JPH11231182A - Fiber ribbon type optical cable and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a fiber ribbon type optical cable which has small loss variation against cable bending. SOLUTION: This fiber ribbon type optical cable 10 is constituted by stacking and housing coated optical fiber ribbons 5 consisting of optical fibers arranged in parallel in gap parts 2 of a cable core 4; and a lubricant 7 is introduced into between the coated optical fiber ribbons 5 and a waterproof admixture 6 is introduced into between the internal walls of the gap parts of the cable core 4 and the coated optical fibers ribbons 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape type optical cable in which an optical fiber ribbon and a waterproof mixture are inserted into a gap of a cable core, and a method of manufacturing the same.

[0002]

2. Description of the Related Art An optical fiber ribbon optical cable having a structure in which an optical fiber ribbon is stacked and housed in a cable core having a groove-like or pipe-like void portion has a high density, and connection is made in units of a tape. It has excellent features such as ease of operation and is generally used.

[0003] When a tape-type optical fiber cable of this kind is bent, the optical fiber located at the outer peripheral portion of the bend undergoes elongation strain, and the optical fiber located at the bent inner portion undergoes compressive strain. Since the elongational strain promotes the elongation of a crack on the surface of the optical fiber, it is not preferable to continuously apply a large amount of strain over a long period in terms of long-term reliability. In addition, since the optical fiber ribbon cable having the spiral groove has a structure in which the optical fiber ribbon is wound around the cable core, a lateral pressure is applied to the optical fiber when the strain occurs. Therefore, the elongation must be suppressed from the viewpoint of the increase in transmission loss due to the lateral pressure.

[0004] For this purpose, there has been described a method of making the optical fiber ribbon easy to move by the effect of the fine particle size powder, reducing the friction, and suppressing the maximum strain applied when the optical fiber ribbon is bent. (Japanese Patent Laid-Open No. 62-9 / 1987)
No. 8314). In addition, when a waterproofing mixture is stored in the groove in addition to the optical fiber ribbon, the waterproofing mixture swells in the covering material of the tape and the consistency at a low temperature is reduced. (U
SP 5,013,126).

[0005]

Problems to be Solved by the Invention
As described in Japanese Patent Publication No. 4 (1999) -1994, a tape type optical fiber cable in which particles are interposed between optical fiber ribbons is used to transport and lay the cable repeatedly while bending. As a result, the sliding effect fluctuated, and it was difficult to maintain transmission characteristics stably.

As described in US Pat. No. 5,013,126, in a tape type optical cable in which an optical fiber tape core and a waterproof mixture are accommodated in a groove, if an oil having a molecular weight of 300 or less is used, the oil becomes a tape core. Swell to the line, 30
If it exceeds 0, the transmission loss increases due to the decrease in the consistency. In addition, when the admixture is oxidized, the low-molecular components of the oil are decomposed, and the transmission loss is increased due to a decrease in the consistency. In addition, the low-molecular components penetrate into the core fiber of the tape and peel off the coating.

Further, since the optical fiber ribbons are stacked and housed, a portion where the optical fiber ribbons come into close contact with each other is generated, and the strain is concentrated on the portion, thereby increasing the loss. was there.

Accordingly, an object of the present invention is to solve such a problem and to reduce the elongation strain applied to the optical fiber ribbon.
An object of the present invention is to provide a tape-type optical fiber cable having less loss fluctuation with respect to cable bending.

[0009]

According to the present invention, there is provided a tape optical fiber cable in which a plurality of optical fiber ribbons arranged in parallel are stacked and housed in a gap of a cable core. In the optical fiber cable,
A lubricant is introduced between the optical fiber ribbons, and a waterproof mixture is introduced between the inner wall of the gap and the optical fiber ribbon.

According to the optical fiber ribbon cable of the present invention, by interposing a lubricant such as talc between the optical fiber tapes, it is possible to suppress the surface of the adjacent optical fiber tapes from adhering, or It is possible to obtain a cable having a stable transmission characteristic without reducing friction and without concentration of distortion even when the cable is bent.

Further, in the optical fiber ribbon cable of the present invention, a waterproof admixture mainly containing α-olefin-based oil or a polybutene-based oil is mainly contained between the inner wall of the gap and the optical fiber ribbon. It is preferable to interpose a mixture or the like. When the waterproof mixture is interposed between the inner wall of the gap and the optical fiber ribbon, it is possible to suppress the entry of moisture into the gap.

