JP2001096605A - Serial two-stage extruder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a serial two-stage extruder which can control discharge precisely and constantly. SOLUTION: In an apparatus which controls the number of revolution of the first stage extruder 10 to make the discharge accurate and constant by a method in which the extruder 10 is connected with the second stage extruder 20, a resin temperature in the screw groove of the extruder 20 is kept constant while the revolution of and a cylinder temperature of the extruder 20 are kept constant, a pressure difference between the inlet and outlet of the extruder 20 is kept constant, when a resin temperature in the extruder 20 is different from a target resin temperature, on the basis of the temperature difference and the physical property data of the resin, the viscosity of the resin flowing in the screw groove of the extruder 20 and the pressure difference between the inlet and outlet of the extruder 20 during target discharge are estimated, and a target pressure difference is changed, in the extruder 10, the screw revolution of the extruder 10 is controlled so that the pressure of the outlet of the extruder 10 or the pressure of the inlet of the extruder 20 is a target pressure, and the target pressure is changed on the basis of the difference between the pressure difference between the inlet and outlet of the extruder 20 and the target pressure difference to reduce the variation of the discharge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant control of a discharge amount of a two-stage in-line extruder (hereinafter, referred to as a tandem extruder).

[0002]

2. Description of the Related Art FIG. 7 is a view showing the entire configuration of a tandem extruder according to a first conventional example. The tandem extruder shown in FIG. 7 includes a first-stage extruder 10 for plasticizing a resin, and a second-stage extruder for homogenizing, measuring, and increasing the pressure of the resin plasticized by the first-stage extruder 10. 20 and a connecting pipe 30 connecting the first-stage extruder 10 and the second-stage extruder 20.

[0003] As a conventional example relating to constant control of the discharge amount of a tandem extruder, as shown in FIG.
0 while keeping the number of rotations of the drive motor 241 constant.
Connecting pipe 3 for connecting stage extruder 10 and second stage extruder 20
0 or a pressure detector 271 is installed in the resin inflow section 20A of the second-stage extruder 20, and the first-stage extruder 20 is rotated via the rotation speed controller 15 so that the pressure detected here becomes a preset pressure. There is a method of controlling the number of rotations of the drive motor 141 of the extruder 10.

FIG. 8 is a diagram showing the overall configuration of a tandem extruder according to a second conventional example. The tandem extruder shown in FIG. 8 includes a connecting pipe 30 for connecting the first-stage extruder 10 and the second-stage extruder 20 or a resin inflow portion 20 of the second-stage extruder 20.
A, a pressure detector 271 is installed, and the rotation speed controller 15 is adjusted so that the pressure detected here becomes a preset pressure.
Controls the number of rotations of the drive motor 141 of the first-stage extruder 10 through the controller, detects the pressure 511 immediately before the inflow of the die 50, and controls the second-stage extruder 20 so that the pressure becomes constant. The number of rotations of the drive motor 241 is controlled.

FIG. 9 is a view showing the overall configuration of a tandem extruder according to a third conventional example. JP-A-02-16052
No. 8, as shown in FIG. 9, while maintaining the rotation speed of the second-stage extruder 20 constant, detects the pressure 412 immediately before the inflow of the outlet of the filter 40 or the die 50, and this pressure becomes constant. Thus, a method for controlling the number of rotations of the drive motor 141 of the first-stage extruder 10 has been proposed.

[0006]

In any of the first to third prior arts described above, the method of controlling the driving motor of the extruder by detecting only the pressure does not involve melting of the plasticized resin due to a change in the temperature of the plasticized resin. It responded to pressure changes due to changes in resin viscosity, pressure changes due to clogging of the filter and flow path resistance due to adjustment of the die lip opening, and it was not possible to improve the accuracy of keeping the discharge rate constant.

An object of the present invention is to provide a two-stage in-line extruder capable of controlling the discharge amount with high accuracy.

[0008]

Means for Solving the Problems In order to solve the above problems and achieve the object, the in-line two-stage extruder of the present invention is constituted as follows.

