JP2019093590A - Method and apparatus for kneading rubber material - Google Patents

Abstract

To provide a method and an apparatus for kneading a rubber material, with which a rubber material of stable quality can be obtained, while preventing jetting of a compounding agent inputted to a kneading chamber in a hermetically sealed type kneading machine.SOLUTION: A method for kneading a rubber material includes the steps of: inputting a rubber material R composed of a raw material rubber G and a compounding agent N to a kneading chamber 4; then detecting a contact state between the rubber material R inputted to the kneading chamber 4 and an underside 8a of a ram weight 8 by using a state sensor 13, when the ram weight 8 is moved downward so that the kneading chamber 4 is in a sealed state; and kneading the rubber material R by rotating rotors 3, while a control part 12 adjusts the magnitude of ram pressure applied to the ram weight 8 against the rubber material inputted to the kneading chamber 4, on the basis of detection data of the state sensor 13.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method and apparatus for kneading a rubber material, and more specifically, a rubber material capable of obtaining a rubber material having stable quality while preventing ejection of a compounding agent introduced into a kneading chamber of a closed type kneading machine. The present invention relates to a kneading method and apparatus.

  When manufacturing rubber products such as tires, there is a kneading step of obtaining an unvulcanized rubber material by dispersing various compounding agents in a raw material rubber and kneading. In the kneading step, for example, a closed-type kneader is used. In the closed-type kneader, a rotor is provided inside the kneading chamber, and a ram weight that moves up and down is disposed above the kneading chamber. The raw material rubber and various compounding agents introduced into the kneading chamber are kneaded by the rotating rotor in the kneading chamber in a state in which the upper portions are closed by ram weights (see, for example, Patent Document 1).

  At the time of this kneading, the ram weight functions as a lid of the kneading chamber to prevent the compounding agent from spouting from the kneading chamber. However, immediately after the compounding agent is put into the kneading chamber, the apparent volume in the kneading chamber is large, and the ram weight is lowered to the lower limit position. At this time, if the kneading chamber is filled with the rubber material (raw rubber and compounding agent), an excessive pressure acts on the rubber material in the kneading chamber, and the compounding agent which tends to scatter is from the gap between the kneading chamber and the ram weight. It may spout out of the kneading chamber. When the compounding agent spouts from the kneading chamber, the amount of the compounding agent is insufficient in the kneaded rubber material and the quality varies.

  On the other hand, when the kneading step is performed in a state where the ram weight is disposed above the lower limit position, the compounding agent is sufficiently dispersed in the raw rubber and it becomes difficult to knead. Also in this case, since the quality of the kneaded rubber material varies, a stable rubber material of quality can not be obtained.

JP-A-9-254148

  An object of the present invention is to provide a rubber material kneading method and apparatus capable of obtaining a rubber material having stable quality while preventing the ejection of the compounding agent input to the kneading chamber of the closed-type kneader.

  The rubber material kneading method of the present invention for achieving the above object is to put a rubber material comprising a raw material rubber and a compounding agent into a kneading chamber of a closed type kneading machine, and close the kneading chamber with ram weight. In the kneading method of a rubber material in which the rubber material is kneaded by rotating a rotor provided in the kneading chamber, the contact state between the rubber material introduced into the kneading chamber and the lower surface of the ram weight Are controlled by the state sensor, and control is performed to adjust the magnitude of the ram pressure applied by the ram weight to the rubber material introduced into the kneading chamber based on the detection data from the state sensor. It is characterized by

  The rubber material kneading apparatus according to the present invention has a rotor provided inside the kneading chamber, and a ram weight capable of vertically moving above the kneading chamber to close the kneading chamber. In a rubber material kneading apparatus provided with a closed type kneader in which a rubber material composed of a raw material rubber and a compounding agent charged into the kneading chamber is kneaded by the rotating rotor, the kneading with the lower surface of the ram weight is performed. The kneading chamber has a state sensor for detecting a contact state with the rubber material introduced into the chamber, and a control unit for receiving detection data from the state sensor, and based on the detection data from the state sensor, the kneading chamber The controller is configured to adjust the magnitude of the ram pressure applied by the ram weight to the rubber material introduced into the housing.

