(19)
(11)EP 3 816 690 A1

(12)EUROPEAN PATENT APPLICATION

(43)Date of publication:
05.05.2021 Bulletin 2021/18

(21)Application number: 20202643.1

(22)Date of filing:  19.10.2020
(51)International Patent Classification (IPC): 
G02B 6/44(2006.01)
G02B 6/52(2006.01)
(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA ME
Designated Validation States:
KH MA MD TN

(30)Priority: 29.10.2019 CN 201911039699

(71)Applicant: Hengtong Optic-Electric Co., Ltd
Suzhou, Jiangsu 215234 (CN)

(72)Inventors:
  • LI, Wei
    Suzhou, Jiangsu 215234 (CN)
  • ZHOU, Feng
    Suzhou, Jiangsu 215234 (CN)
  • WU, Binhua
    Suzhou, Jiangsu 215234 (CN)
  • FEI, Huaqing
    Suzhou, Jiangsu 215234 (CN)
  • WANG, Rui
    Suzhou, Jiangsu 215234 (CN)
  • SUN, Lihua
    Suzhou, Jiangsu 215234 (CN)
  • LIU, Peidong
    Suzhou, Jiangsu 215234 (CN)
  • SHI, Huiping
    Suzhou, Jiangsu 215234 (CN)

(74)Representative: Sach, Greg Robert 
Sach & Associates Siedlungsstrasse 4a
85253 Erdweg
85253 Erdweg (DE)

  


(54)ULTRAHIGH-DENSITY LARGE-CORE-NUMBER AIR-BLOWING MICRO-CABLE AND PROCESS OF MANUFACTURING THE SAME


(57) The invention provides an ultrahigh-density large-core-number air-blowing micro-cable. The ultrahigh-density large-core-number air-blowing micro-cable comprises loose tubes formed by at most 48 pieces of 200-μm small-size optical fibers, each loose tube is used as a subunit to prepare the ultrahigh-density large-core-number air-blowing micro-cable which is advantageous in terms of low weight, small cable diameter and high optical fiber density. The ultrahigh-density large-core-number air-blowing micro-cable includes a central reinforcing piece, at least one optical unit twisting layer annularly distributed on a periphery of the central reinforcing piece and a relatively outer optical unit twisting layer twisted at a periphery formed by a relatively inner optical unit twisting layer. Each optical unit twisting layer includes a plurality of identical subunits, the subunits in different optical unit twisting layers are the same and a number of the subunits of the relatively outer optical unit twisting layer is larger than that of the subunits of the relatively inner optical unit twisting layer. Each loose tube is filled with factice, and a periphery of an outermost optical unit twisting layer is coated with an outer PE sheath.




Description

FIELD



[0001] The present invention relates to the technical field of photoelectric composite cable structures, and more particularly, to an ultrahigh-density large-core-number air-blowing micro-cable, and the present invention further provides a process of manufacturing the air-blowing micro-cable.

BACKGROUND



[0002] With increasingly high requirements of global communication services for a network bandwidth, optical fiber communication is widely used as the fastest communication mode with the best transmission quality. However, in network construction, with the shortage of pipeline resources, higher requirements are placed on pipelines in terms of space utilization, construction efficiency and convenience of maintenance. As a mature optical cable network laying technology, air-blowing micro-tube and micro-cable technology has been widely promoted in an international market due to its excellent comprehensive performance and unique laying mode. The increasing demand for air-blowing micro-cables promotes optical cables to develop towards large core number and small cable diameter.

[0003] In a traditional layer-twisting air-blowing micro-cable, more than four tubes of 2-24 cores are generally twisted around a central reinforcing piece to form a cable core, and then the optical cable is formed using a polyethylene sheath. At present, urban pipelines are increasingly short, and existing pipeline resources fail to be fully used, thus greatly affecting a competitiveness of products. Therefore, it is very important to reduce an equivalent area of the same number of optical fibers in the tube, increase an optical fiber density of the optical cable with the same number of cores, reduce an outer diameter of the optical cable and be compatible with a small-size air-blowing micro-cable.

SUMMARY



[0004] Aiming at the above problems, the present invention provides an ultrahigh-density large-core-number air-blowing micro-cable. Plastic coating is carried out by using 200-µm small-size optical fibers and a loose tube formed by at most 48 pieces of optical fibers is used as a subunit to prepare an ultrahigh-density large-core-number air-blowing micro-cable, which is advantageous in low weight, small cable diameter and high optical fiber density, thus meeting a demand for urban pipeline installation.

