CN110426803B

CN110426803B - All-dry type microbeam optical cable

Info

Publication number: CN110426803B
Application number: CN201910818373.2A
Authority: CN
Inventors: 汪趁时; 李新建; 缪威玮; 陆杰; 周华; 李强
Original assignee: Jiangsu Zhongtian Technology Co Ltd
Current assignee: Jiangsu Zhongtian Technology Co Ltd
Priority date: 2019-08-30
Filing date: 2019-08-30
Publication date: 2024-04-30
Anticipated expiration: 2039-08-30
Also published as: WO2021036111A1; CN110426803A

Abstract

The invention provides a full-dry microbeam optical cable, which comprises a microtube core, an outer sheath coated on the periphery of the microtube core and a plurality of reinforcing pieces embedded in the outer sheath, wherein the microtube core comprises a plurality of winding microtubes and a plurality of water-blocking yarns, and the water-blocking yarns are filled in gaps between the winding microtubes; the winding and bundling microtubes comprise winding and bundling belts, a plurality of dry optical fiber microtubes wrapped by the winding and bundling belts and a plurality of water-blocking yarns, and each dry optical fiber microtube consists of a microtube sheath, the water-blocking yarns wrapped by the microtube sheath and optical fibers. The invention adopts a full dry structure, is filled with oil paste, is environment-friendly and pollution-free, and is efficient and quick in construction; after the winding ribbon is adopted to wind and combine a plurality of dry optical fiber microtubules, the optical fiber density and the space occupation ratio of the optical fiber in the inner cavity of the sheath can be effectively improved; the dry water-blocking material has stable performance along with temperature change, and the optical fiber transmission characteristic does not change along with temperature change, so that the performance is stable.

Description

All-dry type microbeam optical cable

Technical Field

The invention relates to the technical field of optical cables, in particular to a full-dry type microbeam optical cable.

Background

Microbeam optical cables are generally used in urban backbone networks, and are usually laid by outdoor pipelines or overhead pipelines, so that special requirements are imposed on the water blocking performance of the optical cables, and the optical cables must be prevented from longitudinal seepage. The main structure of the microbeam optical cable comprises a microbeam tube and an outer sheath, wherein the microbeam tube contains at least 1 optical fiber, and at least 1 reinforcing piece is embedded in the sheath. In order to meet the requirement of the optical cable on full-section water blocking, the cavity between the outside of the microbeam tube and the sheath is required to be water-blocked, and the inside of the microbeam tube is also filled with water-blocking materials. In general, the water-blocking material in the microbeam tube is filled with an ointment, and the ointment comprises at least one liquid and a thickening agent, wherein the liquid is silicone oil, fluorinated oil or a mixture thereof, and the thickening agent is silicon dioxide, bentonite, polytetrafluoroethylene or a mixture thereof.

The following problems may exist with ointment filling: 1) The ointment mainly contains silicone oil, the silicone oil is a general chemical synthetic product, the natural degradation capability is low, and the environment is easy to be polluted for a long time; 2) In the process of installing and using the optical cable, the ointment is troublesome to clean, and is usually treated by adopting an organic solvent, so that the optical cable is not environment-friendly and has low efficiency; 3) The ointment is contacted with the optical fiber coloring layer, so that the coloring layer is easy to fall off or migrate, difficult to distinguish and difficult to connect; 4) When the temperature changes, the viscosity of the ointment changes, and the attenuation of the optical fiber possibly becomes high; 5) The contact area of the ointment and the microbeam tube protective sleeve is large, the filling volume of the ointment exceeds 85 percent of the inner diameter of the microbeam tube, and the protective sleeve leakage phenomenon can occur for a long time. 6) In the prior art, a plurality of microbeam tubes are generally adopted for direct twisting, so that the optical fiber density of the product is low and the outer diameter is large.

Disclosure of Invention

In view of the above, there is a need for an improved all-dry microbeam cable.

The technical scheme provided by the invention is as follows: the all-dry microbeam optical cable comprises a microtube core, an outer sheath coated on the periphery of the microtube core and a plurality of reinforcing pieces embedded in the outer sheath, wherein the microtube core comprises a plurality of winding microtubes and a plurality of water blocking yarns, and the water blocking yarns are filled in gaps between the winding microtubes; the winding and bundling microtubes comprise winding and bundling belts, a plurality of dry optical fiber microtubes wrapped by the winding and bundling belts and a plurality of water-blocking yarns, each dry optical fiber microtube consists of a microtube sheath, the water-blocking yarns wrapped by the microtube sheath and optical fibers, and the optical fiber density in an optical cable inner cavity is as follows:

Wherein: the density unit of the optical fiber is F/mm ²; n is the number of optical fibers; k is a correction coefficient, and the value is 0.5-1.0mm; m ₁ is the thickness of the winding belts, the unit is mm, and N ₁ is the number of the winding belts; n ₂ is the equivalent number of water blocking yarns; n ₃ is the number of the dry optical fiber microtubes, and D ₂ is the outer diameter of the dry optical fiber microtubes in mm.

Further, the density of the optical fibers in the inner cavity of the optical cable is 3.8-10F/mm ².

Further, the ratio of the equivalent circumference diameters of a plurality of optical fibers in the dry optical fiber microtube in the inner cavity of the microtube sheath is less than 90% and more than or equal to 70%, and the water blocking yarn accounts for 20% or less of the surface area of the inner cavity of the microtube sheath.

Further, the equivalent circumference diameter of a plurality of optical fibers in the dry optical fiber microtube is between 70% and 80% of the inner cavity of the sheath of the microtube.

