High-performance flame-retardant optical cable

Abstract

The utility model discloses a high-performance flame-retardant optical cable, which relates to the technical field of optical cable manufacturing and comprises a central reinforcing member extending along the axial direction. The flame-retardant cushion layer is coated on the periphery of the central reinforcing piece; the optical unit layer is arranged outside the flame-retardant cushion layer and comprises a plurality of optical transmission units which are distributed in the circumferential direction of the flame-retardant cushion layer; a water-blocking isolation layer wrapping the outside of the optical unit layer; a plurality of water-blocking media filled between the optical unit layer and the water-blocking isolation layer; and the flame-retardant outer sheath is coated outside the water-blocking isolating layer. The high-performance flame-retardant optical cable provided by the utility model has the advantages of high flame retardance, multi-layer waterproof protection and environmental stress resistance.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of optical cable manufacturing, specifically to a high performance flame retardant optical cable. BACKGROUND

[0002] With the rapid development of information technology, optical cable is more and more widely used in the field of communication, data transmission, etc. The performance of optical cable directly affects the stability and safety of information transmission. In the production of optical cable, the flame retardant property is an important index. The traditional optical cable gradually exposes the following defects in flame retardancy, waterproofness and mechanical stability, etc.

[0003] 1. Insufficient flame retardant property: the existing optical cable usually uses polyethylene (PE) or polyvinyl chloride (PVC) as the outer sheath material, and its oxygen index is relatively low (usually ≤28%), which is easy to produce melt drops and release toxic gases during combustion, resulting in the spread of fire. Especially in a closed space (such as a tunnel or a computer room), the flame retardant property of the traditional sheath cannot meet the safety requirements.

[0004] 2. Single waterproof structure: conventional optical cable usually relies on optical fiber grease filling or single water-blocking tape to achieve waterproofness, but problems such as grease drying and water seepage at the joint of water-blocking tape are easy to occur during long-term use, which causes water to invade the inside of the optical cable along the axial or radial direction, resulting in optical fiber transmission loss or even breakage.

[0005] 3. Structural failure in high-temperature and friction environment: there is a lack of high-temperature-resistant and low-friction isolation layer between the central reinforcing member and the optical unit layer, which causes structural deformation due to the difference in thermal expansion coefficient between metal and non-metal materials in high-temperature environment (such as the initial stage of fire or high-temperature area), or aggravates the micro-bending loss of optical fiber due to friction during dynamic bending.

[0006] 4. Insufficient weather resistance: when the optical cable is exposed to the outdoors for a long time, ultraviolet radiation, acid and alkali corrosion, and sand abrasion can easily cause the sheath to age and crack, shortening the service life. In the prior art, the modified sheath by adding an anti-aging agent still cannot meet the harsh environmental requirements in terms of chemical stability.

[0007] Polytetrafluoroethylene (PTFE) is a material with excellent chemical stability and high-temperature resistance. Therefore, the skilled person in the art proposes a high-performance flame-retardant optical cable. CONTENT OF THE UTILITY MODEL

[0008] In view of the deficiencies of the prior art, the utility model provides a high-performance flame-retardant optical cable with high flame retardancy, multi-layer waterproof protection and environmental stress resistance.

[0009] To achieve the above purpose, the utility model realizes the following technical scheme:

[0010] A high-performance flame-retardant optical cable comprises:

[0011] a center reinforcing member extending in an axial direction;

[0012] a fireproof pad layer wrapped around the outer periphery of the center reinforcing member;

[0013] a light unit layer disposed outside the fireproof pad layer, the light unit layer comprising a plurality of light transmission units distributed circumferentially around the fireproof pad layer;

[0014] a water-blocking isolation layer wrapped outside the light unit layer;

[0015] a plurality of water-blocking media filled between the light unit layer and the water-blocking isolation layer;

[0016] a fireproof outer sheath wrapped outside the water-blocking isolation layer.

[0017] Further, the light transmission unit comprises a loose tube, at least one optical fiber is arranged in the loose tube, and optical fiber grease is filled between the optical fiber and the inner wall of the loose tube.

[0018] Further, the loose tube is made of polybutylene terephthalate material, and the wall thickness is 0.3-0.6mm.

[0019] Further, the center reinforcing member is a metal material or a non-metal reinforcing member.

[0020] Further, the fireproof pad layer and the fireproof outer sheath are both made of polytetrafluoroethylene material.

[0021] Further, the water-blocking media are composed of a plurality of spiral-wound water-blocking yarns, and the water-blocking yarns are super-absorbent fiber yarns or swelling water-blocking yarns.

[0022] Further, the water-blocking isolation layer is a water-blocking tape.

