JPH11256444A - Yarn for bunching optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent bundle from fastening due to yarn by minimizing elongation left in bunching yarn wound around optical fiber bundle to the utmost in a yarn for bunching used in optical fiber bundle. SOLUTION: Yarn obtained by applying <=100 times twist/m to plural filaments is used as yarn for bunching. A surface-treating agent such as an antistatic agent or a binder may be previously applied to the filament and elongation left in yarn for bunching after winding can further be made small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber bunching yarn used for an optical fiber bundle.

[0002]

2. Description of the Related Art A plurality of optical fibers such as an optical fiber, an optical fiber core, an optical fiber tape core, and an optical fiber unit are twisted or bundled and assembled, and a bunching yarn is wound around the assembly. A fiber bundle is used as an optical unit of an optical cable. Conventionally, as the bunching yarn, a spun yarn (spun yarn) obtained by twisting short fibers such as cotton and chemical fibers or a filament obtained by simply aligning and bundling long fibers has been used.

[0003] Spun yarns are twisted at an extremely short pitch, for example, about 800 to 1200 times per meter in order to twist short fibers into one long yarn. However, this spun yarn has a characteristic of exhibiting a large elongation with an extremely small tension due to the return of twist when a tensile force is applied. For example, with 200 denier cotton yarn,
It exhibits an elongation of 1.2% at a tension of 50 g. For this reason, when wound around an optical fiber, the tension of the spun yarn sent from the cheese is reduced as much as possible, and the spun yarn is sent out while reducing the amount of shrinkage of the yarn after winding, so that the optical fiber bundle is not tightened by the bunching yarn. You need to do that.

[0004] Further, when a filament obtained by bundling long fibers is used as a bunching yarn, there is a problem that the filament is easily divided into elementary fibers at the time of winding and the yarn is frayed. Furthermore, any type of bunching yarn has a property of causing heat shrinkage when heated to a high temperature of 50 ° C. or more, and when an optical cable using an optical fiber bundle is exposed to such a temperature, the bunching yarn is used. There is also a problem that the yarn contracts and tightens the optical fiber bundle.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the amount of shrinkage of the bunching yarn without reducing the yarn sending tension, and to prevent the optical fiber bundle from being tightened. Another object of the present invention is to prevent the yarn from being split into elementary fibers when the bunching yarn is wound and not frayed. Another object of the present invention is to prevent the bunching yarn from thermally shrinking even when exposed to high temperatures.

[0006]

According to the present invention, a yarn obtained by adding 100 or less twists per meter to a plurality of long fiber filaments is used as a bunching yarn, so that the yarn can be shrunk without reducing the feeding tension. The amount can be reduced,
Further, it is possible to prevent the yarn from fraying during winding. Also, by applying a surface treatment agent such as an antistatic agent and a sizing agent to the long fiber filament, the yarn for bunching can be smoothly sent out of the cheese, and the sending tension can be reduced, and the shrinkage can be reduced. it can. Furthermore, by performing the heat treatment at 60 to 100 ° C. in advance, when the optical cable or the like is used, the bunching yarn does not thermally shrink even when exposed to high temperatures.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The bunching yarn according to claim 1 of the present invention is a yarn obtained by applying a twist of 100 or less per m to a plurality of long fiber filaments. The long fiber filament used here refers to a filament having a thickness of 50 to 1000 denier of a chemical fiber such as nylon or polyester. After bundling many of these filaments,
A yarn obtained by adding a weak twist of 100 times or less, preferably 40 to 80 times per m is the bunching yarn. Twisting may be either S-twisting or Z-twisting. here,
If the number of twists exceeds 100 per meter, the amount of shrinkage of the bunching yarn after winding becomes large, which is inconvenient.
In this bunching yarn, for example, a polyester yarn 25
The elongation at a 0-denier tensile force of 50 g is 0.15%. This yarn is wound on a winding bobbin to form a cheese, which is then used.

In such a bunching yarn, since the number of twists is small and the twist is weak, the elongation remains at a low level even if the tensile force acting on the yarn increases. For this reason, even if the feeding tension at the time of winding of the bunching yarn is not reduced, the elongation remaining on the yarn after winding is small and the shrinkage amount is small. Will not be tightened. In addition, since an appropriate twist is added, the fibers are not separated into elementary fibers, and the yarns are not frayed.

The bunching yarn according to the second aspect of the present invention is the bunching yarn according to the first aspect, wherein a surface treatment agent such as an antistatic agent or a sizing agent is applied to the surface of the long fiber filament, and then this is applied. It is made by bundling and twisting. As the antistatic sizing agent, an anionic or cationic agent is used.

In this bunching yarn, the slipperiness of the surface of the yarn is improved, and the yarn can be smoothly fed out of the cheese, whereby the feeding tension can be reduced. For this reason, it is possible to further reduce the shrinkage amount of the wound yarn as compared with the bunching yarn according to the first aspect.

The bunching yarn according to claim 3 of the present invention is the bunching yarn according to claim 1, wherein
Heat treatment at a temperature of 00 ° C. is further performed. This heat treatment causes the yarn to shrink by about 1 to 10%. The heat treatment here is preferably performed at a temperature of 60 to 100 ° C. for a time of 0.1 to 6 hours in a non-oxidizing atmosphere.

In the bunching yarn, when the optical fiber bundle manufactured by winding the bunching yarn is used for an optical cable, the optical cable has a length of 60 to 100.
Even if a heat history of ° C. is applied, the bunching yarn does not thermally contract due to this heat history. For this reason, the optical fiber bundle in the optical cable is not fastened by the bunching thread, and the transmission loss of the optical fiber can be prevented from increasing.

[0013]

As described above, according to the first aspect of the present invention, the optical fiber bundle is not tightened by the bunching thread, and the transmission loss of the optical fiber does not increase. Also, no fraying occurs when winding the bunching yarn. According to the invention according to claim 2, the yarn for bunching can be further smoothly fed from the cheese, the feeding tension can be reduced, and the shrinkage of the bunching yarn can be further reduced. According to the third aspect of the present invention, even if the optical fiber bundle further wound with the bunching yarn is exposed to a high temperature, the yarn does not thermally shrink, and thus the tightening does not occur.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Suehiro Miyamoto 1440, Musaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Plant

Claims (3)

[Claims] 1. An optical fiber bunching yarn comprising a yarn obtained by twisting a plurality of long fiber filaments 100 times or less per m. 2. The yarn for optical fiber bunching according to claim 1, wherein a surface treatment agent such as an antistatic agent and a sizing agent is applied to the long fiber filament. 3. The optical fiber bunching yarn according to claim 1, wherein a heat treatment at 60 to 100 ° C. is performed.