JPS5915907A - Production of plural-cored optical fiber bundle - Google Patents

Abstract

PURPOSE:To form economically a titled bundle having a collective covering contg. plural optical fibers at a high density by applying a primary coating on the optical fibers spun from plural pieces of base material rods then bundling the fibers and applying a secondary covering thereon. CONSTITUTION:Respective optical fibers 1 obtd. by melting and spinning simultaneously plural pieces of base material rods 10 disposed in parallel in a holder 11 in a heating furnace 12 are conducted into a coating die 13, and a primary covering resin (e.g.; silicone resin) 14 is coated thereon, whereafter the fibers are introduced into a curing furnace 15, where the fibers are heated or UV rays are irradiated thereto to cure the resin, thereby obtaining respectively discrete strands 3. Such strands 3 are then conducted into a die 16, and while the strands are densely bundled, a secondary coating resin 17 is coated thereon. The coated fibers are introduced into a curing furnace 18 where the fibers are heated or UV rays are irradiated to cure the resin, thereby forming a plural-cored optical fiber bundle 8. The fiber bundled is taken up on a take-up device 20 via a pulley 19.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a T6 method for economically producing optical fiber bundles (units) for telecommunications in which multiple σ) optical fibers are housed in high density.

The original fiber, which has been developed in recent years as a communication medium, has transmission characteristics that far exceed those of conventional copper wire pairs, and has the features of a small diameter, number of wires, and non-induction. .

The structure of the T-optical cable, which takes advantage of the stiffness characteristics, consists of a large number of optical 7-iper fibers gathered together at high density, and the cable plain wood is made of small diameter fibers.
In addition to becoming a @ rat, it is important to have an outlet for economicization.

Despite the above-mentioned advantages, the original fiber has a serious disadvantage, which is a problem peculiar to glass, which is a brittle material, that is, if there is a defect, the strength is extremely low and it becomes easy to break. Unlike copper wire, optical fiber cannot be handled as a bare wire, and it is necessary to apply a reinforcing coating immediately after spinning from a base material to prevent surface defects from occurring.

This coating is referred to as a primary coating, and is wound on a drum in the state of a conventional original fiber number (strand) and prepared for the n1-th manufacturing process. However, in such a single-core wire, there is a weak part (about i (/J) of the average strength that occurs during each process despite the area ratio,
There is a big problem in that the yield rate of g-frame manufacturing is low, and the fragility increases during winding on a drum, storage, and handling.

In order to increase the density and reduce the cable diameter as described in Trd, it is necessary to form a bundle (unit) in which a large number of optical fibers are concentrated at high density. In the conventional high-density unit, multiple pre-manufactured nT-strand drums are installed on the production line, and then a secondary coating is applied all at once using an extrusion method or the like to condense each IP:, W. It is manufactured by the method. However, in this case, it is necessary for each strand to withstand the tension during manufacturing, and if even one strand breaks, manufacturing becomes impossible, so the tension must be kept as low as possible, taking into account the fragile parts of each strand. However, compared to the case of copper wire, there are problems in that tension control during manufacturing is complicated, manufacturing speed is slow, and costs are high. Also, make sure that the primary coating of the wire is
Since the wire must be combed, there is a problem in that the diameter of the wire becomes thicker, which limits the ability to increase the density.

A manufacturing method in which 10,000 optical fibers are bundled and coated all at once in the primary coating stage was also devised (Japanese Patent Laid-Open No. 55-88
180), but KoT1. G:tI/Nbkl)
6 t< Concerning a bundled fiber. Bundled fibers cannot be used as individual optical fibers as communication transmission lines, and are different from the present invention not only in the field but also in the manufacturing process.

In addition, conventionally, multiple optical fiber cores are embedded in the cladding and integrated into a T-compound optical fiber and its spinning method has been devised, but the fragility of the fine fiber core is exactly the same as that of a single fiber. However, there was a big problem, and the manufacturing method involved the spinning process, and the σJ was also invented by JA.

X invention G: In order to solve the problem described in t nii
/J Immediately after spinning the optical fibers individually, each n/th order is applied to the strands to tdI! In a continuous process, each strand 1131 is
1 is bundled together and then coated with a secondary coating, so the fragility of each strand is not a problem.1 Moreover, the process can be significantly shortened, making it more economical. This is the purpose.

