JPH0240604A - Production of tape type coated optical fiber - Google Patents

Abstract

PURPOSE:To improve the protection of respective fibers and to improve the parallel state of the fibers by applying a secondary coat on a primary coat while the primary coat is held half cured. CONSTITUTION:Plural pieces (for example, 4 pieces) of the coated optical fibers (f) let off from bobbins 2 of a supply stand 1 are fed into a primary coating tank 4 while the interfiber spacings are narrowed by edging rollers 3. The fibers (f) are then arrayed according to the shape of a die and are passed through a coating tank 4. The surfaces of the fibers are coated with a UV resin of an urethane system, etc., to a required thickness during this time. The fibers (f) emitted from the primary coating tank 4 are then passed through a UV irradiation device 6 and the UV resin coating layer is half-cured to about the extent at which 40-60% gel fraction is attained. The fibers (f) are thereafter passed through the secondary coating tank 7 and is subjected to secondary coating of the UV resin. The fibers (f) emitted from the coating tank 7 is passed through the UV irradiation device 9 to sufficiently cure the resin to about 95% gel fraction. The fibers are then taken up on a take-up machine 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a tape-type optical fiber coated wire in which the parallel state of the optical fiber coated wires is good and the terminal processing operation is easy.

[Prior art] A general method for producing tape-type optical fiber cores is to align a plurality of unwound optical fiber cores in width and align them in parallel, and then coat them with ultraviolet curing resin (hereinafter referred to as UV resin). The coated UV resin coating layer is then cured by irradiating the coated UV resin coat layer with ultraviolet rays to obtain a tape-type optical fiber core.

In the above-mentioned conventional method for manufacturing tape-type optical fiber cores, in order to improve the parallel state of each core wire inside the UV resin coat, the tension of each core wire that is fed out and brought together in width is controlled, or Attempts have been made to improve the shape and arrangement of the width-adjusting rollers, but these methods are not fully satisfactory as a countermeasure for the current parallelism failure.

Furthermore, the UV resin coat described above requires a certain degree of thickness to protect the core wires, and since it is hardened, it is not easy to tear each core wire during terminal processing.

[Problems to be Solved by the Invention] In view of the above-mentioned circumstances, the present invention provides a method for producing tape-type optical fiber cores in which the parallel state of the cores is good and each core wire is easily torn during terminal processing work. The purpose of the present invention is to provide a manufacturing method for obtaining a tape-type optical fiber core that can be carried out in the following manner.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention includes a step of arranging the unwound optical fiber cores in parallel, applying a primary coat to each core wire, and semi-curing the coat. This process is followed by a process of applying a second coat and fully curing it.

[Function] The method of the present invention configured as described above applies a primary coating to each core of optical fiber cores arranged in parallel, semi-cures this coat, and arranges the cores in a state in which the cores can be straightened. Subsequently, a second coat is applied and this coat is sufficiently cured, so if the parallel state of the core wires after the first coat is poor, the parallel state can be improved by passing through the die during the second coat. As a result, a tape-type optical fiber core with good parallelism of the core wires can be obtained.

In addition, since the coat is divided into the primary and secondary coats, the second coat is semi-cured, and the second coat is fully cured, the normal protection is sufficient and the core wires are not torn during terminal processing. This can be done more easily than when all the coat layers are sufficiently cured at once.

[Example] Next, embodiments of the present invention will be sequentially described with reference to the drawings and an apparatus for use thereof.

A plurality of (four in the figure) optical fiber core wires (r) are fed out from the bobbin (2) of the supply stand (1),
The fibers are fed into the subsequent primary coating tank (4) while being moved by a width-adjusting roller (3) to narrow the distance between the core wires.

As the width adjusting roller (3), for example, the one shown in Fig. 2 is used.
As shown in (a), a roller (3a) is installed upright so as to rotate freely with its axis vertical, or as shown in (b) of the same figure, the axis is inclined with a dimension corresponding to the thickness of the core wire. A roller (3b) is used, or a roller (3c) is used, which has a dimension corresponding to the thickness of the core wire and is set upright with a difference in outer diameter at the core wire passage part as shown in (c) of the same figure. It is configured so that the core wires (f') are allowed to pass in contact with each other at intervals vertically so as not to contact each other.

