Multi-layer protection cable resistant to extreme environment

Abstract

The invention discloses a multi-layer protection cable resistant to an extreme environment, and belongs to the technical field of cables. The cable is of a seven-layer composite structure design and sequentially comprises a conductor, an insulating layer, a shielding layer, a buffer layer, a waterproof layer, a heat insulation layer and a protective outer layer from inside to outside, and the conductor is made of high-purity oxygen-free copper; the insulating layer is made of a polyimide material and has high temperature resistance, low temperature resistance and excellent insulating property; the shielding layer is composed of a tinned copper wire woven mesh and a high-permeability permalloy foil, and electromagnetic interference is effectively shielded; the buffer layer is made of an elastic rubber material to relieve mechanical stress; the waterproof layer adopts a nanoscale fluorosilicone resin coating and has excellent waterproof performance; the heat insulation layer is made of ceramic fibers and aerogel, and efficient heat insulation is provided; and the protective outer layer is made of a high-strength and corrosion-resistant polyether-ether-ketone (PEEK) material. The cable has excellent high temperature resistance, low temperature resistance, corrosion resistance and electromagnetic interference resistance, is suitable for extreme environments, and ensures stable transmission of electric power and signals under extreme conditions.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of cables, and particularly relates to a multi-layer protective cable resistant to extreme environments. BACKGROUND

[0002] In today's industry, energy, communication and other fields, the application of cables is extremely wide. However, in many extreme environments, such as high-temperature metallurgical and chemical production sites, low-temperature polar scientific exploration and cold storage environments, strong-corrosion marine platforms and chemical laboratories, and high-electromagnetic interference substations and communication base stations, ordinary cables are difficult to maintain stable operation. These extreme environments pose severe challenges to the performance of cables, including temperature resistance, corrosion resistance, electromagnetic interference resistance, and mechanical strength In high-temperature environments, the insulation material of ordinary cables is prone to aging and softening, leading to a decrease in insulation performance and causing short-circuit faults. For example, in metallurgical and chemical production sites, the temperature can be as high as 300℃ or above, and the insulation material of ordinary cables such as PVC or PE will rapidly age and lose insulation performance at this temperature. In low-temperature environments, the flexibility of cables decreases, and they are prone to brittle fracture, affecting power transmission and signal transmission. For example, in polar scientific exploration or cold storage environments, the temperature can be as low as -60℃, and the insulation material of ordinary cables will become brittle and hard, easily breaking. In strong-corrosion environments, the metal conductor and outer sheath of cables will be gradually corroded, shortening their service life. For example, in marine platforms or chemical laboratories, cables are exposed to salt mist or chemically corrosive gases, and the metal parts will rapidly corrode. In high-electromagnetic interference environments, the signal transmission of ordinary cables is prone to interference, causing data loss or errors. For example, near substations or communication base stations, the electromagnetic interference strength can be as high as 100 dB or above, and the shielding performance of ordinary cables is insufficient to resist such interference.

[0003] With the rapid development of industries, aerospace, deep-sea exploration and other fields, higher requirements are placed on the extreme environment resistance of cables. There is an urgent need in the market for a cable with excellent temperature resistance, corrosion resistance and electromagnetic shielding performance to meet the demand for long-term stable operation in extreme environments. SUMMARY

[0004] The purpose of the present application is to provide a multi-layer protective cable resistant to extreme environments, which addresses the lack of stability of existing cables in extreme environments. Through the synergistic optimization of material selection and structural design, the cable achieves integrated protection against high temperature, low temperature, corrosion, electromagnetic interference and mechanical cushioning.

[0005] To solve the above technical problems, the purpose of the present application is achieved as follows: The multi-layer protective cable resistant to extreme environment comprises, from inside to outside, the following structures: a conductor layer: high-purity oxygen-free copper or silver-plated copper wire is adopted, purity ≥ 99.99%, single conductor diameter is 0.1-5.0 mm; an insulating layer: polyimide material is adopted, and 5%-8% nano-aluminum oxide is added; a shielding layer: tinned copper wire braided mesh and high-permeability permalloy foil are included, braided density ≥ 85%, alloy foil thickness is 0.05-0.2 mm, double-layer lap joint rate ≥ 30%, electromagnetic shielding effectiveness in the frequency band of 30 MHz-1 GHz is ≥ 90 dB; a buffer layer: hydrogenated nitrile rubber or silicone rubber is adopted, Shore hardness is 40-60A, thickness is 1.0-3.0 mm, after foaming treatment, a closed-cell structure is formed, foaming rate is 20%-40%, dynamic compression permanent deformation is ≤ 15%; a waterproof layer: nano-scale fluorosilicone resin coating is adopted, thickness is 50-200 μm, surface contact angle is > 150°, and IP68 level waterproof test is passed; a heat insulation layer: ceramic fiber and aerogel composite material are adopted, thickness is 2.0-5.0 mm, thermal conductivity is ≤ 0.02 W / (m·K); a protective outer layer: polyether ether ketone material is adopted, thickness is 1.0-3.0 mm, 15% carbon fiber is added for reinforcement.

[0006] As a preferred scheme of the above scheme and on the basis of the above scheme: the conductor layer adopts a layered stranding process, stranding pitch is 10-12 times of the conductor diameter, surface roughness Ra is ≤ 0.8 μm.

[0007] As a preferred scheme of the above scheme and on the basis of the above scheme: conductive glue is coated between the tinned copper wire braided mesh and the permalloy foil of the shielding layer, realizing full-circumferential equipotential connection.

[0008] As a preferred scheme of the above scheme and on the basis of the above scheme: aramid fiber mesh is embedded in the buffer layer, mesh density is 10×10 meshes.

[0009] As a preferred scheme of the above scheme and on the basis of the above scheme: 2% carbon nanotubes are added to the waterproof layer to construct a conductive path to avoid static charge accumulation.

[0010] As a preferred scheme of the above scheme and on the basis of the above scheme: an aluminum foil reflective film is coated on the outer layer of the heat insulation layer, thickness is 0.1 mm, reflectivity is ≥ 95%.

[0011] As a preferred scheme of the above scheme and on the basis of the above scheme: the surface of the protective outer layer is subjected to laser etching anti-slip lines, depth is 0.2-0.5 mm, friction coefficient is ≥ 0.8.

[0012] The technical effects of the present application are as follows: 1. Wide temperature range adaptation: the insulation layer and the protective outer layer cooperatively realize a temperature resistance range of -200℃ to +350℃, and the cable can be stably operated in a high-temperature metallurgical environment and a polar low-temperature environment for a long time. 2. Strong corrosion resistance: the fluorosilicon resin waterproof layer and the PEEK outer layer form double protection, and the cable has excellent salt mist resistance and chemical corrosion resistance, and is suitable for marine platforms and chemical scenes. 3. High-efficiency electromagnetic shielding: the composite structure of the tinned copper wire braid and the permalloy foil has a shielding effectiveness of ≥90 dB in the frequency band of 30 MHz-1 GHz, and can resist high electromagnetic interference environments such as transformer substations. 4. Mechanical buffering and wear resistance: the closed-cell foaming buffer layer can relieve mechanical stress, and the dynamic compression permanent set is ≤15%; the PEEK outer layer is designed with anti-slip lines to improve the friction coefficient and avoid slipping during installation and use. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a schematic diagram of the overall structure of the present application.

[0014] 1-conductor, 2-insulation layer, 3-shielding layer, 4-buffer layer, 5-waterproof layer, 6-thermal insulation layer, 7-protective outer layer. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiments will be described clearly and completely below in combination with the drawings in the embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments given, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0016] In the description of the present application, it should be understood that the terms "upper", "lower" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0017] In the description of the present application, the terms "first", "second" and the like are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. EMBODIMENTS

[0018] The present application discloses a multi-layer protective cable resistant to extreme environments, which is suitable for high-temperature and anti-interference cables in the application scenario of an aero-engine cabin: Preparation process (1) Conductor layer preparation Material selection: High purity oxygen-free copper wire (OFC, purity 99.996%) with a diameter of 0.5 mm was selected. The impurity content was detected by ICP-MS: Fe ≤ 0.001%, Pb ≤ 0.0005%.

[0019] Stranding process: 1+6+12 layer stranding was adopted (1 core, 6 inner layers, and 12 outer layers), a planetary stranding machine (speed 300 r / min) was used, and the stranding pitch was strictly controlled at 5 mm (10 times the diameter of the conductor). After stranding, the internal stress was eliminated by a continuous annealing furnace (400°C nitrogen protection, 2h holding), and the wire was collected after cooling to room temperature.

[0020] Surface treatment: drawn through a precision diamond drawing die (precision ± 0.001 mm) to ensure a surface roughness Ra = 0.6 μm, and monitored online using a laser profilometer.

[0021] (2) Insulating layer coating Material configuration: Polyimide (PI) resin (type Kapton® HN) and nano-alumina (particle size 50 nm, purity 99.9%) were mixed in a mass ratio of 94:6, and a uniform slurry was prepared by a high-speed shearing dispersion machine (speed 10000 r / min, dispersion time 30 min).

[0022] Coating process: Three-layer co-extrusion casting method was adopted, the mold temperature was 380°C, the extrusion speed was 1.2 m / min, and the coating thickness was 0.8 mm (real-time adjustment by online laser thickness gauge). After coating, it was cured in stages: 120°C x 1h (pre-curing) → 250°C x 2h (imidization) → 350°C x 1h (complete curing), to ensure a gel content > 95%.

[0023] (3) Shielding layer composite Braided mesh preparation: Tinned copper wire with a diameter of 0.1 mm (tin layer thickness 3 μm, adhesion ≥ 5 N / cm) was selected, braided on a 16-spindle braiding machine at a braiding density of 86%, with a braiding angle of 45° and a tension control of 5 ± 0.5 N to avoid copper wire stretching and deformation.

[0024] Palladium foil composite: 0.1 mm thick palladium foil (Ni80Fe20, permeability μ ≥ 80000) was used, which was bonded to the braided mesh by hot pressing process (temperature 120°C, pressure 0.5 MPa), with a lap width of 3 mm (lap rate 30%), and silver-based conductive adhesive was applied at the lap joint (resistivity < 1 x 10⁻ 4 Ω·cm).

[0025] (4) Buffer layer forming Rubber mixing: hydrogenated nitrile rubber (HNBR, acrylonitrile content 36%) was mixed with blowing agent AC (azodicarbonamide) at a mass ratio of 100:5, 1.5 parts of vulcanizing agent DCP was added, and mixing was carried out on an open mill at 80°C for 15 min to ensure uniform dispersion (no agglomeration was observed by electron microscopy).

[0026] Foam molding: The mixed rubber was extruded and wrapped outside the shielding layer (thickness 2.0 mm), and foaming was carried out in a flat vulcanizing machine at 160°C for 20 min, with a foaming rate of 30% (density was measured by drainage method: 0.7 g / cm³), and a 10x10 mesh aramid fiber grid (single filament strength 2.8 GPa) was embedded, and the grid and rubber were chemically bonded through isocyanate coupling agent.

[0027] (5) Waterproof layer coating Fluorosilicone resin coating: A nano fluorosilicone resin (model DS-601) with a solid content of 60% was used, 2% multi-walled carbon nanotubes (aspect ratio 50, diameter 10 nm) were added, and a 100 μm coating was formed by electrostatic spraying process (voltage 60 kV, flow rate 80 mL / min), and then cured in a UV curing oven (wavelength 365 nm, energy 800 mJ / cm²) for 30 s.

[0028] Performance test: After coating, contact angle measurement (155°) and waterproof test (1 m water immersion for 72 h, insulation resistance change rate <5%) were carried out.

[0029] (6) Thermal insulation layer coating Core material preparation: Ceramic fibers (diameter 3 μm, length 50 mm) and aerogel (density 0.12 g / cm³) were mixed at a volume ratio of 3:1, 0.5% silane coupling agent was added, and a 3.0 mm thick roll was formed by wet forming, and the thermal conductivity was 0.018 W / (m·K) (Hot Disk method).

[0030] Aluminum foil composite: A 0.1 mm thick pure aluminum foil (purity 99.9%) was coated on the outer layer of the thermal insulation layer, and tight fitting was achieved by hot pressing (temperature 150°C, pressure 0.3 MPa), and the surface of the aluminum foil was mirror polished (reflectivity 96%, spectrophotometer test).

[0031] (7) Protective outer layer extrusion Material formula: Polyether ether ketone (PEEK, model 450G) was added with 15% chopped carbon fiber (length 0.2 mm, diameter 7 μm), and melt blending was carried out in a double screw extruder at 380°C, screw speed 300 r / min, to ensure uniform dispersion of carbon fiber (no agglomeration was observed by SEM).

[0032] Extrusion and surface treatment: PEEK composite material is extruded outside the thermal insulation layer (thickness 2.0 mm), and a 0.3 mm deep rhombus anti-skid pattern (pitch 2 mm) is processed on the surface by using a laser etching machine (wavelength 1064 nm), and the friction coefficient test (dry state) reaches 0.9 (ASTM D1894 standard).

[0033] Performance verification High temperature resistance test: placed in a 300°C constant temperature oven for 1000h, insulation resistance retention rate > 90% (initial value 10¹ 7 Ω·cm), and the breakdown voltage has no obvious decay (35kV / mm).

[0034] Anti-interference test: in a 1GHz electromagnetic environment (field strength 100dBμV / m), the signal transmission error rate is <10⁻ 8 (10⁻ 4 ⁻ for ordinary cable).

[0035] Bending performance: according to IEC 60228 standard, 1000 times of reciprocating bending is carried out at a bending radius of 30mm (6D, D=5mm), and the conductor fracture strength retention rate is >95%. Example

[0036] The application discloses a multi-layer protective cable resistant to extreme environment, aiming at a high-pressure corrosion-resistant cable for deep-sea exploration: Key process optimization (1) Conductor layer enhancement Silver-plated copper wire with a diameter of 1.0mm (silver layer thickness 5μm, conductivity 103%IACS) is selected, and 1+6+12+18 four-layer twisting (total cross-sectional area 16mm²) is adopted, with a twisting pitch of 10mm (10 times the diameter of the conductor), and the elongation at break after annealing is ≥30%.

