JPH01201050A - Manufacturing method of optical transmission line - Google Patents

Abstract

PURPOSE:To improve wettability of a fiber surface in normal coating and contrive an increase in drawing speed and improvement in productivity, by precoating a glass fiber for optical transmission just after melt spinning with a liquid resin composition, passing the glass fiber through a liquid bath, normally coating the glass fiber with the same liquid resin composition and baking the resin composition. CONSTITUTION:A glass fiber 11 for optical transmission obtained by melt spinning from a preform 10 is precoated with a liquid resin composition with, e.g. a felt pad 16, just after the melt spinning to improve wettability of the fiber surface. The pretreated glass fiber 11 is subsequently led to a liquid bath 12 containing the same liquid resin composition 13, normally coated therewith, then taken out of a die at the outlet and fed to an electric furnace 14 to heat and bake the coated liquid resin composition and subsequently wound onto a reel 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to a method of manufacturing an optical transmission line using glass fiber.

[Prior art and its problems] Conventionally, a coating film of a resin composition has been formed by applying and baking a liquid resin composition onto a glass fiber for optical transmission.

Various coating and baking methods have been proposed in this case, but the most common one is the method shown in FIG.

In this method, immediately after the optical transmission glass fiber 21 is melt-spun from a base material 20, a liquid resin composition 23 is applied through a liquid tank 22 before being wound onto a reel, and then heated and baked in an electric furnace 24. , and then wound onto a reel 25.

In such a method, applying and baking the resin composition is extremely simple, but if the drawing speed during melt spinning is increased, the resin composition 33 in the liquid bath 32 will be coated and baked as shown in FIG. An "ant hell" phenomenon occurs, and when the drawing speed is further increased, this "ant hell" disappears, resulting in a phenomenon in which the liquid resin composition 33 is not applied at all to the surface of the optical transmission glass fiber 31. .

However, in order to improve the productivity of optical transmission lines, it is essential to increase the drawing speed, so some kind of improvement measure has been required.

[Objective and Summary of the Invention] In view of the above circumstances, the present invention aims to provide a practical method for manufacturing an optical transmission line that solves the problems of the prior art. The liquid resin composition is preliminarily applied before the drawing process to improve wetting of the glass fiber surface, and as a result, even when the drawing speed is increased, a coating film of the resin composition can be reliably formed.

[Example] The present invention will be specifically explained with reference to FIG. 1 showing an example.

In FIG. 1, reference numeral 11 indicates a glass fiber for optical transmission that is melt-spun from a base material 10.

This optical transmission glass fiber 11 is preliminarily coated with a liquid resin composition using a felt pad 16 immediately after melt spinning.
Thereafter, the liquid resin composition is applied by passing it through the liquid tank 12.

At this time, the felt pads 16 are sufficiently impregnated with a liquid resin composition, and the felts are slightly spaced apart so that no stress is applied to the optical transmission glass fibers 11.

The shape of the liquid tank 12 is not particularly limited, but it is practical to use a pot with a die (for example, diameter 0.3a+m) at the outlet. It serves not only to apply the composition but also to remove excess liquid resin composition.

After the liquid resin composition is applied in this manner, it is heated and baked in the electric furnace 14 to form a coating film of the resin composition on the surface of the optical transmission glass fiber.

The reason why pre-coating is provided is because the wettability during main coating is better when the liquid resin composition that is pre-applied using a felt pad and the liquid resin composition that is actually applied by passing through a liquid tank are of the same type. increases.

Further, if such a coating film is formed, it can be handled freely by winding it up on a reel or the like, but it goes without saying that a plastic sheath for protection may be extruded and coated on the outer periphery.

[Effects of the Invention] According to the manufacturing method of the present invention, the liquid resin composition is pre-coated, so the surface of the optical transmission glass fiber is well wetted during the main coating, and the drawing speed is increased. A coating film of the resin composition can be reliably formed even when the resin composition is used.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a conventional method of manufacturing an optical transmission line, and FIG. 3 is a partial explanation of a conventional method of manufacturing an optical transmission line. It is a diagram. 10: Base material, 11: Glass fiber for optical transmission, 12: Liquid tank, 13: Liquid resin composition, 14: Electric furnace, 15: Reel. 1st item

Claims (1)

[Claims] (1) Immediately after melt-spinning glass fiber for optical transmission, a liquid resin composition is pre-coated, and then the liquid resin composition is applied by passing it through a liquid bath, and the liquid resin composition is further coated. 1. A method for manufacturing an optical transmission line, comprising forming a coating film of a resin composition on the surface of an optical transmission glass fiber by baking.