JPS6163810A - Production of tape-like fiber core - Google Patents

Abstract

PURPOSE:To thin a tape core by coating an external surface of adjacently arrayed optical fibers with ultraviolet ray hardening resin to form a flat tape- like shape and irradiating the uniform quantity of ultraviolet rays simultaneously to both the sides to harden the resin. CONSTITUTION:Plural optical fibers or optical fiber strands 3 covered with protection coats are adjacently arrayed and their outer periphery is coated with the ultraviolet ray hardening resin to form the flate tape-like shape and the uniform quantity of ultraviolet rays are simultaneously irradiated to both the sides to harden the resin. Since the resin is applied to the cores uniformly by containing felt e.g. in the resin, the optical fibers can be prevented from the generation of a warp and transmission loss. Since ultraviolet rays are uniformly irradiated to the resin-coated tape-like unit from the right and left directions and upper and lower directions of the flat surface at the initial stage of hardening. Consequently, the tape-like optical fiber constituted of a thin layer can be obtained.

Description

[Detailed description of the invention] Technical field of invention The present invention relates to a method for manufacturing a tape-shaped optical fiber core.

In particular, the present invention relates to a method of manufacturing an optical fiber core using an ultraviolet curable resin as a protective coating for a multi-core optical fiber.

Technical background: Arrange multiple optical fibers in a row to form a protective coating. I
It is possible to easily construct a high-density multi-core cable that can be housed in multiple fibers by taking advantage of the anchor characteristics of optical fibers. Based on the structure of this high-density multi-core cable, it has been developed for the purpose of application to small-diameter multi-core cables, mainly for optical subscriber line systems. For example, in step 5 shown in Factor 1, a plurality of coated optical fibers 3 are arranged adjacently, and a protective coating 24e of thermoplastic resin is placed on the outside and side. Core wire 1,
In the process 5 shown in Fig. 1 b, there is a tape 5 with adhesive attached from both sides of the flat surface t of the optical fibers 3 arranged adjacent to each other. 4 etc. are known. [For example, Yose et al.: 1939
7 Confucian Communication Comprehensive National Conference 1801 (1982),
G, Broekwmy @tat: proc
@@ding of bth EC0C (19
80) ] The extrusion type or tape lamination type tape core wires 1 or 14 are laminated, for example, in a pipe-shaped member 6 as shown in the first factor C, to constitute a multi-core cable unit. .

Prior Art and Problems Conventional extrusion type or tape laminated type core wires do not require protective liquid y.
The material increases the diameter of the tape core, i.e., thin IJ.
1@, and it is desired to further reduce the diameter of the tape core wire for multi-core cable units such as optical subscriber line systems.

OBJECTS OF THE INVENTION An object of the present invention is to provide a method for manufacturing a tape-shaped optical fiber coated wire in which the diameter of the tape coated wire is reduced.

Structure of the Invention The present invention provides a tape-shaped body by applying an ultraviolet curable resin to the outer surface of an optical fiber or a plurality of optical fiber wires each having a protective coating applied to the optical fiber and arranged adjacent to each other, and flattening the tape-shaped body. Is it possible to produce a tape-shaped optical fiber by curing the UV-curable resin with a uniform amount of light on both sides at the same time? This is a characteristic feature. This will be explained below using figures.

Embodiment of the Invention FIG. 2 is a diagram showing a second outline of the manufacturing method of the invention. A glass fiber coated with a silicone resin or an ultraviolet curing resin is fed out from an optical fiber supply device 10,
Align with concentrated lines 8111. The aligned wire groups 15 enter the ultraviolet curing resin coating device 12, and after the ultraviolet curing resin is applied almost uniformly to the outer part of the wire group 15, they are sent to the ultraviolet curing resin curing device 16, where the resin is cured. be done. In addition, when coating multiple shoes, use ultraviolet curing resin coating device 1.
2' and curing device 13', the coating and curing steps are repeated. The tape core wire 16, which has become tape-like due to hardening of the resin, is wound around the winding device 14. Also, UV curing resin directly on glass fiber? It may be applied and cured.

