JP2020062756A - Method and system for kneading rubber material - Google Patents

Abstract

To provide a method and system for kneading a rubber material capable of kneading a rubber material more efficiently by using a closed kneading machine having a variable rotor gap structure arranged facing each other.SOLUTION: A rubber material R is kneaded while, performing an adjusting operation of adjusting so as to adjust an area S of a gap between a pair of rotors 3 in a top view to be relatively small when the rubber material R is unevenly distributed between the pair of rotors 3, and adjusting so as to adjust the area S to be relatively large when the rubber material R is unevenly distributed at a position other than between the pair of rotors 3, through control of a variable mechanism 8 by a control unit 12, based on, during a preset adjustment period in a kneading process, position data of the rubber material R in a kneading chamber 5, and phase data generated by rotation of the pair of rotors 3 arranged inside the kneading chamber 5 so as to face each other.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a kneading method and system for kneading a rubber material, and more specifically, kneading a rubber material using a closed kneading machine having a variable rotor gap and facing each other. A method and system.

  Various rubber members are used when manufacturing rubber products such as tires. As a facility for kneading a rubber material which is a material of a rubber member, a closed type kneading machine (so-called Banbury mixer) in which a pair of rotors are placed inside a kneading chamber is known. There is also known a closed kneading machine having a variable structure in which the rotor interval between the rotors is variable (see, for example, Patent Document 1).

  The rubber material is kneaded in the kneading chamber with shearing force applied. The inventor of the present application has made various studies, paying attention to the fact that a shearing force applied to a rubber material can be flexibly changed with a kneader having a variable rotor spacing. As a result, the inventors of the present invention have created the invention capable of more efficiently kneading a rubber material.

JP 62-234533 A

  An object of the present invention is to provide a kneading method and system for a rubber material, which can knead the rubber material more efficiently by using a closed kneading machine having a structure in which rotor intervals are variable and which are arranged opposite to each other.

  A kneading method of a rubber material of the present invention for achieving the above object is a closed type in which a rubber material containing a raw rubber and a compounding agent is a structure in which a rotor interval of a pair of rotors placed inside a kneading chamber is variable. In a kneading method of a rubber material to be kneaded using a kneading machine, during a preset adjustment period in a kneading step, based on position data of the rubber material in the kneading chamber, an adjusting operation for adjusting the rotor interval is performed. It is characterized in that the rubber material is kneaded while being performed.

  A kneading system for a rubber material of the present invention is a kneading chamber into which a rubber material containing a raw rubber and a compounding agent is charged, a pair of rotors placed inside the kneading chamber, and rotor intervals of the pair of rotors. In a kneading system for a rubber material, which includes a closed type kneading machine having a variable mechanism for making it variable and a control section for controlling the operation of the closed type kneading machine, position data of the rubber material in the kneading chamber is acquired. A position sensor for adjusting the rotor spacing by adjusting the variable mechanism by the control unit based on the position data acquired by the position sensor during a preset adjustment period in the kneading process. It is characterized in that the adjustment operation is performed.

  According to the present invention, during the preset adjustment period in the kneading process, based on the position data in the kneading chamber of the rubber material acquired by the position sensor, by performing the adjusting operation for adjusting the rotor interval, the rubber The material can be smoothly fed between the rotors, and the rotating rotor can effectively apply a shearing force to the rubber material. As a result, the rubber material can be efficiently kneaded in a shorter time.

It is explanatory drawing which illustrates the kneading system of this invention by making a closed type kneader into a longitudinal cross-sectional view. It is explanatory drawing which illustrates the kneading machine of FIG. 1 in planar view. It is explanatory drawing which illustrates a pair of rotor of FIG. 1 by a top view. It is a graph which illustrates the phase data of a pair of rotors of FIG. It is explanatory drawing which illustrates the state which is kneading the rubber material between the rotors of FIG. It is explanatory drawing which illustrates the state which is kneading | mixing a rubber material between each rotor of FIG. 1, and the inner surface of a kneading chamber.

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

  In the kneading system of the rubber material of the present invention illustrated in FIGS. 1 to 3, 1 (hereinafter referred to as kneading system 1) kneads a rubber material R containing a raw rubber G and a compounding agent N. By this kneading step, an unvulcanized kneaded rubber RF having a predetermined quality (for example, target viscosity) in which the compounding agent N is uniformly dispersed in the raw rubber G is manufactured.