Further, the materials of the microtube sheath comprise olefin polymer and inorganic filler, wherein the inorganic filler accounts for 0.1% -20% of the total mass of all components of the microtube sheath; the olefin polymer comprises a first olefin polymer or an ethylene/propylene copolymer with other monomers or other types of polymers, wherein the first olefin polymer comprises one of a linear low density polyethylene, poly-4-methyl-1-pentene, or an ethylene propylene copolymer; wherein the ethylene/propylene and other monomer copolymer comprises one or more of ethylene-alkyd ethylene copolymer, ethylene-methyl acrylate copolymer and ethylene-butyl acrylate copolymer; the inorganic filler comprises hydroxide, hydrous oxide, metal salt or a mixture thereof, or carbon black, silicon dioxide, kaolin, clay or a mixture thereof; the thickness of the microtube sheath is 0.1-0.2mm. Wherein the hydroxide may comprise aluminum hydroxide, magnesium hydroxide, the hydrated oxide may be hydrated aluminum oxide, hydrated magnesium carbonate, the metal salt may be zinc oxide, calcium carbonate, cobalt oxide, etc.

Further, a reinforcing layer is coaxially arranged between the microtube core and the outer sheath, and the material of the reinforcing layer comprises any one of aramid fiber, glass fiber yarn or polyester yarn, or the combination of water blocking yarn and one or more of aramid fiber, glass fiber yarn or polyester yarn.

Further, a water blocking belt coaxially arranged is further arranged between the microtube core and the outer sheath, and the water blocking belt is a double-sided water blocking belt.

Furthermore, the inside of the water blocking belt also comprises a plurality of embedded tearing ropes, and the tearing ropes are made of aramid or polyester yarns.

Further, the material of the outer sheath is polyolefin material; the reinforcing piece is a glass fiber reinforced plastic rod with the density of 2.05-2.15 g/cm ³.

Further, the water blocking yarns disposed in the various structural layers within the microtube core are typically water absorbing fibers that are capable of being free of water powder falling during production of the microtube core, and which contain acrylic acid, polyacrylic acid, acrylic acid salts, or their modified substances, or mixtures thereof.

Compared with the prior art, the full-dry type microbeam optical cable provided by the invention adopts a full-dry type structure, is filled with oil paste, is environment-friendly and pollution-free, and is efficient and quick in construction; after the winding ribbon is adopted to wind and combine a plurality of dry optical fiber microtubules, the optical fiber density and the space occupation ratio of the optical fiber in the inner cavity of the sheath can be effectively improved; the dry water-blocking material has stable performance along with temperature change, and the optical fiber transmission characteristic does not change along with temperature change, so that the performance is stable.

Drawings

The invention will be described in further detail with reference to the drawings and the detailed description.

FIG. 1 is a schematic diagram of an embodiment of an easily strippable dry-type optical fiber microtube.

Fig. 2 is a cross-sectional view of a full dry microbeam cable using the microtube structure of fig. 2.

Fig. 3 is a cross-sectional structure II of a full dry microbeam cable using the microtube structure of fig. 2.

Fig. 4 is a cross-sectional structure III of a full dry microbeam cable using the microtube structure of fig. 2.

Fig. 5 is a cross-sectional view of a fourth embodiment of a full dry microbeam cable using the microtube structure of fig. 2.

Fig. 6 is a cross-sectional view of a fifth embodiment of a full dry microbeam cable employing the microtube structure of fig. 2.

Fig. 7 is a cross-sectional view of a six-section full dry microbeam cable using the microtube structure of fig. 2.

Reference numerals illustrate:

Microtube sheath 1

Optical fiber 2

Dry optical fiber microtube 20

Water-blocking yarn 3

All-dry microbeam cable 100

Outer sheath 30

Stiffener 31

Water-blocking tape 40

Tear cord 41

Reinforcing layer 50

Wrap tie 80

Winding microtubule 82

Micro-die 84

The following detailed description will further illustrate embodiments of the invention in conjunction with the above-described drawings.

Detailed Description

In order that the above-recited objects, features and advantages of embodiments of the present application can be more clearly understood, a more particular description of the application will be rendered by reference to the appended drawings and appended detailed description. The features of the embodiments of the present application may be combined with each other without collision.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the invention, and the described embodiments are merely some, rather than all, of the embodiments of the invention. All other embodiments, based on the embodiments of the invention, which are obtained by a person of ordinary skill in the art without making any inventive effort, are within the scope of the embodiments of the invention.

The term "SZ twist" as used herein refers to a left-right twist. The twisting direction of the twisting has left and right directions, the left direction is similar to S, the right direction is similar to Z, the left direction is also similar to S.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the invention belong. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Referring to fig. 1, the present invention provides an easily-stripped dry optical fiber microtube 20, which comprises a plurality of optical fibers 2, a plurality of water-blocking yarns 3 and a microtube sheath 1, wherein the microtube sheath 1 is coated outside the plurality of optical fibers 2 and the plurality of water-blocking yarns 3, no filler is arranged in the gaps between the inner cavity of the microtube sheath 1 and the plurality of optical fibers 2 and/or the plurality of water-blocking yarns 3, and the water-blocking yarns occupy less than or equal to 20% of the inner cavity space. Namely, the paint does not contain ointment filling, and avoids the falling or migration of a coloring layer, so that the connection is easier to construct, and the paint is environment-friendly and efficient.

The surface layer of the optical fiber 2, usually a single-mode optical fiber, is provided with a protective coating; when a plurality of optical fibers 2 are present in each microtube sheath 1, they can be distinguished by coloring, i.e. forming colored optical fibers. The diameter of the individual fibers 2 may be nominally 250 μm, 200 μm or 180 μm. The plurality of optical fibers 2 are typically SZ stranded within the microtube jacket 1. The equivalent diameter formula of the plurality of optical fibers is as follows: d=1.16×n ^1/2 ×d, where n is the number of fibers and D is the colored fiber diameter.

The dry optical fiber microtube 20 comprises at least 1 water blocking yarn 3, wherein the density of the water blocking yarn is generally 200-800Denier (Denier is also called Denier), the tensile strength is more than or equal to 12N, the elongation at break is more than or equal to 12%, the thermal shrinkage rate is less than or equal to 3.5%, the expansion rate is more than or equal to 25ml/g/min, the expansion rate is more than or equal to 30ml/g, and the water content is less than or equal to 8%. The water-blocking yarn 3 is prepared by solidifying water-absorbing resin or water-absorbing fiber on a basic yarn through a process, and no water powder falls off in the production process of the optical fiber microtubule, wherein the water-absorbing resin and the water-absorbing fiber usually contain acrylic acid, polyacrylic acid, acrylic acid salt or modified substances or mixtures thereof, and the modified substances can be acrylic acid grafted copolymers, such as acrylic acid grafted modified polyethylene terephthalate. The water-blocking yarn 3 occupies 20% or less of the inner cavity surface area of the microtube sheath.

