An electric leakage resistant double-layer protective cloth electric wire

Abstract

The application discloses an anti-creeping double-layer protective cloth wire, which comprises a conductor, an inner insulation layer and an outer protective layer; the molecular chains of the inner insulation layer are oriented along the axial direction of the conductor, and the molecular chains of the outer protective layer are oriented along the circumferential direction of the conductor; meanwhile, the relative dielectric constant of the inner insulation layer is higher than that of the outer protective layer, so that the radial dielectric constant distribution is formed as high inside and low outside. A corresponding manufacturing method realizes the above microstructure through specific co-extrusion and orientation processes. Through the synergistic design of the orthogonal orientation of the molecular chains and the dielectric constant gradient, the application physically optimizes the electric field distribution, suppresses the charge accumulation, and takes into account the mechanical strength and heat dissipation, so that the anti-creeping reliability and comprehensive durability of the cloth wire during long-term operation are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of wire and cable technology, specifically to a double-layer protective cloth wire with leakage protection. Background Technology

[0002] Electrical wiring is widely used for power transmission within buildings, and its long-term operational reliability is directly related to electrical safety. Leakage is one of the main failure modes of electrical wiring, often caused by localized deterioration of the insulation layer under the long-term influence of electric and thermal fields.

[0003] Currently, using double-insulation structures is a common method to improve the overall performance of electrical wires. However, there is a fundamental contradiction in the existing double-insulated wires in terms of improving long-term leakage resistance: the inner insulation and outer sheath are usually made of materials with different properties to meet different needs (such as high insulation for the inner layer and high toughness for the outer layer), but these two materials are often mismatched in terms of key dielectric constants and polymer chain microstructures and have not been designed in a coordinated manner.

[0004] Specifically, this manifests as follows: Dielectric mismatch leads to electric field distortion: If the dielectric constants of the inner and outer layers are mismatched, an electric field abrupt change will occur at the interface, which will aggravate the accumulation of space charge, become the starting point of partial discharge and an accelerator of insulation aging.

[0005] Random microstructure leads to performance limitations: Traditional extrusion processes result in random orientation of the polymer chains in the insulating layer. This disordered structure causes inherent and uncontrollable anisotropy in the material's dielectric strength, thermal conductivity, and mechanical properties. Under complex stress, weak points in the disordered structure are prone to failure first.

[0006] To address these issues, existing technologies often focus on material formulation or increasing thickness. However, these methods are often only temporary solutions and may introduce new problems such as increased costs and decreased flexibility. How to optimize the electric field distribution and delay aging at the source by starting from the fundamental level of the microstructure design of the insulating layer, actively controlling the molecular chain arrangement and coordinating it with the macroscopic dielectric property distribution, has become a pressing but long-neglected technical challenge in this field. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide a double-layer protective electrical wire with leakage protection to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, a specific embodiment of the present invention provides a double-layer protective electrical wire with leakage protection, comprising a conductor, an inner insulation layer, and an outer protective layer; the inner insulation layer tightly covers the outer surface of the conductor; the outer protective layer tightly covers the outer surface of the inner insulation layer; wherein, the molecular chains of the inner insulation layer are oriented along the axial direction of the conductor, and the molecular chains of the outer protective layer are oriented along the circumferential direction of the conductor; the relative permittivity of the inner insulation layer is higher than that of the outer protective layer, resulting in a dielectric constant distribution that is higher inside and lower outside in the radial direction.

[0009] In addition, the double-layer protective wire for leakage protection proposed in this application may also have the following additional technical features: In one embodiment of this application, a transition adhesive layer is further provided between the inner insulating layer and the outer protective layer. The thickness of the transition adhesive layer is 0.02 mm to 0.10 mm, and the T-type peel strength measured with reference to GB / T 2791-1995 is ≥2.5 N / mm.

[0010] In one embodiment of this application, the inner insulation layer is composed of a cross-linked polyethylene matrix and nano-thermal conductive fillers dispersed therein. The nano-thermal conductive fillers are selected from at least one of boron nitride, alumina, or nano-graphene, and have a particle size of 10 nm to 100 nm. The thermal conductivity of the inner insulation layer is ≥0.8 W / (m·K), and the volume resistivity is ≥1×10⁻⁶. 16 Ω·cm, with a thickness of 0.4mm to 0.6mm.

