JPS6123104A - High density storage type optical fiber cable - Google Patents

Abstract

PURPOSE:To improve the productivity, safety, and operability by coating an optical fiber core cylindrically with an adhesive plastic tape, and heat-welding the external adhesive surface of the adhesive plastic tape with synthetic resin for one-body coating. CONSTITUTION:The tape type optical fiber core 1 is covered cylindrically with the adhesive plastic tape 4. The adhesive plastic tape 4 is formed by laminating an adhesive film 4b on a plastic tape 4a in one body by heat welding. Further, end parts A of the plastic tape 4 are superposed lengthwise one over another and the low-strength part which is formed at the conventional butting part B is eliminated. Then the adhesive plastic tape 4 is formed cylindrically with the adhesive film 4b outside and the surface of the adhesive film 4b is coated with the synthetic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to optical fiber cables for subscribers that are branched off from trunk cables.

<Prior Art> Currently, the development trend of optical communication cables is shifting from trunk cables to optical communication cables for subscribers. One of the most important development items for optical communication cables for subscribers is high-density packed optical fiber cables in terms of cable costs. For this type of cable, a tape-shaped optical fiber in which a plurality of optical fibers are integrated into a tape-like structure is considered to be promising. This method was developed as a method for accommodating such tape-shaped optical fibers in a fixed number of units without impairing their optical conductivity, and gathering them together into a cable. Coating,
There is a so-called LAP pipe, which is formed by molding a vibrator 2 and coating it with polyethylene resin 3 (see Figure 1).
If the pipe diameter is less than 10 mm, the forming resistance will increase due to the repulsive force and the forming performance will deteriorate, resulting in lower productivity.In addition, since the tape is made of metal, there are safety concerns due to lightning strikes and induced currents. Furthermore, since the weight of aluminum is large compared to the weight of the optical fiber, there is the problem that the weight of the entire cable increases and the workability deteriorates.

<Object of the Invention> The entire object of the present invention is to provide a high-density packed optical fiber cable with high productivity, safety and workability, which eliminates the above-mentioned drawbacks of conventional LAP pipes.

<Configuration of the Invention> The configuration of the present invention that achieves the above object is such that an optical fiber core is coated in a cylindrical shape with an adhesive plastic tape, and a synthetic resin is further bonded to the outer adhesive surface of the adhesive plastic tape by heat fusion. It is characterized by being integrally coated,
A further preferred embodiment is characterized in that the ends of the adhesive plastic tape overlap in the longitudinal direction.

<Example> Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

　　　′ FIG. 3 shows a sectional view of the optical fiber cable of the present invention.

As shown in the figure, a tape-shaped optical fiber core 1 is wrapped in a cylindrical shape by an adhesive plastic tape 4.

As shown in FIG. 2, the adhesive plastic tape 4 is formed by integrally laminating an adhesive film 4b onto a plastic tape 4a by thermal fusion. It is preferable to use a polyester tape as an example of the plastic tape 4a, and to use an adhesive polyolefin resin such as ethylene vinyl acrylate as an example of the adhesive film.

Further, as an example of manufacturing the adhesive plastic tape 4, a plastic tape 4a having a thickness of about 75 .mu.m, an adhesive film 4b having a thickness of about 50 .mu.m, and a tape width of about 13 mm can be manufactured. Furthermore, the adhesive plastic tape 4 according to the present invention is molded with its ends A overlapping each other along the longitudinal direction. In the conventional LAP pipe, the end part B is formed by butting, and the above-mentioned overlapping part does not occur, whereas in the present invention, such an overlapping part A=i
This prevents the weakening of the strength seen in the conventional abutting part B from occurring.

The width of the overlapping part A is 1096 in the entire tape.
It is better to make it more than that.

Next, the adhesive plastic tape 4 is formed into a cylindrical shape with the adhesive film 4b2 outside, and the surface of the adhesive film 4b is coated with the synthetic resin 3. The synthetic resin 3
For example, polyethylene is used, and the polyethylene is extruded and coated on the adhesive film 4b, and the adhesive film 4b and the polyethylene are thermally fused and integrated by the heat of the plastic 3 during extrusion.

Through the above manufacturing process, a high-density optical fiber communication cable having a diameter of about 44 φ, for example, can be obtained.

<Effects of the Invention> The high-density storage type optical fiber cable according to the present invention has the following advantages.

(1) Since adhesive plastic tape is used, the molding resistance is low, cylindrical molding is easy, and there is no tape cutting even if the manufacturing speed is significantly increased, making it about 3 times more efficient than conventional LAP pipes. You can achieve productivity improvement.

(2) Since plastic tape is used instead of conventional metal tape, the weight of conventional LAP tape is reduced, and the tension members for cable laying and erection can be made smaller, significantly improving work efficiency. do.

(3) Unlike conventional tapes that use metal tapes, the present invention uses plastic tapes, which can prevent adverse effects from lightning strikes, induced currents, and the like.

(4) Unlike conventional LAP pipes, the tape ends are overlapped and molded, so a cable with excellent product strength can be obtained without any weak spots.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal side view showing an example of a conventional LAP pipe, Fig. 2 is a side view of an adhesive plastic tape according to the present invention, and Fig. 3 is a side view showing an example of a high-density storage type optical fiber cable of the present invention. FIG. In the figure, l-tape-shaped optical fiber core, 2-aluminum tape, 3-synthetic resin, 4-adhesive plastic tape, 4a
- plastic tape, 4b - adhesive film.

Claims (2)

[Claims] (1) High-density optical fiber coated with an adhesive plastic tape in a cylindrical shape, and the outer adhesive surface of the adhesive plastic tape is integrally coated with a synthetic resin by thermal fusion. Storage type fiber optic cable. (2) Claim 1, characterized in that the ends of the adhesive plastic tape overlap in the longitudinal direction.
High-density storage type optical fiber cable as described in Section 1.