FIGS. 6a and 6b show cross-sections of the ribbon cable produced according to the present invention. FIG. 3 1 shows an example in which the ultraviolet curing resin limb covering is a single-layer coating 7 and FIG. 3 shows an example in which a two-layer coating 8 and 9 is used. Is it possible to improve the stability of transmission characteristics and mechanical properties by changing the combination of UV curing resins as necessary? It can be measured.

When manufacturing this type of tape, the most important issue is the shape of the tape core. If the UV-curable resin cannot be applied uniformly onto the optical fiber, or if the flat tape is warped vertically or horizontally, the stress applied to the optical fiber will be uneven, causing micro-bends in the optical fiber and causing transmission problems. Increased losses! f: Maneku. Also, if it warps, could it be due to lamination of tape core wires or external pressure? A problem arises in capturing the transmission loss, that is, in the lateral pressure characteristics. Koa 5
In order to obtain a uniform fabric coated with ultraviolet curable resin, we have decided to adopt a coating method such as coating with felt impregnated with ultraviolet curable resin or extrusion coating using die casting. Regarding the warping of Chi 7, the volume shrinkage (6 to 10
%)? The problem was solved by determining the optimal positioning of the ultraviolet irradiation lamp. Y rx In other words, in the case of a single-fiber wire, the 'IJIL cover is circularly symmetrical with respect to the glass of the central optical fiber, so non-uniformity in the initial amount of ultraviolet irradiation hardly causes any problems in maintaining the shape. However, in the case of a flat tape that is subject to the present invention, Fig. 4 1 and b
Step 5 shown in step 5 is to irradiate ultraviolet rays uniformly from the left and right or top and bottom of the flat surface, preferably from the entire circumference! Pka
I found that.

17 and 17' indicate ultraviolet irradiation lamps. This is because the thickness of this type of tape is generally between CLI and 1-state thickness.

By irradiating ultraviolet rays from one flat side, it is possible to finally penetrate the inside and cure the resin sufficiently, but when irradiating from one side, the amount of ultraviolet rays when passing through the resin between the irradiated side and the long side is small. is absorbed, causing temporal non-uniformity in the irradiation amount between the irradiated surface and the back surface, causing the resin on the irradiated surface to harden and shrink quickly, causing it to warp toward the irradiated surface. As the ultraviolet curable resin, urethane acrylate, epoxy acrylate, polyester acrylate, polybumediene acrylate, silicon acrylate, etc. are used.

Figure 5 shows B of UV-curable urethane acrylate resin.
A sheet 2 with a thickness of 0.0 pm was prepared, and the relationship between the related physical properties and the amount of ultraviolet light for curing was disclosed.

Here.

Ultraviolet light jt: Use a meter for ultraviolet light 1.

Gel fraction: This is one index of resin curing and is calculated using the following equation.

G is the weight of the hardening sheet, G! The cured sheet is immersed in methyl ethyl ketone, the uncured portion is extracted with a Soxhlet, and the dry weight and tensile modulus (Young's modulus) of the cured portion are calculated.
: JIS-K・7115 (Tensile speed 5 tug 7
) Volumetric shrinkage rate: Measure specific gravity and calculate from the following formula.

P2-ρ1 Volumetric shrinkage rate = -X 100 (%) P! ρi is the liquid specific gravity before curing, P! is the liquid specific gravity after curing.

From Figure 5, as the amount of ultraviolet light increases, the gel fraction (hardening degree)
increases, the volume shrinkage rate also increases, and the tensile modulus (Young's modulus) follows suit. The volume shrinkage rate has a good correlation with the gel fraction.

