JP2000266974A - Tensile strength body and spacer for optical fiber cable, and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid stress lowering at the time of 0.2% elongation. SOLUTION: This spacer 10 is provided with a tensile strength body 15 arranged in its central part, a first precoat layer 16, a second precoat layer 17 and a third precoat layer 18 provided respectively in an outer circumference of the tensile strength body 15, and a spacer main body coating 20 provided in an outer circumference of the third layer 18. The tensile strength body 15 has a fiber-reinforced synthetic resin rod 12, and a primary coating layer 14 for coating an outer circumference of the rod 12. A PBO(poly-benzbis-oxazole) fiber having a high tensile elastic modulus is used as a reinforcing fiber in the rod 12. A volume content of the PBO reinforcing fiber is made 50% or more. A cross-sectional area of the precoat layers 16, 17, 18 is made larger than that of the fiber-reinforced synthetic resin rod 12. An elastic modulus of the spacer 10 keeps 80% or more of the tensile elastic modulus inherent to the PBO reinforcing fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strength member for an optical fiber cable, a spacer, and a method of manufacturing the same, and more particularly, to a technique for improving the tensile performance of the spacer.

[0002]

2. Description of the Related Art Optical fiber cables are required to be made of non-metallic (non-metallic) cable members in order to ensure work safety or to prevent the effects of electric and magnetic fields near high-voltage power lines. It has been demanded.

[0003] If a non-metallic tensile strength member such as a fiber reinforced synthetic resin is used instead of a metal tensile strength member having a large specific gravity such as a steel wire, the whole can be reduced in weight and the cable laying length can be extended. It will be possible to save labor and reduce construction costs.

[0004] Since the tensile strength of such a non-metallic cable is required to have a high tensile property, the strength of the non-metallic cable is increased to 15.0%.
A fiber-reinforced synthetic resin rod (hereinafter sometimes referred to as FRP or PFRP) using polybenzbisoxazole (hereinafter, referred to as PBO) fibers having a tensile modulus of 00 kg / mm ² or more as reinforcement fibers is suitable.

[0005]

However, in the spacer using PFRP as the tensile strength member, the weight reduction has been greatly improved, and the workability of laying the cable has been improved. However, the tensile strength, that is, the tensile performance, is lower than that of the PBO fiber. As compared with the tensile performance calculated from the tensile modulus of the rubber composition, there was a tendency to decrease.

The reason for this is that when the outer periphery of the tensile strength member is preliminarily coated to secure the groove shape accuracy, or when the spacer body is coated to form the groove, the melt-extruded coating resin is cooled and solidified. It is considered that a compressive force acts on the tensile member in the longitudinal direction due to the heat shrinkage, and the PFRP receives a compressive stress.

That is, conventionally, even if a PFRP rod is used as a tensile strength member, the stress at the time of 0.2% elongation, which is an important specification of an optical fiber cable, is reduced, and the optical fiber cannot be effectively protected. was there.

Accordingly, the present inventors have made intensive studies to provide a spacer for an optical fiber cable using a PFRP wire as a strength member and having excellent tensile performance, and completed the present invention.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a fiber reinforced synthetic resin rod in which a reinforcing fiber made of polybenzbisoxazole fiber is impregnated with a thermosetting resin and cured. In the tensile strength member for an optical fiber cable in which a coating layer is formed, a cross-sectional area of the preliminary coating layer is larger than a cross-sectional area of the fiber-reinforced synthetic resin rod, a volume content of the reinforcing fiber is 50% or more, and
The tensile elasticity was maintained at 80% or more of the tensile elasticity inherent in the reinforcing fiber. After the fiber-reinforced synthetic resin rod is impregnated with the thermosetting resin into the reinforcing fibers and forms a primary coating layer made of a thermoplastic resin on the outer periphery thereof,
The thermosetting resin may be cured. Further, in the present invention, in a spacer for an optical fiber cable, a pre-coating layer is formed on an outer periphery of a fiber-reinforced synthetic resin rod obtained by impregnating and curing a thermosetting resin in a reinforcing fiber made of polybenzbisoxazole fiber. The outer periphery of the tensile strength member satisfying the requirements described in 1 or 2 is coated with a synthetic resin for forming a spacer main body. Further, the present invention provides a method for forming a pre-coating layer on the outer periphery of a fiber-reinforced synthetic resin rod in which a thermosetting resin is impregnated and cured with a reinforcing fiber made of polybenzbisoxazole fiber, and then forming the pre-coating layer on the outer periphery of the pre-coating layer. In a method for manufacturing a spacer for an optical fiber cable, a synthetic resin coating for forming a spacer main body portion is applied.
(Mm ² ), and when the compressive stress per unit area of the preliminary coating layer is α (kgf / mm ² ), the compressive strength acting in the longitudinal direction of the fiber reinforced synthetic resin rod determined by α × A The preliminary coating layer was formed such that a tension T of 1/4 or more of F was applied. Also,
In this method of manufacturing a spacer for an optical fiber cable, the pre-coating layer can be formed such that the tension T satisfies the relationship of T ≧ 0.5A. Further, in the method of manufacturing a spacer for an optical fiber cable according to the present invention, when applying the synthetic resin coating for forming the spacer main body portion, the molten resin is extruded while rotating a die around the preliminary coating layer. Can be.

[0010]

Embodiments of the present invention will be described below. FIG. 1 shows an embodiment of an optical fiber cable spacer using the tensile strength member according to the present invention. The optical fiber cable spacer 10 shown in FIG.
Is a tensile member 15 arranged at the center, and the tensile member 1
5, the first pre-coating layer 16, the second pre-coating layer 17, the third pre-coating layer 18, and the third pre-coating layer 1
8 and a spacer main body covering 20 provided on the outer periphery of the main body 8.

The tensile strength member 15 includes a fiber-reinforced synthetic resin rod 12 and a primary coating layer 1 covering the outer periphery of the rod 12.
And 4. The fiber reinforced synthetic resin rod 12 uses a polybenzbisoxazole (PBO) fiber having a high tensile modulus as a reinforcing fiber.

By using PBO fibers, PBO
Because the fiber has a high tensile modulus, the required fiber cross-sectional area can be reduced, and as a result, the diameter and weight of the FRP can be reduced.

Further, a thermosetting resin is used as the matrix resin for binding the reinforcing fibers, and the thermosetting resin is
Unsaturated polyester resin, vinyl ester resin is generally used, but epoxy resin, phenol resin, etc. may be used, and a catalyst such as peroxide is added to these resins,
Impregnated into PBO reinforcing fibers.

If the volume content of the PBO reinforcing fiber is less than 50%, the required performance cannot be satisfied, so it must be at least 50%. If a vinyl ester resin is used as the matrix resin, FRP
Heat resistance.

Impregnating the PBO reinforcing fiber with a thermosetting resin,
After being drawn and formed to a predetermined outer diameter, the uncured FRP coated with a molten thermoplastic resin in an annular shape and provided with a primary coating layer 14
By forming a rod and then curing the thermosetting resin inside, a tensile strength member 15 having a fiber-reinforced synthetic resin rod 12 can be obtained.

In this case, it is not always necessary to provide the primary coating layer 14 on the outer periphery of the fiber reinforced synthetic resin rod 12, and the fiber reinforced synthetic resin rod 12 without the coating layer 14 is not required.
Can be used as the tensile member 15.

In the case where the primary coating layer 14 is provided, the thermoplastic resin is applied to the preliminary coating layer 1 to be applied before the subsequent spacer body coating 20 in order to secure the shape accuracy of the spiral groove.
6, 17 and 18 having compatibility with the thermoplastic resin are selected and used, and the coating thickness is generally 0.5 to 1.5 m.
m.

If the coating thickness is less than 0.5 mm, there is a concern that the uncured resin inside may leak out through pinholes and the like,
If it exceeds 1.5 mm, there is a problem that the material is partially cured by heat at the time of forming the primary coating layer, and the physical properties of FRP are reduced.

Further, the third preliminary coating layer 18 and the spacer main body coating 20 need to be fused to each other in order to maintain strength. From this point, those having mutual compatibility are selected.

The primary coating layer 14 is preferably made of linear low-density polyethylene (LLDPE) or the like because it easily adheres to the anchor at the PFRP interface.
8. For the spacer body coating 20, a polyethylene resin such as high-density polyethylene (hereinafter referred to as HDPE) is generally recommended because of its excellent low-temperature properties.