(1) The in-line two-stage extruder of the present invention
The second-stage extruder and the second-stage extruder are connected, and while keeping the screw rotation speed and the cylinder temperature of the second-stage extruder constant, the resin temperature in the screw groove of the second-stage extruder is kept constant,
When the pressure difference between the inlet and the outlet of the second-stage extruder is kept constant, and the detected resin temperature in the second-stage extruder is different from the target resin temperature, the difference between the temperature difference and the previously measured resin Based on the physical property data, the viscosity of the resin flowing in the screw groove of the second-stage extruder and the pressure difference between the inlet and the outlet of the second-stage extruder at the time of the target discharge amount are estimated, and the target pressure difference is changed. By controlling the number of revolutions of the first-stage extruder, it is a series two-stage extruder that makes the discharge amount constant with high accuracy, and the first-stage extruder is a The screw speed of the first-stage extruder is controlled such that the pressure at the outlet or the inlet of the second-stage extruder becomes the target pressure, and the target pressure is adjusted between the inlet and the outlet of the second-stage extruder. Change based on the difference between the pressure difference and its target pressure difference, Reduction to.

(2) The in-line two-stage extruder of the present invention
The stage extruder and the second stage extruder are connected by a conduit, and while keeping the temperature of the pressure loss measurement section of the conduit constant, the resin temperature of the pressure loss measurement section is constant, and the inlet of the pressure loss measurement section is When the pressure difference at the outlet is kept constant and the detected resin temperature in the pressure loss measurement section is different from the target resin temperature, the pressure loss measurement is performed based on the temperature difference and physical property data of the resin measured in advance. Estimating the pressure difference between the inlet and the outlet of the pressure loss measurement section at the time of the target viscosity and the viscosity of the resin flowing through the section, and controlling the rotation speed of the first-stage extruder by changing the target pressure difference A two-stage in-line extruder for making the discharge rate constant with high precision, wherein the first-stage extruder is provided at the outlet of the first-stage extruder, at the entrance of the pressure-loss measurement section, or at the pressure-loss measurement section. Outlet pressure is target pressure Controlling the screw rotation speed of the first stage extruder, and changing the target pressure based on the difference between the pressure difference between the inlet and the outlet of the pressure loss measurement section and the target pressure difference, Reduce the fluctuation of the discharge amount.

(3) The in-line two-stage extruder of the present invention
The second-stage extruder is connected to the second-stage extruder, and the resin temperature in the screw groove of the second-stage extruder is kept constant while the screw rotation speed of the second-stage extruder is kept constant. While keeping the pressure difference between the inlet and the outlet of the extruder constant, and when the detected resin temperature in the second-stage extruder is different from the target resin temperature, based on the temperature difference and the previously measured physical property data of the resin, By estimating the viscosity of the resin flowing in the screw groove of the second-stage extruder and the pressure difference between the inlet and the outlet of the second-stage extruder at the time of the target discharge amount, and changing the target pressure difference, Controlling the number of revolutions of the first stage extruder,
It is a series two-stage extruder that changes the cylinder temperature so that the outlet temperature of the second-stage extruder becomes constant, and makes the discharge amount and the discharge resin temperature constant with high accuracy. Controlling the screw rotation speed of the first-stage extruder so that the pressure at the outlet of the first-stage extruder or the pressure at the inlet of the second-stage extruder becomes the target pressure, and adjusting the target pressure to the second pressure. The change is made based on the difference between the pressure difference between the inlet and the outlet of the step extruder and the target pressure difference, thereby reducing the fluctuation of the discharge amount.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 shows a tandem extruder (series 2) according to a first embodiment of the present invention.
FIG. 2 is an overall configuration diagram of a control system of a stage extrusion device and a serial two-stage extrusion molding device), and FIG. 2 is a system diagram of the control system. 1 and 2, the same parts as those in FIGS. 7 to 9 are denoted by the same reference numerals. Also, the feedback amount is given a positive or negative sign.

