JP4850732B2 - Optical fiber tape and optical cable - Google Patents

Description

  The present invention relates to an optical fiber tape that can be easily divided and separated into an optical fiber tape unit with a small number of cores in the middle of the cable and from the optical fiber tape unit into a single core wire, and such an optical fiber tape. The present invention relates to an optical cable using an optical fiber.

  In recent years, with the spread of communication services such as the Internet, FTTH (Fiber To The Home) that connects all sections from a communication carrier to a general subscriber's house with an optical fiber is rapidly expanding. In such FTTH, the optical wiring network in the vicinity of the subscriber's house is generally an overhead wiring using a power pole, and the main method is to drop the wiring cable from the wiring pole to the subscriber's house using an optical drop cable. Has been adopted.

  The wiring cable is provided with a plurality of SZ grooves on the outer periphery of the slot rod from the viewpoint of easy connection between the cables and removal of the optical fiber core at the time of intermediate branching. An optical fiber tape having a structure in which a plurality of single core wires are arranged in parallel and covered with a tape layer, or a structure in which such an optical fiber tape is made into one unit and a plurality of such units are arranged in parallel and covered with a tape layer. A slot-type optical cable is generally used in which a plurality of so-called split type optical fiber tapes are stacked and stored, a presser tape is wound around the outer periphery thereof, and a jacket is provided thereon. In such a cable, after the optical fiber tape or the split-type optical fiber tape is taken out from the SZ groove, it is separated into single cores or units, and then the separated single cores or units are directly or other wiring cables. By connecting to the optical drop cable via the cable, it is pulled down to the subscriber's house.

  By the way, for efficient construction of the FTTH network, it is important that the optical fiber in the optical fiber tape mounted on the optical cable is effectively used. For this reason, as the optical fiber tape to be accommodated in the slot type optical cable, among the above-mentioned optical fiber tapes, in particular, the latter divided optical fiber tape, that is, the optical fiber tape divided into a small number of optical fiber tapes (optical fiber tape units) There is an increasing need for a split-type optical fiber tape that has both functions of separation into a single optical fiber.

  However, in the conventional split type optical fiber tape, it is necessary to use a knife or a special shear type tool for dividing or separating into units or single core wires, and the workability is not good. There was a problem that it could not be used effectively. That is, these tools may damage or break the optical fiber if used incorrectly. For this reason, an unused optical fiber tape in an optical cable may be cut together with the optical fiber tape without performing an intermediate dividing and separating operation, and only one core of a plurality of optical fiber single core wires may be pulled down. . In this case, the usage rate of the core wire decreases. In addition, when a part of the single-core wire in the optical fiber tape has a hot wire, there is a possibility that transmission loss increases due to careless bending at the time of operation, resulting in a transmission error. In this case, it is necessary to work after the line is temporarily stopped, or it is necessary to use an optical fiber tape without a live line, so that the work efficiency or the utilization rate of the core is lowered.

  On the other hand, an optical fiber tape that can be easily separated into single cores with a simple tool without using a blade or the like has also been developed (see, for example, Patent Document 1). That is, this optical fiber tape uses a tool having a brush piece made of a wire material such as nylon on the upper and lower sides or one of them, and repeatedly presses the brush piece on both upper and lower sides of the optical fiber tape, or in a pressed state. By moving relative to the length of the optical fiber tape, the tape layer of the optical fiber tape can be damaged or peeled off and separated into a single optical fiber. In addition, it is possible to safely perform intermediate separation into a single optical fiber. In addition, since there is almost no increase in loss at the time of intermediate single-core separation, intermediate single-core separation is also possible without temporarily stopping the line for optical fiber tapes with live wires.

However, although this optical fiber tape can be easily separated into optical fiber single core wires, it is difficult to divide the optical fiber tape into optical fiber tapes with a small number of cores.
Japanese Patent Laid-Open No. 2004-206048

  The present invention has been made in response to such a problem of the prior art, and can be easily divided into an optical fiber tape (optical fiber tape unit) with a small number of cores at the middle portion of the cable. An optical fiber tape that can easily separate an optical fiber tape with a small number of optical fibers into a single optical fiber, and an optical cable that can improve the efficiency of use of the optical fiber by using such an optical fiber tape The purpose is to do.

