JPS60161357A - Pressure type coating device for optical fiber - Google Patents

Abstract

PURPOSE:To prevent the short-pass phenomena of a coated resin, and to form a uniform and thick coating on the outer circumference of an optical fiber at a high linear speed by forming an eccentric passage part with a nipple and a holder which are eccentric to each other at a part of a circulating passage of the resin. CONSTITUTION:An optical fiber (f) is pulled from the inlet port 2' of a nipple 2 through the outlet port 3' of a die 3. A liquid resin is supplied under pressure from a resin supply port 15, and uniformly charged from a resin pool 14 into a concentric and conical part 13b of an almost uniform clearance (g) along the circumferential direction through a cylindrical part 13a of a resin circulating passage 13. In this case, the base end 10b of the nipple 2 is made eccentric to the leading end 11b of a holder 4 to the extent of L to narrow the G' of the clearance G on the supply port side 15 and to broaden the G'' on the opposite side in the axial direction. Accordingly, the resin from the outlet port 3' of the die 3 is coated on the outer circumference of the optical fiber (f) in uniform thickness. The optical fiber is subsequently introduced into an ultraviolet curing furnace or a heating type curing furnace wherein the coated resin is cured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressurized coating device for forming a primary coating on the outer periphery of an optical fiber.

As is well known, quartz-based, multicomponent-based, or other glass optical fibers are coated with a resin such as Comb or Plascenc immediately after spinning.

For coating in this case, it is considered advantageous to use a pressure-type coating device that can increase the speed of light and fiber. By concentrically combining the nipple and the die at the tip, a ring-shaped resin flow path having a uniform cross section of -rlJ is formed between the inner and outer circumferences of the nipple, the holder, and the die, and The surface has a resin supply seam communicating with the resin flow path n;
It is formed as J.

To coat an optical fiber using this, the liquid resin is supplied under pressure from the resin supply port to the resin flow path, and the optical fiber is drawn from the nipple to the die, and the outer periphery is coated with the liquid resin. The primary coating is formed and then the secondary coating is cured by any suitable means.

However, in the case of the above-mentioned coating means, although it is a pressurizing type, the resin pressure cannot be increased indefinitely considering the characteristics of the optical fiber, and therefore the resin supply pressure is 10 Kq lower than that with plastic extrusion molding means etc. /cnI or less, and as a result, the pressure loss of the resin flowing in the resin flow path is large (as a result, the coating resin is
There was a problem that a so-called iodine path phenomenon occurs in which a large amount of iodine flows through the "supply" side of the side flow passage, and a uniform coating 19 cannot be obtained on the outer periphery of the optical fiber, resulting in uneven thickness.

The present invention has been made to solve the above problems, and its configuration will be explained below with reference to illustrated embodiments.6 In FIG. In this coating device 1, an inner nipple 2 and a die 3 at the tip are combined into a phase U via an outer porter 4.

The nipple 2 is fitted and fixed to the holder 4 by a nipple presser 6 screwed onto the upper part of the holder 4, and both 2 and 4 exhibit an eccentric state as described below, but this eccentric state can be optimally adjusted. In order to set the position, the nipple 2 housed in the holder 4 can be rotated around its vertical axis, and the positioning hole 6 on the nipple 2 side can be adjusted to determine whether the adjusted state is
A and a positioning hole 6b on the side of the holder 4, and a stop pin 5c inserted between the positioning hole 6b on the side of the holder 4 allows it to be fixed.

In this case, it is preferable that one or both of the positioning holes 5a and 5b be provided in plural numbers at intervals in the circumferential direction on the outer periphery of the body of the nipple 2 and on the outer periphery of two sides of the boulder 4, respectively. In addition, the positioning hole 6a, the positioning hole 6
When one of b is singular and the other is plural, a stop pin 6c may be fixed to the singular hole 5a or hole 51).

The one-brim die 3 is fitted into a fitting hole 7 drilled at the tip of the bolter 4, and is fixed with a tie holder 8 screwed to the lower part of the boulder 4. 3 and the boulder 4 are rearranged concentrically, and 9 in the figure indicates an opening for the optical fiber f vertically installed in the die holder 8.

