JP2019178031A - Resin feeding device, resin feeding method and optical fiber drawing device - Google Patents

Abstract

An object of the present invention is to provide a resin supply device, a resin supply method, and an optical fiber drawing device that can reduce bubbles generated when resin is supplied to a tank. A tank for storing a resin to be supplied to an optical fiber resin coating device, a resin supply pipe for connecting the tank to the optical fiber resin coating device and supplying the resin from the tank to the optical fiber resin coating device, and a tank And a resin supply pipe for supplying the resin to the tank, the resin supply port of the resin supply pipe is located below an arbitrary predetermined liquid level lower limit position in the tank. [Selection diagram] Fig. 1

Description

  The present invention relates to a resin supply device, a resin supply method, and an optical fiber drawing device.

  In an optical fiber manufacturing process, a resin coating apparatus for coating an ultraviolet curable resin on an optical fiber drawn from an optical fiber preform is used. As the resin coating apparatus, a resin supply apparatus that supplies resin to a resin coater (die) is used (for example, Patent Document 1).

JP-A-6-227846

  FIG. 3 is a schematic diagram of a resin supply apparatus according to a conventional example. A resin supply device 100A shown in FIG. 3 includes a first tank 101 that stores a resin 110 that is an ultraviolet curable resin to be supplied to an optical fiber resin coater (die) 130, and a replenishment to the first tank 101. A second tank 105 for storing the resin 110 is provided. The second tank 105 is a large tank for storing resin 110 purchased from a chemical company or the like directly. The first tank 101 is an intermediate tank for adjusting the pressure, temperature, etc. of the resin 110 supplied from the second tank 105 and supplying it to the die 130. The first tank 101 and the die 130 are formed by a resin supply pipe 102 in which an opening end portion 102a on one end side is positioned near the bottom in the first tank 101 and an opening end portion 102b on the other end side is connected to the die 130. It is connected. The resin 110 in the first tank 101 is pressurized by the pressurized gas supplied from the pressurized gas supply pipe 104 connected to the upper part of the first tank 101, so that the resin supply pipe 102 It is fed to the dice 130 through. The first tank 101 and the second tank 105 have an opening end 103a on one end side located near the bottom in the second tank 105, and an opening end (resin replenishing port) 103b on the other end side being the first. It is connected by the resin replenishment pipe | tube 103 for replenishing the resin 110 in the 2nd tank 105 in the 1st tank 101 located between the liquid level upper limit in the tank 101, and a liquid level lower limit. The resin 110 in the second tank 105 is supplied to the first tank 101 through the resin supply pipe 103 by being pumped up by a pump 120 provided in the middle of the resin supply pipe 103.

  However, in the resin supply apparatus 100A as shown in FIG. 3, the opening end 103b of the resin supply pipe 103 may be positioned above the liquid level 111 in the first tank 101. In this case, when the resin 110 in the second tank 105 is supplied into the first tank 101 through the resin supply pipe 103, the resin 110 is discharged from the opening end 103b of the resin supply pipe 103 located above the liquid level 111. Therefore, many bubbles 140 are generated in the resin 110 in the first tank 101 due to the entrainment of the pressurized gas. For this reason, the bubbles 140 may be sent together with the resin 110 from the first tank 101 to the die 130, and a problem that a coating defect occurs is likely to occur.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a resin supply device, a resin supply method, and an optical fiber drawing device that can reduce bubbles generated when resin is supplied to a tank. That is.

  In order to solve the above-described problems and achieve the object, a resin supply apparatus according to the present invention connects a tank for storing resin to be supplied to an optical fiber resin coater, and the tank and the optical fiber resin coater. A resin supply device comprising: a resin supply pipe for supplying resin from the tank to the optical fiber resin coater; and a resin supply pipe for supplying resin to the tank. Resin of the resin supply pipe The replenishing port is located below an arbitrary liquid level lower limit position set in advance in the tank.

  The resin supply method according to the present invention includes a resin supply step of supplying resin through a resin supply pipe from a tank storing resin to an optical fiber resin coater, a resin supply step of supplying resin through the resin supply pipe to the tank, A liquid level control step for controlling the liquid level in the tank so that the liquid level of the resin in the tank is positioned above the resin supply port of the resin supply pipe. It is what.

  An optical fiber drawing apparatus according to the present invention includes the resin supply apparatus according to the above-described invention.

