JPH0547807B2 - - Google Patents

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] The general method for manufacturing tape-type optical fibers is to align a plurality of unwound optical fibers in width and align them in parallel, and then apply ultraviolet curable resin (hereinafter referred to as UV resin). Then, the applied UV resin coating layer is irradiated with ultraviolet rays to cure it, thereby obtaining 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 the tension of each core wire is controlled. Attempts have been made to improve the shape and arrangement of the width-adjusting rollers, but these methods are not fully satisfactory as countermeasures against current parallelism defects.

Further, 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 aims to improve the parallel state of the fibers in the production of tape-type optical fiber cores and to prevent tearing of each core wire during terminal processing work. The present invention aims to provide a manufacturing method for obtaining a tape-type optical fiber core wire that can be easily performed.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention arranges the unwound optical fiber cores in parallel and arranges the passages of each core in parallel by opposing corrugated surfaces. Pass through a primary coating tank equipped with a die with narrow spaces between each passage, apply a primary coat to the surface of each core wire in a parallel state according to the shape of the die, and apply this coat with a gel fraction of 40~
It is manufactured by a step of semi-curing to 60%, followed by a step of applying a second coat and fully curing it.

[Operation] In the method of the present invention configured as described above, optical fiber core wires arranged in parallel are passed through a primary coating tank, and each core wire is coated with a primary coat in a shape corresponding to the shape of the core due to opposing corrugated surfaces. Apply this coat to a gel fraction of 40
Since it is semi-hardened to ~60%, it is placed in parallel with each core wire so that it can be straightened. That is, in the primary coated state, the connecting portion between each core wire has a constricted shape, and since this coat is in a semi-hardened state, the parallel state can be easily corrected. Subsequently, a second coat is applied and this coat is sufficiently cured, so if the core wires are in poor alignment after the first coat, they will pass through the die during the second coat. As a result, the parallel state is corrected, and thereby a tape-type optical fiber core wire with good parallel state of the core wires can be obtained. In particular, if the primary coat layer is in a semi-cured state with a gel fraction of 40 to 60% as described above, it is possible to correct the parallel state as described above, and moreover, when the secondary coat layer is cured, No hardening distortion occurs.

In addition, since the coat is divided into the primary and secondary coats, the primary coat is semi-cured, and the secondary coat is sufficiently cured, the normal protection is sufficient and the tearing of the core wire during terminal processing etc. is prevented. This can be done more easily than when all the coat layers are sufficiently cured at once. In particular, as mentioned above, by using a die for the primary coat that narrows the passage between each core wire by having opposing corrugated surfaces, the primary coat has a constricted shape at the connecting part between the parallel core wires. and
This, combined with the semi-curing of the primary coat, makes it easier to tear the core wire during the termination process.

[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 cores f are fed out from the bobbin 2 of the supply stand 1.
is fed into the subsequent primary coating tank 4 while being width-aligned by a width-aligning roller 3 to narrow the gap between core wires.

The above-mentioned width adjusting roller 3 may be, for example, a roller 3a which is rotatably installed with its axis perpendicular as shown in FIG. A roller 3b whose axis is inclined in the dimension, or a roller 3c which is installed upright with a dimension corresponding to the thickness of the core wire and a difference in outer diameter in the part where the core wire passes, as shown in FIG. It is configured so that a plurality of core wires f are allowed to pass in contact with each other at intervals vertically so as not to contact each other.

Then, as described above, the primary coating tank 4 is
The core wires f entering the die pass through this primary coating tank 4 in parallel according to the shape of the die, and UV resin such as urethane is coated on the surface to the required thickness set according to the total thickness of the coating layer. coated. As shown in FIG. 4 (a), the die 5 of this primary coating tank 4 has a shape in which the passages for each core wire f are arranged in parallel with the corrugated surfaces facing each other, and the passages between each passage are narrowed. It is preferable to configure the coating so that each core wire is coated by applying the coating to each core, because parallel correction can be easily performed during the secondary coating described later.

Then, the core wire f exiting the primary coating tank 4 is passed 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 coating layer is gelled by ultraviolet irradiation. Semi-cure to an extent of 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 f semi-hardened in the above step is then passed through the next secondary coating tank 7, where the parallel state of the core fiber f is corrected by passing through a die and is coated with UV resin. Next coat is applied. The die 8 used in the secondary coating tank 7 has a flat through hole, as shown in FIG. 4 (b), so that it can be finished into a tape shape with a predetermined size.

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

In addition, the primary coating tank 4 and the secondary coating tank 7
The UV resin is circulated and supplied by a micropump (not shown). In addition, the primary and secondary coating tanks 4 and 7 have hot water holes 11 for heat retention in their peripheral walls with a double wall structure or the like so as to keep the resin viscosity in the tank constant as shown in FIG. 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 of course other
It may also be UV resin.

Further, the layer thicknesses of the above-mentioned primary coat and secondary coat vary depending on the diameter and number of optical fiber core wires, but are usually set to 1/2 of the total coat layer thickness. For example, when arranging four optical fibers with an outer diameter of 250 μm in parallel, the primary coat dimensions (external dimensions): 0.35 mm x 1 mm and the secondary coat dimensions (external dimensions): 0.4 mm x 1.1 mm.

In addition, as mentioned above, the amount of UV irradiation for the first coat and the amount of UV irradiation for the second coat are as follows: the gel fraction after UV irradiation of the primary coat is 40 to 60%, and the gel fraction after UV irradiation of the second coat is 95%. Set it to be around %.

For example, using urethane-based UV resin (brand: R3056 or R3050) manufactured by Japan Synthetic Rubber Co., Ltd. as the UV resin, a tape-type optical fiber core wire is prepared by arranging four optical fiber core wires with an outer diameter of 250 μm in parallel under the above-mentioned conditions. When manufactured, the parallel state of each core wire in the coating layer 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 primary coating is divided into the primary coating and the secondary coating using a special die with opposing corrugated surfaces. A tape-type optical fiber that is semi-cured to 40-60% and then applied with a secondary coat to provide good protection for each core, with good parallelism of the cores, and easy termination work. You can get the cord.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view showing an embodiment of the manufacturing method of the present invention, Fig. 2 is a perspective view illustrating width adjustment rollers, and Fig. 3 is a primary (secondary) coating tank. Fig. 4 [a], [b]
FIG. 2 is a perspective view illustrating the shape of a through hole of a die in each coating tank. 1... Supply stand, 3... Width shifting roller, 4... Primary coating tank, 5... Die, 6... Ultraviolet irradiation device, 7... Secondary coating tank, 8... Die, 9... Ultraviolet irradiation Device, 10... winding machine.

Claims (1)

[Claims] 1. The optical fiber cores to be fed out are arranged in parallel and passed through a primary coating tank equipped with a die in which the channels of each core are arranged in parallel with opposing corrugated surfaces and the distance between each channel is narrow. A step of applying a primary coat to the surface of the die in a parallel state according to the shape of the die, semi-curing this coat to a gel fraction of 40 to 60%, and following this step, applying a second coat and fully curing it. A method for manufacturing a tape-type optical fiber core, comprising the steps of: