Method for manufacturing optical fiber tape core and device for manufacturing optical fiber tape core

Abstract

The present invention relates to a device (100) for manufacturing an optical fiber tape core (10) in which a plurality of single-core coated optical fibers (20) arranged in parallel are partially connected, the device being characterized by comprising: a coating part (110) for applying an uncured resin to the plurality of single-core coated optical fibers (20) arranged in parallel; a removal part (120) for partially removing the applied uncured resin in an atmosphere capable of suppressing generation of air bubbles in the uncured resin between adjacent ones of the single-core coated optical fibers (20); and a curing part (130) for curing the uncured resin remaining in the plurality of single-core coated optical fibers without being removed.

Description

Optical fiber ribbon manufacturing apparatus and optical fiber ribbon manufacturing method

[0001] The present invention relates to an optical fiber ribbon manufacturing apparatus and an optical fiber ribbon manufacturing method.

[0002] In recent years, data traffic has increased dramatically due to the spread of the Internet of Things (IoT), the full-scale commercialization of 5G, and autonomous driving of automobiles, and demand is growing for the development and construction of high-speed, large-capacity optical fiber communication networks to support this. In order to economically realize the development and construction of high-speed, large-capacity optical fiber communication networks, it is important to accommodate as many mono-coated optical fibers (optical fibers) as possible in existing ducts. When accommodating many mono-coated optical fibers in an existing duct, a rollable ribbon (optical fiber ribbon) in which mono-coated optical fibers are intermittently connected is used from the viewpoint of workability in wiring installation work (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a method for manufacturing such an optical fiber ribbon. In this manufacturing method, a UV-curable resin is applied to a plurality of parallel-arranged single-coated optical fibers, the applied uncured UV-curable resin is partially removed, and the resin remaining on the plurality of optical fibers is cured with UV light to obtain an optical fiber ribbon. Here, the removal unit for partially removing the applied uncured resin has a rotary blade with a recess (notch). The rotation of the rotary blade with the notch allows the UV-curable resin to be partially removed.

[0004] JP 2010-33010 A

[0005] However, when removing the uncured resin as disclosed in Patent Document 1, air may get trapped in the uncured resin, causing bubbles to form. If the uncured resin is cured in a state where bubbles have formed, voids may form in the cured resin, which may reduce the strength of the optical fiber ribbon.

[0006] The object of the present invention is to provide an optical fiber ribbon manufacturing apparatus and an optical fiber ribbon manufacturing method that can suppress the generation of air bubbles in uncured resin when removing the applied uncured resin.

[0007] According to one aspect of the present invention for solving the above problem, there is provided an optical fiber ribbon manufacturing apparatus in which a plurality of single-coated optical fibers arranged in parallel are partially connected, the optical fiber ribbon manufacturing apparatus comprising: a coating unit for applying uncured resin to the plurality of single-coated optical fibers arranged in parallel; a removal unit for partially removing the applied uncured resin in an atmosphere that can suppress the generation of bubbles in the uncured resin between adjacent single-coated optical fibers; and a curing unit for curing the uncured resin that has not been removed and remains on the plurality of single-coated optical fibers.

[0008] According to another aspect of the present invention, there is provided a method for manufacturing an optical fiber ribbon in which a plurality of single-coated optical fibers arranged in parallel are partially connected, the method comprising the steps of: applying uncured resin to the plurality of single-coated optical fibers arranged in parallel; partially removing the applied uncured resin in an atmosphere that can suppress the generation of bubbles in the uncured resin between adjacent single-coated optical fibers; and curing the uncured resin that remains on the plurality of single-coated optical fibers without being removed.

[0009] According to the present invention, it is possible to provide an optical fiber ribbon manufacturing apparatus and an optical fiber ribbon manufacturing method that can suppress the generation of air bubbles in uncured resin when removing the applied uncured resin.

[0010] 1A to 1C are schematic diagrams showing an optical fiber ribbon. Fig. 2A is a diagram showing the schematic configuration of an optical fiber ribbon manufacturing apparatus, and Fig. 2B is a cross-sectional view of a removal unit. Fig. 3 is a flowchart of a method for manufacturing an optical fiber ribbon.

[0011] An optical fiber ribbon manufacturing apparatus and an optical fiber ribbon manufacturing method according to a preferred embodiment of the present invention will be described below. In this specification, the lower and upper limits of numerical ranges indicated by "to" are included in the numerical range. First, the optical fiber ribbon to be manufactured will be described, and then the optical fiber ribbon manufacturing apparatus and the optical fiber ribbon manufacturing method will be described.