  As the raw material rubber G and the compounding agent N, appropriate materials are selected according to the type (characteristic) of the rubber material to be manufactured. As the raw material rubber G, 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 may be used alone or in combination of two or more. As the compounding agent N, silica and a silane coupling agent, a filler such as carbon black, and a non-vulcanizing compounding agent N such as zinc oxide and stearic acid are appropriately selected and used. Oil is also used as the compounding agent N.

  The kneading system 1 includes a closed kneading machine 2 (hereinafter referred to as kneading machine 2) and a control unit 12 that controls the operation of the kneading machine 2. The kneading machine 2 includes a kneading chamber 5 into which a rubber material R containing a raw rubber G and a compounding agent N is charged, a pair of rotors 3 placed inside the kneading chamber 5, and a rotor distance L between the pair of rotors 3. And a variable mechanism 8 for changing the.

  Each rotor 3 has a rotating shaft 4a arranged in parallel with each other, and a stirring blade 4b protrudingly provided on the outer peripheral surface of the rotating shaft 4a. In this embodiment, the so-called meshing type rotor 3 is arranged so that the outer peripheral surfaces of the rotors 3 mesh with each other. The specifications of the outer peripheral surface of each rotor 3 (shape of the outer peripheral surface, etc.) are appropriately set depending on the type of the rubber material R and the like. The alternate long and short dash line in FIG. 3 indicates the axis of each rotating shaft 4a. The distance between the axes is the rotor distance L.

  Each rotating shaft 4a is connected to the drive motor 3a via a variable mechanism 8. Each rotating shaft 4a is rotationally driven by the drive motor 3a. The rotary shafts 4a may be rotationally driven by the same single drive motor 3a. The control unit 12 controls the rotation drive and stop of the rotation shaft 4a, the rotation speed, and the like.

  A ram chamber 6a is connected to the upper end opening 5a of the kneading chamber 5 and extends upward. Inside the ram chamber 6a, a ram 6 that moves up and down to apply a pressure (ram pressure) to the raw rubber G (rubber material R) inside the kneading chamber 5 is arranged. By moving the ram 6 downward, the upper end opening 5a of the kneading chamber 5 can be closed.

  On the side surface of the ram chamber 6a, a rubber charging section 7a for charging the raw material rubber G and a compounding agent charging section 10 for charging the non-vulcanized compounding agent N from the hopper 9 are provided. The side surface of the kneading chamber 5 is provided with an oil feeding portion 7b, and the bottom surface is provided with an opening / closing discharge door 11.

  The rotor mechanism L has a variable structure by the variable mechanism 8. It is possible to adopt a structure in which only one rotor 3 moves toward and away from the other rotor 3 or a structure in which both rotors 3 move toward and away from each other. The operation of the variable mechanism 8 is controlled by the controller 12.

  A power meter 12a is attached to the control unit 12. The instantaneous power P required to drive the rotor 3 to rotate is sequentially detected by the power meter 12a, and the detection data is input to the controller 12. The control unit 12 calculates the integrated amount of electric power by integrating the instantaneous electric power, and can grasp the amount of electric power (the load acting on the rotor 3) required for the rotational driving of the rotor 3 in an arbitrary kneading period. The rotation speed (rotation speed) of the rotor 3 and the ram pressure are also input to the control unit 12, and the rotation speed of the rotor 3 and the ram pressure (the vertical movement of the ram 6) are controlled by the control unit 12.

  The kneading system 1 of this embodiment further includes a phase sensor 13 and a position sensor 14. The phase sensor 13 and the position sensor 14 are communicably connected to the control unit 12.

  The phase sensor 13 sequentially acquires the phase data Fd due to the rotation of the pair of rotors 3. The phase data Fd is data of the rotation angle (rotated position) of each rotor 3 illustrated in FIG. When each rotor 3 makes one rotation (360 ° rotation), the area S of the gap between the rotors 3 in top view changes. More specifically, this area S is an area in a top view sandwiched between the outer peripheral surfaces of the rotors 3 in the kneading chamber 5. In FIG. 3, this area S is illustrated by the shaded area.

  The phase data Fd acquired by the phase sensor 13 is sequentially input to the control unit 12. In this embodiment, as the phase sensor 13, an angle meter that detects the rotation angle of the pair of rotors 3 is used, and is attached to the drive motor 3a.