  In the resin supply device, the resin supply method, and the optical fiber drawing device according to the present invention, since the resin supply port of the resin supply tube is always located below the liquid level in the tank, gas entrainment occurs when the resin is supplied. It is restrained and the effect that the bubble generated at the time of resin replenishment to a tank can be reduced is produced.

FIG. 1 is a schematic diagram of a resin supply apparatus according to an embodiment. FIG. 2 is a schematic diagram of a drawing apparatus for manufacturing an optical fiber using the resin supply apparatus according to the embodiment. FIG. 3 is a schematic diagram of a resin supply apparatus according to a conventional example.

  Below, one Embodiment of the resin supply apparatus and resin supply method which concern on this invention is described. Note that the present invention is not limited to this embodiment.

  FIG. 1 is a schematic diagram of a resin supply apparatus 100 according to the embodiment. The resin supply device 100 according to the embodiment includes a first tank 1 that stores a resin 10 that is an ultraviolet curable resin to be supplied to a die 30 that is an optical fiber resin coater, and a replenishment to the first tank 1. A second tank 5 for storing the resin 10 is provided. The second tank 5 is a large tank for directly storing and storing a resin 10 purchased from, for example, a chemical company. The first tank 1 is an intermediate tank for adjusting the pressure, temperature, etc. of the resin 10 supplied from the second tank 5 and supplying it to the die 30. The first tank 1 and the die 30 are connected by a resin supply pipe 2 for supplying the resin 10 from the first tank 1 to the die 30. The resin supply pipe 2 has an open end 2a on one end, which is the first tank 1 side, positioned near the bottom in the first tank 1, and an open end 2b on the other end, which is on the die 30 side. 30. Further, one end of a pressurized gas supply pipe 4 for supplying an inert gas such as nitrogen gas or a pressurized gas such as air is connected to the upper portion of the first tank 1. The resin 10 in the first tank 1 is pressurized by the pressurized gas supplied from the pressurized gas supply pipe 4 into the first tank 1 at a predetermined pressure at which the liquid level 11 becomes a desired resin supply amount. As a result, the resin is supplied to the die 30 through the resin supply pipe 2.

  The first tank 1 and the second tank 5 are connected by a resin supply pipe 3 for supplying the resin 10 in the second tank 5 to the first tank 1. The resin replenishment pipe 3 has an open end 3a on one end, which is the second tank 5 side, located near the bottom in the second tank 5, and an open end (resin replenishment) on the other end, which is the first tank 1 side. (Mouth) 3b is positioned below an arbitrary liquid level lower limit position set in the first tank 1 in advance. The resin 10 in the second tank 5 is supplied to the first tank 1 through the resin supply pipe 3 by being pumped up by a pump 20 provided in the middle of the resin supply pipe 3.

  The first tank 1 is provided with a resin amount detector (not shown) that detects the amount of resin in the first tank 1. As this resin amount detector, for example, a capacitance sensor, a weight scale, or the like can be used.

  In the resin supply apparatus 100 according to the embodiment, by supplying the resin 10 from the first tank 1 to the die 30 through the resin supply pipe 2, the resin 10 in the first tank 1 is reduced, and the resin in the first tank 1 is reduced. When the resin amount is detected by the resin amount detector that the resin level has reached the lower limit value at which the height of the liquid level 11 becomes the liquid level lower limit position, the pump 20 operates and passes through the resin supply pipe 3 from the second tank 5. Supply of the resin 10 to the first tank 1 is started. Thereafter, when the resin amount detector detects that the amount of resin in the first tank 1 has reached the upper limit value at which the height of the liquid level 11 reaches the upper limit position of the liquid level, the pump 20 stops and the second tank 5 The supply of the resin 10 to the first tank 1 is finished.

  As described above, in the resin supply apparatus 100 according to the embodiment, the first tank 1 is appropriately changed so that the height of the liquid level 11 is maintained between the liquid level upper limit position and the liquid level lower limit position. The resin 10 is supplied from the second tank 5 to the first tank 1. That is, the resin supply device 100 according to the embodiment is configured so that the liquid level 11 of the resin 10 in the first tank 1 is positioned above the opening end 3b of the resin supply pipe 3. The surface height is controlled.

