JPS59190242A - Production of optical fiber coated with plastic - Google Patents

Abstract

PURPOSE:To produce optical fibers, coated with a plastic, and having transmission characteristics, temperature characteristics, connection workability and water pressure resistance characteristics, by providing a specific interlayer having zero hardness and no fluidity between an element wire of the optical fibers and a reinforcing resin layer for covering the outer periphery thereof. CONSTITUTION:An element wire (A) of an optical fiber is rewound from a feeder 1 and fed to a coater 2. A liquid silicone based resin composition (B) having thixotropy of becoming a liquid on application of force in the coater 2 thereto and changing into a solid on removing the force is applied to the outer periphery of the element wire (A) of the optical fiber by giving the fluidity to the composition (B) under pressurizing with a plunger. The resultant coated element wire (A) is then put into a curing furnace 7 and cured by heat energy or light energy to form a gelatinous material interlayer (C') having zero hardness and such a thickness (t) as to give about t/d>=0.6 [d is the outside diameter of the optical fiber (A)]. A reinforcing layer (D') of a thermoplastic resin is formed on the outside thereof by an extrusion coater 8, and the optical fiber (A) is passed through a cooling bath 9 and then wound onto a winder 10.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a plastic coated optical fiber.

One of the plastic-coated optical fibers called optical fibers and B-lines has a loose structure.The coated optical fiber with this structure has a complementary Akakusu-Tsubaki optical fiber wire and its outer periphery. A liquid intermediate layer with high viscosity is interposed between the reinforcing resin layer and exhibits various excellent characteristics and effects depending on this intermediate layer.

In other words, even if the linear expansion coefficients of the optical fiber (glass) and the sleeve-reinforced resin layer (plastic pipe) are different, the liquid intermediate layer allows smooth movement between the optical fiber and the plastic pipe. When handling a pipe, the pipe contracts in the longitudinal direction, and the original fiber is delivered in a gentle meandering state within the pipe.When the pipe expands and contracts due to temperature changes, the stretching force is applied to the optical fiber. In addition, no distortion occurs in the -C optical fiber, and the problem of increased transmission loss hardly occurs.

However, in the coated optical fiber described above, since the intermediate layer is liquid and has fluidity, the following problems are also observed.

When connecting optical fiber pipes 11 to each other, the liquid intermediate layer flows out from the ends of the pipes, and furthermore, the optical fibers within the pipes are unstable (because of this,
One side is connected and separated, which is time-consuming.

In addition, in cases where the water ratio is quite high, such as in submarine installations, or in cases where high-temperature cables are used, such as in overhead cables (temperatures of up to 200 degrees Celsius in summer), it is necessary to remove liquid intermediate water from connection points or other pipes. Δ may also leak, and countermeasures must be taken to prevent this, resulting in structural failure.

−10,000, when considering the above-mentioned coated optical fiber from a manufacturing perspective,
Since the intermediate layer is in a liquid state, it is difficult to interpose it between the original fiber wire and the pipe (one finger of reinforcing resin), and the layer is thinner than the optical fiber wire before being coated with the reinforcing resin layer f. Even if a liquid material is produced for the outer periphery (this middle layer),
1. When molding a reinforcing resin layer into a pipe, a highly difficult method such as filling the pipe with the liquid material at the same time is necessary. Must be.

However, some of the above-mentioned problems can be solved if the intermediate layer is formed from a gel-like substance with shapeability instead of a liquid, but it is difficult to form a gel-like substance in terms of transmission characteristics and temperature characteristics. The degree of formability that is given to the substance is interesting, and the gel-like material here (even if it is gelled, the fluidity is very high at the point where it becomes a gel, so there are manufacturing problems like the liquid form mentioned above). Tomo.

Misfire 1! +4 Problems mentioned in Vi-J 2 (In view of this, when manufacturing this kind of plastic-coated optical fiber,
By forming an intermediate layer with a special layer θ, various W
This product enables a plasticized optical fiber with high properties to be manufactured easily and efficiently.

The inventive method will be explained below with reference to the illustrated embodiment.
d. The yarn is unwound from the drum-shaped rotary feeder 1 and is rolled in a certain direction 91.

This optical fiber wire A is a silica-based optical fiber (outer diameter 125
71m) on the outer periphery of the primary coat - i lc ri buffer coat or both coats) / t Jf -
i Zl silicone resin, silicone type, etc.=1
-1・IM (outer diameter 03)'run) is provided.

211 G and re-plug: The 4 combined optical fiber strands A are applied to (-J Shimecoating IJ machine 2.

As shown in Fig. 2, this applicator 2 has a pressure section 6 equipped with a plunger 3 and a cylinder 4, and a cylinder 4 of the pressure section 5.
It consists of one molded part 6 connected to each other, and the cylinder 4 (burnt liquid wood) is housed with a credit union J-shaped part B.

Liquid resin composition Bl-j: Thigisotropic (thi) which becomes liquid when force is applied and becomes solid when force is removed.
xotropy - has thixotropy, pseudo(idacity),
Specifically, the resin composition B is silicone-based (
Toray silicone gcys with initial dryness 1i3000cPs
2-264) is used.

Since the resin composition B is pressurized by the plunger 3 in the cylinder 4 of the applicator 2, it has fluidity. It will be supplied to Japan.