  This area S is repeated every one rotation of each rotor 3, as illustrated in FIG. In this embodiment, the area S has a maximum value Sx (maximum area) when each rotor 3 rotates 30 ° from a certain position, and has a minimum value Sn (minimum area) when the rotor 3 rotates 110 °. Such a variation of the area S is repeated every 1/2 rotation (180 ° rotation) of each rotor 3. The variation of the area S varies depending on the specifications (shape of the outer peripheral surface, etc.) of the outer peripheral surface of each rotor 3, and is not limited to the example illustrated in FIG. 4.

  Since the specifications (peripheral surface shape, etc.) of each rotor 3 are known, if the phase of each rotor 3 is known, the area S at any time can be grasped. Therefore, in this embodiment, the phase data Fd is sequentially input to the control unit 12, and the area S is sequentially calculated by the control unit 12 based on the input phase data Fd.

  The position sensor 14 acquires position data Pd of the rubber material R in the kneading chamber 5. The position data Pd is data indicating in which range and at what ratio the rubber material R (raw material rubber G) exists in the kneading chamber 5. That is, it is distribution data of the rubber material R (raw material rubber G) in the kneading chamber 5. A plurality of position sensors 14 are installed inside the kneading chamber 5.

  The position data Pd acquired by the position sensor 14 is sequentially input to the control unit 12. In this embodiment, a pressure sensor that contacts the rubber material R to detect pressure is used as the position sensor 14. The position sensors 14 are installed on both side surfaces of the kneading chamber 5 and on the back surface of the kneading chamber 5 which is an upper end portion and a lower end portion between the pair of rotors 3.

  By contacting the position sensor 14 installed in the kneading chamber 5 with the rubber material R (raw material G), it can be understood that the rubber material R (starting rubber G) exists at the installation position of the position sensor 14. . When a pressure sensor is used, the distribution state of the rubber material R (raw material G) in the kneading chamber 5 is sequentially calculated by the control unit 12 based on the magnitude of the detected pressure and the detection frequency (detection length). To be done.

  In this embodiment, the control unit 12 controls the variable mechanism 8 based on the phase data Fd acquired by the phase sensor 13 and the position data Pd acquired by the position sensor 14 during a preset adjustment period in the kneading process. The rotor spacing L is controlled and adjusted. Along with the adjustment of the rotor interval L, an adjusting operation for adjusting the area S to a desired size is performed, and a shearing force is effectively applied to the rubber material R (raw material G).

  Hereinafter, an example of a procedure of kneading the rubber material R by the kneading method of the rubber material of the present invention will be described.

  In the kneading step, a predetermined amount of one batch of rubber material R (raw material G, non-vulcanizing compounding agent N, oil, etc.) is charged into the kneading chamber 5 of the kneading machine 2 of FIG. The kneading rubber RF is manufactured by kneading under a predetermined kneading condition (for example, the rotation speed of the rotor 3, the ram pressure, the kneading time and the like are controlled) so as to obtain the target viscosity. The volume of the rubber material R charged is, for example, 50% to 70% of the volume of the kneading chamber 5.

  The kneading process includes, for example, the following charging step (S1), masticating step (S2), taking-in step (S3), and dispersing step (S4). In the charging step (S1), as illustrated in FIG. 1, while the ram 6 is held at the standby position at the upper end of the ram chamber 6a, a predetermined amount of the raw material rubber G is preset through the rubber charging unit 7a. It is thrown in 5.

  In the mastication step (S2), while the ram 6 is moved downward to the lower end of the ram chamber 6a, the rotor 3 is rotationally driven while the oil is introduced into the kneading chamber 5 through the oil introduction part 7b to rotate the raw material rubber G. Is meditated.

  In the taking-in step (S3), the ram 6 is moved to the standby position at the upper end of the ram chamber 6a, and a predetermined amount of a predetermined amount of the compounding agent N (filler or the like) is supplied from the hopper 9 to the compounding agent input unit 10. Is charged into the kneading chamber 5. Then, the rotor 3 is rotationally driven in a state where the ram 6 is moved downward to the lower end of the ram chamber 6a to knead the masticated raw material rubber G and the compounding agent N so that the compounding agent N becomes the raw material rubber G. It is captured.