[0011] In one embodiment of this application, the outer protective layer is made of either thermoplastic polyurethane or modified polyethylene terephthalate, with an elongation at break ≥400% and a thickness of 0.5mm to 0.8mm; and the outer surface of the outer protective layer is provided with at least two heat dissipation grooves extending along the axial direction of the conductor, the bottom of the heat dissipation grooves being a rounded transition with a radius R ≥0.1mm.

[0012] In one embodiment of this application, the relative permittivity of the inner insulating layer is 3.3 to 3.7, the relative permittivity of the outer protective layer is 2.2 to 2.6, and the ratio of the permittivity of the inner insulating layer to that of the outer protective layer is ≥1.3.

[0013] In one embodiment of this application, the conductor is either a tin-plated copper conductor or a silver-copper alloy conductor, and its outer surface roughness Ra ≤ 0.4 μm.

[0014] A method for manufacturing the aforementioned anti-leakage double-layer protective wire includes the following steps: Step S1: Provide a conductor and clean and roughness control the outer surface of the conductor so that its surface roughness Ra≤0.4μm; Step S2: Using a double-layer co-extrusion process, an inner insulation layer and an outer protective layer are simultaneously formed on the outer surface of the conductor; Step S3: When the inner insulating layer and the outer protective layer are in a molten state, a tensile force along the conductor axis is applied to the inner insulating layer to orient its molecular chains along the axial direction; at the same time, a shear force along the conductor circumferential direction is applied to the outer protective layer to orient its molecular chains circumferentially. Step S4: Cool and shape to obtain the anti-leakage double-layer protective wire.

[0015] In one embodiment of this application, steps S2 and S3 are performed simultaneously through a double-layer co-extrusion process. While forming the inner insulating layer and the outer protective layer, a transition adhesive layer is co-extruded between them. The material of the transition adhesive layer is either maleic anhydride-grafted polyolefin or ethylene-vinyl acetate copolymer.

[0016] In one embodiment of this application, the axial stretching ratio in step S4 is 1.2:1 to 1.8:1, and the stretching temperature is controlled within the range of 10°C above the softening point of the inner insulating layer material to 10°C below the heat distortion temperature of the outer protective layer material.

[0017] The advantages of this invention compared to existing technologies are: (1) The axial orientation of the molecular chains in the inner insulating layer is beneficial for withstanding the axial stress generated by the thermal expansion of the conductor and improving the axial dielectric strength; the circumferential orientation of the molecular chains in the outer protective layer enhances the radial resistance to voltage and wear. Combined with the gradient distribution of dielectric constant with high inner and low outer, the radial electric field can be effectively homogenized, the electric field concentration and space charge injection at the interface can be suppressed, and the ability to resist partial discharge and tracking can be fundamentally improved.

[0018] (2) High thermal conductivity nanofiller is added to the inner insulation layer, and combined with the axial heat dissipation groove design of the outer protective layer, a highly efficient heat conduction path from the inside to the outside is constructed, which significantly reduces the operating temperature of the conductor. The arc-shaped groove bottom design avoids stress concentration, ensuring excellent heat dissipation without significantly weakening the mechanical strength of the outer protective layer.

[0019] (3) By setting a transition adhesive layer with a specific thickness and peel strength, the tight bonding between the inner and outer layers is ensured under thermal, electrical, and mechanical stress, preventing delamination. The low roughness treatment of the conductor surface reduces microscopic defects and lowers the corona initiation voltage.

[0020] (4) The manufacturing method combines "axial stretching" and "circumferential shearing" to achieve orthogonal orientation of inner and outer molecular chains in one go and continuously, and has high compatibility with existing production lines.

[0021] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a perspective view of a double-layer protective wire for leakage protection according to an embodiment of the present invention; Figure 2 This is a front view of a double-layer protective wire with leakage protection according to an embodiment of the present invention; Figure 3 This is a front view of a double-layer protective wire with leakage protection according to an embodiment of the present invention; Figure 4 This is a rear view of a double-layer protective wire with leakage protection according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a double-layer protective wire for leakage protection in one embodiment of the present invention. Figure 1 ; Figure 6 This is a schematic diagram of the structure of a double-layer protective wire for leakage protection in one embodiment of the present invention. Figure 2 ; Figure 7 This is a process flow diagram of a method for manufacturing a double-layer protective wire with leakage protection according to an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached figures: 1. Conductor; 2. Inner insulation layer; 3. Outer protective layer; 31. Heat dissipation groove; 4. Transition adhesive layer. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] like Figures 1 to 7As shown in the figure, an anti-leakage double-layer protective wire according to an embodiment of the present invention includes a conductor 1, an inner insulation layer 2, and an outer protective layer 3 arranged coaxially from the inside to the outside. In some preferred embodiments, a transition adhesive layer 4 may be added between the inner insulation layer 2 and the outer protective layer 3. The outer surface of the outer protective layer 3 may be further processed with heat dissipation grooves 31.