[0012] [Configuration of Optical Fiber Ribbon] Fig. 1A is a schematic plan view of the optical fiber ribbon 10, Fig. 1B is a cross-sectional view taken along line B-B in Fig. 1A, and Fig. 1C is a cross-sectional view taken along line C-C in Fig. 1A. In Fig. 1, the connecting portion 30 is shown in black in order to distinguish between the connecting portion 30 and the separating portion 40 for easy viewing.

[0013] As shown in Fig. 1A, in an optical fiber ribbon 10, a plurality of single-coated optical fibers 20 are arranged in parallel. Connection portions 30 and spacing portions 40 are intermittently present between the plurality of parallel-arranged single-coated optical fibers 20. The connection portions 30 are portions where the UV-curable resin has hardened, and the spacing portions 40 are portions where no hardened resin is present. The optical fiber ribbon 10 having the connection portions 30 and spacing portions 40 intermittently as shown in Fig. 1A is easy to fold in the width direction and can be formed into a bundle, which is useful for increasing the density of the single-coated optical fibers 20.

[0014] 1B is a cross-sectional view taken along line BB in FIG. 1A, ie, at the connecting portion 30, and FIG. 1C is a cross-sectional view taken along line CC in FIG. 1A, ie, at the separating portion 40. As shown in FIG.

[0015] 1B and 1C, the mono-coated optical fiber 20 has, from its center outward, an optical fiber strand 21, a primary coating layer 22, and a secondary coating layer 23. As shown in Figures 1B and 1C, a cured resin 50 is present around the two mono-coated optical fibers 20. The cured resin 50 functions as a tape layer 60 on the surface of the optical fiber ribbon 10, and functions as a connecting portion 30 between the two mono-coated optical fibers 20.

[0016] As can be seen from FIG. 1C , in the cross section of the separation portion 40, the cured resin 50 is present around each of the two single-coated optical fibers 20, but the cured resin 50 is not present between the two single-coated optical fibers 20, which forms the separation portion 40.

[0017] [Optical fiber ribbon core wire manufacturing apparatus, optical fiber ribbon core wire manufacturing method] Figure 2A is a schematic oblique view of an optical fiber ribbon core wire manufacturing apparatus 100, Figure 2B is a vertical cross-sectional view of a portion of Figure 2A, and Figure 3 is a flowchart of an optical fiber ribbon core wire manufacturing method.

[0018] 2A, the optical fiber ribbon manufacturing apparatus 100 has a coating unit 110 for applying uncured resin, a removal unit 120 for partially removing the applied uncured resin, and a curing unit 130 for curing the remaining uncured resin. In the optical fiber ribbon manufacturing apparatus 100, the coating unit 110, the removal unit 120, and the curing unit 130 are arranged in this order along the running direction of the multiple single-coated optical fibers 20.

[0019] 3, a step (S110) of applying uncured resin to the mono-coated optical fiber 20 is performed by the coating unit 110, a step (S120) of partially removing the uncured resin is performed by the removal unit 120, and a step (S130) of curing the uncured resin is performed by the curing unit 130. In this embodiment, the uncured resin is UV-curable resin before it is cured. Each of these steps will be described below.

[0020] The coating section 110 receives the plurality of mono-coated optical fibers 20 that have been running and arranged in parallel, and applies uncured resin to coat the periphery of the optical fibers. The coating section 110 has an incoming section 111 for receiving the plurality of mono-coated optical fibers 20, and an outgoing section 112 for discharging the plurality of mono-coated optical fibers 20 to which the uncured resin has been applied. The plurality of mono-coated optical fibers 20 that have been output from the outgoing section 112 are entirely covered with uncured resin and formed into a tape shape.

[0021] The removal unit 120 partially removes the uncured resin applied to the plurality of single-coated optical fibers 20 between adjacent single-coated optical fibers 20 so as to obtain an optical fiber ribbon 10 having intermittent connection portions 30 (see Figure 1A).

[0022] 2B is a cross-sectional view along the length of the optical fiber ribbon 10, showing details of the removing section 120. As shown in FIG. 2B , the removing section 120 includes a cutting die 121, a rotary blade 122 disposed in the cutting die 121, a gas filling section 123, and a gas supply section 124 for supplying gas to the gas filling section 123.

[0023] As shown in Fig. 2A, the cutting die 121 has a plurality of rotary blades 122 arranged in the width direction of the optical fiber ribbon 10, and a plurality of slits 126 arranged in the width direction of the optical fiber ribbon 10, each corresponding to one of the rotary blades 122. As shown in Fig. 2B, the rotary blade 122 has a blade portion 122a and a notch portion 122b. The blade portion 122a can protrude from the slit 126 when the rotary blade 122 rotates, but the notch portion 122b cannot protrude from the slit 126 when the rotary blade 122 rotates. As a result, when the rotary blade 122 rotates, the blade portion 122a intermittently protrudes from the slit 126, and the uncured resin between the plurality of single-coated optical fibers 20 running on the slit 126 is partially (intermittently) removed. On the other hand, when the notch 122b is positioned relative to the slit 126 and the blade portion 122a does not protrude, the uncured resin is not removed and remains partially (intermittently) on the plurality of mono-coated optical fibers 20. In this embodiment, the rotary blade 122 rotates so as to follow the running direction of the plurality of mono-coated optical fibers 20.

[0024] 2B , in the rotary blade 122, the blade portion 122a and the notch portion 122b are disposed at the same radial distance from the center of rotation of the rotary blade 122. The circumferential lengths of the blade portion 122a and the notch portion 122b are factors that determine the lengths of the connecting portion 30 and the separating portion. Note that the method for removing the uncured resin is not limited to the method using the rotary blade 122 as described above. The uncured resin may also be removed mechanically, for example, by a member that moves up and down.

[0025] If the uncured resin is removed in air as described above, air may get into the uncured resin, generating bubbles as described above, which may reduce the strength of the optical fiber ribbon 10. According to the optical fiber ribbon manufacturing apparatus 100 and manufacturing method of the present embodiment, the uncured resin is removed in an atmosphere that suppresses the generation of bubbles, thereby suppressing the generation of bubbles.

[0026] 2B, the dividing die 121 is disposed in a gas filling section 123, and a gas A (hereinafter simply referred to as gas A) capable of suppressing the generation of bubbles is supplied to the gas filling section 123 from a gas supply section 124. This reduces the concentration of air, and suppresses the generation of bubbles even when the uncured resin is mechanically removed by the rotary blade 122.

[0027] The gas filling section 123 is preferably configured to be able to fill the gas A around the plurality of mono-coated optical fibers 20 traveling within the cutting die 121. Furthermore, it is even more preferable that the gas filling section 123 be configured to be able to fill the gas A around the blade portions 122a of the rotary blade 122. For example, if the density of the gas A is higher than the density of air, the gas filling section 123 may be a box with an open top, as shown in FIG. 2B . In this case, it is preferable that the gas filling section 123 be configured to be able to fill the gas A up to a position higher than the uncured resin of the plurality of mono-coated optical fibers 20 traveling within the cutting die 121. Furthermore, it is even more preferable that the gas filling section 123 be configured to be able to fill the gas A up to a position higher than the maximum height position that the blade portions 122a of the rotary blade 122 can reach.

[0028] Air bubbles may be generated not only when the uncured resin is removed, but also when a plurality of mono-coated optical fibers 20 enter the entry portion 121a of the cutting die 121. Therefore, from the viewpoint of suppressing the generation of air bubbles, the gas filling portion 123 is preferably configured to be able to fill the area around the entry portion 121a of the cutting die 121 with gas. When the density of the gas A is higher than the density of air, the gas filling portion 123 is preferably configured to be able to fill the gas up to a position higher than the height of the entry portion 121a of the cutting die 121.

[0029] The gas A for creating the bubble generation-suppressing atmosphere is not particularly limited as long as it can suppress the generation of bubbles. If the atmosphere is air, the generation of bubbles cannot be suppressed as described above. Here, air is a gas whose main components are oxygen and nitrogen. Therefore, gases containing large amounts of oxygen and nitrogen are thought to be more likely to generate bubbles. For this reason, it is thought that the gas for creating the bubble generation-suppressing atmosphere is preferably a gas containing a lower concentration of oxygen or nitrogen than air.

[0030] The reason why air is prone to generating bubbles is presumed to be as follows. That is, it is presumed that oxygen and nitrogen in air have low solubility in uncured resin or low diffusibility, which makes them prone to generating bubbles. Therefore, it is considered preferable that gas A used to create a bubble-generation-suppressing atmosphere has a higher solubility in uncured resin than oxygen or nitrogen, or a higher diffusibility in uncured resin than oxygen or nitrogen. As a result, it is presumed that even if gas A penetrates into the uncured resin, it dissolves in the uncured resin and does not generate bubbles, or even if it penetrates, it diffuses and is expelled to the outside of the uncured resin, thereby not generating bubbles.

[0031] Furthermore, it is preferable that the density of gas A is higher than the density of air. That is, it is preferable that gas A is heavier than air. This makes it possible to prevent gas A from remaining in gas filling section 123 and diffusing into the air even if the top of gas filling section 123 is open, making it easier to maintain an atmosphere that suppresses bubble generation. Examples of such gas A include carbon dioxide.

