JP2016043660A - Method for supplying rubber material to extruder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for supplying a rubber material to an extruder, by which variation in a final extruded article and a final product can be suppressed by uniformizing supply amount of the rubber material to the extruder thereby maintaining a rubber width or a gauge of an extruded article constant.SOLUTION: The method for supplying a rubber material to an extruder is provided that has a measurement step of measuring mass of the rubber material supplied to the extruder with a mass measurement device and an adjustment step of adjusting the supplied amount of the rubber material based on the result of the measurement step.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for supplying a rubber material to an extruder.

  Conventionally, the rubber material is supplied to the extruder by feeding the rubber material R heated by the feed roll 1 to the hopper port 31 of the extruder 3 by the conveyor 2 as shown in FIG. Etc. are done.

  Since the extrudate extruded by the extrusion molding machine 3 is then processed into a final product tire through processes such as cutting, pasting with other members, and vulcanization, the rubber width and gauge (thickness) of the extrudate are reduced. The final product quality will be greatly affected. Therefore, it is very important in the manufacture of rubber products to keep the quality of the extrudate rubber width, gauge, etc. constant as intended.

  In the conventional rubber material supply method to the extrusion machine shown in FIG. 2, the rubber width and gauge supplied to the extrusion machine and the conveyance speed (feed roll rotation speed and conveyor speed) are made constant to perform extrusion molding. It has been practiced to stabilize the mass per unit length of the extrudate extruded from the extruder 3 while keeping the amount of rubber supplied to the machine 3 constant. However, due to variations in the physical properties of the rubber used and the adhesion of the rubber to the feed roll, the rubber material to be supplied changes due to swelling and elongation, and the supply amount is not completely constant. It is controlled to adjust the speed of the conveyor so that the mass per unit length of the extrudate becomes a target value. However, it is not easy to completely eliminate variations in the final extrudate and the final product, and further improvements are required.

  In Patent Document 1, the mass of a rubber material to be fed into an extrusion molding machine is measured, and the extrudate is made constant by controlling the rotation speed of a screw and the feed roll of the extrusion molding machine based on the measured value. Although the feed extruder and the extrusion method using the extruder are described, since the heat generation of the rubber material changes when the screw rotation speed of the extruder is changed, the progress of vulcanization and extrusion There is a problem that the shape of the object changes.

JP 2013-107246 A

  The present invention makes it possible to keep the rubber width and gauge of the extrudate from the extruder constant and to suppress variations in the final extrudate and the final product by making the supply amount of the rubber material to the extruder constant. It is an object of the present invention to provide a method for supplying a rubber material to an extrusion molding machine.

  The present invention relates to an extruder having a measuring step of measuring the mass of a rubber material supplied to the extruder by a mass measuring device, and an adjusting step of adjusting the supply amount of the rubber material based on the result of the measuring step. The present invention relates to a method for supplying a rubber material.

  The mass measuring device is provided in a conveyance path to a rubber material extrusion molding machine, and has a heating step of heating the rubber material with a feed roll before the measuring step, and the adjusting step is a measuring step. It is preferable that it is an adjustment process in which the mass per unit length of the rubber material supplied to the extruder is adjusted to be constant by adjusting the rotational speed of the feed roll based on the result.

  The adjustment of the rotation number of the feed roll is preferably an adjustment based on the difference between the mass measured by the mass measuring device and the target mass.

  The rubber material supply method to the extrusion molding machine of the present invention can make the supply amount of the rubber material constant to the extrusion molding machine, keep the rubber width and gauge of the extrudate from the extrusion molding machine constant, Variations in the final extrudate and final product can be suppressed.

It is a schematic diagram explaining the supply method of the rubber material to the extrusion molding machine which is one embodiment of this invention. It is a schematic diagram which shows the supply method of the rubber material to the conventional extruder.

  Hereinafter, although the supply method of the rubber material to the extruder of this invention is demonstrated, referring an accompanying drawing, it is not limited to this embodiment.

  FIG. 1 is a schematic view showing a method of supplying a rubber material to an extruder which is an embodiment of the present invention. This supply method includes a heating process in which the kneaded rubber material R is heated by the feed roll 1, a conveying process in which the heated rubber material R is conveyed to the extruder 3 by the conveyors 2a and 2b, the conveyor 2a and the conveyor 2b, Including a measuring step of measuring the mass of the rubber material by the mass measuring device 4 installed between the two, and further including an adjusting step of adjusting the supply amount of the rubber material based on the mass of the rubber material R measured in the measuring step It is a supply method.

  The measuring step is a step of measuring the mass of the rubber material R on the mass measuring device 4 by the mass measuring device 4 installed between the conveyors 2a and 2b and outputting the measurement result to the control device 5 or the like. . In addition, although the control apparatus 5 is shown as an independent apparatus in FIG. 1, you may provide the control apparatus 5 in the inside of the mass measurement apparatus 4, the inside of another structure, etc. Further, the mass may be measured continuously, or may be measured every predetermined time such as once every 5 seconds.

  The mass measuring device is not particularly limited, and a conventionally used measuring device can be used. In particular, the measuring device with a roller as shown in FIG. 1 can be transported toward the extrusion molding machine 3 together with the mass measurement of the rubber material R, and the mass of the rubber material R without stopping the transport of the rubber material R. Is preferable because it can be measured. The length of the measuring device with a roller is preferably 0.5 to 2.0 m, and more preferably 1.0 m.