Then, the core wires (f') that have been width-aligned and entered the primary coating tank (4) as described above pass through this primary coating tank (4) in parallel according to the shape of the die, and are coated with urethane-based etc. U of
The V-resin is coated to a required thickness set according to the total thickness of the coating layer.

The die (5) of this second coating tank (4) is shown in Fig. 4(a).
It is preferable to provide a passage for each core wire (f) and to coat each core wire accordingly, as shown in FIG. .

Then, the core wire (f') exiting the second coating tank (4) is
It passes through an ultraviolet irradiation device (6) using a mercury lamp (not shown) or the like as a radiation source, during which time the UV resin coat layer is semi-cured by ultraviolet irradiation to an extent that the gel fraction becomes 40 to 60%. However, in the lever state, since the coat is semi-cured, the core wires are held in parallel, but the parallelism can be corrected.

The optical fiber core wire (f
) is to pass through the next secondary coating tank (7), where the parallel state of the core wires (f) is not corrected by passing through the die and is then subjected to a secondary coating with UV resin. The die (8) used in this secondary coating 10 (7) has a flat through hole as shown in FIG. 3 [b] so that it can be finished or formed into a tape shape of a predetermined size.

The core wire (f) that has come out of this secondary coating tank (7) is passed through an ultraviolet irradiation device (9), during which time it is sufficiently cured, that is, the gel fraction after ultraviolet irradiation is, for example, around 95%. After curing to a certain degree, it is wound up using a winding machine (10).

Note that the UV resin in the secondary coating tank (4) and secondary coating tank (7) is circulated and supplied by a micro pump (not shown). In addition, the above-mentioned secondary and secondary coating tanks (
4) and (7), as shown in Fig. 2, hot water holes (11) for heat retention are provided in the peripheral wall of the tank with a double wall structure or the like so as to keep the resin viscosity in the tank constant. , hot water and the like are circulated and supplied to this hole through a piping system (not shown).

In addition, as the UV resin, urethane-based UV resin (for example, manufactured by Japan Synthetic Rubber Co., Ltd., brand: R3056 or R3050)
is preferably used, but other UV resins may of course be used.

Further, the layer thicknesses of the above-mentioned primary coat and secondary coat vary depending on the diameter, number, etc. of the optical fiber core wires, but are usually set to a layer thickness of 172 times the total coat layer thickness. For example, when arranging 4 optical fibers with an outer diameter of 250 μm in parallel, -thickness coat size (external shape): 0.35 Dragon x 1 l 11
1st secondary coat dimensions (outer diameter): 0.4 am
1.1 mm.

In addition, as mentioned above, the amount of UV irradiation for the next coat and the amount of UV irradiation for the second coat are as follows: Set the rate to be around 95%.

For example, as a UV resin, '7L/9 manufactured by Japan Synthetic Rubber Co., Ltd.
:/ series UV resin (brand: R3056 or HaR3050) was used to manufacture a tape-type optical fiber core in which four optical fiber cores with an outer diameter of 250 μm were arranged in parallel under the conditions described above. The parallel state of each core wire was good, and the tearing and separation work for each core wire at the end portion was also easier than with conventional products.

[Effects of the Invention] As described above, according to the manufacturing method of the present invention, the protection of each core wire is achieved by separating the first and second coats, semi-curing the first coat, and applying the second coat. It is possible to obtain a tape-type optical fiber core which is well-formed, has a good parallel state of the core wires, and is easy to perform terminal processing.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing an embodiment of the manufacturing method of the present invention;
Figures 2 (<) (B) and (C) are perspective views illustrating width adjustment rollers, Figure 3 is a cross-sectional perspective view showing an enlarged view of the primary (secondary) coating tank, and Figure 4 (a). (b) is a perspective view illustrating the through hole shape of the die of each coating tank. (1)... Supply stand, (3)... Width-aligning roller, (4)...-Next coating tank, (5)... Die,
(6)...Ultraviolet irradiation device, (7)...Secondary coating tank, (8)...Die, (9)...Ultraviolet irradiation device,
(10)... Winding machine. Patent applicant TAC Electric Wire Co., Ltd.

Claims (1)

[Claims] 1. The process of arranging the unwound optical fiber cores in parallel, applying a primary coat to each core and semi-curing this coat, and following this process, applying a secondary coat and fully curing it. A method for manufacturing a tape-type optical fiber core wire, which is characterized in that: