JP4094630B2 - Single fiber separation method of optical fiber tape - Google Patents

Description

The present invention relates to an optical Faibate with integrated optical fiber single fibers is a plurality of parallel - the Puyunitto relates to a method for single-fiber separating optical fiber tape that is integrated by a plurality parallel middle section.

  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 home 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 home 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. A slot type optical cable is generally used in which a plurality of optical fiber tapes with a structure in which a plurality of single core wires are integrated are stacked and stored, a presser tape is wound around the outer periphery, and a jacket is provided on the tape. Yes. In such a cable, the optical fiber tape is connected to an optical drop cable or the like after being taken out from the SZ groove, or after being separated into single core wires (intermediate single core separation).

  By the way, in order to efficiently construct the FTTH network, it is necessary to effectively use the optical fiber of the optical fiber tape mounted on the cable. Therefore, an optical fiber that can be easily separated into a single optical fiber. Tape is sought. There is also a demand for further increase in the number of cores of the slot type optical cable.

  Therefore, in order to meet such a demand, a multi-fiber optical fiber tape can be easily divided into optical fiber tapes with a small number of cores as a connection unit. Optical fiber tape that can be easily separated into single cores, that is, an optical fiber that can be easily divided into optical fiber tapes with a small number of cores and separated into single optical fibers There is a growing need for tape.

  Optical fiber tapes that can be divided into optical fiber tapes with a small number of cores and separated into single optical fibers are optical fiber tapes in which a plurality of optical fiber single optical fibers are arranged in parallel and the outer periphery is covered with a primary tape layer. In addition, various types have been devised so far, such as those in which a plurality of sheets are arranged in parallel and a secondary tape layer is coated on the outer periphery thereof, and have been devised so far and are already put into practical use as split-type optical fiber tapes. (For example, refer to Patent Document 1).

  However, in the conventional split-type optical fiber tape, the tape layer is cut using a blade or a special shearing tool when it is split into a single-core optical fiber tape at the middle and further separated into single core wires. There is a risk that the optical fiber may be damaged or disconnected. Also, if there is a hot wire in a part of the single fiber in the optical fiber tape, transmission loss may increase due to inadvertent bending during work, leading to transmission errors. There is a problem that work is performed or an optical fiber tape without a live wire needs to be used, and work efficiency or use efficiency of the core wire is deteriorated.

  On the other hand, an optical fiber tape that can be easily separated by a single tool without using a blade or the like with a simple tool has been developed (for example, see Patent Documents 2 and 3). That is, this optical fiber tape is provided with brush pieces made of a wire material such as nylon on the upper and lower sides or one of them, and the brush pieces are repeatedly pressed against the upper and lower surfaces of the optical fiber tape, or in the pressed state, the optical fiber tape. The tape layer of the optical fiber tape is damaged or peeled off by moving it relatively in the length direction of the optical fiber, and separated into the optical fiber single fiber, easily and safely in the middle of the optical fiber single fiber In addition, since there is almost no increase in loss at the time of intermediate single-core separation, it is possible to perform intermediate single-core separation without stopping the line even for optical fiber tapes with live lines.

However, although this optical fiber tape can be easily separated into a single optical fiber, it is difficult to divide it into a few optical fiber tapes.
Japanese Patent Publication No. 7-36053 Japanese Patent No. 3664254 JP 2004-240014 A

  As mentioned above, in order to meet the demand for efficient construction of FTTH network and further increase in the number of optical cables, multi-fiber optical fiber tapes can be easily divided into small-fiber optical fiber tapes. Although there is an increasing need for an optical fiber tape capable of “easy” separation of the divided optical fiber tape into a single core wire, such an optical fiber tape has not yet been obtained.

The present invention has been made to deal with problems of the conventional art, division and how Ru can be easily performed the separation of the optical fiber single fiber to the core wire having a small number of optical fiber tapes The purpose is to provide.