  Thereby, in the resin supply apparatus 100 according to the embodiment, the opening end 3 b of the resin supply pipe 3 is always located below the liquid surface 11 of the resin 10 in the first tank 1. Therefore, when the resin 10 is supplied from the second tank 5 through the resin supply pipe 3 to the first tank 1, the resin 10 in the first tank 1 is pressurized even if the resin 10 is discharged from the opening end 3 b. Gas entrainment is suppressed, and bubbles in the resin 10 generated when the resin is supplied to the first tank 1 can be reduced. Therefore, it is possible to suppress coating defects that may be caused by air bubbles being sent from the first tank 1 to the die 30 together with the resin 10.

  FIG. 2 is a schematic diagram of an optical fiber drawing device 40 that manufactures an optical fiber using the resin supply device 100 according to the embodiment. The optical fiber preform 50 is made of, for example, quartz glass and is manufactured by a known method such as a VAD method, an OVD method, or an MCVD method. The end portion of the optical fiber preform 50 is heated and melted by a heater 41 which is a heating device disposed around the optical fiber preform 50, drawn, and the glass optical fiber 51 is drawn.

  Below the heater 41, a die 30 for applying an ultraviolet curable resin to the outer periphery of the glass optical fiber 51 is provided. The die 30 is connected to the resin supply pipe 2 of the resin supply device 100. As described with reference to FIG. 1, the resin supply device 100 is a resin that is an ultraviolet curable resin in the first tank 1 by the pressurized gas supplied into the first tank 1 from the pressurized gas supply pipe 4. The resin 10 is supplied from the first tank 1 to the dice 30 through the resin supply pipe 2 by pressurizing the ten liquid surfaces 11 at a predetermined pressure so as to obtain a desired resin supply amount. The die 30 is, for example, a die that collectively applies a primary coating material and a secondary coating material of an optical fiber. A plurality of dies may be provided separately for the primary coating material die and the secondary coating material die. In this case, a resin supply device is connected to each die. The glass optical fiber 51 drawn from the optical fiber preform 50 is coated with the primary coating material and the secondary coating material by applying the ultraviolet curable resin supplied from the resin supply device 100 in the die 30. 52.

  Below the die 30, an ultraviolet irradiation device 42 that irradiates the optical fiber 52 coated with the primary coating material and the secondary coating material with ultraviolet rays is provided. The ultraviolet irradiation device 42 includes an arbitrary ultraviolet light source such as a semiconductor light emitting element or a mercury lamp. The optical fiber 52 coated with the ultraviolet curable resin by the resin coating device 24 enters the ultraviolet irradiation device 42 and is irradiated with ultraviolet rays. As a result, the two layers of ultraviolet curable resin coated on the outer periphery of the optical fiber 52 are cured, and the two layers of ultraviolet curable resin become a primary layer and a secondary layer.

  The optical fiber 52 having the primary layer and the secondary layer formed on the outer periphery, that is, the optical fiber strand, is guided by the guide roller 43 and wound by the winding device 44. In this way, the optical fiber is manufactured.

  The present invention is not limited to the above embodiment. What was comprised combining each component mentioned above suitably is also contained in this invention. Further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made.

1,101 First tank 2,102 Resin supply pipe 3,103 Resin supply pipe 4,104 Pressurized gas supply pipe 5,105 Second tank 10,110 Resin 11,111 Liquid level 20,120 Pump 30,130 Optical fiber Resin coater (die)
40 Optical fiber drawing device 41 Heater 42 Ultraviolet irradiation device 43 Guide roller 44 Winding device 50 Optical fiber preform 51 Glass optical fiber 52 Optical fiber 100, 100A Resin supply device 140 Air bubbles

Claims (3)

A tank for storing resin to be supplied to the optical fiber resin coater;
A resin supply pipe for connecting the tank and the optical fiber resin coater, and supplying resin from the tank to the optical fiber resin coater;
A resin supply pipe for supplying resin to the tank;
In a resin supply device comprising:
A resin supply apparatus, wherein a resin supply port of the resin supply pipe is located below an arbitrary liquid level lower limit position set in advance in the tank. A resin supply step of supplying the resin through a resin supply pipe from the tank storing the resin to the optical fiber resin coater;
A resin replenishment step of replenishing resin through a resin replenishment pipe to the tank;
A liquid level control step for controlling the liquid level in the tank so that the liquid level of the resin in the tank is located above the resin supply port of the resin supply pipe;
The resin supply method characterized by having.   An optical fiber drawing device comprising the resin supply device according to claim 1.

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