JPH1024412A - Rubber milling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain a lot-to-lot or a batch-to-batch property irregularity of a milled rubber to a minimum by introducing a rubber temperature immediately before supplying to a rubber milling apparatus to a drive control apparatus through an operation device. SOLUTION: A signal which is inputted to a drive control apparatus 22 is applied to an algorithm program relating to a pre-incorporated working electric energy, a milling time and a deviation from a base temperature of a supplied rubber. This program performs a correction corresponding to a temperature difference against the base temperature of the input temperature signal at least against either the base electric energy or the base milling time. Then, the drive control apparatus 22 outputs the drive control signal under at least either of a correct milling condition of a corrected electric energy or a milling time to a Banbury mixer 5. The Banbury mixer 5 performs a rubber milling work by a corrected electric energy in each batch based on this output.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a natural rubber material,
From kneading a synthetic rubber material or a blend of these rubber materials to non-pro kneading a rubber material excluding a cross-linking agent into a rubber material, and a kneading method for each kneading stage from a pro kneading process in which a cross-linking agent is added, particularly The present invention relates to a rubber kneading method capable of maintaining excellent kneading quality and realizing high rubber kneading productivity without causing excessive or insufficient rubber kneading.

[0002]

2. Description of the Related Art The rubber kneading apparatus referred to here is generally a kneading machine such as a Banbury mixer or a kneader, and sometimes includes an open roll. The temperature of the rubber material described at the beginning immediately before being supplied to the rubber kneading apparatus generally ranges from about 10 to 60 ° C. depending on the environment in which the rubber material is placed.

However, the rubber kneading conditions, that is, the amount of power (kwh) and kneading time to be applied from the beginning to the end of kneading of rubber, are based on a conventional empirical rule, even if temperature changes due to seasons such as summer and winter are taken into consideration. At present, there is no clear numerical standard for changing kneading conditions, which is determined by the know-how of the individual and the know-how of the individual. In addition, no measures are taken to change the kneading conditions for the rubber temperature difference immediately before the supply for each rubber kneading (for each batch) and for each lot.

[0004]

Originally, rubber kneading had a great effect on the characteristics or properties of the rubber kneaded, but most of the time, since little attention was paid to the temperature immediately before kneading the rubber material. Hard kneading conditions are rarely applied to rubber materials. As a result, appropriate kneading energy (mainly shearing energy) is not given to the kneaded rubber material, and there are large variations in properties, for example, viscosity, temperature, dispersion of rubber chemicals, etc. between kneaded rubber lots and batches. It is unavoidable.

[0005] Further, since the change of the kneading conditions depends on humans, it is almost impossible to take a sufficient measure. For example, in the case of professional kneading,
In the summer, there are cases of rubber scorch (scorch), which indicates the progress of partial cross-linking, blooming inconvenience due to the transfer of sulfur, etc. to the surface, and in winter, poor kneading (insufficient kneading). . In some cases, the kneading time, which is a concern for the latter kneading, is extended to an unnecessary amount, and power energy is lost.

Further, since the change of the kneading conditions by hand requires a great number of man-hours, even if the temperature change is grasped for each batch or lot of the rubber kneaded rubber material, the kneading condition setting change corresponding to the change is dealt with. Never.

[0007] From the above, the object of the present invention is to provide:
In order to completely eliminate the above-mentioned problems, the rubber kneading condition setting by manual operation based on personal know-how and conventional imperfect empirical rules is eliminated, and the rubber kneading target is automatically and under minimum power energy use. To provide a rubber kneading method capable of performing rubber kneading under the most appropriate kneading conditions for a rubber material, and thus minimizing property variations between kneaded rubber lots and batches. It is in.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, a rubber kneading method according to the present invention detects the temperature of rubber immediately before being supplied to a rubber kneading apparatus for each batch during rubber kneading. The temperature is input to the arithmetic device as an electric signal, and the arithmetic device that receives the input signal compares the input signal with the reference temperature information stored in advance in the device and generates a signal corresponding to a temperature difference between positive and negative. The output is output to the operation control device of the rubber kneading device, and in response to the output signal, the operation control device adjusts the reference power amount supplied to the rubber kneading device and the reference value of the rubber kneading device, which are stored under the reference temperature. At least one of the kneading times is subjected to a correction corresponding to the output signal, and at least one of the corrected power amount and the corrected kneading time is output to the rubber kneading device according to the output information. Beam kneading apparatus which comprises carrying out the rubber kneading.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail based on an embodiment. FIG. 1 is a diagram showing a side view schematically illustrating a main part of a rubber kneading apparatus and a block diagram of a control system combined with the apparatus.