  According to the present invention, the ram pressure applied to the rubber material by the ram weight is detected based on the detection data of the state sensor that detects the contact state between the rubber material supplied to the kneading chamber and the lower surface of the ram weight. Control to adjust the size is performed. Therefore, it is possible to appropriately adjust the ram pressure in accordance with the volume of the rubber material charged into the kneading chamber. Along with this, excessive ram pressure is applied to the rubber material, and it becomes possible to prevent the problem that the compounding agent which is easily scattered is jetted out of the kneading chamber. Therefore, it is advantageous to obtain a stable quality rubber material obtained by sufficiently dispersing a predetermined amount of the compounding agent with respect to the raw material rubber and kneading.

It is explanatory drawing which illustrates the kneading | mixing apparatus of the rubber material of this invention. It is AA sectional drawing of FIG. It is explanatory drawing which illustrates the state which makes the ram weight of FIG. 1 stop at the predetermined position above a lower limit position, and knead | mixes a rubber material. It is explanatory drawing which illustrates the state which makes the ram weight of FIG. 1 stop at a lower limit position, and knead | mixes a rubber material. It is explanatory drawing which illustrates another embodiment of the kneading | mixing apparatus of the rubber material of this invention. It is explanatory drawing which illustrates another embodiment of the kneading | mixing apparatus of the rubber material of this invention.

  Hereinafter, the method and apparatus for kneading a rubber material of the present invention will be described based on an embodiment shown in the drawings.

  The kneading | mixing apparatus 1 of the rubber material of this invention illustrated to FIGS. 1-2 knead | mixes unvulcanized rubber material R. As shown in FIG. The rubber material R is composed of a raw material rubber G and a plurality of non-vulcanizing compounding agents N, and is uniformly dispersed in the raw material rubber G by kneading to obtain a rubber material R having an appropriate viscosity. Do.

  Raw material rubber G includes natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), 1,2-polybutadiene, chloroprene rubber, butyl rubber, styrene-butadiene rubber (SBR), nitrile rubber (acrylonitrile rubber, Hydrogenated nitrile rubber), ethylene propylene diene rubber and the like can be exemplified. These are used individually by 1 type or in combination of 2 or more types. As the non-vulcanizing type compounding agent N, for example, a necessary one is suitably used from carbon black, silica, a silane coupling agent, zinc oxide, stearic acid and the like.

  The kneading apparatus 1 includes a closed-type kneading machine 2 such as a Banbury mixer, a state sensor 13, and a control unit 12 to which detection data detected by the state sensor 13 is sequentially input.

  The closed type kneader 2 includes a kneading chamber 4, a ram weight chamber 5 connected to the upper end opening 4 a of the kneading chamber 4 and extending upward, and a ram weight 8 capable of closing the kneading chamber 4. . The kneading chamber 4 is provided with a pair of opposed rotors 3 and an oil inlet 6a. Blades 3b are provided on the rotation shaft 3a of each of the rotors 3 so that the rotation shafts 3a arranged in parallel are rotationally driven by a drive motor. The rotation of the rotor 3 is controlled by the control unit 12.

  A discharge door 10 that opens and closes is provided at the bottom of the kneading chamber 4, and a thermometer 11 is provided with its tip exposed to the kneading chamber 4. The thermometer 11 sequentially detects the temperature of the rubber material R being kneaded in the kneading chamber 4. Temperature data from the thermometer 11 is input to the control unit 12.

  The ram weight 8 moving up and down inside the ram weight chamber 5 can close the upper end opening 4 a of the kneading chamber 4 when it moves downward to a predetermined position. The ram weight 8 is moved up and down by an elevating mechanism 8b such as a hydraulic cylinder. The drawing shows the lower limit position LP where the ram weight 8 can move (the position of the upper surface of the ram weight 8 when the ram weight 8 is most lowered) and the predetermined position PP above the lower limit position LP.