The total cross-sectional area of the pre-coating layers 16, 17, 18 needs to be larger than the cross-sectional area of the fiber-reinforced synthetic resin rod 12. The reason is that the outer diameter of the pre-coating layer 18 is determined from the relationship of the groove depth of the spacer main body coating 20, while if the cross-sectional area of the fiber-reinforced synthetic resin rod 12 becomes large, the rigidity becomes too large. This is because the ratio of the pre-coating layer is increased as much as possible because the flexibility becomes poor and the cost increases.

The spacer main body coating 20 is formed by extruding a molten thermoplastic resin on the outer periphery of the third preliminary coating layer 18 and solidifying it by cooling. At this time, if the molten thermoplastic resin is extruded while rotating the die, a plurality of spiral grooves 22 for accommodating optical fibers can be formed on the outer periphery of the spacer body coating 20.

In the method for manufacturing a spacer for an optical fiber cable according to the present invention, the pre-coating layers 16, 17, 1
8 is A (mm ² ), and the preliminary coating layer 1
Α, (kg)
f / mm ² ), the compressive strength F acting in the longitudinal direction of the fiber-reinforced synthetic resin rod 12 determined by α × A
It is necessary to form the preliminary coating layers 16, 17, 18 so that the tension T of １ ／ or more is applied.

The reason for this is that the preliminary coating layers 16, 17, 18
Is applied to the fiber reinforced synthetic resin rod 12
If the compressive strength F acting in the longitudinal direction is less than 1/4, the tensile elastic modulus of the manufactured optical fiber cable spacer cannot maintain 80% or more of the elastic modulus inherent in the PBO fiber. is there.

Further, in the method of manufacturing a spacer for an optical fiber cable according to the present invention, the tension T is such that T ≧ T.
0.5A so as to satisfy the relation of 0.5A.
It is desirable to form 6,17,18.

When such a tension is set, the influence of heat from the pre-coating layer when forming the pre-coating layer with a crystalline thermoplastic resin such as polyethylene and the effect of shrinkage force due to cooling and solidification of the pre-coating layer are reduced. Can be eliminated.

Hereinafter, the contents of the present invention will be described with more specific examples. Specific example 1. PBO fiber (Zylon manufactured by Toyobo Co., Ltd.)
Ester resin containing peroxide-based catalysts (Mitsui Chemicals)
The product was impregnated with Estar H8100 (manufactured by Co., Ltd.) and squeezed with a squeezing nozzle so that the PBO fiber content was about 60% and the outer diameter was 4.8 mm to obtain an uncured rod.

This was introduced into a crosshead of an extruder, and a molten LLDPE resin (Nippon Unicar Co., Ltd.)
NUCG5350) is extruded at a linear velocity of 6 m / min so as to have an outer diameter of 6 mm to form a primary coating layer 14, which is then guided to a heat-curing tank and cured to form a fiber-reinforced synthetic resin rod 12. A tensile strength body 15 having the following was obtained.

Next, this primary coating layer 14 is provided.
The tensile member 15 is introduced into the crosshead of the extruder, and the resin coating is applied.
The tension per unit of the cross-sectional area is 0.51 kg /
mm ^TwoSo that the load before and after the extruder is
I took it.

Then, in a state where the high tension is applied, a molten HDPE resin (Nippon Polyolefin Co., Ltd.)
KKZ51C) to form a first pre-coating layer 16 having a thickness of 1.5 mm, and passing it through a cooling tank having a length of 1 m using water at a temperature of about 15 ° C. as a refrigerant to solidify the resin.
A 9 mm round bar was obtained.

Subsequently, a second pre-coating layer 17 of HDPE resin is again formed on the round bar under the condition that the tension is 0.51 kg / mm ² per resin-coated cross-sectional area by the same method. Was set to φ12 mm.

In this case, the sectional area A of the first preliminary coating layer 16
Is 35.34 mm ² and this first pre-coating layer 16
Is 1.18 kg / mm ² , the compressive strength F acting on the fiber reinforced synthetic resin rod 12 (= α ×
A) was 41.7 kg, and 18.2 kg was set as a tension of 1/4 or more of the compressive strength F.

