5 TECHNICAL FIELD
[OOO 1 ]
The present invention relates to a manufacturing method of an optical fiber
ribbon, in which a plurality of optical fibers coated with a resin are arranged in parallel
to one another, and these respective optical fibers are fixed to one another
10 intermittently along a longitudinal direction thereof.
BACKGROUND ART
[0002]
An optical fiber ribbon for use in an optical fiber cable is one, in which an
15 optical fiber strand or an optical fiber core wire is formed by coating outer
circumferences of optical fiber bare wires (glass fibers) with a resin, a plurality of the
optical fiber strands or the like are arranged in parallel to one another, and these are
coated with a collective coating layer to be thereby formed into a ribbon shape. In
such a way, work of connecting the plurality of optical fibers (optical fiber strands or
20 the like) to one another collectively by fusion or connectors can be optimized.
[0003]
With regard to the optical fiber ribbon formed by such collective coating as
described above, a packaging density thereof is lowered by an amount of such a
ribbon-like collective coating resin, and in addition, a bending direction thereof is
25 regulated in terms of design of the optical fiber cable. Therefore, in particular, in an
optical fiber cable with a relatively small number of core wires (approximately several
ten core wires to hundred core wires), for which requests for a density increase and a
diameter reduction are increased, the optical fiber ribbon is disadvantage in
comparison with an ultimate packaging form with regard to such a density increase and
30 a diameter reduction as in a simple aggregate of single core wires.
[0004]
Therefore, for example, in an optical fiber ribbon described in the following
PTL 1, a plurality of optical fibers arranged in parallel to one another are fixed to one
another intermittently (partially) along a longitudinal direction thereof, whereby the
fact that the packaging density is lowered and that the bending direction is regulated is
5 suppressed.
[OOOS]
Manufacturing of the optical fiber ribbon in which the optical fibers are fixed
intermittently to one another is carried out in such a manner that a plurality of optical
fibers, which include resin coating layers and are arranged in parallel to one another,
10 are sent out from optical fiber insertion holes open on an outlet surface of a coating
dice. In this event, dam members such as shutters and discs are moved between the
optical fiber insertion holes adjacent to one another, whereby ejection and damming of
the resin for use in such intermittent fixation are carried out alternately.
15 CITATION LIST
PATENT LITERATURE
[0006]
PTL I :Japanese Patent Laid-Open Publication No. 20 10-3301 0
20 SUMMARY OF INVENTION
[0007]
However, in this case, there is an apprehension that, in the event of being sent
out from the optical insertion holes, the optical fibers may be rubbed by outlet portions
of the coating dice, and the resin coating on the optical fiber bare wires may be shaved
25 off.
[0008]
In this connection, it is an object of the present invention to suppress the
coating resin from being shaved off in the event where the optical fibers are sent out
from the coating dice.
30 [0009]
An invention of claim 1 is a manufacturing method of an optical fiber ribbon,
in which a plurality of optical fibers coated with a resin are arranged in parallel to one
another, and these respective optical fibers are fixed to one another intermittently along
a longitudinal direction thereof, the manufacturing method including: arranging, in
parallel to one another, a plurality of optical fibers in which a Young's modulus of the
5 coating resin on outermost layers is 300 MPa or more; and connecting these respective
optical fibers to one another intermittently along the longitudinal direction.
[OO 1 01
An invention of claim 2 is the manufacturing method of an optical fiber ribbon
according to claim 1, characterized in that, when the Young's modulus of the coating
10 resin on the outermost layers is 300 MPa or more to less than 600 MPa, a plurality of
Q optical fibers in which friction force of the coating resin on the outermost layers is 0.3
N or less are arranged in parallel to one another, and the respective optical fibers are
connected to one another intermittently along the longitudinal direction.
[OOll]
15 An optical fiber ribbon of an invention of claim 3 is characterized in being
manufactured by the manufacturing method of an optical fiber ribbon according to
either one of claims 1 and 2.
[OO 121
In accordance with the present invention, slippage of the coating resin in the
20 optical fibers is enhanced in consideration of the Young's modulus of the resin, and
accordingly, the coating resin can be suppressed from being shaved off in the event
where the optical fibers are sent out from the coating dice.
