JP4577302B2 - Optical cable - Google Patents

Description

  The present invention relates to an optical cable in which a large number of optical fiber cores are housed in a groove of a grooved spacer, and a rough winding string, a presser winding tape, and a cable jacket are sequentially applied to the outer periphery of the spacer.

  While the construction of large-capacity high-speed networks using optical cables has progressed, on the other hand, due to an increase in the amount of used optical cables discarded, measures for recycling optical cables are required from the viewpoint of global environmental protection and effective use of resources. In carrying out recycling of optical cables, various proposals have been made so far regarding optical cables considering recycling costs, quality of recycled products, and recycling.

  As a typical optical cable, a single-core or tape-shaped optical fiber core is housed in a groove of a grooved spacer, and a presser winding tape for heat insulation at the time of water stop or jacket forming is spirally wound around this outer periphery. Alternatively, there is a structure in which it is applied vertically and the outside is covered with a cable jacket. In the recycling of the optical cable, the cable jacket or the plastic material (usually polyethylene) of the spacer is targeted.

  For example, in Patent Document 1, when reusing a cable jacket, foreign matters such as a water-absorbing tape material can be removed at the stage of stripping the cable jacket, and the equipment and manner required for removing foreign matters at the regeneration stage are reduced. A dismantling method for achieving the above is disclosed. In this disassembling method, when the cable jacket is cut for peeling, it is cut with a thin skin so as not to reach the tape material in contact with the inner surface.

  Patent Document 2 discloses a method of smoothly peeling a tension member from the inside of the spacer body with a small peeling take-off force when the spacer is reused. In this method, after a slit for separation is cut into the spacer body, pressure is applied from the outer periphery to separate the tension member in an adhesive state from the spacer body. Next, only the tension member is inserted and pulled out from a guide hole provided in the inclined separation plate, and the spacer body is separated and disassembled so as to ride on the outer surface of the separation plate.

In Patent Document 3, when both the spacer and the cable sheath (cable jacket) are reused, an optical cable for efficiently recovering the resin material of the spacer and the cable sheath and reducing the cost of the recycling process is disclosed. Is disclosed. In this optical cable, the density of the thermoplastic resin of the spacer (for example, high-density polyethylene) and the cable sheath (for example, low-density polyethylene) is made comparable, and the spacer is pulled in accordance with the tensile strength (tension member) in the spacer. The tensile strength for tearing is embedded.
JP 2005-326656 A JP 2001-30193 A JP 2004-240061 A

  FIG. 5 is a diagram showing an example of an optical cable using a grooved spacer according to the prior art. As shown in the figure, a conventional optical cable 1 is composed of a spacer 2 made of a plastic material in which a tension member 3 is embedded and integrated at the center and a plurality of grooves 2a are provided. The groove 2a of the spacer 2 is formed in a spiral shape or SZ shape, and a plurality of optical fiber core wires or tape-like optical fiber core wires 4 are collected and accommodated in the groove 2a. In order to prevent the optical fiber core 4 from dropping out of the groove 2a (particularly in the case of an SZ spacer having an SZ-shaped groove) immediately after the optical fiber core 4 is housed in the groove 2a in the optical cable manufacturing process. The coarsely wound string 5 is spirally wound around the outer periphery of the spacer 2. The coarsely wound string 5 includes a tape-shaped one.

  On the outer periphery of the spacer 2 to which the coarsely wound string 5 is applied, presser winding tape 6 for water insulation in the cable or heat insulation at the time of forming the outer cover is applied by spiral winding or vertical attachment, and the outer side is outside the cable. The optical cable 1 is formed by covering with the cover 7. In the case of a spacer having a spiral groove, it is possible to prevent dropping of the optical fiber core wire with the press-wound tape 6 without using the coarse winding string 5, but in the case of a spacer having an SZ groove, In order to prevent the fiber from falling off, a plurality of optical fiber cores are collected and stored in the groove 2a of the spacer 2, and at the same time, it is difficult to apply the press-winding tape 6, and it is necessary to slow down the production line speed, which is not efficient. . For this reason, normally, when using an SZ spacer, the optical fiber core 4 is prevented from falling off by a rough winding string 5 made of a fiber bundle that can be easily wound around a point where a plurality of optical fiber cores 4 are accommodated. After that, the presser winding tape 6 is applied.

  As a dismantling method in the case of recycling the optical cable 1 described above, for example, as disclosed in Patent Document 1, the cable jacket 7 is cut with a cutter in the longitudinal direction, the jacket is removed and recovered, and then the cable A cut is made on the outer surface of the core with a cutter, the presser winding tape 6 and the coarsely wound string 5 are cut into chips, and the chips are removed with a die or the like. After the optical fiber is taken out from the spacer thus obtained, the tension member is separated from the spacer using, for example, a tension member peeling means as disclosed in Patent Document 2, and the spacer material is collected.

  In the presser roll removal during the recycling process described above, the presser wound tape 6 and the coarsely wound string 5 are cut by a cutter for removal. At this time, the presser winding tape 6 is a wide tape and has a certain amount of friction with the spacer, so that it can be cut in the longitudinal direction with a cutter or the like, but the coarsely wound string may remain without being cut. is there. The reason for this is that when the cutter hits the rough winding cord on the rib portion 2b of the spacer, the rib portion becomes a wall and the rough winding cord does not escape, so that it is relatively easy to cut, but the rough straddling the groove portion 2a of the spacer. The winding string may not be cut because it escapes to the cutter. Further, since the loosely wound string 5 with the end cut is loosened in a state where the tension is released, it may escape in the longitudinal direction of the spacer 2 without being cut even if it hits the cutter. Furthermore, there is a problem that the rough winding string after cutting accumulates as fiber scraps and becomes entangled to prevent the press winding tape from being cut, entangled with the spacer, or closes the through hole of the die.

  The present invention has been made in view of the above-described circumstances, and is a coarsely wound string that prevents the optical fiber core wire from dropping from the groove of the spacer on the outer periphery of the grooved spacer that houses a large number of optical fiber core wires. It is an object of the present invention to provide an optical cable capable of reliably and easily cutting and removing a coarsely wound string in a short time when dismantling the optical cable.

  An optical cable according to the present invention is an optical cable in which an optical fiber core wire is housed in a groove of a grooved spacer, and a rough winding string, a presser winding tape, and a cable jacket are sequentially provided on the outer periphery of the spacer. The winding string is bonded to the presser winding tape.

  According to the optical cable of the present invention, since the rough winding string is bonded and fixed to the presser winding tape, the rough winding string can be surely cut together with the presser winding tape. Moreover, since the coarsely wound string after cutting can be removed together with the presser tape, it does not become swarf and entangled with the spacer, etc., and the cable can be disassembled efficiently and in a shorter time. It becomes.

  An embodiment of the present invention will be described with reference to FIGS. In the figure, 1 is an optical cable, 2 is a grooved spacer, 2a is a groove, 3 is a tension member, 4 is an optical fiber core wire, 6 is a presser winding tape, 7 is a cable jacket, 8a, 8b, 8c, and 8d are rough. Indicates a winding string.

  As shown in FIG. 1, the optical cable 1 includes a spacer 2 made of a plastic material such as polyethylene, in which a tension member (also referred to as a strength member) 3 is embedded and integrated, and a plurality of grooves 2a are provided. The groove 2a of the spacer 2 is formed in a spiral shape or SZ shape, and a plurality of optical fiber core wires or tape-like optical fiber core wires 4 are accommodated in the groove 2a. In order to prevent the optical fiber core wire 4 from falling out of the groove 2a (especially in the case of the SZ spacer) after the optical fiber core wire 4 is housed in the groove 2a during the manufacturing process of the optical cable, the coarsely wound strings 8a, 8b, 8c, 8d is immediately wound around the outer periphery of the spacer 2. Further, a presser winding tape 6 and a cable jacket 7 are provided thereon.

  A conventional coarsely wound string 5 (see FIG. 5) is made of, for example, a bundle of fibers such as nylon and has a thickness of about 1260 denier. Further, in the case of an optical cable of about 100 cores and a spacer outer diameter of about 9 mm, the coarsely wound string 5 is formed by winding two strings at a pitch of 20 mm (with a pitch of 10 mm). Note that the conventional coarsely wound string 5 only needs to be held to such an extent that the optical fiber core wire 4 does not fall out of the groove 2a before the press winding tape 6 is applied. It is used.

