JPH0550425A - Apparatus for controlling degree of kneading in continuous kneading machine - Google Patents

Abstract

PURPOSE:To make it possible to measure the pressure at approximately melting starting point of a resin material by providing a pressure sensor of a control mechanism around the turning point from a feeding blade to a returning blade of a kneading blade part. CONSTITUTION:When a resin material is entered in a kneading blade part, shearing forces from a rotor 5 and a camber 6 are applied thereon. This shearing force successively becomes larger from the apex of a feeding blade A and the max. at a turning point C and decreases with approaching the rear end of the returning blade B. A control mechanism 12 measures the max. resin pressure by means of a pressure sensor 9 provided around this turning point C and to operates comparatively at an operating part 13 whether the max. shearing stress required for obtaining the necessary quality of the resin material is generated. Then, when it is not generated, the number of rotation of the rotor 5 is changed by controlling a variable motor 10 of the rotor 5 and/or the distance of a gap 7 is adjusted by driving a driving apparatus 11 of a movable dam 8 to change it at least to the max. resin pressure generating the required max. shearing stress.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a kneading degree control device for a continuous kneading machine in which a plastic material such as plastic or rubber is continuously plasticized and melted to knead additives, fillers and the like.

[0002]

2. Description of the Related Art A conventional technique of this type is disclosed in Japanese Patent Laid-Open No. 2-263609. As shown in FIG. 5, this technique includes a chamber 6 having a supply port 16 and a discharge port 17 and two chambers having a kneading blade part 3 arranged in parallel in the chamber 6 and driven by a variable motor 10. Rotor 5, supply port 16 and discharge port 1 of chamber 6
7, a movable dam 8 provided so as to be able to adjust the far and near position with respect to the rotor 5, and a gear pump 18 arranged downstream of the discharge port 17.

The movable dam 8 faces a circular section 19 formed on the downstream side of the kneading blade portion 3 of the rotor 5 and forms a gap 7 between the movable dam 8 and the rotor 5, thus forming a drive unit (motor). The gap 7 can be adjusted by driving 11. The rotor 5 is provided with the feed blade portion 4 on the downstream side of the circular section 19 so that the kneaded material can be forcibly pushed to the gear pump 18.

The movable dam 8 has a pressure sensor 20 and a temperature sensor 21 for measuring the pressure and temperature of the resin passing through the gap 7, and the drive unit 11 is based on the measured values obtained from these. Is configured to control. Also,
A pressure sensor 22 is provided at the inlet of the gear pump 18, measures the inlet pressure, and measures the motor 23 of the gear pump 18.
Is controlled to adjust the supply amount of the kneading material to the post-treatment device.

[0005]

In the above prior art, the kneading degree control is performed by measuring the resin pressure or temperature at the movable dam 8 and the inlet of the gear pump 18.
These parts are the parts where the substantial kneading is completed, and they are useful for macroscopic kneading degree control, but it is difficult to expect an effect for microscopic kneading quality control.

That is, the kneading quality such as the dispersibility of the additive and the homogenizing of the resin is determined by the melting start point where the largest shearing force is applied to the resin, and the downstream side away from the melting start point. Even if the kneading degree is controlled by measuring the pressure and the like with, it is difficult to obtain the pressure for obtaining the required quality and there is a time lag, so that more strict control is difficult. By the way, the homogenizing method to erase the fish eye is
The maximum shear stress above the entanglement force is required to loosen the entanglement of the molecules, and when dispersing the aggregates of additives, the maximum shear stress above the cohesive force is required. The shear stress acts near the melting start point, and in the continuous kneader such as the above-mentioned conventional technique, it is usually before and after the turning point C, more specifically, one-third of the feeding blade A to three of the returning blade B. The range is up to one-third.

The maximum shear stress τmax varies depending on the viscosity of the resin, the type of additives, etc., and the maximum resin pressure Pmax / ma for obtaining the maximum shear stress τmax.
It can be calculated from x (maximum axial pressure within the maximum pressure Pmax in the circumferential direction). That is, Pmax / ma
There is a relationship of x = C (constant) · τmax. Therefore, the maximum shear stress τmax required to satisfy the required quality is
It can be obtained by controlling the movable dam 8 so that the maximum resin pressure Pmax / max becomes a required value near the melting start point.