Conventionally, a lubricant such as talc has an effect of lowering the consistency of a waterproofing admixture, and it has been difficult to use it together. However, the peripheral portion of the optical fiber ribbon of the present invention is such that the lubricant and the waterproofing mixture are mixed, but in this region, the waterproofing mixture prevents the lubricant from volatilizing, and between the optical fiber tapes or It is held around it. On the other hand, the use of a lubricant such as talc has the effect of preventing oxidative deterioration of the waterproofing mixture, and it has been found that the consistency of the waterproofing mixture can be maintained at a predetermined value by keeping the amount within a predetermined range. The prevention of the oxidative deterioration of the waterproofing mixture depends on the low molecular components of the oil (particularly, 300
The following is effective for the decomposition.

According to the method of manufacturing a tape-type optical fiber cable according to the present invention, the cable core is stretched and guided, twisted around its axis at a constant rotation speed, and then the optical fiber ribbon is inserted into the gap of the cable core. After storing, in a method of manufacturing a tape type optical cable by providing a cable sheath on a cable core, a plurality of optical fiber tape cores are laminated and stored in a gap portion, and a waterproof admixture is press-fitted, and further, an optical fiber A lubricant is attached to the optical fiber ribbon just before the tape core is stored in the gap, and the lubricant is interposed between the optical fiber tapes.

According to the method of manufacturing the optical fiber ribbon cable according to the present invention, when the optical fiber ribbon and the waterproof mixture are introduced into the cable core void, the optical fiber tape is introduced into the void. Immediately before, the lubricant is attached to their surface by passing through the lubricant, and the lubricant can be easily interposed between the optical fiber ribbons.

[0015]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description.

(Embodiment 1) In the embodiment 1, the space portion of the cable core is a longitudinal groove provided on the outer periphery of the spacer, and the optical fiber ribbon is accommodated in this groove. Will be described. FIG.
(A) is a sectional view showing a configuration of a tape-core optical cable in which an optical fiber ribbon is stored in a groove of a spacer,
FIG. 1B is an enlarged view of the groove. The cable core 4 is formed by the strength member 1 and the spacer 3 provided on the outer periphery of the strength member 1 and having the spiral groove 2 formed in the outer circumferential longitudinal direction of the cylinder. A plurality of optical fiber ribbons 5 are stacked and accommodated in the groove 2, a lubricant 7 is introduced between the optical fiber ribbons 5, and the inner wall of the groove 2 and the optical fiber tape 5 The waterproofing mixture 6 is introduced between them, and the pressing tape 8 is wound thereon, and further,
Optical fiber cable 1 covered with cable sheath 9
0 is formed.

FIG. 2 is a sectional view showing the structure of the optical fiber ribbon. The optical fiber ribbon 5 is composed of a plurality of optical fiber wires 11 having a primary coating around the optical fiber and arranged in parallel, and the entire outer periphery thereof is covered with a coating layer 12 made of an ultraviolet curable resin or a silicone resin. Have been done.

The lubricant 7 used in the present embodiment includes:
Suitable examples include talc, water-absorbing powder or graphite powder, and specifically, Mg ₃ (Si ₄ O ₁₀ ) (O
H) Water-absorbing powders such as talc, polyacrylate-based compound, polysulfonate-based compound, polyvinyl alcohol / polyacrylonitrile-copolymerized compound and the like, which are mainly composed of ₂ , and graphite in powder form are preferred. Another suitable condition is that the lubricant is a powder material having a fine particle diameter of 50 μm or less, and further has a property of preventing the waterproof admixture from being oxidized and deteriorated. The lubricant 7 has a function of preventing adhesion of the interface at the interface with another substance and reducing friction by a roller effect.

By interposing the lubricant 7 between the optical fiber ribbons 5, the surfaces of the adjacent tape ribbons 5 do not adhere to each other and work to reduce friction, so that the cable is bent. However, the tape cores 5 can slide relative to each other.

The waterproofing mixture 6 used in the present embodiment includes a mixture containing an α-olefin-based oil as a main component,
Alternatively, an admixture containing a polybutene-based oil as a main component is mentioned as a preferable example. Specifically, an α-olefin-based oil: 86 w%, a silica: 7 w%, and a styrene-based rubber: 6
w%, antioxidant: 1 w%, an α-olefin-based oil-based blend, polybutene-based oil: 92
w%, silica: 3 w%, styrene-based rubber: 4 w%, antioxidant: 1 w%, and a mixture mainly composed of polybutene-based oil.

