JP2996481B2 - Method for manufacturing fiber reinforced curable resin spacer for supporting optical fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application >> The present invention relates to an optical fiber supporting spacer used for protecting an optical fiber from an external force and a method of manufacturing the spacer.

<< Conventional Technology >> Since an optical fiber is weak against an external force, a spacer having a plurality of grooves on the outer periphery is used as an element of the optical cable to protect the optical fiber from the external force.

As this type of spacer, a spacer in which a tensile line is arranged at the center and a spiral groove is formed on the outer periphery thereof by a thermoplastic resin is generally used.

However, when the overall outer diameter of this type of spacer is small, the thermoplastic resin forming the rib does not contribute to the tensile strength, so the tensile strength is insufficient, and the optical fiber may not be effectively protected. .

In addition, thermoplastic resins have a large linear expansion coefficient, for example, high-density polyethylene, which is frequently used for spacers, is on the order of 10 ^-4. Even if a product made of GFRP) is used, the thermal expansion coefficient is offset by the large thermoplastic resin, and the thermal expansion coefficient becomes high as a whole.

Furthermore, the ribs made of thermoplastic resin undergo a large deformation with respect to compression, so that it is necessary to make the groove for the optical fiber large, and the outer diameter of the spacer tends to be large, the heat resistance is poor, and the optical fiber overhead It is not suitable for applications requiring heat resistance, such as the ground wire (OPGW).

On the other hand, in order to overcome the disadvantages of the physical properties of the spacer due to the thermoplastic resin, in order to manufacture a spacer using a fiber-reinforced thermosetting resin, a conventionally known method, for example, a pultrusion method in a mold or the like, requires a mold. The problem arises that the take-up resistance in the inside becomes large, and when trying to form a spiral groove,
It is necessary to carry out pultrusion in a mold having a spiral groove, and there is a problem that the take-up resistance further increases.

Accordingly, the present inventors have diligently studied a novel method of manufacturing a spacer made of a fiber-reinforced curable resin (hereinafter referred to as FRP) that does not require a pultrusion molding method in a mold, and have completed the present invention.

<< Structure of the Invention >> The structure of the present invention that can solve the above-described problems is a continuous reinforcing fiber group divided according to the core area of the spacer to be obtained and the cross-sectional area of each rib and bundled for each required number. It is characterized by impregnating with an active energy ray-curable resin, drawing and forming each of them into a predetermined shape, then drawing them into the final cross-sectional shape of the spacer while uniting them, and then hardening by passing through an active energy ray irradiation device. .

The reinforcing fibers used in the present invention are in the form of long fibers having high strength and low elongation and having a reinforcing effect, such as glass fibers, aromatic polyamide fibers, carbon fibers, and ceramic fibers. As the curable resin, a resin curable by an active energy ray such as an ultraviolet ray, a visible ray, or an electron beam, for example, in the case of an ultraviolet curable resin, a vinyl ester-based resin is preferable from the viewpoint of heat resistance and economy.

The division of the continuous reinforcing fibers prior to the impregnation of the uncured curable resin is performed according to the cross-sectional area of the core (central portion) and the rib portion based on the final shape of the spacer to be obtained. The number derived from calculating the number calculated from the fiber content is defined as one group.

After each of these divided reinforcing fiber groups is impregnated with an uncured active energy ray-curable resin, the excess resin is sequentially drawn and the final drawn cross-sectional area in the divided state is the equivalent cross-sectional area of the product. After about 100-110%, they are combined and drawn again by the final drawing die to the equivalent sectional area of the product.

Next, a curing device corresponding to the curable resin material using the same, for example, when an ultraviolet curable resin is used, is passed through an ultraviolet irradiation device or the like to cure the uncured resin, and the FRP spacer is removed. obtain.

The above steps are sufficient for obtaining a linear groove parallel to the longitudinal axis of the spacer, but the following method may be used for obtaining a spacer having a spiral groove.

The final drawing die is arranged on the entrance side of the active energy ray irradiation device, and a non-rotating exit guide corresponding to the shape of the spacer is provided on the exit side. Between the length L between the drawing die and the exit guide, Twist may be added to the drawn product according to the helical pitch, cured in an active energy ray irradiation device, passed through the outlet guide, and subsequently taken out by a rotary take-up machine.

The active energy rays include ultraviolet rays, visible light rays, electron beams, and the like, and the curable resin and the composition thereof may be selected so as to be curable by these energy rays.

In the curing of the uncured resin, a catalyst responsive to these may be used in combination so that, for example, ultraviolet rays and far infrared rays can be used in combination.

<Operation> According to the method of manufacturing the FRP spacer of the present invention, since the drawing at the uncured stage is divided into a plurality of pieces and then integrated, the density of the reinforcing fibers becomes almost uniform and a good shape is obtained. Since it can be obtained and can be cured and molded without using a drawing die, there is no problem of drawing resistance in the die which has been a problem in the past, and a spacer having a spiral groove requires a special die or the like. It can be manufactured freely without using it.

The spiral groove is formed by twisting the uncured molded body between the final drawing die on the entrance side of the active energy ray irradiation device and the guide on the exit side, adding twist, and curing the cured part to the fixed exit guide. When it is passed, in the irradiation device, a torsional force is propagated to the uncured portion side, and twist is continuously added, so that a beam having a predetermined helical pitch is obtained.