In order to achieve the above object, an optical fiber tape of the present invention comprises an optical fiber tape unit in which a plurality of optical fiber single fibers are juxtaposed and a primary tape layer is coated on the outer periphery thereof. An optical fiber tape in which a plurality of sheets are juxtaposed in substantially the same direction, and a secondary tape layer is coated on the outer periphery thereof, and the surface of the secondary tape layer is repeatedly rubbed or pressed with a flexible wire. The surface of the primary tape layer of the separated optical fiber tape unit is roughened by rubbing with an abrasive material, and the roughened surface is repeated with a flexible wire. The optical fiber tape separated into the optical fiber single fibers by rubbing or pressing satisfies the following requirements (a) to (f). It is a sign.
(A) The primary tape layer is made of a resin having a thickness of 5 to 10 μm and a Young's modulus at 23 ° C. of 700 to 1100 MPa. (B) The secondary tape layer has a thickness of 10 to 25 μm and 23 (C) Only the primary tape layer and the secondary tape layer are coated on the outer periphery of each optical fiber single core wire. (D) Inside the optical fiber tape unit. (E) Adjacent optical fiber tape units are in contact with each other (f) The optical fiber tape and each optical fiber tape unit are both in the width direction. it is substantially uniform thickness

  The optical cable of the present invention is characterized by comprising the optical fiber tape.

  In the present specification, the Young's modulus is a value measured in accordance with JIS K 7113. More specifically, a test piece made of a resin sheet and molded into a JIS No. 2 dumbbell is used. The Young's modulus obtained by pulling under conditions of a distance between marked lines of 25 mm and a tensile speed of 1 mm / min.

  According to the optical fiber tape of the present invention, from a multi-fiber optical fiber tape to a small-fiber optical fiber tape unit, easily and safely, and without greatly increasing transmission loss even when there is a live wire, The optical fiber tape unit having a small number of cores can be divided and separated into a single optical fiber, and an optical cable with a high utilization rate of the core can be obtained using this.

  Further, according to the optical cable of the present invention, it is possible to provide an optical fiber tape excellent in the ability to divide into such a small number of optical fiber tape units and in the separation property into an optical fiber single fiber. The usage rate can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a first embodiment of the optical fiber tape of the present invention.

  As shown in FIG. 1, the optical fiber tape 10 of the present embodiment has two optical fiber single-core wires 11 in close contact with each other on the same plane and arranged in parallel. A unit 13 is formed, and two optical fiber tape units 13 are arranged in substantially the same plane, that is, in close contact with each other in the same direction as the arrangement direction of the optical fiber single-core wires 11, and these optical fibers are connected in parallel. The outer periphery of the fiber tape unit 13 has a structure in which the tape layer 14 is collectively covered. Hereinafter, the tape layer 12 coated on the optical fiber core 11 is referred to as a primary tape layer, and the tape layer 14 coated on the optical fiber tape unit 13 is referred to as a secondary tape layer. The surfaces of the primary tape layer 12 and the secondary tape layer 14 are not substantially uneven, and both the optical fiber tape unit 13 and the optical fiber tape 10 have a substantially uniform thickness in the width direction. ing.

  As the optical fiber single core wire 11, for example, an optical fiber provided with a protective coating of one or a plurality of layers by an ultraviolet curable resin or the like, or a colored layer provided on such a protective coating. used.

On the other hand, the primary tape layer 12 is coated with a resin having a Young's modulus at 23 ° C. of 700 to 1100 MPa so that the thickness (indicated by t ₁ in the figure) is in the range of 5 to 10 μm. The secondary tape layer 14 is covered with a resin having a Young's modulus of 20 to 70 MPa at 23 ° C. so that the thickness (indicated by t ₂ in the figure) is in the range of 10 to 25 μm. Here, as shown in FIG. 1, the thickness of the primary tape layer 12 is the surface parallel to the parallel direction of the common tangent S ₁ of the optical fiber single core wire 11 and the optical fiber single core wire 11 of the primary tape layer 12. Distance t ₁ and can be calculated by t ₁ = (T ₁ −d) / 2. Further, as shown in FIG. 1, the thickness of the secondary tape layer 14 is defined between the surface parallel to the parallel direction of the common tangent S ₂ of the optical fiber tape unit 13 and the optical fiber single core wire 11 of the optical fiber tape 10. The distance t ₂ can be obtained by t ₂ = (T ₂ −d) / 2. In the above formula, T ₁ is the maximum thickness of the optical fiber tape unit 13, d is the outer diameter of the optical fiber single core wire 11, and T ₂ is the maximum thickness of the optical fiber tape 10.