  The adjustment step adjusts the supply amount of the rubber material to the extrusion molding machine 3 based on the mass measurement result of the rubber material R output from the mass measurement device 4 to the control device 5, thereby adjusting the rubber material R to be supplied. This is a step of making the mass per unit length constant. The mass measurement result measured by the mass measuring device 4 evaluates the variation of the rubber material R supplied to the extrusion molding machine 3, and the supplied rubber is adjusted by adjusting the supply amount based on the measurement result. The mass per unit length of the material R can be made constant. And by making the mass per unit length of the rubber material R supplied to the extrusion molding machine 3 uniform, the rubber material R in the extrusion molding machine 3 becomes uniform, so the rubber width and gauge of the extrudate are constant. Thus, variations in the final extrudate and the final product can be suppressed.

Adjustment of the amount of rubber material supplied to the extrusion molding machine may be performed by adjusting the number of rotations of the feed roll 1, or by adjusting the speeds of the conveyors 2a and 2b. These methods may be used in combination. The adjustment of these supply amounts can be adjusted based on the difference between the mass measured by the mass measuring device and the target mass. For example, the changed speed D ′ is calculated by the following equation (1), The feed roll and / or conveyor can be adjusted to speed D ′.
Formula (1): D ′ = D + (BA) / A × D
(Where D is the current speed, A is the target mass, B is the measured mass, and D ′ is the speed after the change)

  The feed roll 1 in the heating step is a conventional feed roll in that the kneaded rubber material R is heated, but a signal based on the mass of the rubber material R measured by the mass measuring device 4 is sent from the control device 5. The number of rotations of the feed roll can be adjusted according to the received signal.

  The conveyors 2a and 2b in the conveying process are conventional conveyors in that the heated rubber material R is conveyed to the extrusion molding machine 3, but a signal based on the mass of the rubber material R measured by the mass measuring device 4 is used. Is received from the control apparatus 5, and the speed of each conveyor can be adjusted according to this signal.

  The extrusion machine 3 includes a cylindrical cylinder, a screw rotatably accommodated in the cylinder, a hopper provided with a hopper port 31 connected to the upstream end side of the cylinder, and a vulcanization end of the cylinder. And an extrusion head connected to the side. The rubber material R supplied from the hopper port 31 is pushed forward while being kneaded in the cylinder when the screw is driven to rotate, and is pushed out from the extrusion port of the extrusion head. Extrudates with rubber width and gauge according to the shape of the extrusion port can be obtained.

  According to the rubber material supply method to the extrusion molding machine of the present invention, the supply amount of the rubber material to be supplied to the extrusion molding machine is adjusted based on the mass of the rubber material R measured by the mass measuring device. The rubber width and gauge of the extrudate from the extruder can be kept constant, and variations in the final extrudate and the final product can be suppressed. Furthermore, according to the present invention, since the extrudate can be made constant without controlling the screw rotation speed of the molding extruder, changes in the heat generation of the rubber material due to changes in the screw rotation speed of the extruder can be prevented. Further, variation in the final extrudate and the final product due to the progress of vulcanization and the change in the shape of the extrudate can be suppressed.

  The present invention will be described based on examples, but the present invention is not limited to the examples.

Example 1
As shown in FIG. 1, a rubber material supply machine to an extrusion machine in which a mass measuring device of 1 m is installed between conveyors that convey the rubber material heated by a feed roll to the extrusion machine, and an extrusion machine (φ200 × The rubber material was extruded into a tread shape using a φ150 × φ120 triple box). The feed roll rotation speed and the conveyor speed were adjusted so that the mass of the rubber material became the target value. Mass measurement by the mass measuring apparatus is performed at intervals of once every 5 seconds, the average mass of the measured mass for 6 times is B, the target weight is A, the current speed is D, and the speed after change is D ' D ′ was calculated from the equation (1), and the feed roll rotation speed and the conveyor speed were adjusted.
Formula (1): D ′ = D + (BA) / A × D

Comparative Example 1
The rubber material was supplied to an extrusion molding machine that does not have a mass measuring device, and was adjusted to a fixed speed without adjusting the feed roll rotation speed and conveyor speed. An extrusion process was performed.

Evaluation Method The mass per unit length of the tread-shaped extrudates obtained in the extrusion process of Example 1 and Comparative Example 1 was measured, the coefficient of variation (CV value) was calculated, and the degree of variation was evaluated. Moreover, CV value was calculated about the tread shape extrudate of each 10 lots, and the average value was calculated. The results are shown in Table 1.

  From the results shown in Table 1, according to the method for supplying rubber material to the extruder of the present invention, the amount of rubber material supplied to the extruder becomes constant compared to the comparative example, and the extrudate from the extruder It can be seen that the rubber width and gauge can be kept constant, and variations in the final extrudate and final product can be suppressed.

DESCRIPTION OF SYMBOLS 1 Feed roll 2a, 2b Conveyor 3 Extruder 31 Hopper port 4 Mass measuring apparatus 5 Control apparatus R Rubber material

Claims (3)

A measurement step of measuring the mass of the rubber material supplied to the extrusion molding machine by a mass measuring device, and an adjustment step of adjusting the supply amount of the rubber material based on the result of the measurement step;
A method for supplying a rubber material to an extrusion molding machine. The mass measuring device is provided in a conveyance path to an extruder for rubber material,
Having a heating step of heating the rubber material by a feed roll before the measurement step;
2. The adjustment step is an adjustment step of adjusting a mass per unit length of a rubber material supplied to an extruder by adjusting a rotation number of a feed roll based on a result of a measurement step. A method for supplying a rubber material to the extrusion molding machine. The method for supplying a rubber material to an extrusion molding machine according to claim 2, wherein the adjustment of the rotational speed of the feed roll is an adjustment based on a difference between a mass measured by a mass measuring device and a target mass.

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