JPS582813A - Reinforcing method for sealed connection part of optical fiber core - Google Patents

Abstract

PURPOSE:To easily form a high-reliability reinforcement part by sheathing optical fiber cores with a transparent plastic pipe around the sealed connection part of the optical fiber wires, and changing the gap with an adhesive from the injection hole of the pipe. CONSTITUTION:A transparent plastic pipe 1 is made of high-density polyethylene and a low-temperature plasma treatment is carried out. Optical fiber cores 3 are sheathed with a pipe 1 and optical fibers 4 and 4 are butted and connected by being sealed. The pipe 1 covers the optical fibers 4 and 4 around the connection part 6 including plastic coating layers 5 and 5, and an epoxy resin adhesive 2 is injected from an injection hole 7, and is heated and caked. Consequently, an increase in transmission loss resulting from fluctuations of temperature and the breaking of a fiber are reduced to constitute a reliable reinforcement part easily.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a method for reinforcing an optical fiber core fusion splice.

As a method for connecting optical 7-eyeliner fibers, there is a so-called fusion splicing method in which the optical 7-eyeliner fibers to be connected are butted together and then heated and fused. In this case, it is necessary to remove the plastic covering layer of the optical fiber core, which serves to maintain the mechanical strength of the optical fiber core. For this reason, after light 7 Aipashin m* continuation,
It is necessary to reinforce the removed part of the covering layer. This contact M, l
As a reinforcing method for 111, it has been proposed to use a plastic reinforcing member. However, the S* elongation of the optical 7-A5 fiber core wire is very small (10"1-10-/"
C) There is almost no effect of temperature envy, whereas the reinforcing member is plastic and its ms elongation is large <io''S~1
0-'/''C), since the influence of temperature change is large on non-S,
When stress such as heat is applied, the reinforcing member expands and contracts. This allows localization of the optical fiber core.
This causes an increase in transmission loss, and furthermore, fiber breakage occurs due to the protrusion of the optical 7-iper core wire. In addition, the elasticity of the plastic reinforcing member is made of several hundred to i, ooo, and is smaller than the elastic modulus of the Hikari 7 Aiper core wire, which is 7.000Y;tK, so the reinforcing member is easily deformed by external force, and the Stress is applied to lIr1l! There is a risk of

The present invention has been made in view of the above-mentioned circumstances, and provides a method for reinforcing a highly reliable optical fiber core koji-fused joint with no increase in transmission loss or risk of breakage of the optical fiber. The purpose is to.

Hereinafter, the present invention will be explained in detail.

In reinforcing the optical fiber core IIWI splice according to the present invention, a transparent plastic snap pipe is fabricated by dielectrically heating and stretching a crystalline polymer. Then, a transparent plastic pipe was placed over the Hikari 7 Aipah core, with the fusion spliced part of the Hikari 7 Aipah element placed inside, so as to straddle the end of the plastic test layer, and an injection hole provided in the transparent plastic pipe was placed. The gap between the transparent plastic pipe and the optical fiber is filled with adhesive.

As the material for the transparent plastic pipe used in the present invention, crystalline polyesters such as polyethylene, polyoleain such as polyurethane, nylon, or polyester such as polyethylene terephthalate can be used.

Using these materials, transparent plastic pipes are made using extrusion methods. Next, by dielectrically heating and stretching this pipe, a transparent plastic pipe with a high elastic modulus and a low am tensile modulus is obtained.

With dielectric heating, the amorphous part of the polymer can be selectively heated and stretched, which suppresses the decrease in strength of the crystalline part, while the amorphous S
Stretching stress effectively works to enable stretching and orientation of high-strength fibers, allowing the elastic modulus to be high and the elasticity to be small. Transparent plastic pipes made of polymers that are difficult to bond, such as polyethylene-polyethylene terephthalate, can be made using a 111-100-degree plasma treatment process using gases such as helium or helium.
Adhesive properties can be imparted by surface treatment.

The bending agent used in the present invention is a thermosetting adhesive such as evo medium resin or urethane resin, or
Anaerobic gauze adhesive with 9' Atarita oil-based oligomer, or modified acrylic yarn string adhesive that can be attached for a short period of time (second
◎Adhe is called the next generation of modified acrylic adhesive.
sives, 8ept, kot(iqt
t)) or a cyano-based instant adhesive can be used.

However, if the viscosity during operation is too high, the filling of the first section in the transparent pipe will be incomplete, so it is necessary to use an adhesive with a low viscosity of 100 cps or less.

