JPH0445405A - Production of frp armored optical cable - Google Patents

Abstract

PURPOSE:To improve the properties of the armored cable and to reduce an initial cost as well as to save manpower by doubling and twisting an uncured FRP armoring wire on the outer periphery of an optical fiber cable in tight contact therewith and applying an outer layer coating layer on the outer periphery thereof, then setting the internal uncured thermosetting resin at the time of producing the above-mentioned optical fiber cable. CONSTITUTION:This production process has a 1st stage to obtain the optical fiber cable a2 by housing optical fibers into the grooves of a spacer a1 and forming a skin sheath on the outer periphery thereof, a 2nd stage to obtain the plural uncured armored bodies by impregnating the thermosetting resin in reinforcing fibers a31 and coating the fibers with a thermoplastic resin in the uncured state of the thermosetting resin, then solidifying the resin, a 3rd stage to form a coating layer by the thermoplastic resin after the plural armored bodies a3 obtd. in the 2nd stage are doubled and twisted while being supplied to the outer periphery to arrange the optical fiber cable obtained by the 1st stage at the center, and a 4th stage to respectively solidify and cure the coating layer and the thermosetting resin. The 1st to 4th stages are continuously executed. Finally, the optical cable a4 is taken up on a rotary winder 12 via a rotary take-off 40.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing an FRP armored optical cable having both high tensile strength and flexibility.

(Background of the Invention) In order to protect and strengthen the outer periphery of the cable, a plurality of fiber-reinforced thermosetting resin (hereinafter referred to as FRP) filaments are used to cover the outer periphery of communication and conductive cables for the purpose of reducing weight and making them non-electrical. The so-called armored cable covered with a material was developed in the 1980s.
It is publicly known from No. 364 and the like.

On the other hand, in recent years, optical fiber cables have been adopted as communication cables due to their high capacity and high speed communication properties.

Large-capacity optical fiber cables use a so-called helical spacer, which has multiple spiral grooves made of thermoplastic resin such as high-density polyethylene, around the outer periphery of the tensile strength wire, and the optical fiber core is inserted into these grooves. Alternatively, it is common to have an optical fiber tape in which the outer periphery is coated with a thermoplastic resin.

In addition, in order to protect optical fiber cables from external forces such as lateral pressure and tensile force, if the outer periphery of the optical fiber cable is armored with a high-strength wire material, the wire material should be attached to the cable after manufacturing the optical fiber cable. The material is then twisted around the outer periphery of the material and coated with an outer layer.

When armoring with FRP wire material is applied, the outer periphery of the uncured FRP is coated with thermoplastic resin, etc., in order to prevent stress cracks in the FRP, as described in the above-mentioned public notice. It is proposed to use
As such an uncured FRP armored wire, a composite FRP wire having a thermoplastic resin coating layer prepared by the method disclosed in Japanese Patent Publication No. 51-43501, which is an earlier application of the present applicant, is preferably used.

However, in the past, when sheathing with unhardened composite FRP wires, the manufacturing of the unhardened composite FRP wires and the process of sheathing them around the outer periphery of the cable were performed separately. Therefore, it takes a long time to store the uncured wire before using it, and it is required to have a long pot life, for example, one that can be used for about 30 days at room temperature.

Therefore, the present applicant has already disclosed a thermosetting resin composition for this kind of uncured linear material having a long pot life in Japanese Patent Application Laid-Open No.
-139872.

However, even with the thermosetting resin composition described in the same patent publication, the reinforcing fibers may become uneven or disordered in the composite uncured linear material once it is wound onto a bobbin, drum, etc. The strength after curing is about 20 to 30% lower than that of a composition containing styrene monomer as a crosslinking component, which is commonly used in FRP.

Furthermore, when manufacturing an optical fiber cable, it is necessary to store the optical fiber in the groove of the spiral spacer, and for this purpose, the optical fiber, etc. wound around a bobbin or the like must be rotated or It is necessary to rotate the spacer itself around its long axis, and when applying FRP armor, it is necessary to rotate the armor wire or cable itself, and in any case, the rotation device is forced to become more complicated and larger. Ru.

Therefore, the present inventors have diligently studied a method for manufacturing FRP armored optical fiber cables with high productivity that can suppress the above-mentioned problems, namely, the decrease in the strength of armored wires and the complexity and enlargement of equipment, and have developed the present invention. completed.