[0023] Further, the fireproof outer sheath has a wall thickness of 1.2-2.0mm and a smooth surface.

[0024] Further, the surface of the fireproof outer sheath is subjected to plasma treatment to form a dense fluorinated layer, and the thickness of the dense fluorinated layer is 40-100μm.

[0025] Compared with the prior art, the high-performance fireproof optical cable has the following advantages:

[0026] 1. The polytetrafluoroethylene fireproof pad layer is wrapped around the center reinforcing member, and the excellent fireproof performance of the polytetrafluoroethylene fireproof pad layer is utilized to prevent heat from being transmitted to the inside under high temperature or friction environment, reduce the friction loss of the light unit layer and the center member, and improve the dynamic bending performance.

[0027] 2. The polytetrafluoroethylene flame-retardant outer sheath serves as the outermost layer of protection, and its flame-retardant property can inhibit flame spread and avoid the emission of toxic and harmful substances during the combustion of traditional polyethylene sheaths. The "double-layer flame-retardant barrier" formed by the flame-retardant pad layer and the flame-retardant outer sheath further enhances the flame-retardant performance and mechanical strength of the optical cable, significantly improves the safety of the optical cable in fire scenarios, and does not produce a large amount of toxic smoke and corrosive gas during combustion, meeting environmental protection requirements.

[0028] 3. The water-blocking tape and the water-blocking yarn form a water-blocking barrier, and the bidirectional water-blocking structure formed by radial wrapping and axial filling prevents water from spreading along the axial direction of the optical cable or penetrating radially, and is particularly suitable for use in humid or waterlogged environments.

[0029] 4. The surface of the polytetrafluoroethylene flame-retardant outer sheath is treated by plasma to form a dense fluorinated layer, which can resist ultraviolet aging, acid and alkali corrosion, and sand and dust abrasion, thereby prolonging the service life of the optical cable in outdoor harsh environments. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 FIG. 1 is a cross-sectional view of a high-performance flame-retardant optical cable.

[0031] In the figure: 1, optical fiber; 2, optical fiber grease; 3, loose tube; 4, central reinforcing member; 5, flame-retardant pad layer; 6, water-blocking medium; 7, water-blocking isolation layer; 8, flame-retardant outer sheath. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0033] Please refer to Figure 1 The present application provides a technical solution: a high-performance flame-retardant optical cable, comprising:

[0034] A central reinforcing member 4 extending in the axial direction, the central reinforcing member 4 being a metal material or a non-metal reinforcing member;

[0035] A flame-retardant pad layer 5 wrapped around the outer periphery of the central reinforcing member 4;

[0036] An optical unit layer provided outside the flame-retardant pad layer 5, the optical unit layer comprising a plurality of optical transmission units distributed circumferentially around the central reinforcing member;

[0037] A water-blocking isolation layer 7 wrapped outside the optical unit layer;

[0038] A plurality of water-blocking media 6 filled between the optical unit layer and the water-blocking tape layer 7;

[0039] An outer polytetrafluoroethylene sheath 8 is extruded over the water-blocking tape layer 7.

[0040] The flame-retardant cushion layer 5 and the flame-retardant outer sheath 8 are both made of polytetrafluoroethylene.

[0041] The high-performance flame-retardant optical cable has the following comprehensive advantages through the multi-layer functional structure design: through the synergistic effect of the central strength member 4 and the flame-retardant cushion layer 5, the longitudinal tensile strength of the optical cable is ensured, and the external impact energy is absorbed through the elastic deformation of the flame-retardant cushion layer 5, the flame-retardant cushion layer 5 is wrapped outside the strength member, and the flame-retardant cushion layer 5 has excellent flame-retardant performance, the high oxygen index characteristic prevents heat from being transmitted to the inside in a high-temperature or friction environment, reduces the friction loss between the optical unit layer and the central member, improves the dynamic bending performance, and forms a flame-retardant defense line. As the outermost protective layer, the polytetrafluoroethylene outer sheath has flame-retardant performance, can inhibit flame spread, and avoids the emission of toxic and harmful substances when the traditional polyethylene sheath burns; and the flame-retardant cushion layer 5 forms an "internal and external double-layer flame-retardant barrier", further enhances the flame-retardant performance and mechanical strength of the optical cable, and significantly improves the safety of the optical cable in a fire scene, so that a large amount of toxic smoke and corrosive gas is not generated during burning, and environmental protection requirements are met.

[0042] The optical transmission unit includes a loose tube 3, a plurality of optical fibers 1 are arranged in the loose tube 3, and optical fiber ointment 2 is filled between the optical fibers 1 and the inner wall of the loose tube 3. The optical fiber ointment 2 in the loose tube 3 plays a buffering role and can absorb and disperse external forces such as bending, vibration and impact that the optical fiber receives during cable laying and use. The loose tube 3 is made of polybutylene terephthalate material, and the wall thickness is 0.3-0.6 mm. The PBT loose tube is designed by optimizing the tube wall thickness. When the wall thickness is 0.3 mm, the conventional scene requirements are met, and when the wall thickness is 0.6 mm, the extreme working conditions are adapted, and the gradient configuration of performance and cost is realized.

[0043] The water-blocking medium 6 is composed of a plurality of helically wound water-blocking yarns, and the helically wound water-blocking yarns form a three-dimensional water-blocking network. Compared with the traditional linear filling method, the spiral structure keeps the water-blocking medium uniformly distributed when bending and laying. The water-blocking yarn is super-absorbent fiber yarn or expanded water-blocking yarn.

[0044] The water-blocking isolation layer 7 is a water-blocking tape composed of two layers of non-woven fabric sandwiching expanded water-blocking powder. This structure can not only realize the water-blocking function, but also ensure the flexibility and electrical performance of the material.

[0045] A water-blocking barrier is formed by the water-blocking tape and the water-blocking yarn, and a bidirectional water-blocking structure of radial wrapping and axial filling prevents water from diffusing along the axial direction of the optical cable or penetrating radially, and is especially suitable for humid or water-immersed environments.

[0046] The flame-retardant outer sheath 8 has a wall thickness of 1.2-2.0 mm, which meets the requirements of mechanical protection and light weight, avoids the increase of the weight and the decrease of the flexibility of the optical cable caused by over-thickness, has a smooth surface with a small friction coefficient, reduces the friction resistance with other objects during the laying of the optical cable, facilitates the construction, and reduces the damage risk to the internal structure of the optical cable.

[0047] The surface of the flame-retardant outer sheath 8 is subjected to plasma treatment to form a dense fluorinated layer with a thickness of 40-100 μm. The dense fluorinated layer is formed on the surface of the sheath by plasma treatment, has higher chemical stability than untreated polytetrafluoroethylene, can resist ultraviolet aging, acid and alkali corrosion, and sand and dust abrasion, prolongs the service life of the optical cable in outdoor harsh environments, maintains stable performance in the range of-60℃ to 260℃, and avoids the problems of high-temperature melting or low-temperature embrittlement.

Claims

1. A high performance flame retardant optical fiber cable characterized by, The application relates to a flame-retardant optical cable, which comprises the following parts: a central reinforcing part (4) extending in the axial direction; a flame-retardant cushion layer (5) wrapped around the periphery of the central reinforcing part (4); a light unit layer arranged outside the flame-retardant cushion layer (5), wherein the light unit layer comprises a plurality of light transmission units distributed in the circumferential direction of the flame-retardant cushion layer (5); a water-blocking isolation layer (7) wrapped outside the light unit layer; a plurality of water-blocking media (6) filled between the light unit layer and the water-blocking isolation layer (7); a flame-retardant outer sheath (8) wrapped outside the water-blocking isolation layer (7).

2. The high performance flame retardant optical cable of claim 1, wherein, The light transmission unit comprises a loose tube (3), at least one optical fiber (1) is arranged in the loose tube (3), and optical fiber grease (2) is filled between the optical fiber (1) and the inner wall of the loose tube (3).

3. The high performance flame retardant optical cable of claim 2, wherein, The loose tube (3) is made of polybutylene terephthalate material, and the wall thickness is 0.3-0.6 mm.

4. The high performance flame retardant optical cable of claim 1, wherein, The central reinforcing part (4) is a metal material or a non-metal reinforcing part.

5. The high performance flame retardant optical cable of claim 1, wherein, The flame-retardant cushion layer (5) and the flame-retardant outer sheath (8) are both made of polytetrafluoroethylene material.

6. The high performance flame retardant optical cable of claim 1, wherein, The water-blocking media (6) are composed of a plurality of spiral-wound water-blocking yarns, wherein the water-blocking yarns are super-absorbent fiber yarns or swelling water-blocking yarns.

7. The high performance flame retardant optical cable of claim 1, wherein, The water-blocking isolation layer (7) is a water-blocking tape.

8. The high performance flame retardant optical cable of claim 5, wherein, The wall thickness of the flame-retardant outer sheath (8) is 1.2-2.0 mm, and the surface is smooth.

9. The high performance flame retardant optical cable of claim 8, wherein, The surface of the flame-retardant outer sheath (8) is subjected to plasma treatment to form a dense fluorinated layer, and the thickness of the dense fluorinated layer is 40-100 mu m.

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