The kneading quality depends on the maximum shear stress τ at one point.
Although max is a decisive factor, it may be influenced by the total maximum shear stress τmax, and it is also effective to control the total maximum shear stress τmax to a required value. The first object of the present invention is to provide a maximum resin pressure Pm in the vicinity of a turning point C between the feeding blade A and the returning blade B of the kneading blade portion 3.
By measuring ax / max with the pressure sensor 9 and controlling at least one of the variable motor 10 of the rotor 5 and the drive device 11 of the movable dam 8, more precise and quick control of the kneading quality can be achieved. Another object of the present invention is to provide a kneading degree control device for the continuous kneading machine.

A second object of the present invention is to use a plurality of pressure sensors 9 to determine the maximum pressure Pmax within a certain range D and E before and after the turning point C between the feeding blade A and the returning blade B of the kneading blade portion 3. The kneading quality is measured by measuring and totaling the plurality of pressure measurement values by the calculation unit 14 to control at least one of the variable motor 10 of the rotor 5 and the drive device 11 of the movable dam 8. An object of the present invention is to provide a kneading degree control device for a continuous kneading machine, which enables more rigorous and quick control.

[0010]

The first concrete means for solving the problems in the present invention is the kneading blade portion 3 and the feeding blade portion 4.
Two rotors 5 each having a rotor are arranged in a chamber 6, and a movable dam 8 for adjusting a gap 7 between the kneading blade portion 3 and the feeding blade portion 4 with the rotor 5 is provided in the chamber 6, and a resin pressure is applied. In the kneading degree control device of the continuous kneading machine, which is provided with a control mechanism 12 for controlling at least one of the variable motor 10 of the rotor 5 and the drive device 11 of the movable dam 8 by measuring the pressure sensor 9 The pressure sensor 9 of 12 is provided in the vicinity of the turning point C between the feeding blade A and the returning blade B of the kneading blade portion 3.

A second specific means for solving the problem in the present invention is to arrange two rotors 5 having a kneading blade portion 3 and a feeding blade portion 4 in a chamber 6, and to the chamber 6, kneading blades. A movable dam 8 for adjusting a gap 7 with the rotor 5 is provided between the portion 3 and the feed blade portion 4, and a variable motor 10 of the rotor 5 and a drive device 11 for the movable dam 8 are provided by measuring a resin pressure with a pressure sensor 9. In the kneading degree control device of the continuous kneading machine, which is provided with a control mechanism 12 for controlling at least one of the above, the control mechanism 12 controls the pressure sensor 9 to feed the blade A of the kneading blade part 3.
By providing a plurality of axial directions within a certain range D and E before and after the turning point C between the return vane B and the return vane B, and providing a computing unit 14 for computing the total of the pressure measurement values from the plurality of pressure sensors 9. is there.

[0012]

[Function] Addition of plastic materials such as plastic and rubber,
When supplied from the supply port 16 together with the filler and the like, the rotor 5 is rotated by the variable motor 10 to be sent from the screw portion 24 to the kneading blade portion 3 and subjected to kneading and shearing action to be plasticized and melted. The plasticized and melted resin material is mixed with the kneading blade portion 3.
7 between the circular section 19 and the movable dam 8 on the downstream side of the
Is strongly pushed out to the discharge port 17 by the feed blade portion 4, and is discharged to the post-processing device at a required pressure by the gear pump.

When the resin material enters the kneading blade portion 3, it receives a shearing force from the rotor 5 and the chamber 6. This shearing force gradually increases from the tip of the feed blade A, reaches its maximum at the turning point C, and decreases toward the rear end of the return blade B. The control mechanism 12 measures the maximum resin pressure Pmax / max with the pressure sensor 9 provided in the vicinity of the turning point C, and the arithmetic unit 13 determines whether the maximum shear stress τmax required to obtain the required quality of the resin material is generated. If a comparison calculation is performed and no occurrence occurs, the variable motor 10 of the rotor 5 is controlled to change the rotation speed of the rotor 5, and / or the drive device 11 of the movable dam 8 is driven to increase the size of the gap 7. The maximum resin pressure Pmax / ma that adjusts the height to generate the required maximum shear stress τmax.
Change to x or higher.