(Structure of the Invention) In order to achieve the above object, the method for manufacturing a fiber-reinforced thermosetting resin armored optical cable of the present invention includes storing an optical fiber in a groove of a spacer and forming an outer sheath around the outer periphery of the optical fiber. The first step is to impregnate reinforcing fibers with a thermosetting resin, and the thermosetting resin is coated with a thermoplastic resin in an uncured state, and then hardened to form a plurality of uncured armor sheaths. a second step of obtaining a body, and placing the optical fiber cable obtained in the first step at the center, and twisting them while supplying a plurality of armored bodies obtained in the second step to the outer periphery thereof. After the combination, a third layer is formed of a thermoplastic resin to form a covering layer.
and a fourth step of solidifying and curing the coating layer and the thermosetting resin, respectively.
It is characterized in that the steps are performed continuously. The reinforcing fiber material that can be used for the armor body of the present invention is not particularly limited as long as it has tensile strength, but continuous glass fibers, aromatic polyamide fibers, carbon fibers, nylon fibers, etc. Examples include synthetic fibers such as , polyester, and vinylon.

The fiber content is approximately 50 to 75 voN%, more preferably 55 to 70 vog%.

In addition, the thermosetting resin that is impregnated into the reinforcing fibers of the armor body is
Unsaturated polyester resins are common, but epoxy resins, phenolic resins, etc. may also be used.

The type of thermoplastic resin that covers the outer periphery of the reinforcing fibers impregnated with an uncured thermosetting resin is not particularly limited as long as it can be easily coated by melt extrusion, but generally, it is a flexible resin. Polyethylene-based resins and polyamide resins are recommended as flexible resins due to their properties, low-temperature resistance, and economic efficiency.

When manufacturing an FRP armored optical cable, the method for manufacturing an uncured composite armored body is based on the method disclosed in Japanese Patent Publication No. 51-43501 filed by the present applicant.
The number of armor bodies required for the cable to be obtained is simultaneously coated with thermoplastic resin, the coating layer is immediately cooled, and immediately thereafter the twisting process begins.

Twisting of the armored body is accomplished by storing optical fiber tape cores in the grooves of an optical fiber cable spacer, which is wound around a bobbin or the like and rotatably supplied in synchronization with a rotary take-up machine. Optical fiber cables that have been taped and sheathed are supplied to the center, and multiple armor bodies are supplied to the outer periphery via guides and twisted, then coated with thermoplastic resin, and then placed in a heat curing bath. This is done by the rotation of the rotary take-up machine, etc. in the process of hardening the internal resin of the uncured armor sheath and winding it up by the rotary take-up machine via the rotary take-up machine.

In addition, if the distance between the optical fiber cable spacer rotation supply device and the rear rotary take-up machine becomes long, there is a risk that twisting force will be applied to the spacer or optical fiber cable between them. For example, a rotary take-off machine may be additionally arranged as appropriate, for example, a sheathed fiber cable may be taken off and supplied by a take-off machine that rotates synchronously.

The tension T of each armor sheath when twisting the uncured armor sheath around the outer periphery of the optical fiber cable is the unit weight W of the reinforcing fiber used therein.

/m), it is preferable that T≧(9000xWx0.05)Xi/3 (g) from the viewpoint of improving physical properties such as tensile elastic modulus and tensile strength of the optical cable after curing.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the method for manufacturing an FRP armored optical cable according to the present invention.

The manufacturing method shown in the figure is the first step to obtain an optical fiber cable.
a second step of obtaining an armor body; a third step of twisting and covering the optical fiber cable and the armor body; and solidifying the coating layer and thermosetting resin.

and a fourth step of curing, and these steps are performed successively.

The device 10 shown in FIG. 1 is a spacer feeding device in which a spacer a1 made in advance in a separate process is wound and rotated in a horizontal plane while feeding out the spacer a1. The device is a rotary winding device that rotates the manufactured FRP armored optical cable A4 in a horizontal plane while winding it up.

First, to explain the manufacturing method of the spacer a1, as the tensile strength line a11 arranged at the center of the spacer a1, 3
．． A 5 mm fibre-reinforced thermosetting resin filament whose outer periphery was coated with 5.8 mm of low density polyethylene was used.

The details of the method for producing this tensile strength wire all are disclosed in Japanese Patent Publication No. 1-50591, which is a prior patent filed by the present applicant.

Next, molten high-density polyethylene was extruded around the outer periphery of the tensile strength wire all while rotating, and the groove width and groove depth were both 1.511!1, the outer diameter was 9°4 mm, and the number of grooves was 12. , a spiral spacer a with a spiral pitch of 500 μl
1 was produced.

In the first step, the spacer a1 is transferred to the spacer supply device 1.
0 and unwinding the spacer a1, the nylon sheathed optical fiber core wire a21 wound around the small bobbin 14
Eight tapes were fed out and inserted into the groove of the spacer a1, and a narrow polyester fiber tape a22 was wound around the outer periphery of the spacer so that the two tapes intersected.

Then, the tape A22 wrapped around it is inserted into the crosshead of the melt extruder 16, and the outer periphery is coated with low density polyethylene (manufactured by Nippon Unicar Co., Ltd., NUCG-05).
88) was extruded to form an outer sheath a23 having an outer diameter of 13.5 mm, which was immediately cooled in the cooling tank 18 to obtain an optical fiber cable a2.

