JP2018048050A - Manufacturing method and manufacturing device of optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress temperature fluctuation of a resin which flows in a pipeline during manufacturing an optical fiber when a resin is applied to a glass fiber or a coating fiber.SOLUTION: There is provide a manufacturing method of an optical fiber G2 including a resin application process for supplying a resin 6 to a resin application part 5 via a pipeline 12. passing a glass fiber G1 or a covering fiber through the resin application part 5 and applying the resin 6 to outer periphery of the glass fiber G1 or the coating fiber through, in which a temperature of the resin application part 5 is set constant even when a fluid 5b at a constant temperature around the resin application part 5 and a heating part 13 arranged on at least a part of outer periphery of the pipeline 12 is controlled so that a resin temperature in the pipeline 12 is a target temperature.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an optical fiber manufacturing method and manufacturing apparatus.

  In the production of optical fiber, resin is supplied to the die through a pipe, and the glass fiber is passed through this die, so that the resin is applied to the outer periphery of the glass fiber, and this resin is cured to produce a coated optical fiber. And a manufacturing apparatus for the same are known (for example, Patent Documents 1 and 2).

Japanese Utility Model Publication No. 4-21527 Japanese Patent Laid-Open No. 61-14155

  The viscosity of the resin applied to the glass fiber varies depending on the temperature. When the viscosity changes, the coating conditions change and affect the coating formation of the optical fiber. For example, when the resin temperature increases, the coating diameter varies, such as a decrease in viscosity and a decrease in the coating diameter of the optical fiber. Moreover, uneven thickness may occur in the coating due to fluctuations in the resin temperature. For this reason, if the resin temperature fluctuates during the production of the optical fiber, the coating diameter may be out of the standard range.

In order to suppress fluctuations in the coating diameter and uneven thickness of the optical fiber, it is necessary to set the resin temperature in the dice (resin coating portion) to a certain target temperature where the coating diameter is within the standard range.
Therefore, as a conventional method for keeping the resin temperature constant, for example, a method described in Patent Document 1 is a method for keeping the temperature of a pipe constant by flowing hot water outside the pipe that supplies the resin to the die. For example, there is a method of keeping the temperature of the pipe constant by flowing hot water outside the pipe for supplying the resin to the die holder.
However, the conventional method as described above is a method of keeping the temperature of the pipe and the die holder constant, and it is not possible to suppress the temperature fluctuation of the resin flowing through the pipe at the time of manufacturing the optical fiber. There were cases where fluctuations and uneven thickness occurred.

  Therefore, an object of the present invention is to provide an optical fiber manufacturing method and manufacturing apparatus capable of suppressing temperature fluctuations of the resin applied at the time of manufacturing the optical fiber when the resin is applied to the glass fiber or the coated fiber.

In the optical fiber manufacturing method according to one aspect of the present invention, a resin is supplied to a resin coating part via a pipe, and a glass fiber or a coated fiber is passed through the resin coating part to the outer periphery of the glass fiber or the coated fiber. An optical fiber manufacturing method including a resin coating step of coating the resin,
In the resin application step,
A constant temperature fluid is allowed to flow around the resin application part to keep the temperature of the resin application part constant,
A heating unit provided on the outer periphery of at least a part of the pipe is controlled so that the resin temperature in the pipe becomes a target temperature.

  ADVANTAGE OF THE INVENTION According to this invention, when apply | coating resin to glass fiber or a covering fiber, the temperature fluctuation | variation of the resin apply | coated at the time of optical fiber manufacture can be suppressed.

It is a schematic block diagram of the apparatus which forms a coating | coated to the drawn glass fiber as an example of the manufacturing apparatus of an optical fiber. It is a graph which shows the relationship between resin temperature and resin viscosity. It is a graph which shows the relationship between resin temperature and a coating diameter. It is a figure which shows the resin supply part in the manufacturing apparatus of the optical fiber which concerns on embodiment. It is a block diagram of a resin tank.

[Description of Embodiment of the Present Invention]
First, embodiments of the present invention will be listed and described.
An optical fiber manufacturing method according to an embodiment of the present invention includes:
(1) Light including a resin application step of supplying a resin to a resin application part via a pipe and passing the glass fiber or the coated fiber through the resin application part to apply the resin to the outer periphery of the glass fiber or the coated fiber A fiber manufacturing method comprising:
In the resin application step,
A constant temperature fluid is allowed to flow around the resin application part to keep the temperature of the resin application part constant,
A heating unit provided on the outer periphery of at least a part of the pipe is controlled so that the resin temperature in the pipe becomes a target temperature.

  According to the above-described optical fiber manufacturing method, the heating unit provided on the outer periphery of at least a part of the pipe is controlled so that the resin temperature becomes the target temperature. Thereby, even if temperature fluctuation occurs in the resin flowing through the pipe at the time of manufacturing the optical fiber, the fluctuation of the resin temperature flowing to the resin coating portion can be suppressed and kept at a constant resin temperature. And since the fluid of fixed temperature is poured around the resin application part and the temperature of the resin application part is made constant, resin by which temperature was kept constant can be apply | coated to glass fiber or a coated fiber. Therefore, fluctuations in the coating diameter of the manufactured optical fiber and occurrence of uneven thickness can be suppressed.

(2) The resin temperature is measured in the pipe, and the heating unit is controlled so that the measured temperature becomes the target temperature.
Since the resin temperature is measured in the pipe, the resin temperature in the pipe can be grasped more accurately.

(3) The resin temperature is measured in the pipe between the pipe in the portion where the heating unit is provided and the resin application unit.
If there is a difference between the resin temperature supplied into the pipe and the pipe temperature of the part where the heating unit is provided, the pipe temperature heated by the heating unit and the resin temperature gradually increase while the resin moves. it's coming. For this reason, by measuring the resin temperature in the pipe between the pipe where the heating part is provided and the resin application part (for example, the joint part of the pipe), the resin temperature at the part closer to the resin application part Can be controlled to a target temperature.

(4) The resin tank is heated so that the temperature of the resin tank containing the resin supplied to the pipe is constant.
Since the resin tank is heated so that the temperature of the resin tank becomes constant, the resin temperature supplied into the pipe is stabilized, so that the fluctuation of the resin temperature can be more reliably suppressed.

(5) The temperature setting value of the heating part is set higher than the temperature of the resin application part.
Since the temperature setting value of the heating part is set higher than the temperature of the resin application part, even if the resin temperature decreases after passing through the part where the heating part is provided, the temperature can be kept close to the temperature of the resin application part. it can.

(6) The heating unit is controlled in consideration of a decrease in the resin temperature until the resin in the pipe where the heating unit is provided is supplied into the resin application unit.
Since the heating unit is controlled in consideration of the decrease in the resin temperature until the resin in the pipe of the part provided with the heating unit is supplied into the resin coating unit, the resin temperature entering the resin coating unit is set to the target temperature. be able to.

An optical fiber manufacturing apparatus according to an embodiment of the present invention includes:
(7) Resin is supplied via a pipe, and the glass fiber or the coated fiber is passed through the resin coating portion that applies the resin to the outer periphery of the glass fiber or the coated fiber;
A temperature control unit for maintaining a constant temperature of the resin application part by flowing a fluid at a constant temperature around the resin application part;
A heating unit for heating at least a part of the outer periphery of the pipe;
A temperature measuring unit for measuring the resin temperature in the pipe;
A control unit that controls the heating unit such that the resin temperature in the pipe reaches a target temperature;
Have
A heating unit that heats at least a part of the outer periphery of the pipe, a temperature measurement unit that measures a resin temperature in the pipe, and a control unit that controls the heating unit so that the resin temperature in the pipe becomes a target temperature. Thereby, the fluctuation | variation of the resin temperature which flows into a resin application part can be suppressed, and it can maintain at a fixed resin temperature. And since it has the temperature control part which flows the fluid of constant temperature around the resin application part and keeps the temperature of the resin application part constant, it is possible to apply the resin whose temperature is kept constant to the glass fiber or the coated fiber. it can. Therefore, fluctuations in the coating diameter of the manufactured optical fiber and occurrence of uneven thickness can be suppressed.