Further, the control mechanism 12 measures a maximum pressure Pmax at a plurality of positions within the ranges D and E by a plurality of axial pressure sensors 9 provided within a predetermined range D and E before and after the turning point C. Then, the measured values are integrated to calculate the total pressure (area) by the calculation unit 14, and the total pressure is compared and calculated to determine whether the total pressure is large enough to obtain the required quality of the resin material. If not, the variable motor 10 of the rotor 5 is controlled to change the rotational speed of the rotor 5, and / or the drive device 11 of the movable dam 8 is driven to adjust the size of the gap 7. Then, change the total pressure so as to generate more shear force than necessary.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, reference numeral 1 denotes a continuous kneader having the same structure as that of the prior art. A movable dam 8 that adjusts a gap 7 with the rotor 5 is provided between the wing portion 3 and the feed wing portion 4, and a variable motor 10 of the rotor 5 and a drive device of the movable dam 8 are measured by measuring a resin pressure with a pressure sensor 9. A control mechanism 12 for controlling at least one of 11 and 11 is provided.

The tip of the kneading blade portion 3 is bent at the center in the axial direction and the bending directions are opposite to each other. The tip of the kneading blade portion 3 is a feeding blade A from the center to the rear end thereof is a returning blade B. And generate a pressure for applying a shearing force to the resin material. The generation of the maximum pressure Pmax applied to the resin material depends on the number of chips of the kneading blade portion 3, and is 6 in the case of 6 chips and 4 in the case of 4 chips,
The pressure sensor 9 is arranged at a position where the maximum pressure Pmax can be measured.

Maximum pressure Pma in the axial direction of the rotor 5
The distribution of x becomes approximately maximum at the turning point C in the center. Therefore, if the maximum pressure Pmax at the turning point C is measured by the pressure sensor 9, the maximum resin pressure Pmax / max, which is the maximum pressure in the continuous kneading machine 1, can be measured. The constant ranges D and E before and after the turning point C are ranges in which shearing force that seriously affects the kneading quality is generated, and the range D is folded from a position of about 1/3 (from the tip) of the feed blade A. Point C
Range E is about 1/3 of the return wing B from the turning point C
Up to the position (from the tip).

The control mechanism 12 has a turning point C between the feeding blade A and the returning blade B of the kneading blade portion 3 and a certain range D before and after the turning point.
Plural (four) pressure sensors 9a, 9b, 9c, 9 in E
d is provided. These pressure sensors 9a, 9b, 9
c and 9d are arranged in parallel and connected to the arithmetic units 13 and 14, and both arithmetic units 13 and 14 are connected to the variable motor 10 and the drive device 11 via a drive unit (not shown).

In FIG. 2, the calculation unit 13 has Pmax / m.
It has an ax detection unit, a Pmax / max setting unit, a comparison calculation unit, and the like, and selects the maximum pressure in the axial direction from the maximum pressures Pmax measured by the pressure sensors 9a, 9b, 9c, 9d,
The maximum resin pressure Pmax / max is compared with a set value to calculate the height, and if it is low, a correction command signal is issued to the variable motor 10, the drive device 11 and the like.

However, since the maximum resin pressure Pmax / max is generated substantially at the turning point C, if the pressure sensor 9a is provided at the turning point C, the Pmax / max detecting section is not required, and the maximum value of a single position can be obtained. It can be controlled simply by measuring the pressure. The calculation unit 14 includes a Pmax integration unit, a Pmax integration value setting unit, a comparison calculation unit, and the like, and the pressure sensors 9a and 9a.
b, 9c, 9d integrates all the maximum pressures Pmax measured to calculate the total pressure (area), and compares the total pressure with a set value to calculate the high and low, and if it is low, the variable motor 10,
A correction command signal is issued to the drive device 11 and the like.