In the second step, the armor body a3 is composed of 12 pieces, so
Reinforcing fibers A31 consisting of 13 glass fiber rovings (R3110 manufactured by Nittobo Co., Ltd.) and 2 glass fiber yarns (280TEX manufactured by Nippon Electric Glass Co., Ltd.) arranged on the creel stand 20 are used and are combined with unsaturated polyester resin (manufactured by Mitsui Toatsu Chemical Co., Ltd.). , Nistar H-8000) and a curing peroxide catalyst, and reinforcing fibers a3
1 was impregnated with resin, and then drawn by a molding machine 24 so that the outer diameter was 3.5 mm.

Next, the reinforcing fiber a31 is inserted into the melt extruder 26.
In an uncured state, the thermosetting resin impregnated with the thermosetting resin is extruded on the outer periphery of the thermosetting resin, and a coating layer a32 is provided so that the outer diameter becomes 4.5 fins, and then only the coating layer a32 on the surface is immediately removed. Cooled in cooling tank 28 and made 12 armor a3
I got it.

In the third step, the optical fiber cable a2 obtained in the first step is placed at the center, and the armor body a3 obtained in the second step, in which the thermosetting resin inside is in an uncured state, is passed through the guides 30 and 32. The spacer a is converged around the outer periphery of the cable a2.
Cable a rotated by a rotary take-up machine 40 that rotates in synchronization with the spacer supply device 10 in which C.1 is wound.
Twelve armor bodies a3 are arranged in close contact with each other in the circumferential direction on the outer periphery of spacer 2, and the helical pitch is the same as that of spacer a1.
They were twisted at a pitch of 0.00 mm.

Next, the twisted material in this state was passed through the crosshead of the extruder 34, and low-density polyethylene was extruded around the outer periphery of the twisted material to form an outer covering layer a41 having an outer diameter of 26.5 m+m.

In the fourth step, the outer coating layer a41 formed in the third step is first cooled and solidified in the cooling tank 36, and then
The reinforcing fibers a31 of the armor body a3 are
The thermosetting resin impregnated into the fiber is cured, thereby obtaining an FRP armored optical cable a4.
4 was wound onto the rotary winder 12 via the rotary winder 40.

The cross-sectional shape of the obtained FRP armored optical cable a4 is as follows.
As shown in the figure, the tensile performance, twisting performance, compression performance, bending performance, low temperature properties, etc. were fully satisfactory.

(Operation and Effect) According to the FRP armored optical fiber cable of the present invention, uncured FRP armored wire is closely twisted around the outer periphery of the optical fiber cable in direct connection with the production of the optical fiber cable, After applying an outer coating layer to the outer periphery, the uncured thermosetting resin inside is cured, so compared to conventional thermosetting resin compositions that take into account storage stability in the uncured stage, strength development is improved. A high thermosetting resin and catalyst can be used, and the resulting FRP armored cable can fully exhibit the armoring effect of FRP.

In addition, a first step of obtaining an optical fiber cable, a second step of obtaining an uncured FRP armored wire, the uncured armored wire is twisted to the optical fiber cable, and the outer periphery is coated with thermoplastic resin. The third step of forming the coating layer and the fourth step of curing the uncured thermosetting resin are directly connected, so compared to the case where each of these steps is performed separately, the number of separate steps is reduced. This eliminates the need for a rotary take-up machine, a rotary winder, a winding drum, etc., which are indispensable in the process, contributing to equipment reduction and labor savings.

As described above, the method of the present invention improves the physical properties of armored cables, reduces equipment costs, saves labor, and is an extremely useful method.

[Brief explanation of the drawing]

FIG. 1 is a process explanatory diagram of a method for manufacturing an FRP armored optical fiber cable according to the present invention, and FIG. 2 is a sectional view showing an example of an FRP armored optical fiber cable obtained by the same manufacturing method. al... Spacer a2... Optical fiber cable a21... Optical fiber core wire a23... Outer sheath a3... Armor body a31... Reinforcement fiber a32... ...Coating layer a4...FRP armored optical cable a41...Outer coating layer

Claims (1)

[Claims] A first step of storing an optical fiber in a groove of a spacer and forming an outer sheath around its outer periphery to obtain an optical fiber cable; and a step of impregnating reinforcing fibers with a thermosetting resin and applying heat to the reinforcing fibers. a second step in which the thermoplastic resin is coated with the curable resin in an uncured state and then solidified to obtain a plurality of uncured armor bodies, and the optical fiber cable obtained in the first step is arranged at the center; and a third step of supplying the plurality of armor bodies obtained in the second step to the outer periphery thereof, twisting them together, and then forming a covering layer with a thermoplastic resin; and the covering layer and the thermosetting resin. A method for manufacturing an FRP armored optical cable, comprising a fourth step of solidifying and hardening the resin, and the first to fourth steps are performed continuously.