In other words, in the case of tape core wire, if the irradiation dose is high on one side, the resin applied to the irradiated surface will harden and shrink first, and the elastic modulus of that part will inevitably increase, so the irradiated surface will not be affected by a large force. It shrinks and warps on one side of the tape, and even after it is cured by irradiating the back side with the same type of ultraviolet rays, it does not return to its original shape. From the above, at the early stage of curing (the stage where the gel fraction or volumetric shrinkage rate is +2!), it is necessary to irradiate at least both flat surfaces with approximately the same amount of ultraviolet rays. Note that this phenomenon also applies to electron beam irradiation-curable resins.

Specific examples will be described below.

A GI type optical fiber with a core diameter of 50 μm and a cladding diameter of 125 μm is coated with UV-curable urethane acrylate resin (inner layer tensile modulus (L1Kq/m), outer layer tensile modulus 413
Kg/+u') was coated to prepare an optical fiber wire having an outer diameter of 270 μmφ, and a 5-core tape core wire was manufactured using the manufacturing process explained in FIG. The ultraviolet curing resin used to make the tape is a urethane acrylate resin with a tensile modulus of 45Kq/w.The irradiation lamp is BOW/
Using a high-pressure mercury lamp with a thickness of 450 μm and a width of 1500 μm.
A µm tape core wire was prepared. The irradiation conditions are shown in the table below.
The shape and transmission characteristics were evaluated under different conditions.

In addition, in the table, is the transmission loss the average value of 5 cores? show.

From the results shown, it is clear that the method of irradiation with ultraviolet rays has a large effect on the production of ribbon cores. In the present invention, it is an important requirement to perform irradiation on both flat surfaces fairly uniformly at the initial stage of curing (the stage at which the gel fraction or volumetric shrinkage rate is saturated). In addition, when forming into a tape by applying multiple layers, it is necessary to set the curing conditions by paying attention to the resin portion having a large tensile modulus. In general, the saturation dose for tensile modulus is 15
Step 5 shown in the figure is larger than the saturation photoelectricity of the gel fraction and volumetric shrinkage, but it is clear that once the gel fraction and volumetric shrinkage are saturated, no deformation will occur even if irradiated only from the left bend. did.

Effects of the Invention In the above-mentioned process 5, according to the present invention, a tape-shaped optical fiber core having a thin layer structure can be manufactured without causing deformation in the shape of the tape core wire, and is suitable for optical subscriber line systems, etc. It is suitable for multi-core cable configurations and is highly effective.

[Brief explanation of drawings]

1a, b, and e are cross-sectional views of examples of tape-shaped optical fiber core wires, and FIG. 2 is a process explanatory diagram of the manufacturing method of the present invention,
Figures 3a and 3b are cross-sectional views of an embodiment of the ribbon core manufactured according to the present invention, Figures 4a and 4b are diagrams illustrating an embodiment of the ultraviolet irradiation method, and Figure 5 is the amount of ultraviolet light and related physical properties. FIG. 1... Extruded tape core wire, 2... Protective coating, 5...
・Optical fiber, 4... Laminated tape core wire, 5...
Adhesive tape, 6... Pipe-shaped member, 7, 8, 9.
...Coating, 10... Supply device, 11... Concentrator, 12, 12'... Resin coating device, 15, 1! l
'...Curing device, 14... Winding machine, 15... Element wire group, 16... Tape core wire, 17, 17'... Ultraviolet irradiation lamp patent applicant Sumitomo Electric Industries, Ltd. (1 other person) Agent: Patent Attorney Tamamushiku 5th Section 1 Figure α b 3rd [i21 s

Claims (1)

[Claims] A plurality of optical fibers or fiber optic fibers each having a protective coating are arranged adjacent to each other, and an ultraviolet curable resin is applied to the outer surface of the array to form a flat tape-shaped body. A method for manufacturing a tape-shaped optical fiber core comprising the step of simultaneously irradiating at least both flat surfaces of a shaped body with a uniform amount of ultraviolet rays to cure the ultraviolet curable resin.