The Young's modulus at 23 ° C. of the resin forming the primary tape layer 12, the thickness t ₁ of the primary tape layer 12, the Young's modulus at 23 ° C. of the resin forming the secondary tape layer 14, and the thickness of the secondary tape layer 14 If any one of the lengths t ₂ is out of the above range, it is difficult to divide the optical fiber tape unit 13 or to separate the optical fiber tape unit 13 from the optical fiber single-core wire 11. There is a risk. In the present invention, in view of the balance of various characteristics, more preferably, the Young's modulus at 23 ° C. of the resin forming the primary tape layer 12 is 800 to 1000 MPa, and the thickness t ₁ of the primary tape layer 12 is 7 to ₁₀ μm. is there. On the other hand, the Young's modulus at 23 ° C. of the resin forming the secondary tape layer 14 is 30 to 50 MPa, and the thickness t ₂ of the secondary tape layer 14 is 15 to 25 μm.

  In addition, as a kind of resin which comprises the protective coating and colored layer of the optical fiber single core wire 11, and the primary tape layer 12 and the secondary tape layer 14, it is ultraviolet curing type, such as urethane acrylate resin and epoxy acrylate resin Although resin is illustrated, it is not particularly limited to these.

  Next, an example of a method of dividing the four-fiber optical fiber tape 10 into optical fiber tape units 13 and further separating the divided optical fiber tape unit 13 into optical fiber single core wires 11 will be described.

  First, as shown in FIG. 2, the optical fiber tape 10 is divided into optical fiber tape units 13 using a separating tool (step (I)).

  This step is performed using a separation tool 30 as shown in FIG. That is, as shown in FIG. 3 (A), a wire 33 made of polyamide (nylon), polypropylene, or the like, which is sandwiched between the upper base 31 and the lower base 32 of the separation tool 30 and is erected on both the bases 31 and 32, Move closer to the fiber tape 10. FIG. 3B is a cross-sectional view showing the state at that time. Next, when the separating tool 30 is pressed against the optical fiber tape 10, the wire 33 is bent as shown in FIG. 3C, and the tip of the bent wire 33 is strong with the secondary tape layer 14 of the optical fiber tape 10. Contact. In this state, the separation tool 30 is pressed against the optical fiber tape 10 and is relatively repeatedly moved in the length direction of the optical fiber tape 10 (left and right direction in FIG. 3C). When repeatedly rubbing at 33, the secondary tape layer 14 is scratched or peeled off at the tip of the wire rod 33, causing shaving or cracks to develop and break down. As a result, the optical fiber tape 10 The optical fiber tape unit 13 is separated. The wire 33 may be repeatedly pressed against the optical fiber tape 10 instead of being relatively repeatedly moved in the length direction of the optical fiber tape 10, or may be appropriately combined. .

  Next, one or both surfaces of the divided optical fiber tape unit 13, that is, one or both of the surfaces parallel to the arrangement surface of the optical fiber single core wires 11 of the primary tape layer 12 are polished like a polishing paper or a polishing cloth. After rubbing the surface lightly about once or twice with a material, the optical fiber single core wire 11 is formed in substantially the same manner as in the step (I) by using the separation tool 30 similar to that used in the step (I). Separate (step (II)).

  That is, the optical fiber tape unit 13 is sandwiched between the upper base 31 and the lower base 32 of the separation tool 30, and the wire 33 standing on both the bases 31 and 32 is pressed against the primary tape layer 12 of the optical fiber tape unit 13. When the separation tool 30 is pressed against the optical fiber tape unit 13 in this manner and moved relatively repeatedly in the length direction of the optical fiber tape unit 13, the primary tape layer 12 is damaged or peeled off at the tip of the wire 33. As a result, scraping or cracks are generated, and further, this progresses and breaks. As a result, the optical fiber tape unit 13 is separated into the optical fiber single core wires 11. In this case as well, the wire rod 33 may be repeatedly pressed against the optical fiber tape unit 13 instead of being relatively moved repeatedly in the length direction of the optical fiber tape unit 13, and these are appropriately combined. You may do it.

  As described above, in the optical fiber tape 10 of the present embodiment, the optical fiber tape unit 13 is easily and safely divided into the optical fiber tape units 13, and the divided optical fiber tape units 13 are easily formed into the optical fiber single core wire 11. And can be separated safely. Further, since there is little fluctuation in optical transmission loss during the division into the optical fiber tape unit 13 and the separation work into the optical fiber single core wire 11, even when there is a live line in the optical fiber tape 10 to be intermediately separated, Separation work can be performed without stopping the line. Therefore, it is possible to obtain an optical cable with a high use rate of the core wire by using this.

  Here, it describes about the experimental result performed in order to investigate the splitting property to the optical fiber tape unit of the optical fiber tape of this embodiment, and the isolation | separation property to an optical fiber single core wire.