[0005] An ultrahigh-density large-core-number air-blowing micro-cable is provided including a central reinforcing piece, wherein at least one optical unit twisting layer is annularly distributed on a periphery of the central reinforcing piece, a relatively outer optical unit twisting layer is twisted at a periphery formed by a relatively inner optical unit twisting layer, each optical unit twisting layer includes a plurality of identical subunits, the subunits in different optical unit twisting layers are same, a number of the subunits of the relatively outer optical unit twisting layer is larger than that of the subunits of the relatively inner optical unit twisting layer, each subunit includes a loose tube in which at most 48 pieces of 200-µm small-size optical fibers are arranged, the loose tube is filled with factice, and a periphery of an outermost optical unit twisting layer is coated with an outer PE sheath.

[0006] Further, the central reinforcing piece is a small-diameter central reinforcing piece with a diameter not greater than an outer diameter of the corresponding loose tube of the subunit;
the central reinforcing piece is specifically made of high modulus FRP with a modulus greater than 56 GPa, and a water-blocking yarn is arranged in a gap between the central reinforcing piece and an inner periphery of the inner optical unit twisting layer;
a further water-blocking yarn is arranged in a gap between the relatively outer optical unit twisting layer and the relatively inner optical unit twisting layer;
a rip cord is arranged on an inner wall of the outer PE sheath, and a wall thickness of the outer PE sheath is 0.4 mm;
when a total number of cores is 288, six subunits are annularly distributed on the periphery of the central reinforcing piece, 48 pieces of 200-µm small-size optical fibers are arranged in the loose tube of each subunit, and then peripheries of the six subunits are coated with the outer PE sheaths;
when the total number of cores is 864, the ultrahigh-density large-core-number air-blowing micro-cable includes a first optical unit twisting layer and a second optical unit twisting layer, the first optical unit twisting layer includes six subunits, the second optical unit twisting layer includes 12 subunits, 48 pieces of 200-µm small-size optical fibers are arranged in the loose tube of each subunit, a first optical unit is twisted at the periphery of the central reinforcing piece, a second optical unit is twisted at a periphery of the first optical unit, and a periphery of the second optical unit is coated with the outer PE sheath; and
when the total number of cores is 1728, the ultrahigh-density large-core-number air-blowing micro-cable includes the first optical unit twisting layer, the second optical unit twisting layer and a third optical unit twisting layer, the first optical unit twisting layer includes six subunits, the second optical unit twisting layer includes 12 subunits, the third optical unit twisting layer includes 18 subunits, 48 pieces of 200-µm small-size optical fibers are arranged in the loose tube of each subunit, the first optical unit is twisted at the periphery of the central reinforcing piece, the second optical unit is twisted at the periphery of the first optical unit, a third optical unit is twisted at the periphery of the second optical unit, and a periphery of the third optical unit is coated with the outer PE sheath.

[0007] A process of manufacturing an air-blowing micro-cable in provided including: assigning optical fibers, and coloring, or printing with a color ring according to a chromatography, 48 pieces of small-size optical fibers, wherein the optical fibers with serial numbers of 1 to 12 are colored and optical fibers with various serial numbers have different colors, and the optical fibers with serial numbers of 13 to 24, 25 to 36 and 37 to 48 are printed with a color ring according to color rings of different numbers and different colors within a unit distance, so that 48 pieces of optical fibers in each subunit are able to be quickly distinguished;
delivering the 48 pieces of optical fibers into a loose tube by evenly controlling an extrusion amount of PBT in a loose tube procedure, while filling the loose tube with a small amount of factice to ensure stability in outer diameter of the loose tube, wherein length difference and stability in outer diameter of the optical fibers are controlled by an optical fiber twisting device;
providing a central reinforcing piece which is made of high modulus FRP with a modulus greater than 56 GPa, placing a water-blocking yarn around the central reinforcing piece, providing a plurality of optical unit twisting layers in an extension direction of the central reinforcing piece, wherein each optical unit twisting layer is formed by combining a plurality of subunits, and all the subunits and non-metallic reinforcing pieces form a cable core with a stable structure through an SZ twisting procedure; and
coating a layer of PE material outside the cable core to form an outer PE sheath.

[0008] Further, a semi-dry structure is used, the loose tube is filled with the factice, and the water-blocking yarn is used in the cable core, thus reducing use of the factice and protecting environment;
a single loose tube of the subunit has an outer diameter of 2.1 mm±0.05 mm, and a wall thickness of 0.15 mm±0.03 mm; and
the optical fibers with the serial numbers of 13 to 24, 25 to 36 and 37 to 48 are printed with the color ring respectively according to the color rings of different numbers and different colors within the unit distance of 50 mm, each color ring has a width of 2 mm, model with one color ring within the unit distance is a first model, model with two color rings within the unit distance are a second model, model with three color rings within the unit distance are a third model, an interval between adjacent color rings within each unit distance is 3 mm, and corresponding models are respectively selected to print the color ring for the optical fibers with the serial numbers of 13 to 24, 25 to 36 and 37 to 48.

