High-temperature-resistant non-metal sleeve insulation optical fiber unit

Abstract

The invention discloses a high-temperature-resistant non-metal sleeve insulation optical fiber unit, and relates to the technical field of special optical cable manufacturing. The cable comprises a cable body, the cable body comprises a fiber core, a buffer layer, an insulating layer and a sheath, and the fiber core, the buffer layer, the insulating layer and the sheath are sequentially distributed from inside to outside; the high-temperature-resistant optical fiber has an all-nonmetal insulation structure, can fundamentally avoid the problems of electromagnetic induction and electrochemical corrosion, is free of electromagnetic interference, prolongs the design life, has excellent high-temperature-resistant performance, and ensures that the optical fiber unit continuously works for a long time in a high-temperature environment through the composite design of multiple layers of high-temperature-resistant materials of the fiber core, the buffer layer, the insulation layer and the sheath; the optical fiber has the advantages of simple structure, stable and reliable performance, light weight and convenience in installation, can effectively buffer thermal stress of different materials at high temperature, ensures long-term mechanical strength and optical stability of the optical fiber at high temperature, and has high safety and reliability.

Description

Technical Field

[0001] This invention relates to the field of special optical cable manufacturing technology, specifically a high-temperature resistant non-metallic insulated optical fiber unit. Background Technology

[0002] As the core carrier of optical signal transmission, optical fiber units have been widely used in various communication and sensing systems. However, in extreme industrial environments such as metallurgy, chemical industry, nuclear power, and underground pipe corridors, there are harsh conditions such as continuous high temperature, high humidity, chemical corrosion and strong electromagnetic interference, which pose a severe challenge to the reliability of traditional optical fiber units.

[0003] Traditional optical fiber units have the following drawbacks: First, ordinary non-metallic optical cables often use polyvinyl chloride, polyethylene, or ordinary polyamide materials for their sheaths. Their long-term operating temperature is usually no more than 90°C. In high-temperature environments above 200°C, they will age and melt, leading to loss of mechanical properties and interruption of signal transmission. Second, metallic sheathed optical cables, such as stainless steel tube optical fiber units, although they have good temperature resistance and mechanical protection, are heavy, have poor flexibility, are inconvenient to lay, and the metal material itself is susceptible to electrochemical corrosion, which drastically reduces its lifespan in corrosive environments. More importantly, the metal sheath can induce current in strong electromagnetic environments, which not only interferes with signal transmission but may also cause safety problems. To address these issues, the inventors have proposed a high-temperature resistant non-metallic sheathed insulated optical fiber unit to solve these problems. Summary of the Invention

[0004] To address the issues of poor reliability and short lifespan of traditional optical cables under high temperature, high humidity, and strong electromagnetic environments, the present invention aims to provide a high-temperature resistant non-metallic insulated optical fiber unit.

[0005] To solve the above technical problems, the present invention adopts the following technical solution: a high-temperature resistant non-metallic insulated optical fiber unit, comprising a cable body, wherein the cable body comprises a fiber core, a buffer layer, an insulation layer and a sheath, and the fiber core, buffer layer, insulation layer and sheath are distributed sequentially from the inside to the outside.

[0006] Preferably, the buffer layer is a composite material of polyimide and ceramicized silicone rubber, with a nano-ceramic protective layer on its surface. The thickness of the nano-ceramic protective layer is 100-200 nm. The fiber core is a fluorine-doped quartz glass optical fiber, which has excellent bending resistance and is suitable for laying in narrow spaces. Its attenuation coefficient is ≤0.5dB / km, and its numerical aperture is 0.22. The thickness of the polyimide coating in the buffer layer is 5-10μm. The nano-ceramic protective layer is prepared by the sol-gel method. The buffer layer, together with the internal ceramicized silicone rubber, can effectively isolate the fiber core from high temperature and moisture damage. The insulation layer is composed of mica tape and polytetrafluoroethylene film wrapped alternately. The overlap rate of the mica tape and polytetrafluoroethylene film is ≥50%. The thickness of the mica tape is 0.1mm, and the thickness of the polytetrafluoroethylene film is 0.05mm. Its breakdown voltage is ≥20kV, and its dielectric constant is ≤2.2.

[0007] Preferably, the sheath is made of aramid fiber-reinforced polyetheretherketone (PEEK) material, with an aramid fiber volume fraction of 15%-25%. The sheath is UV-cured to achieve a surface hardness ≥80 Shore D. The sheath is manufactured using an extrusion molding process, specifically by extruding PEEK material reinforced with aramid fibers woven at a 45° angle. The molding temperature is 380-400℃. After cooling, the surface hardness is improved by UV curing, resulting in a tensile strength ≥800 MPa and a bending radius ≤5 times the cable diameter. A marking layer is fixedly connected to the outer surface of the sheath. This marking layer has high-temperature resistance and is printed with product specifications, production batch numbers, and other information using high-temperature resistant ink on the outer surface of the sheath.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention features a fully non-metallic insulating structure, which fundamentally avoids electromagnetic induction and electrochemical corrosion problems, eliminates electromagnetic interference, extends design life, and has excellent high-temperature resistance. Through the multi-layer high-temperature resistant material composite design of fiber core, buffer layer, insulation layer and sheath, it ensures that the optical fiber unit can work continuously in high-temperature environments with stable and reliable performance.

[0009] 2. This invention has the advantages of being lightweight and easy to install. The sheath is made of aramid fiber reinforced PEEK, which significantly reduces the weight compared to stainless steel sheathed optical cables of the same specifications. It also has excellent tensile strength and bending performance, with a small minimum bending radius, making it easy to lay and install. Furthermore, through a unique nano-ceramic composite buffer layer, it can effectively buffer the thermal stress of different materials at high temperatures and match the thermal expansion coefficient of the fiber core, ensuring the long-term mechanical strength and optical stability of the optical fiber at high temperatures.

[0010] 3. This invention has high safety and reliability. The insulation layer and sheath are made of flame-retardant and fire-resistant materials, which enables the optical fiber unit to be used in extreme environments with extremely high safety requirements, such as nuclear power plants and tunnels. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0013] Figure 2 This is an enlarged view of point A in the present invention.

[0014] In the diagram: 1. Cable body; 2. Fiber core; 3. Buffer layer; 4. Insulation layer; 5. Sheath; 6. Identification layer. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Example: Figure 1-2 As shown, the present invention provides a high-temperature resistant non-metallic insulated optical fiber unit, including a cable body 1. The cable body 1 includes a fiber core 2, a buffer layer 3, an insulation layer 4, and a sheath 5, and the fiber core 2, buffer layer 3, insulation layer 4, and sheath 5 are distributed sequentially from the inside to the outside.

[0017] The buffer layer 3 is a composite material of polyimide and ceramicized silicone rubber, and a nano-ceramic protective layer is provided on its surface. The thickness of the nano-ceramic protective layer is 100-200 nm.

[0018] By adopting the above technical solution, the fiber core 2 is a fluorine-doped quartz glass optical fiber, which has excellent bending resistance and is suitable for laying in narrow spaces. Its attenuation coefficient is ≤0.5dB / km and its numerical aperture is 0.22. The thickness of the polyimide coating in the buffer layer 3 is 5-10μm. The nano-ceramic protective layer is prepared by the sol-gel method. The buffer layer 3, which is composed of the nano-ceramic protective layer and the internal ceramicized silicone rubber, can effectively isolate the fiber core 2 from the damage caused by high temperature and moisture.

[0019] The insulation layer 4 is composed of mica tape and polytetrafluoroethylene film wrapped alternately, and the overlap rate of the mica tape and polytetrafluoroethylene film is ≥50%.

[0020] By adopting the above technical solution, the thickness of the mica tape is 0.1 mm, the thickness of the polytetrafluoroethylene film is 0.05 mm, its breakdown voltage is ≥20 kV, and its dielectric constant is ≤2.2.

[0021] Sheath 5 is made of polyetheretherketone material reinforced with aramid fiber, and the volume fraction of aramid fiber is 15%-25%. Sheath 5 is treated with ultraviolet light and has a surface hardness ≥80 Shore D.

[0022] By adopting the above technical solution, the sheath 5 adopts an extrusion molding process, specifically it can be extruded from polyetheretherketone material reinforced by aramid fibers cross-woven at a 45° angle, with a molding temperature of 380-400℃. After cooling, it is treated with ultraviolet curing to improve surface hardness, with a tensile strength ≥800 MPa and a bending radius ≤5 times the cable diameter.

[0023] The outer surface of the sheath 5 is fixedly connected with an identification layer 6, which has high temperature resistance.

[0024] By adopting the above technical solution, a high-temperature resistant marking layer 6 with product specifications, production batch number and other information is printed on the outer surface of the sheath 5 using high-temperature resistant ink.

[0025] Working principle: When using this invention, a polyimide coating with a thickness of about 8 μm is first coated on the outer surface of the fiber core 2 to form a primary buffer and insulation. Then, a nano-ceramic protective layer with a thickness of about 150 nm is prepared on the coating by the sol-gel method. This layer, together with the internal ceramicized silicone rubber, forms a buffer layer 3, which can effectively isolate the fiber core 2 from the damage caused by high temperature and moisture. The insulating layer 4 outside the buffer layer 3 is made of mica tape with a thickness of 0.1 mm and polytetrafluoroethylene film with a thickness of 0.05 mm, which are alternately and tightly wrapped with an overlap rate of 55%, providing extremely high electrical insulation strength and thermal insulation performance. The outermost layer is the sheath 5, which is made of polyetheretherketone and incorporates aramid fibers woven at a 45° angle as reinforcing ribs at a volume fraction of about 20%. The sheath 5 is extruded and coated at a temperature of 390° using an extruder. After water cooling and shaping, it undergoes UV curing surface treatment to achieve a surface hardness of over 80 Shore D, giving it wear resistance and scratch resistance. Furthermore, a high-temperature resistant labeling layer 6, containing product specifications, production batch number, and other information, is printed on the outer surface of the sheath 5 using high-temperature resistant ink.

[0026] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0027] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A high temperature resistant non-metallic jacketed optical fiber unit comprising a cable body (1) characterized in that: The cable body (1) comprises a core (2), a buffer layer (3), an insulation layer (4) and a sheath (5), and the core (2), the buffer layer (3), the insulation layer (4) and the sheath (5) are sequentially distributed from inside to outside.

2. A high temperature resistant non-metallic jacketed optical fiber unit as defined in claim 1, wherein, The buffer layer (3) is a polyimide and ceramicized silicone rubber composite material, and a nano ceramic protective layer is arranged on the surface of the buffer layer (3), and the thickness of the nano ceramic protective layer is 100-200 nm.

3. A high temperature resistant non-metallic jacketed optical fiber unit as defined in claim 1, wherein, The insulation layer (4) is composed of mica tape and polytetrafluoroethylene film which are alternately wrapped.

4. A high temperature resistant non-metallic jacketed optical fiber unit as defined in claim 3, wherein, The wrapping overlap rate of the mica tape and the polytetrafluoroethylene film is greater than or equal to 50%.

5. A high temperature resistant non-metallic jacketed optical fiber unit as defined in claim 1, wherein, The sheath (5) is aramid fiber reinforced polyether ether ketone material, and the volume fraction of aramid fiber is 15%-25%.

6. A high temperature resistant non-metallic jacketed optical fiber unit as defined in claim 1, wherein, The sheath (5) is treated by ultraviolet curing, and the surface hardness is greater than or equal to 80 Shore D.

7. A high temperature resistant non-metallic jacketed optical fiber unit as defined in claim 1, wherein, An identification layer (6) is fixedly connected to the outer surface of the sheath (5), and the identification layer (6) has high temperature resistance.

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