results, the results of resin temperature control using the conventional method described above (control by adjusting only the barrel temperature) are shown below.

In this case, the resin temperature at the tip of the barrel is a minimum value of 187°.
The maximum value of C1 was 206°C, with a variation of 19°C, and the average value of the resin temperature was 191°C. That is, it can be seen that in the conventional resin temperature control, the variation range A and the average resin temperature B are outside the set ranges. However, the operating conditions at this time are as follows.

Extruder: 2-wheel directional rotation fully intermeshing type, diameter 90mm Mold: Vibro diameter 250M Extrusion amount: 500kg/H Screw rotation speed: 36rp City barrel temperature: 170°C Screw temperature control oil temperature: 100°C Resin: Hard PVC (2) When controlling based on the output of the screw rotation speed detection section 13 and the output of the screw temperature detection section 12.

First, the allowable variation range A of the resin temperature detected by the resin temperature measuring section 14 is set to 10°C1, and the average resin temperature B is set to 10°C.
The temperature is set to 88±2°C (step 521).

Thereafter, the extruder is operated, the resin temperature is measured by the resin temperature measurement section 14, and the measured data is input to the control section 15 in real time (step 522).

The control unit 15 compares the actual resin temperature data measured by the resin temperature measurement unit 14 with the variation range A and average resin temperature B set in step S21, and sets the collected resin temperature data. If it is within the variation range A and the average resin temperature B, resin temperature control is ended (step 328). On the other hand, if the collected resin temperature data deviates from the set variation range A and average resin temperature B, first the signal for controlling the screw rotation speed (control 1: NS) is sent to the screw drive unit (not shown). (omitted) to control the rotation speed of the screw 2 (step 524). For example, if the collected resin temperature data deviates from the lower side of the set variation range A and the average resin temperature B, the rotation speed of the screw 2 is increased to increase the screw rotation speed, and the collected resin temperature If the data deviates from the upper side of the set variation range A and average resin temperature B, the rotational speed of the screw 2 is lowered to reduce the number of screw rotations. While performing such control, the resin temperature measurement section 14 continues to measure the resin temperature, and the measurement results are input to the control section 15 (step 525). The control unit 15 continuously compares the resin temperature data collected by the resin temperature measuring unit 14 with the set variation range A and average resin temperature B, and the collected resin temperature data is set. If it is within the determined variation range A and average resin temperature B, the resin temperature control is ended (step 526S28).
). On the other hand, if the collected resin temperature data deviates from the set variation range A and average resin temperature B, the next signal (control amount:
87) to the screw temperature control unit (not shown),
The temperature of the screw 2 is controlled (step 527). For example, if the collected resin temperature data deviates from the lower side of the set variation range A and average resin temperature B, the temperature of the screw 2, that is, the temperature of the oil supplied to the screw 2, is increased to increase the screw temperature. and the collected resin temperature data set variation range A and average normal temperature B.
If the screw 2 is off to the upper side, the temperature of the oil supplied to the screw 2 is lowered to lower the screw temperature. And after,
Returning to step S22 again, step 322 is performed until the resin temperature data collected in step S26 falls within the set variation range A and average resin temperature B.
- Repeat the control in step S27.

As a result of performing twin-screw extrusion molding with the above control,
The resin temperature at the tip of the barrel is a minimum value of 185°C and a maximum value of 1.
The average resin temperature was 189°C. That is, it was confirmed that by using the resin temperature control device of the present invention, it is possible to control the variation range A and the average resin temperature B within the set values. However, the operating conditions at this time are as follows.

Extruder = 2 shafts rotating in different directions fully intermeshing type Diameter 90mm Mold: Vibro diameter 250mm Extrusion rate: 500kg/H Screw rotation speed: 32rpm Barrel temperature = 170°C Screw temperature control oil temperature: 120°C Resin: Hard PVC ■ When controlling based on the output of the screw rotation speed detection section 13, the output of the barrel temperature detection section 11, and the output of the screw temperature detection section 12.

First, the allowable variation range A of the resin temperature detected by the resin temperature measuring section 14 is set to 10°C1, and the average resin temperature B is set to 10°C.
88±2"C (step 531).

Thereafter, the extruder is operated, the resin temperature is measured by the resin temperature measuring section 14, and the measured data is input to the control section 5 in real time (step 532).