  In the present invention, by using the coarse winding cords 8a, 8b, 8c, and 8d that are bonded to the presser winding tape 6, the presser winding tape 6 and the coarse winding cords 8a, 8b, 8c, and 8d are integrated to facilitate disassembly. A simple optical cable. The fixing strength between the rough winding cords 8a, 8b, 8c, and 8d and the presser winding tape 6 only needs to be strong enough to maintain the adhesion between the two during the dismantling process. Accordingly, the loosely wound strings 8a, 8b, 8c, and 8d may be intermittently adhered and fixed to the presser winding tape 6 so as not to impair the workability during the dismantling process.

  FIG. 2 shows a first embodiment of the present invention, which is an example in which the coarsely wound string 8a is formed of a tape-shaped flat string. The coarsely wound string 8a is composed of a base material portion 10 for ensuring the strength required for cable production, and an adhesive layer 9 for bonding and fixing the presser winding tape 6 and the coarsely wound string 8a. As the coarsely wound string 8a, for example, a plastic tape using an adhesive material such as acrylic, epoxy, or silicon as an adhesive layer is used. The coarsely wound string 8 a is applied to the outer periphery of the spacer 2 so that the base material portion 10 is on the lower side. Accordingly, the coarsely wound string 8a and the presser winding tape 6 are bonded and fixed by an adhesive force, while the spacer and the coarsely wound string are not bonded. As a result, it is possible to easily separate the spacer and the coarsely wound string during the cable disassembly process.

  In addition, by using a plastic material such as polyester, polyamide or polyurethane having a low melting point for the adhesive layer, the adhesive layer is melted by the heat of the extrusion coating process of the cable jacket and then cooled, so that it is roughened by heat fusion. The winding string 8a and the presser winding tape can be bonded and fixed. Since the resin temperature in the extrusion coating process of a cable jacket such as polyethylene that is generally used is 180 to 220 ° C., the adhesive layer needs to have a melting point of 180 ° C. or less. Note that if the melting point of the adhesive layer is too low, the rough winding string may be self-fused by the ambient temperature during storage of the rough winding string, so the lower limit is preferably 80 ° C. or higher. In general, since the same kind of plastic is easily heat-sealed, it is a more preferable form to use the same kind of plastic material for the adhesive layer of the coarsely wound string and the press winding tape.

  As an example, a standard polyester having a melting point of about 250 ° C. is used for the presser winding tape 6 and the base portion 10 of the rough winding cord 8a, and a low melting point polyester having a melting point of about 110 ° C. is used for the adhesive layer 9 of the rough winding cord 8a. Thus, in a normal coating process of polyethylene or the like, the press-wound tape and the coarse winding string can be reliably fused and integrated with heat (around 200 ° C.) at the time of cable jacket extrusion. In addition, since the polyester that does not melt at the extrusion temperature of the cable jacket is used on the surface of the rough winding string that contacts the spacer, the spacer and the rough winding string are not bonded, and therefore, when the cable is disassembled, Both can be easily separated.

  FIG. 3 (A) shows a second embodiment of the present invention, which is an example in which the coarsely wound string 8b is formed of a fiber bundle. In this embodiment, a twisted fiber bundle is shown, but twisting is not necessary. FIG. 3B is an example of the structure of the individual fiber yarns 11a and 11b constituting the coarsely wound string 8b. The fiber yarn 11a has a two-layer structure, and the central portion 12 is made of a plastic material having a melting point equal to or higher than the cable jacket extrusion temperature and has a melting point of 180 ° C. or lower, that is, a cable jacket extrusion temperature or lower. In addition, it is covered with an adhesive layer 13 made of a plastic material such as polyester, polyamide or polyurethane having a polar group. On the other hand, the fiber yarn 11b is another embodiment, and is a fiber yarn made of a plastic such as polyester, polyamide, or polyurethane having a melting point of 180 ° C. or less and having a polar group. In the fiber yarn 11a, a material having high strength can be selected for the central portion 12, and therefore the structure of 11a is more preferable from the viewpoint of the strength of the fiber bundle.

  FIG. 4 shows a third embodiment of the present invention, in which the coarsely wound strings 8c and 8b have a tape shape. The coarsely wound string 8c in FIG. 4 (A) has a two-layer structure, and the central portion 12 is made of a plastic material such as polyester, polyamide, or polyurethane having a melting point equal to or higher than the cable jacket extrusion temperature. That is, it is covered with the adhesive layer 13 made of a plastic material such as polyester, polyamide, or polyurethane having a melting point lower than the cable jacket extrusion temperature and having a polar group. On the other hand, the coarsely wound string 8d shown in FIG. 4B is another embodiment, and is a fiber yarn made of plastic such as polyester, polyamide, polyurethane, etc., all having a melting point of 180 ° C. or less and having a polar group. Also in this embodiment, since a material having high strength can be selected for the center portion 12, the structure of 8c is more preferable from the viewpoint of the strength of the fiber bundle.

