JP2015168181A - Temperature measurement method for rubber extruded object and temperature measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature measurement method for a rubber extruded object and a temperature measurement device therefor, which can measure an internal temperature of the rubber extruded object being extruded from an extruder and passing through a die, with high accuracy and without affecting a next process in a manufacturing line.SOLUTION: In a temperature measurement method for a rubber extruded object, a metal wire 2 with a wire diameter of 0.2 to 0.5 mm having a thermocouple 8 therein is fixed inside a die 4 which is installed in an extruder 9. The metal wire 2 is tensioned between a peripheral face 7a and a peripheral face 7a of an extrusion port 7 of the die 4. A non-vulcanized rubber extruded object R is extruded from the extrusion port 7. While the rubber extruded object R is being incised by the metal wire 2 temporarily, a temperature of the incised part is measured by the thermocouple 8 immediately after the incision takes place, before incised faces Rf of the rubber extruded object R are mutually joined.

Description

  The present invention relates to a temperature measurement method and a temperature measurement device for a rubber extrudate, and more specifically, can measure the internal temperature of a rubber extrudate extruded from an extruder and passing through a die with high accuracy, The present invention relates to a temperature measurement method and a temperature measurement device for a rubber extrudate that can be measured without affecting the next process of a production line.

  When manufacturing rubber products such as tires, there is an extrusion process in which unvulcanized rubber is extruded by an extruder. In such an extrusion process, the unvulcanized rubber is extruded from an extrusion port of a die attached to the extruder, thereby forming a rubber extrudate molded into a predetermined shape. Here, for example, when unvulcanized rubber compounded with silica is extruded, the internal temperature of the rubber extrudate has a great influence on the stability of the rubber extrudate, for example, the inside of the rubber extrudate foams due to a temperature rise due to plasticization. It is important to accurately grasp the internal temperature of the rubber extrudate because local deformation of the rubber extrudate generated when plasticized by the screw of the extruder appears in the internal temperature distribution of the rubber extrudate. .

  Various methods for measuring the internal temperature of the rubber extrudate have been proposed (see, for example, Patent Document 1). In the measuring method proposed in Patent Document 1, the surface temperature of the rubber extrudate is measured at at least two locations, and the internal temperature of the rubber extrudate is determined based on the measured value and the thickness of the rubber extrudate. However, this method does not actually measure the internal temperature of the rubber extrudate, but predicts it, so there is a limit to increasing the measurement accuracy.

  In the method of directly measuring the internal temperature by inserting a thermometer probe directly into a rubber extrudate immediately after extrusion, the probe temperature affects the measurement temperature. It is necessary to take measures such as heating up to the temperature. Alternatively, it is also conceivable that the rubber extrudate immediately after extrusion is cut with a cutting tool such as a blade and the cut surface is measured with an infrared thermometer or the like. However, since the cutting tool such as a blade has a large contact area with the rubber extrudate (the contact time is long), the temperature difference between the rubber extrudate and the cutting tool affects the measurement temperature, and the temperature of the cut surface changes. Therefore, there is a problem that the internal temperature of the rubber extrudate (the temperature of the cut surface) cannot be accurately measured. Further, in a production line using a rubber extrudate, there is a problem that the rubber extrudate cut by the cutting tool cannot be used in the next process as it is.

JP-A-11-151747

  The object of the present invention is to measure the internal temperature of a rubber extrudate extruded from an extruder and passing through a die with high accuracy and enable measurement without affecting the next process of the production line. An object of the present invention is to provide a temperature measurement method and a temperature measurement device for rubber extrudates.

  In order to achieve the above object, the method for measuring the temperature of a rubber extrudate according to the present invention fixes a metal wire having a wire diameter of 0.2 mm or more and 0.5 mm or less having a thermocouple inside a die installed in an extruder. Then, a tension is applied between the peripheral surface of the extrusion port of the die, an unvulcanized rubber extrudate is extruded from the extrusion port, and the rubber extrudate is temporarily cut by the metal wire. However, immediately after the incision and before the incised surfaces of the rubber extrudates are joined, the temperature of the incised portion is measured by the thermocouple.

  The rubber extrudate temperature measuring device of the present invention comprises a metal wire having a wire diameter of 0.2 mm or more and 0.5 mm or less that is stretched between the peripheral surface of the extrusion port of a die installed in an extruder. A fixing member for fixing and tensioning the metal wire inside the die, and a thermocouple provided in the metal wire, and a rubber extrudate extruded from the extrusion port is temporarily provided by the metal wire. After the incision, the temperature of the incised portion is measured by the thermocouple immediately before the incision surfaces of the rubber extrudates are joined.

  According to the present invention, a metal wire having a wire diameter of 0.2 mm or more and 0.5 mm or less is fixed inside a die installed in an extruder, and tension is applied between the peripheral surface of the extrusion port of the die. Since the rubber extrudate extruded from the extruder and passing through the die is temporarily cut by this metal wire, the contact area between the rubber extrudate and the metal wire becomes very small. Time is also very short. Since it is a thin metal wire, the temperature of the rubber extrudate hardly changes even when the rubber extrudate comes into contact. Thereby, the influence of the temperature of a metal wire can be minimized and the inside of the rubber extrudate immediately before extrusion can be exposed as a cut surface. And since the temperature of the incised part is measured by the thermocouple immediately after the incision and before the incised surfaces of the rubber extrudates are joined, measurement with high accuracy becomes possible.

  Further, since the rubber extrudate is temporarily cut through the die, the cut surfaces are immediately joined and integrated after passing through the die. Therefore, the temperature-measured rubber extrudate can be used as it is sent to the next step of the production line. That is, in the present invention, since the rubber extrudate is only temporarily cut, the internal temperature of the rubber extrudate can be measured without affecting the next process of the production line using the rubber extrudate.

It is explanatory drawing which illustrates the temperature measuring apparatus of the rubber extrudate of this invention by planar view. It is a top view which expands and illustrates the metal wire periphery of FIG. It is explanatory drawing which illustrates the structural member of dice | dies by a front view. It is explanatory drawing which illustrates the structural member of dice | dies by a side view. It is an enlarged view of a metal wire. 6A is a cross-sectional view taken along the line AA in FIG. 5, and FIG. 6B is a cross-sectional view taken along the line BB in FIG. It is explanatory drawing which shows the modification of a metal wire. It is explanatory drawing which illustrates the state in which a holding member is pressed by the pressure of a rubber extrudate by front sectional view of a die. It is a graph which shows the surface temperature and internal temperature of the rubber extrudate which were measured.

  Hereinafter, the method and apparatus for measuring the temperature of a rubber extrudate according to the present invention will be described based on the embodiments shown in the drawings.

  In the embodiment of the temperature measurement device 1 for rubber extrudates of the present invention illustrated in FIGS. 1 to 4, a metal wire 2 having a wire diameter of 0.2 mm or more and 0.5 mm or less and the metal wire 2 are attached to an extruder 9. A fixing member 3 that is fixed and tensioned inside the die 4 and a thermocouple 8 provided in the metal wire 2 are provided. The extruder 9 is a known single-screw or twin-screw extruder, and has a screw. A take-up conveyor 10 is disposed in front of the extrusion port 7 formed in the die 4. In FIG. 2, the metal wire 2 is exaggerated and greatly illustrated for easy understanding.

  The fixing member 3 of this embodiment is a pair of fixing members 3 that hold the metal wires 2 at spaced positions. Each fixing member 3 has a portion formed in a wedge shape, and has a structure in which two members are integrated by a connecting material such as a screw 3a. And the fixing member 3 hold | maintains the metal wire 2 by pinching and connecting the metal wire 2 on the mutually opposing surface of two members. The fixing member 3 of this embodiment has a form in which two wedge shapes are joined to each other on the thin side in a front view.

  The die 4 is composed of two divided bodies 4A and 4B. One divided body 4A (large divided body 4A) is larger in size than the other divided body 4B (small divided body 4B). The small divided body 4B is fitted and attached to the mounting recess 5 formed on the front surface of the large divided body 4A, so that both are integrated. An extrusion port 7 having the same size and shape is formed in each of the divided bodies 4A and 4B.

  Two fitting portions 6 that are further recessed than the attachment recess 5 are formed in the attachment recess 5 of the large divided body 4A. Each fitting portion 6 is formed at a position corresponding to the upper peripheral surface 7 a and the lower peripheral surface 7 a of the extrusion port 7. Each fixing member 3 is fitted and attached to a fitting portion 6 formed on the die 4. The fitting portion 6 has a shape such that two wedge shapes are joined to each other on the thin side when viewed from the front, and has a shape corresponding to the fixing member 3. Each fixing member 3 is detachable with respect to the die 4 (fitting portion 6).

  By fitting the pair of fixing members 3 holding the metal wire 2 into the corresponding fitting portions 6, the metal wire 2 is fixed inside the die 4. Thereby, the metal wire 2 is tensioned so as to cut the extrusion port 7 vertically between the peripheral surface 7 a and the peripheral surface 7 a of the extrusion port 7. The fixing member 3 is not limited to the structure exemplified in the embodiment, and any metal member may be used as long as the metal wire 2 is fixed inside the die 4 and is tensioned between the peripheral surface 7a and the peripheral surface 7a of the extrusion port 7. Further, the metal wire 2 can be tensioned so as to cross the extrusion port 7.

  As for the shape of the extrusion port 7, the width direction dimension is generally larger than the thickness direction dimension. In this embodiment, the metal wire 2 extends in the thickness direction of the extrusion port 7 (vertical direction in FIG. 3) and is tensioned. As the metal wire 2, for example, a metal wire configured by twisting a plurality of metal filaments 2 a as exemplified in FIGS. 5 and 6 is used.

  As illustrated in FIGS. 5 and 6, the thermocouple 8 includes a temperature detection unit 8 a and a lead wire 8 b extending from the temperature detection unit 8 a, and is provided in the metal wire 2 having a twisted structure. In this embodiment, the metal wire 2 is formed by twisting a plurality of filaments 2a with the thermocouple 8 (temperature detection unit 8a) as a core. The lead wire 8 b extends from the middle position in the longitudinal direction of the metal wire 2 so as to protrude to the outside of the metal wire 2. The extended lead wire 8 b is connected to the data processor 11. Note that a cylindrical metal wire 2 may be used and a thermocouple 8 may be inserted into the metal wire 2.

  Of the outer peripheral surface of the metal wire 2, a portion at a position corresponding to the fixing member 3 and the die 4 is covered with a film-like heat insulating material 2 b, and most of a portion at a position corresponding to the extrusion port 7 is covered with the heat insulating material 2 b. Not covered. That is, the outer peripheral surface of the metal wire 2 is not in direct contact with the fixing member 3 and the die 4, and the heat insulating material 2b is interposed. As the heat insulating material 2b, for example, a resin having a thermal conductivity of 0.17 W / (m · K) or less at 20 ° C. is used. The thickness of the heat insulating material 2b is 0.1 mm or less, for example, and is very small compared to the wire diameter of the metal wire 2.

  Next, the procedure of the measurement method of the present invention for measuring the internal temperature of the rubber extrudate R extruded from the extruder 9 and passing through the die 4 will be described.

  First, a predetermined amount of unvulcanized rubber and compounding agent are charged into the extruder 9. These are mixed and kneaded by an extruder 9. The mixed and kneaded unvulcanized rubber is softened to some extent (plasticized), shaped into the shape of the extrusion port 7 from the extrusion port 7, and extruded as a sheet of unvulcanized rubber extrudate R. Since the metal wire 2 is tensioned between the peripheral surface 7 a and the peripheral surface 7 a of the extrusion port 7, the central portion in the width direction of the rubber extrudate R is incised left and right by the metal wire 2.

  The metal wire 2 has a thin diameter of 0.2 mm or more and 0.5 mm or less while the thermocouple 8 is installed, so that it contacts the rubber extrudate R when the rubber extrudate R extruded from the extruder 9 is cut. The area becomes very small, and accordingly, the contact time becomes very short. Therefore, even if the rubber extrudate R contacts the metal wire 2, the temperature of the rubber extrudate R hardly changes. Moreover, the metal wire 2 with a small diameter immediately becomes the same temperature as the temperature of the extruded rubber extrudate 2.

  The rubber extrudate R incised by the metal wire 2 is united by natural joining of the incised surfaces Rf immediately after being incised in the extruded flow. That is, the cut surfaces Rf of the rubber extrudate R are automatically joined together by the swell of unvulcanized rubber cut by the metal wire 2 (property to spread).

  Here, the thermocouple 8 (temperature detection unit 8a) installed in the metal wire 2 is an incised part immediately after incision of the rubber extrudate R and before the incision surfaces Rf of the rubber extrudate R are joined ( The temperature of the cut surface Rf) is measured. The temperature data measured by the temperature detector 8a is input to the data processor 11 through the lead wire 8b. The temperature of the cut surface Rf of the rubber extrudate R immediately after the incision is the internal temperature of the rubber extrudate R passing through the die 4 and can be regarded as being substantially equal to the internal temperature of the rubber extrudate R immediately after the extrusion. Since the outer peripheral surface of the metal wire 2 is covered with the heat insulating material 2b and is not in direct contact with the fixing member 3 and the die 4, the heat of the fixing member 3 and the die 4 transmitted to the metal wire 2 is slight. Therefore, the temperature detector 8a can accurately measure the internal temperature of the rubber extrudate R in real time by eliminating the influence of the temperature of the fixing member 3 and the die 4.

  In this way, by measuring the temperature of the cut surface Rf of the rubber extrudate R with the thermocouple 8 immediately after the cut, the temperature of the cut surface Rf can be suppressed from being affected by the external environment or the like. Therefore, according to the present invention, it is possible to measure the internal temperature of the rubber extrudate R with higher accuracy than before. Since the temperature measuring device 1 of the present invention can be applied to the existing extruder 9, it has high versatility.

  After the rubber extrudate R is temporarily incised by the metal wire 2, the incision surfaces Rf are extinguished when the incision surfaces Rf are joined together, and are conveyed to the next process by the take-up conveyor 10. Therefore, the temperature-measured rubber extrudate R can be used as it is in the next process of the production line. In particular, in the present invention, since the rubber extrudate R passing through the die 4 is only temporarily cut, the internal temperature of the rubber extrudate R is not affected without affecting the next process of the production line using the rubber extrudate R. Can be measured.

  Although the thermocouple 8 (temperature detection part 8a) is installed in the metal wire 2 illustrated in FIG. 5 without being exposed to the outside, the temperature detection part 8a is provided outside the metal wire 2 as illustrated in FIG. It can also be set in an exposed state. In the metal wire 2 illustrated in FIG. 7, the filaments 2a are twisted with a gap. Due to this twisted structure, the temperature detector 8a is exposed to the outside of the metal wire 2 from the gap between the filaments 2a. When the metal wire 2 having this structure is used, the temperature detection portion 8a can be brought into direct contact with the rubber extrudate R, which is more advantageous for improving measurement accuracy.