  As the vertical movement (upper and lower position) of the ram weight 8 is controlled by the control unit 12, the ram pressure applied by the ram weight 8 to the rubber material charged into the kneading chamber 4 is adjusted. In this embodiment, a pressure sensor 14 for sequentially detecting ram pressure is attached to the ram weight 8. Detection data detected by the pressure sensor 14 is input to the control unit 12. The ram weight chamber 5 is further provided with a rubber charging portion 6 b for charging the raw material rubber G and a compounding agent charging portion 9 for charging the compounding agent N from the hopper 7.

  A power meter 12 a is attached to the control unit 12. The instantaneous power required for the rotational drive of the rotor 3 is sequentially detected by the power meter 12a. The instantaneous power detected by the power meter 12 a is input to the control unit 12. The control unit 12 calculates the integrated power amount obtained by integrating the instantaneous power, and can grasp the power amount (load acting on the rotor 3) required for the rotational drive of the rotor 3 in an arbitrary kneading period. In addition, the rotation speed of the rotor 3 and the like are input to the control unit 12.

  The state sensor 13 detects a contact state between the rubber material R introduced into the kneading chamber 4 and the lower surface 8 a of the ram weight 8. In this embodiment, a load cell 13 a is attached to the lower surface 8 a of the ram weight 8 as the state sensor 13. If the lower surface 8a of the ram weight 8 is not in contact with the rubber material R introduced into the kneading chamber 4, the load cell 13a receives no load from the rubber material R, and the detected load data value becomes zero.

  On the other hand, when the lower surface 8a of the ram weight 8 comes into contact with the rubber material R introduced into the kneading chamber 4, the load cell 13a is pressed by the rubber material R and receives a load, so the value of load data detected by the load cell 13a is zero. It becomes a super value. As the lower surface 8a of the ram weight 8 comes into strong contact with the rubber material R introduced into the kneading chamber 4, the load cell 13a is more strongly pressed, so the value of the detected load data becomes larger. That is, the contact state (the presence or absence of contact or the strength of contact) of the lower surface 8a of the ram weight 8 and the rubber material R can be grasped by the size of the load data detected by the load cell 13a.

  Hereinafter, the procedure of the kneading method of the rubber material of the present invention will be described.

  First, a predetermined amount of raw material rubber G is charged into the kneading chamber 4 through the rubber charging portion 6b, and mastication is performed by rotating the rotor 3. After appropriately masticating the raw material rubber G, a predetermined amount of a necessary kind of compounding agent N is introduced into the kneading chamber 4 through the compounding agent introduction unit 9.

  Thereafter, in order to close the kneading chamber 4, the ram weight 8 is moved downward toward the lower limit position LP. When the ram weight 8 is moved downward, load data received by the lower surface 8 a of the ram weight 8 from the rubber material R introduced into the kneading chamber 4 is sequentially detected by the load cell 13 a.

  The volume of the compounding agent N may be excessive at a stage where the compounding agent N is not kneaded with the raw material rubber G immediately after the powdery compounding agent N is fed into the kneading chamber 4. In this case, the lower surface 8a comes into contact with the compounding agent N when the ram weight 8 moves downward to a certain extent above the lower limit position LP. When the ram weight 8 is moved downward to the lower limit position LP as it is, the compounding agent N is jetted out of the space between the kneading chamber 4 and the ram weight 8 to the outside of the kneading chamber 4 by the ram pressure. In this embodiment, based on load data detected by the load cell 13a sequentially input to the control unit 12, the control unit 12 determines that the lower surface 8a of the ram weight 8 contacts the rubber material R (compounding agent N) Ru.

  When the lower surface 8a of the ram weight 8 is determined to be in contact with the rubber material R (compounding agent N), the control unit 12 causes the ram weight 8 to be a predetermined position above the lower limit position LP as illustrated in FIG. Control is performed to stop at PP and adjust the applied ram pressure to less than the maximum ram pressure. The maximum ram pressure is the ram pressure applied to the rubber material R when the ram weight 8 is moved downward to the lower limit position LP. The rubber material R is kneaded inside the kneading chamber 4 by rotating the rotor 3 while the kneading chamber 4 is closed by the ram weight 8 in this manner. During the kneading, the oil is supplied to the rubber material R from the oil inlet 6a as appropriate.

