JPH08152546A - Apparatus for production of coated optical fiber ribbon and production method therefor - Google Patents

Abstract

PURPOSE: To produce a coated optical fiber ribbon at a low cost and high yield by decreasing the amt. of the cooling gas to be used and surely curing a UV curing type resin. CONSTITUTION: The coated optical fiber ribbon 1 is formed by delivering optical fibers 2 from delivery bobbins 11, lining up the optical fibers 2 with a coating device 13 and coating these fibers with an uncured UV curing type resin. A UV curing device 14 is provided with a UV permeable tube 22 and a piping 18 is installed at the device. A cooling gas is passed from a cooling gas supplying section 15. The coated optical fiber ribbon 1 is passed into the UV permeable tube 22 and the UV curing type resin is cured by irradiating the resin with UV rays from a UV lamp 21. The concn. of oxygen in the atmosphere gas in the UV permeable tube 22 is monitored by an oxygen sensor 19 and its monitor signal is sent to an oxygen concn. controller 17. The oxygen concn. controller 17 generates a control signal for controlling the oxygen concn. to a prescribed value or below to operate the valve of a gas flow regulator 16, thereby regulating the flow rate of the gas until the oxygen concn. in the cooling gas attains the prescribed value or below.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for manufacturing an optical fiber ribbon.

[0002]

2. Description of the Related Art Conventionally, an optical fiber ribbon has been formed by arranging optical fiber strands and applying an uncured ultraviolet curable resin to form a tape, which is irradiated with ultraviolet rays while flowing a cooling gas to cure the ultraviolet curable resin. It was manufactured. This manufacturing method is disclosed in, for example, JP-A-1-191110.

FIG. 2 is a side view of an example of a conventional optical fiber ribbon.

The optical fiber tape core wire 1 is formed by arranging a plurality of optical fiber element wires 2 to be core wires and arranging them, and covering them with an ultraviolet curable resin 3 to form a tape. In this example, the number of optical fiber strands is four, but the number of optical fiber strands can be changed as necessary.

FIG. 3 is a block diagram of an example of a conventional optical fiber tape core wire manufacturing apparatus.

Optical fiber forming the optical fiber ribbon
The bar wire 2 is wound around a sending bobbin 11. Light
Sending bobbin 1 when the fiber tape has 4 cores
Four 1s are prepared. The optical fiber strand 2 is fed by each
It is delivered from the delivery bobbin 11 to the coating device 13. Coating
In the device 13, four optical fiber strands 2 are arranged and uncured
As shown in Fig. 2, the UV curable resin of
Iva tape core 1 Optical fiber ribbon 1 is purple
It is sent to the outside line curing device 34. UV curing device 34
Has a UV lamp (not shown) inside as a UV source
The ultraviolet curable resin which has the resin is irradiated with ultraviolet rays to be cured.
With this ultraviolet irradiation, the temperature inside the ultraviolet curing device 34 becomes ultraviolet.
If the temperature rises above the gasification temperature of the curable resin, the optical fiber
Since the core wire 1 is damaged, the cooling gas flows from the pipe 18.
And cool it down to about 600 ° C,
Preventing damage. Hardened fiber optic tape
The winding core wire 1 is wound around a winding bobbin 12. cold
He, Ar, N is used as the return gas ₂Inert gas such as
It

FIG. 4 is a sectional view of another example of the ultraviolet curing device of the conventional optical fiber ribbon manufacturing apparatus.