  In addition, when the wire diameter of the metal wire 2 is less than 0.2 mm, the metal wire 2 is easily cut by being pressed by the rubber extrudate 2, and the deflection of the metal wire 2 when pressed by the rubber extrudate R is increased. On the other hand, when the wire diameter of the metal wire 2 exceeds 0.5 mm, the contact area with the rubber extrudate R increases, and accordingly, the contact time also increases. Thereby, the temperature of the metal wire 2 affects the temperature of the cut surface Rf, which is disadvantageous for accurately measuring the internal temperature of the rubber extrudate R.

  Since the metal wire 2 continues to be pressed by the rubber extrudate R, the elongation may occur or the tension may be loosened. In such a case, the rubber extrudate R cannot be stably incised at a predetermined position. However, in this embodiment, each of the pair of fixing members 3 has a wedge shape that narrows from the peripheral surface 7a of the extrusion port 7 toward the outer peripheral surface 4a of the die 4 in a state of being fitted to the fitting portion 6. Yes. Therefore, as illustrated in FIG. 8, each fixing member 3 is pressed toward the outer peripheral surface 4 a side of the die 4 by the pressure of the rubber extrudate R passing through the extrusion port 7. This pressing increases the fixing strength of each fixing member 3 with respect to the fitting portion 6 and increases the tension tension of the metal wire 2. Therefore, the metal wire 2 can be strongly tensioned automatically by extruding the rubber extrudate R.

  When the rubber extrudate R is extruded at an extrusion speed of less than 10 cm / sec, the load on the metal wire 2 is not so large, but when it is extruded at an extrusion speed of 10 cm / sec or more, the load on the metal wire 2 is excessive. become. Therefore, when the extrusion speed of the rubber extrudate R is set to 10 cm / sec or more, it is preferable that the metal wire 2 is stretched in the thickness direction of the extrusion port 7 to be tensioned as illustrated in FIG. In addition, although the tension | tensile_strength direction of the metal wire 2 can also be orthogonally crossed (crossing angle 90 degrees) with respect to the width direction of the extrusion port 7, it inclines to some extent with respect to the width direction of the extrusion port 7, as illustrated in FIG. When intersecting (for example, intersecting angle of 45 ° to 80 °), it becomes easy to join the cut surfaces Rf that are temporarily cut by the metal wire 2.

  The internal temperature data of the rubber extrudate R obtained by the present invention can be used effectively when determining the optimum condition setting when the rubber extrudate R is extruded by the extruder 9. Further, since the temperature distribution inside the rubber extrudate R can be grasped, the high temperature portion of the rubber extrudate R can be cooled more intensively and used to prevent burns and to stabilize the member. Burns can be prevented and the yield of the rubber extrudate R can be improved, which contributes to energy saving and is also an ecological measure.

  When an unvulcanized rubber extrudate with the same specifications (width: about 180 mm, thickness: about 15 mm) was extruded under the same conditions using the same extruder, the surface temperature of the rubber extrudate immediately after extrusion was measured with a thermography device (comparison) Example) In addition, the temperature of the cut surface when a metal wire temporarily cuts the position of about 1/4 of the width dimension from the one end in the width direction of the rubber extrudate passing through the die to the left and right with the metal wire. It measured with the thermocouple installed internally (Example). For measuring the temperature of the cut surface, using the same equipment as the temperature measuring device illustrated in FIGS. 1 to 6, a metal wire having a wire diameter of 0.4 mm is inserted between the peripheral surface of the extrusion port. I was nervous to run through. The measurement results are schematically shown in FIG. A broken line indicates a comparative example, and a solid line indicates an example.

  From the results of FIG. 9, it can be seen that the measurement temperature of the example is generally higher than that of the comparative example, and the internal temperature of the rubber extrudate immediately after extrusion can be grasped with high accuracy. Moreover, in the Example, it joined immediately after the cut surface of the rubber extrudate cut | disconnected with the metal wire passed the die | dye.