[Details of the embodiment of the present invention]
Specific examples of an optical fiber manufacturing method and manufacturing apparatus according to an embodiment of the present invention will be described below with reference to the drawings.
In addition, this invention is not limited to these illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to a claim are included.

  FIG. 1 is a schematic configuration diagram of a drawing apparatus which is an example of an optical fiber manufacturing apparatus.

  In the optical fiber manufacturing apparatus 1 shown in FIG. 1, the lower end portion of the optical fiber preform 2 is heated and melted in a drawing furnace 3, and the optical fiber preform 2 is drawn. Glass fiber G1 formed by drawing optical fiber preform 2 passes through cooling device 4 provided downstream of drawing furnace 3 in the traveling direction of glass fiber G1 (the direction of arrow A in FIG. 1). . The cooled glass fiber G1 passes through a die (resin coating unit) 5 provided downstream of the cooling device 4. The dice 5 stores liquid resin 6 supplied from the resin supply unit 10. Therefore, when the glass fiber G1 passes through the die 5, the resin is applied to the outer periphery of the glass fiber G1. The manufactured optical fiber may have two or more coating layers. For example, when there are two coating layers, both the primary resin and the secondary resin, or the primary resin may be applied.

  Next, the glass fiber G <b> 1 coated with resin passes through a resin curing device 7 provided downstream of the die 5. The resin applied to the surface of the glass fiber G1 is cured to form the optical fiber G2 (for example, if the resin is an ultraviolet curable resin, an ultraviolet irradiation device or the like is used as the resin curing device). The optical fiber G2 formed by passing through the resin curing device 7 is wound around the winding drum 8c through the guide roller 8a and the take-up portion 8b.

  As shown in the graph of FIG. 2, for example, the viscosity of the resin 6 applied to the optical fiber G2 decreases as the resin temperature increases. As described above, since the viscosity decreases as the resin temperature increases, the coating diameter of the optical fiber becomes thinner as the resin temperature increases, as shown in the graph of FIG. 3, for example. In addition, uneven thickness may occur in the coating due to fluctuations in the resin temperature. For this reason, it is necessary to keep the temperature of the resin 6 in the die 5 at a constant target temperature such that the coating diameter is within the standard range.

  As described above, in order to keep the temperature of the resin 6 in the die 5 at a constant target temperature, it is necessary to suppress the temperature fluctuation of the resin supplied from the resin supply unit 10 to the die 5. Therefore, the optical fiber manufacturing apparatus according to the present embodiment is capable of suppressing temperature fluctuations of the resin flowing through the pipe 12 when manufacturing the optical fiber. FIG. 4 is a diagram illustrating the resin supply unit 10 for suppressing temperature fluctuation of the resin.

  The resin supply unit 10 shown in FIG. 4 supplies the resin 6 from the resin tank 11 to the die 5 through the pipe 12. The resin supply unit 10 is provided with a heater (heating unit) 13 on the outer periphery of at least a part of the pipe 12. In addition, the resin supply unit 10 includes a temperature measurement unit (for example, a thermocouple) 14 that measures the resin temperature in the pipe 12. And the resin supply part 10 is provided with the control part 15 which controls the heater 13 so that the resin temperature in the piping 12 may become target temperature. In addition, a temperature adjusting unit 5 a that keeps the temperature of the die 5 constant by flowing a fluid 5 b at a constant temperature is provided around the die 5.

  By the way, in order to control the resin temperature in the die 5 and the temperature of the resin 6 entering the die 5 to be the same, the resin temperature in the die 5 is directly measured, and the control unit is based on the measurement result. It is considered ideal that 15 controls the heater 13. However, when a temperature measuring device such as a thermocouple is inserted in the die 5, the flow of the resin in the die 5 is disturbed to affect the state of application of the resin 6 to the glass fiber G1, and the quality of the optical fiber G2 to be manufactured. May be damaged. For this reason, it is difficult to measure the resin temperature in the die 5.

