JPH09197209A - Coated optical fiber ribbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the increase in the light loss of coated optical fiber ribbons in winding on bobbins and cabling by specifying the coeffts. of dynamic friction of the coated optical fiber ribbons with each other, thereby providing the coated optical fiber ribbons with good self-lubricity. SOLUTION: The coeffts. of dynamic friction of the coated optical fiber ribbons 1 with each other are specified to <=0.7. The integral coating layers 3 of the coated optical fiber ribbons 1 are so formed as to consist of resin compsns. contg. lubricative resins. The integral coating layers 3 are formed by arranging optical fibers 2 in parallel with each other and coating the circumferences thereof with resins. The coeffts. of dynamic friction of the integral coating layers 3 with each other which are <=0.7 signify that the coeffts. of dynamic friction of the coated optical fiber ribbons 1 are 0.7. The coeffts. of dynamic friction of the integral coating layers 3 are obtd. by changing the compsns. of the resins constituting the integral coating layers 3 or adhering lubricants to the surfaces of the integral coating layers 3 or changing the conditions for producing the integral coating layers 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber ribbon which is capable of slipping on the surface of the optical fiber ribbon to prevent an increase in optical loss during bobbin winding or cable formation.

[0002]

2. Description of the Related Art FIG. 2 is a sectional view showing an example of an optical fiber ribbon. The optical fiber tape core wire 1 is formed by arranging a plurality of optical fiber element wires 2 in parallel, and forming a collective coating layer 3 made of a resin on the circumference thereof to be integrated into a tape shape. The optical fiber ribbon 1 can handle a plurality of optical fiber strands 2 collectively, and can also collectively connect the plurality of optical fiber strands 2 at the time of connection, so that the connection time is short. Good work efficiency. Further, since it is more compact than the case where each optical fiber element wire 2 is made into a separate core wire, it has advantages such as being preferable for achieving high-density mounting of optical fibers when constructing an optical cable. .

The optical fiber ribbon 1 is manufactured by forming a collective coating layer 3 of resin on the circumference of a plurality of optical fiber strands 2. The obtained optical fiber ribbon 1 is obtained.
Is usually stored in a state of being wound on a bobbin having a diameter of about 300 mm. However, depending on the conditions at the time of manufacturing the optical fiber ribbon 1 and the material properties of the collective coating layer 3, the surface of the collective coating layer 3 may be difficult to slip. In this case, when the optical fiber tape core wire 1 is wound around the bobbin, the winding state is disturbed and the optical fiber tape core wire 1 is inverted or bent, so that the optical loss of the optical fiber tape core wire 1 occurs. The problem arises that

When forming an optical cable, a plurality of optical fiber ribbons 1 may be piled up. However, if the surface of the collective coating layer 3 of the optical fiber ribbons 1 is difficult to slip, the cable is bent. At this time, stress tends to concentrate when the optical fiber ribbon core wire 1 meanders in the cable, so that the optical loss of the optical fiber ribbon core wire 1 may increase due to bending or lateral pressure.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to prevent an increase in the optical loss of the optical fiber ribbon when the bobbin is wound or formed into a cable.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that the coefficient of dynamic friction between the optical fiber ribbons is 0.7 or less. Is. The invention according to claim 2 is the optical fiber ribbon according to claim 1, wherein the collective coating layer of the optical fiber ribbon is made of a resin composition containing a lubricating resin.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to FIGS. 1 and 2. The optical fiber strand 2 used in the present invention is not particularly limited, but a bare optical fiber having an outer diameter of 125 μm is coated with an ultraviolet curable resin (UV resin) to have an outer diameter of 250 μm is generally used.
The number of optical fiber strands forming the optical fiber ribbon 1 may be any number of 2 or more.