In order to achieve the above object, the optical fiber tape single fiber separation method of the present invention has a thickness of 10 μm to 25 μm made of a resin having a Young's modulus at 23 ° C. of 500 MPa to 1100 MPa on the outer periphery of a plurality of optical fiber single fibers in parallel. A plurality of optical fiber tape units coated with the primary tape layer are juxtaposed in substantially the same direction as the arrangement direction of the optical fiber single wires, and the Young's modulus at 23 ° C. is 100 MPa to the outer periphery of these optical fiber tape units. A method for single- fiber separation of an optical fiber tape formed by coating a secondary tape layer having a thickness of 5 to 30 μm made of 400 MPa resin , wherein a flexible member is repeatedly pressed against the surface of the optical fiber tape, or By moving the optical fiber tape relatively several times in the length direction of the optical fiber tape in the pressed state, The next tape layer is damaged or removed, and the optical fiber tape is separated into optical fiber tape units (I), and the surface of at least one of the separated optical fiber tape units is rubbed with an abrasive. After the surface has been roughened, the flexible tape is repeatedly pressed against the portion or moved relatively in the length direction of the optical fiber tape unit a plurality of times with the flexible member being pressed. And (II) in which the layer is damaged or removed and separated into a single optical fiber .

  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 pulling speed of 1 mm / min.

According to the single-fiber separation method of the optical fiber tape of the present invention , it is possible to easily and safely divide the optical fiber tape unit into a small number of optical fiber tape units and to reduce the light without increasing transmission loss even if there is a live wire. Separation into single fiber can be performed.

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

FIG. 1 is a sectional view showing an 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 four optical fiber single-core wires 11 in close contact with each other on the same plane and is arranged in parallel. A tape unit 13 is formed, and two optical fiber tape units 13 are arranged in substantially the same plane, that is, in the same direction as the arrangement direction of the optical fiber single core wires 11, and these optical fiber tapes. The outer periphery of the unit 13 has a structure in which a secondary tape layer 14 is covered. The surfaces of the primary tape layer 12 and the secondary tape layer 14 are not substantially uneven, and the optical fiber tape unit 13 and the optical fiber tape 10 both 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 of 500 MPa or more at 23 ° C. so that the thickness (indicated by t1 in the figure) is in the range of 10 μm to 25 μm. The secondary tape layer 14 is covered with a resin having a Young's modulus at 23 ° C. of 400 MPa or less so that the thickness (indicated by t2 in the figure) is in the range of 5 μm to 30 μm.

  When the Young's modulus at 23 ° C. of the resin forming the primary tape layer 12 is less than 500 MPa, or the thickness t1 of the primary tape layer 12 is less than 10 μm, the optical fiber unit is divided into the optical fiber tape units 13. Separation of the core wire 11 occurs, and selective division into the optical fiber tape unit 13 becomes difficult. Further, when the thickness t1 of the primary tape layer 12 exceeds 25 μm, it becomes difficult to separate the optical fiber single core wire 11. Furthermore, even if the thickness t1 of the primary tape layer 12 is in the range of 10 μm to 25 μm, if the Young's modulus of the resin forming the primary tape layer 12 is too large, it is difficult to separate the optical fiber single core wire 11. Become. From such a viewpoint, the resin forming the primary tape layer 12 preferably has a Young's modulus at 23 ° C. of 500 MPa to 1100 MPa, and more preferably 700 MPa to 1100 MPa. The thickness t1 of the primary tape layer 12 is more preferably 15 μm to 25 μm.

  Further, when the Young's modulus at 23 ° C. of the resin forming the secondary tape layer 14 exceeds 400 MPa or the thickness t2 of the secondary tape layer 14 exceeds 30 μm, the optical fiber tape unit 13 is selectively used. Division becomes difficult. Moreover, if the thickness t2 of the secondary tape layer 14 is less than 5 μm, the function as an optical fiber tape cannot be maintained. Furthermore, even if the thickness t2 of the secondary tape layer 14 is in the range of 5 μm to 30 μm, if the Young's modulus of the resin forming the secondary tape layer 14 is too small, the function as an optical fiber tape is maintained. Becomes difficult. From such a viewpoint, the resin forming the secondary tape layer 14 preferably has a Young's modulus at 23 ° C. of 150 MPa to 400 MPa, and more preferably 150 MPa to 350 MPa. The thickness t2 of the secondary tape layer 14 is more preferably 5 μm to 20 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, ultraviolet curable resin, such as urethane acrylate resin and epoxy acrylate resin Etc.

