JP4811526B2 - 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 spacers (for example, high-density polyethylene) and the cable sheath (for example, low-density polyethylene) have the same thermoplastic resin density, 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. 3 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 coarsely wound string 5 in the rib part of the spacer 2, the rib part becomes a wall and the coarsely wound string 5 does not escape, so it is relatively easy to cut. Since the loosely wound string 5 straddles the cutter, it may not be cut.

  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, the coarsely wound string after cutting accumulates as fiber scraps, which entangles and prevents the presser winding tape 6 from being cut, entangles with the spacer 2, and closes the through hole of the die. It was.

  The present invention has been made in view of the above-described situation, and a coarsely wound string that prevents an optical fiber core wire from dropping from the groove of the spacer on the outer periphery of a grooved spacer that accommodates 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 applied to the outer periphery of the spacer. Is made of a fiber bundle and is bonded to a press-wound tape. Moreover, the said fiber bundle consists of fiber yarns whose melting | fusing point is 80 degreeC or more and 180 degrees C or less, and a polyamide resin can be used as a fiber yarn.

  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.

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 embodiment of this invention. It is a figure explaining the example of the spacer type cable with a groove | channel by a prior art.

  An embodiment of the present invention will be described with reference to FIGS. In the figure, 1 is an optical cable, 2 is a spacer, 2a is a groove, 3 is a tension member, 4 is an optical fiber core wire, 6 is a press-wrapping tape, 7 is a cable jacket, 8 is a coarse winding string, and 9a and 9b are fibers. The thread, 10 is the center, and 11 is the adhesive layer.

  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 in the optical cable manufacturing process, It is wound around the outer periphery. Further, a presser winding tape 6 and a cable jacket 7 are provided thereon.

  The conventional coarsely wound string 5 (see FIG. 3) 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, the press-winding tape 6 and the coarse winding cord 8 are integrated by using the rough winding cord 8 that is bonded to the press-winding tape 6, so that the optical cable can be easily disassembled. The fixing strength by the adhesion between the rough winding cord 8 and the presser winding tape 6 may be strong enough to maintain the adhesion between the two during the dismantling process. Therefore, the coarsely wound string 8 may be intermittently bonded to the presser winding tape 6 so as not to impair the workability during the dismantling process.

  FIG. 2A shows an example in which the coarsely wound string 8 according to the embodiment of the present invention is formed of a fiber bundle. In the present embodiment, a fiber bundle in which a large number of fiber yarns 9a and 9b are twisted is shown, but it need not be twisted. FIG. 2B is an example of the structure of individual fiber yarns 9 a constituting the coarsely wound string 8. The fiber yarn a has a two-layer structure, and the central portion 10 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. It is covered with an adhesive layer 11 made of a plastic material such as polyester, polyamide or polyurethane having a polar group.

  On the other hand, the fiber yarn 9b in FIG. 2 (C) is another example, 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. Is an example formed by the adhesive layer 11 of FIG. However, in the fiber yarn 9a of FIG. 2 (B), a material having high strength can be selected for the central portion 10, and therefore the structure of 9a is more preferable from the viewpoint of the strength of the fiber bundle.

  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.

  The coarsely wound string 8 is wound around the outer periphery of a grooved spacer 2 made of nonpolar plastic such as polyethylene, polypropylene, polystyrene, etc., and the presser wound tape 6 made of plastic such as polyester, polyamide, polyurethane or the like having a polar group thereon. Is given. The adhesive layer or the fiber yarn of the coarsely wound string 8 is melted by the resin extrusion temperature (180 ° C. to 220 ° C.) at the time of covering the cable jacket, and then solidified by cooling.

  At that time, the fiber bundle forming the coarsely wound string 8 is made of an adhesive layer made of a plastic such as polyester, polyamide or polyurethane having a polar group, or the fiber thread is pressed against a plastic made of polyester, polyamide or polyurethane having the same polar group. It is fused and integrated with the wound tape 6, but it is not fused and integrated with the grooved spacer 2 of nonpolar plastic such as polyethylene, 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 spacer 2 and the coarsely wound string 8 during the cable disassembly process.

  The coarsely wound string 8 shown as an embodiment is 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 lower. Therefore, it is not limited to the present embodiment, and for example, a tape-like woven fabric or non-woven fabric using fiber yarns 9a and 9b may be used.

  As an example of the implementation of the present invention, the center portion 10 of the fiber yarn 9a is a standard polyester having a melting point of 250 ° C., the adhesive layer 11 is a low melting point polyester having a melting point of 110 ° C., the grooved spacer 2 and the cable jacket 7 are polyethylene, By making the presser winding tape 6 a standard polyester having a melting point of 250 ° C., the adhesive layer 11 is melted by the heat (about 200 ° C.) when the cable jacket is extruded, and the presser winding tape 6 and the coarse winding cord 8 are bonded and fixed. On the other hand, the spacer 2 and the presser winding tape 6 can be structured not to adhere. As a result, the spacer 2 and the coarsely wound string 8 can be easily separated when the cable is disassembled.

DESCRIPTION OF SYMBOLS 1 ... Optical cable, 2 ... Spacer, 2a ... Groove, 3 ... Tension member, 4 ... Optical fiber core wire, 5 ... 8 Coarse winding string, 6 ... Pressing winding tape, 7 ... Cable jacket, 9a, 9b ... Fiber yarn 10 ... center part, 11 ... adhesive layer.

Claims (3)

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 is characterized in that the coarsely wound string is made of a fiber bundle and bonded to the presser wound tape.   The optical cable according to claim 1, wherein the fiber bundle is made of fiber yarn having a melting point of 80 ° C. or higher and 180 ° C. or lower.   The optical cable according to claim 2, wherein the fiber yarn is made of a polyamide resin.

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