The relationship between the compressive strength F and the tension T is the same when the second preliminary coating layer 17 is formed. In the case of this specific example, since the cross-sectional area of the fiber-reinforced synthetic resin rod 12 is 18.1 mm ² ,
When the second pre-coating layer 16 having a cross-sectional area of 49.48 mm ² is formed, the sum of the cross-sectional areas of the pre-coating layers becomes larger than the cross-sectional area of the rod 12.

Further, this round bar is coated with a spacer body coating 2.
0, and extruded while rotating the HDPE resin under the same tension conditions. The diameter of the rib was 17 mm, the number of grooves was 16, and the groove depth was 2.6 mm.
A 100-core induction-free (IF) spacer 10 was obtained.

When the tensile performance of the spacer 10 was measured, the stress at 0.2% elongation was 390 kg.
Since the stress value at the time of 0.2% elongation of the PBO fiber used alone as the strength member of the spacer 10 is 482 kg,
The performance retention of the IF spacer obtained by comparing the stress values was 80.9%.

The apparent tensile modulus was calculated from the stress at 0.2% elongation and found to be 10800 kg / mm ² .

Specific Example 2 68% PBO fiber content,
LL was obtained under the same conditions as in Example 1 except that the outer diameter of the fiber-reinforced synthetic resin rod 12 was changed to φ4.6 mm.
A tensile strength member 15 provided with a primary coating layer 14 having a diameter of 6 mm was made of DPE resin.

As in the first embodiment, the tension member 15 has a tension per unit sectional area of 0.51 k of the coating resin.
Under the condition of g / mm ² , the first and second preliminary coating layers 16 and 17 are sequentially formed in the order of φ9 mm and φ12 mm.
An IF spacer having a groove and a diameter of 17 mm was obtained.

When the tensile performance of this spacer was measured, the stress at the time of 0.2% elongation was 400 kg.
The tensile performance retention was calculated to be 83.0% from a comparison with the stress value of the single fiber at the time of 0.2% elongation.

The apparent tensile modulus of the spacer was calculated from this value to be 11,100 kg / mm ² .

Specific Example 3 Under the same conditions as in Example 1, P
BO fiber content 60%, fiber reinforced synthetic resin rod 1
A tensile strength member 15 having an outer diameter of φ4.8 mm and a primary coating layer 14 of φ6 mm made of LLDPE resin was prepared.

As in the first embodiment, the tension member 15 has a tension per unit sectional area of 1.181 of the coating resin.
Under the condition of kg / mm ² , the first and second preliminary coating layers 16 and 17 are sequentially formed in the order of φ9 mm and φ12 mm,
Further, a spiral coating is applied under the same tension, and
An IF spacer having a groove and a diameter of 17 mm was obtained.

When the tensile performance of this spacer was measured, the stress at the time of 0.2% elongation was 410 kg.
The tensile performance retention was calculated to be 85.1% from a comparison with the stress value of the single fiber at the time of 0.2% elongation.

The apparent tensile modulus of the spacer was calculated from this value to be 11,400 kg / mm ² .

Example 4 Under the same conditions as in Example 2, P
BO fiber content 68%, fiber reinforced synthetic resin rod 1
A tensile strength member 15 having an outer diameter of φ4.6 mm and a primary coating layer 14 of φ6 mm made of LLDPE resin was prepared.

Under the condition that the tension per unit sectional area of the coating resin is 1.18 kg / mm ² , the first and second preliminary coating layers 16 and 17 are sequentially formed on the tensile strength member 15 in the order of φ9 mm and φ12 mm. Then, spiral coating is performed with the tension of the same conditions, and I 16 grooves, φ17 mm I
An F spacer was obtained.

When the tensile performance of this spacer was measured, the stress at the time of 0.2% elongation was 440 kg.
The tensile performance retention was calculated to be 91.3% from a comparison with the stress value of the single fiber at the time of 0.2% elongation.

From this value, the apparent tensile modulus of the spacer was calculated to be 12,200 kg / mm ² .

Specific Example 5 The content ratio of the PBO fiber is 68% by volume, and the outer diameter of the fiber-reinforced synthetic resin rod 12 is φ6.4 mm.
The other conditions were the same as in Example 1, and the LLD
A tensile strength member 15 having a diameter of 8 mm to which the primary coating layer 14 of the PE resin was applied was obtained.

