JPS61149910A - Production of spacer for carrying optical fiber - Google Patents

Abstract

PURPOSE:To uniform the shape of a spacer body by coating a tensile strength wire or coated tensile strength wire with thermoplastic resin after setting the ratio of its apparent external diameter and the apparent external diameter of the groove part of the spacer body within a specific range. CONSTITUTION:A tension member 2 is composed of the tensile strength wire or coated tensile strength wire formed by coating the tensile strength wire with thermoplastic resin, the ratio of its apparent external diameter d0 and the apparent external diameter d3 of the groove part of the spacer body 9 is so set that 0.5<d0<0.98, and then the external periphery of this tension member 2 is coated with thermoplastic resin to form the spacer body 9. The apparent external diameter d0 of the tension member 2 is substituted with the apparent external diameter d1 of the tensile strength wire when the tensile strength wire itself is coated with the spacer body directly or with the external diameter d2 after coating when the coated tensile strength wire is used. Thus, the width, depth, etc., of the groove part of the spacer are uniformed in a sectional direction and a lengthwise direction.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is used as an element of an optical fiber cable,
The present invention relates to a method of manufacturing a spacer that protects and supports a plurality of optical fibers.

(Prior Art and Its Disadvantages) As is well known, when installing optical fibers for telecommunications, spacers are used that are made of thermoplastic resin and have various groove shapes formed in the longitudinal direction around the outer periphery of the tensile strength wire. The optical fibers are held and aggregated in each groove. Therefore, the precision of the fM shape of the spacer affects the transmission characteristics of the optical fiber, and strict precision is required.

By the way, as a manufacturing method for this type of spacer, the outer periphery of the tensile strength wire is coated with thermoplastic resin by rotating a die with various mouth shapes or by melting and extruding it from a fixed die, and the spacer is made by cooling and solidifying the outer periphery of the tensile strength wire. is manufactured.

Here, a spiral groove is formed in the spacer body in the longitudinal direction of the groove shape using a die.

The tensile strength wire diameter of the optical fiber spacer manufactured by such a method, and the outer diameter of the glue part of the spacer body.

The diameter of the grooves and their number are determined by the specifications of the spacer required when aggregating optical fibers, and various tensile strength wires and spacer body sizes and shapes are used.

However, the above-described manufacturing method had the following drawbacks.

In other words, the ratio (d+/di) of the tensile strength wire diameter d determined for the required tensile strength as a spacer for supporting an optical fiber and the groove diameter d3 of the spacer main body.
If the outer periphery of the tensile strength line is extruded and coated with thermoplastic resin in one step to form the spacer body, the groove shape of the spacer body may become uneven or the spacer body may be significantly deformed. It was difficult to obtain the desired dimensions, shape, and precision, and even if they were obtained, the yield was extremely poor (see FIG. 3A).

Moreover, the above-mentioned tendency was remarkable when crystalline resins such as various polyethylenes and polypropylenes were used as thermoplastic resins.

The reason for this is that when the crystalline thermoplastic resin is extruded from a die and cooled and solidified, it rapidly shrinks in volume due to crystallization, but the start of this shrinkage is different between the spacer groove and the inner periphery of the groove. As a result, it is thought that the inner circumferential portion of the groove, where the cooling rate is slow and takes the longest time to shrink, undergoes considerable cooling and solidification, or solidifies in a shape that draws in the groove.

Furthermore, in the above-mentioned method, when the die is rotated to form a spiral groove, the state of stress is different from that when forming a straight line, making it difficult to form a uniform groove.

(Object of the Invention) The present invention has been made in view of the above-mentioned conventional drawbacks, and its purpose is to arrange a tensile strength wire in the center and form a spacer body from thermoplastic resin on the outer periphery of the tensile strength wire. An object of the present invention is to provide a new manufacturing method for making the width, depth, etc. of the groove portion of an optical fiber supporting spacer made uniform over the cross-sectional direction and the longitudinal direction.

(Structure of the Invention) In order to achieve the above object, the present invention has a spacer body formed of a crystalline thermoplastic resin, which has a tensile strength line in the center and a groove extending in the longitudinal direction on the outer periphery of the tensile strength line. In the method for manufacturing a spacer for an optical fiber carrier, a tension member made of the tensile strength wire or a coated tensile strength wire obtained by coating the tensile strength wire with a thermoplastic resin is set to have an assumed outer diameter dO, and an assumed outer diameter d3 of the groove portion of the spacer body.
After setting the ratio to satisfy the relational expression of 0.5<do/d3<0.98, the outer periphery of the tension member is coated with the crystalline thermoplastic resin to form the spacer body. Characterized by Shiruko.

In addition, here, the assumed outer diameter do of the tension member is, when the tensile strength wire itself is directly coated with the spacer body,
The assumed outer diameter d of the tensile strength wire is replaced by the coated outer diameter d2 when a coated tensile strength wire coated with a thermoplastic resin is used, but when the tensile strength wire is a twisted steel wire, The assumed outer diameter d1 is the envelope diameter of the outer periphery of a plurality of twisted steel wires, and the uncircumcised outer diameter d3 of the grooves of the spacer body is the diameter of the circle inscribed in all the grooves. This is the target value for the spacer body.

To explain the above configuration in more detail, as the tensile strength wire, a monotonic wire, a twisted steel wire 2 reinforced plastic wire, a twisted wire thereof, etc. are used.

In addition, as the coating resin for the above-mentioned coated tensile strength wire, various modified polyethylenes and copolymers such as linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), and adhesive polyethylene, and polypropylene homopolymers and copolymers are used. etc., and the spacer body forming resin may be the same as the above resin, and
has high mutual compatibility with the coating resin of the coated tensile strength wire;
It may be possible to use an R bonding stand.

(Function of the invention) In the manufacturing method of the present invention having the above configuration, the outer diameter dO of the tension member made of the tensile strength wire itself or the coated tensile strength wire, and the assumed outer diameter d3 of the groove of the spacer body.
The ratio (do/d3) is greater than 0.5 and 0.98
Because it is set smaller than There is almost no delay in speed, the inner peripheral portion of the groove is prevented from pulling in the rib, and as a result, the groove of the spacer body is prevented from being deformed, and a spacer having desired dimensions and shape and accuracy can be obtained.

In addition, when using a coated tensile strength wire, if the coating resin of the coated tensile strength wire and the resin for forming the main body are highly compatible with each other, they will fuse together when they come into contact with each other. However, both resins can be joined while being fused, and in addition to the above-mentioned effects, the influence of the uneven twisted structure of the tensile strength wires is eliminated, especially compared to the case where the spacer body is directly formed on the outer periphery of the tensile strength wires with a twisted structure. This results in more stable dimensions and improved precision.

The above-mentioned outer diameter ratio (do/d3) was confirmed and set by the inventors' experiments as described later, and if do/(f3 is smaller than 0.5, the inner diameter of the spacer groove The above effect cannot be obtained because the peripheral part becomes thick, and on the other hand, d
If o/d3 is larger than 0.98, the inner peripheral part of the groove will become too thin, causing problems with the uprightness and strength of the rib part, and when the tension member passes through the die part, it will not fit into the through hole of the nozzle. Problems such as friction and uneven take-up tension also occur.

Therefore, when the outer diameter ratio (do/dz) is near the lower limit of the above range, either the tensile strength wire itself or a coating on it can be used as the tension member, but near the upper limit, the tensile strength of the coating on the tensile strength wire Preferably, a line is used.

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

FIG. 1 is an explanatory view of a type of device A used in carrying out the present invention, in which a tension member 2 wound around a bobbin 1 is placed in a targeted cross section of a spacer body 9 shown in FIG. A cross rad die 3 with a nozzle 4 corresponding to the shape
While rotating the nozzle 4, the outer periphery of the tension member 2 is extruded and coated with molten crystalline thermoplastic resin, and then introduced into a cooling tank 5 using a refrigerant such as air or water to cool and solidify. Wind it around the winding bobbin 6,
As shown in FIG. 2, a spacer body 9 is formed on the outer periphery of the tension member 2, having a plurality of spiral grooves 7 extending in the longitudinal direction and ribs 8 separating the grooves. Here, the tension member 2 is a single wire or a twisted wire tensile strength wire 2a.
Resin coating layer 2b on itself or on these tensile strength wires 2a
When forming the resin coating layer 2b, another die is provided between the bobbin 1 and the cross-layer die 3 to form the resin coating layer 2b and the spacer body 9. may be performed continuously.

What should be noted here is that when using the tensile strength wire 2a as it is as the tension member 2, the outer diameter dl s of the tension member 2
When using a coated tensile strength wire formed with
and the target outer diameter d3 of the groove portion 7 of the spacer body 9 (d+/dz or dz/dz, collectively referred to as d0/d3) is 0.5<do/d.
The purpose is to set the outer diameter dO of the tension member 2 so as to satisfy the relational expression z<0.98.

・Example 1 Twisted steel wire (apparent outer diameter d+ = 1.2 mm) made by twisting nine steel wires with a diameter of 0.38 mm (three in the center and six on the outside) as a tensile strength wire. ), and after degreasing with acetone, insert the cloth into a rad die to form a resin coating layer 2b with LLDPE (M I = 1.0), and after cooling and solidifying, the coating outer diameter d2 is 2.8 m.
A coated tensile strength wire of m was obtained.

Then, HDPE (Mr
= 0.2), six grooves 8 are arranged at equal intervals, - the target value of the outer diameter d4 is 5.7IIIFa, the target value of the outer diameter d3 of the groove part 7 is 3n++a, and the helical pitch is 150.
The spacer body 9 was formed in the following manner.

As a result, the peak diameter of the rib 8 was 5.5 to 5.65 mm, and the valley diameter of the groove 7 was 2.8 to 2.9 mm.

The apparent outer diameter ratio dz/d3 between the spacer body 9 and the coated tensile strength wire 2 is 0.93, and the variation in groove width between the inner and outer circumferences and the variation in groove depth are about 0.1. Compared with Comparative Example 1 having almost the same configuration, the variation was smaller and the cross-sectional shape was not deformed, giving good results.

22 The same as in Example 1 was used as the tension member 2, 1-IDPE was used for the resin coating layer 2b, and the outer diameter d2 was set to 2.0+em.

The spacer body 9 is made of HDPE, the target value of the diameter d4 of the rib 8 is 5.6ia+m, the target value of the outer diameter d3 of the groove 7 is 3 mm, and the helical pitch is 155III.
Ill.

As a result, the peak diameter of the rib 8 was 5.8 to 5.9 mm, and the valley diameter of the groove 7 was 3.0 to 3.1 ml1.

In this case, the outer diameter ratio d2/(13 was 0.67, and although the variation in groove width etc. was larger than in Example 1, results were obtained that did not cause any practical problems.

Comparative Example 1 The same twisted steel wire as in Example 1 was used as the tension member 2, and after degreasing it, the spacer body 9 was formed directly on it with HDPE.

The target dimensions of the spacer body 9 are that the outer diameter d4 of the rib 8 is 5.
7111. The outer diameter d3 of the groove portion 8 was 3.0 mm, and the helical pitch was 150111.

As a result, the diameter of the rib 8 was 5.5 to 5.71111. The groove diameter of the groove 7 was 2.9 to 3.3 ia+.

In this case, the outer diameter ratio (L/d3 is 0.4,
The outer circumferential groove width varied widely from 0.9 to 1.51I11, and in particular, the groove depth could not be measured due to deformation.

As double i1 etension member 2, outer diameter 0.6IllI11
(1+6) twisted steel wires (apparent outer diameter d+ =
1.81), and a resin coating JI2b was formed on its outer periphery with HDPE so that the outer diameter d2 was 41111R.

The spacer main body 9 is made of l-IDP E, and its target outer diameter d4 is set to about 9.5 mm so that five ribs 8 are formed at equal intervals. Omn+, the target outer diameter of the groove 7 is 4.2111. The spiral pitch was set to 4001.

As a result, the diameter of the rib 8 is 8.1 to 8.811J.
The valley diameter is 4.15 to 4.25111, and the outer diameter ratio d
2/d3 is approximately 0.95, and the groove width and groove depth are 2.0~
There was little variation within the range of 2.2, and almost no shape deformation was observed.

・Comparative example 2 The apparent outer diameter d of the tension member 2.

The spacer body 9 uses twisted steel wire with a length of 1.811 m.
HDPE is used, and the target outer diameter d4 of the rib 8 is 9.0 mm.
+, the target outer diameter d3 of the groove portion 7 was set to be 4.51, the number of grooves was 5, and the spiral groove was set to have a pitch of 400 cm.

As a result, the diameter of the rib 8 is 8.7 to 9.0 mm, and the groove 7 is
It was impossible to measure the target outer diameter.

The outer diameter ratio d+/d3 was 0.4, and large variations in groove dimensions and large deformations in shape were observed.

・Example 4 As the tension member 2, the apparent outer diameter d of (1+6) pieces of steel wire with an outer diameter of 1.6 ml is 4.8e+Il
The twisted steel wire was used as is.

The forming resin of the spacer body 9 is HDPE, and the target external dimensions are as follows: The outer diameter d4 of the beam 8 is 10 m1, and the outer diameter dz of the groove 7 is 6i.
The number of n+1 threads was 6, and the helical pitch was set to 300 mm.

As a result, the peak diameter of the rib 8 was 9.8 to 10 mm, and the valley diameter of the groove 7 was 5.8 to 6.1 mm.

In this case, the outer diameter ratio d+/d3 was 0.8, but a groove with little variation in dimension and shape deformation was obtained.

- Example 5 As the tension member 2, a monotonic wire with an outer diameter d of 2 mm was directly used.

The forming resin of the spacer body 9 is HDPE, the target outer diameter d4 of the rib 8 is 6.0 mm, and the target outer diameter d3 of the groove portion 7 is 2.81 mm.
111. The number of threads was 4 and the helical pitch was set to 200 mm.

In this example, the outer diameter ratio d+/d3 is 0.71, and the diameter of the rib 8 is 5.96 to 6.07 mm, 1ll.
The diameter of the valley of the s portion 7 was 2.76 to 2.88 mm, and good results were obtained in the dimensional accuracy and shape of the groove as in the above embodiment.

・Example 6 The tension member 2 has an apparent outer diameter d1 of 3,
A glass fiber reinforced synthetic resin (GFRP) of 5n+g+ was used, and a resin coating layer 2b of LLDPE was formed on its outer periphery, so that the outer diameter d2 was 5.5 mm.

The forming resin of the spacer body 9 is HDPE, the target outer diameter d4 of the rib 8 is 9.5flll, and the target outer diameter d3 of the groove portion 7 is 7n.
v, the number of threads was 12, and the helical pitch was set to 30 (hnn).

In this case, the outer diameter ratio dz/dx is 0.19, but
The diameter of the formed groove 8 is 9.69 to 9.75 nv,
The root diameter of the groove portion 7 was 6.68 to 6.73 mm, and a groove with little variation in dimension and shape deformation was obtained.

・Example 7 As the tension member 2, the apparent outer diameter is d+2
．． Glass fiber reinforced synthetic resin (GFRP) of 0111111
), and a resin-covered N layer 2b was formed on the outer periphery of a mixture of LLDPE and HDPE, so that the outer diameter d2 was 4.0 IIl.

The forming resin of the spacer body 9 is HDPE, the target outer diameter d4 of the rib 8 is 9.5 mm, and the target outer diameter d3 of the groove portion 7 is y, om.
m, the number of threads was 12, and the helical pitch was set to 250 mm.

As a result, the formed rib 8 has a mountain diameter of 9.13 to 9.13.
The valley diameter of 83III111 groove part 7 is 6.68 to 7.05 m.
It was m.

In this case, the outer diameter ratio d+/d3 is 0.51, but
A groove with little variation in dimension and shape deformation was obtained.

- Comparative Example 3 The tension member 2 has an apparent outer diameter d1 of 2.
Using 0mn+ glass fiber reinforced synthetic resin (GFRP), forming a resin coating layer 2b of LLDPE on its outer periphery,
The outer diameter d2 was set to 3.0 mm.

The forming resin of the spacer body 9 is 1-IDPE, the target outer diameter d4 of the rib 8 is 9.5n+11+, and the target outer diameter d3 of the groove portion 7.
is about 7. Omm, the number of threads is 12 and the spiral pitch is 3.
It was set to 00mm.