  In the optical fiber tape 10 configured as described above, the plurality of optical fiber single core wires 11 arranged in parallel are made of a resin having a Young's modulus of 500 MPa or more at 23 ° C., and the thickness t1 is a primary tape of 10 μm to 25 μm. Further, a plurality of optical fiber tape units 13 configured as described above are arranged in parallel, are made of a resin having a Young's modulus at 23 ° C. of 400 MPa or less, and a thickness t2 is 5 μm. Since it is covered with the secondary tape layer 14 of ˜30 μm, it can be divided into optical fiber tape units and separated into single optical fibers very easily and safely. In addition, because there is little fluctuation in optical transmission loss when splitting into optical fiber tape units and separating into optical fiber single cores, the line is stopped even if there is a live line in the optical fiber tape to be separated. Separation work can be carried out without causing them. Therefore, it is possible to obtain a multi-core optical cable with a high core-wire usage rate using this.

  The example in which the present invention is applied to an eight-core optical fiber tape in which two four-fiber optical fiber tape units each having four optical fiber single-core wires are arranged in parallel has been described. Without being limited, as shown in FIGS. 2 to 4, a four-core optical fiber tape in which two two-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 20 shown in FIG. 2 replaces the four-fiber optical fiber tape unit 13 with two optical fiber single-core wires 11 in close contact with each other on the same plane. 1 and two optical fiber tape units 13a each having a two-core optical fiber coated with the primary tape layer 12 are arranged in parallel. The optical fiber tape 30 shown in FIG. 4 is an example in which three optical fiber tape units 13 are juxtaposed, and the optical fiber tape 40 shown in FIG. 4 has two optical fiber tape units 13a and four optical fibers in the embodiment shown in FIG. This is an example in which one fiber tape unit 13 is juxtaposed. Also in these optical fiber tapes 20 to 40, it is possible to divide into optical fiber tape units and separate into optical fiber single fibers very easily and safely, and in the optical fiber tape to be intermediately separated. Even when there is a live line, it is possible to perform separation work without stopping the line, and using this, it is possible to obtain an optical cable with a high core utilization rate and a multi-core.

  Although not shown, in the present invention, a resin or the like for forming the secondary tape layer 14 may be interposed between the adjacent optical fiber tape units 13 and 13a.

  Next, an example in which the optical fiber tape single-fiber separation method of the present invention is applied to single-fiber separation of the optical fiber tape 10 shown in FIG. 1 will be described.

In the present invention, as shown in FIG. 5, first, the optical fiber tape 10 is divided into optical fiber tape units 13 using a separating tool (step (I)).
That is, as shown in FIG. 6A, the optical fiber tape 10 is sandwiched between the upper base 61 and the lower base 62 of the separation tool 60, and is made of polyamide (nylon) or polypropylene standing upright on both the bases 61 and 62. The resulting wire 63 is brought close to the secondary tape layer 14 of the optical fiber tape 10. FIG. 6B is a cross-sectional view showing the state at that time. Further, when the separating tool 60 is pressed against the optical fiber tape 10, the wire 63 is bent as shown in FIG. 6C, and the tip of the bent wire 63 is in strong contact with the secondary tape layer 14 of the optical fiber tape 10. To do.

  In this state, the separation tool 60 is pressed against the optical fiber tape 10 and repeatedly moved relative to the length direction of the optical fiber tape 10 (the left-right direction in FIG. 6C). When it is repeatedly rubbed at 63, the secondary tape layer 14 is scratched or peeled off at the tip of the wire 63 to cause shaving or cracking, which further develops and breaks. As a result, the optical fiber tape 10 Are separated into optical fiber tape units 13. The wire 63 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 lightly rubbing about once or twice with a material to roughen the surface, an optical fiber single-core wire is used in substantially the same manner as in step (I), using a separation tool 60 similar to that used in step (I). 11 (step (II)).

  That is, the optical fiber tape unit 13 is sandwiched between the upper base 61 and the lower base 62 of the separating tool 60, and the wire 63 standing on both the bases 61 and 62 is pressed against the primary tape layer 12 of the optical fiber tape unit 13. When the separation tool 60 is pressed against the optical fiber tape unit 13 in this manner and is repeatedly moved relatively 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 63. 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 63 may be repeatedly pressed against the optical fiber tape unit 13 instead of being repeatedly moved relatively in the length direction of the optical fiber tape unit 13, and these may be combined as appropriate. You may do it.

