A new type of fully dry fiber optic ribbon high flame-retardant and fire-resistant slotted core optical cable

Abstract

The present invention provides a new type of fully dry fiber ribbon high flame-retardant and fire-resistant slotted core optical cable, which enhances the flame-retardant and fire-resistant performance of the optical cable and reduces the smoke density during the fire of the optical cable. It is a high flame-retardant, small cable diameter, and high-density optical fiber cable, which can be applied to places with dense population and high safety level requirements. It includes a dry fiber structure located at the central position. The dry fiber structure specifically includes a sleeve and a number of water-blocking fiber ribbons. The outer peripheral surface of the sleeve is annularly provided with a composite tape layer. A number of water-blocking fiber ribbons forming an integral body are arranged in the inner cavity of the sleeve. The number of cores of each water-blocking fiber ribbon is 2 - 24 cores. The outer ring of the composite tape layer is coated with an outer sheath. Four parallelly arranged fiberglass reinforced plastics (FRP) are inlaid in the outer sheath. The water-blocking fiber ribbons are divided into two layers. The inner layer is cured with acrylic resin, and the outer layer is cured with a polymer organic solution. The outer layer of the water-blocking fiber ribbon is coated with a water-blocking coating.

Description

Technical Field

[0001] The present invention relates to the technical field of cable structures, and particularly to a new type of fully dry fiber ribbon high flame-retardant and fire-resistant slotted tube optical cable. Background Art

[0002] Existing fiber ribbon slotted tube flame-retardant optical cable products adopt a semi-dry water-blocking structure, that is, a combination of conventional-sized fiber ribbons + fiber filling paste inside the sleeve and dry water-blocking tape outside the sleeve to meet the longitudinal water-blocking performance of the optical cable. The flame-retardant performance of the product is designed to meet the single-fiber-optic-cable vertical combustion standard and the layer-bundle combustion standard of the GB / T and IEC series.

[0003] In the fields of data centers, FTTH, and metropolitan area network construction, an optical cable with high flame retardancy, small cable diameter, and high fiber density is required. Traditional fiber paste-filled optical cables cannot meet such performance requirements, so it is necessary to explore a new type of optical cable structure. Summary of the Invention

[0004] In view of the above problems, the present invention provides a new type of fully dry fiber ribbon high flame-retardant and fire-resistant slotted tube optical cable, which increases the flame-retardant and fire-resistant performance of the optical cable, reduces the smoke density during a fire, and is a high flame-retardant, small cable diameter, and high fiber density optical fiber cable that can be applied to places with a high population density and high safety level requirements.

[0005] A new type of fully dry fiber ribbon high flame-retardant and fire-resistant slotted tube optical cable, characterized in that: it includes a dry fiber structure located at the central position, and the dry fiber structure specifically includes a sleeve and a plurality of water-blocking fiber ribbons. The outer peripheral surface of the sleeve is annularly provided with a composite tape layer. A plurality of water-blocking fiber ribbons forming a whole are arranged in the inner cavity of the sleeve. The core number of each water-blocking fiber ribbon is 2-24 cores. The outer ring of the composite tape layer is covered with an outer sheath, and four parallelly arranged glass fiber reinforced plastics (FRP) are inlaid in the outer sheath. The water-blocking fiber ribbons are divided into two layers, the inner layer is cured with an acrylic resin, the outer layer is cured with a polymer organic solution, and the outer layer of the water-blocking fiber ribbon is coated with a water-blocking coating.

[0006] It is further characterized in that:

[0007] The material of the sleeve is specifically polybutylene terephthalate (PBT), polypropylene (PP), or a double-layer co-extrusion of PBT and PP;

[0008] The composite tape layer is specifically composed of an inner high-expansion water-blocking tape and an outer corrugated steel-plastic composite tape for armoring;

[0009] A plurality of strands of glass fiber yarns or aramid yarns are also wound between the sleeve and the inner high-expansion water-blocking tape as auxiliary load-bearing elements;

[0010] The composite tape layer is specifically an inner layer of a longitudinally wrapped double-sided reinforced mica tape and an outer layer of a multi-strand water-blocking glass fiber yarn armor layer, and the multi-strand water-blocking glass fiber yarn armor layer is synchronously wrapped around the outer circumference of the double-sided reinforced mica tape;

[0011] The composite tape layer is specifically composed of an inner layer of longitudinally wrapped double-sided reinforced mica tape and an outer layer of longitudinally wrapped corrugated steel-plastic composite tape armor;

[0012] The water-blocking optical fiber ribbon specifically contains an optical fiber of 200 μm or 180 μm. The outer layer of the water-blocking optical fiber ribbon is coated with a certain thickness of liquid coating and cured under a UV light source, so that the surface of the optical fiber ribbon is crystallized to form a film-like molecular crystal, and then a layer of high-expansion water-blocking material for water absorption and waterproofing is coated to form a water-blocking layer. The thickness of the water-blocking coating is 15 to 35 μm, so as to achieve dry water-blocking performance of the optical fiber ribbon.

[0013] The thickness of the double-sided reinforced mica tape is specifically 0.14mm-0.25mm, with a deviation of ±0.02mm, and the content of double-sided reinforced mica must be ≥55%;

[0014] Four parallel arranged glass fiber reinforced plastics (FRP) play the main load-bearing role, wherein the size of the glass fiber reinforced plastic is specifically 1.4mm-1.8mm, the wall thickness between the inner edge of the glass fiber reinforced plastic and the outer layer of corrugated steel-plastic composite tape or glass fiber yarn armor layer is required to be ≥0.5mm, the wall thickness between the outer edge of the glass fiber reinforced plastic and the sheath is required to be ≥1.0mm, and the nominal total thickness of the outer sheath is required to be ≥2.9mm;

[0015] A tear rope is also built into the outer sheath, and the tear rope is used for rapid stripping of the outer sheath.

[0016] After adopting the present invention, the small-size new water-blocking optical fiber ribbon + fully dry casing structure + steel-plastic composite tape / glass fiber yarn / double-sided reinforced mica tape armor layer + high flame retardant outer sheath has a large fiber core density, a smaller outer diameter, less combustion smoke release, and excellent flame retardant and smoke density performance compared to the traditional conventional size optical fiber ribbon + oil-filled casing structure. The flame retardant performance of the optical cable of this invention can meet the GB / T 18380.33 and IEC60332-3-22A class bundle combustion level, the EU CPR Cca S1a / d1 / a1 flame retardant level, and the IEC smoke density standard, and can meet the light transmittance ≥ 85%. The fire resistance of Scheme 2 and Scheme 3 can meet the fire resistance level of GB / T19216 and IEC60331-25. Under 750°C, the optical fiber optical power change of the optical cable is less than 3dB after 90 minutes of flame combustion. It increases the flame retardant and fire resistance of the optical cable and reduces the smoke density when the optical cable catches fire. It is a highly flame retardant, small-diameter, high-density optical fiber cable, which can be used in densely populated places with high safety requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Cross-sectional structure schematic diagram of the first specific embodiment of the present invention;

[0018] Figure 2 Cross-sectional structure schematic diagram of the second specific embodiment of the present invention;

[0019] Figure 3 Cross-sectional structure schematic diagram of the third specific embodiment of the present invention;

[0020] The names corresponding to the serial numbers in the figure are as follows:

[0021] Dry optical fiber structure 1, sleeve 2, water-blocking optical fiber ribbon 3, composite tape layer 4, outer sheath 5, glass fiber reinforced plastic 6, inner high-expansion water-blocking tape 7, outer corrugated steel-plastic composite tape 8, double-sided reinforced mica tape 9, water-blocking glass fiber yarn armor layer 10, tearing cord 11. Specific embodiments

[0022] A new type of fully dry optical fiber ribbon high-flame-retardant and fire-resistant slotted core optical cable, as shown in Figures 1 - 3 : It includes a dry optical fiber structure 1 located at the central position. The dry optical fiber structure 1 specifically includes a sleeve 2 and several water-blocking optical fiber ribbons 3. The outer peripheral surface of the sleeve 2 is circumferentially provided with a composite tape layer 4. Several water-blocking optical fiber ribbons 3 forming an integral body are arranged in the inner cavity of the sleeve 2. The core number of each water-blocking optical fiber ribbon 3 is 2-24 cores. The outer ring of the composite tape layer 4 is coated with an outer sheath 5. Four parallelly arranged glass fiber reinforced plastics 6 (FRP) are embedded in the outer sheath 5. The water-blocking optical fiber ribbons 3 are divided into two layers, the inner layer is cured with acrylic resin, and the outer layer is cured with a polymer organic solution. The outer layer of the water-blocking optical fiber ribbon 3 is coated with a water-blocking coating of 15um - 35um.

[0023] The material of the sleeve 2 is specifically polybutylene terephthalate (PBT), polypropylene (PP), or a double-layer co-extrusion of PBT and PP.

[0024] Specific embodiment one, as shown in Figure 1 : The composite tape layer 4 is specifically armored by an inner high-expansion water-blocking tape 7 and an outer corrugated steel-plastic composite tape 8;

[0025] Multiple strands of glass fiber yarn or aramid yarn 12 (aramid yarn in the figure) are also wound between the sleeve 2 and the inner high-expansion water-blocking tape 7 as an auxiliary load-bearing element.

[0026] Specific embodiment two, as shown in Figure 2 : The composite tape layer 4 is specifically an inner longitudinally wrapped double-sided reinforced mica tape 9 and an outer multi-strand water-blocking glass fiber yarn armor layer 10. The multi-strand water-blocking glass fiber yarn armor layer 10 is synchronously wound around the outer circumference of the double-sided reinforced mica tape 9.

[0027] Specific embodiment three, see Figure 3 The composite tape layer body is composed of an inner longitudinal double-sided reinforced mica tape 9 and an outer longitudinal corrugated steel-plastic composite tape 8.

[0028] In a specific embodiment, the water-blocking optical fiber ribbon 3 contains an optical fiber of 200 μm or 180 μm. The outer layer of the water-blocking optical fiber ribbon 3 is coated with a certain thickness of liquid coating and cured under a UV light source, so that the surface of the optical fiber ribbon is crystallized to form a film-like molecular crystal, which is a high-expansion water-blocking material for water absorption and waterproofing, and forms a water-blocking layer. The thickness of the water-blocking layer is 15 to 35 μm, so as to achieve dry water-blocking performance of the optical fiber ribbon.

[0029] The thickness of the double-sided reinforced mica tape 9 is specifically 0.14 mm to 0.25 mm, with a deviation of ±0.02 mm, and the content of the double-sided reinforced mica must be ≥55%;

[0030] Four parallel arranged glass fiber reinforced plastics 6 (FRP) play the main role of bearing the load, wherein the size of the glass fiber reinforced plastic 6 is specifically 1.4mm-1.8mm, the wall thickness between the inner edge of the glass fiber reinforced plastic 6 and the outer layer of the corrugated steel-plastic composite tape 8 or the water-blocking glass fiber yarn armor layer 10 is required to be ≥0.5mm, the wall thickness between the outer edge of the glass fiber reinforced plastic 6 and the sheath is required to be ≥1.0mm, and the nominal total thickness of the outer sheath is required to be ≥2.9mm;

[0031] A tear cord 11 is also built into the outer sheath 5 , and the tear cord 11 is used for rapid peeling of the outer sheath 5 .

[0032] The principle is as follows: small-size new water-blocking optical fiber ribbon + fully dry casing structure + steel-plastic composite tape / glass fiber yarn / double-sided reinforced mica tape armor layer + high flame retardant outer sheath. Compared with the traditional conventional size optical fiber ribbon + oil-filled casing structure, the optical cable core density is large, the outer diameter is smaller, the combustion smoke release is small, and the flame retardant and smoke density performance are excellent. The flame retardant performance of the optical cable can meet the GB / T 18380.33 and IEC60332-3-22A bundled combustion level, the EU CPR Cca S1a / d1 / a1 flame retardant level, and the IEC smoke density standard, and can meet the light transmittance ≥ 85%. The fire resistance performance of Scheme 2 and Scheme 3 can meet the fire resistance level of GB / T 19216 and IEC60331-25. At 750°C, after 90 minutes of flame combustion, the optical power change of the optical cable fiber is less than 3dB.

[0033] The innovation of the present invention lies in:

[0034] 1. Structural innovation: a. In order to achieve high flame retardancy, fire resistance and low smoke emission performance, while meeting the characteristics of high-density optical fiber and small cable diameter, structural innovation has been carried out, and the traditional ribbon oil-filled casing structure has been transformed into a fully dry optical fiber ribbon casing structure. The outer diameter of the product optical cable has been reduced by more than 25%, and the flame retardancy and smoke density performance has been doubled, which improves the flame retardancy of the product from a structural perspective; b. The outer side of the cable core casing is reinforced with double-sided reinforced mica tape + multiple strands of glass fiber yarn, or double-sided reinforced mica tape + steel-plastic composite tape to form a flame retardant and fire-resistant armor layer. At the same time, four parallel FRPs are embedded in the outer sheath to increase the tension, stiffness and flame retardancy of the optical cable.

[0035] 2. Process innovation: a. New water-blocking optical fiber ribbon and ribbon molding process. After the optical fiber is cured once with acrylic resin, it is then cured twice with a special organic solution. Finally, a layer of film-like molecules is formed on the surface of the optical fiber ribbon, which expands rapidly when exposed to water to meet the water-blocking performance of the optical cable cross section. b. The sheathing adopts the vacuum sizing outer diameter forming process. The optical fiber ribbon is released through the twisting cage with stable tension, and passes through the optical fiber ribbon collection guide wheel inlet mold and outlet mold. The water-blocking tape and the optical fiber ribbon are longitudinally wrapped through the guide mold to enter the vacuum sizing and then formed into a sleeve. The water-blocking tape is released by an active tape release device; reasonable mold ratio ensures smooth extrusion of the sleeve, polybutylene terephthalate (PBT), optical fiber ribbon and water-blocking tape pass through the vacuum sizing and sizing inlet mold together to complete the preforming process, and a reasonably configured vacuum device mold is used to ensure the sealing state of the sleeve gap at the sizing mold inlet to prevent air from entering. After the sleeve is basically formed by vacuum sizing and vacuuming, it passes through the sizing outlet mold and enters the multi-section hot water tank, traction wheel, cold water tank in turn, and finally goes on the coil to complete the winding. This process forms a certain amount of optical fiber excess length through reasonable control.

[0036] 3. Material innovation: a. This invention selects small-sized optical fiber, 200um or 180um optical fiber, and uses polymer organic liquid coating UV curing to form film-like molecular crystals on the surface of the optical fiber ribbon, and finally coats a layer of high-expansion water-blocking material for water absorption and waterproofing. The thickness of the water-blocking coating is 10-45um; b. The sheath material uses low-smoke halogen-free ceramic polyolefin, etc., which has high flame retardancy and high crack resistance (oxygen index ≥ 42%). Ceramic polyolefin is a halogen-free high-oxygen index sheath material. When it is burned at high temperature, it is easy to ceramicize and form a dense protective layer, thereby blocking flames and heat transfer, and protecting the optical fiber from high-temperature damage. c. This invention uses double-sided reinforced mica tape, which does not contain crystalline water and has a melting point of more than 1300°C. When the burning flame temperature exceeds 1000°C, it can also ensure that the optical cable core is not damaged by fire, and has high safety performance. The fire-resistant mica tape can preferably be made of muscovite or phlogopite, and the materials should be evenly bonded without defects such as bubbles, pinholes, and mica paper breakage. Glass cloth reinforcement is used on both sides, and glass cloth drawing is not allowed.

[0037] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0038] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A new type of fully dry optical fiber ribbon highly flame retardant and fire resistant bundle tube optical cable, Features: It includes a dry optical fiber structure located at a central position, the dry optical fiber structure specifically includes a sleeve, a plurality of water-blocking optical fiber ribbons, the outer circumferential surface of the sleeve is annularly covered with a composite tape layer, a plurality of integrally formed water-blocking optical fiber ribbons are arranged in the inner cavity of the sleeve, each water-blocking optical fiber ribbon has 2-24 cores, the outer annular surface of the composite tape layer is covered with an outer sheath, four parallelly arranged glass fiber reinforced plastics are embedded in the outer sheath, the water-blocking optical fiber ribbon is divided into two layers, the inner layer is cured by acrylic resin, the outer layer is cured by polymer organic solution, and the outer layer of the water-blocking optical fiber ribbon is coated with a water-blocking coating; The composite tape layer is specifically composed of an inner longitudinally wrapped double-sided reinforced mica tape and an outer multi-strand water-blocking glass fiber yarn armor layer, and the multi-strand water-blocking glass fiber yarn armor layer is synchronously wrapped around the outer circumference of the double-sided reinforced mica tape; or the composite tape layer is specifically composed of an inner longitudinally wrapped double-sided reinforced mica tape and an outer longitudinally wrapped corrugated steel-plastic composite tape armor; The water-blocking optical fiber ribbon specifically contains an optical fiber of 200 μm or 180 μm. The outer layer of the water-blocking optical fiber ribbon is coated with a certain thickness of liquid coating and cured under a UV light source, so that the surface of the optical fiber ribbon is crystallized to form a film-like molecular crystal, and then a layer of high-expansion water-blocking material for water absorption and waterproofing is coated to form a water-blocking layer. The thickness of the water-blocking coating is 15 μm to 35 μm. The thickness of the double-sided reinforced mica tape is specifically 0.14mm-0.25mm, with a deviation of ±0.02mm, and the content of double-sided reinforced mica must be ≥55%; Four parallel arranged glass fiber reinforced plastics play the main role in bearing the load, wherein the size of the glass fiber reinforced plastic is specifically 1.4mm~1.8mm, the wall thickness between the inner edge of the glass fiber reinforced plastic and the outer layer of corrugated steel-plastic composite tape or glass fiber yarn armor layer is required to be ≥0.5mm, the wall thickness between the outer edge of the glass fiber reinforced plastic and the sheath is required to be ≥1.0mm, and the nominal total thickness of the outer protection is required to be ≥2.9mm.

2. A novel fully dry optical fiber ribbon highly flame retardant and fire resistant bundle tube optical cable as claimed in claim 1, Features: The material of the sleeve is specifically polybutylene terephthalate, polypropylene or double-layer co-extrusion of PBT and PP.

3. A novel fully dry optical fiber ribbon highly flame retardant and fire resistant bundle tube optical cable as claimed in claim 1, Features: A tear cord is also built into the outer sheath.

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