The ultraviolet curing device 34 can have a structure as shown in FIG. That is, the double pipe 32
Further, an ultraviolet lamp 21 as an ultraviolet source is provided outside this, and the ultraviolet lamp 21 and the double tube 32 are surrounded by an elliptical reflecting mirror 23. The double tube 32 is made of a material that transmits ultraviolet rays and is formed as a double tube having a vacuum layer. This double tube 3
The optical fiber tape core wire 1 coated with resin 2 is passed through and ultraviolet rays are irradiated to cure the ultraviolet curable resin. Double tube 3
Reference numeral 2 serves to thermally shield the optical fiber ribbon 1 from the ultraviolet lamp 21 and keep the surface temperature of the optical fiber ribbon 1 at a low temperature. The elliptical reflecting mirror 23 is made by utilizing the property that all the light from one focal point of the ellipse is focused on the other focal point, and the ultraviolet lamp 21 is placed at one focal point of the elliptic reflecting mirror 23 and the other focal point When the optical fiber tape core wire 1 is placed on the optical fiber tape core wire 1, all the light from the ultraviolet lamp 21 is collected on the optical fiber tape core wire 1, so that the resin can be efficiently cured. Further, ultraviolet rays and heat rays are emitted from the ultraviolet lamp 21, but the heat rays are absorbed by the heat ray absorber of the elliptical reflecting mirror 23 and the double tube 32 and do not reach the optical fiber tape core wire 1. Keep line 1 cold.

[0009]

However, in the optical fiber ribbon manufacturing apparatus shown in FIG. 3, about 60 liters / liter is used to cool the surface of the optical fiber ribbon.
It is necessary to flow more than a minute of gas, which causes turbulence in the gas, which not only impairs the smoothness of the surface of the optical fiber ribbon, but also increases the cooling gas cost and increases the cost. There's a problem. When expensive rare gas such as He or Ar is used as the cooling gas, a cooling gas circulation device is attached to the ultraviolet curing device to save gas consumption, but the inlet and outlet of the optical fiber ribbon cannot be sealed. , The cooling gas leaks from there. If the flow rate of the cooling gas is large, the leakage amount of the cooling gas increases in proportion to the flow rate of the cooling gas. Therefore, there is a problem that the amount of the cooling gas consumed increases and the cost increases.
In addition, if a gas of about 60 liters / minute or more is constantly supplied, the temperature inside the ultraviolet curing device 34 (usually about 900 ° C.) will be about 60.
The temperature is lowered to 0 ° C. or lower to lower the degree of curing of the resin. This decrease in the degree of curing damages the surface of the optical fiber ribbon when the guide is touched during winding of the optical fiber ribbon, or sticks the optical fiber ribbons to each other when wound around the winding bobbin 12. Cause micro-bending. On the other hand, if the output of the ultraviolet lamp is increased to increase the degree of curing of the resin, the ultraviolet lamp is overloaded and the life of the ultraviolet lamp is shortened.

In the case of the ultraviolet curing device shown in FIG. 4, the heat is cut off by the double tube 32, and the heat ray from the ultraviolet lamp is absorbed by the heat ray absorber of the elliptical reflecting mirror 23 and the double tube 32 so that the optical fiber tape core. Although the wire 1 is kept at a low temperature, the temperature of the optical fiber tape core wire rises above the gasification temperature of the ultraviolet curable resin due to the energy of the ultraviolet rays incident on the optical fiber tape core wire and the reaction heat of resin curing. However, there is a problem that the optical fiber ribbon is damaged. Further, if the cooling gas is not supplied, the gas generated during the curing reaction stagnates without flowing and the curing reaction is hindered by a component of the gas.

An object of the present invention is to provide an optical fiber tape core wire manufacturing apparatus capable of reducing the amount of cooling gas used, reliably curing an ultraviolet curable resin, and manufacturing at a low cost and a high yield. Especially.

An object of the present invention is to provide a method for manufacturing an optical fiber ribbon which can reduce the amount of cooling gas used, reliably cure an ultraviolet curable resin, and can be manufactured at a low cost and a high yield. Especially.

[0013]