The collective coating layer 3 is preferably formed by arranging the optical fiber strands 2 in parallel so that their peripheral surfaces are in contact with each other, and coating the periphery of these with a resin. The collective coating layer 3 is formed such that the optical fiber ribbon 1 has a flat cross section. If the thickness of the collective coating layer 3 is too thin, the mechanical strength of the optical fiber tape core wire 1 becomes low, and if it is too thick, it is disadvantageous for high density storage in the cable. Therefore, the thickness of the collective coating layer 3 can be appropriately set depending on the application of the optical fiber ribbon 1 and the type of resin forming the collective coating layer 3. For example, the optical fiber element wire 2 having an outer diameter of 250 μm is 4 When the optical fiber tape core wire 1 is constructed by using the present invention, the tape width is 1 mm to
It is preferably formed to have a thickness of 1.3 mm and a tape thickness of about 0.3 mm to 0.5 mm.

In the present invention, the collective coating layer 3 is formed on the collective coating layer 3 of the same material so that the dynamic friction coefficient obtained by the measuring method described later is 0.7 or less. In the present invention, the coefficient of dynamic friction between the collective coating layers 3 is 0.7.
The following means that the coefficient of dynamic friction between the optical fiber ribbons 1 is 0.7 or less. The dynamic friction coefficient of the collective coating layer 3 is obtained by, for example, changing the composition of the resin forming the collective coating layer 3, by attaching a lubricant to the surface of the collective coating layer 3, and / or
Alternatively, it can be performed by changing the manufacturing conditions of the collective coating layer 3.

As a resin that can be preferably used for reducing the dynamic friction coefficient of the surface of the collective coating layer 3, for example, a resin composition in which a lubricating resin is dispersed in a resin such as polyethylene or polypropylene can be mentioned. Examples of the lubricating resin include a polyorganosiloxane, a block copolymer of a polyorganosiloxane and a polyolefin such as polyethylene, a fluororesin, or a copolymer of a fluororesin and another resin. Then, the dynamic friction coefficient of the collective coating layer 3 can be controlled by changing the type and content of the lubricating resin. Examples of the lubricant that can be attached to the surface of the collective coating layer 3 to reduce the dynamic friction coefficient include talc, silicone oil, paraffin oil, polyethylene wax and the like. Further, in order to reduce the dynamic friction coefficient of the surface of the collective coating layer 3 by controlling the manufacturing conditions, for example, purging or the like for making it difficult for oxygen inhibition during surface hardening may be performed.

The method of measuring the dynamic friction coefficient of the optical fiber ribbon 1 according to the present invention will be described below. FIG.
FIG. 3 is a schematic configuration diagram showing an example of an apparatus used for measuring a dynamic friction coefficient in the present invention. In the figure, reference numeral 1 is an optical fiber tape core wire whose dynamic friction coefficient is to be measured, 11
Is a mandrel, 12 is a load cell, and 13 is a weight. The mandrel 11 has a cylindrical shape and an outer diameter of 10
It is formed at 0 mm. On the circumference of the mandrel 11,
An optical fiber tape core wire 1 whose dynamic friction coefficient is to be measured is attached along the circumferential direction. The optical fiber ribbons 1 on the peripheral surface of the mandrel 11 are arranged so that the side surfaces of the adjacent optical fiber ribbons 1 contact each other. The mandrel 11 is fixed such that the diameter direction thereof is the vertical direction, and the same optical fiber tape core wire 1 as the optical fiber tape core wire 1 attached to the peripheral surface is hung along the peripheral direction. Both ends of the optical fiber ribbon 1 which is hung on the mandrel 12 are in a hanging state, and a 100 g weight 1 is attached to one end.
3 is attached. A load cell 12 is attached to the mandrel 11, and the load cell 12
The load F is measured when the other end of the optical fiber ribbon 1 which is hung on the mandrel 12 is pulled vertically downward (indicated by an arrow in the figure).

When measuring the coefficient of dynamic friction, the optical fiber ribbon 1 is pulled downward in the vertical direction and the mandrel 1 is pulled.
The optical fiber tape core wire 1 hung on 1 is 100 m
The load F (g) when moving at a speed of / minute is measured. The dynamic friction coefficient μ between the optical fiber ribbons 1 is calculated by the following mathematical expression (I). μ = (1 / 2π) ln (F / 100) (I)

Hereinafter, the reason why the dynamic friction coefficient μ between the optical fiber ribbons 1 in the present invention is set to 0.7 or less will be described. Table 1 below shows the results of measuring the optical loss when optical fiber ribbons 1 having different dynamic friction coefficients μ were produced and wound around bobbins.
That is, first, four single-mode optical fiber strands 2 having an outer diameter of 250 μm are arranged in parallel, and a collective coating layer 3 is extrusion-coated on the circumferences thereof to form a four-core optical fiber tape core as shown in FIG. Line 1 was made. The tape width of the optical fiber ribbon 1 was 1.2 mm, and the tape thickness was 0.35 mm. The collective coating layer 3 was formed by using an ultraviolet-curable urethane acrylate, and by changing the resin composition, 6 types of optical fiber ribbons 1 having different surface slip characteristics were produced (No. 1 to 6). .

