High-reliability mobile cable for high-temperature and acidic environment and processing technology thereof

Abstract

This invention relates to the field of cable technology, and in particular to a high-reliability mobile cable for use in high-temperature acidic environments and its processing technology. From the inside out, it comprises a bipolar protective conductor, a thermally conductive and insulating synergistic layer, a shielding-buffering-sensing integrated structure, a sealing-reinforcement synergistic core layer, and a gradient composite sheath layer. This invention employs a full-layer synergistic protection structure consisting of a bipolar protective conductor, a thermally conductive and insulating synergistic layer, a shielding-buffering-sensing integrated structure, a sealing-reinforcement synergistic core layer, and a gradient composite sheath layer. Each layer has compatible materials and matched coefficients of thermal expansion, with no structural gaps. Combined with a multi-corrosion-resistant and high-temperature-resistant material system including a titanium-based composite coating, nano-yttrium oxide stabilizer, plasma-modified fluororubber outer layer, and a superhydrophobic composite sealant, it completely blocks the penetration channels of acidic media, significantly improving corrosion and high-temperature resistance. This extends the cable's service life to over 3.5 years under conditions of 280℃ and 98% concentrated sulfuric acid, resulting in a significantly extended service life.

Description

Technical Field

[0001] This invention relates to the field of cable technology, and in particular to a high-reliability mobile cable for use in high-temperature acidic environments and its processing technology. Background Technology

[0002] In industrial settings such as metallurgy, chemical engineering, and electroplating, mobile cables, as core components for power and signal transmission, must withstand multiple harsh conditions, including dual corrosion from high temperatures and strong acids, high-frequency dynamic bending fatigue, and mechanical stress impact. This places integrated demands on the cables' corrosion resistance, high-temperature resistance, fatigue resistance, structural sealing, and condition sensing capabilities. While existing mobile cables have attempted to improve performance through single-material modification or structural thickening, their independent design of each structural layer and lack of a collaborative protection mechanism still result in numerous technical defects, making them unsuitable for actual operating conditions. The sheath, insulation, and conductor protection layers operate independently, lacking a layered design for corrosion resistance and high temperature resistance. The single fluororubber / polyurethane sheath has insufficient temperature resistance, and the tin / nickel-plated conductor coating has poor adhesion to the insulation layer. Under dynamic bending, the coating is prone to peeling off and the insulation layer is prone to cracking. Acidic media can easily penetrate layer by layer through the structural gaps, causing conductor corrosion and conductivity degradation. Under strong acidic conditions at 80℃, the service life generally does not exceed 6 months. The cable core lacks a sealing-reinforcement-buffering collaborative structure. The gap filling material has poor hydrophobic sealing performance, making it easy for acidic media to penetrate. Furthermore, the mechanical stress generated by dynamic bending cannot be gradually dissipated through each structural layer and directly acts on the insulation and shielding layers, easily causing insulation rupture, shielding layer breakage, and cable short circuit faults. The shielding and buffering structures are designed separately. The buffer layer only has a simple shock absorption effect and cannot provide support and protection for the shielding layer. Under dynamic bending, the shielding layer is prone to braiding wire loosening and aluminum foil cracking, resulting in a decrease in electromagnetic shielding performance. At the same time, the shielding layer has no reverse buffering stress dispersion function, which aggravates the damage to the internal insulation layer. The condition monitoring unit is not integrated with the main cable structure. The external sensing components have poor acid and high temperature resistance and cannot achieve the linkage sensing of corrosion-temperature-stress through the cable body structure. It can only monitor temperature or corrosion individually and cannot provide early warning of the risk of collaborative failure of the structural layer. Sudden failures can easily cause equipment downtime and increase maintenance costs.

[0003] In existing technologies, cable structure improvements often focus on enhancing the performance of a single material or structure, failing to develop a design approach that integrates layered, collaborative protection from the inside out, progressive stress relief, comprehensive media isolation, and integrated state perception. This results in difficulties in achieving breakthroughs in overall cable performance, making it impossible to meet the long-term reliable operation requirements of high-frequency movement in high-temperature and acidic environments. Therefore, developing a mobile cable with complementary and synergistic functions across its structural layers, possessing all-dimensional corrosion and high-temperature resistance, dynamic fatigue resistance, impermeability sealing, and intelligent linkage monitoring, has become the core key to solving the aforementioned technical challenges. Summary of the Invention

[0004] The technical problem to be solved by this invention is that the existing mobile cable structure layer in high-temperature acidic environments lacks synergistic protection, the seal is prone to failure, the resistance to dynamic fatigue is poor, the intelligent sensing is limited, and the processing technology is crude.

[0005] The technical solution adopted by this invention to solve its technical problem is: a high-reliability mobile cable for high-temperature acidic environments, comprising, from the inside out, a bipolar protective conductor, a thermally conductive insulation layer, an integrated shielding-buffering-sensing structure, a sealing-reinforcement core layer, and a gradient composite sheath layer; the integrated shielding-buffering-sensing structure includes a foamed TPE elastic buffer layer, a composite shielding layer, and a distributed optical fiber sensing unit; the sealing-reinforcement core layer includes a hydrophobic composite sealant and an aramid fiber braided reinforcement layer; the gradient composite sheath layer includes a modified PFA inner layer, a composite self-healing elastomer intermediate layer, and a plasma-modified fluororubber outer layer.

[0006] The surface of the bipolar protective conductor is also provided with a nano-diamond wear-resistant layer, and nano-yttrium oxide stabilizer is added to the titanium-based composite coating.

[0007] An aerogel insulation interlayer is added inside the thermally conductive and insulating synergistic layer, using nano-boron nitride + graphene composite modified PFA material.

[0008] The integrated shielding-buffering-sensing structure also includes a carbon nanotube conductive sensing layer, which is embedded and integrated with the distributed optical fiber sensing unit inside the foamed TPE elastic buffer layer.

[0009] The hydrophobic composite sealant is internally mixed with ceramic microspheres for pressure resistance and phase change energy storage microspheres, and the sealant contact angle is ≥130°.

[0010] The outermost layer of the gradient composite sheath is provided with a UV-cured scratch-resistant surface layer, and the middle layer of the composite self-healing elastomer is provided with microcapsule self-healing agent.

[0011] The composite shielding layer is internally mixed with carbonyl iron electromagnetic absorbing filler, with a weaving density ≥95%.

[0012] A processing technology for a high-reliability mobile cable for high-temperature acidic environments is characterized by comprising the following steps in sequence: conductor preparation and bipolar protection, thermally conductive insulation synergistic layer coating, shielding-buffering-sensing integrated structure preparation, sealing-reinforcement synergistic cable core preparation, gradient composite sheath co-extrusion, online laser holographic flaw detection, and finished product inspection and warehousing.

[0013] The conductor is prepared using a pre-twisting and shaping process, and after re-twisting, online tension calibration is performed, with tension fluctuation ≤ ±5N.

[0014] The online laser holographic flaw detection step uses laser holographic detection, with a defect recognition accuracy of ≤0.01mm, and can detect structural defects in coatings, insulation layers, shielding layers, and sealing layers in real time.

[0015] The beneficial effects of this invention are: (1) The present invention adopts a full-level synergistic protection structure consisting of a bipolar protective conductor, a thermally conductive insulation synergistic layer, a shielding-buffering-sensing integrated structure, a sealing-reinforcement synergistic cable core layer, and a gradient composite sheath layer. The materials of each layer are compatible and the thermal expansion coefficients are matched. There are no structural gaps. Combined with a multi-corrosion and high-temperature resistant material system consisting of a titanium-based composite coating, nano-yttrium oxide stabilizer, plasma-modified fluororubber outer layer, and superhydrophobic composite sealant, the acidic medium penetration channel is completely blocked, and the corrosion and high-temperature resistance is greatly improved. This increases the service life of the cable to more than 3.5 years under high temperature of 280℃ and 98% concentrated sulfuric acid medium, significantly extending the service life.

[0016] (2) The present invention constructs a four-level stress relief system by foamed TPE elastic buffer layer, composite self-healing elastomer intermediate layer, aramid fiber braided reinforcement layer and ceramic microsphere anti-compression particles. The stress generated by dynamic bending and mechanical impact can be absorbed and dispersed from the outside to the inside, avoiding the stress from acting directly on the inner insulation and conductor structure, so that the cable can withstand more than 1.2 million dynamic bending cycles without plastic damage to the structure and no performance degradation.