The distal end outer peripheral surface 10 of the nipple 2, the distal end of the halter 4 (till inner circumference 1hii1 and the inner peripheral surface 1 of the die 3)
A resin flow path 13 is formed between the resin flow path 130 and the resin flow path 130, and a resin retainer 14 is connected to the base end of the resin flow path 130. One or more resin supply ports 16 are opened to communicate with the resin reservoir 14.

This resin flow path 13 consists of a circular portion 13a and a conical portion 131 with a V-shaped cross section following the circular portion 13a.
3b is such that the gap g; Shaped, nipple 2 tip person 1
The hole 2' and the exit hole 3' of the die 3 tip "1." are also concentric with each other.

- As clearly shown in FIG. 2, the cylindrical portion 13a of the resin flow passage 130 is an eccentric passage section with the supply supply [1 side G' being narrow and the opposite side G'' being wide. Therefore, the nipple tip side outer circumference 11I
proximal end 10b of j10 or halter tip); j6 fi11
The inner peripheral surface 110 is formed eccentrically with respect to the base end 11b, and the base end 10b of the outer peripheral surface 1Q of the tip of the nipple is
The connecting portion between the tip portion 10a and the tip portion 10a is inclined from the supply port 15 side to the opposite end side.

Therefore, in order to coat the optical fiber f using this device, the optical fiber /. At the same time as drawing the resin through the outlet hole 3', it is preferable to supply the liquid resin to the resin flow passage 13 under pressure from the resin supply 1'' 15, and in this case, the resin flow passage 130 cylindrical portion 13a should be connected to the supply port side as described above. Since the eccentric passage is narrowed, the resin does not flow too much through the supply 11!11 of the flow passage 13, and is uniformly distributed over the circumferential direction to the conical part 131). exit hole 3
', the outer periphery of the optical fiber f is coated with a uniform thickness, and the coated original fiber is then inserted into an ultraviolet curing furnace or a heated curing furnace, where the coating resin is cured.

Note that the degree of eccentricity applied to the above-mentioned core passage can be adjusted by relative rotation between the nipple 2 and the halter 4. ), II-Mebin 5c can not only serve as a means for fixing the adjustment state, but also these holes 6a, 61
) is provided as a reference for adjusting the hole 6a or hole 5b.

In addition, when a plurality of resin supply ports 16 are provided at intervals in the circumferential direction around the Porcu 40, liquid resin can be supplied into the resin C passage 13 from an arbitrary number of resin supply ports 16. At this time, each supply port 15 is equipped with a needle valve type throttle valve mechanism that can be freely opened and closed. can also be done.

Of course, the eccentricity mentioned above, the number and position of the resin supply ports to be used are set appropriately according to the viscosity of the resin, the coating thickness, the volume of the resin flow path, etc. By taking these adjustment measures, various coatings can be used. The optimal conditions according to the situation are determined,
Uniform coverage can be achieved over a wide area.

As explained above, in the present invention, a die is attached to the tip of a cylindrical holder, a nipple is installed inside the holder, and a resin flow path is formed between the inner and outer peripheries of the nipple, the holder, and the die. In the pressurized optical fiber coating device, the holder has a resin supply port that communicates with the resin flow path, and a part of the resin flow path has an eccentric path formed by mutual eccentricity between the nipple and the holter. Since the optical fiber is formed with a section, it is possible to prevent the conventional coating resin from passing, and the outer periphery of the optical fiber can be coated with a uniform thickness, and the coating can be carried out at a high linear speed.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view showing an embodiment of a pressure-type coating device according to the present invention, and FIG. 2 is a sectional view taken along the line II--II in FIG. 1. 1...Pressure type coating device convex 2...1 Nipple 3...-Dice 4...φ...Holter 13...(21 Fat flow path 13a... The cylindrical part of the resin b1 passage (flii
t cardiac passage) 15... (collinear patent originator 1 patent attorney Ito rolIJ. Fig. f Fig. 2

Claims (1)

[Claims] A die car is attached to the tip of a cylindrical halter, and a nipple is installed inside the die.A resin flow path is formed between the nipple, the porter, and the inner and outer circumferences of the die. In the pressurized coating device 171 for the optical fiber, which has a resin supply port that communicates with the channel, an eccentric channel section is formed in a part of the resin flow channel due to phase Ij-eccentricity between the nipple and the holder. A pressurized coating device for optical fibers with a 1″F signature.