  For example, every time the rubber material R is compounded, the limiting ram pressure which serves as an indication that the compounding agent N introduced into the kneading chamber 4 is not ejected from the kneading chamber 4 by testing and kneading the rubber material R beforehand is grasped beforehand. The limit ram pressure is input to the control unit 12 in advance. Then, it is preferable to control so that the ram pressure sequentially detected by the pressure sensor 14 does not exceed the limit ram pressure.

  On the other hand, when the volume of the rubber material R introduced into the kneading chamber 4 is not excessive, the rubber material R (not shown) is moved to the lower surface 8a even if the ram weight 8 is moved downward to the lower limit position LP or near the lower limit position LP. Formulation N) does not contact. Therefore, the ram weight 8 is moved downward to the lower limit position LP to close the kneading chamber 4. Since the volume of the rubber material R is not excessive, the compounding agent N does not jet out of the kneading chamber 4 by the ram pressure applied by the ram weight 8 moved downward to the lower limit position LP. Therefore, the rubber material R is kneaded inside the kneading chamber 4 by rotating the rotor 3 in this state.

  In this manner, the ram pressure can be appropriately adjusted according to the volume of the rubber material R (raw rubber G and the compounding agent N) supplied to the kneading chamber 4, and therefore, an excess ram pressure is applied. Thus, it is possible to prevent the problem that the compounding agent N, which is easily scattered, is jetted out of the kneading chamber 4. Therefore, the amount of the compounding agent N to be kneaded into the raw material rubber G does not run short, and it is possible to obtain a stable rubber material R of sufficiently dispersed and kneaded quality.

  By kneading, the compounding agent N is kneaded and dispersed to some extent into the raw material rubber G, and the volume of the rubber material R is reduced. As a result, the rubber material R does not contact the lower surface 8a of the ram weight 8 (it becomes difficult to contact), and the load data detected by the load cell 13a becomes zero or a value close to zero. That is, when the ram weight 8 is stopped at the same height position, the ram pressure decreases, so the ram pressure is increased based on the load data sequentially detected by the load cell 13a or the initial size is set. Adjustments such as back can be made. As a result, as illustrated in FIG. 4, it is also possible to lower the ram weight 8 to the lower limit position LP and knead the rubber material R.

  Also, the downward moving speed of the ram weight 8 can be adjusted based on the detection data of the load cell 13a. For example, when the load data detected by the load cell 13a is zero, the downward moving speed of the ram weight 8 is made relatively fast. On the other hand, when the load data detected by the load cell 13a exceeds zero, the downward moving speed of the ram weight 8 is relatively slowed. By controlling the downward moving speed of the ram weight 8 in this manner, the mixing chamber 4 is quickly closed by the ram weight 8 while preventing the powdery compounding agent N from being jetted out of the kneading chamber 4. Kneading can be started.

  Not only the load cell 13 a but also other sensors can be adopted as the state sensor 13. As the state sensor 13, as illustrated in FIG. 5, a distance sensor 13b for detecting the vertical distance L between the ram weight 8 and the rubber material R introduced into the kneading chamber 4; and as illustrated in FIG. A temperature sensor 13c that detects the temperature of the lower surface 8a of the ram weight 8 can also be used.

  The distance sensor 13b installed on the lower surface 8a of the ram weight 8 illustrated in FIG. 5 can sequentially detect the vertical distance L between the lower surface 8a and the rubber material R introduced to the kneading chamber 4. When the data value of the vertical distance L detected by the distance sensor 13 b is zero, it can be determined that the lower surface 8 a is in contact with the rubber material R. On the other hand, when the data of the vertical distance L is more than zero, it can be judged that the lower surface 8a is not in contact with the rubber material R. Therefore, the distance sensor 13 b can be used as the state sensor 13.

  The temperature sensor 13c installed on the lower surface 8a of the ram weight 8 illustrated in FIG. 6 can sequentially detect the temperature of the lower surface 8a. The contact of the rubber material R changes the temperature of the lower surface 8a. Therefore, whether or not the lower surface 8a is in contact with the rubber material R can be determined by the change in temperature data detected by the temperature sensor 13c. Therefore, the temperature sensor 13 c can be used as the state sensor 13.