BRIEF DESCRIPTION OF DRAWINGS
25 [0013]
[FIG. I]
FIG. 1 is a planar perspective view of an optical fiber ribbon, showing an
embodiment of the present invention.
[FIG. 21
3 0 FIG. 2 is an enlarged cross-sectional view taken along a line A-A of FIG. 1.
[FIG. 31
FIGS. 3(a) to 3(d) are explanatory views showing a measurement method of
friction force of an optical fiber sequentially from FIG. 3(a) to FIG. 3(d).
FIG. 4 is a perspective view showing a manufacturing apparatus of the optical
fiber ribbon of FIG. 1.
5
DESCRIPTlON OF EMBODIMENTS
[00 1 41
A description is made of an embodiment of the present invention based on the
drawings.
10 [0015]
As shown in FIG. 1, an optical fiber ribbon (hereinafter, referred to as a
ribbon) 1 of an optical fiber cable according to the embodiment of the present
invention is configured in such a manner that a plurality of optical fibers 3 are arranged
in parallel to one another, and here, is composed of the optical fibers 3 of which
15 number is N in total. Among the N pieces of the optical fibers 3, two optical fibers 3
adjacent to each other are fixed to each other intermittently along a longitudinal
direction of the optical fibers 3 concerned by adhered portions 5, each of which serves
as a fixing portion for a plurality of spots. Portions between the adhered portions 5
provided in plural along the longitudinal direction are formed as separated portions 7
20 in which the optical fibers 3 are not adhered to each other.
[00 1 61
In this event, adhered portions 51-2 between No. 1 and No. 2 of the optical
fibers 3 and adhered portions 52-3 between No. 2 and No. 3 of the optical fibers 3 are
located at positions shifted from each other so as to be alternate with each other along
25 the longitudinal direction of the optical fibers 3. In a similar way, adhered portions
5(N-2)-(N-1) between No. N-2 and No. N-l of the optical fibers 3 and adhered
portions 5(N-1)-N between No. N-I and No. N of the optical fibers 3 are located at
positions shifted from each other so as to be alternate with each other along the
longitudinal direction of the optical fibers 3. As described above, with regard to the
30 adhered portions 5 of the mutual two optical fibers 3, those adjacent to each other in a
direction where the optical fibers 3 are arranged in parallel to each other are located at
,
5
the positions shifted from each other so as to be alternate with each other along the
longitudinal direction of the optical fibers 3.
[OOI 71
FIG. 2 is a cross-sectional view taken along a line A-A of FIG. I, in which
5 each of the optical fibers 3 is an optical fiber strand composed of: a quartz glass fiber
9; a soft resin 1 1 that coats an outer circumference of the glass fiber 9; and an
ultraviolet curable resin 13 that further coats an outer circumference of the soft resin 1 1
Then, the mutual two optical fibers 3 are connected and fixed to each other by the each
of above-described adhered portions 5 formed on both front and back sides thereof.
10 Here, the ultraviolet curable resin 13 described above is a resin of outermost layers in a e state before the optical fibers 3 adjacent to each other are fixed to each other
intermittently by the adhered portions 5. Note that, in place of the optical fiber
strands described above, the optical fibers 3 may be optical fiber core wires in which
outer circumferences of the optical fiber strands are coated with a resin such as colored
15 ink. In this case, the resin such as the colored ink serves as the resin of the outermost
layers of the optical fiber core wires in the state before the optical fibers 3 are fixed to
each other intermittently by the adhered portions 5.
[OOI 81
For manufacture of the ribbon 1 in which the optical fibers 3 are thus fixed
20 intermittently, a ribbon manufacturing apparatus including a coating dice 17 (FIG. 4) to
be described later is used.
100 I 91
Here, in this embodiment, slippage of the ultraviolet curable resins 13 is
enhanced in order to suppress the ultraviolet curable resins 13 from being rubbed and
25 shaved off at an outlet portion of a coating dice 17 in the event where the optical fibers
3 are sent out from the coating dice 17 concerned at the time of manufacturing the
ribbon 1 by the ribbon manufacturing apparatus described above.
[0020]
Specifically, with regard to each of the ultraviolet curable resins 13 of the
30 optical fibers 3 here, the fact that a Young's modulus thereof is 300 MPa or more is an
essential requirement, and in addition. when the Young's modulus is 300 MPa or more
to less than 600 MPa, friction force measured by the following measurement method is
set at 0.3 N or less.