In addition, since an active energy ray-curable resin is used, the surface cures relatively quickly, and a stable final product can be obtained.

<< Embodiment >> Hereinafter, a preferred embodiment of the present invention will be described.

Example 1 An FRP spacer S having the shape shown in FIG. 1 was manufactured as follows.

Twenty 280-tex glass yarns A1 were prepared and divided into four blocks, each having five blocks for the central core and four ribs.

For each of the four divided fiber groups, 60 parts of a vinyl ester resin (trade name: ESTA-H-2000, manufactured by Mitsui Toatsu Chemicals) as an ultraviolet curable resin, and hexanediol diacrylate (Nippon Kayaku) as a crosslinking component Made: Kayarad HDDA) 20
Parts, N-vinyl 2-pyrrolidone 20 as a high boiling point reactive diluent
Part, photopolymerization initiator (Ciba Geigy: Irgacure 65
1) Impregnated with an uncured resin 1 composed of 3 parts and 2 parts of a thermosetting catalyst (manufactured by Kayaku Akzo: Kyaptyl B), and then through five square holes as shown in FIG. 2 (A). After forming each of the squares through a drawing nozzle 2A having a side of 0.95, 0.9, and 0.85 mm, each of the five drawn molded bodies is formed into a second area having the same area as the total area of the drawing dies of 0.85 mm. It was passed through a cross-shaped throttle nozzle 2B shown in FIG.

Subsequently, after passing this through the final drawing die 2C shown in FIG. 2 (C) corresponding to the product shape, a UV irradiation device 3 (Oak: QR4000) having a length of 750 mm and a thermosetting material having a length of 1500 mm Pipes 4 are connected in series, and the temperature in the former apparatus is set to 150
C., the latter was passed through a curing device in which the temperature in the pipe was 300.degree. C., cured at a speed of 6 m / min, and wound around a take-up drum 6 by a belt-type take-up machine 5. FIG.

The obtained linear grooved FRP spacer S has a glass fiber volume content of 63%, a tensile strength of 496 kg and a tensile strength at elongation of 0.2% of 1%.
It has a minimum bending diameter of about 100 mm at 8.8 kg, 43 kg at 0.5% elongation, and 85.5 kg at 1% elongation, and has a good shape and sufficient performance as an optical fiber supporting spacer.

Comparative Example 1 Compared with the above-described embodiment, the draw die was formed into a cross shape from the beginning and successively formed by drawing, and a spacer was obtained in the same manner as in Example 1 except for the above. The obtained spacer had a bad shape and could not be put to practical use.

Example 2 After drawing under the same conditions as in Example 1, the distance between the final drawing die 2C and the exit side guide 10 of the ultraviolet irradiation device 3 was increased.
During this time, the uncured molded body is twisted twice, guided to the outlet side guide 10, subjected to twist addition and partial curing in the ultraviolet irradiation device 3, and then subjected to the heat curing pipe 4.
To complete the curing, and the film was wound up by a rotary winder 6 'while being taken up by a rotary winder 5' rotating in synchronization with the spiral pitch. The obtained FRP spacer had a spiral pitch of 400 mm. This spiral spacer also had a good cross-sectional shape and was sufficiently suitable for practical use.

<< Effects >> As described above in detail in the examples, according to the method for manufacturing an FRP spacer for supporting an optical fiber of the present invention,
Molding can be performed in a non-contact state with the mold without relying on a drawing method in a mold required for the production of this type of product in the past, so that problems such as an increase in take-up resistance can be solved and a spiral groove can be solved. Can be manufactured relatively easily.

[Brief description of the drawings]

FIG. 1 is a sectional view of the FRP spacer obtained in Example 1, FIG. 2 (A, B, C) is a schematic view of a drawing die used in Example, and FIG. It is explanatory drawing which shows an example of a process. A1… Glass yarn (reinforcing fiber) 2A ～ 2C …… Drawing die 3 …… Ultraviolet irradiation device (active energy beam irradiation device) S …… FRP spacer

Continuation of front page (56) References JP-A-62-174134 (JP, A) JP-A-61-179407 (JP, A) JP-A-61-10440 (JP, A) (58) Fields investigated (Int) .Cl. ⁶ , DB name) B29C 70/00-70/88 G02B 6/44

Claims (4)

(57) [Claims] An active energy ray-curable resin is impregnated into a continuous reinforcing fiber group divided according to a required number of pieces and divided according to a cross-sectional area of a core portion and a rib of a spacer to be obtained,
Each of these is drawn into a predetermined shape, then drawn into the final cross-sectional shape of the spacer while being united, and then cured by passing through an active energy ray irradiation device. Manufacturing method of spacer. 2. The helical pitch of the helical spacer obtained after curing while applying a twist corresponding to the helical pitch between the final drawing die on the entrance side and the guide on the exit side of the active energy ray irradiation device in the curing step. 2. The method for producing a fiber-reinforced curable resin spacer for holding an optical fiber according to claim 1, wherein the spacer is taken by a rotary take-up machine that rotates in synchronization with the above. 3. The method according to claim 1, wherein the active energy ray-curable resin is an ultraviolet-curable resin. 4. An optical fiber carrier according to claim 3, wherein a UV curable catalyst and a thermosetting catalyst are used in combination, and the surface is pre-cured by ultraviolet rays and then completely cured by heat curing. A method for manufacturing a fiber-reinforced curable resin spacer.