[0027] In one embodiment of this application, conductor 1 is the conductive core of the wire and is typically made of a highly conductive metallic material. In this invention, conductor 1 is preferably a tin-plated copper conductor or a silver-copper alloy conductor. The tin plating layer prevents oxidation of the copper conductor and improves solderability; the silver-copper alloy maintains good conductivity while possessing higher strength and heat resistance. The outer surface condition of conductor 1 is crucial, and its roughness must be controlled within the range of Ra ≤ 0.4 μm. To achieve this requirement, the drawn copper or alloy rod needs to be precision polished or a final drawing process using an ultra-smooth die is required. A smooth conductor 1 surface eliminates microscopic sharpness and burrs, which are the starting points for local electric field concentration and corona discharge. Lower surface roughness means fewer microscopic defects, thereby effectively increasing the partial discharge initiation voltage when voltage is applied, reducing electrical damage to the insulating material at the source.

[0028] In one embodiment of this application, the inner insulation layer 2 is the first insulating barrier directly covering the outer surface of the conductor 1. Its main function is to withstand the working voltage between the conductor 1 and the outside, and it has excellent electrical insulation performance and long-term thermal stability.

[0029] The inner insulation layer 2 uses cross-linked polyethylene as the matrix material. Cross-linked polyethylene is produced by chemically or irradiating linear polyethylene molecular chains to form a three-dimensional network structure. Its heat resistance, mechanical strength, resistance to environmental stress cracking, and dimensional stability are significantly superior to ordinary polyethylene, making it particularly suitable for wiring applications requiring high long-term reliability. Within this matrix, nano-thermal conductive fillers are uniformly dispersed. These fillers are selected from one or more combinations of boron nitride, alumina, or nano-graphene. Their particle size is controlled between 10 and 100 nanometers. Nanoscale fillers minimize the negative impact on the insulation performance of the matrix, while their high thermal conductivity allows for the construction of efficient heat conduction pathways within the insulation layer. For example, sheet-like boron nitride or nano-graphene may undergo directional alignment during the orientation process, further enhancing thermal conductivity along specific directions.

[0030] A key structural feature of the inner insulation layer 2 is that its polymer chains (including polyethylene matrix segments) are mainly oriented along the axial direction of the conductor 1 (i.e., the length direction of the wire). The axial orientation of the molecular chains gives the polymer material higher tensile strength and modulus in the axial direction, which can better resist the axial stress caused by the thermal expansion and contraction of the conductor 1 and reduce the generation of micro-cracks in the insulation layer caused by repeated stress.

[0031] The thickness of the inner insulation layer 2 is designed to be between 0.4 mm and 0.6 mm to balance insulation performance with the overall outer diameter of the wire. Its volume resistivity is not less than 1×10⁻⁶. 16 The thermal conductivity is Ω·cm, ensuring excellent insulation performance. Its thermal conductivity is not less than 0.8 W / (m·K), thanks to the addition of nano-thermal conductive fillers, which help to rapidly conduct the Joule heat generated during conductor 1's operation outwards. Its relative permittivity is designed to be in the high range of 3.3 to 3.7.

[0032] In one embodiment of this application, the outer protective layer 3 covers the outer surface of the inner insulation layer 2 and serves as the first physical defense against external mechanical damage and environmental erosion (such as moisture and chemicals) for the wire. At the same time, it also performs some insulation functions.

[0033] The outer protective layer 3 is made of a material with high toughness and wear resistance, such as thermoplastic polyurethane or modified polyethylene terephthalate. Thermoplastic polyurethane has excellent elasticity, wear resistance and low temperature resistance; modified PET (such as PETG) has high transparency, good rigidity and impact resistance, so that the outer protective layer 3 is not easy to crack when the wire is laid and bent.

[0034] The core structural feature of the outer protective layer 3 is that its polymer chains are primarily oriented along the circumference of the conductor 1 (i.e., the direction surrounding the wire). This circumferential orientation is achieved by applying circumferential shear force to the outer melt during manufacturing. This circumferential orientation gives the outer protective layer 3 stronger resistance to external compression and scratches in the radial direction (i.e., the thickness direction), improving the durability of its mechanical protective properties. Its relative permittivity is designed to be in the lower range of 2.2 to 2.6.