[002 1 ]
A description is made below of a measurement method of the friction force.
5 First, as shown in FIG. 3(a), a single ring 30a with a diameter of 7 cm is formed of a
predetermined-length optical fiber specimen 30 for evaluation, which is used for each
of the optical fibers 3, and an end portion 30b on one end side of this optical fiber
specimen 30 is inserted into the ring 30a so as to make a knot. As shown in FIG. 3(c),
this insertion work is performed one more time, that is, is repeated twice, and a contact
10 portion 30d as shown in FIG. 3(d), in which portions of the ultraviolet curable resin 13
are brought into contact with each other, is formed.
[0022]
Then, in a state of FIG. 3(d) described above, the end portion 30b on one end
side with respect to the ring 30a of the optical fiber specimen 30 and an end portion
15 30c on other end side with respect thereto are individually grasped by a tensile testing
machine (not shown), and are pulled in a direction (up-and-down direction in FIG.
3(d)) of being spaced apart from each other so that the diameter of the ring 30a can be
reduced. At this time, a pulling speed is set at 5 mmlmin, and a pulling time is set at
2 minutes, and an average load value (surface friction force) of force at the time of this
20 pulling is set at the friction force of the ultraviolet curable resin 13.
[0023]
Table 1 shows relationships between the friction force (N) and the Young's
0 modulus (MPa). Here, the ribbon 1 is manufactured by the ribbon manufacturing
apparatus to be described later, and the case where a shaved chip of the ultraviolet
25 curable resin 13 on the outermost layer is generated on the outlet portion of the coating
dice 17 is denoted by "x", and the case where the shaved chip concerned is not
generated thereon is denoted by "on.
[Table I]
Young's modulus (MPa)
[0024]
Note that, in the ribbon manufacturing apparatus at this time, a feeding speed
of the optical fiber 3 is set at 120 mlmin, the number of revolutions of each disc 27 as a
dam member is set at 400 rpm, a length L of each adhered portion 5 is set at 100 mm,
5 and a length M of each separated portion 7 is set at 200 mm, whereby a length of a
pitch between the adhered portions 5 is set at 300 mm.
[0025]
In accordance with Table 1, from a viewpoint of the Young's modulus of the
ultraviolet curable resin 13, there are cases of "0" when the Young's modulus is 300
10 MPa or more, and there are not cases "0" when the Young's modulus is less than 300
MPa. Hence, it is essential that the Young's modulus be at least 300 MPa or more.
Meanwhile, from a viewpoint of the friction force, in the case where the friction force
exceeds 0.3 N under such a condition where the Young's modulus is 300 MPa or more,
there are cases of "x" when the Young's modulus falls down below 600 MPa, and there
15 are not cases "x" when the friction force is 0.3 N or less. Therefore, in the case
0 where the Young's modulus is 300 MPa or more to less than 600 MPa, it is necessary
that the friction force be 0.3 N or less.
[0026]
Based on the above, in order to realize the case where the shaved chip of the
20 ultraviolet curable resin 13 on the outermost layer is not generated on the outlet portion
of the coating dice 17, that is, in order to make it possible to suppress the coating resin
from being shaved off at the outlet portion of the coating dice 17 in the event where
each optical fiber 3 is sent out from the coating dice 17 concerned, the following
400
o
0
o
x
Friction
force
(N)
-
150
x
X
x
x
0.05
0.1
0.2
0.3
.
0.4
0.5
500
o
0
o
x
x
200
x
X
x
x
600
o
0
o
o
o
300
o
0
o
x
x
800
o
0
o
o
1500
o
0
o
o
conditions become necessary.
[0027]
With regard to the ultraviolet curable resin 13, it is essential that the Young's
modulus thereof be at least 300 MPa or more, and in addition, when the Young's
5 modulus is 300 MPa or more to less than 600 MPa, the friction force measured by the
measurement method described above is 0.3 N or less.
[0028]
In general, an ultraviolet curable resin for use in the ultraviolet curable resins
13 contains, as basic constituent components, a radical polymerizable oligomer
10 containing an unsaturated group (for example, an acryloyl group), a reactive monomer
as a reactive diluent, and a polymerization initiator. Moreover, to the ultraviolet
curable resin concerned, required amounts of a variety of additives and the like are
blended, the additives including a pigment, an ultraviolet absorber, a light stabilizer, a
polymerization inhibitor, a silane coupling agent, a leveling agent, a lubricant, an
15 oxidation stabilizer, an antioxidant, a storage stabilizer and the like.
[0029]
Moreover, in the ultraviolet curable resin, mainly, a type, structure and
molecular weight of the radical polymerizable oligomer, and types of the reactive
monomer, the polymerization initiator and the variety of additives are selected, and
20 further, a compounding ratio of the radical polymerizable oligomer, the reactive
monomer, the polymerization initiator and the variety of additives is adjusted, whereby
it is possible to adjust a variety of characteristics.
[0030]
The ultraviolet curable resin as described above is used for the ultraviolet
25 curable resin 13, whereby, also with regard to a Young's modulus and friction force of
the resin on the outermost layer of each optical fiber 3 after the resin concerned is
cured, those with desired characteristics adapted to this embodiment can be obtained.
[003 1 ]
Next, a description is made of the ribbon manufacturing apparatus that
30 manufactures the ribbon 1 described above. This ribbon manufacturing apparatus
includes the above-described coating dice 1 7, which performs a fiber array inglresin
supplying process for arraying the plurality of optical fibers 3 as shown in FIG. 4 and
supplying the above-described ultraviolet curable resin that is uncured.
[0032]
Moreover, in front of the coating dice 17 in a feeding direction of the optical
5 fibers 3, the ribbon manufacturing apparatus includes: for example, two ultraviolet spot
lamps 19 as resin curing energy irradiation devices which perform a resin curing
process for curing the uncured ultraviolet curable resin by energy irradiation; and a line
concentrating roll 21 that concentrates the plurality of optical fibers 3 sent out from the
coating dice 17. Moreover, below the coating dice 17, resin removing means 23 and
10 brush cleaning means 25 are installed.
9 [0033]
The coating dice 17 includes, in an inside thereof, a resin reservoir (not
shown) that reserves the uncured ultraviolet curable resin. On an outlet surface 17a
of the coating dice 17, a plurality of optical fiber insertion holes 17b, which
15 communicate with the resin reservoir, are opened. From the plurality of optical fiber
insertion holes 17b, the plurality of optical fibers 3, which have passed through the
resin reservoir, are arrayed and sent out. Moreover, the optical fiber insertion holes
17b adjacent to one another communicate with one another through narrow
communication holes (not shown).
20 [0034]
With such a configuration, at the time of being sent out from the respective
optical fiber insertion holes 17b, the plurality of optical fibers 3 are cured after the
uncured ultraviolet resin is coated on surfaces of the outer circumferences of the
ultraviolet curable resins 13 as the resins of the outermost layers of the respective
25 optical fibers 3, whereby the adhered portions 5 are formed, and the ribbon 1 is thereby
formed. That is to say, in the ribbon 1, the adhered portions 5 located on the more
outer circumferences of the ultraviolet curable resins 13 become the resins of the
outermost layers.
[0035]
3 0 On the outlet surface 17a of the coating dice 17, there are individually
provided disc-oriented groove portions 17c which penetrate the coating dice 17
between the respective optical fiber insertion holes 17b adjacent to one another and in
a Z-direction (up-and-down direction in FIG. 4) perpendicular to an X-direction
(direction where the plurality of optical fibers 3 are arranged in parallel to one another)
in FIG. 4. The respective disc-oriented groove portions 17c intersect the
above-described communication holes (not shown) formed between the optical fiber
insertion holes 17b adjacent to one another, and it is made possible to eject the
ultraviolet curable resin from the optical fiber insertion holes 17b through the
communication holes.
[0036]
A plurality of the discs 27 as the dam members are arranged in a state where
parts (upper portions in a rear side in the feeding direction of the optical fibers 3)
thereof enter the respective disc-oriented groove portions 17c. All of center portions
of the plurality of discs 27 are fixed to the same rotation shaft 29, and this rotation
shaft 29 is rotationally driven by a first drive source 31. When the rotation shaft 29
rotates by power of the first drive source 3 1, the plurality of discs 27 rotate integrally
with one another in a direction of an arrow B.
[0037]
Notched portions 27a are provided on outer circumferential portions of the
respective discs 27. Rotation orbits of the notched portions 27a are set so that the
notched portions 27a can pass through positions corresponding to the above-described
insertion holes (not shown) between the optical fiber insertion holes 17b adjacent to
one another.
[0038]
Hence, at positions where spots of the discs 27. which are other than the
notched portions 27a. are interposed between the disc-oriented groove portions 17c
between the optical fiber insertion holes 17b adjacent to one another, the discs 27 stops
the ejection of the ultraviolet curable resin, which is made through the communication
holes from the optical fiber insertion holes 17b adjacent to the discs 27 on both sides.
Meanwhile, when the notched portions 27a of the discs 27 are located at the
disc-oriented groove portions 17c between the optical fiber insertion holes 17b
adjacent to one another, the ultraviolet curable resin is ejected through the
communication holes from the optical fiber insertion holes 17b adjacent to the discs
27.
[0039]
Hence, the plurality of discs 27 in which rotation phases of the notched
5 portions 27a are different from one another are attached, and the plurality of discs 27
are rotated, whereby, as shown in FIG. 1 described above, the adhered portions 5 made
of the ultraviolet curable resin and the separated portions 7 can be formed individually
between the optical fibers 3 adjacent to one another. As a result, it is made possible
to manufacture the ribbon 1 in which the optical fibers 3 adjacent to one another are
10 fixed to one another intermittently along the longitudinal direction.
The resin removing means 23 includes: a brush 33 as a scraping member
extended radially from a rotation center thereof; a rotation shaft 35 to which a center
spot (base end portion) of the brush 33 is fixed; and a second drive source 37 that
15 rotationally drives the rotation shaft 35. The brush 33 that rotates contacts outer
circumferential edge portions of the respective discs 27, and scrape off the ultraviolet
curable resin stuck to the respective discs 27.
[004 1 ]
In this embodiment, the brush cleaning means 25 is a solution vessel in which
20 a detergent such as alcohol is housed, and this solution vessel (brush cleaning means)
25 is installed on a rotation orbit of the brush 33. When such a rotating brush 33
contacts the discs 27, the ultraviolet curable resin stuck to the surfaces of the discs 27
is shaved off by the brush 33, and the ultraviolet curable resin stuck to the brush 33 is
removed by the detergent in the solution vessel 25.
25 [0042]
In a space from the outlet surface 17a of the coating dice 17 to a spot where
the optical fibers 3 are concentrated so as to be arranged in parallel to one another and
are brought into contact with one another, at two spots thereof, the ultraviolet spot
lamps 19 are arranged in a Y-direction (feeding direction of the optical fibers 3)
30 corresponding to the longitudinal direction of the optical fibers 3. By the ultraviolet
spot lamps 19 located at two spots, resin curing energy necessaly to cure the uncured
ultraviolet curable resin is irradiated.
[0043]
Note that such installation positions and number of the ultraviolet spot lamps
19 are not limited to those shown in FIG. 4, and for example, three or more of the
5 ultraviolet spot lamps 19 may be arranged at appropriate positions between the coating
dice 17 and the line concentrating roll 21. Moreover, such an irradiation direction of
the ultraviolet ray is not limited to the Z-direction in FIG. 4, and may be other
directions such as the X-direction. In this event, with regard to the irradiation
direction of the ultraviolet ray, different directions may be combined with one another.
10 Furthermore, the ultraviolet lamps are not limited to those of the spot type, and those
0 with a relatively long shape, such as fluorescent tubes, may be used. Then,
installation positions, number and type of these ultraviolet lamps are changed
appropriately, and in addition, an ultraviolet irradiation dose is also adjusted
appropriately, whereby the curing of the uncured ultraviolet curable resin is made
15 sufficient.
[0044]
In the event where the optical fibers 3 are sent out from the optical fiber
insertion holes 17b at the time of manufacturing the ribbon 1 by the ribbon
manufacturing apparatus having such a configuration, outer circumferential surfaces of
20 the optical fibers 3 are rubbed by circumferential edges of opening portions of the
optical fiber insertion holes 17b as the outlet portions of the coating dice 17. With
regard to factors why the outer circumferential surfaces concerned are rubbed, such
rubbing is considered to necessarily occur because the optical fibers 3 swing because
of vibrations caused by the rotation of the discs 27, vibrations when the notched
25 portions 27a of the discs 27 pass through such coupling holes of the fiber insertion
holes 17b, and pulsation (vibrations) caused by a minute change of the coating amount
of the ultraviolet curable resin.