  In the dispersion step (S4), the compounding agent N is dispersed so as to be uniform throughout the raw rubber G by further kneading. When the dispersing step (S4) ends and the kneading step of the rubber material R for one batch ends, the discharge door 11 is opened and the kneading rubber RF is discharged from the bottom surface of the kneading chamber 5. Thereafter, a similar kneading step is sequentially performed on a new rubber material R for one batch, and the rubber material R for a plurality of batches is continuously kneaded. The raw rubber G and the compounding agent N may be put into the kneading chamber 5 together for kneading, and the present invention can be applied to this case as well.

  It is possible to set all stages (S1 to S4) of the kneading process as the adjustment period during which the above-described adjustment operation is performed, but it is also possible to set one or more necessary stages. In the dispersion step (S4), since kneading is in progress, it is not necessary to give such a large shearing force to the rubber material R (raw material rubber G). Therefore, the stages (S1 to S3) excluding the dispersion stage (S4) can be set as the adjustment period for performing the above-described adjustment operation.

  In the adjustment period, the rubber material R is kneaded while performing an adjustment operation based on the phase data Fd and the position data Pd. This adjusting operation will be described in detail. When the rubber material R is unevenly distributed between the pair of rotors 3, the area S is adjusted so as to be relatively small, and the rubber material R is not between the pair of rotors 3. When the areas are unevenly distributed, the area S is adjusted to be relatively large.

  When the rubber material R is unevenly distributed between the pair of rotors 3, it means that the space between the pair of rotors 3 is substantially filled with the rubber material R (raw material rubber G), as illustrated in FIG. is there. In this embodiment, the rubber material R (raw material rubber G) is in contact with the position sensors 14 installed at the upper end portion and the lower end portion between the pair of rotors 3. When the rubber material R is unevenly distributed between the pair of rotors 3, the area S is relatively reduced to a desired size, so that the rubber material R (raw material A larger shearing force can be applied to the rubber G) by the pair of rotating rotors 3.

  When the rubber material R is unevenly distributed in a position other than between the pair of rotors 3, the rubber material R (raw material rubber G) is generally present between the pair of rotors 3 as illustrated in FIG. There is no state. In this embodiment, when the rubber material R (raw material rubber G) is not in contact with the position sensors 14 installed at the upper end and the lower end between the pair of rotors 3, it is installed on both side surfaces of the kneading chamber 5. This is when the rubber material R (raw material rubber G) is in contact with the position sensor 14 thus operated.

  When the rubber material R is unevenly distributed at a position other than between the pair of rotors 3, the area S is relatively increased to a desired size. Therefore, in this operation, since the rotor gap L is generally increased relatively, the gap between each rotor 3 and the inner surface of the kneading chamber 5 becomes small, and the rubber material R existing in this gap is reduced. A larger shearing force can be applied to the (raw rubber G) by the pair of rotating rotors 3.

  Further, in this operation, as illustrated in FIG. 6, the rotor interval L becomes relatively large before the rubber material R is fed between the pair of rotors 3. Therefore, in the masticating step (S2) to the dispersing step (S4), the rubber material R (raw material rubber G) to be kneaded while repeatedly moving inside the kneading chamber 5 is smoothly fed between the pair of rotors 3. You can In addition, in the charging step (S1), the raw material rubber G charged from the rubber charging port 7a can be smoothly fed between the pair of rotors 3 in which the rotor gap L is relatively large. That is, it is advantageous that the raw material rubber G can be quickly bited into each rotor 3.

  By performing the adjustment operation in this way, the rubber material R (raw material G) can be smoothly fed between the pair of rotors 3, and the pair of rotating rotors 3 changes the rubber material R (raw material G) into the rubber material R (raw material G). It becomes possible to effectively apply the shearing force. As a result, the rubber material R can be efficiently kneaded in a shorter time, which contributes to improving the productivity of the kneaded rubber RF having a predetermined quality.

  In the above embodiment, the adjustment operation is performed based on the phase data Fd and the position data Pd, but the phase data Fd may be omitted and the adjustment operation may be performed based on only the position data Pd. That is, as another embodiment, the rubber material R (raw material rubber G) is adjusted while the controller 12 controls the variable mechanism 8 based on the position data Pd to adjust the rotor gap L to a desired size. It is also possible to carry out kneading.