Either one of the arithmetic units 13 or 14 may be used, or both of them may be used at the same time.
The drive device 11 may be controlled either or both simultaneously. Although there is a method of controlling the motor of the feeder for supplying the material to the supply port 16,
Since the throughput varies, downstream equipment (for example, a granulator) is adversely affected, which is not desirable.

[0022]

According to the present invention described in detail above, since the pressure sensor 9 of the control mechanism 12 is provided in the vicinity of the turning point C between the feeding blade A and the returning blade B of the kneading blade portion 3, the resin material is used. Since the pressure at the melting start point can be measured, and this pressure is controlled by at least one of the variable motor 10 of the rotor 5 and the drive device 11 of the movable dam 8, the kneading quality can be stricter and quicker. Can be controlled.

Further, according to the present invention, the control mechanism 12 causes the pressure sensor 9 to axially fall within a certain range D and E before and after the turning point C between the feeding blade A and the returning blade B of the kneading blade portion 3. Along with providing a plurality, the arithmetic unit 14 for calculating the total of the plurality of pressure measurement values is provided, so that the pressure in the vicinity thereof including the substantially melting start point of the resin material can be measured at a plurality of points,
Further, since the total of the plurality of pressure measurement values is controlled by at least one of the variable motor 10 of the rotor 5 and the drive device 11 of the movable dam 8, it becomes possible to control the kneading quality more strictly and quickly.

The present invention is particularly useful for improving the rubber dispersibility of polypropylene, which is a block copolymer, and the fish-eye erasing property of high-density polyethylene.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram of the control mechanism.

FIG. 3 is an explanatory diagram showing a maximum pressure generation state of a 6-chip rotor.

FIG. 4 is an explanatory diagram showing a maximum pressure generation state of a 4-chip rotor.

FIG. 5 is an explanatory view showing an entire kneading degree control device of a conventional kneading machine.

[Explanation of symbols]

 1 continuous kneading machine 2 kneading degree control device 3 kneading blade part 4 feeding blade part 5 rotor 6 chamber 7 gap 8 movable dam 9 pressure sensor 10 variable motor 11 drive device 12 control mechanism 13 computing unit 14 computing unit A feeding blade B return blade C Folding point D range E range

Claims (2)

[Claims] 1. Two rotors 5 having a kneading blade portion 3 and a feeding blade portion 4 are arranged in a chamber 6, and a rotor 5 and a rotor 5 are provided in the chamber 6 between the kneading blade portion 3 and the feeding blade portion 4. Is provided with a movable dam 8 for adjusting the gap 7, and a control mechanism 12 is provided for measuring at least one of the variable motor 10 of the rotor 5 and the drive device 11 of the movable dam 8 by measuring the resin pressure with the pressure sensor 9. In the kneading degree control device of the continuous kneading machine, the pressure sensor 9 of the control mechanism 12 is provided in the vicinity of the turning point C between the feeding blade A and the returning blade B of the kneading blade part 3. Machine kneading degree control device. 2. Two rotors 5 having a kneading blade portion 3 and a feeding blade portion 4 are arranged in a chamber 6, and a rotor 5 and a rotor 5 are provided in the chamber 6 between the kneading blade portion 3 and the feeding blade portion 4. Is provided with a movable dam 8 for adjusting the gap 7, and a control mechanism 12 is provided for measuring at least one of the variable motor 10 of the rotor 5 and the drive device 11 of the movable dam 8 by measuring the resin pressure with the pressure sensor 9. In the kneading degree control device of the continuous kneading machine, the control mechanism 12 causes the pressure sensor 9 to axially fall within a certain range D and E before and after the turning point C between the feeding blade A and the returning blade B of the kneading blade portion 3. A kneading degree control device for a continuous kneading machine, wherein a plurality of the kneading degree control devices are provided and a calculation unit 14 that calculates the total of the pressure measurement values from the plurality of pressure sensors 9 is provided.