[0037] (2) Thickening design of waterproof layer The thickness of fluorosilicone resin coating is increased to 200μm, and a "spraying-curing-recoating" two-coating process is adopted to ensure that the surface contact angle reaches 160°, and the water permeation pressure is ≥150kPa (more than 100kPa required by IP68 standard).

[0038] (3) Strengthening of protective outer layer The carbon fiber addition amount in PEEK material is increased to 20%, and the tensile strength reaches 250MPa (Instron universal testing machine test, rate 5mm / min), and the corrosion rate in seawater corrosion test (3.5%NaCl solution, 80°C immersion for 1000h) is 0.005mm / year (calculated by weight loss method).

[0039] Extreme environment test Deep sea high pressure test: placed in a simulated 1000m water depth high pressure chamber (pressure 10MPa) for 72h, the cable outer diameter change rate <1%, and the insulation resistance has no attenuation.

[0040] Low temperature toughness test: bending test at-40℃ (bending radius 6D), no crack is generated, and the buffer layer compression permanent deformation is 12% (GB / T 7759 standard). Embodiment

[0041] The application discloses a multilayer protective cable resistant to extreme environment, aiming at the cable in strong corrosive environment of a chemical industrial park: In order to verify the corrosion resistance of the protective outer layer material, a comparative test is added: Control group: a conventional PVC outer layer cable (thickness 2.0mm) is used.

[0042] The application group: the PEEK+15% carbon fiber outer layer of embodiment 1 is used.

[0043] Test condition: 5% H2SO4 solution immersion for 1000h (60℃).

[0044] Result: the corrosion rate of the control group is 0.2mm / year (complete failure), and the corrosion rate of the application group is 0.008mm / year (performance retention rate >90%).

[0045] Through the detailed process parameters and performance verification of the above embodiments, the technical scheme of the application can be stably reproduced, and all performance indicators are better than the prior art, and can fully meet the use requirements in extreme environment The above embodiments are only preferred embodiments of the application, and do not limit the protection scope of the application, so: all equivalent changes made according to the structure, shape, principle of the application should be covered in the protection scope of the application.

Claims

1. Multilayer protective cable resistant to extreme environments, characterized by, From inside to outside, it includes the following structures: conductor layer: high-purity oxygen-free copper or silver-plated copper wire is used, purity ≥ 99.99%, single conductor diameter is 0.1-5.0 mm; Insulating layer: polyimide material is used, and 5%-8% nano alumina is added; Shielding layer: including tinned copper wire braided mesh and high permeability permalloy foil, braided density ≥ 85%, alloy foil thickness is 0.05-0.2 mm, double-layer lap rate ≥ 30%, electromagnetic shielding effectiveness in 30 MHz-1 GHz frequency band ≥ 90 dB; Buffer layer: hydrogenated nitrile rubber or silicone rubber is used, shore hardness is 40-60A, thickness is 1.0-3.0 mm, after foaming treatment, closed cell structure is formed, foaming rate is 20%-40%, dynamic compression permanent set ≤ 15%; Waterproof layer: nanoscale fluorosilicone resin coating is used, thickness is 50-200 μm, surface contact angle > 150°, and IP68 level waterproof test is passed; Thermal insulation layer: ceramic fiber and aerogel composite material are used, thickness is 2.0-5.0 mm, thermal conductivity ≤ 0.02 W / (m·K); Protective outer layer: polyether ether ketone material is used, thickness is 1.0-3.0 mm, 15% carbon fiber is added for reinforcement.

2. The extreme environment resistant multi-layered shielded electrical cable of claim 1, wherein: The conductor layer uses a layered twisting process, the twisting pitch is 10-12 times the conductor diameter, and the surface roughness Ra ≤ 0.8 μm.

3. The extreme environment resistant multi-layered shielded electrical cable of claim 1, wherein: The tinned copper wire braided mesh of the shielding layer is coated with conductive adhesive between the permalloy foil to realize full circumferential equipotential connection.

4. The extreme environment resistant multi-layered shielded electrical cable of claim 1, wherein: The buffer layer is embedded with aramid fiber grid, the grid density is 10×10 mesh.

5. The extreme environment resistant multi-layer protected cable of claim 1, wherein: The waterproof layer adds 2% carbon nanotubes to construct a conductive path to avoid static charge accumulation.

6. The extreme environment resistant multi-layer protected cable of claim 1, wherein: The outer layer of the thermal insulation layer is coated with aluminum foil reflective film, thickness is 0.1 mm, reflectivity ≥ 95%.

7. The extreme environment resistant multi-layer protected cable of claim 1, wherein: The surface of the protective outer layer is laser etched with anti-slip lines, depth is 0.2-0.5 mm, friction coefficient ≥ 0.8.

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