In the first embodiment, the second-stage extruder 2
While maintaining the rotation speed of 0 and the cylinder temperature of the second-stage extruder 20 constant, the pressure detector 271 is connected to the inlet of the second-stage extruder 20.
The pressure detector 272 is installed at the outlet of the second stage extruder 20 to detect the pressure. The rotation speed of the first-stage extruder 10 is determined by the pressure detected by the pressure detector 172 installed at the outlet of the first-stage extruder 10.
Drive motor 14 of the first stage extruder 10 through the rotation speed controller 151 so that the target pressure is set to 0.
It is determined by controlling the number of rotations of one. The pressure detector 1
72 may be shared with the pressure detector 171.

At the inlet of the second-stage extruder 20 and at the outlet of the second-stage extruder 20, resin temperature detectors 281 and 282 for the molten resin flowing through the conduit 30 are installed, respectively. Detect the temperature of The operation amount calculator 162 and the cylinder of the first stage extruder 10 are controlled so that the temperature detected by the temperature detector 281 at the entrance of the second stage extruder 20 becomes the target resin temperature set by the target temperature setter 161. The temperature of the cylinder 11 of the first-stage extruder 10 is changed through the temperature controller 163.

The target pressure setter 60 sets the pressure difference based on the difference between the pressure difference detected between the two pressure detectors 271 and 272 and the target pressure difference set by the target pressure difference setter 70. Change the target pressure. In addition,
When the resin temperature (one of the values or the average value) detected by the resin temperature detectors 281 and 282 changes, the target pressure difference set by the target pressure difference setting device 70 is changed based on the change amount. This circuit need not be used if a slight decrease in accuracy is allowed.

It is assumed that the tandem extruder is operated at a target pressure and a target resin temperature. Here, it is assumed that there is disturbance (here, for example, filter clogging) that changes the discharge amount such as clogging of the filter 40 and temperature change of the input material. In this case, since the resistance of the conduit 30 increases due to clogging of the filter, the discharge amount decreases, and the resin temperature tends to increase. At this time, based on the difference between the temperature of the molten resin flowing through the conduit 30 at the inlet of the second-stage extruder 20 and the target resin temperature, the cylinder temperature of the first-stage extruder 10 is set so that the difference becomes zero. , The rise of the resin temperature is prevented. Furthermore, the respective pressures at the inlet of the second-stage extruder 20 and the outlet of the second-stage extruder 20 are detected, and based on the difference between the pressure difference and the target pressure difference, the difference becomes zero. In order to increase the rotation speed of the drive motor 141 of the first-stage extruder 10, the target pressure of the pressure 172 at the outlet of the first-stage extruder 10 is reset to a high value.

When the resin temperature (one of the values or the average value) detected by the temperature detectors 281 and 282 changes, the amount of the rise in the temperature is determined based on the previously measured physical property data of the resin. Is estimated, the pressure difference between the inlet and the outlet of the second stage extruder 20 at which the target discharge rate is achieved at the expected viscosity is estimated, and the target pressure difference is changed (increased) to the pressure difference. Then, the target pressure of the first stage extruder 10 is changed accordingly. In this manner, the first-stage extruder 10 increases the rotation speed of the screw 12 to maintain the target pressure, and prevents a decrease in the discharge amount.

As described above, while the screw speed and the cylinder temperature of the second stage extruder 20 are kept constant, the resin temperature at the inlet of the second stage extruder 20 is kept constant, and the inlet and outlet of the second stage extruder 20 are kept constant. Is constant, and even if the resin temperature in the second stage extruder 20 fluctuates, the rotation speed of the first stage extruder 10 is controlled by changing to a target pressure difference corresponding to the resin temperature. As a result, even with a large disturbance, the discharge amount can be controlled with high accuracy.

(Second Embodiment) FIG. 3 is an overall configuration diagram of a control system for a tandem extruder according to a second embodiment of the present invention, and FIG. 4 is a system diagram of the control system. 3 and 4, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals. Also, the feedback amount is given a positive or negative sign.

In the second embodiment, a pressure loss setting means 300 with a temperature controller is provided in the conduit 30. While keeping the temperature of the conduit 30 constant, a pressure detector 311 is provided upstream of the pressure loss setting means (pressure loss measuring section) 300.
A pressure detector 312 is installed downstream to detect those pressures. The rotation speed of the first-stage extruder 10 is
0 through the rotation speed controller 152 so that the pressure detected by the pressure detector 172 installed at the outlet of the zero pressure becomes the target pressure set by the target pressure setter 60.
The number of rotations of the drive motor 141 of the step extruder 10 is controlled and determined. Note that the pressure detector 172 is
1 may be shared.