[0032] In this embodiment, the bubble generation suppression atmosphere is a carbon dioxide atmosphere. Carbon dioxide is preferable because it is heavier than air and is thought to have high solubility in uncured resin. The concentration of carbon dioxide in the carbon dioxide atmosphere may be any concentration that can suppress the generation of bubbles. The carbon dioxide concentration in the carbon dioxide atmosphere is, for example, a concentration in which carbon dioxide is the main component, e.g., 90% or more.

[0033] Furthermore, the gas A used to create the bubble generation suppression atmosphere is preferably one that is highly safe for humans and non-flammable.

[0034] The method for creating the bubble generation suppression atmosphere is not limited to the above-described method using the gas filling section 123. For example, to create the bubble generation suppression atmosphere, gas A may be blown onto the portion where the uncured resin is to be removed and onto the entry portion 121 a of the dividing die 121.

[0035] The configuration of the gas supply unit 124 is not particularly limited as long as it can supply the gas A into the gas filling unit 123. In this embodiment, the gas supply unit 124 is disposed below the gas filling unit 123.

[0036] The curing unit 130 cures the uncured resin that was not removed by the removal unit 120. There are no particular limitations on the curing unit 130 as long as it can perform this function. In this embodiment, the curing unit 130 has a first light irradiation unit 131 arranged upstream and a second light irradiation unit 132 arranged downstream. The first light irradiation unit 131 irradiates the uncured resin with light to semi-cure the uncured resin. The second light irradiation unit 132 further irradiates light to completely cure the semi-cured resin. In this embodiment, the cumulative irradiation amount of each is adjusted so that the cumulative irradiation amount of the first light irradiation unit 131 is smaller and the cumulative irradiation amount of the second light irradiation unit 132 is larger. The irradiated light is ultraviolet (UV) light.

[0037] (Effects) According to this embodiment, the number of air bubbles in the uncured resin is reduced, thereby reducing voids in the cured resin. This improves the adhesive strength of the joints of the optical fiber ribbon. Furthermore, according to this embodiment, the occurrence of blisters (water entering the cured resin) can be prevented during reliability testing (hot water testing) of the optical fiber ribbon, thereby reducing optical loss during testing and improving the long-term reliability of the optical fiber (reducing breakage of the optical fiber ribbon).

[0038] The optical fiber ribbon manufacturing apparatus according to the present invention is useful for manufacturing optical fiber ribbons used in, for example, high-speed, large-capacity optical fiber communication networks.

[0039] REFERENCE SIGNS LIST 10 Optical fiber ribbon 20 Single-coated optical fiber 21 Optical fiber 22 Primary coating layer 23 Secondary coating layer 30 Connection section 40 Separation section 50 Cured resin 60 Tape layer 100 Optical fiber ribbon manufacturing apparatus 110 Coating section 111, 121a Input section 112 Output section 120 Removal section 121 Cutting die 122 Rotary blade 122a Blade section 122b Notch section 123 Gas filling section 124 Gas supply section 126 Slit 130 Curing section 131 First light irradiation section 132 Second light irradiation section

Claims

1. An optical fiber ribbon manufacturing apparatus in which a plurality of single-coated optical fibers arranged in parallel are partially connected, comprising: a coating unit for applying uncured resin to the plurality of single-coated optical fibers arranged in parallel; a removal unit for partially removing the applied uncured resin between adjacent single-coated optical fibers in an atmosphere that can prevent air bubbles from forming in the uncured resin; and a curing unit for curing the uncured resin that remains on the plurality of single-coated optical fibers without being removed.

2. An optical fiber ribbon manufacturing apparatus according to claim 1, characterized in that the atmosphere has a lower oxygen or nitrogen concentration than the oxygen or nitrogen concentration of air.

3. An optical fiber ribbon manufacturing apparatus according to claim 1, characterized in that the atmosphere is a carbon dioxide atmosphere.

4. An optical fiber ribbon manufacturing apparatus according to claim 1, characterized in that the removal unit has a rotary blade for removing the unhardened resin.

5. A method for manufacturing an optical fiber ribbon in which a plurality of single-coated optical fibers arranged in parallel are partially connected, comprising the steps of: applying uncured resin to the plurality of single-coated optical fibers arranged in parallel; partially removing the applied uncured resin in an atmosphere that can suppress the generation of bubbles in the uncured resin between adjacent single-coated optical fibers; and curing the uncured resin that remains on the plurality of single-coated optical fibers without being removed.

6. A method for manufacturing an optical fiber ribbon according to claim 5, characterized in that the atmosphere has a lower oxygen or nitrogen concentration than the oxygen or nitrogen concentration of air.

7. A method for manufacturing an optical fiber ribbon according to claim 5, characterized in that the atmosphere is a carbon dioxide atmosphere.

8. A method for manufacturing an optical fiber ribbon according to claim 5, characterized in that the removing step removes the unhardened resin with a rotating blade.

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