JPH04265707A - Method for controlling kneading of rubber kneader - Google Patents

Abstract

PURPOSE:To uniformize the physical properties of matter to be kneaded by employing a current control method to which the same principle as a Mooney tester is applied to perform control corresponding to the phycial properties of the matter to be kneaded. CONSTITUTION:At the time of kneading, a kneading rotor 3 is driven by a motor 9. The change of the load current of the motor 9 is continuously detected by a current detector 10 and, when the detected current value becomes a specific level, an oil charging command and a kneading completing command are issued from an operator 12 to perform respective operations.

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 kneading in a rubber kneader.

0002

[Prior Art] As a kneading control method when adding carbon black, chemicals, etc. to raw rubber and kneading it in a rubber kneading machine,
Conventionally, there are temperature control, time control, power control, and combinations of these controls. For example, the temperature control method is
The temperature of the material to be kneaded is measured to obtain a temperature curve as shown in A in FIG. If the kneading continues and the temperature rises to a predetermined temperature, at that point t2
This method completes the kneading process.

[0003] The time control method is a method in which the time from the start of kneading is measured and oil is added or kneading is completed at a predetermined time. In addition, the power control method integrates the amount of power of the motor that drives the kneading rotor (the area of the shaded area below the current curve B shown in Figure 3), and determines when to add oil and complete kneading based on the amount of power. It is a method of control.

0004

[Problems to be Solved by the Invention] Conventional temperature control, time control, and power control do not necessarily have a clear correlation with the physical properties of the material to be kneaded in the rubber kneading machine, that is, the rubber compound, and it is difficult to make the physical properties uniform. There are unavoidable flaws. In particular, the Mooney testing machine is a representative testing machine for evaluating the plasticity of rubber compounds, and this Mooney testing machine is widely used. Conventional control methods are used to determine the Mooney degree of an object, but since the principle is completely different from that of the Mooney tester, it is difficult to grasp the mutual correlation, which poses a problem.

In view of such conventional problems, the present invention employs a current control method that applies the same principle as the Mooney tester, and enables control in accordance with the physical properties of the material to be kneaded.

[0006]

[Means for Solving the Problems] The present invention continuously detects the load on the kneading rotor 3 during kneading as a current value when adding carbon black, chemicals, etc. to raw rubber and kneading it in the rubber kneading machine 1. When the current value reaches a specific level, operations such as adding oil and completing kneading are performed.

[0007]

[Embodiment] Hereinafter, one embodiment of the present invention will be described in detail based on the drawings. Fig. 2 shows a rubber kneading machine 1, 2 is a chamber, and within this chamber 2 are two kneading rotors 3.
is rotatably provided. 4 is a discharge door at the bottom of the chamber 2, and 5 is an inlet for raw rubber. 6 is a floating weight for applying pressure to the material to be kneaded in the chamber 2, and the piston rod 8 of the cylinder 7
is connected to.

FIG. 1 shows a block diagram of the control system. In FIG. 1, 9 is a motor that drives the kneading rotor 3;
is a current detector which continuously detects the load on the kneading rotor 3 during kneading as a current value. Reference numeral 11 denotes a setting device for setting the current value at the time of oil injection, the current value at the completion of kneading, etc. 12 is a computing unit such as a CPU, which compares the current value continuously detected by the current detector 13 with the level of the set current value set by the setting device 11, performs calculations, and issues an oil injection command to the operating unit 14 to complete kneading. It is designed to perform operations according to commands such as commands.

When kneading is performed using the rubber kneader 1, raw rubber, carbon black, chemicals, etc. are introduced, and then the kneading rotor 3 is rotated by the motor 9 to continuously knead. A current detector 10 detects a change in the load current of the motor 9 during this kneading. That is, the load on the kneading rotor 3 is continuously detected as a current value. The current curve at this time is as shown in B shown in FIG. Therefore, a predetermined level preset by the setting device 11 and the detected current value are compared in the calculator 12, and when the detected current value reaches the set level I1, an oil injection command is issued, and when the detected current value reaches the set level I2, a kneading completion command is issued. are output respectively, and each operation is performed according to these commands to make the degree of plasticity uniform for each batch.

According to such a current control method, the load on the kneading rotor 3 varies depending on the physical properties of the materials to be kneaded, so the control principle is the same as that of the Mooney tester, and the correlation with the measured values of the Mooney tester is Become something to do. Next, the test results are shown. That is, a comparative test was conducted between the control method of the present invention and conventional temperature, time, and power control methods using materials blended at a polymer NR/SBR ratio of 70/30.
Mooney viscosity, modulus, and specific gravity were determined for each control method.

[0011] Mooney performed n=10 samplings under the condition of ML1+4 and 100°C, and determined the dispersion thereof. The modulus was determined by vulcanizing at 150° C. for 30 minutes, cooling to room temperature, and then performing a tensile test using JIS/dumbbell punching. In addition, n
The variation was determined for =8 samples.

[0012] The specific gravity was determined using a specific gravity solution using a product that was vulcanized under vulcanization conditions of 150°C for 30 minutes. In addition, n
The variation was determined using samples of =8. The results obtained in these tests are expressed as an index, with the power control result set as 100, as shown in Table 1. From this result, it can be seen that the current control method is the best in terms of Mooney degree, modulus, and specific gravity.

[0013]

[Table 1]

[0014]

According to the present invention, when adding carbon black, chemicals, etc. to raw rubber and kneading it in the rubber kneading machine 1, the load on the kneading rotor 3 during kneading is continuously detected as a current value, and the current A method is adopted in which operations such as adding oil and completing kneading are performed when the value reaches a certain level, and since it is controlled using the same principle as the Mooney tester, it is possible to control according to the physical properties of the material to be kneaded. It is possible to make the physical properties uniform.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a control system.

FIG. 2 is a partially cutaway front view of the rubber kneading machine.

FIG. 3 is a control characteristic diagram.

[Explanation of symbols]

1 Rubber kneading machine 3 Kneading rotor 9 Motor 10 Current detector 11 Setting device 12 Arithmetic unit

Claims (1)

[Claims] Claim 1: When adding carbon black, chemicals, etc. to raw rubber and kneading it in a rubber kneading machine (1), the load on the kneading rotor (3) during kneading is continuously detected as a current value, and the current value is A method for controlling kneading in a rubber kneading machine, characterized in that operations such as adding oil and completing kneading are performed when a specific level is reached.