A multifunctional composite layer cable material and its preparation method

Abstract

This invention proposes a method for preparing a multifunctional composite layer cable material. The method includes the following steps: surface activation pretreatment of conductive fibers; mixing the pretreated conductive fibers with an insulating polymer in a certain proportion and uniformly distributing the mixture on a substrate using spin coating technology to form a conductive layer; laying a composite material consisting of nanofillers and flame retardants on the surface of the conductive layer and compacting it using lamination technology to form a protective composite layer; mixing a functional reinforcing material with a high-performance resin and uniformly covering the protective composite layer by spraying to form a functional reinforcing layer that provides thermal and electrical conductivity and structural reinforcement; and applying a weather-resistant polymer material to the surface of the functional reinforcing layer and covering it through an impregnation process to form a durable outer protective layer, thus obtaining the cable material. This method achieves a comprehensive improvement in the cable material's signal transmission, mechanical strength, thermal and electrical conductivity, and environmental adaptability.

Description

Technical Field

[0001] This invention relates to the field of wires and cables, and in particular to a multifunctional composite layer structure cable material and its preparation method. Background Technology

[0002] In this era of rapid development in industrial automation and intelligent manufacturing, high-precision robotic equipment, flexible and reconfigurable production lines, and highly reliable sensing systems are becoming increasingly common. These next-generation industrial applications not only require stable signal and energy transmission but also place higher demands on transmission cables in terms of conductivity, mechanical strength, environmental resistance, flame retardancy, and thermal management capabilities. To ensure the continuous operation of production lines under conditions of extreme temperature differences, strong mechanical vibration, dust, oil, and corrosive chemicals, high-performance cable materials and manufacturing technologies suitable for smart factories and automated production equipment have become a key focus of research and development in related fields.

[0003] In existing technologies, traditional cables often employ single-layer or simple composite structures to meet basic transmission and protection requirements. For example, commonly used industrial cables typically consist of a conductor coated with a layer of ordinary polymer insulation, plus a basic protective layer, to achieve basic mechanical protection and simple environmental adaptability. However, this traditional approach has significant shortcomings: the lack of functional coatings and sophisticated multi-layer structural design leads to a sharp decline in cable reliability under high temperatures, continuous vibration, oil contamination, and chemical corrosion; insufficient bonding between the conductive layer and the substrate results in a significant decrease in conductivity and transmission stability after long-term use, potentially leading to insulation layer detachment, outer layer cracking, or internal structural deterioration. To address these technical deficiencies in traditional industrial cables under harsh operating environments and high-standard functional requirements, this invention proposes a method for preparing a multifunctional composite layer structure cable material to effectively improve the long-term stability and overall performance of cables in industrial automation and intelligent manufacturing applications. Summary of the Invention

[0004] To achieve the above objectives, the present invention provides a method for preparing a multifunctional composite layer structure cable material, comprising the following steps:

[0005] S1. Perform surface activation pretreatment on conductive fibers;

[0006] S2. The pretreated conductive fibers and insulating polymer are mixed in a certain proportion and evenly distributed on the substrate by spin coating technology to form a conductive layer. The conductive layer is then cured at 150-200°C using a hot pressing process.

[0007] S3. A composite material consisting of nanofillers and flame retardants is laid on the surface of the conductive layer and compacted using lamination technology to form a protective composite layer, with the lamination pressure controlled at 30–50 kg / cm². 2between;

[0008] S4. Mix the functional reinforcing material with the high-performance resin and evenly cover the protective composite layer by spraying to form a functional reinforcing layer. Use ultraviolet curing technology to complete the rapid curing of the functional reinforcing layer within 80 to 120 seconds.

[0009] S5. Apply a layer of weather-resistant polymer material to the surface of the functional enhancement layer, cover it with an impregnation process to form a durable outer protective layer, and perform heat treatment on the outer protective layer with the temperature controlled between 180 and 220°C to obtain the multifunctional composite layer structure cable material.

[0010] In some embodiments of the present invention, the conductive fiber is selected from one or more of carbon fiber, silver-coated fiber, stainless steel fiber, or copper-based fiber; the insulating polymer is selected from one or more of polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene, or polyimide; the nanofiller is selected from one or more of nano-alumina, nano-silicon, nano-titanium dioxide, nano-carbon nanotubes, or nano-graphene; the flame retardant is selected from one or more of brominated flame retardants, phosphorus-based flame retardants, aluminum hydroxide, magnesium hydroxide, or organophosphorus flame retardants; the reinforcing filler is selected from one or more of glass fiber, aramid fiber, carbon fiber, silicate fiber, nano-carbon nanotubes, graphene sheets, or polyester fiber; the high-performance resin is selected from one or more of epoxy resin, polyamide resin, polyurethane resin, unsaturated polyester resin, or phenolic resin; and the weather-resistant polymer material is selected from one or more of polyvinyl chloride, polyester elastomer, polyacrylonitrile, polybutadiene, or fluorocarbon polymer materials.

[0011] In some embodiments of the present invention, the conductive layer comprises, by weight percentage, 10-30 wt% of conductive fibers and 70-90 wt% of insulating polymer.

[0012] In some embodiments of the present invention, the substrate is formed by laminating one or more of metal foil, high-performance polymer film, glass fiber substrate and ceramic substrate through a lamination process.