Hereinafter, the present invention will be specifically explained with reference to Examples. □ ・ [Example 1] Figure 1 shows the optical fiber core fusion splice 1 obtained by the present invention.
It is a diagram showing the reinforcement/structure of the 11M section. In this figure, reference numeral 1 is a transparent plastic pipe, 2 is an adhesive, 8 is an optical 7-iper core wire, number is an optical fiber bare wire, Sa plastic coating layer, 6 is a fusion splicing part, and 7 is an injection hole. To obtain this reinforced structure, first, a transparent plastic pipe 1tIi1 made of high-density polyethylene with a high elastic modulus and a low S** modulus is prepared by the method described above, and then this is subjected to a low-temperature plasma treatment.

In this case, the transparent plastic pipe lvc has an adhesive injection hole formed therein. Then, before connecting the optical fiber cores 8 and 8, a transparent plastic pipe 1 is molded to one of the optical fiber cores 118 and 8, and then the optical fiber element 114.
Butt them together and fusion splice the ends. Then, the transparent plastic ivy pipe 1 is placed so as to straddle the ends of the plastic covering layers 5, 5, with the fused gauze part 6 located inside.
A resin composition prepared by pre-mixing 1128,100 parts by weight of an epoxy resin adhesive (Ebiko, manufactured by Yuka Ciel Emmeishi Co., Ltd.) with 90 parts by weight of methylnaditutaic acid anhydride and 5 parts by weight of benzyldimethylamine from the injection hole)
was injected using a syringe. Visually check that the first section in the transparent plastic pipe is completely filled.
,Ta. The area was slightly heated with a heater to harden the adhesive.

According to such a reinforcing method, even if a load of 1 kg of optical fiber core K is applied to the reinforced part of the optical fiber core, the optical fiber core does not break, and it can withstand temperature cycles of -20°C to +60°C.
Even after 20 cycles, no breakage of the optical 7-IPA core wire occurred, and the increase in transmission loss was less than Q92 dB.

〔Example! ]

As shown in FIG. 2, in this embodiment, as in the first embodiment, the fusion spliced portion of the optical fiber core II8 is covered with a transparent plastic pipe l, and the space between the transparent plastic pipe 1 and the optical fiber 7 Aiper element 614 is A transparent plastic pipe 8 with a slot cut therein was inserted, and a cyanoacrylate-based adhesive 8 was filled into the gap between these members from the injection lower. The transparent plastic pipe 8 used in this example was made in the same manner as the transparent plastic pipe 1.

Thus, even with this reinforcing method, Example 1 and #111
11 effects were obtained, and a highly reliable reinforced portion was formed.

As explained above, according to the reinforcing method of the present invention, by using a transparent plastic pipe with high elasticity and low S* elongation, it is possible to reduce the external stress applied to the fiber connection part. This can prevent fiber core protrusion and stress propagation due to changes, increase transmission loss, and
It is possible to reduce the cost of cutting the eyelid. Therefore, there is an advantage that a highly reliable reinforcing portion can be easily formed.

Furthermore, the transparent plastic pipe of the present invention can be said to be an economically superior reinforcing square because the material cost is low and the manufacturing method is simple.

[Brief explanation of drawings]

FIG. 1 is a side sectional view IIi showing an example of a reinforcing structure for an optical fiber connection portion obtained according to the present invention, and FIG. 2 is a front sectional view showing another example of the same reinforcing structure. 1...Mountain/Transparent plastic pipe!・・・・・・１
1111 Part, 8... Optical fiber core, 4...
...Hikari 7 Aipa main body, 6...Plastic covering part, 6...Fusion splicing part, F...Injection hole. Applicant Nippon Telegraph and Telephone Public Corporation S1 diagram

Claims (1)

[Claims] (1) A transparent plastic pipe is produced by electrically heating and stretching the crystalline Girima T+S, and the transparent plastic pipe is made into a transparent plastic pipe. 1. Place the first matte part of the optical fiber element inside, cover it so as to straddle the end of the plastic ivy coating layer, and insert the first transparent plastic pipe through the injection hole provided in the transparent plastic pipe. 1. A method for reinforcing an optical fiber core-fusion splice II joint, characterized in that a VCLII adhesive is instantaneously filled between the optical fiber core and the IPA element. (1) As a reduction of $51, a patent characterized in that a thermosetting adhesive, an anaerobic adhesive, an acrylic adhesive, or a cyano-based instant adhesive of 1100 cp or less is used. Hikari 7 AIPA core - Reinforcement method for fusion splicing part.