[0009] After using the present invention, compared with a traditional layer-twisting air-blowing micro-cable, the outer diameter is reduced by about 10% to 25% under the same number of cores, the number of cores of the optical fiber per unit area is increased by 22% to 91%, the present invention has characteristics of a high optical fiber density, a large number of cores and a small cable diameter, which can effectively improve the pipeline utilization, and a 1728-core air-blowing micro-cable with an optical fiber density up to about 89% can be prepared by multi-layer twisting of the maximum number of cores. The present invention adopts a semi-dry design in which the loose tube is filled with the factice, and the water-blocking yarn is used in the cable core, thus reducing use of the factice and protecting environment. Moreover, the present invention adopts a design of thin-walled tube and sheath structure, thus improving the optical fiber density of the optical cable, further reducing the cable weight, improving a laying convenience of the optical cable and reducing a construction intensity. The present invention supplements and enriches series of the air-blowing micro-cable.

BRIEF DESCRIPTION OF THE DRAWINGS



[0010] 

FIG. 1 is a cross-sectional structure diagram of the embodiment 1 of an optical cable of the present invention;

FIG. 2 is a cross-sectional structure diagram of the embodiment 2 of the optical cable of the present invention;

FIG. 3 is a cross-sectional structure diagram of the embodiment 3 of the optical cable of the present invention; and

FIG. 4 is a diagram of a color ring of an optical fiber of the present invention.



[0011] Numerals in FIG. 2 correspond to names as follows:
1 refers to central reinforcing piece, 2 refers to subunit, 3 refers to loose tube, 4 refers to optical fiber, 5 refers to factice, 6 refers to outer PE sheath, 7 refers to water-blocking yarn, and 8 refers to rip cord.

DETAILED DESCRIPTION OF THE EMBODIMENTS



[0012] As shown in FIG. 1 to FIG. 3, an ultrahigh-density large-core-number air-blowing micro-cable includes a central reinforcing piece 1, wherein at least one optical unit twisting layer is annularly distributed on a periphery of the central reinforcing piece 1. A relatively outer optical unit twisting layer is twisted at a periphery formed by a relatively inner optical unit twisting layer, each optical unit twisting layer includes a plurality of identical subunits 2, and the subunits 2 in different optical unit twisting layers are same. A number of the subunits of the relatively outer optical unit twisting layer is larger than that of the subunits of the relatively inner optical unit twisting layer, each subunit 2 includes a loose tube 3 in which at most 48 pieces of 200-µm small-size optical fibers 4 are arranged. The loose tube 4 is filled with factice 5, and a periphery of an outermost optical unit twisting layer is coated with an outer PE sheath 6.

[0013] The central reinforcing piece 1 is a small-diameter central reinforcing piece with a diameter not greater than an outer diameter of the corresponding loose tube 3 of the subunit 2.

[0014] The central reinforcing piece 1 is specifically made of high modulus FRP with a modulus greater than 56 GPa, and a water-blocking yarn 7 is arranged in a gap between the central reinforcing piece 1 and an inner periphery of the inner optical unit twisting layer.

[0015] A further water-blocking yarn 7 is arranged in a gap between the relatively outer optical unit twisting layer and the relatively inner optical unit twisting layer.

[0016] A rip cord 8 is arranged on an inner wall of the outer PE sheath 6, and a wall thickness of the outer PE sheath 6 is 0.4 mm.

[0017] In embodiment 1, with reference to FIG. 1, when the total number of cores is 288, six subunits 2 are annularly distributed on the periphery of the central reinforcing piece 1. 48 pieces of 200-µm small-size optical fibers 3 are arranged in the loose tube 3 of each subunit 2, and then peripheries of the six subunits 2 are coated with the outer PE sheath 6.

[0018] In embodiment 2, with reference to FIG. 2, when the total number of cores is 864, the ultrahigh-density large-core-number air-blowing micro-cable includes a first optical unit twisting layer and a second optical unit twisting layer, the first optical unit twisting layer includes six subunits 2, and the second optical unit twisting layer includes 12 subunits 2. 48 pieces of 200-µm small-size optical fibers 4 are arranged in the loose tube 3 of each subunit 2, a first optical unit is twisted at the periphery of the central reinforcing piece 1, a second optical unit is twisted at a periphery of the first optical unit, and a periphery of the second optical unit is coated with the outer PE sheath 6.