  In such a method, it is very easy and safe to divide the optical fiber tape into optical fiber tape units, and further, the optical fiber tape unit thus divided can be separated into an optical fiber single fiber. it can. In addition, since there is almost no increase in the loss of the optical fiber, even if there is a live line in the optical fiber tape, the dividing and separating operations can be performed without stopping the line.

  Here, a description will be given of the results of experiments conducted for examining the splitting property of the split-type optical fiber tape into the optical fiber tape unit and the separability into the optical fiber single fiber by the above method.

  In the experiment, first, an optical fiber having an outer diameter (D) of 250 μm, in which a silica glass SM optical fiber having an outer diameter of 125 μm is coated with a urethane acrylate-based ultraviolet curable resin and further provided with a colored layer thereon. For the optical fiber tape unit in which four single core wires are juxtaposed on the same plane and the primary tape layer as shown in Tables 1 to 3 is formed, the above-mentioned step (II) (Abrasive (# 800 paper file) Then, the optical fiber tape unit is rubbed once each time, then sandwiched with a separating tool and repeatedly moved in the length direction of the optical fiber tape) to try to separate the optical fiber into a single optical fiber. Sex was evaluated. Further, the same method as the above method except that only the separating tool is used without using the abrasive, that is, the optical fiber tape unit is sandwiched between the separating tools and repeatedly moved in the length direction of the optical fiber tape unit, and the primary tape layer is formed. The rub resistance by the separation tool was examined. These evaluation results are also shown in Tables 1 to 3.

  The single-core separation property refers to the number of times the separation tool is moved on the tape layer after rubbing with an abrasive material before the single-core separation (the number of movements in one direction is counted as one time). It was evaluated based on the measured time (seconds) and the increase in transmission loss during separation (dB / km). Also, the rubbing resistance of the primary tape layer by the separating tool is determined by visually observing the state of the optical fiber tape unit after moving the separating tool repeatedly 30 times in the length direction of the optical fiber tape unit. Evaluation was made based on the presence or absence of peeling, shaving and single-core separation (separation).

  Also, among the optical fiber tape units, an optical fiber tape unit manufactured in the same manner as the optical fiber tape unit indicated by A-4-4 in Table 2 is used, and two of these optical fiber tape units are arranged in parallel on the same plane. For the optical fiber tape on which the secondary tape layer as shown in Table 6 was formed, the above-mentioned step (I) was applied to examine the division property into the optical fiber tape units. In addition, when manufacturing slot-type optical cables using these optical fiber tapes and storing the optical fiber tapes in the grooves, whether or not the secondary tape layer is peeled off or scraped and divided into optical fiber tape units is checked. It was examined visually. These evaluation results are also shown in Tables 4 to 6.

Incidentally, division of the optical fiber ribbon units (Unit dividable) is the number of times that the separating tool until separation is moved over the tape layer (times), the time required for separation (sec.), And transmission of the time separation Evaluation was based on the loss increase (dB / km).

  As is apparent from the above experimental results, when the primary tape layer is formed of a resin having a thickness of 10 μm to 25 μm and a Young's modulus at 23 ° C. of 500 MPa or more, the single-core separation property is good, and The rubbing resistance by the separating tool is also good or almost good. Further, when the secondary tape layer is formed of a resin having a thickness of 5 μm to 30 μm and a Young's modulus at 23 ° C. of 400 MPa or less, the separability to the optical fiber tape unit is good and the cable is formed. At this time, peeling and scraping of the secondary tape layer and division (separation) into optical fiber tape units hardly occur, and the function as an optical fiber tape is maintained.

  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 called a so-called slot-type optical cable suitable for use as a wiring cable for a subscriber optical wiring network. As shown in the figure, a steel wire, FRP (fiber reinforced plastic), etc. Polyethylene, etc., in which a plurality of (in the example of the drawing, 5) SZ-twisted grooves (SZ grooves) 72 extending in the longitudinal direction are provided at substantially equal intervals in the circumferential direction. The slot rod 73 which consists of is provided. 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 multi-fiber slot type optical cable with a high core wire usage rate.

  Next, examples of the present invention will be described, but the present invention is not limited to the following examples.