[0035] On the outermost surface of the outer protective layer 3, at least two heat dissipation grooves 31 extending along the axial direction of the conductor 1 are provided. These grooves are not formed by subsequent cutting, but are formed in one step during extrusion molding using a mold with corresponding raised structures or a subsequent embossing process. The presence of the grooves significantly increases the heat dissipation area of ​​the outer surface of the wire. Of particular importance is that the bottom of the grooves is designed with a rounded transition, and the radius of the rounded arc R is not less than 0.1 mm. This smooth groove bottom geometry can effectively avoid sharp concave corners becoming stress concentration points, preventing cracks from initiating and propagating from the bottom of the groove when the wire is repeatedly bent or subjected to external pressure, thereby improving heat dissipation capacity while ensuring the mechanical integrity of the outer protective layer 3.

[0036] The outer protective layer 3 has a thickness between 0.5 mm and 0.8 mm to ensure sufficient mechanical protection. Its relative permittivity is lower than that of the inner insulating layer 2.

[0037] In one embodiment of this application, the relative permittivity (εinner) of the inner insulating layer 2 is set to be higher than that of the outer protective layer 3 (εouter), forming a radial "higher inner, lower outer" dielectric constant gradient. The ratio of the two (εinner / εouter) is not less than 1.3, preferably between 1.3 and 1.7.

[0038] In a homogeneous multilayer dielectric, the distribution of electric field intensity (E) is inversely proportional to the dielectric constant (ε) (E∝1 / ε). In the structure of this invention, since εinner > εouter, according to the principle of continuous electric displacement, the electric field intensity is relatively low in the inner insulating layer 2 and relatively high in the outer protective layer 3. This distribution is optimized by combining the "inner axial and outer circumferential" molecular chain orientation: the axial orientation of the inner layer molecular chains may be advantageous in withstanding the axial electric field component, while the outer layer, although with a slightly higher electric field intensity, has enhanced radial dielectric strength due to its circumferential orientation. More importantly, this gradual dielectric constant distribution avoids abrupt changes in dielectric constant at the interface between the inner and outer layers, thereby smoothing the electric field distribution and significantly suppressing electric field concentration at the interface. Electric field concentration is the primary cause of space charge injection, accumulation, and ultimately, partial discharge and electric tree growth. Therefore, this "high inside and low outside" dielectric constant gradient, combined with a specific molecular chain orientation, can physically "flatten" the electric field lines and reduce weak points in the insulation layer. This is one of the core mechanisms by which this invention improves the anti-leakage performance.

[0039] In one embodiment of this application, in order to ensure a tight bond between the inner insulation layer 2 and the outer protective layer 3 under long-term thermal, electrical and mechanical stress, and to prevent interlayer separation (delamination) caused by differences in the thermal expansion coefficients of the materials or external forces, a transition adhesive layer 4 can be provided between the two.

[0040] The material of the transition adhesive layer 4 needs to have good compatibility and adhesion with both the inner and outer layers. Maleic anhydride-grafted polyolefins (such as POE-g-MAH) or ethylene-vinyl acetate copolymers are usually selected. These materials contain polar groups or flexible segments, which can form physical entanglement or chemical bonding with the inner and outer layer materials, acting as "molecular bridges".

[0041] The thickness of the transition adhesive layer 4 is very thin, typically between 0.02 mm and 0.10 mm, to ensure effective adhesion without excessively increasing the overall thickness. Its adhesive strength is a key indicator; the T-peel strength, measured according to GB / T 2791-1995, should not be less than 2.5 N / mm. This strength ensures that the two insulation layers can still function as a unified whole in harsh environments, without delamination causing air gaps. Air gaps are breeding grounds for partial discharge, which drastically reduces the overall withstand voltage level of the insulation system.

[0042] Manufacturing method of double-layer protective cloth wire with leakage current protection: Step S1: Conductor pretreatment A suitable copper or alloy rod is provided, and a conductor 1 of the required diameter is produced through a continuous drawing and undrawing process. Then, the outer surface of conductor 1 undergoes fine cleaning (e.g., ultrasonic cleaning to remove oil) and roughness control treatment. Roughness control can be achieved through precision die sizing drawing or non-contact laser polishing, ultimately ensuring that the arithmetic mean deviation Ra value of the outer surface profile of conductor 1 is no greater than 0.4 micrometers. The treated conductor is kept clean and dry before proceeding to the extrusion process.

[0043] Step S2: Simultaneous co-extrusion to form a composite preform This step employs a two-layer co-extrusion process. During the movement of conductor 1, an inner insulation layer 2 and an outer protective layer 3 are simultaneously extruded onto its outer surface. Specifically, cross-linked polyethylene granules (inner layer material) mixed with nano-thermal conductive fillers and thermoplastic polyurethane or modified PET granules (outer layer material) are fed into two independent extruders. The two extruders melt, plasticize, and homogenize the materials, then convey the melt to a two-layer co-extrusion die. This die has inner and outer flow channels; the inner flow channel surrounds conductor 1, and the outer flow channel surrounds the inner flow channel. In the confluence area of ​​the die, the inner melt first coats conductor 1 to form the preform of the inner insulation layer 2. Immediately afterwards, the outer melt coats the inner preform to form the preform of the outer protective layer 3. The two layers combine at the die exit into a single, still molten composite preform.

[0044] Optionally, a transitional adhesive layer 4 is formed: If a transitional adhesive layer 4 is required, a three-layer co-extrusion die and a third extruder are needed. The third extruder provides the adhesive layer material (such as POE-g-MAH). Inside the die, the three melt layers (inner layer / adhesive layer / outer layer) are stacked sequentially in the designed order. After extrusion from the die, a four-layer composite structure is formed from the inside out as "inner insulation layer preform / transitional adhesive layer preform / outer protective layer preform".

[0045] Step S3: Differentiated molecular chain orientation treatment After the composite preform formed in step S2 is extruded from the die, its temperature is still above the melting temperature range of each layer of material, and the polymer chain segments have sufficient mobility. At this time, a force field in a specific direction is applied to the composite preform to induce the molecular chains to align along a predetermined direction.

[0046] Axial orientation is achieved by applying an axial tensile force to the inner insulation layer 2 through differential traction of the wire. Specifically, two sets of traction wheels are set up, with the linear velocity V2 of the rear traction wheel being greater than the linear velocity V1 of the front traction wheel or the die exit. The ratio V2 / V1 is the stretching ratio, which is controlled to be between 1.2:1 and 1.8:1 in this invention. This tensile force mainly acts on the entire wire, but because the inner insulation layer 2 is in close contact with the conductor 1 and its material (cross-linked polyethylene precursor) is in a suitable state at this temperature, the axial tensile force can effectively cause the polymer molecular chains in the inner insulation layer 2 to untangle and stretch along the wire axis (stretching direction), forming a preferred axial orientation.

[0047] Applying circumferential shear force to the outer protective layer 3 to achieve circumferential orientation: This operation can be performed simultaneously with axial stretching. An effective way to achieve circumferential shear is to integrate a high-speed rotating die lip or rotating sleeve at the outer runner outlet of the extrusion die. When the outer melt (outer protective layer material) flows through this rotating component, a strong circumferential shear force is generated between the inner wall of the component and the melt. This shear flow field forces the polymer chains in the outer protective layer 3 melt to align along the shear direction, i.e., the circumferential direction of the wire. Another alternative is to use a specially designed static mixer capable of generating circumferential circulation installed inside the die, or to use a rotating cooling and shaping sleeve in a subsequent process.

[0048] Process Co-control: Temperature control in this step is crucial and is called the stretching temperature. This temperature must be controlled at 10°C above the softening point of the inner insulation material (such as polyethylene) to ensure sufficient molecular chain mobility to respond to axial stretching; simultaneously, this temperature must be controlled at 10°C below the heat distortion temperature of the outer protective layer material (such as TPU) to ensure that the outer layer material can undergo molecular chain orientation under circumferential shear without excessive deformation or breakage due to overheating. This temperature window ensures that the two orientation processes can proceed synergistically.

[0049] Step S4: Cooling, Shaping, and Post-processing The oriented composite wires immediately enter the cooling and setting stage, typically through a cooling water tank filled with cooling water (room temperature or low temperature). The purpose of rapid cooling is to "freeze" and fix the oriented molecular chain structure, ensuring it maintains this optimized structure during subsequent use. After cooling and setting, the wire dimensions are stable.

[0050] Next, the outer protective layer 3 of the wire can be post-processed to form a heat dissipation groove 31. The wire is passed through a pair of embossing wheels, at least one of which has raised stripes etched on it. As the wire passes through, the embossing wheels imprint axially extending grooves on their surfaces. By controlling the cross-sectional shape of the raised stripes on the embossing wheels, it can be ensured that the bottom of the imprinted heat dissipation groove 31 has a rounded transition, and the radius of the rounded arc R is ≥ 0.1 mm.