The coefficient of dynamic friction μ of the obtained optical fiber ribbon 1 was measured using the apparatus shown in FIG. The results are shown in Table 1 below. Moreover, the obtained optical fiber tape core wire 1
Was wound around a bobbin having an outer diameter of 300 mm. The length of the wound optical fiber tape core wire 1 is 10 km, and the winding tension is 1.
It was 50 g. With the bobbin wound like this,
The optical loss of the optical fiber ribbon 1 is measured by OTDR (optical
time domain reflectometer). The measurement wavelength was 1.55 μm. The optical loss was measured for each of the four optical fiber strands 2 constituting the optical fiber tape core wire 1, and the largest value is shown in Table 1 below.

[0015]

[Table 1]

From the results shown in Table 1, the coefficient of dynamic friction μ is 0.83.
With the above optical fiber ribbons (Nos. 4 and 5), the maximum value of optical loss suddenly increased. When the optical fiber ribbon 1 wound on the bobbin was observed, no.
The winding state of the optical fiber ribbons 1 and 4 of the optical fiber tape 4 was disordered. It is considered that this is because the bobbin winding progressed while the optical fiber ribbons 1 were bent or inverted because the overlapping optical fiber ribbons 1 could not move smoothly when wound around the bobbin. To be The increase in light loss increases as the dynamic friction coefficient μ increases. The optical fiber ribbon with a dynamic friction coefficient μ of 1.05 (No. 6) exceeded the dynamic range (20 dB / km) of OTDR, so that the optical loss could not be measured. Conversely, the coefficient of dynamic friction μ is 0.43, 0.52
And 0.69 optical fiber ribbon (No. 1,
In Nos. 2 and 3), the maximum value of the optical loss was small and almost constant, and the disorder of the winding state of the optical fiber ribbon 1 was not observed. From these results, when the dynamic friction coefficient μ between the optical fiber ribbons 1 is 0.7 or less, the self-lubricating property of the optical fiber ribbons 1 prevents the winding state from being disturbed when wound around the bobbin. It is recognized that you can do it. Further, if the optical fiber ribbons 1 have self-lubricating properties in this way, the optical fiber ribbons 1 in the cable can be formed even when a plurality of optical fiber ribbons 1 are stacked to form a cable. It is possible to suppress the bending of the light and suppress an increase in light loss.

[0017]

As described above, the optical fiber ribbon of the present invention is characterized in that the coefficient of dynamic friction between the optical fiber ribbons is 0.7 or less. Since the optical fiber ribbon according to the present invention has a good self-lubricating property, it is possible to prevent the optical loss of the optical fiber ribbon from increasing during bobbin winding or cable formation. Specifically, when the collective coating layer of the optical fiber ribbon is formed using a resin composition containing a lubricating resin, an optical fiber ribbon having good self-lubricating property can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of an apparatus used for measuring a dynamic friction coefficient in the present invention.

FIG. 2 is a cross-sectional view showing an example of an optical fiber ribbon.

[Explanation of symbols]

1 ... Optical fiber tape core wire, 2 ... Optical fiber element wire, 3 ...
Collective coating layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Araki 1440 Rokuzaki, Sakura City, Chiba Prefecture Fujikura Ltd. Sakura Factory

Claims (2)

[Claims] 1. An optical fiber ribbon, wherein the coefficient of dynamic friction between the optical fiber ribbons is 0.7 or less. 2. The optical fiber tape core wire according to claim 1, wherein the collective coating layer of the optical fiber tape core wire is made of a resin composition containing a lubricating resin.