[0017] (3) The present invention integrates the distributed optical fiber sensing unit and the carbon nanotube conductive sensing layer into the foamed TPE elastic buffer layer. Relying on the dual-sensor collaborative monitoring mechanism, it realizes the real-time perception of all parameters of the cable internal temperature, medium corrosion, structural stress and surface cracks. It can provide early warning of fault risks such as medium penetration, structural aging and stress overload, with an early warning advance of ≥96h, which greatly reduces the probability of equipment downtime.

[0018] (4) The present invention adopts a refined processing technology of conductor pre-twisting and shaping, online tension calibration, double-layer co-extrusion, triple-layer co-extrusion linkage, and high-pressure full-domain sealing and filling, combined with online laser holographic flaw detection for full-process quality inspection, accurately controls the thickness, bonding force and form and position tolerance of each structural layer, identifies small structural defects in real time, and the product qualification rate is ≥99.5%, which is suitable for large-scale industrial production.

[0019] (5) The present invention integrates buffering, shielding and sensing functions into the same structural layer, sealing and reinforcement functions into the cable core layer, and corrosion resistance, self-repair and high temperature resistance functions into the sheath layer, avoiding the problem of excessive cable outer diameter and reduced flexibility caused by the superposition of multiple components. While improving the comprehensive protection and sensing performance, it ensures small cable outer diameter and high flexibility, perfectly adapting to high frequency dynamic movement conditions. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a schematic diagram of the radial cross-section structure of the cable of the present invention.

[0022] Figure 2 This is a flowchart of the processing technology of the present invention.

[0023] In the figure: 1. Bipolar protective conductor; 2. Thermally conductive and insulating synergistic layer; 3. Integrated shielding-buffering-sensing structure; 31. Foamed TPE elastic buffer layer; 32. Composite shielding layer; 33. Distributed optical fiber sensing unit; 34. Carbon nanotube conductive sensing layer; 4. Sealing-reinforcement synergistic cable core layer; 41. Hydrophobic composite sealant; 42. Aramid fiber braided reinforcement layer; 43. Ceramic microsphere compression-resistant particles; 44. Phase change energy storage microspheres; 5. Gradient composite sheath layer; 51. Modified PFA inner layer; 52. Composite self-healing elastomer intermediate layer; 53. Plasma-modified fluororubber outer layer; 54. UV-cured scratch-resistant surface layer. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] like Figure 1 , Figure 2 The cable shown is a high-reliability mobile cable for high-temperature acidic environments. From the inside out, it consists of a bipolar protective conductor 1, a thermally conductive insulation layer 2, an integrated shielding-buffering-sensing structure 3, a sealing-reinforcement core layer 4, and a gradient composite sheath layer 5.

[0027] The bipolar protective conductor 1 is made of 0.05-0.08mm ultra-fine copper wire drawn from electrolytic copper with a purity of ≥99.99%, and is formed by stranding 7 strands × 7 or 7 strands × 19 strands into a bundle, with a stranding pitch ratio of 12-15 times. The conductor surface is coated with a 5-10μm titanium-based composite coating by magnetron sputtering. The coating contains zirconium phosphate intercalating agent, tetra-needle zinc oxide whiskers and nano-yttrium oxide stabilizer. The bonding force is strengthened by vacuum annealing at 400℃. A 1-2μm nano-diamond wear-resistant layer is also deposited on the surface to improve the conductor's wear resistance and thermal creep resistance.

[0028] The thermally conductive and insulating synergistic layer 2 is wrapped around the outside of the bipolar protective conductor 1. It is made of PFA material modified by nano boron nitride and graphene, and has an aerogel thermal insulation interlayer inside. The thickness is controlled at 1.2-1.5mm. It has high insulation, high efficiency thermal conductivity and thermal insulation performance, and matches the thermal expansion coefficient of the conductor coating. It blocks the penetration of the medium and quickly disperses heat.

[0029] In the integrated shielding-buffering-sensing structure 3, the foamed TPE elastic buffer layer 31 tightly covers the thermally conductive and insulating synergistic layer 2 with a thickness of 0.8-1.0 mm; the distributed optical fiber sensing unit 33 and the carbon nanotube conductive sensing layer 34 are embedded and integrated inside the foamed TPE elastic buffer layer 31 to realize dual-sensor linkage monitoring; the composite shielding layer 32 covers the outside of the foamed TPE elastic buffer layer 31 and is made of 30° small-angle densely braided tin-plated copper wire and fluororesin-coated aluminum foil, and is mixed with carbonyl iron electromagnetic wave absorbing filler with a braiding density of ≥95%, which has both high electromagnetic shielding and wave absorption performance.

[0030] The sealing-reinforcement synergistic cable core layer 4 is made of multiple shielded-sensing cores twisted together at a pitch ratio of 10-12, and the gaps between the cores are fully filled with a hydrophobic composite sealant 41; the sealant is made of high-density polyethylene, ethylene-methyl methacrylate copolymer and nano-silica composite, and internally mixed with ceramic microbeads 43 and phase change energy storage microspheres 44, with a contact angle ≥130°. Among them, ceramic microspheres 43 are hollow alumina ceramic microspheres with a particle size of 5-15μm, a Mohs hardness ≥9, and a compressive strength ≥80MPa. Their function is to fill the pores of the sealant, improve the compressive strength and density of the sealing layer, and disperse bending stress. Phase change energy storage microspheres 44 have a paraffin / silica core-shell structure. The shell is nano-silica (thickness 100-200nm), and the core is high-melting-point paraffin with a melting point of 60-280℃ and a particle size of 8-20μm. Their function is to actively absorb and release heat within the cable's operating temperature range, regulate the internal temperature of the cable core, and delay the thermal aging of the structural layer. The sealant has an outer aramid fiber braided reinforcement layer 42 with a tensile strength ≥800MPa, which improves the tensile and bending resistance of the cable core.

[0031] The gradient composite sheath layer 5 is prepared using a three-layer co-extrusion process. The modified PFA inner layer 51 has a thickness of 0.5-0.8 mm and tightly wraps the aramid fiber braided reinforcement layer 42. The composite self-healing elastomer intermediate layer 52 has a thickness of 0.8-1.3 mm and contains microcapsule self-healing agents, giving it elastic buffering and self-healing properties. The plasma-modified fluororubber outer layer 53 has a thickness of 1.0-1.2 mm and serves as the core corrosion-resistant and high-temperature-resistant protective layer. The outermost layer is provided with a UV-cured scratch-resistant surface layer 54, which further enhances the sheath's wear and scratch resistance.

[0032] The specific processing steps of this invention are as follows: Conductor preparation and bipolar protection: Electrolytic copper was drawn into wire to 0.05-0.08mm, pre-twisted and shaped, and then bundled and re-twisted. The tension was calibrated online during the re-twisting process, and the tension fluctuation was ≤±5N. A titanium-based composite coating was deposited by magnetron sputtering and nano-yttrium oxide stabilizer was added. After annealing at 400℃, a nano-diamond wear-resistant layer was deposited to obtain the bipolar protected conductor 1. Thermally conductive and insulating synergistic layer coating: Nano-boron nitride, graphene-modified PFA and aerogel interlayer are co-extruded in two layers and coated on the outside of the bipolar protective conductor 1, with the thickness controlled at 1.2-1.5mm, cooled and shaped to obtain thermally conductive and insulating synergistic layer 2. Preparation of integrated shielding-buffering-sensing structure: Distributed optical fiber sensing unit 33, carbon nanotube conductive sensing layer 34 and foamed TPE elastomer are co-extruded to form foamed TPE elastic buffer layer 31, and then a composite shielding layer 32 is woven to ensure a weaving density ≥95% to obtain integrated shielding-buffering-sensing structure 3. Preparation of the sealing-reinforcement synergistic cable core: After multiple cores are stranded, hollow alumina ceramic microspheres and paraffin / silica core-shell phase change energy storage microspheres are mixed into a hydrophobic composite sealant at a mass ratio of 1:1. The sealant is injected into the gaps between the cores using a high-pressure full-area filling process to form a hydrophobic composite sealant 41, with a filling pressure of 0.8-1.2 MPa. An aramid fiber braided reinforcement layer 42 is woven on the outside and heat-set at 150℃ to obtain the sealing-reinforcement synergistic cable core layer 4. Gradient composite sheath layer co-extrusion: A three-layer co-extrusion production line is used to simultaneously extrude a modified PFA inner layer 51, a composite self-healing elastomer intermediate layer 52, and a plasma-modified fluororubber outer layer 53, and online UV curing is used to form a UV-cured scratch-resistant surface layer 54, thus obtaining the gradient composite sheath layer 5. Online laser holographic flaw detection: The entire cross-section of the cable is scanned using laser holographic inspection equipment, with a defect identification accuracy of ≤0.01mm, and unqualified products are automatically rejected; Finished product inspection and warehousing: The cables undergo comprehensive testing for corrosion resistance, high temperature resistance, bending resistance, shielding, sensing, and temperature control performance. After passing the tests, the cables are coiled, packaged, and stored in the warehouse.