[0010] One batch of rubber-kneaded rubber 1 in the form of a sheet is transferred by a conveyor 2 to a supply conveyor 3 whose one end is located near the inlet of a Banbury mixer 5 enclosed by a dashed line, and the rubber 1 in the illustrated example is a conveyor. 3 to obtain a predetermined batch weight. The sheet-like rubber 1 is often a non-pro-kneaded rubber, and the rubber material to be kneaded at the beginning is often in the form of a block as shown in the drawing, and the rubber 1a is supplied by the transfer conveyor 4. Transfer to conveyor 3. In kneading the rubber, the rubbers 1 and 1a are put into the Banbury mixer 5 in the direction of arrow A in the figure.

The Banbury mixer 5 is of a conventional type, and has two rotors 6 and 7 rotating in different directions, a kneading chamber 8 having a structure for passing cooling water (not shown), and a double-headed arrow B in the drawing. The supply rubber is rotatably received (in the position shown in the drawing) and closed after the reception, a pressure device (floating weight) 10 for pushing the rubber received in the Banbury mixer 5 into the kneading chamber 8, and the kneaded rubber is moved downward. And a drop door 11 that discharges the liquid to the outside.

In FIG. 1, temperature detectors 20 and 20a located above the rubbers 1 and 1a to be kneaded, an arithmetic unit 21,
A temperature detector that forms a control system with the operation control device 22 and is installed inside the kneading chamber 8 of the Banbury mixer 5 as necessary;
For example, a thermocouple or thermistor 23 is added to this control system.

Using the Banbury mixer 5 as an example of the above-described rubber kneading apparatus, its peripheral devices 2, 3, and 4, and the control systems 20, 21, and 22, batch kneading of the rubbers 1 and 1a is performed according to the method described below. I do. First, the temperatures of the rubbers 1 and 1a immediately before being supplied to the Banbury mixer 5 are detected by a temperature detector, for example, infrared temperature sensors 20 and 20a, and the detected temperature is input to the arithmetic unit 21 as an electric signal.

The arithmetic unit 21 stores in advance information corresponding to a reference temperature immediately before rubber kneading of the rubber to be kneaded, for example, 25 ° C. The arithmetic unit 21 compares this reference temperature information with the input temperature signal. Then, a temperature difference between the input temperature signal and the reference temperature is calculated. At this time, it is needless to say that a positive or negative sign is given, and a signal corresponding to the temperature difference is output to the next operation control device 22 of the Banbury mixer 5.

The operation control device 22 stores an appropriate reference electric power amount to be supplied to the Banbury mixer 5 at the reference temperature and an appropriate reference kneading time at the reference temperature in accordance with the type of the rubber 1, 1a to be kneaded. Let it be. The term “appropriate” as used herein means that the rubber kneading result can provide the desired kneaded rubber properties such as viscosity, kneading temperature, and dispersion in the case of rubber compounded with rubber chemicals. These reference power amounts and times can be obtained in advance, for example, by experiments, or determined by simulating data from laboratory data or similar rubber type data, and can be obtained by making corrections in actual operation as necessary. it can.

Therefore, the signal input to the operation control device 22 is applied to a program of an algorithm relating to the power consumption and kneading time previously incorporated in the operation control device and the deviation of the temperature of the supplied rubber from the reference temperature. For at least one of the reference electric energy and the reference kneading time,
A correction corresponding to the temperature difference described above is made. That is, the correction is only one of the electric energy, the kneading time, or both the electric energy and the kneading time, and any one of the three kneading conditions can be appropriately selected depending on the type of rubber. it can.

The operation control device 22 outputs an operation signal under at least one of the corrected electric energy and the kneading time to the Banbury mixer 5, and the Banbury mixer 5 corrects the batch for each batch based on the output. Whether the rubber kneading operation is performed with the electric energy (the kneading time at that time is the reference time) or kneading until the corrected kneading time has elapsed (the electric energy at that time is the reference amount), or both the corrected electric energy and kneading Perform rubber kneading in time.

As is apparent from the above description, the rubber kneading can be performed under the optimum condition suitable for the rubber temperature immediately before the rubber is supplied to the Banbury mixer 5, so that the rubber kneading can be performed with sufficient and necessary energy for the rubber kneading. As a result, the desired value can be obtained for the viscosity and temperature of the kneaded rubber, and in some cases, the dispersion, and the variation between batches and lots can be greatly reduced.

In addition, it is possible to completely eliminate problems such as the occurrence of rubber scorch and bloom in summer and insufficient kneading in winter, which are often seen in the past, and no unnecessary power is wasted. The kneading time can be completely extended, and the improvement of the quality of the kneaded rubber and the improvement of the productivity can be achieved at the same time.

In setting the reference electric energy and the kneading time, a plus / minus allowable range is provided in addition to their median value, and the electric energy and the electric power corrected and output from the operation control unit 22 through the arithmetic unit 21 are set. Kneading time is also positive
If a negative tolerance is provided, the practicality is further improved.