According to a first aspect of the present invention, there is provided an apparatus for manufacturing an optical fiber ribbon core wire, wherein a delivery bobbin for sending out an optical fiber wire serving as a core wire and an uncured ultraviolet ray in which the optical fiber wire is lined up. A coating device for coating a curable resin to form an optical fiber tape core wire, an ultraviolet curing device for irradiating the optical fiber tape core wire with ultraviolet rays to cure the ultraviolet curable resin, and a cooling gas for the ultraviolet curing device. In a manufacturing apparatus of an optical fiber tape core wire having a cooling gas supply unit for supplying, and a winding bobbin for winding an optical fiber tape core wire in which an ultraviolet curable resin is cured, the light provided in the ultraviolet curing apparatus is used. An ultraviolet transparent tube for passing a fiber tape core wire, a pipe attached so as to supply a cooling gas only into the ultraviolet transparent tube, and the ultraviolet transparent tube An oxygen sensor for monitoring the oxygen concentration in the atmosphere gas, an oxygen concentration controller for generating a control signal for controlling the oxygen concentration in the atmosphere gas to a predetermined value or less by a monitoring signal from the oxygen sensor, and the oxygen concentration And a gas flow rate adjuster for adjusting the flow rate of the cooling gas according to a control signal from the controller.

According to a second aspect of the present invention, there is provided an optical fiber ribbon core wire manufacturing method, in which optical fiber strands are arranged and an uncured ultraviolet curable resin is applied to form a tape. In the method for producing an optical fiber tape core wire by irradiating the ultraviolet curable resin, the optical fiber tape core wire is passed through an ultraviolet transparent tube provided in the ultraviolet curing device, and the inside of the ultraviolet transparent tube is The cooling gas is flowed only to monitor the oxygen concentration in the atmosphere gas, and ultraviolet rays are irradiated to cure the ultraviolet curable resin while adjusting the cooling gas flow rate so that the oxygen concentration becomes a predetermined value or less. And

A third aspect of the invention is characterized in that the predetermined value of the oxygen concentration in the atmosphere gas is 3%.

[0016]

In the manufacturing apparatus of the present invention, an ultraviolet ray transmitting tube is provided in the ultraviolet ray curing apparatus, and the optical fiber tape core wire is passed through the ultraviolet ray transmitting tube to allow the cooling gas to flow. The amount can be reduced, the amount of cooling gas used can be reduced, and the cost can be reduced. Further, the oxygen sensor monitors the oxygen concentration in the atmospheric gas, and the oxygen concentration controller and the gas flow rate controller are configured to control the concentration of oxygen that prohibits resin curing to a predetermined value or less,
A high-quality optical fiber tape core wire in which the resin is sufficiently cured can be manufactured with a high yield.

In the present invention, ultraviolet rays are radiated while flowing a cooling gas to monitor the concentration of oxygen that inhibits the curing of the resin that occurs during the curing reaction, and the oxygen concentration is controlled to a predetermined value or less. A high-quality optical fiber tape core wire in which the resin is sufficiently cured can be manufactured with a high yield.

If the oxygen concentration in the atmospheric gas is suppressed to 3% or less, it is possible to manufacture a good-quality optical fiber tape core wire in which the resin is sufficiently cured.

[0019]

1 is a block diagram and a sectional view of a manufacturing apparatus and an ultraviolet curing apparatus therefor according to an embodiment of the present invention.

In the manufacturing apparatus of this embodiment, a plurality of feeding bobbins 11 for feeding the optical fiber strands 2 and a plurality of optical fiber strands 2 are arranged side by side and coated with an uncured ultraviolet curable resin to form an optical fiber tape. Covering device 13 for core 1
An ultraviolet curing device 14 for irradiating the optical fiber tape core wire 1 with ultraviolet rays to cure the ultraviolet curable resin,
Inside the ultraviolet curing device 14, a cooling gas supply unit 15 and a pipe 18 for supplying a cooling gas to the ultraviolet curing device 14, a winding bobbin 12 for winding the optical fiber tape core wire 1 in which the ultraviolet curing resin is cured, An ultraviolet light transmitting tube 22 provided through which the optical fiber ribbon 1 is passed, an ultraviolet lamp 21 as an ultraviolet light source through which the optical fiber ribbon 1 is irradiated with ultraviolet rays to cure an ultraviolet curable resin, and an ultraviolet ray transmitting tube 22. An oxygen sensor 19 for monitoring the oxygen concentration in the atmosphere gas inside, and an oxygen concentration controller 17 for generating a control signal for controlling the oxygen concentration in the atmosphere gas to a predetermined value or less by a monitoring signal from the oxygen sensor 19. And a gas flow rate controller 16 for adjusting the flow rate of the cooling gas according to a control signal from the oxygen concentration controller 17. FIG.
As shown in (b), it is more preferable to provide the ellipsoidal reflecting mirror 23 in the ultraviolet curing device 14 and dispose the ultraviolet lamp 21 and the ultraviolet transparent tube 22 at the two focal points thereof.