[0013] In some embodiments of the present invention, the metal foil includes one or more of copper foil, stainless steel foil, or aluminum foil; the high-performance polymer film includes one or more of polyester film, polyimide film, or polytetrafluoroethylene film; the glass fiber substrate is glass fiber reinforced plastic; and the ceramic substrate includes one or more of alumina ceramic or silicon nitride ceramic.

[0014] In some embodiments of the present invention, the preprocessing in step S1 includes:

[0015] S1.1. Soak the conductive fiber in deionized water for 30-60 minutes at a temperature of 20-30°C. Use an ultrasonic cleaning device to clean the conductive fiber with an ultrasonic frequency of 30-50 kHz for 10 minutes.

[0016] S1.2 The conductive fiber is immersed in a nitric acid solution with a mass fraction of 20-30% or a sulfuric acid solution with a mass fraction of 10-20% by slow stirring for 15-30 minutes, and the temperature is controlled at 50-70℃.

[0017] S1.3. Take out the conductive fiber, rinse it repeatedly with deionized water until neutral, and immerse the neutralized conductive fiber in a solution containing 10% silane coupling agent for 50-60 minutes at a temperature of 30-50°C.

[0018] S1.4 Spray a layer of nano-silica coating onto the surface of the conductive fiber. Use a spraying device, spray temperature of 70-90℃, coating thickness controlled at 50nm, and use low-temperature plasma treatment, specifically oxygen or argon plasma, power of 100W, treatment time of 5min, to form a micro-rough structure on the surface of the nano-silica coating.

[0019] S1.5 Spread the treated conductive fibers evenly on a drying plate, place them in a drying oven, and dry them at 60-80°C for 2-4 hours. After drying, cool them to room temperature.

[0020] In some embodiments of the present invention, the method for preparing the multifunctional composite layer structure cable material according to claim 1 is characterized in that step S2 includes:

[0021] S2.1. The pretreated conductive fibers and the insulating polymer are mixed in proportion, and N,N-dimethylformamide or dimethyl sulfoxide solvent is added for dilution. The mass ratio of solvent to total solids is (60-70):(30-40). The mixture is stirred at 5000 r / min using a high-speed disperser for 20-40 min. The mixture is then treated with an ultrasonic dispersion device with a frequency of 30-50 kHz and a power of 200 W for 15 min to form a mixed slurry.

[0022] S2.2 Place the substrate in a cleaning tank and clean the surface with isopropanol. After cleaning, place the substrate in a plasma cleaner and treat it with oxygen plasma at a power of 100W for 5 minutes to enhance the hydrophilicity and adhesion of the substrate surface.

[0023] S2.3. Fix the pretreated substrate onto the vacuum suction cup of the rotary coater, ensuring its surface is flat and free of air bubbles. Use a dropper to evenly drop the mixed slurry onto the center of the substrate at a rate of 0.5 ml per square centimeter. Start the rotary coater. In the first stage, rotate at 500 r / min for 10 seconds to spread the slurry evenly. In the second stage, rotate at 2000 r / min for 30 seconds to form a uniform coating and remove excess slurry.

[0024] S2.4 In the spin coating process, electrostatic field-assisted technology is introduced. By setting a high-voltage electrode below the substrate and a grounded metal mesh above it, an electrostatic field is formed. By adjusting the intensity and direction of the electrostatic field, the microstructure of the coating is optimized.

[0025] S2.5. Transfer the coated substrate to a hot press, control the pressure to 5MPa, and preheat at 100℃ for 10 minutes using a program temperature control, then raise the temperature to 150-200℃ for curing, with a duration of 30 minutes.

[0026] In some embodiments of the present invention, in step S2.4, the electrostatic field-assisted technology specifically involves: finely adjusting the distance between the high-voltage electrode and the substrate within the range of 5 to 20 mm, and regulating the voltage between 3 and 7 kV to change the magnitude of the electrostatic field strength; simultaneously arranging multiple lateral electrodes capable of independently applying potentials around the substrate to make the electric field tilt or circulate in a specific direction; and setting a precisely positioned mechanical fine-tuning mechanism on the electrode mounting bracket to further refine the control of the electric field direction by adjusting the rotation angle.

[0027] In some embodiments of the present invention, in step S3, the lamination technique is at 30-50 kg / cm². 2 The pressure and temperature range of 150-180℃ are used to continuously press the nanofiller with double-sided heating rollers for 30 seconds, and ultrasonic vibration is introduced during the pressing process with a frequency of 30-50kHz to promote more uniform dispersion of the nanofiller.

[0028] In step S4, the spraying method involves spraying a mixed solution at a constant air pressure of 0.2 MPa through a high-precision atomizing nozzle at 40–60°C, and applying a weak electric field of 1 kV in the direction of the substrate plane to orient the droplets and optimize the distribution of the functional enhancement layer.

[0029] In step S5, the impregnation process involves slowly immersing the substrate into a solution containing weather-resistant polymer materials and micron-sized hollow spheres at an immersion speed of 1 mm / s, and promoting uniform distribution of the particles within the coating through ultrasonic oscillation at 30–40 kHz, thereby forming an external protective layer with a microporous structure and excellent weather resistance. The micron-sized hollow spheres include one or more of hollow alumina, hollow silica, hollow polystyrene, hollow polyacrylate, and hollow polyimide microspheres.

[0030] This invention proposes a multifunctional composite layer structure cable material, which is prepared by the method described above. The multifunctional composite layer structure cable material includes a substrate, a conductive layer, a protective composite layer, a functional enhancement layer, and an outer protective layer that are stacked sequentially.

[0031] Compared with existing technologies, the multifunctional composite layer structure cable material and its preparation method of this invention have the following advantages:

[0032] This preparation method significantly improves the overall performance of cable materials through the meticulous design of multi-layer composite structures and the application of advanced processes. Firstly, surface activation treatment enhances the bonding force between conductive fibers and insulating polymers, improving the conductivity and mechanical strength of the cable material. Secondly, the introduction of nanofillers and flame retardants not only improves the flame retardant properties of the cable material but also enhances its protective capabilities, ensuring safety and reliability in harsh environments. The thermal and electrical conductivity and structural strengthening effects of the functional reinforcing layer further optimize thermal management and mechanical properties, extending service life. Simultaneously, the application of weather-resistant polymer materials endows the cable material with excellent environmental adaptability, enabling it to maintain stable performance under complex conditions such as high temperature, low temperature, humidity, and corrosion. Overall, the multifunctional composite layer structure cable material prepared by this method possesses excellent electrical properties, mechanical strength, and environmental resistance, meeting the stringent requirements for efficient energy transmission, lightweight design, and high durability, and has broad application prospects and significant market competitiveness. Detailed Implementation

[0033] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0034] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0035] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0036] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0037] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0038] This invention proposes a method for preparing a multifunctional composite layer structure cable, comprising the following steps:

[0039] S1. Perform surface activation pretreatment on conductive fibers;

[0040] Step S1 involves surface activation pretreatment of the conductive fibers to enhance their bonding strength with the insulating polymer.

[0041] The conductive fiber is selected from one or more of carbon fiber, silver-coated fiber, stainless steel fiber or copper-based fiber.

[0042] In one embodiment of the present invention, step S1 includes:

[0043] S1.1 Soak the conductive fibers in deionized water for 30 to 60 minutes, for example, 30 minutes, 45 minutes, or 60 minutes, and control the temperature at 20 to 30 degrees Celsius, for example, 25 degrees Celsius or 30 degrees Celsius; use an ultrasonic cleaning device to clean the conductive fibers, with an ultrasonic frequency of 30 to 50 kHz, for example, 40 kHz, for a duration of 10 minutes.

[0044] Cleaning can remove dust, oil, and other impurities from the surface of conductive fibers, and ultrasonic cleaning can further improve the cleaning effect.

[0045] S1.2. Immerse the conductive fibers in a nitric acid or sulfuric acid solution of appropriate concentration by slow stirring for 15–30 minutes, for example, 15 minutes, 22 minutes, or 30 minutes; specifically, 20 minutes, at a temperature controlled at 50–70°C, for example, 60°C. The sulfuric acid solution used has a mass fraction of 10%–20%, and the nitric acid solution has a mass fraction of 20%–30%, for example, 10% sulfuric acid and 25% nitric acid.

[0046] This step is to increase the roughness of the fiber surface and introduce hydroxyl groups. Slow stirring is used to ensure that the solution contacts the conductive fiber evenly and avoids excessive local corrosion.

[0047] By fixing the specific concentrations of nitric acid and sulfuric acid, the repeatability of the acid etching step and the consistency of the treatment effect are ensured, improving the stability of the cable manufacturing process. Multiple acid options: Providing concentration ranges and fixed values ​​for both nitric acid and sulfuric acid enhances the applicability and flexibility of the method, adapting to the surface activation requirements of different conductive fiber materials. Optimized surface activation effect: The reasonable selection of acid concentration ranges and fixed values ​​helps to improve the surface activity and bonding performance of conductive fibers while avoiding adverse effects on the fiber structure, ensuring the performance and reliability of the final cable.

[0048] S1.3. Take out the conductive fiber and rinse it repeatedly with deionized water until neutral. Soak the neutralized conductive fiber in a solution containing 10% silane coupling agent (such as APTES, 3-aminopropyltriethoxysilane) for 50-60 minutes at a temperature of 30-50°C, for example, 60 minutes at 40°C.

[0049] Soaking in a silane coupling agent solution can introduce amino functional groups, thereby enhancing the adhesion between the fiber and the polymer matrix.

[0050] S1.4. Spray a layer of nano-silica coating onto the surface of the conductive fiber. Use a spraying device with a spraying temperature of 70-90℃ and a coating thickness of 50nm. Use low-temperature plasma treatment, specifically oxygen or argon plasma with a power of 100W and a treatment time of 5min, to form a micro-rough structure on the surface of the nano-silica coating.

[0051] The micro-roughened structure formed by the nano-silica coating and low-temperature plasma treatment provides the conductive fibers with a larger surface area and more surface protrusions and depressions. This micro-irregular surface enables greater mechanical interlocking when in contact with the polymer matrix, making it easier for polymer molecular chains to wet and fill these tiny gaps, thus forming a stable solid-solid interface coupling on the fiber surface. Furthermore, the micro-roughened structure increases the number of effective contact points on the fiber surface, providing more binding sites for various chemical bonds and weak van der Waals forces. This overall enhances the adhesion and interfacial strength between the conductive fibers and the polymer, allowing the final composite material to maintain excellent structural stability and conductivity under mechanical loads and environmental stresses.

[0052] S1.5 Spread the treated conductive fibers evenly on the drying plate, place them in a drying oven, and dry them at 60-80℃ for 2-4 hours. For example, the temperature can be 60℃, 70℃, or 80℃, and the drying time can be 2 hours, 3 hours, or 4 hours. After drying, cool to room temperature.

[0053] The drying step is to remove surface moisture and solvents, ensuring the fibers are dry and ready for the next step of composite material preparation.

[0054] Through detailed surface activation pretreatment steps, this method effectively enhances the bonding force between conductive fibers and insulating polymers, significantly improving the conductivity and mechanical strength of the cable. Ultrasonic-assisted cleaning and the introduction of a nano-silica coating ensure thorough cleaning and high activity of the fiber surface, optimizing the interfacial bonding between the fiber and the polymer matrix. Low-temperature plasma treatment further improves the microstructure of the fiber surface, enhancing adhesion performance and the overall stability of the composite material. Ultimately, the pretreated conductive fibers possess superior surface properties, resulting in multifunctional composite layer cables exhibiting superior performance in conductivity, mechanical strength, and environmental adaptability.

[0055] S2. The pretreated conductive fibers and insulating polymer are mixed in proportion and evenly distributed on the substrate by spin coating technology to form a conductive layer. The conductive layer is cured at 150-200°C using a hot pressing process, for example, 150°C, 175°C, or 200°C. The insulating polymer is selected from one or more of polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene, or polyimide.

[0056] The conductive fiber accounts for 10-30 wt% and the insulating polymer accounts for 70-90 wt% by weight percentage. For example, the ratio of conductive fiber to insulating polymer can be 10:90, 20:80, or 30:70.

[0057] The substrate is made by laminating one or more of the following materials: metal foil, high-performance polymer film, glass fiber substrate, and ceramic substrate.

[0058] Metal foils offer excellent conductivity and mechanical strength, making them suitable for cables requiring high conductivity and structural stability; high-performance polymer films provide good insulation and flexibility, making them suitable for cables requiring lightweight and high insulation performance; glass fiber substrates offer good mechanical strength and heat resistance, making them suitable for cables used in high-strength and high-temperature environments; ceramic substrates offer excellent heat resistance and corrosion resistance, making them suitable for cables in extreme environmental conditions; composite material substrates combine the advantages of multiple materials, allowing for customized cable performance to meet specific needs.

[0059] The metal foil includes one or more of copper foil, stainless steel foil, or aluminum foil; the high-performance polymer film includes one or more of polyester film, polyimide film, or polytetrafluoroethylene film; the glass fiber substrate is glass fiber reinforced plastic; and the ceramic substrate includes one or more of alumina ceramic or silicon nitride ceramic.

[0060] Step S2 includes:

[0061] S2.1. The pretreated conductive fibers are mixed with the insulating polymer in a certain proportion, and N,N-dimethylformamide or dimethyl sulfoxide solvent is added for dilution. The mass ratio of solvent to total solids is (60-70):(30-40), for example, 60:40 or 70:30. The mixture is stirred at 5000 r / min using a high-speed disperser for 20-40 min, for example, 20 min, 30 min or 40 min. The mixture is then treated with an ultrasonic dispersion device with a frequency of 30-50 kHz and a power of 200 W for 15 min to form a mixed slurry.

[0062] S2.2 Place the substrate in a cleaning tank and clean the surface with isopropanol. After cleaning, place the substrate in a plasma cleaner and treat it with oxygen plasma at a power of 100W for 5 minutes to enhance the hydrophilicity and adhesion of the substrate surface.

[0063] S2.3. Fix the pretreated substrate onto the vacuum chuck of the rotary coater, ensuring its surface is flat and free of air bubbles. Use a dropper to evenly drop the mixed slurry onto the center of the substrate at a rate of 0.5 ml per square centimeter. Start the rotary coater. In the first stage, rotate at 500 r / min for 10 seconds to spread the slurry evenly. In the second stage, rotate at 2000 r / min for 30 seconds to form a uniform coating and remove any excess slurry.

[0064] S2.4. During the spin coating process, electrostatic field-assisted technology is introduced. A high-voltage electrode is set below the substrate, and a grounded metal mesh is set above the substrate to form an electrostatic field.

[0065] The electrostatic field can guide charged conductive fibers and insulating polymer particles to be distributed more evenly in the coating, and control the deposition direction and arrangement of the particles, thereby achieving precise control over the micro-particle size and distribution.

[0066] By adjusting the intensity and direction of the electrostatic field, the microstructure of the coating is optimized, thereby improving the interfacial bonding between the conductive fibers and insulating polymers and the substrate.

[0067] In step S2.4, the electrostatic field-assisted technology specifically involves: finely adjusting the distance between the high-voltage electrode and the substrate within the range of 5–20 mm, and regulating the voltage between 3–7 kV to change the magnitude of the electrostatic field strength, thereby controlling the microscopic distribution density of conductive fibers and insulating polymer particles; simultaneously, arranging multiple lateral electrodes capable of independently applying potentials around the substrate to tilt or distribute the electric field in a specific direction, thereby achieving flexible changes and gradient adjustments in the electric field direction; furthermore, a precisely positioned mechanical fine-tuning mechanism can be installed on the electrode mounting bracket to further refine the control of the electric field direction by adjusting the rotation angle.

[0068] The electrostatic field strength is directly proportional to the voltage applied between the electrodes. When it is necessary to increase the electrostatic field strength to make the particles more compactly distributed or reduce particle aggregation, the voltage can be gradually increased from the original setting of 5kV to 6kV, 7kV or even higher; if it is necessary to weaken the electrostatic field strength to prevent excessive directional arrangement, the voltage can be reduced to 4kV or 3kV. By increasing or decreasing the voltage, the electric field strength can be flexibly adjusted within a range.

[0069] Shortening the distance between electrodes increases the electric field strength, while increasing the electrode spacing decreases it. Movable electrodes or a precision mechanical fine-tuning platform can be designed into the experimental setup to achieve precise control of the electric field strength by changing the distance between the electrodes and the substrate (e.g., from 10 mm to 5 mm or 20 mm).

[0070] When a high-voltage electrode is located below the substrate and a grounded metal mesh is located above it, the electric field direction is primarily vertical. If lateral electrodes are added (e.g., a set of energized auxiliary electrodes is placed on each side of the substrate), a horizontal component can be introduced into the vertical field by adjusting the voltage of the lateral electrodes, thereby fine-tuning the electric field direction in two-dimensional space. By controlling the potential of each lateral electrode individually, the electric field can be tilted or horizontally offset, thus guiding the particles to distribute and orient themselves in a specific direction.

[0071] Multiple independently adjustable electrode arrays (e.g., one electrode in each of the four directions) are arranged around the substrate. High or low voltages are selectively applied to some of these electrodes as needed to create a composite electric field. By precisely controlling the potential distribution of each electrode, more flexible electric field direction control can be achieved in the plane. For example, the electric field can be tilted to a specific side, or the electrode excitation sequence can be gradually changed during the coating process, resulting in a controllable gradient or ordered distribution of particles over time.

[0072] Besides electrical control, mechanical structural modifications can also be employed. For example, the substrate fixing device can be mounted on a rotatable bracket. By adjusting the bracket's rotation angle, the orientation of the substrate surface relative to the electrodes can be changed, thereby altering the relative relationship between the direction of the electric field and the substrate plane. Combined with voltage regulation and a multi-electrode array design, dynamic changes in the electric field direction can be achieved during the coating process.

[0073] To ensure precise and effective adjustment of the electric field strength and direction, an electric field sensor can be integrated into the device, or an optical microscope can be used to observe the distribution of coating particles in real time. When the electric field sensor or online image analysis detects that the particle distribution is uneven or does not meet expectations, the voltage, electrode spacing, or excitation voltage of the lateral electrodes can be finely adjusted immediately to achieve closed-loop feedback control and ensure that the particles are oriented in an ideal manner. For example, when particles are significantly dense in a certain area, resulting in uneven distribution, the main electrode voltage can be moderately increased (e.g., from 5kV to 5.5kV) to enhance the driving force for particles to migrate outward from the aggregation point under the influence of the electric field. At the same time, the excitation voltage of the side electrodes can be slightly increased (by about 5-10%) to guide particles to diffuse over a wider range by increasing the lateral electric field component. When particles are dense at the edge of the substrate and sparse in the central area, the side electrode voltage can be reduced (by about 10%) to weaken the lateral pull of the electric field at the edge, preventing particles from excessively aggregating towards the edge. At the same time, the electrode spacing can be slightly increased (e.g., from 10mm to 12mm) to slightly weaken the overall electric field strength, helping particles to stay in the central area and fill the sparse area. When particles have no obvious orientation and are randomly distributed, the excitation voltage of the side electrodes can be finely adjusted (by about 5%) to change the electric field direction distribution, giving the particles a more definite directionality under the force. If the orientation effect is still not ideal, the main electrode voltage can be gradually increased or decreased (in increments of 0.5 kV each time) after feedback monitoring to find the optimal electric field strength for better orientation. When there are void areas on the substrate surface with insufficient particles, the electrode spacing can be appropriately reduced (e.g., from 12 mm to 9 mm) to increase the local electric field strength and guide distant particles to migrate towards the void areas. At the same time, the lateral electrode voltage can be finely adjusted (fluctuating up or down by 5%) to slightly deflect the electric field direction, "pushing" the particles into the blank areas and gradually filling the sparse areas. When the particles are agglomerated, resulting in uneven particle size distribution, the main electrode voltage can be reduced (e.g., from 6 kV to 4.5 kV) to weaken the particle acceleration and reduce agglomeration. At the same time, the lateral electrode voltage can be slightly increased (by about 5%) to disperse the particles in the horizontal direction, and the local electric field gradient can be increased by slightly adjusting the electrode spacing (e.g., shortening it by 2 mm) to assist in particle deagglomeration and redistribution.

[0074] S2.5 Transfer the coated substrate to a hot press, control the pressure to 5MPa, and preheat at 100℃ for 10 minutes using a program temperature control, then raise the temperature to 150-200℃ for curing, for example, 150℃, 165℃, or 200℃, for a duration of 30 minutes.

[0075] This ensures that the solvent inside the coating evaporates completely and achieves a tight bond between the conductive fibers and the insulating polymer.

[0076] Utilizing a spin coating process and an innovative electrostatic field-assisted technique, the conductive layer prepared by this method exhibits excellent uniformity and microstructure. High-speed dispersion and ultrasonic treatment ensure thorough mixing and dispersion of the conductive fibers and insulating polymer, while the electrostatic field-assisted technique further optimizes the particle distribution and arrangement, significantly improving the interfacial bonding between the conductive fibers and the insulating polymer. The final conductive layer possesses superior conductivity and mechanical strength, laying a solid foundation for improving the overall performance of multifunctional composite layered cables.

[0077] S3. A composite material consisting of nanofillers and flame retardants is laid on the surface of the conductive layer and compacted using lamination technology to form a protective composite layer, with the lamination pressure controlled at 30–50 kg / cm². 2 For example, it could be 30kg / cm 2 40kg / cm 2 50kg / cm 2 The nanofiller is selected from one or more of nano-alumina, nano-silicon, nano-titanium dioxide, nano-carbon nanotubes, or nano-graphene; the flame retardant is selected from one or more of brominated flame retardants, phosphorus-based flame retardants, aluminum hydroxide, magnesium hydroxide, or organophosphorus flame retardants.

[0078] In step S3, the lamination technology involves continuous pressing for 30 seconds using double-sided heated rollers within the temperature range of 150 to 180°C, for example, 150°C, 170°C, or 180°C. Ultrasonic vibration is introduced during the pressing process with a frequency of 30 to 50 kHz to promote more uniform dispersion of the nanofiller.

[0079] Lamination ensures precise alignment of composite material layers, guaranteeing adhesion between layers. Vibration is introduced during lamination to reduce bubble formation, thereby improving the uniformity and surface quality of the composite layer.

[0080] S4. The functional reinforcing material is mixed with the high-performance resin and uniformly coated onto the protective composite layer by spraying to form a functional reinforcing layer that is thermally and electrically conductive and structurally strengthened. The functional reinforcing layer is rapidly cured within 80 to 120 seconds using ultraviolet curing technology, for example, 80 seconds, 95 seconds, or 120 seconds. The reinforcing filler is selected from one or more of glass fiber, aramid fiber, carbon fiber, silicate fiber, carbon nanotubes, graphene sheets, or polyester fiber, and the high-performance resin is selected from one or more of epoxy resin, polyamide resin, polyurethane resin, unsaturated polyester resin, or phenolic resin.

[0081] In step S4, the spraying method involves spraying a mixed solution at a constant air pressure of 0.2 MPa through a high-precision atomizing nozzle at a temperature of 40–60°C. For example, the temperature could be 40°C or 50°C. A weak electric field of 1 kV is applied in the direction of the substrate plane to orient the droplets, thereby optimizing the micro-particle size distribution of the functional enhancement layer.

[0082] This process ensures uniform coating coverage and, combined with repeated spraying, achieves more uniform and precise control of the functional coating thickness. The spraying thickness is adjusted based on the measurement results after each coating to ensure that the final coating is uniform and defect-free.

[0083] S5. Apply a layer of weather-resistant polymer material to the surface of the functional reinforcement layer and cover it through an impregnation process to form a durable outer protective layer; perform heat treatment with the temperature controlled between 180 and 220°C, wherein the weather-resistant polymer material is selected from one or more of polyvinyl chloride, polyester elastomer, polyacrylonitrile, polybutadiene, or fluorocarbon polymer materials.

[0084] In step S5, the impregnation process involves slowly immersing the substrate into a solution containing weather-resistant polymer materials and micron-sized hollow spheres at an immersion speed of 1 mm / s, and promoting uniform distribution of the particles within the coating through ultrasonic oscillation at 30–50 kHz, thereby forming an external protective layer with a microporous structure and excellent weather resistance; wherein, the micron-sized hollow spheres include one or more of hollow alumina, hollow silica, hollow polystyrene, hollow polyacrylate, and hollow polyimide microspheres.

[0085] The coating is carried out using vacuum impregnation technology, in which the substrate is immersed in a liquid solution containing resin and the immersion time is maintained under vacuum for 30 minutes, with the temperature controlled at 25-30°C. By removing air bubbles in the solution, it is ensured that each inner layer is fully wetted and coated, thus avoiding the formation of air bubbles and optimizing the chemical bonding of the material.

[0086] This preparation method utilizes a multi-layer composite structure design to progressively construct a cable material with superior performance. First, step S1 involves surface activation pretreatment of the conductive fibers to enhance their adhesion to the insulating polymer. Next, step S2 mixes the pretreated conductive fibers and insulating polymer in a specific ratio, and distributes them uniformly on a substrate using spin coating technology to form a highly efficient conductive layer. This layer is then cured using a hot-pressing process to ensure its stability and consistency. Step S3 lays a composite material consisting of nanofillers and flame retardants on the surface of the conductive layer, and compacts it using lamination technology to form a protective composite layer that provides mechanical protection and flame retardant properties. Subsequently, step S4 mixes functional reinforcing materials with a high-performance resin, and uniformly coats the protective composite layer using a spraying method to form a reinforcing layer with thermal and electrical conductivity and structural strengthening functions. This layer is then rapidly cured using ultraviolet curing technology to improve interlayer adhesion and overall structural strength. Finally, in step S5, a weather-resistant polymer material is applied to the surface of the functional enhancement layer and covered by an impregnation process to form a durable outer protective layer. Heat treatment is then performed to ensure that each layer is firmly bonded, ultimately obtaining a multifunctional composite layer structure cable material with high conductivity, excellent mechanical strength, and outstanding environmental adaptability.

[0087] This invention also proposes a multifunctional composite layer cable material, comprising a substrate, a conductive layer, a protective composite layer, a functional reinforcement layer, and an outer protective layer stacked sequentially. The conductive fibers are pretreated with surface activation, mixed with an insulating polymer, and then spin-coated and hot-pressed to form a uniform and dense conductive layer. A composite material consisting of nanofillers and flame retardants is then laid on top and compacted using a lamination process to form a protective layer with mechanical reinforcement and safe flame retardant properties. A high-performance resin is then mixed with the functional reinforcement material, and a thermally conductive, electrically conductive, and structurally reinforcing functional reinforcement layer is rapidly constructed through spraying and UV curing. Finally, a weather-resistant polymer material is impregnated or coated onto the surface of the reinforcing layer, followed by heat treatment, to obtain an outer protective layer with excellent environmental adaptability and long-term stability. This process produces a multifunctional composite layer cable material with multi-layered functions and reliable durability.

[0088] The cable formed by combining the cable material and conductor core of this invention involves first selecting a high-purity, low-resistivity metal wire (such as copper or silver-plated copper wire) as the conductor core, and cleaning and drying its surface to ensure good adhesion of subsequent layers. Next, the conductive layer material, which has undergone surface activation pretreatment and is mixed with an insulating polymer, and then spin-coated and cured, is uniformly wound onto the surface of the conductive core in the form of a strip or a flexible semi-cured film. During the winding process, appropriate tension and stacking density must be maintained to ensure close contact between the conductive fibers and the insulating substrate, avoiding air gaps and uneven areas. Then, a protective composite layer containing nanofillers and flame retardants, previously cured by lamination technology, is wrapped around the outside of the conductive layer (this layer can be made into a strip or tubular preform). This protective layer is then tightly bonded to the conductive layer using hot pressing or lamination equipment, forming a stable and highly protective intermediate substrate outside the conductive layer. Finally, the wound and protected core is... The spraying process involves uniformly spraying a high-performance resin slurry containing functional reinforcing materials onto the surface, followed by rapid curing and shaping using ultraviolet light to form a composite coating with excellent thermal conductivity, electrical conductivity, and structural reinforcement. A solution or coating containing micron-sized hollow spheres and weather-resistant polymer materials is then uniformly impregnated onto the surface of the functional reinforcement layer under vacuum pressure to eliminate air bubbles and ensure the hollow spheres are evenly distributed within the outer coating. Subsequently, a heat treatment process cures the outer layer and firmly adheres it to the previous layer, thus endowing the cable with excellent weather resistance, UV resistance, and chemical corrosion resistance. Finally, the multi-layered cable is placed in a constant-temperature oven or heat treatment furnace for curing. This process helps further improve the interlayer bonding strength and optimizes the overall mechanical, electrical, and environmental adaptability characteristics of the cable. After curing, the cable undergoes necessary inspection and cutting to ensure it meets the design specifications and performance indicators, making it ready for use.

[0089] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing a multifunctional composite layered cable material, characterized in that, Including the following steps: S1. Perform surface activation pretreatment on conductive fibers; S2. The pretreated conductive fibers and insulating polymer are mixed in a certain proportion and evenly distributed on the substrate by spin coating technology to form a conductive layer. The conductive layer is then cured at 150~200°C using a hot pressing process. S3. A composite material consisting of nanofillers and flame retardants is laid on the surface of the conductive layer and compacted using lamination technology to form a protective composite layer, with the lamination pressure controlled at 30~50 kg / cm². 2 between; S4. Mix the functional reinforcing material with the high-performance resin and evenly cover the protective composite layer by spraying to form a functional reinforcing layer. Use ultraviolet curing technology to complete the rapid curing of the functional reinforcing layer within 80~120 seconds. S5. Apply a layer of weather-resistant polymer material to the surface of the functional enhancement layer, cover it with an impregnation process to form a durable outer protective layer, and perform heat treatment on the outer protective layer with the temperature controlled between 180 and 220°C to obtain the multifunctional composite layer structure cable material.

2. The method for preparing the multifunctional composite layer structure cable material according to claim 1, characterized in that, The conductive fiber is selected from one or more of carbon fiber, silver-coated fiber, stainless steel fiber, or copper-based fiber; the insulating polymer is selected from one or more of polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene, or polyimide; the nanofiller is selected from one or more of nano-alumina, nano-silicon, nano-titanium dioxide, nano-carbon nanotubes, or nano-graphene; the flame retardant is selected from one or more of brominated flame retardants, phosphorus-based flame retardants, aluminum hydroxide, magnesium hydroxide, or organophosphorus flame retardants; the functional reinforcing material is selected from one or more of glass fiber, aramid fiber, carbon fiber, silicate fiber, nano-carbon nanotubes, graphene sheets, or polyester fiber; the high-performance resin is selected from one or more of epoxy resin, polyamide resin, polyurethane resin, unsaturated polyester resin, or phenolic resin; and the weather-resistant polymer material is selected from one or more of polyvinyl chloride, polyester elastomer, polyacrylonitrile, polybutadiene, or fluorocarbon polymer materials.

3. The method for preparing the multifunctional composite layer structure cable material according to claim 1, characterized in that, In the conductive layer, the conductive fibers account for 10-30 wt% and the insulating polymer accounts for 70-90 wt% by weight percentage.

4. The method for preparing the multifunctional composite layer structure cable material according to claim 1, characterized in that, The substrate is formed by laminating one or more of the following materials: metal foil, high-performance polymer film, glass fiber substrate, and ceramic substrate.

5. The method for preparing the multifunctional composite layer structure cable material according to claim 4, characterized in that, The metal foil includes one or more of copper foil, stainless steel foil, or aluminum foil; the high-performance polymer film includes one or more of polyester film, polyimide film, or polytetrafluoroethylene film; the glass fiber substrate is glass fiber reinforced plastic; and the ceramic substrate includes one or more of alumina ceramic or silicon nitride ceramic.

6. The method for preparing a multifunctional composite layer structure cable material according to claim 1, characterized in that, The preprocessing in step S1 includes: S1.1 Soak the conductive fiber in deionized water for 30-60 minutes at a temperature of 20-30°C; use an ultrasonic cleaning device to clean the conductive fiber with an ultrasonic frequency of 30-50 kHz for 10 minutes. S1.

2. The conductive fiber is immersed in a nitric acid solution with a mass fraction of 20-30% or a sulfuric acid solution with a mass fraction of 10-20% by slow stirring for 15-30 minutes, and the temperature is controlled at 50-70℃. S1.

3. Take out the conductive fiber, rinse it repeatedly with deionized water until neutral, and immerse the neutralized conductive fiber in a solution containing 10% silane coupling agent for 50-60 minutes at a temperature of 30-50°C. S1.4 Spray a layer of nano-silica coating onto the surface of the conductive fiber. Use a spraying device, spray temperature is 70~90℃, coating thickness is controlled at 50nm, and low-temperature plasma treatment is used, specifically oxygen or argon plasma, power is 100W, treatment time is 5min, to form a micro-rough structure on the surface of the nano-silica coating. S1.5 Spread the treated conductive fibers evenly on a drying plate, place them in a drying oven, and dry them at 60~80℃ for 2~4 hours. After drying, cool them to room temperature.

7. The method for preparing the multifunctional composite layer structure cable material according to claim 1, characterized in that, Step S2 includes: S2.

1. The pretreated conductive fibers and the insulating polymer are mixed in proportion, and N,N-dimethylformamide or dimethyl sulfoxide solvent is added for dilution. The mass ratio of solvent to total solids is (60~70):(30~40). The mixture is stirred at 5000 r / min for 20~40 min using a high-speed disperser. The mixture is then treated with an ultrasonic dispersion device at a frequency of 30~50 kHz and a power of 200 W for 15 min to form a mixed slurry. S2.2 Place the substrate in a cleaning tank and clean the surface with isopropanol. After cleaning, place the substrate in a plasma cleaner and treat it with oxygen plasma at a power of 100W for 5 minutes to enhance the hydrophilicity and adhesion of the substrate surface. S2.

3. Fix the pretreated substrate onto the vacuum suction cup of the rotary coater, ensuring its surface is flat and free of air bubbles. Use a dropper to evenly drop the mixed slurry onto the center of the substrate at a rate of 0.5 ml per square centimeter. Start the rotary coater. In the first stage, rotate at 500 r / min for 10 seconds to spread the slurry evenly. In the second stage, rotate at 2000 r / min for 30 seconds to form a uniform coating and remove excess slurry. S2.4 In the spin coating process, electrostatic field-assisted technology is introduced. By setting a high-voltage electrode below the substrate and a grounded metal mesh above it, an electrostatic field is formed. By adjusting the intensity and direction of the electrostatic field, the microstructure of the coating is optimized. S2.5 Transfer the coated substrate to a hot press, control the pressure to 5 MPa, and preheat at 100°C for 10 minutes using a programmed temperature control, then raise the temperature to 150~200°C for curing, with a duration of 30 minutes.

8. The method for preparing the multifunctional composite layer structure cable material according to claim 7, characterized in that, In step S2.4, the electrostatic field-assisted technology specifically involves: finely adjusting the distance between the high-voltage electrode and the substrate within the range of 5 to 20 mm, and regulating the voltage between 3 and 7 kV to change the magnitude of the electrostatic field strength; simultaneously arranging multiple lateral electrodes capable of independently applying potentials around the substrate to make the electric field tilt or circulate in a specific direction; and setting a precisely positioned mechanical fine-tuning mechanism on the electrode mounting bracket to further refine the control of the electric field direction by adjusting the rotation angle.

9. The method for preparing the multifunctional composite layer structure cable material according to claim 1, characterized in that: In step S3, the lamination technology involves continuous pressing for 30 seconds using double-sided heated rollers at a pressure of 30-50 kg / cm² and a temperature range of 150-180°C, and introducing ultrasonic vibration at a frequency of 30-50 kHz during the pressing process to promote more uniform dispersion of the nanofiller. In step S4, the spraying method involves spraying a mixed solution at a constant air pressure of 0.2 MPa through a high-precision atomizing nozzle at 40~60℃, and applying a weak electric field of 1 kV in the direction of the substrate plane to orient the droplets and optimize the distribution of the functional enhancement layer. In step S5, the impregnation process involves slowly immersing the substrate into a solution containing weather-resistant polymer materials and micron-sized hollow spheres at an immersion speed of 1 mm / s, and promoting uniform distribution of the particles within the coating by ultrasonic oscillation at 30-40 kHz, thereby forming an external protective layer with a microporous structure and excellent weather resistance. The micron-sized hollow spheres include one or more of hollow alumina, hollow silica, hollow polystyrene, hollow polyacrylate, and hollow polyimide microspheres.

10. A multifunctional composite layer structure cable material, characterized in that, The multifunctional composite layer structure cable material is prepared by the preparation method of any one of claims 1-9, wherein the multifunctional composite layer structure cable material comprises a substrate, a conductive layer, a protective composite layer, a functional enhancement layer and an outer protective layer stacked sequentially.