  Coarse winding cords 8b, 8c, and 8d are wound around the outer periphery of a grooved spacer 2 made of nonpolar plastic such as polyethylene, polypropylene, and polystyrene, and a presser made of plastic such as polyester, polyamide, and polyurethane having a polar group thereon. A winding tape 6 is applied. By the resin extrusion temperature (180 ° C. to 220 ° C.) at the time of covering the cable jacket, the adhesive layer 13 of the coarsely wound string is melted and then solidified by cooling. At that time, the adhesive layer 13 of a plastic such as polyester, polyamide or polyurethane having a polar group is fused and integrated with a presser tape of a plastic such as polyester, polyamide or polyurethane having a polar group. It is not fused and integrated with grooved spacers of nonpolar plastics such as polypropylene and polystyrene. Therefore, the fusion target can be selected by utilizing the presence or absence of the polar group of the plastic material to be applied. As a result, it is possible to easily separate the grooved spacer and the coarsely wound string during the cable disassembly process.

  The coarsely wound strings 8b, 8c, 8d shown as the second and third embodiments are characterized in that at least the surface thereof is made of a plastic having a polar group and a melting point of 180 ° C. or less. . Therefore, it is not limited to a present Example, For example, the fiber yarn 11a, 11b is used for a loosely wound string as a single fiber, and the tape-like textile fabric or nonwoven fabric using the fiber yarn 11a, 11b is also contained. As an example of implementation according to this embodiment, the central portion 12 is a standard polyester having a melting point of 250 ° C., the adhesive layer 13 is a low melting point polyester having a melting point of 110 ° C., the grooved spacer and the cable jacket are polyethylene, and the presser winding tape has a melting point of 250 ° C. By using the standard polyester, the adhesive layer 13 is melted by the heat (about 200 degrees) when the cable jacket is extruded, and the presser winding tape and the rough winding cord are bonded and fixed, while the grooved spacer and the presser winding tape are used. Can have a structure that does not adhere. As a result, it is possible to easily separate the spacer and the coarsely wound string when the cable is disassembled.

It is a figure explaining the outline of the optical cable by this invention. It is a figure explaining the example of the rough winding string which concerns on the 1st Embodiment of this invention. It is a figure explaining the example of the rough winding string which concerns on the 2nd Embodiment of this invention. It is a figure explaining the example of the rough winding string which concerns on the 3rd Embodiment of this invention. It is a figure explaining the example of the spacer type cable with a groove | channel by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Optical cable, 2 ... Groove spacer, 2a ... Groove, 3 ... Tension member, 4 ... Optical fiber core wire, 5, 8a, 8b, 8c, 8d ... Coarse winding string, 6 ... Pressing winding tape, 7 ... Outside cable Cover, 9, 14 ... adhesive layer, 10 ... base material part, 11a, 11b ... fiber yarn, 12 ... center part, 13 ... adhesive layer.

Claims (5)

An optical cable in which an optical fiber core is housed in a groove of a grooved spacer, and a rough winding string, a presser winding tape, and a cable jacket are sequentially applied to the outer periphery of the spacer,
The optical cable, wherein the coarsely wound string is bonded to the presser winding tape.   The optical cable according to claim 1, wherein an adhesive layer is provided on a surface of the rough winding cord that is in contact with the presser winding tape.   The optical cable according to claim 2, wherein the adhesive layer of the coarsely wound string is made of a material that is heat-sealed with the presser wound tape at a temperature of 80 ° C. or more and 180 ° C. or less.   4. The optical cable according to claim 2, wherein the coarsely wound string has a tape shape, and an adhesive layer is provided only on a surface side in contact with the presser wound tape.   The grooved spacer is made of nonpolar plastic, the presser winding tape is made of plastic having a polar group, and the coarsely wound string has a polar group at least on its surface, and is at a temperature of 80 ° C. or more and 180 ° C. or less. The optical cable according to claim 1, wherein the optical cable is covered with a plastic that is heat-sealed with the presser winding tape.

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