Further, resin temperature detectors 321 and 322 for the molten resin flowing in the conduit 30 are installed upstream and downstream of the pressure loss setting means 300, respectively, and the temperature of the molten resin is detected by them. The temperature detected by the temperature detector 321 at the entrance of the second stage extruder 20 is the target temperature setting unit 16.
1 through the deviation amount calculator 162 and the cylinder temperature adjustment operation amount calculator 163 ′ of the first stage extruder 10 so as to reach the target resin temperature set by 1. The temperature of the cylinder 11 is changed by controlling the heater 13.

The target pressure setting unit 60 sets the pressure difference based on the difference between the pressure difference detected between the two pressure detectors 311 and 312 and the target pressure difference set by the target pressure difference setting unit 70. Change the target pressure. In addition,
When the resin temperature (one of the values or the average value) detected by the resin temperature detectors 321 and 322 changes, the target pressure difference set by the target pressure difference setting device 70 is changed based on the amount of change. This circuit need not be used if a slight decrease in accuracy is allowed.

The pressure loss setting means 300 may be a resistance value obtained by evaluating the resistance of the conduit 30 as it is, or a throttle having a smaller sectional area than the conduit 30 as shown in FIG. Further, a resistor such as a mesh may be used.

It is assumed that the present tandem extruder is operated at a target pressure and a target resin temperature. Here, it is assumed that there is disturbance (here, for example, filter clogging) that changes the discharge amount such as clogging of the filter 40 and temperature change of the input material. In this case, since the resistance of the conduit 30 due to clogging of the filter increases, the discharge amount decreases, and the resin temperature tends to increase. At this time, the temperature of the molten resin flowing in the conduit 30 is measured on the upstream side of the pressure loss setting means 300, and based on the difference between the temperature and the target resin temperature, the first-stage extrusion is performed so that the difference becomes zero. By lowering the cylinder temperature of the machine 10, an increase in the resin temperature is prevented. Further, the first stage extruder 10 detects the respective pressures on the upstream side and the downstream side of the pressure loss setting means 300 and sets the first stage extruder 10 so that the difference becomes zero based on the difference between the pressure difference and the target pressure difference. In order to increase the number of rotations of the drive motor 141, the target pressure of the outlet pressure of the first-stage extruder 10 is reset to a high value.

However, the wall surface of the pressure loss setting means 300 is always kept at a constant temperature. In addition, the temperature detector 3
When the resin temperature (one value or the average value) detected by 21 and 322 changes, a viscosity decrease corresponding to the temperature rise is estimated based on the resin physical property data measured in advance, The pressure difference between the upstream side and the downstream side of the pressure loss setting means 300 at which the target discharge amount is achieved at the predicted viscosity is estimated, and the above-mentioned target pressure difference is changed (increased) to the value, and The target pressure of the single-stage extruder 10 is changed. In this manner, the first-stage extruder 10 increases the rotation speed of the screw 12 to maintain the target pressure, and prevents a decrease in the discharge amount.

As described above, the resin temperature at the inlet of the pressure loss setting means 300 is kept constant while the conduit temperature of the pressure loss setting means 300 is kept constant.
Controlling the rotation speed of the first-stage extruder 10 by keeping the pressure difference at the outlet constant and changing the target pressure difference corresponding to the resin temperature even if the resin temperature of the pressure loss setting means 300 fluctuates. Thus, even for a large disturbance, it is possible to perform a highly accurate control of stabilizing the ejection amount.

(Third Embodiment) FIG. 5 is an overall configuration diagram of a control system of a tandem extruder according to a third embodiment of the present invention, and FIG. 6 is a control system diagram thereof. 5 and 6, the same parts as those in FIGS. 3 and 4 are denoted by the same reference numerals. Also, the feedback amount is given a positive or negative sign.