The consistency of the waterproofing admixture is preferably at least 200 or more at the temperature at which the cable is used. The waterproofing mixture 6 is a jelly-like mixture and has excellent lubricating and waterproof properties. When the waterproof mixture 6 is interposed between the optical fiber ribbon 5 and the wall of the groove 2,
The tape core wire 5 can move smoothly in the groove 2, and also suppresses water entering the groove 2.

At the periphery of the optical fiber ribbon 5, the lubricant 7 and the waterproof mixture 6 are mixed. In this region, the waterproof mixture 6 prevents the lubricant 7 from volatilizing, and Hold in between. On the other hand, the lubricant 7 such as talc has an effect of preventing the waterproofing mixture 6 from being oxidized and degraded, maintaining the waterproofing mixture 6 at a predetermined consistency, and preventing peeling of the tape core. When the lubricant 7 is added in a large amount to the waterproof mixture 6, the consistency of the waterproof mixture 6 tends to decrease. However, when the amount of the lubricant 7 is 5% by weight or less, the consistency does not extremely decrease. The problem of poor slippage does not occur. By the way, 1 w%, 5 w%, 10 w% of talc is added to the waterproofing mixture 6.
The consistency at −40 ° C. when added was 269, respectively.
230 and 194.

FIG. 3 is a graph showing the measured suggestive heat generated when a lubricant 7 (talc) was added to 150 mg of the waterproof mixture 6 and the temperature was maintained at 150 ° C. If the lubricant 7 is not added to the waterproofing mixture 6, a suggestive heat is generated with time, and the consistency of the waterproofing mixture 6 tends to decrease. However, when 0.1% by weight of the lubricant 7 is added, although suggestive heat is generated at first, the reaction stops soon, and the slip does not worsen without an extreme decrease in the consistency. In addition, it was confirmed that the addition of 5% by weight of the lubricant 7 hardly generates any suggestive heat, so that the consistency did not change. Therefore, 5% to 0.1% by weight of the lubricant 7
The added waterproof mixture 6 may be introduced into the groove 2 together with the optical fiber ribbon.

FIG. 4 is a schematic view showing a configuration of a manufacturing apparatus of the optical fiber ribbon cable 10. As shown in FIG. This manufacturing apparatus has a feeding drum 21 and a winding drum 28, both of which are arranged so as to rotate around a common axis with the same rotation speed and rotation direction. The feeding drum 21 has a cable core 4 having a strength member 1 at the center and a spacer 3 provided with a spiral groove 2 for accommodating a plurality of optical fiber ribbons 5 on the outer periphery of the strength member 1. It is fed out to the storage device 23 via 22. The storage device 23 is supplied with the optical fiber ribbon 5 accommodated in each groove 2 from the bobbin 26, and the jelly-shaped waterproof mixture 6 is press-fitted from the supply device 24 and injected into the groove 2. You. Immediately after the storage device 23, a tape winding device 25 is provided, whereby the holding tape 8 made of a synthetic organic material is wound on the cable core 4.
The pressing tape 8 restricts the movement of the optical fiber ribbon 5 in the radial direction.

In order to supply the optical fiber ribbon 5 with a predetermined tension into the groove 2, the optical fiber ribbon 5 is fed out from the bobbin 26 via a tension adjusting dancer roller 27. Although only one dancer roller 27 is shown in FIG. 3 for simplification, one dancer roller 27 is provided for each optical fiber ribbon 5. In order to prevent the optical fiber tape cores 5 from adhering to each other, the tape cores 5 are passed through a container 29 containing the lubricant 7 immediately before being supplied to the groove 2 so that the lubricant 7 is adhered to the surface. In FIG. 4, only one container 29 is shown for simplicity, but the container 29 is a container that can accommodate one or all the optical fiber ribbons 5 in each optical fiber ribbon 5. 29 are provided. Since the lubricant 7 is applied immediately before each tape core 5 is stacked and stored in the groove 2, even if the tape core 5 is stacked and stored in the groove 2, there is no close contact, and the cable is bent. However, they can slide smoothly with each other. Here, in order for the optical fiber ribbon 5 to be housed in the groove 2 at a fixed angle from the position of each bobbin 26, the rotation direction of the feeding drum 21 and the winding drum 28 is determined when the spacer 3 is fed. The direction is opposite to the spiral direction of the groove 2, and the groove 2 is rotated at a speed corresponding to the spiral period. After the cable core 4 to which the presser winding tape 7 has been applied is wound around the winding drum 28, the sheath 9 is applied in another step.

The preferred embodiment of the optical fiber ribbon cable of the present invention has been described above. However, the present invention is not limited to the above embodiment, and as shown in the second embodiment, the void portion of the cable core is a tube. Is also good.

(Embodiment 2) In Embodiment 2, a description will be given of a tape core type optical cable in which a void portion of a cable core is a tube and an optical fiber tape core is accommodated in the tube. FIG. 5 is a cross-sectional view showing a configuration of a tape type optical cable in which an optical fiber ribbon is accommodated in a tube. In FIG. 4, the optical fiber ribbon cable 10-1 has a plurality of optical fiber ribbons 5 stacked and housed in a polyester tube 13, and a lubricant 7 is interposed between the optical fiber ribbons 5. The space between the inner wall of the tube 13 and the optical fiber ribbon 5 is filled with the waterproof mixture 6, and the outer periphery of the tube 13 is covered with a low-density polyethylene sheath 9 having a built-in FRP strength member 1. It was formed as follows.

[0028] The optical fiber ribbon cable 10 of the present embodiment.
−1, by interposing a lubricant 7 such as talc between the optical fiber tape cores 5, the surface of the adjacent optical fiber tape cores 5 is kept in close contact or the friction is suppressed as much as possible. Even when the cable is bent, distortion is not concentrated, and a cable having stable transmission characteristics can be obtained.

Further, by interposing a waterproof mixture 6 mainly composed of α-olefin-based oil or the like between the inner wall of the tube 13 and the optical fiber tape core 5, the inner wall of the tube 13 and the optical fiber tape core are interposed. The waterproof mixture 6 prevents the lubricant 7 interposed between the optical fiber ribbons 5 from volatilizing, and the sliding effect can be stably maintained while the sliding with the wire 5 is improved.

FIG. 6 shows an optical fiber ribbon cable 10-1.
FIG. 1 is a schematic diagram showing a configuration of a manufacturing apparatus. This manufacturing apparatus includes a plastic extruder 3 for extruding a tube 13.
0, a supply device 31 for supplying the waterproof mixture 6, and a bobbin 26 for supplying the optical fiber 5. The plastic extruder 30 extrudes the polyester tube 13 around the outer circumference of the optical fiber tape 5 and the waterproof mixture 6 while inserting the same. In order to supply the optical fiber ribbon 5 drawn out from the bobbin 26 into the groove 2 with a predetermined tension, each of the optical fiber ribbons 5 is
6 through a tension adjusting dancer roller 27. The lubricant 7 is attached to the surface of the optical fiber ribbon 5 by passing it through a container 29 containing the lubricant 7 disposed immediately before being introduced into the extruder 30. The outer periphery of the tube 13 thus formed is covered with a cable sheath 9 containing the tensile strength member 1 in a separate step, and a tape-core optical cable 10-1 is manufactured.

Example A tape-core optical cable 10 according to Embodiment 1 having the structure shown in FIG. 1 was manufactured using the apparatus shown in FIG. 4, and the transmission loss due to bending of the obtained tape-core optical cable. Was measured. In FIG. 1, six grooves (1.5 mm wide, 2 m deep) are spirally formed in the longitudinal direction of the outer periphery of a tensile strength member 1 made of FRP having a diameter of 4 mm.
m), a spacer made of high-density polyethylene having a diameter of 10 mm was provided, and four optical fiber ribbons 5 were accommodated in each groove. A polyester holding tape 8 was applied to the outer periphery of the spacer 3, and a low-density polyethylene cable sheath 9 was provided on the outer periphery of the holding tape 8.

The optical fiber ribbon 5 has an outer diameter of 125 μm.
and four optical fiber strands 11 each of which is coated with a urethane acrylate UV curable resin having an outer diameter of 250 μm, are arranged in parallel on the outer periphery of an optical fiber mainly composed of silica glass of m. Coating layer 1 having a thickness of 0.4 mm and a width of 1.1 mm made of UV curable resin
2 are provided. As the waterproofing mixture 6, a mixture mainly composed of an α-olefin oil: daphne was used, and as the lubricant 7, talc: miphroace was interposed between the optical fiber tape cores 5.

The manufactured tape-core optical cable 10 is
The optical fiber was bent at a bending diameter of 200 mm, and a change in transmission loss due to bending was measured for 96 optical fibers. The increase in loss due to bending was 0.1 dB or less in all cases.

(Comparative Example) A tape type optical fiber cable was manufactured under the same conditions as in the example except that the lubricant 7 was not used, and a change in transmission loss due to bending was measured under the same conditions. Since there was a portion where the tape cores were in close contact with each other, the loss increase of the 88 optical fibers was 0.1 dB or less, but the loss increase of the eight optical fibers was 0.3 dB or more.

[0035]

According to the optical fiber ribbon of the present invention, the lubricant is interposed between the optical fiber ribbons, so that the surfaces between the optical fiber tapes adhere to each other or the friction is suppressed from increasing. Thus, even if the cable is bent, distortion is not concentrated, and a cable having stable transmission characteristics can be obtained. In addition, by interposing a waterproof mixture between the inner wall of the cable core gap and the optical fiber ribbon, the slip between the inner wall of the gap and the optical fiber ribbon is improved,
The waterproof compound prevents the lubricant interposed between the optical fiber tape cores from volatilizing and can stably maintain the sliding effect.

In the method of manufacturing the optical fiber ribbon cable according to the present invention, when introducing the optical fiber ribbon and the jelly-like waterproof mixture into the cable core void, the optical fiber tape is introduced into the void. Shortly before being made to adhere to the surface by passing it through the lubricant,
The lubricant can be easily and efficiently interposed between the optical fiber ribbons.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view showing a configuration of an embodiment of a tape-core optical cable according to the present invention, and FIG. 1B is an enlarged view of a groove portion.

FIG. 2 is a sectional view showing a configuration of an embodiment of an optical fiber ribbon used for the optical cable of the present invention.

FIG. 3 is a graph showing the relationship between the amount of lubricant added to the waterproofing mixture and the suggested heat.

FIG. 4 is a schematic diagram showing a configuration of an embodiment according to the optical cable manufacturing apparatus shown in FIG.

FIG. 5 is a cross-sectional view showing a configuration of another embodiment related to the optical fiber ribbon cable of the present invention.

FIG. 6 is a schematic diagram showing a configuration of an embodiment according to the optical cable manufacturing apparatus shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Tensile body, 2 ... Groove, 3 ... Spacer, 4 ... Cable core, 5 ... Optical fiber ribbon, 6 ... Waterproof mixture, 7 ... Lubricant, 8 ... Holding tape, 9 ... Cable sheath, 10-1 ... Tape core type optical cable,
11 ... optical fiber, 12 ... coating resin, 13 ... tube, 21 ... feeding drum, 22 ... guide nipple,
23 ... storage device, 24, 31 ... waterproof mixture supply device, 25 ... tape winding device, 26 ... bobbin, 27 ... dancer roller, 28 ... winding drum, 2 9 ... container,
30 ・ ・ ・ Plastic extruder

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Masakazu Watanabe 1 Tayacho, Sakae-ku, Yokohama-shi, Kanagawa, Japan Sumitomo Electric Industries, Ltd. Yokohama Works

Claims (4)

[Claims] 1. An optical fiber ribbon in which a plurality of optical fiber ribbons arranged in parallel are stacked and housed in a gap portion of a cable core, wherein the optical fiber tapes are connected to each other. Wherein a waterproof mixture is introduced between the inner wall of the gap and the optical fiber ribbon. 2. The waterproofing mixture according to claim 1, wherein the mixture is a mixture mainly composed of an α-olefin-based oil or a mixture mainly composed of a polybutene-based oil.
2. An optical fiber ribbon cable as described in 1. 3. The optical fiber ribbon cable according to claim 1, wherein the lubricant is talc, water-absorbing powder, or graphite powder. 4. The cable core is stretched and guided and twisted around its axis at a constant rotational speed, and then the optical fiber ribbon is accommodated in the gap of the cable core. A method for manufacturing a tape type optical fiber cable by providing a sheath, wherein a plurality of the optical fiber tape cores are stacked and housed in the gap portion, and a waterproof mixture is pressed into the gap portion, and further, the optical fiber tape core is formed in the gap. A method for manufacturing a tape-type optical fiber cable, wherein a lubricant is attached to the optical fiber ribbon just before being housed in the unit, and the lubricant is interposed between the optical fiber ribbons.