DESCRIPTION OF SYMBOLS 1 Temperature measuring device 2 Metal wire 2a Filament 2b Heat insulating material 3 Fixing member 4 Dies 4A, 4B Divided body 4a Outer peripheral surface 5 Mounting recessed part 6 Fitting part 7 Extrusion port 7a Peripheral surface 8 Thermocouple 8a Temperature detection part 8b Lead wire 9 Extrusion Machine 10 Take-up conveyor 11 Data processing part R Rubber extrudate Rf Cut surface

Claims (12)

  A metal wire having a wire diameter of 0.2 mm or more and 0.5 mm or less in which a thermocouple is installed is fixed inside the die installed in the extruder, and between the peripheral surface of the extrusion port of this die. Tensioning, extruding an unvulcanized rubber extrudate from the extrusion port, and temporarily cutting the rubber extrudate with the metal wire, immediately before the cut surfaces of the rubber extrudates are joined together A method for measuring a temperature of a rubber extrudate, wherein the temperature of the incised portion is measured by the thermocouple.   The method for measuring a temperature of a rubber extrudate according to claim 1, wherein the temperature detection part of the thermocouple is set in a state of being exposed to the outside of the metal wire.   The method for measuring a temperature of a rubber extrudate according to claim 1 or 2, wherein the metal wire is composed of a plurality of filaments, and the filaments are twisted with the thermocouple as a core.   The metal wire is held between a peripheral surface of the extrusion port by holding the metal wire by a pair of fixing members and fitting the fixing members into a fitting portion formed on the die. The temperature measurement method of the rubber extrudate according to any one of claims 1 to 3.   A rubber extrudate that has a wedge shape that narrows from the peripheral surface of the extrusion port toward the outer peripheral surface of the die when the pair of fixing members are fitted to the fitting portion, and passes through the extrusion port. The rubber extrudate according to claim 4, wherein the fixing member is pressed toward the outer peripheral surface side of the die by the pressure of the die to increase the fixing strength with respect to the fitting portion fitted and the tension tension of the metal wire. Temperature measurement method.   The method for measuring a temperature of a rubber extrudate according to any one of claims 1 to 5, wherein the metal wire is stretched and stretched in a thickness direction of the extrusion port, and the rubber extrudate is extruded at an extrusion speed of 10 cm / sec or more. .   A metal wire having a wire diameter of 0.2 mm or more and 0.5 mm or less that is stretched between the peripheral surfaces of the extrusion ports of the die installed in the extruder, and the metal wire is fixed inside the die. The rubber extrudate extruded from the extrusion port is temporarily incised by the metal wire, and immediately after the incision, the rubber extrudate of the rubber extrudate is provided. The rubber extrudate temperature measuring device is configured to measure the temperature of the incised portion with the thermocouple before the cut surfaces are joined to each other.   The temperature measurement device for a rubber extrudate according to claim 7, wherein the temperature detection unit of the thermocouple is set in a state of being exposed to the outside of the metal wire.   The temperature measurement device for a rubber extrudate according to claim 7 or 8, wherein the metal wire is composed of a plurality of filaments, and the filaments have a twisted structure in which the thermocouple is used as a core.   The fixing member is composed of a pair of fixing members that hold the metal wire, and a fitting portion that fits the pair of fixing members is formed on the die, and the pair of fixing members are fitted to the fitting portion. The apparatus for measuring a temperature of a rubber extrudate according to any one of claims 7 to 9, wherein the metal wire is tensioned between a peripheral surface and a peripheral surface of the extrusion port.   A rubber extrudate that has a wedge shape that narrows from the peripheral surface of the extrusion port toward the outer peripheral surface of the die when the pair of fixing members are fitted to the fitting portion, and passes through the extrusion port. The apparatus for measuring a temperature of a rubber extrudate according to claim 10, wherein the pressure is pressed toward the outer peripheral surface of the die.   The temperature measurement of the rubber extrudate according to any one of claims 7 to 11, wherein the metal wire extends in the thickness direction of the extrusion port and is tensioned, and the extrusion speed of the rubber extrudate is set to 10 cm / sec or more. apparatus.

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