The control unit 15 compares the actual resin temperature data measured by the resin temperature measuring unit 14 with the variation range A and average resin temperature B set in step S31, and sets the collected resin temperature data. If it is within the variation range A and the average resin temperature B, resin temperature control is ended (step 538). On the other hand, if the collected resin temperature data deviates from the set variation range A and average resin temperature 5B, first a signal (control amount: NS) for controlling the screw rotation speed is sent to the screw drive unit (
(not shown) to control the rotation speed of the screw 2 (step 534). For example, if the collected resin temperature data deviates from the lower side of the set variation range A and the average resin temperature B, the rotation speed of the screw 2 is increased to increase the screw rotation speed, and the collected resin temperature If the data deviates from the upper side of the set variation range A and average resin temperature B, the rotational speed of the screw 2 is lowered to reduce the number of screw rotations. While performing such control, the resin temperature measurement section 14 continues to measure the resin temperature, and the measurement results are input to the control section 15 (step 535). The control unit 15 continuously compares the resin temperature data collected by the resin temperature measuring unit 14 with the set variation range A and average resin temperature B, and the collected resin temperature data is set. If it is within the determined variation range A and average resin temperature B, resin temperature control is ended (step S36°6 838). On the other hand, if the collected resin temperature data deviates from the set variation range A and average resin temperature B, then a signal (control amount: Bt) for controlling the barrel temperature is sent to the barrel temperature control section ( (not shown) as well as a signal for controlling the screw temperature (control amount:
81) to the screw and J-temperature control section (not shown) to control the temperature of the barrel 1 and the temperature of the screw 2.Step 537). For example, if the collected resin temperature data deviates from the lower side of the set variation range A and average resin temperature B, the control output amount of the barrel heater is increased and the circulation amount of barrel temperature adjustment oil is decreased. ,
The barrel temperature is increased by increasing the temperature of the oil supplied to the barrel 1, and the temperature of the screw 2, that is, the screw 2 is increased.
Increase the temperature of the oil supplied to the screw to raise the screw temperature. In addition, if the collected resin temperature data deviates from the upper side of the set variation range A and average resin temperature B, the control output amount of the barrel heater is decreased and the circulation amount of barrel temperature adjustment oil is increased. , lowering the temperature of the oil supplied to the barrel 1 to lower the barrel temperature,
The temperature of the oil supplied to the screw 2 is lowered to lower the screw temperature. The adjustment ratio between the barrel temperature and the screw temperature at this time may be arbitrary. For example, you can adjust both temperatures in equal proportions (or adjust the barrel temperature many times,
Adjustment of the screw temperature may be made less, or conversely, adjustment of the barrel temperature may be made less and adjustment of the screw temperature may be made more. Thereafter, the process returns to step S32 again, and the control from step 332 to step S37 is repeated until the resin temperature data collected in step 336 falls within the set variation range A and average resin temperature B.

As a result of performing twin-screw extrusion molding with the above control,
The resin temperature at the tip of the barrel is a minimum value of 185°C and a maximum value of 1.
The average resin temperature was 189°C. That is, it was confirmed that by using the resin temperature control device of the present invention, it is possible to control the variation range A and the average resin temperature B within the set values. However, the operating conditions at this time are as follows.

Extruder = 2 shafts rotating in different directions, fully intermeshing type, diameter 90 mm Mold: Vibro diameter 250 stones Extrusion amount: 500 kg/l (Screw rotation speed: 33 rpm Barrel temperature: 175°C Screw temperature control oil temperature: 110°C Resin: Hard PVC (Effects of the Invention) The resin temperature control device for an extruder according to the present invention detects either the rotation speed of the rotary screw detected by the screw rotation speed detection means, or the barrel tip temperature or the screw temperature detected by the temperature detection means. Since the resin temperature is controlled based on one or both temperatures, it is possible to extrude with less variation and variation in resin temperature compared to the conventional control method that adjusts resin temperature only by barrel temperature. , product quality can be improved.Furthermore, each control amount can be adjusted in small amounts, and the response can be quickened, resulting in the following effects.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a resin temperature control device for an extruder according to the present invention, and FIGS. 2 to 4 are flowcharts for explaining the operation of the device. ■ Barrel 2 Screw 11 Barrel temperature detection section 12 Screw temperature detection section 13 Screw rotation speed detection section 14 Resin temperature measurement section 15 Control Department

Claims (1)

[Scope of Claims] 1) An extruder having a rotating screw provided in a barrel, comprising: a screw rotation speed detection unit that detects the rotation speed of the rotating screw; and either an extrusion tip portion of the barrel or the rotating screw. a temperature detection section that detects one or both temperatures; and suppressing variations in resin temperature based on the screw rotation speed detected by the screw rotation speed detection section;
and a control section that adjusts the absolute value of the resin temperature based on either or both of the barrel temperature and the screw temperature detected by the temperature detection section. .