In this case, the outer diameter ratio d+/dx was 0.43, the peak diameter of the formed rib 8 was 9.65 to 9.85 mm, and the valley diameter of the groove 7 was 7.13 to 7.28 mm. However, satisfactory results were not obtained in terms of the variation in groove dimensions and the shape of the grooves.

2111L Tension member 2 has an apparent outer diameter d1 of 2.
Omn+ glass fiber reinforced synthetic resin (GFRP) is used, a HOPE resin coating layer 2b is formed on the outer periphery, and the outer diameter d2 is 3. It was set to Omm.

The resin used to form the spacer body 9 is IDPE, the target outer diameter d4 of the rib 8 is 13a+m, and the target outer diameter d3 of the groove 7 is 6.5.
mm, the number of threads was 6, and the helical pitch was set to 330 mm.

In this case, the outer diameter ratio IL/dx was 0.46, the peak diameter of the groove 8 was 13.0 to 13.4 mm, and the valley diameter of the groove 7 was 6.5 to 13.4. Satisfactory results were not obtained regarding either the variation in groove dimensions or the shape of the grooves.

The following table summarizes Examples 1 to 7 and Comparative Examples 1 to 4.

As is clear from the table, the ratio do/di between the outer diameter (d+ or dz) of the tension member 2 and the target outer diameter d3 of the groove 7 of the spacer body 9 is set within the range of 0.5 to 0.98. When the spacer main body 9 is manufactured after setting, the dimensional accuracy of the grooves has little variation, the shape is stable with almost no deformation, and a desired spacer suitable for supporting an optical fiber can be manufactured.

Note that FIG. 3A is an enlarged cross-sectional view of the spacer manufactured in Comparative Example 2, about 10 times larger, and the groove portion 7 was greatly deformed.

Further, FIG. 3B is an approximately 10 times enlarged cross-sectional view of the spacer manufactured in Example 3, in which almost no deformation of the groove portion 7 was observed. Further, in the above embodiments, spacers each having a spiral groove are illustrated, but it goes without saying that the present invention can also be applied to a straight groove, and the same effects can be obtained.

(Effects of the Invention) As described above in detail in the Examples, according to the method for manufacturing an optical fiber supporting spacer according to the present invention, the speed of shrinkage that occurs when the resin forming the spacer body is cooled and solidified is partially reduced. A spacer with excellent dimensional accuracy can be obtained by eliminating the difference and the influence of stress when forming a spiral groove.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the method for manufacturing an optical fiber supporting spacer according to the present invention, and FIG. 2 is a cross-sectional view (A in the same figure) and a perspective view (B ). FIG. 3(A) is an enlarged sectional view of a spacer manufactured by the conventional method, and FIG. 3(B) is an enlarged sectional view of a spacer manufactured by the method of the present invention. 1...Bobbin 2...Tension member 3...Rado die to cross 4...Nozzle 5...
Cooling tank 6... Winding bobbin 7... Spiral groove 8... Rib 9... Spacer body Patent applicant Ube Nizuka Kasei Co., Ltd. Representative Patent attorney - Kensuke Iro Figure 1 Figure 2, Figure 3

Claims (2)

[Claims] (1) In a method for manufacturing an optical fiber supporting spacer, the spacer body is formed of a crystalline thermoplastic resin and has a tensile strength line in the center and a groove extending in the longitudinal direction on the outer periphery of the tensile strength line. Alternatively, the tension member is made of a coated tensile strength wire obtained by coating the tensile strength wire with a thermoplastic resin, and the ratio of its assumed outer diameter d_0 to the assumed outer diameter d_3 of the groove of the spacer body is 0.5<d_0/d_
A spacer for supporting an optical fiber, characterized in that the outer periphery of the tension member is coated with the crystalline thermoplastic resin to form the spacer body after the relational expression 3<0.98 is satisfied. manufacturing method. (2) The light according to claim 1, wherein the coating resin of the coated tensile strength wire and the thermoplastic resin used for the spacer body are made of synthetic resins that have high compatibility with each other and fuse together. A method for manufacturing a spacer for supporting fibers.