In the same way as in the first embodiment,
The tension per unit sectional area of the coating resin is 0.51
kg / mm ² , φ11mm, φ13.5m
The first, second, and third pre-coating layers 16, 17, and 18 are sequentially formed in the order of m and φ16 mm, and spiral coating is performed under the same conditions of tension to obtain 13 grooves and 10 mm of φ24 mm.
A 00-core type IF spacer was obtained.

In this case, the sectional area A of the first preliminary coating layer 16
Is 44.77 mm ² and the first pre-coating layer 16
Is 1.18 kg / mm ² , the compressive strength F acting on the fiber reinforced synthetic resin rod 12 (= α ×
A) was 52.83 kg, and 22.83 kg was set as a tension of 1/4 or more of the compressive strength F.

The relationship between the compressive strength F and the tension is determined by the second preliminary coating layer 17 and the third preliminary coating layer 18.
The same can be said when forming.

When the tensile performance of this spacer was measured, the stress at the time of 0.2% elongation was 850 kg.
The tensile performance retention was calculated to be 81.9% from a comparison with the stress value of the fiber alone at the time of 0.2% elongation.

The apparent tensile modulus of the spacer was calculated from this value to be 13,200 kg / mm ² .

Specific Example 6 The tension per unit area of the coating resin when the preliminary coating layer is formed by coating is 1.18 kg /
mm ^{2 under} the same conditions as in Example 5,
The outer diameter of the fiber reinforced synthetic resin rod 12 is φ6.4 mm, and a tensile strength member 15 of φ8 mm provided with the primary coating layer 14 is obtained, and the first, second, and third are successively arranged in the order of φ11 mm, φ13.5 mm, and φ16 mm. The preliminary coating layers 16, 17,
18 is formed, and a spiral coating is applied to form 13 grooves, φ.
A 24-mm, 1000-core type IF spacer was obtained.

When the tensile performance of this spacer was measured, the stress at the time of 0.2% elongation was 940 kg,
The tensile performance retention was calculated to be 90.6% from a comparison with the stress value of the fiber alone at the time of 0.2% elongation.

The apparent tensile modulus of the spacer was calculated from this value to be 14,600 kg / mm ² .

Comparative Example 1 The tension per unit area of the coating resin when coating and forming the preliminary coating layer is 0.07 kg /
It was changed to mm ² in the same conditions as in example 1, the diameter of the fiber reinforced synthetic resin rod 12 and 6mm Fai4.8Mm, the diameter of the strength members 15, 9 mm in its outer periphery, .phi.12
The first and second preliminary coating layers 16 and 17 mm were provided, and then an IF spacer having a φ17 mm spiral coating with 16 grooves was obtained.

The tensile performance of this spacer was 320 kg at a 0.2% elongation stress, and the performance retention was calculated to be 66.4% from a comparison with the tensile performance of the PBO fiber alone.

From this value, the apparent tensile modulus of the spacer was calculated to be 8,900 kg / mm ² .

Comparative Example 2 The tension per unit area of the coating resin when coating and forming the preliminary coating layer is 0.07 kg /
It was changed to mm ² in the same conditions as in example 2, the diameter of the fiber reinforced synthetic resin rod 12 and 6mm Fai4.6Mm, the diameter of the strength members 15, 9 mm in its outer periphery, .phi.12
The first and second preliminary coating layers 16 and 17 mm were provided, and then an IF spacer having a φ17 mm spiral coating with 16 grooves was obtained.

The tensile performance of this spacer was 370 kg at a 0.2% elongation stress, and the performance retention was calculated to be 76.8% from a comparison with the tensile performance of the PBO fiber alone.

When the apparent tensile modulus of the spacer was calculated from this value, it was 10300 kg / mm ² .

Comparative Example 3 The tension per unit area of the coating resin when coating and forming the preliminary coating layer is 0.07 kg /
The diameter of the fiber reinforced synthetic resin rod 12 was φ6.4 mm, the diameter of the tensile strength member 15 was φ8 mm, and the outer circumference thereof was φ11 mm, φ1 except that the diameter was changed to mm ^2.
First, second, and third pre-coating layers 16, 17, and 18 of 3.5 mm and φ16 mm are provided, and then 1 mm at φ24 mm.
An IF spacer having a spiral coating of three grooves was obtained.

The tensile performance of this spacer was 800 kg at a 0.2% elongation stress, and the performance retention was calculated to be 77.1% from a comparison with the tensile performance of the PBO fiber alone.