In the experiment, first, an optical fiber having an outer diameter (d) of 250 μm, in which a silica glass-based SM optical fiber having an outer diameter of 125 μm is coated with a urethane acrylate ultraviolet curable resin and a colored layer is further provided thereon. While two single core wires are juxtaposed on the same plane, the outer circumference is coated with a urethane acrylate ultraviolet curable resin having a Young's modulus (23 ° C.) of 600, 700 MPa, 1000 MPa, 1100 MPa, or 1200 MPa, and cured. (T ₁ ) A primary tape layer of 5 μm, 10 μm, 20 μm or 30 μm was formed to manufacture a two-fiber optical fiber tape unit.

Next, two optical fiber tape units obtained were placed side by side on the same plane, and the outer periphery was coated with a urethane acrylate ultraviolet curable resin having a Young's modulus (23 ° C.) of 10 MPa, 20 MPa, 40 MPa, 70 MPa, or 200 MPa. By curing, a secondary tape layer having a thickness (t ₂ ) of 5 μm, 10 μm, 15 μm, 25 μm, or 30 μm was formed, and a four-core optical fiber tape was manufactured.

  The obtained four-core optical fiber tape is divided into optical fiber tape units by applying the method described with reference to FIG. 2, and further, an attempt is made to separate the divided optical fiber tape unit into a single optical fiber. Separability into tape units (unit division) and separation into optical fiber single fibers (single fiber separation) were evaluated. In addition, a slot-type optical cable is manufactured using the obtained optical fiber tape, and the change in the appearance of the optical fiber tape when the optical fiber tape is stored in the SZ groove, that is, peeling or scraping of the secondary tape layer and the optical fiber The presence or absence of division (separation) into tape units was examined.

  In the step (I) of dividing the optical fiber tape into optical fiber tape units, a method was used in which the optical fiber tape was sandwiched between separation tools and the separation tool was repeatedly moved in the length direction. Also, in the step (II) of separating the optical fiber tape unit from the optical fiber single core wire, both sides of the optical fiber tape unit are rubbed once with an abrasive (# 800 paper file) and then sandwiched with a separating tool. A method of repeatedly moving the optical fiber tape unit in the length direction was used. Further, in the evaluation method, the unit splitting property is determined by the number of times the separation tool is moved on the tape layer before the optical fiber tape is divided into the optical fiber tape units (the movement in one direction is counted as one time). The single-core separation property refers to the number of times the separation tool is moved on the tape layer after the optical fiber tape unit is separated into optical fiber single-core wires after rubbing with an abrasive (one movement in one direction is considered as one time). Count). Moreover, the microscope was used for observation of peeling and shaving of the secondary tape layer at the time of cable formation. These evaluation results are shown in Tables 1 to 5 together with the configurations of the primary tape layer and the secondary tape layer.

  The above experimental results show that the primary tape layer is formed of a resin having a Young's modulus at 23 ° C. of 700 MPa to 1100 MPa, and the secondary tape layer is formed of a resin having a Young's modulus at 23 ° C. of 20 MPa to 70 MPa. In this case, both unit splitting and single-core separation are good, and the secondary tape layer is not peeled off or scraped and split into optical fiber tape units during cable formation. In particular, the primary tape layer is formed of a resin having a thickness of 5 to 10 μm, a Young's modulus at 23 ° C. of 700 to 1100 MPa, and the secondary tape layer has a thickness of 10 When it is made of a resin having a Young's modulus at 23 ° C. of 20 to 70 MPa at ˜25 μm, it shows that good results can be obtained.

  The example in which the present invention is applied to a four-core optical fiber tape in which two two-fiber optical fiber tape units each having two optical fiber single fibers are arranged in parallel has been described. 4 to 6, as shown in FIG. 4 to FIG. 6, an 8-core optical fiber tape in which two four-fiber optical fiber tape units are arranged in parallel, and a 12-core light in which three four-fiber optical fiber tape units are arranged in parallel. The present invention can be widely applied to an 8-fiber optical fiber tape in which two fiber tapes, two two-fiber optical fiber tape units, and one four-fiber optical fiber tape unit are arranged in parallel.

  That is, in the embodiment shown in FIG. 1, the optical fiber tape 40 shown in FIG. 4 is replaced with four optical fiber single-core wires 11 in close contact on the same plane, instead of the two-fiber optical fiber tape unit 13. 5 is an example in which two four-fiber optical fiber tape units 13a covered with the primary tape layer 12 are juxtaposed, and the optical fiber tape 50 shown in FIG. This is an example in which sheets are arranged in parallel. Further, the optical fiber tape 60 shown in FIG. 6 is an example in which two optical fiber tape units 13 and one optical fiber tape unit 13a are arranged in parallel in the embodiment shown in FIG. These optical fiber tapes 40 to 60 can be easily and safely divided into optical fiber tape units and separated into single optical fiber fibers, and can be used in an optical fiber tape to be intermediately separated. Even when there is a line, separation work can be performed without stopping the line, and an optical cable with a high core wire usage rate can be obtained using this.