[0019] In embodiment 2, with reference to FIG. 3, when the total number of cores is 1728, the ultrahigh-density large-core-number air-blowing micro-cable includes the first optical unit twisting layer, the second optical unit twisting layer and a third optical unit twisting layer, the first optical unit twisting layer includes six subunits 2, the second optical unit twisting layer includes 12 subunits 2, and the third optical unit twisting layer includes 18 subunits 2. 48 pieces of 200-µm small-size optical fibers 4 are arranged in the loose tube 3 of each subunit 2, the first optical unit is twisted at the periphery of the central reinforcing piece 1, the second optical unit is twisted at the periphery of the first optical unit, a third optical unit is twisted at the periphery of the second optical unit, and a periphery of the third optical unit is coated with the outer PE sheath 6.

[0020] A process of manufacturing an air-blowing micro-cable is provided. Optical fibers are assigned first, and then 48 pieces of small-size optical fibers are colored or printed with a color ring according to a chromatography. The optical fibers with serial numbers of 1 to 12 are colored and optical fibers with various serial numbers have different colors, and the optical fibers with serial numbers of 13 to 24, 25 to 36 and 37 to 48 are printed with a color ring according to color rings of different numbers and different colors within a unit distance, so that 48 pieces of optical fibers in each subunit are able to be quickly distinguished.

[0021] 48 pieces of optical fibers are sent into the loose tube by evenly controlling an extrusion amount of PBT in the loose tube procedure. Meanwhile, the loose tube is filled with a small amount of factice to ensure stability in outer diameter of the loose tube. At the same time, length difference and stability in outer diameter of the optical fibers are controlled by an optical fiber twisting device.

[0022] The central reinforcing piece is made of high modulus FRP with a modulus greater than 56 GPa, and a water-blocking yarn is placed around the central reinforcing piece. A plurality of optical unit twisting layers are arranged in an extension direction of the central reinforcing piece, each optical unit twisting layer is formed by combining a plurality of subunits, and all the subunits and non-metallic reinforcing piece form a cable core with a stable structure through an SZ twisting procedure.

[0023] Then, a layer of PE material is coated outside the cable core to form an outer PE sheath.

[0024] A semi-dry structure is used, the loose tube is filled with the factice, and the water-blocking yarn is used in the cable core, thus reducing use of the factice and protecting environment.

[0025] A single loose tube of the subunit has an outer diameter of 2.1 mm±0.05 mm, and a wall thickness of 0.15 mm±0.03 mm.

[0026] Referring to FIG. 4 specifically for color ring models, the optical fibers with the serial numbers of 13 to 24, 25 to 36 and 37 to 48 are printed with the color ring respectively according to the color rings of different numbers and different colors within the unit distance of 50 mm, and each color ring has a width of 2 mm. Model with one color ring within the unit distance is a first model S50, model with two color rings within the unit distance is a second model D50, and model with three color rings within the unit distance is a third model T50. An interval between adjacent color rings within each unit distance is 3 mm, and corresponding models are respectively selected to print the color ring for the optical fibers with the serial numbers of 13 to 24, 25 to 36 and 37 to 48.

[0027] Compared with a traditional layer-twisting air-blowing micro-cable, the outer diameter is reduced by about 10% to 25% for the same number of cores, the number of cores of the optical fiber per unit area is increased by 22% to 91%, the present invention has characteristics of a high optical fiber density, a large number of cores and a small cable diameter, which can effectively improve the pipeline utilization, and a 1728-core air-blowing micro-cable with an optical fiber density up to about 89% can be prepared by multi-layer twisting of the maximum number of cores. The present invention adopts a semi-dry design in which the loose tube is filled with the factice, and the water-blocking yarn is used in the cable core, thus reducing use of the factice and protecting environment. Moreover, the present invention adopts a design of thin-walled tube and sheath structure, thus improving the optical fiber density of the optical cable, further reducing the cable weight, improving a laying convenience of the optical cable and reducing a construction intensity. The present invention supplements and enriches series of the air-blowing micro-cable.

[0028] It is apparent for those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be realized in other specific forms without departing from the concept or basic features of the present invention. Therefore, the embodiments should be regarded as being exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, so that it is intended to include all changes falling within the meaning and scope of equivalent elements of the claims. Any reference numerals in the claims should not be regarded as limiting the claims involved.

[0029] In addition, it should be understood that although the description is described according to the embodiments, each embodiment does not contain only one independent technical solution. The narration mode of the description is only for purpose of clarifying, and those skilled in the art should take the description as a whole. The technical solutions in each embodiment may also be combined appropriately to form other embodiments that may be understood by those skilled in the art.


Claims

1. An ultrahigh-density large-core-number air-blowing micro-cable, comprising a central reinforcing piece, wherein at least one optical unit twisting layer is annularly distributed on a periphery of the central reinforcing piece, a relatively outer optical unit twisting layer is twisted at a periphery formed by a relatively inner optical unit twisting layer, each optical unit twisting layer comprises a plurality of identical subunits, the subunits in different optical unit twisting layers are same, a number of the subunits of the relatively outer optical unit twisting layer is larger than a number of the subunits of the relatively inner optical unit twisting layer, each subunit comprises a loose tube in which at most 48 pieces of 200µm small-size optical fibers are arranged, the loose tube is filled with factice, and a periphery of an outermost optical unit twisting layer is coated with an outer PE sheath.
 
2. The ultrahigh-density large-core-number air-blowing micro-cable according to claim 1, wherein the central reinforcing piece is a small-diameter central reinforcing piece with a diameter not greater than an outer diameter of the corresponding loose tube of the subunit.
 
3. The ultrahigh-density large-core-number air-blowing micro-cable according to claim 1, wherein the central reinforcing piece is specifically made of high modulus FRP with a modulus greater than 56 GPa, and a water-blocking yarn is arranged in a gap between the central reinforcing piece and an inner periphery of the inner optical unit twisting layer.
 
4. The ultrahigh-density large-core-number air-blowing micro-cable according to claim 1, wherein at least two pieces of water-blocking yarns are placed on an outer surface of an inner sheath in a cross way, and a density of the water-blocking yarns is 400 dtex to 1000 dtex.
 
5. The ultrahigh-density large-core-number air-blowing micro-cable according to claim 1, wherein a water-blocking yarn is arranged in a gap between the relatively outer optical unit twisting layer and the relatively inner optical unit twisting layer.
 
6. The ultrahigh-density large-core-number air-blowing micro-cable according to claim 1, wherein a rip cord is arranged on an inner wall of the outer PE sheath, and a wall thickness of the outer PE sheath is 0.4 mm.
 
7. A process of manufacturing an air-blowing micro-cable, comprising:

assigning optical fibers, and coloring, or printing with a color ring according to a chromatography, 48 pieces of small-size optical fibers, wherein the optical fibers with serial numbers of 1 to 12 are colored and optical fibers with various serial numbers have different colors, and the optical fibers with serial numbers of 13 to 24, 25 to 36 and 37 to 48 are printed with a color ring according to color rings of different numbers and different colors within a unit distance, so that 48 pieces of optical fibers in each subunit are able to be quickly distinguished;

delivering the 48 pieces of optical fibers into a loose tube by evenly controlling an extrusion amount of PBT in a loose tube procedure, while filling the loose tube with a small amount of factice to ensure stability in outer diameter of the loose tube, wherein length difference and stability in outer diameter of the optical fibers are controlled by an optical fiber twisting device;

providing a central reinforcing piece which is made of high modulus FRP with a modulus greater than 56 GPa, placing a water-blocking yarn around the central reinforcing piece, providing a plurality of optical unit twisting layers in an extension direction of the central reinforcing piece, wherein each optical unit twisting layer is formed by combining a plurality of subunits, and all the subunits and non-metallic reinforcing pieces form a cable core with a stable structure through an SZ twisting procedure; and

coating a layer of PE material outside the cable core to form an outer PE sheath.


 
8. The process of manufacturing the air-blowing micro-cable according to claim 7, wherein a semi-dry structure is used, the loose tube is filled with the factice, and the water-blocking yarn is used in the cable core, thus reducing use of the factice and protecting environment.
 
9. The process of manufacturing the air-blowing micro-cable according to claim 7, wherein a single loose tube of the subunit has an outer diameter of 2.1 mm±0.05 mm, and a wall thickness of 0.15 mm±0.03 mm.
 
10. The process of manufacturing the air-blowing micro-cable according to claim 7, wherein the optical fibers with the serial numbers of 13 to 24, 25 to 36 and 37 to 48 are printed with the color ring respectively according to the color rings of different numbers and different colors within the unit distance of 50 mm, each color ring has a width of 2 mm, model with one color ring within the unit distance is a first model, model with two color rings within the unit distance is a second model, model with three color rings within the unit distance is a third model, an interval between adjacent color rings within each unit distance is 3 mm, and corresponding models are respectively selected to print the color ring for the optical fibers with the serial numbers of 13 to 24, 25 to 36 and 37 to 48.
 




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