  From the above, the resin supply unit 10 measures the temperature of the resin 6 entering the die 5, and the control unit 15 controls the heater 13 so that the resin temperature in the pipe 12 becomes the target temperature. Further, a temperature control part 5a is provided around the die 5 so that the temperature of the resin 6 stored in the die 5 does not change. In the resin supply unit 10, it is preferable to measure the resin temperature in the pipe 12 between the pipe 12 and the die 5 where the heater 13 is provided. . The pipe part 12a connected to the die 5 is provided with a joint 16 so that it can be removed from the pipe 12 when the die 5 is replaced, for example, and a temperature measuring part 14 is provided inside the joint 16 to adjust the resin temperature. It is good to measure. The pipe 12 is made of, for example, metal or resin, and is preferably made of a material having good heat insulation.

In addition, the resin supply unit 10 includes a resin tank 11 that stores the resin 6 supplied to the pipe 12. FIG. 5 is a configuration diagram of the resin tank 11.
As shown in FIG. 5, the resin tank 11 includes, for example, a main tank 11a and a sub tank 11b. When the resin 6 in the main tank 11a decreases, the resin 6 is supplied from the sub tank 11b through the conduit 11c. When the resin 6 in the sub tank 11b decreases, the resin 6 may be poured into the sub tank 11b as indicated by an arrow B. For example, a fluid 11e such as water having a constant temperature heated by the fluid heating unit 11d is allowed to flow around the outer periphery of the resin tank 11 (the main tank 11a and the sub tank 11b) to heat the resin tank 11 so that the temperature becomes constant. Good.

Next, the manufacturing method of the optical fiber in this embodiment is demonstrated.
In the optical fiber manufacturing method according to the present embodiment, resin is supplied to a die (resin application unit) 5 via a pipe 12, and the glass fiber G1 is passed through the die 5 to apply the resin 6 to the outer periphery of the glass fiber G1. It has a resin coating process. This resin coating process will be described in detail below.

(Resin application process)
First, a constant temperature fluid 5 b is flowed around the dice (resin application part) 5 to keep the temperature of the dice 5 constant. On the other hand, the control unit 15 controls the heater (heating unit) 13 provided on at least a part of the outer periphery of the pipe 12 so that the resin temperature in the pipe 12 becomes the target temperature. Then, the resin 6 is supplied to the die 5 through the pipe 12, and the glass fiber G1 is passed through the die 5 to apply the resin 6 to the outer periphery of the glass fiber G1.

  The resin temperature is preferably measured by the temperature measuring unit 14 in the pipe 12 and the heater 13 is controlled so that the measured temperature becomes the target temperature. Since the resin temperature is measured in the pipe 12, the resin temperature in the pipe 12 can be grasped more accurately.

  For example, the resin temperature may be measured in the pipe 12 between the pipe 12 and the die 5 where the heater 13 is provided. When there is a difference between the resin temperature supplied into the pipe 12 and the pipe temperature of the portion where the heater 13 is provided, the pipe temperature and the resin temperature heated by the heater 13 gradually while the resin 6 moves. And approaching. For this reason, the resin temperature of the part nearer to the die 5 is controlled to the target temperature by measuring the resin temperature, for example, in the joint 16 of the pipe 12 between the part of the pipe 12 and the die 5 provided with the heater 13. be able to.

  The resin tank 11 may be heated so that the temperature of the resin tank 11 containing the resin 6 supplied to the pipe 12 is constant. Since the resin tank 11 is heated so that the temperature of the resin tank 11 becomes constant, the temperature of the resin supplied into the pipe 12 is stabilized, so that the temperature fluctuation of the resin 6 supplied to the die 5 is more reliably suppressed. it can.

  Further, the temperature set value of the heater 13 may be set higher than the temperature of the die 5. Since the temperature setting value of the heater 13 is set higher than the temperature of the die 5, even if the resin temperature decreases after passing through the portion where the heater 13 is provided, the temperature can be kept close to the temperature of the die 5.

  The heater 13 may be controlled in consideration of a decrease in the resin temperature until the resin 6 in the pipe 12 in the portion where the heater 13 is provided is supplied into the die 5. Since the heater 13 is controlled in consideration of a decrease in the resin temperature until the resin 6 in the pipe 12 in the portion where the heater 13 is provided is supplied into the die 5, the resin temperature entering the die 5 is set to the target temperature. can do.

  As described above in detail, according to the manufacturing method and the manufacturing apparatus 1 of the optical fiber G2 according to this embodiment, the heater 13 provided on the outer periphery of at least a part of the pipe 12 so that the resin temperature becomes the target temperature. To control. Thereby, even if a temperature variation occurs in the resin 6 flowing through the pipe 12 when the optical fiber G2 is manufactured, the temperature variation of the resin 6 flowing to the die 5 can be suppressed and kept at a constant resin temperature. And since the fluid 5b of constant temperature is poured around the die | dye 5 and the temperature of the die | dye 5 is made constant, the resin 6 with which temperature was kept constant can be apply | coated to the glass fiber G1. Therefore, the fluctuation | variation of the coating diameter of the optical fiber G1 manufactured and generation | occurrence | production of thickness deviation can be suppressed.

  In the above embodiment, the coating layer of the optical fiber G1 to be manufactured may be two or more layers. For example, when the coating layer has a two-layer structure of a primary layer and a secondary layer, and the optical fiber manufacturing apparatus includes two dies 5, the resin shown in FIG. 4 is placed on each die 5 or one of the dies 5. A supply unit 10 may be provided.

  Further, the optical fiber manufacturing apparatus of the present invention is not limited to an apparatus for forming a coating on a drawn glass fiber G1 as in the above embodiment, but for coloring a coated fiber on which a coating layer has already been formed. The present invention can also be applied to the coloring process in which the above resin is applied.

DESCRIPTION OF SYMBOLS 1 Optical fiber manufacturing apparatus 2 Optical fiber preform 3 Drawing furnace 4 Cooling device 5 Dice (resin coating part)
5a Temperature control unit 6 Resin 7 Resin curing device 8a Guide roller 8b Take-up unit 8c Winding drum 10 Resin supply unit 11 Resin tank 11a Main tank 11b Sub tank 11c Pipe line 11d Fluid heating unit 11e Fluid 12 Piping 13 Heater (heating unit)
14 Temperature Measurement Unit 15 Control Unit 16 Joint G1 Glass Fiber G2 Optical Fiber

Claims (7)

Manufacturing of an optical fiber including a resin coating step of supplying a resin to a resin coating section through a pipe and passing the glass fiber or the coated fiber through the resin coating section and coating the resin on the outer periphery of the glass fiber or the coated fiber A method,
In the resin application step,
A constant temperature fluid is allowed to flow around the resin application part to keep the temperature of the resin application part constant,
An optical fiber manufacturing method of controlling a heating unit provided on an outer periphery of at least a part of the pipe so that a resin temperature in the pipe becomes a target temperature.   The method for manufacturing an optical fiber according to claim 1, wherein the resin temperature is measured in the pipe, and the heating unit is controlled so that the measured temperature becomes the target temperature.   The method for manufacturing an optical fiber according to claim 1 or 2, wherein the resin temperature is measured in the pipe between the pipe in a portion where the heating unit is provided and the resin coating unit.   The method for manufacturing an optical fiber according to any one of claims 1 to 3, wherein the resin tank is heated so that a temperature of a resin tank that stores the resin supplied to the pipe is constant.   The manufacturing method of the optical fiber as described in any one of Claims 1-4 which sets the temperature setting value of the said heating part higher than the temperature of the said resin application part.   The optical fiber manufacturing according to claim 5, wherein the heating unit is controlled in consideration of a decrease in resin temperature until the resin in the pipe of the part provided with the heating unit is supplied into the resin coating unit. Method. Resin is supplied through a pipe, and a glass fiber or a coated fiber is passed therethrough to apply the resin to the outer periphery of the glass fiber or the coated fiber; and
A temperature control unit for maintaining a constant temperature of the resin application part by flowing a fluid at a constant temperature around the resin application part;
A heating unit for heating at least a part of the outer periphery of the pipe;
A temperature measuring unit for measuring the resin temperature in the pipe;
A control unit that controls the heating unit such that the resin temperature in the pipe reaches a target temperature;
An optical fiber manufacturing apparatus.

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