  Specifically, when the rubber material R is unevenly distributed between the pair of rotors 3, the rotor interval L is adjusted to be relatively small, and the rubber material R is located at a position other than between the pair of rotors 3. When unevenly distributed, the rotor spacing L is adjusted to be relatively large. In this embodiment, since the phase data Fd is not taken into consideration, there is a possibility that the above-mentioned area S will not become relatively small even if the rotor interval L is made relatively small. However, since the possibility thereof is extremely small, the rubber material R can be efficiently kneaded in a shorter time in a manner similar to the above-described embodiment, which contributes to the improvement of the productivity of the kneaded rubber RF having a predetermined quality.

  When the pair of rotors 3 is of the meshing type, the present invention is particularly useful because the area S varies relatively due to the rotation of the pair of rotors 3. However, the pair of rotors is of the non-meshing type (so-called tangential type). The present invention is useful even in the case of a rotor. The present invention can also be applied to the case where the vulcanized compounding agent N is kneaded with the rubber material R in which the raw rubber G is kneaded with the non-vulcanized compounding agent N.

1 Kneading System 2 Closed Kneading Machine 3 Rotor 4a Rotating Shaft 4b Stirring Blade 5 Kneading Chamber 5a Top Opening 6 Ram 6a Ram Chamber 7a Rubber Input 7b Oil Input 8 Variable Mechanism 9 Hopper 10 Compounding Agent Input 11 Discharge Door 12 Control Part 12a Power meter 13 Phase sensor 14 Position sensor G Raw rubber N Compounding agent R Rubber material RF Kneading rubber S Area of gap between a pair of rotors when viewed from above

Claims (7)

A rubber material containing a raw material rubber and a compounding agent, in a kneading method of a rubber material to be kneaded using a closed kneader having a variable rotor spacing of a pair of rotors placed inside the kneading chamber,
During a preset adjustment period in the kneading step, the rubber material is kneaded while performing an adjusting operation for adjusting the rotor interval based on position data of the rubber material in the kneading chamber. Kneading method for rubber materials.   When the rubber material is unevenly distributed between the pair of rotors, the adjusting operation is performed so as to relatively reduce the rotor gap, and the rubber material is located at a position other than between the pair of rotors. The method of kneading a rubber material according to claim 1, wherein an operation is performed so as to relatively increase the rotor interval when unevenly distributed.   When the adjusting operation is performed based on phase data due to rotation of the pair of rotors and the rubber material is unevenly distributed between the pair of rotors, the area of the gap between the pair of rotors in a top view. Is relatively small, and when the rubber material is unevenly distributed at a position other than between the pair of rotors, the area is relatively large. A method for kneading the rubber material as described.   The kneading step, a charging step of charging the raw material rubber into the kneading chamber, a mastication step of masticating the raw material rubber, and the compounding agent by kneading the masticated raw material rubber and the compounding agent To the raw material rubber, and a dispersing step of dispersing the compounding agent in the raw material rubber, except for the dispersing step, the charging step, the masticating step and the incorporating step are The method for kneading a rubber material according to claim 1, which is set as an adjustment period.   The kneading step, a charging step of charging the raw material rubber into the kneading chamber, a mastication step of masticating the raw material rubber, and the compounding agent by kneading the masticated raw material rubber and the compounding agent Of the compounding agent into the raw material rubber, and a dispersing step of dispersing the compounding agent into the raw material rubber, the charging step, the masticating step, the incorporating step and the dispersing step as the adjustment period. The method for kneading a rubber material according to claim 1, which is set. A hermetically sealed type having a kneading chamber into which a rubber material containing a raw rubber and a compounding agent is charged, a pair of rotors placed inside the kneading chamber, and a variable mechanism for varying the rotor distance between the pair of rotors. In a kneading system for a rubber material, which comprises a kneading machine and a control unit for controlling the operation of this closed type kneading machine,
A position sensor that acquires position data of the rubber material in the kneading chamber is provided, and in a preset adjustment period in a kneading process, based on the position data acquired by the position sensor, by the control unit. A kneading system for a rubber material, characterized in that an adjusting operation for adjusting the rotor spacing is performed by controlling the variable mechanism.   It has a phase sensor that acquires phase data due to rotation of the pair of rotors, and based on the phase data acquired by the phase sensor, the area of the gap in a top view between the pair of rotors is the adjusting operation. The kneading system for a rubber material according to claim 6, which is configured to be adjusted.

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