Example An optical fiber single fiber with 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-based UV-curable resin and further provided with a colored layer thereon. Are coated on the same plane with a urethane acrylate UV curable resin having a Young's modulus (23 ° C.) of 1000 MPa on the outer periphery and cured to form a primary tape layer having a thickness (t1) of 20 μm. A four-fiber optical fiber tape unit having a width of 1.1 mm and a thickness (T1) of 290 μm was manufactured.

  Next, while the obtained optical fiber tape units are arranged in parallel on the same plane, a urethane acrylate ultraviolet curable resin having a Young's modulus (23 ° C.) of 220 MPa is coated on the outer periphery and cured to obtain a thickness (t2 ) A 10 μm tape layer was formed, and an 8-fiber optical fiber tape having a width of 2.2 mm and a thickness (T2) of 310 μm was manufactured.

  Thereafter, an optical cable shown in FIG. 7 was manufactured using the obtained optical fiber tape. That is, five SZ grooves 72 (depth 2 mm) extending in the length direction are provided on the outer circumference, and a polyethylene having a diameter of 7.7 mm, in which a tensile body 71 made of a single steel wire having a diameter of 2.0 mm is embedded in the center. Each of the optical fiber tapes is stacked and stored in each SZ groove 72 of the made slot rod 73, and the presser tape is wound around the outside, and a tear string 77 is vertically attached to the extruder, Then, the outer periphery thereof was extrusion coated with polyethylene to produce a slot type optical cable having an outer diameter of about 12.5 mm.

  For the above optical fiber tape, the initial transmission loss (maximum) was measured, and the increase in transmission loss (maximum) after holding for 3 days at a temperature of 70 ° C. and humidity of 95% RH and after holding for 14 days in hot water at a temperature of 60 ° C. The increase (maximum) in transmission loss was measured, and the wet heat characteristics and hot water characteristics were evaluated. Further, for the slot type optical cable, the initial transmission loss (maximum) is measured, and the increase amount (maximum) of the transmission loss after being held for 3 cycles in the temperature range of −30 ° C. to + 60 ° C. is measured. Evaluated. These evaluation results are shown in Table 7.

  As is clear from the above results, the optical fiber tape and the slot type optical cable obtained in the examples both have high reliability.

It is sectional drawing which shows one Embodiment of the optical fiber tape of this invention. It is sectional drawing which shows the other example of the optical fiber tape of this invention. It is sectional drawing which shows the other example of the optical fiber tape of this invention. It is sectional drawing which shows the other example of the optical fiber tape of this invention. It is a figure explaining the single fiber separation method of the optical fiber tape of the present invention. It is a figure which shows typically the process I in the single core separation method of the optical fiber tape shown in FIG. It is sectional drawing which shows an example of the optical cable using the optical cable of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 20, 30, 74 ... Optical fiber tape, 11 ... Optical fiber single core wire, 12 ... Primary tape layer, 13, 13a ... Optical fiber tape unit, 14 ... Secondary tape layer, 60 ... Separation tool, 63 ... Wire , 70 ... Optical cable, 72 ... SZ groove, 73 ... Slot rod

Claims (2)

An optical fiber tape unit in which a primary tape layer having a thickness of 10 μm to 25 μm made of a resin having a Young's modulus at 23 ° C. of 500 MPa to 1100 MPa is coated on the outer periphery of a plurality of optical fiber single fibers arranged in parallel. A plurality of sheets are juxtaposed in substantially the same direction as the arrangement direction, and the outer periphery of these optical fiber tape units is coated with a secondary tape layer having a thickness of 5 μm to 30 μm made of a resin having a Young's modulus at 23 ° C. of 100 MPa to 400 MPa. A method of separating optical fiber tape from a single core ,
The flexible tape is repeatedly pressed against the surface of the optical fiber tape, or the secondary tape layer of the portion is damaged by moving the flexible member a plurality of times in the length direction of the optical fiber tape with the flexible member pressed against the surface. Or removing the optical fiber tape into an optical fiber tape unit (I) and roughening the surface of at least one of the separated optical fiber tape units by rubbing the surface with an abrasive. Thereafter, the flexible member is repeatedly pressed against the part, or the primary tape layer of the part is damaged by moving the flexible member a plurality of times in the length direction of the optical fiber tape unit while being pressed against the part. And a step (II) of separating the optical fiber tape into a single optical fiber. Single core separation method of the optical fiber ribbon of claim 1, wherein the abrasive is an abrasive paper or abrasive cloth.

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