In the third embodiment, the second-stage extruder 2
The pressure detector 271 is installed at the inlet of the second-stage extruder 20 and the pressure detector 272 is installed at the outlet of the second-stage extruder 20 while keeping the number of rotations of 0 constant. The rotation speed of the first-stage extruder 10 is set such that the pressure detected by the pressure detector 172 installed at the outlet of the first-stage extruder 10 becomes the target pressure set by the target pressure setter 60. The rotation speed of the drive motor 141 of the first-stage extruder 10 is controlled through the rotation speed controller 153 and is determined. Note that the pressure detector 272 may be shared with the pressure detector 271.

Also, at the inlet and outlet of the second stage extruder 20,
Temperature detectors 281 and 282 for the molten resin flowing in the conduit 30 are installed, and the temperatures of the molten resin are detected. Temperature detector 281 at the entrance of the second stage extruder 20
The temperature deviation calculator 16 is set so that the temperature detected in the step (b) becomes the target resin temperature set by the target temperature setter 161.
2. The amount of heat of the cylinder temperature adjusting heater (heater) 13 of the first stage extruder 10 is changed through the manipulated variable calculator 163 for the cylinder temperature controller of the first stage extruder 10.

The target pressure setter 60 sets the pressure difference based on the difference between the pressure difference detected between the two pressure detectors 271 and 272 and the target pressure difference set by the target pressure difference setter 70. Change the target pressure. In addition,
When the resin temperature (one of the values or the average value) detected by the resin temperature detectors 281 and 282 changes, the target pressure difference set by the target pressure difference setting device 70 is changed based on the amount of change. If a slight decrease in accuracy can be tolerated, this circuit need not be used.

Further, the temperature of the second-stage cylinder 21 is adjusted so that the resin temperature detected by the resin temperature detector 282 becomes the target extruded resin temperature set by the target temperature setting device 261.

It is assumed that the tandem extruder is operated at a target pressure and a target resin temperature. Here, it is assumed that there is disturbance (here, for example, filter clogging) that changes the discharge amount such as clogging of the filter 40 and temperature change of the input material. In this case, since the resistance of the conduit 30 due to clogging of the filter increases, the discharge amount decreases, and the resin temperature tends to increase. At this time, based on the difference between the temperature of the molten resin flowing through the conduit 30 at the inlet of the second-stage extruder 20 and the target resin temperature, the cylinder temperature of the first-stage extruder 10 is adjusted so that the difference becomes zero. By lowering, the rise of the resin temperature is prevented. Further, each pressure at the inlet and the outlet of the second stage extruder 20 is detected, and based on the difference between the pressure difference and the target pressure difference, the first stage extruder 10 is controlled so that the difference becomes zero. In order to increase the rotation speed of the drive motor 141, the target pressure of the pressure 172 at the outlet of the first stage extruder 10 is reset to a high value.

When the resin temperature (one of the values or the average value) detected by the temperature detectors 281 and 282 changes, the amount of the rise in temperature is determined based on the previously measured physical property data of the resin. Is estimated, the pressure difference between the inlet and outlet of the second stage extruder 20 at which the target discharge amount is achieved at the predicted viscosity is estimated, and the target pressure difference is changed (increased) to the pressure difference. Then, the target pressure of the first stage extruder 10 is changed accordingly. In addition, the second-stage extruder 2
The cylinder temperature of the second-stage extruder 20 is controlled so that the difference between the resin temperature at the outlet of 0 and the target extruded resin temperature becomes 0. Thus, the first-stage extruder 10 increases the rotation speed of the screw 12 to maintain the target pressure, thereby preventing a decrease in the discharge amount and discharging the molten resin at a constant temperature from the second-stage extruder 20. can do.

As described above, while keeping the screw rotation speed of the second-stage extruder 20 constant, the resin temperature at the inlet of the second-stage extruder 20 is kept constant, and the pressure difference between the inlet and the outlet of the second-stage extruder 20 is maintained. Is constant, and even if the resin temperature in the second-stage extruder 20 fluctuates, the rotation speed of the first-stage extruder 10 is controlled by changing to a target pressure difference corresponding to the resin temperature,
By changing the cylinder temperature of the second-stage extruder 20 so that the resin temperature of the second-stage extruder 20 is kept constant, the discharge amount and the discharged resin temperature can be controlled with high accuracy even for a large disturbance. Becomes possible.