  Although not shown, in the present invention, a resin for forming the secondary tape layer 14 may be interposed between the adjacent optical fiber tape units 13 and 13a. In the units 13 and 13a, a resin forming the primary tape layer 12 may be interposed between the adjacent optical fiber single core wires 11. However, from the viewpoint of enhancing unit splitting and single-core separation, it is preferable that the adjacent optical fiber tape units 13 and 13a or the adjacent optical fiber single-core wires 11 are in close contact.

  Next, an optical cable using the optical fiber tape of the present invention will be described.

  FIG. 7 is a cross-sectional view showing an example of an optical cable using the optical fiber tape of the present invention.

  This optical cable 70 is a so-called slot-type optical cable suitable for use as a wiring cable for a subscriber optical wiring network. As shown in FIG. 7, a tensile strength body 71 made of steel wire, FRP (fiber reinforced plastic) or the like is embedded in the center, and a plurality of (5 in the example shown in the drawing) SZ strands extending in the length direction. A groove (SZ groove) 72 is provided with a slot rod 73 made of polyethylene or the like provided at substantially equal intervals in the circumferential direction. In each SZ groove 72 of the slot rod 73, a plurality of, for example, five optical fiber tapes 74 are stacked and accommodated. An outer jacket 76 is provided. The optical fiber tape 74 uses the above-described optical fiber tape of the present invention. In FIG. 7, reference numeral 77 denotes a tear string vertically attached to the outer jacket 76 in order to facilitate removal of the optical fiber tape 74.

  In such an optical cable 70, the optical fiber tape 74 can be divided into optical fiber tape units and an optical fiber single core extremely easily and safely without increasing transmission loss even if there is a live wire. Since an optical fiber tape that can be separated into wires is used, an efficient FTTH network can be constructed as a slot-type optical cable with a high core wire usage rate.

  The optical fiber tape of the present invention is not limited to the slot type optical cable as described above, but can be widely used for various conventionally known optical cables including a so-called slotless type optical cable, and the use rate of the cores is improved. Can be made.

It is sectional drawing which shows 1st Embodiment of the optical fiber tape of this invention. It is a figure explaining an example of the division | segmentation / separation method to the unit of the optical fiber tape of this invention, and a single core wire. It is a figure which shows the process I shown in FIG. 2 typically. It is sectional drawing which shows one modification of 1st Embodiment of the optical fiber tape of this invention. It is sectional drawing which shows the other modification of 1st Embodiment of the optical fiber tape of this invention. It is sectional drawing which shows the further another modification of 1st Embodiment of the optical fiber tape of this invention. It is sectional drawing which shows an example of the optical cable using the optical fiber tape of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 40, 50, 60, 74 ... Optical fiber tape, 11 ... Optical fiber single core wire, 12 ... Primary tape layer, 13, 13a ... Optical fiber tape unit, 14 ... Secondary tape layer, 70 ... Optical cable, 72 ... SZ groove, 73 ... slot rod

Claims (2)

A plurality of optical fiber tape units in which a plurality of optical fiber single fibers are arranged in parallel and a primary tape layer is coated on the outer periphery thereof are arranged in parallel in substantially the same direction as the arrangement direction of the optical fiber single fibers, An optical fiber tape coated with a secondary tape layer,
The surface of the secondary tape layer is separated into the optical fiber tape unit by repeatedly rubbing or pressing with a flexible wire, and the surface of the primary tape layer of the separated optical fiber tape unit is ground with an abrasive. In an optical fiber tape that is roughened by rubbing and separated into the optical fiber single core by repeatedly rubbing or pressing the roughened surface with a flexible wire,
An optical fiber tape characterized by satisfying the following requirements (a) to (f) :
(A) The primary tape layer is made of a resin having a thickness of 5 to 10 μm and a Young's modulus at 23 ° C. of 700 to 1100 MPa. (B) The secondary tape layer has a thickness of 10 to 25 μm and 23 (C) Only the primary tape layer and the secondary tape layer are coated on the outer periphery of each optical fiber single core wire. (D) Inside the optical fiber tape unit. (E) Adjacent optical fiber tape units are in contact with each other (f) The optical fiber tape and each optical fiber tape unit are both in the width direction. it is substantially uniform thickness   An optical cable comprising the optical fiber tape according to claim 1.

Images