When the apparent tensile modulus of the spacer was calculated from this value, it was 12400 kg / mm ² .

The preliminary coating conditions of the above specific examples and comparative examples, the stress at the time of 0.2% elongation of the obtained spacers, the PBO fiber performance retention, the tensile elasticity, and the like are summarized in Table 1 below.
It is shown in FIG.

[0068]

[Table 1]

[0069]

[Table 2]

[0070]

As described above in detail in the examples and comparative examples, according to the present invention, when the outer periphery of the strength member disposed at the center of the optical fiber cable spacer is preliminarily coated, the pre-coating layer is cut off. The area is A (mm ² ), and the compressive stress per unit area of the preliminary coating layer is α (kgf / mm
² ) When と し た, 圧 縮 of the compressive strength F acting in the longitudinal direction of the fiber reinforced synthetic resin rod determined by α × A
By forming the preliminary coating layer so that the above-described tension T is applied, it is possible to suppress the compressive action in the longitudinal direction of the tensile strength member due to cooling and solidification during coating.

As a result, the lowering of the elastic modulus at the time of low elongation of the tensile strength member is eased, and a spacer for an optical fiber cable having excellent tensile performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment of an optical fiber cable spacer according to the present invention.

[Explanation of symbols]

 Reference Signs List 10 spacer for optical fiber cable 12 PFRP 14 primary coating layer 15 tensile strength member 16 first preliminary coating layer 17, 18 second and third preliminary coating layer 20 spacer main body coating 22 groove

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takayoshi Kato 2-1-1, Yabuta Nishi, Gifu City, Gifu Prefecture Inside Ube Nitto Kasei Co., Ltd. (72) Inventor Toku Ishii 2-1-1, Yabuta Nishi, Gifu City, Gifu Prefecture No. 1 Ube Nitto Kasei Co., Ltd. (72) Inventor Hideyuki Iwata 3-19-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation F-term (reference) 2H001 BB09 DD04 DD10 KK08 KK12 MM01 PP01

Claims (6)

[Claims] 1. A tensile strength member for an optical fiber cable in which a preliminary coating layer is formed on the outer periphery of a fiber-reinforced synthetic resin rod obtained by impregnating and curing a thermosetting resin in a reinforcing fiber made of polybenzbisoxazole fiber. The cross-sectional area of the coating layer is larger than the cross-sectional area of the fiber reinforced synthetic resin rod, and the volume content of the reinforcing fibers is 5%.
A tensile strength member for an optical fiber cable, wherein the tensile modulus is 0% or more and the tensile modulus is 80% or more of the tensile modulus unique to the reinforcing fiber. 2. The fiber-reinforced synthetic resin rod impregnates the reinforcing fiber with the thermosetting resin, forms a primary coating layer of a thermoplastic resin on the outer periphery thereof, and then cures the thermosetting resin. The tensile strength member for an optical fiber cable according to claim 1, wherein: 3. A spacer for an optical fiber cable, wherein the outer periphery of the tensile strength member for an optical fiber cable according to claim 1 or 2 is coated with a synthetic resin for forming a spacer body. 4. After forming a preliminary coating layer on the outer periphery of a fiber-reinforced synthetic resin rod obtained by impregnating and curing a thermosetting resin into a reinforcing fiber made of polybenzbisoxazole fiber,
In a method of manufacturing a spacer for an optical fiber cable, a cross-sectional area of the preliminary coating layer is set to A (mm ² ), wherein a synthetic resin coating for forming a spacer main body portion is applied to an outer periphery of the preliminary coating layer. The compressive stress per unit area of the coating layer is α (kgf / m
m ² ), the compressive strength F acting in the longitudinal direction of the fiber reinforced synthetic resin rod determined by α × A is 1 /
A method for manufacturing a spacer for an optical fiber cable, wherein the preliminary coating layer is formed so that four or more tensions T are applied. 5. The method for manufacturing an optical fiber cable spacer according to claim 4, wherein the pre-coating layer is formed such that the tension T satisfies the relationship of T ≧ 0.5A. Of manufacturing optical fiber cable spacers. 6. The molten resin is extruded while rotating a die around the outer periphery of the preliminary coating layer when applying the synthetic resin coating for forming the spacer body. Manufacturing method of an optical fiber cable spacer.