[0051] Finally, the wire is inspected for pinholes online using a spark testing machine. If it passes the inspection, it is neatly wound up by a winding device to obtain the finished anti-leakage double-layer protective wire of this invention. If the inner insulation material is silane cross-linked polyethylene, it needs to be placed in a steam room or hot water tank for cross-linking treatment after winding to form the final three-dimensional network structure.

[0052] Obviously, the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A double-layer protective electrical wire with leakage protection, characterized in that, It includes a conductor (1), an inner insulation layer (2), and an outer protective layer (3); The inner insulating layer (2) tightly covers the outer surface of the conductor (1); The outer protective layer (3) tightly covers the outer surface of the inner insulating layer (2); The molecular chains of the inner insulating layer (2) are oriented along the axial direction of the conductor (1), and the molecular chains of the outer protective layer (3) are oriented along the circumferential direction of the conductor (1). The relative permittivity of the inner insulating layer (2) is higher than that of the outer protective layer (3), resulting in a radially distributed permittivity with a higher inner permittivity and a lower outer permittivity.

2. The anti-leakage double-layer protective wire according to claim 1, characterized in that, A transition adhesive layer (4) is provided between the inner insulation layer (2) and the outer protective layer (3). The thickness of the transition adhesive layer (4) is 0.02 mm to 0.10 mm, and the T-type peel strength measured with reference to GB / T 2791-1995 is ≥2.5 N / mm.

3. The anti-leakage double-layer protective electrical wire according to claim 1, characterized in that, The inner insulation layer (2) is composed of a cross-linked polyethylene matrix and nano-thermal conductive fillers dispersed therein. The nano-thermal conductive fillers are selected from at least one of boron nitride, alumina, or nano-graphene, and have a particle size of 10 nm to 100 nm. The thermal conductivity of the inner insulation layer (2) is ≥0.8 W / (m·K), and the volume resistivity is ≥1×10⁻⁶. 16 Ω·cm, with a thickness of 0.4mm to 0.6mm.

4. The anti-leakage double-layer protective wire according to claim 1, characterized in that, The outer protective layer (3) is made of either thermoplastic polyurethane or modified polyethylene terephthalate, with an elongation at break ≥400% and a thickness of 0.5mm to 0.8mm; and the outer surface of the outer protective layer (3) is provided with at least two heat dissipation grooves (31) extending along the axial direction of the conductor (1), the bottom of the heat dissipation grooves (31) being a rounded transition with a radius R ≥0.1mm.

5. The anti-leakage double-layer protective wire according to claim 1, characterized in that, The relative permittivity of the inner insulating layer (2) is 3.3 to 3.7, the relative permittivity of the outer protective layer (3) is 2.2 to 2.6, and the ratio of the permittivity of the inner insulating layer (2) to that of the outer protective layer (3) is ≥1.

3.

6. The anti-leakage double-layer protective wire according to claim 1, characterized in that, The conductor (1) is either a tin-plated copper conductor or a silver-copper alloy conductor, and its outer surface roughness Ra≤0.4μm.

7. A method for manufacturing the anti-leakage double-layer protective cloth wire according to any one of claims 1 to 6, characterized in that, Includes the following steps: Step S1: Provide a conductor (1) and clean and roughen the outer surface of the conductor (1) so that its surface roughness Ra≤0.4μm; Step S2: Using a double-layer co-extrusion process, an inner insulation layer (2) and an outer protective layer (3) are simultaneously formed on the outer surface of the conductor (1). Step S3: When the inner insulating layer (2) and the outer protective layer (3) are in a molten state, a tensile force along the conductor axis is applied to the inner insulating layer (2) to orient its molecular chains along the axial direction; at the same time, a shear force along the conductor circumferential direction is applied to the outer protective layer (3) to orient its molecular chains circumferentially. Step S4: Cool and shape to obtain the anti-leakage double-layer protective wire.

8. The manufacturing method according to claim 7, characterized in that, Steps S2 and S3 are carried out simultaneously through a double-layer co-extrusion process. While forming the inner insulating layer (2) and the outer protective layer (3), a transition adhesive layer (4) is co-extruded between them. The material of the transition adhesive layer (4) is either maleic anhydride grafted polyolefin or ethylene-vinyl acetate copolymer.

9. The manufacturing method according to claim 7, characterized in that, In step S4, the axial stretching ratio is 1.2:1 to 1.8:1, and the stretching temperature is controlled within the range of 10°C above the softening point of the inner insulating layer material to 10°C below the heat distortion temperature of the outer protective layer material.

Images