[0033] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A high-reliability mobile cable for use in high-temperature acidic environments, characterized in that, From the inside out, the structure includes a bipolar protective conductor (1), a thermally conductive insulating synergistic layer (2), a shielding-buffering-sensing integrated structure (3), a sealing-reinforcing synergistic cable core layer (4), and a gradient composite sheath layer (5). The shielding-buffering-sensing integrated structure (3) includes a foamed TPE elastic buffer layer (31), a composite shielding layer (32), and a distributed optical fiber sensing unit (33). The sealing-reinforcing synergistic cable core layer (4) includes a hydrophobic composite sealant (41) and an aramid fiber braided reinforcing layer (42). The gradient composite sheath layer (5) includes a modified PFA inner layer (51), a composite self-healing elastomer intermediate layer (52), and a plasma-modified fluororubber outer layer (53).

2. The high-reliability mobile cable for high-temperature acidic environments according to claim 1, characterized in that, The surface of the bipolar protective conductor (1) is also provided with a nano-diamond wear-resistant layer, and a nano-yttrium oxide stabilizer is added to the titanium-based composite coating.

3. The high-reliability mobile cable for high-temperature acidic environments according to claim 1, characterized in that, The thermally conductive and insulating synergistic layer (2) is equipped with an aerogel thermal insulation interlayer, which is made of nano boron nitride + graphene composite modified PFA material.

4. The high-reliability mobile cable for high-temperature acidic environments according to claim 1, characterized in that, The shielding-buffering-sensing integrated structure (3) also includes a carbon nanotube conductive sensing layer (34), which is embedded and integrated with the distributed optical fiber sensing unit (33) inside the foamed TPE elastic buffer layer (31).

5. The high-reliability mobile cable for high-temperature acidic environments according to claim 1, characterized in that, The hydrophobic composite sealant (41) is internally mixed with ceramic microspheres (43) for pressure resistance and phase change energy storage microspheres (44), and the sealant contact angle is ≥130°.

6. The high-reliability mobile cable for high-temperature acidic environments according to claim 1, characterized in that, The outermost layer of the gradient composite sheath layer (5) is provided with an ultraviolet-cured scratch-resistant surface layer (54), and the composite self-healing elastomer intermediate layer (52) is provided with microcapsule self-healing agent.

7. The high-reliability mobile cable for high-temperature acidic environments according to claim 1, characterized in that, The composite shielding layer (32) is internally mixed with carbonyl iron electromagnetic absorbing filler with a weaving density ≥95%.

8. A processing method for a high-reliability mobile cable for high-temperature acidic environments as described in any one of claims 1-7, characterized in that, The steps are as follows: Conductor preparation and bipolar protection, thermally conductive and insulating synergistic layer coating, shielding-buffering-sensing integrated structure preparation, sealing-reinforcement synergistic cable core preparation, gradient composite sheath co-extrusion, online laser holographic flaw detection, and finished product inspection and warehousing.

9. The processing technology according to claim 8, characterized in that, The conductor is prepared using a pre-twisting and shaping process, and after re-twisting, online tension calibration is performed, with tension fluctuation ≤ ±5N.

10. The processing technology according to claim 8, characterized in that, The online laser holographic flaw detection step uses laser holographic detection, with a defect recognition accuracy of ≤0.01mm, and can detect structural defects in coatings, insulation layers, shielding layers, and sealing layers in real time.

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