  The various embodiments described above can also be applied when continuously kneading a plurality of rubber materials R in a plurality of batches. In this case, for example, the control of the ram pressure in the kneading can also be performed based on the control of the ram pressure in the batch kneaded before the kneading.

  In the case where a certain rubber material R is continuously kneaded in a plurality of batches, the upper end position of the rubber material R charged into the kneading chamber 4 in each batch does not largely change. Therefore, if the rubber material R of the batch that has been kneaded one time before the kneading is appropriately kneaded without causing the ejection of the compounding agent N, control of the ram pressure as in the case of the kneading in the batch The rubber material R can be kneaded appropriately.

  The various embodiments described above can be applied even when the rubber material R having the same composition as the rubber material R to be kneaded this time is kneaded previously. In this case, for example, the control of the ram pressure in the present kneading is performed based on the control of the ram pressure in the previous kneading. If the rubber material R is appropriately kneaded without the occurrence of the ejection of the compounding agent N by the previous kneading, the rubber material R is appropriately kneaded by controlling the ram pressure in the same manner as the kneading before. Can.

  The present invention can be applied not only to the case where the raw material rubber G and the non-vulcanization type compounding agent N are kneaded but also to the case where the raw material rubber G is mixed with the vulcanized type compounding agent N.

Reference Signs List 1 kneader 2 closed type kneader 3 rotor 3a rotary shaft 3b wing 4 kneading chamber 4a upper end opening 5 ram weight chamber 6a oil feeding portion 6b rubber feeding portion 7 hopper 8 ram weight 8a lower surface 8b elevating mechanism 9 combination agent feeding portion 10 discharging Door 11 Thermometer 12 Control unit 12a Power meter 13 Condition sensor 13a Load cell 13b Distance sensor 13c Temperature sensor 14 Pressure sensor G Raw rubber N Compounding agent R Rubber material

Claims (8)

The rubber material consisting of the raw rubber and the compounding agent is put into the kneading chamber of the closed type kneading machine, the kneading chamber is closed by the ram weight, and the rotor installed in the kneading chamber is rotated. In a method of kneading a rubber material for kneading a rubber material,
A contact state between the rubber material introduced into the kneading chamber and the lower surface of the ram weight is detected from a state sensor, and the rubber material introduced into the kneading chamber is detected based on detection data by the state sensor. On the other hand, control is performed to adjust the magnitude of the ram pressure applied by the ram weight, and the method of kneading a rubber material.   The kneading method of the rubber material according to claim 1 which adjusts the downward moving speed of said ram weight based on said detection data.   The method according to claim 1, wherein a load cell attached to the ram weight is used as the state sensor.   The kneading method of the rubber material according to claim 1 or 2 using a distance sensor which detects an up-and-down distance with said ram weight and said rubber material thrown into said kneading room as said state sensor.   The method for kneading a rubber material according to claim 1 or 2, wherein a temperature sensor which detects the temperature of the lower surface of the ram weight is used as the state sensor.   When the rubber material is continuously kneaded in a plurality of batches, the control of the ram pressure in the kneading is performed based on the control of the ram pressure in the batch kneaded before the kneading. A method of kneading a rubber material according to any one of the above.   When the rubber material having the same composition as the rubber material to be kneaded this time is kneaded before, the control of the ram pressure in the current kneading is performed based on the control of the ram pressure in the previous kneading. The kneading method of the rubber material in any one of 1-5. Raw material rubber introduced into the kneading chamber, having a rotor provided inside the kneading chamber, and a ram weight which can move up and down above the kneading chamber to close the kneading chamber. In a rubber material kneading apparatus provided with a closed type kneading machine in which a rubber material comprising an oil and a compounding agent is kneaded by the rotating rotor.
A state sensor for detecting a contact state between the lower surface of the ram weight and the rubber material introduced into the kneading chamber, and a control unit to which detection data from the state sensor is input, the detection by the state sensor The rubber material characterized in that the magnitude of the ram pressure applied by the ram weight to the rubber material introduced into the kneading chamber is adjusted by the control unit based on data. Kneader.

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