The thickness of the microtube sheath 1 in the dry optical fiber microtube 20 is 0.1-0.2mm; the material of the microtube sheath 1 comprises an olefin polymer and an inorganic filler, wherein the inorganic filler accounts for 0.1% -20% of the total mass of all components of the microtube sheath, the olefin polymer comprises a first olefin polymer or an ethylene/propylene copolymer with other monomers, and the first olefin polymer comprises one of linear low density polyethylene, poly-4-methyl-1-pentene or ethylene propylene copolymer; the ethylene/propylene and other monomer copolymers comprise one or a mixture of more of ethylene-alkyd ethylene copolymer, ethylene-methyl acrylate copolymer and ethylene-butyl acrylate copolymer, the Shore hardness H _A is less than or equal to 90, and the optical fiber microtube sheath 1 can be easily torn off by hand by at least 1 meter. The inorganic filler may be a hydroxide, a hydrated oxide, a metal salt or a mixture thereof, wherein the hydroxide may comprise aluminum hydroxide, magnesium hydroxide, the hydrated oxide may be hydrated aluminum oxide, hydrated magnesium carbonate, the metal salt may be zinc oxide, calcium carbonate, cobalt oxide, or the like; the inorganic filler may also be carbon black, silica, kaolin, clay, etc. The equivalent circumferential diameter of the optical fiber accounts for the proportion X of the inner diameter of the microtube sheath, and X is more than or equal to 70% and less than 90%, preferably 70-80%. Wherein the inorganic filler reduces the toughness of the material so that the optical fiber microtube sheath can be easily torn off by at least 1 meter without the aid of a tool. Meanwhile, the shrinkage of the material can be reduced by adding the inorganic filler, the shrinkage rate of the material can be regulated and controlled to be less than 3% in the proportion range, the optical fiber microtubule does not shrink in the connector box, and the communication stability of the optical cable communication line can be ensured.

The following invention illustrates the structure and performance of the easy-peel dry fiber microtube 20.

Example 1

In this example, the number of cores of the optical fiber of the easily-peelable dry optical fiber microtube 20 is 6, as shown in fig. 1.

Each optical fiber microtube 20 is internally provided with 6 optical fibers, the colors of the optical fibers 2 are blue, orange, green, brown, gray and white, the optical fibers adopt G.652D optical fibers, the diameter of the colored optical fiber coating is 250 mu m +/-15 mu m, and the optical fibers in the microtube adopt SZ twisted.

Each optical fiber microtube 20 contains 1 300D water-blocking yarn 3, the linear density of the water-blocking yarn 3 is 30000m/kg, and the performance type selection requirements are that: the tensile strength is more than or equal to 12N, the elongation at break is more than or equal to 12%, the thermal shrinkage is less than or equal to 3.5%, the expansion rate is more than or equal to 25ml/g/min, the expansion rate is more than or equal to 30ml/g, and the water content is less than or equal to 8%. In this example, the water-absorbing fiber containing acrylate is mainly made of terylene or chinlon.

The wall thickness of the microtube sheath 1 is 0.1mm, the microtube sheath 1 is made of a mixture of linear low-density polyethylene, carbon black and silicon dioxide, the mass ratio is 82:10:8, the density is 1.4-1.5 g/cm ³, the tensile strength is 12MPa, and the elongation at break is 140%. The Shore hardness H _A of the microtube sheath material is 84, and the optical fiber microtube sheath can be easily torn off by hands by 1m.

The outer diameter of the 6-core optical fiber microtube is 1.2+/-0.1 mm, the equivalent circumferential diameter of the optical fiber accounts for 70-80% of the inner diameter of the microtube sheath, and the water blocking yarn accounts for 10-15% of the inner cavity surface area of the microtube sheath.

Example 2

In this example, the number of optical fiber cores of the easily-peelable dry optical fiber microtube 20 is 12.

Each microtube 20 is internally provided with 12 optical fibers 2, the colors of the optical fibers 2 are blue, orange, green, brown, gray, white, red, black, yellow, purple, powder and turquoise, the G.657A2 optical fibers are adopted as the optical fibers, the diameter of the colored optical fiber coating is 200 mu m plus or minus 10 mu m, and the optical fibers in the microtube 20 are SZ twisted.

Each microtube 20 contains 1 300D water-blocking yarn 3, the linear density of the water-blocking yarn 3 is 30000m/kg, and the performance type selection requirements are that: the tensile strength is more than or equal to 12N, the elongation at break is more than or equal to 12%, the thermal shrinkage is less than or equal to 3.5%, the expansion rate is more than or equal to 25ml/g/min, the expansion rate is more than or equal to 30ml/g, and the water content is less than or equal to 8%. In this example, the water-absorbing fiber solidified with polyacrylic acid and acrylic acid salt is mainly made of terylene or chinlon.

The wall thickness of the microtube sheath 1 is 0.15mm, the material of the microtube sheath 1 is a mixture of ethylene-alkyd ethylene copolymer and aluminum hydroxide, the mass ratio is 95:5, the density is usually 1.4-1.5 g/cm ³, the tensile strength is usually 12MPa, and the elongation at break is 140%. The Shore hardness H _A of the material of the microtube sheath 1 is 84, and the optical fiber microtube sheath 1 can be easily torn off by hands for 1m.

The outer diameter of the 12-core optical fiber microtube 20 is usually 1.3+/-0.1 mm, the equivalent circumferential diameter of the optical fiber accounts for 70-80% of the inner diameter of the microtube sheath, and the water-blocking yarn accounts for 12-18% of the inner cavity surface area of the microtube sheath.

Example 3

An easily-stripped dry optical fiber microtube 20 has 12 cores.

The color of each optical fiber 2 is blue, orange, green, brown, gray, white, red, black, yellow, purple, powder and turquoise, each optical fiber 2 adopts G.657A2 optical fibers, the diameter of the colored optical fiber coating is 250 mu m +/-10 mu m, and the optical fibers 2 adopt SZ stranding in the microtube sheath 1.

Each microtube 20 contains 1 600D water-blocking yarn 3, the density of the water-blocking yarn 3 is 15000m/kg, and the performance type selection requirements are that: the tensile strength is more than or equal to 20N, the elongation at break is more than or equal to 12%, the thermal shrinkage is less than or equal to 3.5%, the expansion rate is more than or equal to 30ml/g/min, the expansion rate is more than or equal to 40ml/g, and the water content is less than or equal to 8%. In this example, the water-absorbing fiber containing acrylic acid graft copolymer has a matrix mainly of terylene or chinlon.

The wall thickness of the microtube sheath 1 is 0.2mm, the microtube sheath 1 is made of a mixture of ethylene-methyl acrylate copolymer and ethylene-butyl acrylate copolymer and kaolin, the mass ratio is 45:45:10, the density is usually 1.4-1.5 g/cm ³, the tensile strength is usually 18MPa, and the elongation at break is 210%. The Shore hardness H _A of the microtube sheath material is 89, and the optical fiber microtube sheath 1 can be easily torn off by hands by 1m.

The outer diameter of the 12-core optical fiber microtube 20 is usually 1.5+/-0.1 mm, the equivalent circumferential diameter of the optical fiber accounts for 70-80% of the inner diameter of the microtube sheath, and the water-blocking yarn accounts for 8-16% of the inner cavity surface area of the microtube sheath.

The following table 1 lists the number and outer diameters of the various optical fibers in the class of dry fiber microtubes 20, and the preferred values for the outer diameters of the fiber microtubes.

TABLE 1

The shore hardness H _A of the microtube sheath 1 material in the easily-stripped dry optical fiber microtube 20 is not more than 90, the microtube sheath can be torn off by bare hands without using a tool, the force is small, and the optical fiber is not damaged; the minimum bending radius of the optical fiber microtube is 10mm, and the optical fiber microtube is not bent; the optical fiber microtube 20 does not contain ointment, the water-blocking material adopts water-blocking yarns, the environment is protected, and the construction is efficient and quick; the optical fiber, the water-blocking yarn and the microtube sheath in the optical fiber microtube have strong compatibility and stable physical and chemical properties of the large-length optical fiber.

Referring to fig. 2,3 and 4, the dry optical fiber microtube 20 of the present invention is applied to a microbeam cable structure to form an all-dry microbeam cable 100, which is generally used in an urban backbone network, and is generally laid by outdoor pipelines or overhead pipelines.

In a specific basic embodiment, taking the micro-tube 20 of the 6-core optical fiber 2 as an example, as shown in fig. 2, the cross-sectional structure of the all-dry micro-beam optical cable 100 includes a plurality of micro-tubes 20, a plurality of water-blocking yarns 3 and an outer jacket 30, each water-blocking yarn 3 is filled in a gap between the plurality of micro-tubes 20, and a plurality of reinforcing members 31 are embedded in the outer jacket 30. The micro-tube is the easily-stripped dry optical fiber micro-tube 20, the number of the micro-tube in one optical cable can be 3, 6, 9, 12, 15, 18, 21 or 24 or 30, and the like, and the micro-tube 20 is spirally twisted in the inner cavity of the outer sheath 30, can also be SZ twisted or S twisted according to the size and performance requirements of the optical cable, so as to form a micro-tube core 84, and is arranged in the center of the optical cable. The performance of the water-blocking yarn 3 is in accordance with or higher than that of a first part of water-blocking material for YDT 1115.2-communication cable and optical cable: water-blocking yarn, industry standard specification. The outer sheath 30 is made of polyolefin material, typically medium density polyethylene or high density polyethylene material, or low smoke halogen-free flame retardant polyolefin material. The reinforcement 31 is usually a glass fiber reinforced plastic rod (FRP for short), the FRP density is 2.05-2.15 g/cm ³, the tensile and bending strength is more than or equal to 1100MPa, the tensile and bending elastic modulus is more than or equal to 50GPa, the elongation at break is less than or equal to 4%, the water absorption is less than or equal to 0.1%, and the reinforcement has a lower thermal expansion coefficient of 5 multiplied by 10 ^-5～6×10^-5K^-1 and is stable in acid-base resistance and chemical property. In order to ensure the bonding force between the FRP and the outer sheath, a layer of organic polymer is coated on the surface of the FRP, and the main component of the FRP is ethylene acrylic acid copolymer, and the pulling force between the FRP and the outer sheath is more than or equal to 50N.

In the structure of the aforementioned base cable, a reinforcing layer 50 (see fig. 3 or 4) may be further disposed between the twisted optical fiber microtubes (the microtube core 84) and the outer sheath 30, and the reinforcing layer 50 is disposed substantially coaxially with the outer sheath 30 and the microtube core 84. The reinforcing layer 50 may be any one of aramid, glass fiber yarn or polyester yarn, or any one of aramid and water-blocking yarn, glass fiber yarn and water-blocking yarn or polyester yarn and water-blocking yarn, or a mixture thereof.

In the structure of the aforementioned base cable, a water blocking tape 40 (as shown in fig. 3 and 4) may be further disposed between the twisted optical fiber microtubes (microtube core 84) and the outer sheath 30, and the water blocking tape 40 is disposed substantially coaxially with the outer sheath 30 and the microtube core 84. The water-blocking tape 40 is usually a double-sided water-blocking tape, which is formed by sequentially compounding polyester fiber non-woven fabric, super absorbent expansion material and polyester fiber non-woven fabric, wherein the super absorbent expansion material is formed by compounding crosslinked polyacrylate expansion powder, and has the advantages of heat resistance, no acid or alkali content and stable chemical resistance; the thickness of the water-blocking tape is less than or equal to 0.25mm, the expansion rate is more than or equal to 10mm/min, the expansion height is more than or equal to 12mm, the tensile strength is more than or equal to 40N/cm, and the elongation at break is more than or equal to 12%. In other embodiments, the water-blocking tape 40 may further have a tear cord 41 (as shown in fig. 4) embedded therein, where the tear cord 41 may be an aramid or polyester yarn, and has a linear density of greater than or equal to 333tex, a tensile strength of greater than or equal to 150N, an elongation at break of greater than or equal to 12%, a softening point of greater than or equal to 238 ℃, and a melting point of greater than or equal to 265 ℃.

In the structure of the all-dry microbeam optical cable 100 as shown in fig. 4, the optical cable comprises a core layer to an outer layer, a micro tube core 84, a reinforcing layer 50, a water blocking tape 40 and an outer sheath 30 which are arranged in a substantially coaxial manner, wherein 24 micro tubes 20 are arranged in the micro tube core 84, and 5 water blocking yarns 3 are randomly filled in gaps between the micro tubes 20 and the micro tubes 20; each microtube 20 consists of 5 optical fibers 2 and 1 water-blocking yarn 3 which are stranded, and a microtube sheath 1 which is wrapped on the outer layer of the microtube; the water blocking tape 40 is embedded with 1 tear cord 41, and the outer sheath 30 is embedded with 2 stiffeners 31 in the radial direction. When the number of microtubes 20 exceeds 12, differentiation can be made by using spray printing of a different number of color patches or rings.

Example 4

An all-dry microbeam cable 100 has a fiber 2 core count of 144 cores and a structure generally as shown in fig. 4.

(1) The color of each optical fiber 2 is blue, orange, green, brown, gray and white, the G.652D optical fiber is adopted as the optical fiber, the diameter of the colored optical fiber coating is 250 mu m +/-15 mu m, and the optical fiber is SZ twisted in the micro tube.

(2) Each microtube 20 contains 1 300D water-blocking yarn 3, the linear density of the water-blocking yarn 3 is 30000m/kg, the tensile strength is more than or equal to 12N, the elongation at break is more than or equal to 12%, the thermal shrinkage rate is less than or equal to 3.5%, the expansion rate is more than or equal to 25ml/g/min, the expansion rate is more than or equal to 30ml/g, and the water content is less than or equal to 8%.

(3) The wall thickness of the microtube sheath 1 is generally between 0.1 and 0.2mm, the microtube sheath 1 is made of LSZH material, the density is generally between 1.4 and 1.5g/cm ³, the tensile strength is generally 12MPa, and the elongation at break is 140%.

(4) The outer diameter of the 6-core optical fiber microtube 20 is usually 1.2+/-0.1 mm, the equivalent circumferential diameter of the optical fiber accounts for 70-80% of the inner diameter of the microtube sheath, and the water blocking yarn accounts for 8-16% of the inner cavity surface area of the microtube sheath.

(5) Microtube 20 is twisted with spiral S within the lumen of outer sheath 30.

(6) The microtubes 20 are blue, orange, green, brown, gray, white, red, black, yellow, purple, powder, cyan, blue plus 1 black, orange plus 1 black, green plus 1 black, brown plus 1 black, gray plus 1 black, white plus 1 black, red plus 1 black, black plus 1 white, yellow plus 1 black, purple plus 1 black, pink plus 1 black, cyan plus 1 black.

(7) The reinforcing layer 50 is an aramid and a water blocking yarn.

(8) The water blocking tape 40 is a double-sided water blocking tape, the thickness of the water blocking tape is 0.2mm, the width of the water blocking tape is 30mm, the expansion rate is more than or equal to 10mm/min, the expansion height is more than or equal to 12mm, the tensile strength is more than or equal to 40N/cm, and the elongation at break is more than or equal to 12%.

(9) The tearing rope 41 is made of polyester yarn, the linear density is 444tex, the tensile strength is more than or equal to 150N, the elongation at break is more than or equal to 12%, the softening point is more than or equal to 238 ℃, and the melting point is more than or equal to 265 ℃.

(10) 2 FRP reinforcing members 31 are embedded in parallel in the outer sheath 30, and the size of the reinforcing members 31 is 2.0 + -0.1 mm.

(11) The outer sheath 30 material is a high density polyethylene material with a nominal wall thickness of 2.8mm.

(12) The overall outer diameter of the 144-core, all-dry microbeam cable 100 is nominally 16.6mm, and the fiber density in the cable cavity is 1.52F/mm ².

Example 5

An all-dry microbeam optical cable 100 has 288 cores of optical fiber cores.

(1) The color of each optical fiber 2 is blue, orange, green, brown, gray, white, red, black, yellow, purple, powder and turquoise, the G.657A2 optical fiber is adopted as the optical fiber, the diameter of the colored optical fiber coating is 200 mu m +/-10 mu m, and the optical fiber 2 is stranded in the micro tube 20.

(2) Each microtube 20 contains 1 600D water-blocking yarn 3, the density of the water-blocking yarn is 15000m/kg, the tensile strength is more than or equal to 12N, the elongation at break is more than or equal to 12%, the thermal shrinkage rate is less than or equal to 3.5%, the expansion rate is more than or equal to 25ml/g/min, the expansion rate is more than or equal to 30ml/g, and the water content is less than or equal to 8%.

(4) The outer diameter of the 12-core microtube 20 is usually 1.4+/-0.1 mm, the equivalent circumferential diameter of the optical fiber accounts for 70-80% of the inner diameter of the microbeam tube, and the water-blocking yarn accounts for 10-15% of the inner cavity surface area of the microtube sheath.

(5) Microtube 20 is twisted with spiral S within the lumen of outer sheath 30.

(7) The reinforcing layer 50 is made of glass fiber yarn and water-blocking yarn.

(8) The water blocking tape 40 is a double-sided water blocking tape, the thickness of the water blocking tape is 0.2mm, the width of the water blocking tape is 34mm, the expansion rate is more than or equal to 10mm/min, the expansion height is more than or equal to 12mm, the tensile strength is more than or equal to 40N/cm, and the elongation at break is more than or equal to 12%.

(9) The tearing rope 41 can be made of polyester yarn with the linear density of 444tex, the tensile strength of more than or equal to 150N, the elongation at break of more than or equal to 12 percent, the softening point of more than or equal to 238 ℃ and the melting point of more than or equal to 265 ℃.

(10) 2 FRP reinforcing members 31 are embedded in parallel in the outer sheath 30, and the size of the reinforcing members 31 is 1.8 + -0.1 mm.

(11) The outer sheath 30 is made of high-density polyethylene material, and the wall thickness of the outer sheath 30 is 2.6mm nominally.

(12) The overall 100 outer diameter of the 288-core all-dry microbeam cable is nominally 15.1mm, and the density of the optical fibers in the cable cavity is 3.74F/mm ².

The present invention improves upon the basic cable structure described above in that a plurality of microtubes 20 are wound and combined using a winding tape 80 to provide a twisted microtube core 84 in order to increase the optical fiber density in the interior of the cable 100 to increase the communication capacity. The wrapping band 80 may be a polyester yarn, an aramid yarn, or a polyester band or a combination thereof. The thickness of the wrap 80 is typically 0.1-0.2mm and the equivalent width is typically 0.1-2mm. Typically 8-12 microtubes 20 are assembled into a bundle of bundled microtubes 82 by the bundling tape 80, and each bundle of bundled microtubes 82 is separated by the bundling tape 80 of a different color and then twisted together to form a cable core (microtube core 84) together with the water-blocking yarn. The invention also calculates and optimizes the micro tube core 84 structure through the following optical fiber density formula, thereby effectively improving the optical fiber density and the space occupation ratio of the optical fiber 2 in the inner cavity of the sheath.

σ＝N/(π×R²) (1)

Wherein: sigma is the optical fiber density, N is the optical fiber number, and R is the optical cable inner cavity radius. The density of fibers in the cable lumen is typically 3.8-10F/mm ², which is defined as the number of fibers in the cable divided by the surface area of the cable lumen.

R＝(D+K)/2 (2)

Wherein: r is the radius of the inner cavity of the optical cable, D is the equivalent diameter of the cable core, K is a correction coefficient, and the value of K is generally 0.5-1.0mm. The radius of the inner cavity of the optical cable is defined as half of the equivalent diameter of the cable core of the optical cable after the correction coefficient is added.

D＝(M₁×N₁+D₁ ²+N₂×0.43²)^1/2 (3)

Wherein: m ₁ is the thickness of the winding belts, N ₁ is the number of the winding belts, N ₂ is the equivalent number of the water-blocking yarns, which is the bus density specification of the water-blocking yarns divided by 1420Denier, and D ₁ is the twisting equivalent diameter of the microbeam tubes in the optical cable.

D₁＝1.16×N₃ ^1/2×D₂ (4)

Wherein: n ₃ is the number of microtubules and D ₂ is the outer diameter of the microtubules.

As can be seen from the above formulas (1) to (4), the optical fiber density in the inner cavity of the optical cable of the present invention is:

For example, the conventional structures of fig. 2,3 and 4 have the following optical fiber densities in the optical cable cavity:

Wherein: the density unit of the optical fiber is F/mm ²; n is the number of optical fibers; n ₃ is the number of the dry optical fiber microtubes, and D ₂ is the outer diameter of the dry optical fiber microtubes in mm.

The utility of the present invention in increasing the fiber density of a fiber optic cable is illustrated below.

Referring to fig. 5, 6 and 7, the optical cable 100 may be configured by only including a microtube formed by combining a plurality of winding microtubes 82, 84, a plurality of water-blocking yarns 3 and an outer sheath 30, wherein the plurality of water-blocking yarns 3 are filled in a hollow space between the winding microtubes 82 and the winding microtubes 82, the winding microtubes 82 are formed by winding a plurality of microtubes 20 around the winding belts 80 and the plurality of water-blocking yarns 3 are filled in the space, and the plurality of reinforcing members 31 are embedded in the outer sheath 30. In other embodiments, the cable 100 structure may also include one or more structures similar to one or more of the water blocking tape 40, strength layer 50, or tear line 41 described above.

Example 6

An all-dry microbeam optical cable having a fiber core count 432 core and a structure substantially as shown in fig. 7.

(1) The color of each optical fiber 2 is blue, orange, green, brown, gray, white, red, black, yellow, purple, powder and turquoise, each optical fiber 2 adopts G.657A2 optical fibers, the diameter of the colored optical fiber coating is 250 mu m +/-10 mu m, and the optical fibers 2 adopt SZ stranding in the microtubes 20.

(2) Each microtube 20 contains 1 600D water-blocking yarn 3, the density of the water-blocking yarn 3 is 15000m/kg, the tensile strength is more than or equal to 20N, the elongation at break is more than or equal to 12%, the thermal shrinkage rate is less than or equal to 3.5%, the expansion rate is more than or equal to 30ml/g/min, the expansion rate is more than or equal to 40ml/g, and the water content is less than or equal to 8%.

(4) The outer diameter of the 12-core microtube 20 is usually 1.5+/-0.1 mm, the equivalent circumferential diameter of the optical fiber accounts for 70-80% of the inner diameter of the sheath of the microtube, the inner diameter of the microtube is 1.1-1.3 mm, and the equivalent diameter of the water-blocking yarn in the microtube accounts for about 0.35mm and 7-10% of the surface area of the inner cavity.

(5) Microtube 20 is twisted with spiral SZ in the lumen of outer sheath 30.

(6) The microtubes 20 are blue, orange, green, brown, gray, white, red, black, yellow, purple, pink, cyan, blue plus 1 black, orange plus 1 black, green plus 1 black, brown plus 1 black, gray plus 1 black, white plus 1 black, red plus 1 black, black plus 1 white, yellow plus 1 black, purple plus 1 black, pink plus 1 black, cyan plus 1 black, blue plus 2 black, orange plus 2 black, green plus 2 black, brown plus 2 black, gray plus 2 black, white plus 2 black, red plus 2 black, black plus 2 white, yellow plus 2 black, purple plus 2 black, pink plus 2 black, and cyan plus 2 black.

(7) The wrap 80 is a polyester yarn.

(8) The polyester yarn had a thickness of 0.1mm and the number of wrap belts 80 was 3.

(9) The reinforcing layer 50 is a water blocking yarn having a number of 26 pieces of 3000 deniers.

(10) The twisted outer diameter D ₁＝1.16×36^1/2 ×1.5=10.44 mm of the microtube, the twisted outer diameter d= (0.1×3+10.44 ²+26×3000/1420×0.43²)^1/2 =10.93 mm of the cable core, the outer diameter of the cavity is 11.83mm, the optical fiber density in the cavity is 3.93F/mm ², the optical fiber density in the cavity of the conventional optical cable is 3.28F/mm ² as shown in fig. 4, and the design improves the optical fiber density by 19.8%.

(11) The water blocking tape 40 is a double-sided water blocking tape, the thickness of the water blocking tape is 0.2mm, the width of the water blocking tape is 40mm, the expansion rate is more than or equal to 10mm/min, the expansion height is more than or equal to 12mm, the tensile strength is more than or equal to 40N/cm, and the elongation at break is more than or equal to 12%. The tearing rope 41 can be made of polyester yarn with the linear density of 444tex, the tensile strength of more than or equal to 150N, the elongation at break of more than or equal to 12 percent, the softening point of more than or equal to 238 ℃ and the melting point of more than or equal to 265 DEG C

(12) 2 FRP reinforcing members 31 are embedded in parallel in the outer sheath 30, and the size of the reinforcing members is 1.8 + -0.1 mm.

(13) The outer sheath 30 material is a high density polyethylene material with a nominal wall thickness of 2.8mm.

(14) The overall outer diameter of 432 core all-dry microbeam cable 100 is nominally 17.4mm.

Example 7

An all-dry microbeam optical cable 100 has 720 cores of optical fiber.

(1) The color of each micro tube 20 is blue, orange, green, brown, gray, white, red, black, yellow, purple, powder, and turquoise, the G.657A2 optical fiber is adopted as the optical fiber, the diameter of the colored optical fiber coating is 250 mu m +/-10 mu m, and the optical fiber is SZ twisted in the micro tube.

(2) Each microtube contains 1 600D water-blocking yarn 3, the density of the water-blocking yarn is 15000m/kg, the tensile strength is more than or equal to 20N, the elongation at break is more than or equal to 12%, the thermal shrinkage rate is less than or equal to 3.5%, the expansion rate is more than or equal to 30ml/g/min, the expansion rate is more than or equal to 40ml/g, and the water content is less than or equal to 8%.

(3) The wall thickness of the microtube sheath 1 is generally between 0.1 and 0.2mm, the material of the microbeam sheath is LSZH material, the density is generally between 1.4 and 1.5g/cm ³, the tensile strength is generally 12MPa, and the elongation at break is 140%.

(4) The outer diameter of the 12-core microtube 20 is usually 1.5+/-0.1 mm, the equivalent circumferential diameter of the optical fiber accounts for 70-80% of the inner diameter of the microbeam tube, the inner diameter of the microtube is 1.1-1.3 mm, the equivalent diameter of the water-blocking yarn in the microtube is about 0.35mm, and the equivalent diameter of the water-blocking yarn in the microtube accounts for 7-10% of the inner cavity area.

(5) Microtube 20 is twisted with spiral SZ in the lumen of outer sheath 30.

(7) The wrap 80 is a polyester yarn.

(8) The polyester yarn had a thickness of 0.1mm and the number of wrap strips 80 was 5.

(9) The reinforcing layer 50 is a water blocking yarn having a number of 42 pieces of 3000 deniers.

(10) Microtube stranded outer diameter D ₁＝1.16×60^1/2 x 1.5=13.48 mm, cable core stranded outer diameter d= (0.1 x 5+13.48 ²+42×3000/1420×0.43²)^1/2 =14.09 mm, inner cavity outer diameter 15.09mm, optical fiber density in inner cavity 4.03F/mm ², optical fiber density in inner cavity of conventional optical cable shown in fig. 4 is 3.59F/mm ², optical fiber density is improved by 12.2%.

(11) The water blocking tape 40 is a double-sided water blocking tape, the thickness of the water blocking tape is 0.2mm, the width of the water blocking tape is 40mm, the expansion rate is more than or equal to 10mm/min, the expansion height is more than or equal to 12mm, the tensile strength is more than or equal to 40N/cm, and the elongation at break is more than or equal to 12%.

(12) 2 FRP reinforcing members 31 are embedded in parallel in the outer sheath 30, and the size of the reinforcing members is 2.0 + -0.1 mm.

(13) The outer sheath 30 material is a high density polyethylene material with a sheath wall thickness of nominally 3.0mm.

(14) The overall outer diameter of 720-core all-dry microbeam cable 100 is nominally 21.1mm.

Example 8

An all-dry microbeam optical cable 100 has 720 cores of optical fiber.

(1) The color of each micro tube 20 is blue, orange, green, brown, gray, white, red, black, yellow, purple, powder, and turquoise, the G.657A2 optical fiber is adopted as the optical fiber, the diameter of the colored optical fiber coating is 200 mu m + -10 mu m, and the optical fiber is stranded in the micro tube.

(2) Each microtube 20 contains 1 300D water-blocking yarn 3, the density of the water-blocking yarn is 30000m/kg, the tensile strength is more than or equal to 20N, the elongation at break is more than or equal to 12%, the thermal shrinkage rate is less than or equal to 3.5%, the expansion rate is more than or equal to 30ml/g/min, the expansion rate is more than or equal to 40ml/g, and the water content is less than or equal to 8%.

(4) The outer diameter of the 12-core microtube 20 is usually 1.3+/-0.1 mm, the equivalent circumferential diameter of the optical fiber accounts for 70-80% of the inner diameter of the sheath of the microtube, the inner diameter of the microtube is 0.9-1.1 mm, and the equivalent diameter of the water-blocking yarn in the microtube accounts for about 0.25mm and 5-8% of the inner cavity area.

(5) Microtube 20 is twisted with spiral SZ in the lumen of the outer sheath.

(7) The wrap 80 is a polyester strap.

(8) The thickness of the polyester yarn is 0.1mm, and the number of the winding belts is 5.

(9) The reinforcing layer 50 is a water blocking yarn having a number of 30 pieces of 3000 deniers.

(10) Microtube stranded outer diameter D ₁＝1.16×60^1/2 x 1.3=11.68 mm, cable core stranded outer diameter d= (0.1 x 5+11. ²+30×3000/1420×0.43²)^1/2 =12.19 mm, inner cavity outer diameter 12.69mm, optical fiber density in inner cavity 5.69F/mm ², optical fiber density in inner cavity 4.56F/mm ² of conventional optical cable as shown in fig. 4, optical fiber density is improved by 24.8%.

(13) The outer sheath 30 material is a high density polyethylene material with a nominal wall thickness of 2.6mm.

(14) The overall outer diameter of 720-core all-dry microbeam cable 100 is nominally 17.9mm.

The wound and bundled all-dry microbeam optical cable is filled with no grease, is environment-friendly and pollution-free, does not need grease cleaning during construction, and is efficient and quick; the dry water-blocking material has good compatibility with the optical fiber, and the performance of the optical fiber is not affected after long-term coexistence; the dry water-blocking material has stable performance along with temperature change, and the optical fiber transmission characteristic does not change along with temperature change; the dry water-blocking material occupies less than 20% of the inner diameter surface area of the micro-pipe, and has no influence on the sheath performance of the micro-pipe for a long time; after the binding tape is used for binding and combining a plurality of microbeam tubes, the optical fiber density and the space occupation ratio of the optical fiber in the inner cavity of the sheath can be effectively improved.

The foregoing embodiments are merely for illustrating the technical solution of the embodiment of the present invention, but not for limiting the same, although the embodiment of the present invention has been described in detail with reference to the foregoing preferred embodiments, it will be understood by those skilled in the art that modifications and equivalent substitutions may be made to the technical solution of the embodiment of the present invention without departing from the spirit and scope of the technical solution of the embodiment of the present invention.

Claims

1. The utility model provides a full dry type microbeam optical cable, includes the microtube core and cladding at the oversheath of the periphery of microtube core and a plurality of reinforcement in embedding oversheath, its characterized in that: the microtubule core comprises a plurality of winding microtubules and a plurality of water-blocking yarns, and the water-blocking yarns are filled in gaps between the winding microtubules; the winding and bundling microtubes comprise winding and bundling belts, a plurality of dry optical fiber microtubes wrapped by the winding and bundling belts and a plurality of water-blocking yarns, each dry optical fiber microtube consists of a microtube sheath, the water-blocking yarns wrapped by the microtube sheath and optical fibers, and the optical fiber density in an optical cable inner cavity is as follows:

Wherein: the density unit of the optical fiber is F/mm ²; n is the number of optical fibers; k is a correction coefficient, and the value is 0.5-1.0mm; m ₁ is the thickness of the winding belts, and N ₁ is the number of the winding belts; n ₂ is the equivalent number of water blocking yarns; n ₃ is the number of the dry optical fiber microtubes, and D ₂ is the outer diameter of the dry optical fiber microtubes;

The number of optical fibers of each dry optical fiber microtube ranges from 4 to 24, the thickness of the winding and bundling belt ranges from 0.1mm to 0.2mm, and the outer diameter of the dry optical fiber microtube ranges from 0.8mm to 2.3mm.

2. The all-dry microbeam optical cable of claim 1, wherein: the density of the optical fibers in the inner cavity of the optical cable is 3.8-10F/mm ².

3. The all-dry microbeam optical cable of claim 1, wherein: the ratio of the equivalent circumferential diameters of a plurality of optical fibers in the dry optical fiber microtube in the inner cavity of the microtube sheath is less than 90% and more than or equal to 70%, and the water blocking yarn accounts for 20% or less of the surface area of the inner cavity of the microtube sheath.

4. A full dry microbeam optical cable as in claim 3, characterized in that: the equivalent circumferential diameters of a plurality of optical fibers in the dry optical fiber microtube are between 70% and 80% of the inner cavity of the sheath of the microtube.

5. The all-dry microbeam optical cable of claim 1, wherein: the material of the microtube sheath comprises an olefin polymer and an inorganic filler, wherein the inorganic filler accounts for 0.1% -20% of the total mass of all components of the microtube sheath; the olefin polymer comprises a first olefin polymer or an ethylene/propylene copolymer with other monomers, wherein the first olefin polymer comprises one of linear low density polyethylene, poly-4-methyl-1-pentene, or an ethylene propylene copolymer; wherein the ethylene/propylene and other monomer copolymer comprises one or more of ethylene-alkyd ethylene copolymer, ethylene-methyl acrylate copolymer and ethylene-butyl acrylate copolymer; the inorganic filler comprises hydroxide, hydrous oxide, metal salt or a mixture thereof, or carbon black, silicon dioxide, kaolin, clay or a mixture thereof; the thickness of the microtube sheath is 0.1-0.2mm.

6. The all-dry microbeam optical cable of claim 1, wherein: the microtube core and the outer sheath are coaxially provided with a reinforcing layer, and the reinforcing layer is made of any one of aramid fiber, glass fiber yarn or polyester yarn or a combination of one or more of water blocking yarn and aramid fiber, glass fiber yarn or polyester yarn.

7. The all-dry microbeam optical cable of claim 1, wherein: the microtube core with still include the water blocking tape of coaxial setting between the oversheath, the water blocking tape is two-sided water blocking tape.

8. The all-dry microbeam optical cable of claim 7, wherein: the water-blocking tape also comprises a plurality of embedded tearing ropes, and the tearing ropes are made of aramid or polyester yarns.

9. The all-dry microbeam optical cable of claim 1, wherein: the material of the outer sheath is polyolefin material; the reinforcing piece is a glass fiber reinforced plastic rod with the density of 2.05-2.15 g/cm ³.

10. The all-dry microbeam optical cable of claim 1, wherein: the water-blocking yarn of each structural layer arranged in the micro-pipe core comprises water-absorbing fibers which can prevent water powder from falling off in the production process of the micro-pipe core, wherein the water-absorbing fibers contain acrylic acid, polyacrylic acid, acrylic acid salt or modified substances thereof or mixtures thereof.