Therefore, once the optical fiber strand A described above passes through the forming section 6 of the coating machine 1, the outer circumference of the optical fiber strand A has an outer diameter of 0.7 rr.
A resin composition layer (intermediate layer) of about a thickness is formed, and the original fiber strand A becomes an uncured intermediate coated optical fiber C.

Thereafter, the resin composition (intermediate layer) of the meson-covered optical fiber C exhibits a state with no fluidity, and in this state, the intermediate covered optical fiber C follows the curing furnace 7 shown in FIG. Here, the above-mentioned tree shell composition (intermediate layer) - hardened stingray,
Gel-like material 5″↓1 (two-year-old) after receiving rugi.

At this time, thermal energy or optical energy is used for curing, and the resin composition, that is, the intermediate layer is a gel-like substance in a semi-crosslinked state.

The hardness of the intermediate layer made of a gel-like substance is determined by the JIS standard 4 (K
0 at 6 3 0 1), 4- to AST
D1321 comes out at 80, -.

Hereinafter, the intermediate coated optical fiber C is passed through an extrusion handling machine 8 (extrusion handling machine 8), and the outer periphery of the intermediate layer (heated plastic resin (nylon),
11 FI layers of reinforced wood (polyethylene, etc.) (outer diameter 0.
9 mm) is formed into a predetermined colored optical fiber (■), and the hindlimb strong optical fiber D J4 cooling 41jll is formed.
9, it is water-cooled, and then wound onto a drum-type winder 10.

FIG. 3 (I:ll) is a cross-sectional view of the coated optical fiber (optical fiber lb line) manufactured as described above, and the same figure shows 2
In the figure, A is the optical fiber wood wire described above, C' is an intermediate layer made of a gel-like substance, and D'+ is a reinforcing resin layer made of a thermoplastic resin.

Note that in the above ζ, if the outer diameter of the optical fiber A is d, and the thickness JQ of the gel-like substance constituting the intermediate j*C' is L, then t/a≦0.6 f 1! It is best to set the thickness of the intermediate layer C' so as to add a, and in such a case,
When made into a cable, the elongation relaxation property, that is, the cable elongation (stiffness) of the optical fiber can be reduced to 1 or less.

In addition, when forming the intermediate layer C' where t/d≧06 is added to H(, + In order to reduce the thickness, it is best to form a gel-like substance in one coating (1), and even in such a case, a uniform intermediate layer C' can be obtained over a length of about 1,000 m.

As described above, the present invention (a) is a manufacturing capability of a plastic-coated optical fiber in which an intermediate layer is interposed between an optical fiber strand and a reinforcing resin layer provided on its outer periphery.
Now, add 1 piece of the 2fM composition to the 1 piece of the 2fM composition that forms the middle layer. After applying the flowing resin composition to the outer periphery of the optical fiber 2+,
To the resin composition, f1 modified stingray, lugi, riete J I
s) Since the hardness according to A rating (16301) is O, it is characterized by the creation of a non-flowable tar-like material, so the intermediate layer made of the gel-like material is a non-', which has a hardness of 0. +i
c! , 1lIJ case, the surrender characteristic, Hatato special) cow, J〆continuation 111i's i'l',>'i! L
%1 water control pressure! 1h da L, etc. 111 C and to 4
・Moreover, coating on the optical fiber wire: +;, 1-
Kiju 11') 7 +1l-f acid! 'j flow, :rp-
7, If it is applied, the coating is line 7. become empty,! 4'5 Deformation of the intermediate layer 7 due to fluidity, further 1 + - 1 Reinforcement and fattening on the outer periphery of this 1) Intermediate layer q when forming 1
・There is no 11/11 or 19/l- of I'lII output due to 1 lost item. (There is no neck in the line, so you can control the line speed.

[Brief explanation of the drawing]

Figure 1-1: An explanatory diagram schematically showing one major example of the invented method, Figure 2 (d same as This is a cross-sectional view of a coated optical fiber manufactured by the method.・Intermediate J-thread D...Enriched optical fiber D'...Reinforced resin layer 2...Coating machine 5...Coating A9-I Pressure part 6...・Complete the molding section of the coating machine ・・Patent attorney Makoto Ito, patent attorney for curing furnace

Claims (4)

[Claims] (1) In a method for manufacturing a plastic-coated optical fiber in which an intermediate layer is interposed between an optical fiber strand and a reinforcing resin layer provided on the outer periphery thereof, in the step of forming the intermediate layer, After applying the fluid resin composition to the outer periphery of the optical fiber, the resin composition of this section (to change the cooling energy) is applied. JIS standard (K63
01. ) (1. A method for manufacturing a plastic-coated optical fiber that produces a gel-like substance with no fluidity and a hardness of O. (2) A method for manufacturing a plastic flannel-covered optical fiber according to claim 1, in which a liquid resin composition (1η) that has good fluidity is pressurized. (3) The plastic-coated optical fiber according to claim 1, which produces a gel-like material that satisfies t/d≧06, where the outer diameter of the optical fiber is d1 and the wall thickness of the gel-like material is t and 7C. manufacturing method. (4) A method for manufacturing a plastic-coated optical fiber according to Patent N'R Claims Item 1, in which a fluid resin composition is coated once on the outer periphery of the optical fiber.