Figure 1 shows an example of the structure of the Shinshin optical fiber unit that is the manufacturing target of the present invention, and includes (a), (b) G1 flat type (one fiber), (c), (d).
I11 a; +6° 1G-1 optical fiber, 2 is the primary coating, 4 is the secondary coating in close contact with 2, A is the adhesive resin, 5 is the 62nd coating with thermoplastic ceramic resin, 6 is the film, 7 is the core material. Figures 2, 3, and 44 show embodiments of the present invention σ], in which 8&i is a plain jacket, 8 and 9 are multi-core units, lOG: is a base material, jl is a base material, rod 11 is a base material holder, and 12 is a heating element. furnace, 18
11 liquid, 15 hardening furnace, 16 focusing/coating die, 17 resin liquid, 7' welding resin liquid, 18 hardening furnace, 19 pulley, 201 Ma winder, 21G:t7'-IJ, 22G1 resin extrusion device m
, 284 is a resin, 24 is a trough, 25 is a film drum, 26 is a film, 27 is a wrapping die, and 28 is a curing furnace.

First, the structure and operation of the present invention will be explained with reference to FIG. A required number of base material rods are arranged in parallel by a holder 11, and each base material rod IO is simultaneously melted and spun in an IJO thermal furnace 12. If there are a large number of base material rods and they cannot be heated all at once in the same heating furnace, a plurality of heating furnaces may be used and the mother rods may be divided into several bundles. The spun optical fibers IG are simultaneously guided to a primary coating resin coating die 18, and after being coated with a secondary coating resin 14TI, they are passed through a curing furnace 15 where the primary coating resin is cured individually. becomes the strand 8. The same resin as the conventional resin for single-core fibers can be used as the f-coat M resin 14, such as thermosetting resin such as silicone resin, urethane resin, epoxy resin, or epoxy acrylate that hardens by ultraviolet irradiation. If □ 14, which is equivalent to s8 resin, is thermosetting, 15 is a heating furnace, and if 14 is ultraviolet curable, 1
5 is used as an ultraviolet irradiation furnace. Compared to the primary coated O 8 Gmi optical fiber, the occurrence of glass surface defects is suppressed by 1°, so the strength is significantly increased by slight contact. Deterioration T also known as G-
1, but there is a small probability that it has some vulnerable items. Therefore, each 8t wire is guided to a die 16 and tightly focused, coated with a co-coating resin 17, and passed through a curing furnace 18 to a second
Next, the coating resin is cured, and each blade root is coated all at once. 2
Next, the coated core unit 8 has a warped surface as shown in Fig. 1 (a) and (C), and the mechanical tensile strength is Inevitably, the strength is N times or more the strength of the strand.

This first thing. To explain this in detail, not only is the average strength N times higher, but even if there is a weak defect in a certain wire, the other wires maintain their strength, so even if a single wire has a low strength The strength difference is almost completely eliminated. Therefore, regarding Jushin unit 8, J pillar center: J! , No proof test (screening...usually carried out with a load of several hundred grams) as in #A is completely unnecessary. You can take it away. This 11-fiber unit will be assembled roughly at hpt1 in the next cable production process, but because it has extremely high strength, high-speed assembly can be achieved with simple tension control.

In the above steps, the thickness of the primary coating is selected in relation to the physical properties of the gift resin, but it is appropriate to set it to several microns to several tens of microns. If this primary coating is omitted, the optical fibers 1 will come into contact with each other bare, damaging each other's surfaces and significantly deteriorating the strength, and each fiber will be separated at the end of the cable. becomes difficult to handle. In the case of single-method loaded strands, even if the secondary coating is removed at the terminals, each strand maintains its strength as a single-core strand, so it is easy to handle them independently.

FIG. 3 shows an essential embodiment of the manufacturing method of the present invention using a thermoplastic resin in the subsequent secondary coating process. The steps up to the stage of strand 8 are the same as the embodiment shown in FIG. 7 strands 8 after primary coating treatment
It goes without saying that just before this, a die T is closely focused into a predetermined shape for each wire furnace. 2B is a thermoplastic that becomes molten when heated! ! 11 resin, extruded by 22 screws, and such an extruded unit is heated with hot water,
When cold water is passed through the trough z4, several parts are hardened and the four-core unit 8 is completed, so it is only necessary to wind it up with the winder 20.