The UV transparent tube 22 is made of a UV transparent material such as quartz glass, and the pipe 18 is directly connected to the UV transparent tube 22 so that the cooling gas can flow only in the UV transparent tube 22. The UV transparent tube 22 need not be a double tube having a vacuum layer, but a single wall tube is sufficient. The probe of the oxygen sensor 19 is arranged in the ultraviolet ray transmitting tube 22. The oxygen sensor 19 measures the oxygen concentration in the atmospheric gas, outputs the measured value as a monitoring signal, and transmits it to the oxygen concentration controller 17. When the oxygen concentration controller 17 receives the monitoring signal, the oxygen concentration controller 17 controls the oxygen concentration in the atmospheric gas to be a predetermined value or less according to the oxygen concentration, that is, if the oxygen concentration is higher than the predetermined value, the cooling gas flow rate is increased. Then, a control signal for lowering the oxygen concentration is generated, and if the oxygen concentration falls below a predetermined value, a control signal for returning the cooling gas flow rate to the original flow rate is generated. The gas flow controller 16 adjusts the opening of the valve according to the control signal to adjust the gas flow rate from the cooling gas supply unit 15, that is, if the control signal indicates that the oxygen concentration is higher than a predetermined value, If the control signal indicates that the opening is increased to increase the cooling gas flow rate and the oxygen concentration is equal to or lower than the predetermined value, the valve opening is decreased to return the cooling gas flow rate to the original flow rate. Since the cooling gas is a gas for cooling the optical fiber ribbon and keeping it at a constant temperature, the cooling gas has a constant flow rate unless the oxygen concentration exceeds a predetermined value. Here, as the gas flow rate regulator 16, for example, a mass flow controller is used.

Next, a method of manufacturing the optical fiber ribbon according to the present invention will be described with reference to FIGS.

The temperature inside the UV transparent tube 22 is set to about 600.degree.
In advance, a gas flow rate value that can be maintained is set, the gas flow rate of the gas flow rate controller 16 is set to that value, and the cooling gas is supplied from the cooling gas supply unit 15 to the ultraviolet ray transmitting tube 22 of the ultraviolet curing device 14. Although the flow rate set value varies depending on the device, in the case of the present embodiment, the flow rate can be set to 20 liters / minute because the cooling gas is flowed only to the ultraviolet permeable tube 22. This flow rate is about ⅓ of the conventional flow rate, and the gas cost is reduced to about ⅓, turbulence is eliminated, and the smoothness of the surface of the optical fiber ribbon is maintained. The ultraviolet lamp 21, the oxygen sensor 19, the oxygen concentration controller 17, and the gas flow rate controller 16 are turned on and brought into operation. The optical fiber strand 2 which is the core of the optical fiber tape 1 is sent out from the bobbin 11 to the coating device 13, and the coating device 1
The uncured UV curable resin 3 is coated with 3 to form the optical fiber tape core wire 1 and sent to the UV curing device 14. The ultraviolet curing device 14 irradiates ultraviolet rays to cure the ultraviolet curable resin 3. Optical fiber tape core wire 1 obtained by curing resin 3
Take up on the bobbin 12.

In the curing reaction of the ultraviolet curable resin 3,
If oxygen is present in the reaction system, curing is blocked, so it is necessary to control so that oxygen does not exist near the resin.
Oxygen is contained in the uncured resin raw material and may leak into the ultraviolet curing device 14 from the outside. Therefore,
The oxygen concentration in the atmospheric gas is constantly monitored, and when the oxygen concentration exceeds a predetermined value, the flow rate of the cooling gas is increased so that the oxygen concentration becomes equal to or lower than the predetermined value. The oxygen concentration is preferably 0, but it is difficult to set it to 0. Therefore, the oxygen concentration is set to 3% or less, which is the limit that does not prevent curing.