Reference numeral 23 shown in FIG. 1 denotes a thermocouple or thermistor temperature detector.
Reference numeral 3 denotes a device for forming a kind of feedback system for detecting the temperature of the rubber just before the completion of the rubber kneading and transmitting the detected temperature signal to the operation control device 22. The application of this feedback system is effective for controlling the temperature at which the rubber is kneaded, and the feedback system is combined with the system from the temperature detector 20 to the operation of the Banbury mixer 5 via the operation control device 22 as described above. It contributes to further improvement of the effect.

As described above, the Banbury mixer 5 is added to the rubber kneading device.
However, the present invention can also be applied to a kneader or an open roll such as a kneader in which a pair of blades mesh with each other and rotate.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Pro rubber obtained by kneading sulfur as a cross-linking agent and a vulcanization accelerator into 190 kgf of non-pro rubber per batch according to the method according to the embodiment and the conventional method using two Banbury mixers 5 of the same type alternately. The kneading was carried out for 50 batches each. The rubber temperature immediately before charging into the Banbury mixer 5 is 1 in both the embodiment and the conventional example, assuming summer and winter.
A relatively wide temperature range of 0 to 60 ° C was set. This temperature is a value manually measured in advance, but when it is detected by the temperature detector 20 in an attempt, almost the same value is shown.

The reference temperature in the examples was set at 30 ° C., and therefore, the temperature deviation of the rubber immediately before the injection was − (minus) 20 to + (plus) 30 ° C.
The reference electric energy supplied to the Banbury mixer 5 at the reference temperature of 30 ° C. is 8.0 kWH, and the reference kneading time is 1 minute and 20 seconds. By the way, the temperature immediately after the kneaded rubber drops is 10
It was set at 0 to 130 ° C.

When the output signal from the arithmetic unit 21 was checked during the kneading operation, it was found that the temperature deviation of -20 to +
A voltage corresponding to 30 ° C. is output. As a result, a voltage in this range is input to a program in the operation control device 22 each time.
6.0 to 9.5 kWH, kneading time is +15 seconds to -20
It was corrected to the range of 1 minute 00 seconds to 1 minute 35 seconds. These are all output on a chart.

After all, the operation signal of both the corrected electric energy and the corrected kneading time is output to the Banbury mixer 5,
In accordance with this, the Banbury mixer 5 was unmanned and two units alternately kneaded the pro-rubber. On the other hand, in the rubber kneading by the conventional method, the electric energy and the kneading time were manually set to be constant according to an empirical rule, and the professional rubber kneading was also performed by alternately operating two units.

As a result of the rubber kneading according to the examples, the temperature of the dropped rubber was 110 to 120 ° C., which was within the initial target temperature range, there was no scorch portion, and no insufficient kneading portion was found. On the other hand, the rubber temperature of the conventional example is in a wide range of 95 to 135 ° C., and the high-temperature side rubber has a burnt portion and must be discarded. On the other hand, the low-temperature side rubber has insufficient kneading. In short,
The conventional problem was reconfirmed. In the examples, the dispersion was small and the expected values were obtained with respect to the viscosity and the dispersion of the carbon black. In the conventional example, as can be seen from the above, the dispersion was large and unsatisfactory.

[0028]

According to the present invention, the kneaded rubber can be obtained with a small investment such that the rubber temperature immediately before being supplied to the rubber kneading device is introduced into the operation control device via the arithmetic unit.
High productivity that minimizes variations between lots and batches, has high quality with the best properties, requires minimal use of energy, and eliminates waste such as scrap products. Can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram combining a schematic side view and a control system block diagram of an apparatus for realizing a rubber kneading method according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a Rubber 2, 3, 4 Conveyor 5 Banbury mixer 6, 7 Rotor 8 Kneading room 9 Window 10 Pressurizing device 11 Drop door 20 Temperature detector 21 Computing device 22 Operation control device 23 Temperature detector

Claims (2)

[Claims] At the time of kneading a batch of rubber, the temperature of the rubber immediately before being supplied to a rubber kneading apparatus is detected for each batch, and the detected rubber temperature is input to an arithmetic unit as an electric signal. The device compares the reference temperature information previously stored in the device with the input signal, outputs a signal corresponding to a temperature difference of positive or negative to the operation control device of the rubber kneading device, and receives the output signal to operate the device. The control device adjusts at least one of the reference power amount to be supplied to the rubber kneading device and the reference kneading time of the rubber kneading device, which match under the reference temperature, so as to correspond to the output signal. A rubber kneading method, characterized in that at least one of an electric power amount and a correction kneading time is output to a rubber kneading apparatus, and the rubber kneading apparatus performs rubber kneading in accordance with the output information. 2. The method according to claim 1, wherein the reference electric energy and the reference kneading time each include a median value and a permissible range thereof, and the correction by the output signal from the arithmetic unit covers both the median value and the permissible range. Item 1. The method according to Item 1.