It should be noted that the present invention is not limited to the above-described embodiments, and can be carried out with appropriate modifications without departing from the scope of the invention.

[0036]

According to the in-line two-stage extruder of the present invention, the screw temperature and the cylinder temperature of the second-stage extruder are kept constant while the resin temperature in the screw groove of the second-stage extruder is kept constant. The pressure difference between the inlet and the outlet of the second-stage extruder is kept constant, and even if the resin temperature in the second-stage extruder 20 fluctuates, it is changed to a target pressure difference corresponding to the resin temperature. By controlling the number of revolutions of the first-stage extruder, it is possible to control the discharge amount with high accuracy even for a large disturbance.

According to the in-line two-stage extruder of the present invention, the resin temperature in the pressure loss measurement section is kept constant while the pipe temperature in the pressure loss measurement section is kept constant, and the inlet and outlet of the pressure loss measurement section are kept constant. While keeping the pressure difference constant, even if the resin temperature in the pressure loss measurement section fluctuates, by changing to a target pressure difference corresponding to the resin temperature and controlling the rotation speed of the first-stage extruder, a large It is also possible to perform highly accurate control of the ejection amount with respect to disturbance.

According to the in-line two-stage extruder of the present invention,
While keeping the screw rotation speed of the step extruder constant, the second
The resin temperature in the screw groove of the second-stage extruder is kept constant, the pressure difference between the inlet and the outlet of the second-stage extruder is kept constant, and even if the resin temperature in the second-stage extruder fluctuates, the resin temperature To control the number of revolutions of the first-stage extruder, and change the cylinder temperature of the second-stage extruder so that the resin temperature of the second-stage extruder becomes constant. By doing so, it is possible to perform highly accurate constant control of the discharge amount and the discharge resin temperature even for a large disturbance.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a control system of a tandem extruder according to a first embodiment of the present invention.

FIG. 2 is a control system diagram according to the first embodiment of the present invention.

FIG. 3 is an overall configuration diagram of a control system of a tandem extruder according to a second embodiment of the present invention.

FIG. 4 is a control system diagram according to a second embodiment of the present invention.

FIG. 5 is an overall configuration diagram of a control system of a tandem extruder according to a third embodiment of the present invention.

FIG. 6 is an overall configuration diagram of a control system of a tandem extruder according to a third embodiment of the present invention.

FIG. 7 is a diagram showing an overall configuration of a tandem extruder according to a first conventional example.

FIG. 8 is a diagram showing the overall configuration of a tandem extruder according to a second conventional example.

FIG. 9 is a diagram showing the overall configuration of a tandem extruder according to a third conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... 1st stage extruder 11 ... Cylinder 12 ... Screw 13 ... Heater (heater) 14 ... Drive 141 ... Motor 142 ... Reduction gear 15 ... Rotation speed adjuster (deviation amount calculator) 151 ... Rotation speed adjuster 1511 ... deviation amount calculator 1512 ... control amount calculation force unit 152 ... rotation amount regulator 1521 ... deviation amount calculation unit 1522 ... control amount calculation force unit 153 ... rotation speed adjustment unit 1531 ... deviation amount calculation unit 1532 ... control amount calculation force unit DESCRIPTION OF SYMBOLS 16 ... Cylinder temperature control device 161 ... Target temperature setter 162 ... Manipulated variable calculator (deviation calculator) 171 ... Pressure detector 172 ... Pressure detector 20 ... Second stage extruder 21 ... Cylinder 22 ... Screw 23 ... Heating device (Heater) 24 Drive unit 241 Motor 242 Speed reducer 26 Target temperature setter 261 Target temperature setter 262 Deviation calculator 263 Control Quantity calculating device 27: molten resin pressure detector 271: molten resin pressure detector at second stage inlet 272 ... molten resin pressure detector at second stage outlet 28 ... molten resin temperature detector 281 ... molten resin at second stage inlet Temperature detector 282: Molten resin temperature detector at the second stage outlet 30: Connecting pipe 40: Filter 50: Die 60: Target pressure setter 70: Target differential pressure setter 80: Differential pressure calculator 90: Pressure of resin viscosity Compensation calculator 91: Resin temperature weighting calculator 92: Resin viscosity to pressure compensation calculator 100: Deviation calculator 110: Deviation calculator 200: First-stage filter 300: Pressure loss setting means (pressure loss measurement section) 310 ... pressure detector 311 ... inlet pressure detector 212 ... outlet pressure detector 320 ... pressure detector 321 ... inlet resin temperature detector 322 ... outlet resin temperature detector

