JPS60122754A - Manufacture of optical fiber element wire - Google Patents

Abstract

PURPOSE:To manufacture an optical fiber with a covering material uniformly deposited along the whole circumference by arranging plural nozzles at intervals of an equal angle around the circumference of the optical fiber which is drawn continuously. CONSTITUTION:A preform 1 for an optical fiber is softened and melted in heating furnace 2, and drawn continuously to form an optical fiber 3. Then plural spray nozzles 4a, 4b, and 4c are arranged at intervals of a practically equal angle around the optical fiber 3, and a covering material 5 is blown against said optical fiber 3 from the spray nozzles 4a, 4b, and 4c. Then the optical fiber 3 with the deposited material is passed through a curing furnace 6, and the deposited covering material is cured to obtain stably an optical fiber element wire 7 having a covered layer having an uniform thickness. Said plural spray nozzles 4a, 4b, and 4c can be slid in the traveling direction of the optical fiber 3, or 2 sets of plural spray nozzles may be arranged in the traveling direction of the optical fiber 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an improvement in a method for manufacturing an optical fiber element S by applying a brimary coating to an optical fiber formed by drawing.

[Prior art]

A common method for coating a coating material in the optical fiber drawing process is the so-called depping method, in which a liquid coating material is coated while passing the optical fiber through a die. Covering materials such as silicone have been coated with this method. However, this method has a problem in that it is not possible to form a thin coating with a thickness of several μm. For this reason, the conventional method for thin coating has been to continuously impregnate the felt with a low-viscosity cladding material and coat the optical fiber by sandwiching the felt. However, this method also has drawbacks such as (1) the coating is not stable, and (2) the strength is deteriorated because it touches the optical fiber 11E7.

Therefore, recently, a method of spraying a coating material onto an optical fiber has been studied. In this method, an optical fiber preform is softened and melted in a heating furnace and continuously taken off to form the original fiber, and then a mist of the optical fiber is sprayed onto the target material using a spray nozzle, and then guided to a curing furnace. The method is to harden the adhered substrate. However, this spray method has a problem in that the coating thickness becomes non-uniform because the coating material mist adheres to the optical fiber only from a biased direction.

[Purpose of the invention]

In view of the drawbacks of the prior art as described above, an object of the present invention is to
It is an object of the present invention to provide a method for manufacturing an optical fiber wire that can obtain a uniform coating thickness over the entire circumference of an optical fiber by a spray method.

[Structure of the invention]

In order to achieve the above object, the present invention involves forming an optical fiber by softening and melting an optical fiber preform in a heating furnace and continuously pulling it out, and then coating a substrate thereon to form an optical fiber. A method for manufacturing a wire, characterized in that a plurality of spray nozzles are arranged around the optical fiber at substantially equal angular intervals, and the target material is sprayed onto the optical fiber from these spray nozzles. .

〔Example〕

1 and 2 show one embodiment of the present invention.

In this method, an optical fiber preform 1'Jk is heated in a heating furnace 2 to soften and melt it, and is continuously pulled downward to form an optical fiber 3. Three spray nozzles 4a arranged in
After spraying the target material mist 5 onto the optical fiber 3 from 4b and 4c, the attached target material is cured through a curing furnace 6 to obtain an optical fiber wire 7. In this case, the building material mist 5 is applied almost uniformly to the optical fiber 3 from the surrounding area, so the thickness of the coating layer can be made uniform, and the position of the optical fiber is stabilized, so that the outer diameter There is less loading (and the coating is also stable.

FIG. 3 shows another embodiment of the invention. This method uses three spray nozzles 4a arranged at 120 degree intervals in the circumferential direction.
, 4b, 4c v are arranged with their positions shifted in the running direction of the optical fiber 3, and the coating material is sprayed under pressure to perform coating. In this way, interference between the spray nozzles can be prevented.

FIG. 4 shows yet another embodiment of the invention. In this method, optical fibers are arranged at 120 degree intervals in the circumferential direction and
Two sets of three spray nozzles 4a, 4b, and 4c arranged at 0 mV offset in the running direction of the optical fiber 30 are provided to perform coating. This method is effective for increasing the coating thickness.

In each of the above embodiments, three spray nozzles are arranged at equal angular intervals around the optical fiber, but the number of spray nozzles arranged at equal angular intervals around the optical fiber may be two or more. You can use as many as you want. In the embodiment shown in FIG. 4, it is also possible to use three or more sets of spray nozzles.

〔Effect of the invention〕

As explained above, according to the present invention, the material to be coated is sprayed onto the optical fiber using a plurality of spray nozzles arranged at substantially equal angular intervals around the original fiber. Since the thickness of the coating layer around the optical fiber becomes uniform and the position of the optical fiber is stabilized, there is little variation in the outer diameter (there is also an advantage that the coating is also stable).

[Brief explanation of the drawing]

Fig. 1 is a top view showing Embodiment 1 of the manufacturing method of the present invention, Fig. 2 is a cross-sectional view taken along the line nn of Fig. 1, and Fig. 3 shows another embodiment of the present invention, showing the main parts. FIG. 4 is a perspective view showing main parts of still another embodiment of the present invention. 1... Optical fiber preform, 2...
...Heating furnace, 3...Optical fiber, 4a*4b+
4c...Spray nozzle, 5...Material mist, 6...Curing furnace, T...Optical fiber 〇,.../- Applicant's representative People Patent attorney Hiroshi Wakabayashi! ,”,: ”,:
"-';・(--I Figure 1 Figure 2; Figure 3 Figure 4

Claims (1)

[Scope of Claims] (1) After forming an optical fiber by softening and melting an optical fiber preform in a heating furnace and continuously taking it off, a coating material is coated thereon to form an optical fiber. In the method for manufacturing lkM, a plurality of spray nozzles are arranged around the optical fiber at substantially equal angles,
A method for producing a Hikari 7-Iver wire, which comprises spraying the above-mentioned coating material onto an optical fiber from these spray nozzles. (2. The manufacturing method according to claim 1,
The invention is characterized in that the plurality of spray nozzles are arranged with their positions shifted in the running direction of the optical fiber. (3) The manufacturing method according to claim 1 or 2, wherein a plurality of sets of spray nozzles arranged at substantially equal angular intervals in the circumferential direction are arranged in a direction in which the optical fiber runs. It is characterized by having two or more sets arranged in the.