In FIG. 3, the process 2 after the strands is shown as a horizontal type, but since the strands 8 will not break even if they come into slight contact with the pulley 21, a pulley or the like is placed in the middle, and each device is It is possible to increase the capacity. In particular, when performing high-speed coating with thermoplastic resin, it is necessary to remove the cooling part using a trough, etc., so if you try to do it all on a vertical line, the sieve of the entire device will become extremely high.
It is uno. For this reason, the line structure Et as in this embodiment is
c, &i have important meanings.

Next, Fig. 2 shows an example of the present method of making a film in which a continuous film is deposited, and is the same as the example shown in Fig. 2 up to the stage of strand 8. This embodiment is suitable for manufacturing a unit in which the strands are formed into a sandwich-like shape using a film 6, as shown in FIG. 1(b). After converging each strand 8 with the die 16 and applying the adhesive robe 17 at the same time, supplying the film 26 to the wrapping die 27, sandwich the strand array between the films, and connect the film and the strand array with MIN resin. It becomes one. The film for the mouth was produced in a completely different process.
It is possible to use T6 particles with the desired physical properties. For example, if you use a plastic or metal with a crystalline elastic modulus and a small coefficient of thermal expansion, you can improve the indirect reliability and transmission characteristic stability.
4).

In addition, in the example of FIG. This is to have the same effect as that of the film.The core material is inserted, for example, at the stage of the wire 8 in FIG. By the way, the dimensions of each fiber in the control unit are 1u.
Although it is necessary to control the spinning speed, since the spinning speed is the same for each fiber, it is effective to individually control the feeding speed of one base material rod. For this reason, the feed deviation control of each base material rod is performed at the base material holder 11 as necessary. This is because the integrity of the cloudy mother M rondo is the same as above, and as explained above in the above, the convergence unit conversion machine is provided in succession to the G masu fabrication process of the present invention. , a high-strength unit with negligible fragility in each strand is produced in an integrated process immediately after spinning, eliminating the problem of fiber strength when making N1 cables, and significantly shortening the process compared to conventional manufacturing processes. Because it is made of silk, it has the great effect of reducing manufacturing costs. In this way, Invention X has extremely large technical and economical effects, and will make an extremely large contribution to the practical application of optical fiber communications in the future.

[Brief explanation of drawings]

Figures 1 (a) to (d) are diagrams showing examples of the number of fibers in a pure-core optical fiber unit, and Figures 2, 3, and ψ are all T diagrams showing embodiments of the present invention. . 1... Optical fiber, 2... Primary coating,
8...Cable wire, 4...Secondary covering, 4'.
...Adhesive resin, 5...Secondary coating, 6...
...film, 7...center u, 8.9...
...Multi-core unit, 10...Base material rod, l
l... Base material holder, 12... Heating furnace,
18... Coating die, 14... Resin liquid,
15... Curing furnace, 16... Focusing and coating die, 17... Resin liquid, 17... Adhesive resin liquid, 18... Curing furnace, 19... Pulley, 20... Winder, 21... Pulley, 2z... Extrusion device, 28... Resin , 24...Trow, 25...Film drum, 26...Film, 27...
Bound die. 28...Curing furnace. Applicant Nippon Telegraph and Telephone Public Corporation Figure 1 (a) (b) (., (CI) Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) Simultaneously heat and draw multiple base material rods.
Then, following the step of spinning into individual optical fibers and forming a primary coating by applying and curing a t-order coating material to each fiber, each optical fiber with a 1-order fyt is carefully attached. A method for manufacturing a multi-core optical fiber bundle, comprising the step of converging, applying a secondary coating material, and curing by heating or ultraviolet irradiation to form a secondary fiber to form each fiber. . (2) Simultaneously heat and draw multiple base material rods,
Each fiber is spun into individual optical fibers.
Continuing with the step of forming the first-order fibers by applying and curing the order covering material, each f-order fiber is tightly focused, and a secondary coating of thermoplastic resin is formed to separate each party fiber. Batch T process kMT, distribution characteristics and T
14. Method of manufacturing 6-strand 6-element fiber collection. (3) Several sets of base material rods are heated and plumped at the same time,
Step 1: Spinning into individual 'XJ7 fibers, applying primary wl grafting to each optical fiber and curing.
Continuing with the process of forming the optical fiber 4, a process of closely focusing each order-covered optical fiber, applying adhesive and wrapping it with a film is carried out to bundle each optical fiber together. A method for manufacturing a multi-core optical fiber bundle characterized by M.