Claims (3)

[Claims] 1. A first stage extruder and a second stage extruder are connected,
While keeping the screw rotation speed and the cylinder temperature of the second-stage extruder constant, the resin temperature in the screw groove of the second-stage extruder is kept constant, and the pressure difference between the inlet and outlet of the second-stage extruder is reduced. When the detected resin temperature in the second-stage extruder is different from the target resin temperature, the screw of the second-stage extruder is fixed based on the temperature difference and the previously measured physical property data of the resin. By estimating the viscosity of the resin flowing in the groove and the pressure difference between the inlet and the outlet of the second-stage extruder at the time of the target discharge amount, and changing the target pressure difference, the rotation speed of the first-stage extruder is reduced. It is a serial two-stage extruder that controls and precisely discharges a constant amount. The first-stage extruder has a target pressure at an outlet of the first-stage extruder or an inlet of the second-stage extruder. So that the pressure
While controlling the screw rotation speed of the first-stage extruder, the target pressure is changed based on the difference between the pressure difference between the inlet and the outlet of the second-stage extruder and the target pressure difference, thereby changing the discharge amount. In-line two-stage extruder, characterized in that the number of extruders is reduced. 2. A first stage extruder and a second stage extruder are connected by a conduit, and the temperature of the pressure loss measurement section of the conduit is kept constant while the resin temperature of the pressure loss measurement section is kept constant. When the pressure difference between the inlet and the outlet of the pressure loss measurement section is constant and the detected resin temperature of the pressure loss measurement section is different from the target resin temperature, the temperature difference and the physical property data of the resin measured in advance are used. Estimating the pressure difference between the inlet and the outlet of the pressure loss measurement section at the time of the target discharge amount based on the viscosity of the resin flowing through the pressure loss measurement section and changing the target pressure difference, An in-line two-stage extruder that controls the number of revolutions of the extruder to make the discharge rate constant with high accuracy, wherein the first-stage extruder is an outlet of the first-stage extruder or an inlet of the pressure-loss measurement section. Or the pressure drop measurement section While controlling the screw rotation speed of the first-stage extruder so that the pressure of the mouth becomes the target pressure, the target pressure is
An in-line two-stage extruder that changes based on a difference between a pressure difference between an inlet and an outlet of the pressure loss measurement section and a target pressure difference between the pressure loss measurement sections to reduce fluctuations in a discharge amount. 3. A first stage extruder and a second stage extruder are connected,
While keeping the screw speed of the second stage extruder constant,
The resin temperature in the screw groove of the second-stage extruder is kept constant, the pressure difference between the inlet and the outlet of the second-stage extruder is kept constant, and the detected resin temperature in the second-stage extruder is set to a target value. When the temperature is different from the resin temperature, the viscosity of the resin flowing in the screw groove of the second-stage extruder and the second-stage extrusion at a target discharge amount are determined based on the temperature difference and the physical property data of the resin measured in advance. Estimate the pressure difference between the inlet and outlet of the machine,
By changing the target pressure difference, the rotation speed of the first-stage extruder is controlled, and the cylinder temperature is changed so that the outlet temperature of the second-stage extruder becomes constant. It is a series two-stage extruder that makes the temperature constant with high precision, and the first-stage extruder is configured such that the pressure at the outlet of the first-stage extruder or the pressure at the inlet of the second-stage extruder becomes a target pressure. Controlling the screw rotation speed of the first-stage extruder, and changing the target pressure based on the difference between the pressure difference between the inlet and the outlet of the second-stage extruder and the target pressure difference. An in-line two-stage extrusion device characterized by reducing fluctuations.