[0045]
At that time, in this embodiment, with regard to the ultraviolet curable resins
30 13 of the optical fibers 3, as mentioned above, it is essential that the Young's modulus
thereof be 300 MPa or more. In addition. when the Young's modulus is 300 MPa or
more to less than 600 MPa, the friction force measured by the above-described
measurement method is set at 0.3 N or less, whereby the slippage of the ultraviolet
curable resins 13 is enhanced.
[0046]
5 Therefore, even if the optical fibers 3 are rubbed by the outlet portions of the
coating dice 17, in the ultraviolet curable resins 13 made slippery by enhancing the
slippage, the occurrence of the shaved chip can be suppressed as shown in Table 1
mentioned above, and the ultraviolet curable resins 13 can be suppressed from being
shaved off.
10 [0047]
Note that, in the ribbon manufacturing apparatus shown in FIG. 4, the discs 27
are used as the dam members; those other than the discs 27, for example, shutters
moving up and down, can also be used in a similar way to those described in the
foregoing Patent Literature 1.
15 [0048]
Moreover, in this embodiment, in the measurement method of the friction
force, the diameter of the ring 30a is set at 7 cm as described with reference to FIG. 3;
however, may be a little smaller or larger than 7 cm. However, when the diameter of
the ring 30a is too small, then a fracture of the optical fiber specimen 30 is brought
20 about, and this is not preferable. On the contrary, when the diameter of the ring 30a is
too large, then it becomes difficult to set the ring 30a onto a testing machine to thereby
deteriorate workability, and this is not preferable. By setting the diameter concerned
at 7 cm, the fracture of the optical fiber specimen 30 is suppressed, and in addition, it
is made easy to set the ring 30a onto the testing machine, and based on these,
25 measurement with higher accuracy is enabled.
[0049]
Furthermore, in this embodiment, in the measurement method of the friction
force, the contact portion 30d is formed by repeating twice the work of inserting the
end portion 30b on one end side of the optical fiber specimen 30 into the ring 30a as
30 described with reference to FIG. 3; however, the number of times that the work
concerned is performed is not limited to twice. However, if the number of times
concerned is too large, then the workability is deteriorated, and it becomes difficult to
perform the high-accuracy measurement, and accordingly, this is not preferable. On
the contrary, if the number of times concerned is only once, then it becomes difficult to
perform the high-accuracy measurement, and accordingly, this is not preferable.
5 [0050]
Moreover, in this embodiment, in the measurement method of the friction
force, as described with reference to FIG. 3, the end portion 30b on one end side of the
optical fiber specimen 30 and the end portion 30c on the other end thereof are pulled at
the speed of 5 mrnlmin for 2 minutes; however, some errors are allowed for these
10 puling speed and time. These end portions 30b and 30c are pulled at the speed of 5 e mm/min for 2 minutes, whereby measurement with higher accuracy is enabled.

1. A manufacturing method of an optical fiber ribbon, in which a plurality of
optical fibers coated with a resin are arranged in parallel to one another, and these
5 respective optical fibers are fixed to one another intermittently along a longitudinal
direction thereof, the manufacturing method comprising:
arranging, in parallel to one another, a plurality of optical fibers in which a
Young's modulus of the coating resin on outermost layers is 300 MPa or more; and
connecting these respective optical fibers to one another intermittently along
10 the longitudinal direction.
2. The manufacturing method of an optical fiber ribbon according to claim 1 ,
wherein, when the Young's modulus of the coating resin on the outermost layers is 300
MPa or more to less than 600 MPa, a plurality of optical fibers in which friction force
15 of the coating resin on the outermost layers is 0.3 N or less are arranged in parallel to
one another, and the respective optical fibers are connected to one another
intermittently along the longitudinal direction.
3. An optical fiber ribbon, wherein the optical fiber ribbon is manufactured by
20 the manufacturing method of an optical fiber ribbon according to either one of claims 1
and 2.
Dated 23 December 2013
INPA- 1228
Agent for the Applicant
To,
The Controller of Patents
30 The Patent Office at New Delhi