[0025]

As described above, according to the present invention, the ultraviolet ray transmitting device is provided with the ultraviolet ray transmitting tube, and the cooling gas is allowed to flow only in the ultraviolet ray transmitting tube to control the oxygen concentration in the atmospheric gas to a predetermined value or less. Since a device that can be used is installed, the amount of cooling gas used can be reduced, turbulent flow of cooling gas can be eliminated, and the UV curable resin can be reliably cured. It is possible to obtain an optical fiber ribbon manufacturing apparatus which can manufacture the fiber ribbon at a low cost and a high yield.

Further, according to the present invention, the cooling gas is allowed to flow only in the ultraviolet ray transmitting tube provided in the ultraviolet ray curing device to control the oxygen concentration in the atmospheric gas to a predetermined value or less to cure the ultraviolet ray curing resin. As a result, the amount of cooling gas used can be reduced, turbulent flow of cooling gas can be eliminated, and the UV curable resin can be reliably cured. Wires can be manufactured at low cost and high yield.

[Brief description of drawings]

FIG. 1 is a block diagram and a sectional view of a manufacturing apparatus and an ultraviolet curing apparatus therefor according to an embodiment of the present invention.

FIG. 2 is a side view of an example of a conventional optical fiber ribbon.

FIG. 3 is a block diagram of a conventional apparatus for manufacturing an optical fiber ribbon.

FIG. 4 is a cross-sectional view of another example of the ultraviolet curing device of the conventional optical fiber ribbon manufacturing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber tape core wire 2 Optical fiber element wire 3 Ultraviolet curing resin 11 Outgoing bobbin 12 Winding bobbin 13 Coating device 14 Ultraviolet curing device 15 Cooling gas supply part 16 Gas flow rate regulator 17 Oxygen concentration controller 18 Piping 19 Oxygen sensor 21 UV lamp 22 UV transparent tube 23 Elliptical mirror

Claims (3)

[Claims] 1. A feed-out bobbin for feeding an optical fiber as a core wire, a coating device for arranging the optical fiber wires to coat an uncured ultraviolet curable resin to form an optical fiber tape core wire, and the light An ultraviolet curing device that irradiates the fiber tape core with ultraviolet rays to cure the ultraviolet curing resin, a cooling gas supply unit that supplies a cooling gas to the ultraviolet curing device, and an optical fiber tape core in which the ultraviolet curing resin is cured. In an optical fiber tape core wire manufacturing apparatus having a winding bobbin for winding a wire, an ultraviolet ray transmissive tube that is provided in the ultraviolet ray curing device and passes through the optical fiber tape core wire, and cools only in the ultraviolet ray transmissive tube. A pipe attached so as to supply gas, an oxygen sensor for monitoring the oxygen concentration in the atmospheric gas in the ultraviolet-transparent pipe, and the oxygen sensor An oxygen concentration controller for generating a control signal for controlling the oxygen concentration in the atmosphere gas to a predetermined value or less by a monitoring signal from the above, and a gas flow rate adjustment for adjusting the flow rate of the cooling gas by the control signal from the oxygen concentration controller. An optical fiber tape core wire manufacturing apparatus comprising: 2. An optical fiber for arranging optical fiber strands and applying an uncured ultraviolet curable resin to form a tape, and irradiating ultraviolet rays while flowing a cooling gas through an ultraviolet curing device to cure the ultraviolet curable resin. In the method for manufacturing a tape core wire, the optical fiber tape core wire is passed through an ultraviolet transparent tube provided in the ultraviolet curing device, and the cooling gas is allowed to flow only in the ultraviolet transparent tube, and the oxygen concentration in the atmospheric gas is increased. Is monitored and ultraviolet rays are irradiated while the cooling gas flow rate is adjusted so that the oxygen concentration becomes a predetermined value or less, and the ultraviolet curable resin is cured. 3. The method for manufacturing an optical fiber ribbon according to claim 2, wherein the predetermined value of the oxygen concentration in the atmosphere gas is 3%.