High-performance anti-interference low-voltage cable and preparation process thereof

Abstract

The invention discloses a high-performance anti-interference low-voltage cable, which relates to the technical field of power transmission equipment, and is technically characterized by comprising a conductor core, an insulating layer, a shielding layer, a buffer layer and an outer sheath which are sequentially and coaxially arranged from inside to outside, the conductor core is made of a plurality of strands of tinned copper wires through a double stranding process of bunch stranding and compound stranding; the insulating layer coats the outer side of the conductor core; the shielding layer is of a double-layer structure and comprises an inner-layer aluminum-plastic composite belt and an outer-layer tinned copper wire braid layer, and an aluminum layer of the aluminum-plastic composite belt faces the inner side and is in equipotential connection with the conductor core. A layer of conductive carbon fiber cloth is wrapped on the outer side of the braid layer; the buffer layer is filled between the shielding layer and the outer sheath, and a plurality of aramid fiber reinforcing ribs are uniformly embedded in the buffer layer along the axial direction of the cable; the thickness of the outer sheath is made of a weather-resistant polyvinyl chloride material added with an ultraviolet light absorber and an anti-aging agent, and the inner surface of the outer sheath is provided with an anti-skid groove. And a nano montmorillonite filler is uniformly dispersed in the outer sheath.

Description

Technical Field

[0001] This invention relates to the field of power transmission equipment technology, specifically to a high-performance anti-interference low-voltage cable and its manufacturing process. Background Technology

[0002] Low-voltage cables, as a core component of power transmission systems, are widely used in various fields such as building engineering, industrial automation, new energy photovoltaic power plants, smart grids, and underground utility tunnels. Their performance directly determines the stability, safety, and service life of power transmission. With the rapid development of emerging fields, higher requirements are being placed on the environmental adaptability, anti-interference capabilities, and mechanical properties of low-voltage cables. However, existing low-voltage cables still have many technical shortcomings:

[0003] Insufficient electromagnetic interference resistance: Traditional low-voltage cables mostly use a single aluminum-plastic composite tape or a single tinned copper wire braid as the shielding layer, which can only specifically resist electromagnetic interference in a specific frequency band, and the shielding effect across the entire frequency band is poor; moreover, there is a potential difference between the shielding layer and the conductor core, which generates additional electric field interference, further reducing the shielding stability and failing to meet the usage requirements of strong electromagnetic interference environments such as industrial automation workshops and new energy equipment.

[0004] Weak mechanical properties: The conductor core of existing cables mostly adopts a simple stranded structure with low tensile strength, which makes them prone to breakage during laying and traction; the buffer layer only undertakes the single function of buffering impact and lacks a targeted reinforcement structure, resulting in poor fatigue resistance of the cable and easy occurrence of problems such as interlayer peeling and loose structure after long-term use.

[0005] Poor environmental adaptability: The outer sheath is mostly made of ordinary weather-resistant materials, which have limited wear resistance and chemical corrosion resistance. It is prone to aging and cracking when laid in the open air or in damp underground environments. The waterproof sealing performance is insufficient, and leakage accidents are prone to occur in damp environments. The service life is usually less than 10 years.

[0006] Lack of equipotential bonding design: Existing technologies rarely pay attention to the potential matching between the shielding layer and the conductor core, and do not set up a dedicated equipotential bonding structure. This results in a potential difference between the shielding layer and the conductor core, which not only interferes with the electromagnetic shielding effect, but may also cause partial discharge and affect the safety of cable operation.

[0007] Therefore, developing a high-performance low-voltage cable that integrates full-band anti-interference, high mechanical strength, strong environmental adaptability, and stable equipotential bonding is key to solving the pain points of existing technologies. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-performance anti-interference low-voltage cable. By optimizing the overall cable structure, innovating the equipotential bonding method, and improving the material formula, it achieves the technical effects of full-band electromagnetic interference resistance, high tensile strength and fatigue resistance, and strong environmental adaptability, thus meeting the usage requirements of special environments.

[0009] The above-mentioned technical objective of the present invention is achieved by the following technical solution:

[0010] A high-performance anti-interference low-voltage cable includes a conductor core, an insulation layer, a shielding layer, a buffer layer, and an outer sheath arranged coaxially from the inside to the outside.

[0011] The conductor core is made of multiple strands of tin-plated copper wire through a double stranding process of bundle stranding and re-strand stranding;

[0012] The insulating layer covers the outside of the conductor core and has a thickness of 0.8-1.2 mm. It is made of modified polyolefin composite material, which is made by mixing polyolefin resin, nano silica, flame retardant and antioxidant in a mass ratio of 80:10:6:4.

[0013] The shielding layer has a double-layer structure, including an inner aluminum-plastic composite strip and an outer tin-plated copper wire braided layer. The thickness of the aluminum-plastic composite strip is 0.15-0.2mm, the overlap rate is not less than 25%, and the aluminum layer of the aluminum-plastic composite strip faces inward and forms an equipotential connection with the conductor core.

[0014] The braiding density of the tin-plated copper wire braided layer is not less than 90%, the diameter of the tin-plated copper wire is 0.12-0.18mm, and a layer of conductive carbon fiber cloth is wrapped around the outside of the braided layer. The areal density of the conductive carbon fiber cloth is 80-120g / m³. 2 It is used to enhance the attenuation effect of high-frequency electromagnetic shielding and improve the overall structural strength of the shielding layer;

[0015] The buffer layer is filled between the shielding layer and the outer sheath, with a thickness of 0.5-0.8 mm. It is made of flame-retardant elastomer material, with an oxygen index of not less than 32% and a Shore hardness of 55-65A.

[0016] The buffer layer is uniformly embedded with several aramid fiber reinforcing ribs along the cable axis. The diameter of the aramid fiber reinforcing ribs is 0.3-0.5mm, and the spacing between adjacent reinforcing ribs is 10-15mm, which is used to improve the tensile strength and fatigue resistance of the cable.

[0017] The outer sheath has a thickness of 1.0-1.5 mm, calculated by weight. It is made of weather-resistant polyvinyl chloride (PVC) material containing 0.3-0.8 parts of UV absorber and 0.2-0.6 parts of anti-aging agent, with the weather-resistant PVC material comprising 100 parts. The inner surface of the outer sheath has anti-slip grooves. Its weather resistance rating reaches UVB3 or higher, and its temperature resistance range is -40℃ to 105℃.

[0018] The outer sheath also contains uniformly dispersed nano-montmorillonite filler, the amount of which is 3-5% of the mass of the weather-resistant polyvinyl chloride material, used to improve the wear resistance and chemical corrosion resistance of the outer sheath.

[0019] Furthermore, the diameter of each tin-plated copper wire is 0.1-0.3 mm, the stranding pitch is 8-10 times the diameter of each copper wire, and the double stranding pitch is 12-15 times the diameter of the conductor core.

[0020] Furthermore, the modified polyolefin composite material has a breakdown field strength ≥25kV / mm and a long-term service temperature of up to 105℃.

[0021] Furthermore, the depth of the anti-slip groove is 0.2-0.3mm, and the spacing is 5-8mm.

[0022] The outer surface of the outer sheath is frosted.

[0023] Furthermore, the cable has a waterproof rating of IP67 or higher, a tensile strength of ≥15kN / mm², and a bending radius of no more than 7 times the cable diameter.

[0024] Furthermore, all materials used in the cable comply with RoHS standards, and the flame retardant performance reaches UL94V-0 level.

[0025] Furthermore, the conductive carbon fiber cloth and the tin-plated copper wire braided layer are bonded and fixed together by conductive adhesive, the thickness of which is 0.05-0.1mm.

[0026] Furthermore, the aramid fiber reinforced rib has a breaking strength ≥2800MPa and an elastic modulus ≥130GPa.

[0027] Furthermore, the nano-montmorillonite filler is organically modified montmorillonite with an interlayer spacing of 2-5 nm.

[0028] Furthermore, the plastic layer of the aluminum-plastic composite strip is made of polyethylene material with a thickness of 0.08-0.12mm, and the aluminum layer has a thickness of 0.07-0.08mm.

[0029] Furthermore, the flame-retardant elastomer material is a halogen-free flame-retardant thermoplastic elastomer with a tensile strength ≥10MPa and an elongation at break ≥300%.

[0030] Furthermore, the equipotential connection between the aluminum layer and the conductor core of the aluminum-plastic composite tape is achieved through the following structure: 3-5 annular conductive grooves are uniformly opened along the circumference on the outer surface of the insulating layer. The conductive grooves are filled with conductive silver paste. The aluminum layer of the aluminum-plastic composite tape is attached to the conductive silver paste and is in close contact with the conductive silver paste. The conductive silver paste is connected to the conductor core through the pre-set conductive through holes on the insulating layer to form a stable equipotential path.

[0031] Furthermore, the diameter of the conductive via is 0.1-0.2 mm, and it is uniformly distributed along the circumference of the insulating layer. The spacing between adjacent conductive vias is 8-12 mm. The conductive vias are filled with conductive adhesive to achieve reliable conduction between the conductive silver paste and the conductor core.

[0032] Furthermore, the equipotential connection between the aluminum layer of the aluminum-plastic composite tape and the conductor core is achieved through axial conductive ribs: the axial conductive ribs are arranged along the length of the cable, with a quantity of 4-6 ribs, evenly distributed between the insulation layer and the aluminum-plastic composite tape. One end of the axial conductive rib is welded and fixed to the conductor core, and the other end is welded and fixed to the aluminum layer of the aluminum-plastic composite tape. The diameter of the axial conductive rib is 0.2-0.3mm, and it is made of silver-plated copper wire.

[0033] This invention also provides a manufacturing process for a high-performance anti-interference low-voltage cable, comprising the following steps:

[0034] S1. Conductor core preparation: Select tin-plated copper wire with a diameter of 0.1-0.3mm, first bundle it through a bundling machine, and control the bundling pitch to 8-10 times the diameter of each copper wire. Then, re-twist it through a re-twist machine, and control the re-twist pitch to 12-15 times the conductor core diameter to make the conductor core.

[0035] S2. Insulation layer coating: The modified polyolefin composite material is fed into the extruder, the extrusion temperature is controlled at 160-180℃, the extrusion speed is 5-8m / min, and the insulation layer is uniformly coated on the outside of the conductor core. After coating, it is cooled and shaped by cold water.

[0036] S3. Shielding layer covering: If an equipotential bonding structure of annular conductive groove + conductive silver paste is adopted, first process annular conductive groove on the outside of the insulation layer and fill it with conductive silver paste and conductive through holes; if an equipotential bonding structure of axial conductive rib is adopted, first weld and fix the axial conductive rib to the conductor core and lay it out along the circumference of the insulation layer; then wrap aluminum-plastic composite tape on the outside of the insulation layer, ensuring that the overlap rate is not less than 25% and that the aluminum layer faces inward and is in close contact with the conductive silver paste or axial conductive rib, then braid tin-plated copper wire with a braiding machine, controlling the braiding density to be not less than 90%, then coat the outside of the braided layer with conductive adhesive and wrap it with conductive carbon fiber cloth, and compact it to form a complete shielding layer;

[0037] S4. Buffer layer filling: Flame-retardant elastomer material and aramid fiber reinforcement are simultaneously extruded onto the outside of the shielding layer using an extruder. The thickness of the buffer layer is controlled to be 0.5-0.8mm to ensure that the aramid fiber reinforcement is evenly distributed and without deviation. After filling, it is compacted and shaped.

[0038] S5. Outer sheath covering: Weather-resistant polyvinyl chloride material is fed into an extruder at an extrusion temperature of 150-170℃ and an extrusion speed of 4-6m / min. An outer sheath is covered on the outside of the buffer layer. During the covering process, anti-slip grooves are pressed out by a mold. Finally, after cooling, pulling, and winding, the finished cable is produced.

[0039] It should be noted that the overlap rate referred to in this invention is the percentage of the width of the overlapping portion of adjacent aluminum-plastic composite tapes to the width of a single aluminum-plastic composite tape; the braiding density is the percentage of the projected area of ​​the tin-plated copper wire braided layer on a cross-section perpendicular to the cable axis to the total area of ​​that cross-section.

[0040] The formula for calculating the overlap rate is:

[0041] Overlap rate = (W0 / W1) × 100%

[0042] In the formula, W1 is the overlap width of two adjacent aluminum-plastic composite strips (i.e., the radial width of the overlapping area after wrapping), and the unit is mm; W0 is the nominal width of a single aluminum-plastic composite strip, and the unit is mm.

[0043] The formula for calculating braiding density is: Braiding density = (S0 / S1) × 100%, where S1 is the total projected area of ​​the tin-plated copper wire braid layer on a cross-section perpendicular to the cable axis, and the unit is mm. 2 S0 represents the total area of ​​the cross-section (i.e., the cross-sectional area of ​​the region covered by the braided layer), and the unit is mm. 2 With a braiding density of no less than 90%, it can ensure that external electromagnetic interference is effectively shielded, while reducing the outward radiation of internal signals, making it suitable for cable scenarios with high electromagnetic shielding requirements.

[0044] Compared with the prior art, the present invention has the following advantages:

[0045] 1. It adopts a three-layer composite shielding structure of "aluminum-plastic composite tape + tinned copper wire braided layer + conductive carbon fiber cloth" to comprehensively resist low-frequency and high-frequency electromagnetic interference. Combined with an innovative equipotential connection structure, it eliminates the potential difference between the shielding layer and the conductor core, avoids additional electric field interference, and has a shielding attenuation of ≥95dB, which is far superior to traditional cables (shielding attenuation is usually ≤80dB), and can adapt to strong electromagnetic interference environments.

[0046] 2. The conductor core adopts a double stranding process, and the buffer layer is embedded with aramid fiber reinforcement, which increases the tensile strength of the cable to more than 15kN / mm², reduces the bending radius to less than 7 times the cable diameter, and significantly improves fatigue resistance; the anti-slip groove on the inner surface of the outer sheath enhances the interlayer bonding force, avoids interlayer peeling, and extends the service life of the cable to more than 15 years.

[0047] 3. Strong environmental adaptability: The outer sheath is made of weather-resistant polyvinyl chloride material modified with nano-montmorillonite, combined with the addition of ultraviolet absorbers and anti-aging agents, which makes it wear-resistant, chemical corrosion-resistant and weather-resistant. The cable has a waterproof rating of IP67 and above, and a temperature range of -40℃ to 105℃. It can adapt to a variety of special environments such as high temperature, low temperature, humidity and open air, and has a wide range of applications.

[0048] 4. All materials used comply with RoHS standards, and the flame retardant performance reaches UL94V-0 level. They are halogen-free and low-smoke, which can reduce the release of toxic gases in the event of a fire. The equipotential bonding structure can also reduce the risk of partial discharge and improve the safety of cable operation.

[0049] 5. Both equipotential bonding methods are compatible with existing cable manufacturing processes, requiring no large-scale modification of production equipment and facilitating industrial mass production. Attached Figure Description

[0050] Figure 1 This is a cross-sectional view of the cable of the present invention;

[0051] Figure 2 This is a schematic diagram of the shielding layer in the cable structure of the present invention;

[0052] Figure 3 This is a schematic diagram of the outer sheath structure in the cable structure of the present invention;

[0053] Figure 4 This is a schematic diagram of the insulation layer structure of Method 1 in the cable structure of the present invention;

[0054] Figure 5 This is a schematic diagram of the insulation layer structure of Method 2 in the cable structure of the present invention.

[0055] Figure Labels

[0056] 1. Conductor core, 2. Insulation layer, 3. Shielding layer, 4. Aramid fiber reinforcing rib, 5. Buffer layer, 6. Outer sheath, 21. Conductive groove, 22. Conductive through hole, 23. Axial conductive rib, 31. Inner aluminum-plastic composite strip, 32. Outer tin-plated copper wire braided layer, 33. Conductive fiber cloth, 61. Anti-slip groove. Detailed Implementation

[0057] First, it should be noted that in different described embodiments, the same components are given the same reference numerals or the same component names. The disclosure contained throughout this specification can be applied semantically to the same components having the same reference numerals or the same component names. The location descriptions selected in the specification, such as upper, lower, lateral, etc., also refer to the directly described and illustrated figures and are semantically applied to the new location when the location changes.

[0058] A high-performance anti-interference low-voltage cable, such as Figure 1-5 As shown, the structure includes a conductor core 1, an insulating layer 2, a shielding layer 3, a buffer layer 5, and an outer sheath 6 arranged coaxially from the inside out. The structural and material designs are as follows:

[0059] 1. Conductor Core 1: Made of multiple strands of tin-plated copper wire using a double stranding process (bundling + re-stranding). Each strand of tin-plated copper wire is a TR-T2 type electrical grade tin-plated soft round copper wire with a diameter of 0.1-0.3mm. The bundled pitch is 8-10 times the diameter of each strand, and the re-stranding pitch is 12-15 times the diameter of the conductor core. The tin plating layer effectively prevents copper wire oxidation and improves conductivity stability; the double stranding structure significantly enhances the tensile strength and flexibility of the conductor core, preventing breakage during installation.

[0060] 2. Insulation Layer 2: Covering the outer side of the conductor core, with a thickness of 0.8-1.2mm, it is made of modified polyolefin composite material. This material is composed of polyolefin resin (specifically, random copolymer polypropylene resin of model PPR-CT100), nano silica (30nm hydrophilic nano silica of model VK-SP30), flame retardant (halogen-free phosphorus-nitrogen flame retardant of model FR-PP-01), and antioxidant (hindered phenolic antioxidant of model 1010) in a mass ratio of 80:10:6:4. Among them, the polyolefin resin provides basic insulation performance, nano silica improves the mechanical strength and wear resistance of the material, flame retardant enhances the flame retardant effect, and antioxidant delays the aging of the material. The modified material has a breakdown field strength ≥25kV / mm, a long-term operating temperature of up to 105℃, excellent insulation performance, and high temperature resistance.

[0061] 3. Shielding layer 3: Adopts a three-layer composite structure of "aluminum-plastic composite strip 31 + tin-plated copper wire braided layer 32 + conductive carbon fiber cloth 33" to achieve full-band electromagnetic interference resistance.

[0062] (1) Inner layer aluminum-plastic composite tape 31: The aluminum-plastic composite tape of model AL-PET-02 is selected, with a thickness of 0.15-0.2mm and an overlap rate of not less than 25%. The aluminum layer faces inward and forms an equipotential connection with the conductor core, which can effectively block low-frequency electromagnetic interference. The plastic layer of the aluminum-plastic composite tape is made of high-density polyethylene material of model HDPE-5000S with a thickness of 0.08-0.12mm and the aluminum layer thickness is 0.07-0.08mm, which takes into account both insulation protection and conductive shielding functions.

[0063] (2) Middle layer tin-plated copper wire braided layer 32: the braiding density is not less than 90%, the tin-plated copper wire is selected as TR-T2 electrical tin-plated soft round copper wire with a diameter of 0.12-0.18mm, which has a good shielding effect against high frequency electromagnetic interference; the tin plating layer can prevent copper wire oxidation and extend the service life of the shielding layer.

[0064] (3) Outer conductive carbon fiber cloth 33: Select conductive carbon fiber cloth of model T700-12K, wrap it around the outside of the braided layer, with a surface density of 80-120g / m², and bond it to the braided layer with conductive adhesive (two-component epoxy conductive adhesive of model EC-1000) (the thickness of conductive adhesive is 0.05-0.1mm). This not only further enhances the attenuation effect of high frequency electromagnetic shielding, but also improves the overall structural strength of the shielding layer and prevents the braided layer from becoming loose.

[0065] 4. Equipotential bonding structure: This invention provides two stable and reliable equipotential bonding implementation methods, which can be selected according to actual production needs:

[0066] Method 1: Annular conductive groove 21 + conductive silver paste + conductive through-hole structure 22

[0067] Three to five annular conductive grooves 21 are uniformly opened along the circumference on the outer surface of the insulating layer. The grooves are filled with conductive silver paste (high-temperature conductive silver paste of model AG-8830). Conductive through holes 22 are pre-set on the insulating layer 2. The diameter of the through holes is 0.1-0.2mm. They are uniformly distributed along the circumference of the insulating layer 2. The spacing between adjacent through holes is 8-12mm. The through holes are filled with conductive adhesive (two-component epoxy conductive adhesive of model EC-1000). The aluminum layer of the aluminum-plastic composite strip 31 is bonded to the conductive silver paste and is in close contact. The conductive silver paste is connected to the conductor core 1 through the conductive adhesive in the conductive through holes 21, forming a stable equipotential path and eliminating the potential difference between the shielding layer 3 and the conductor core 1.

[0068] Method 2: Axial conductive rib 23 welded structure

[0069] Four to six axial conductive ribs 23 are installed along the length of the cable, evenly distributed between the insulation layer 2 and the aluminum-plastic composite tape 31. The axial conductive ribs 23 are made of silver-plated soft round copper wire of model TR-T2-Ag, with a diameter of 0.2-0.3mm. One end is welded and fixed to the conductor core 1, and the other end is welded and fixed to the aluminum layer of the aluminum-plastic composite tape 31, directly realizing the conductive connection between the two and ensuring equipotentiality. This structure provides a reliable connection and does not affect the flexibility of the cable.

[0070] 5. Buffer Layer 5: Filled between the shielding layer 3 and the outer sheath 6, with a thickness of 0.5-0.8mm, made of flame-retardant elastomer material (oxygen index not less than 32%, Shore hardness 55-65A); preferably halogen-free flame-retardant thermoplastic elastomer of model TPE-EF80, with tensile strength ≥10MPa, elongation at break ≥300%, flame-retardant and environmentally friendly with excellent buffering performance. Several aramid fiber reinforcing ribs 4 (using Kevlar-49 aramid fiber, diameter 0.3-0.5mm, spacing between adjacent reinforcing ribs 10-15mm) are uniformly embedded along the cable axis within the buffer layer. The aramid fiber has a tensile strength ≥2800MPa and an elastic modulus ≥130GPa, which can significantly improve the tensile and fatigue resistance of the cable, preventing mechanical damage during cable laying and use.

[0071] 6. Outer Sheath 6: Thickness is 1.0-1.5mm. Calculated by weight, it uses 100 parts of weather-resistant PVC material (specifically, weather-resistant PVC cable material of model PVC-WH70) with 0.3-0.8 parts of UV absorber (benzotriazole UV absorber of model UV-531) and 0.2-0.6 parts of anti-aging agent (hindered phenolic anti-aging agent of model 1076). The weather resistance level reaches UVB3 or above, and the temperature range is -40℃ to 105℃, which can adapt to various harsh environments such as high temperature, low temperature, and open air. The outer sheath also uniformly disperses 3-5% (by weight) of 2-5 parts of nano-montmorillonite filler (preferably organic modified montmorillonite of model DK2, with a layer spacing of 2-5nm), which greatly improves the wear resistance and chemical corrosion resistance of the outer sheath.

[0072] The inner surface of the outer sheath 6 is provided with anti-slip grooves 61 (0.2-0.3mm deep, 5-8mm apart), which can enhance the bonding force with the buffer layer and prevent interlayer peeling; the outer surface is frosted to improve the anti-slip performance during the laying process and facilitate construction.

[0073] The manufacturing process of the high-performance anti-interference low-voltage cable of the present invention includes the following steps:

[0074] S1. Preparation of conductor core 1: Select tin-plated copper wire with a diameter of 0.1-0.3mm, first bundle it through a bundling machine (bundling pitch controlled at 8-10 times the diameter of each copper wire), and then re-twist it through a re-twist machine (re-twist pitch controlled at 12-15 times the diameter of the conductor core) to make the conductor core; control the twisting tension to be uniform during bundling and re-twist to ensure that the conductor core structure is compact.

[0075] S2, Insulation Layer 2 Coating: The modified polyolefin composite material (polyolefin resin, nano silica, flame retardant, and antioxidant mixed in a mass ratio of 80:10:6:4) is fed into an extruder. The extrusion temperature is controlled at 160-180℃, and the extrusion speed is 5-8m / min. The insulation layer 2 is uniformly coated on the outside of the conductor core. After coating, it is immediately cooled and shaped by cold water to ensure that the insulation layer 2 has a uniform thickness and is free of bubbles and cracks. If the equipotential bonding structure of Method 1 is adopted, after cooling and shaping, an annular conductive groove 21 needs to be processed on the outside of the insulation layer 2, and conductive through holes 22 need to be opened. The groove is filled with conductive silver paste, and the through holes are filled with conductive adhesive.

[0076] S3, Shielding layer 3 covering: Pre-treatment is performed according to the selected equipotential bonding method: If method one is used, the subsequent covering is performed directly; if method two is used, the axial conductive rib 23 is first welded and fixed to the conductor core 1, and evenly distributed along the circumference of the insulation layer 2; then aluminum-plastic composite tape 31 is wrapped around the outside of the insulation layer 2, ensuring that the overlap rate is not less than 25% and the aluminum layer faces inward, in close contact with the conductive silver paste (method one) or the axial conductive rib 23 (method two); then tin-plated copper wire is braided by a braiding machine, controlling the braiding density to be not less than 90%; then conductive adhesive is coated on the outside of the braided layer, and conductive carbon fiber cloth 33 is wrapped around it, and after compaction, a complete shielding layer 3 is formed.

[0077] S4. Filling the buffer layer 5: Simultaneously extrude the flame-retardant elastomer material and the aramid fiber reinforcing ribs 4 onto the outside of the shielding layer 3 using an extruder, controlling the thickness of the buffer layer 5 to be 0.5-0.8mm; during the extrusion process, ensure that the aramid fiber reinforcing ribs 4 are evenly distributed and without deviation, and compact and shape them after filling to enhance the bonding force between the buffer layer 5 and the shielding layer 3.

[0078] S5, Outer Sheath 6 Covering: Weather-resistant polyvinyl chloride material with added ultraviolet absorbers, anti-aging agents and nano montmorillonite fillers is put into an extruder, the extrusion temperature is 150-170℃, the extrusion speed is 4-6m / min, and the outer sheath 6 is covered on the outside of the buffer layer 5; during the covering process, anti-slip grooves 61 are pressed out by a mold, and finally cooled, pulled and wound up to make the finished cable.

[0079] Example 1: Equipotential bonding method using annular conductive groove + conductive silver paste + conductive through hole

[0080] A high-performance anti-interference low-voltage cable, such as Figure 1-5As shown, it includes a conductor core 1, an insulating layer 2, a shielding layer 3, a buffer layer 5, and an outer sheath 6 arranged coaxially from the inside out. The structure and parameters are as follows:

[0081] 1. Conductor core 1: It is made of multiple strands of tin-plated copper wire (model TR-T2) with a diameter of 0.2mm through a bundle stranding and re-stranding process. The bundle stranding pitch is 8 times the diameter of each copper wire, and the re-stranding pitch is 12 times the diameter of the conductor core.

[0082] 2. Insulation layer 2: 1.0 mm thick, modified polyolefin composite material is mixed in a mass ratio of 80:10:6:4 (80 parts of polyolefin resin PPR-CT100, 10 parts of nano silica VK-SP30, 6 parts of flame retardant FR-PP-01, and 4 parts of antioxidant 1010); 3 annular conductive grooves 21 are opened on the outer surface of insulation layer 2 and filled with conductive silver paste AG-8830; 8 conductive through holes 22 (0.15 mm in diameter, 10 mm between adjacent holes) are opened and filled with conductive adhesive EC-1000.

[0083] 3. Shielding layer 3: The inner layer is a 0.18mm thick aluminum-plastic composite tape 31 (model AL-PET-02, polyethylene plastic layer HDPE-5000S 0.1mm, aluminum layer 0.08mm, overlap rate 25%), with conductive silver paste bonded to the aluminum layer; the middle layer is a 0.15mm diameter tin-plated copper wire (model TR-T2) braided layer 32 (braid density 90%); the outer layer is a 100g / m² conductive carbon fiber cloth 33 (model T700-12K), which is bonded to the braided layer with 0.08mm thick conductive adhesive EC-1000.

[0084] 4. Buffer layer 5: 0.6mm thick, made of halogen-free flame-retardant thermoplastic elastomer (model TPE-EF80, oxygen index 32%, Shore hardness 60A); embedded with 4 aramid fiber reinforcing ribs 4 (model Kevlar-49) with a diameter of 0.4mm, with an adjacent spacing of 12mm (aramid fiber breaking strength 2800MPa, elastic modulus 130GPa).

[0085] 5. Outer sheath 6: Thickness 1.2mm, calculated by weight, weather-resistant polyvinyl chloride material (model PVC-WH70, UVB3 grade), with added organic modified montmorillonite DK2 (layer spacing 3nm); inner surface anti-slip grooves 61 with a depth of 0.25mm and a spacing of 6mm, outer surface frosted.

[0086] Preparation process:

[0087] S1. Preparation of conductor core 1: Select TR-T2 type tin-plated soft round copper wire with a diameter of 0.2mm, and use a stranding machine to strand the wire. The stranding tension is controlled at 8N, and the stranding pitch is set at 1.6mm (8 times the diameter of each copper wire). After stranding, send the stranded wire into a re-stranding machine for re-stranding. The re-stranding tension is controlled at 12N, and the re-stranding pitch is adjusted to 12 times the diameter of the finished conductor core (for example, when the diameter of the finished conductor core is 2mm, the re-stranding pitch is 24mm). After re-stranding, the conductor core 1 is pulled by a traction wheel at a traction speed of 12m / min to ensure that the conductor core 1 has a compact structure and a smooth, burr-free surface.

[0088] S2. Insulation Layer 2 Coating and Equipotential Pretreatment: PPR-CT100 polyolefin resin, VK-SP30 nano silica, FR-PP-01 halogen-free phosphorus-nitrogen flame retardant, and 1010 antioxidant are added to a high-speed mixer at a mass ratio of 80:10:6:4. The mixing temperature is 90℃, and the mixing time is 20 minutes. After uniform mixing, the mixture is fed into the extruder hopper. The extruder temperature settings are as follows: feeding section 160℃, compression section 170℃, homogenization section 180℃, die head temperature 175℃, and extrusion speed 8m / min. Insulation layer 2 is uniformly coated on the outside of the conductor core through a cross die head. During the coating process, the die pressure is controlled at 10MPa to ensure uniform thickness of insulation layer 2. After coating, the mixture is immediately sent to a cold water cooling tank for cooling and shaping. The cooling water temperature is controlled at 25℃, and the cooling length is [not specified]. For 5m, ensure rapid curing of insulation layer 2 without bubbles or cracks; after cooling and setting, use a CNC grooving machine to process three annular conductive grooves 21 on the outer surface of the insulation layer, with a groove width of 2mm, a depth of 0.2mm, and a spacing of 50mm between adjacent grooves; then use a laser drilling machine to open conductive through holes 22, with a diameter of 0.15mm, 8 of which are evenly distributed around the circumference of insulation layer 2, with a spacing of 10mm between adjacent through holes; fill the conductive grooves 21 with AG-8830 high-temperature conductive silver paste at a filling amount of 0.05g / cm, and dry them with a hot air gun at a drying temperature of 120℃ for 5min; inject EC-1000 two-component epoxy conductive adhesive into the conductive through holes at an injection pressure of 0.3MPa to ensure that the conductive adhesive fills the through holes without gaps, and then cure at room temperature for 24h.

[0089] S3, Shielding Layer 3 Covering: The pre-treated insulated core wire is fed into the covering machine and covered with AL-PET-02 type aluminum-plastic composite tape 31. The aluminum layer faces inward and is in close contact with the conductive silver paste. The covering tension is controlled at 9N, the overlap rate is strictly controlled at 25%, and the covering speed is matched with the extrusion speed of insulation layer 2 at 8m / min. After covering, it is fed into the braiding machine to braid TR-T2 type tin-plated copper wire. The braiding density is set at 90%, the braiding tension is controlled at 5N / copper wire, and the braiding speed is 6m / min. After braiding, EC-1000 type conductive adhesive is evenly coated on the outside of the braided layer using a glue coating machine. The adhesive thickness is 0.08mm, and the glue coating speed is 5m / min. Then, T700-12K type conductive carbon fiber cloth 33 is wrapped around it with a wrapping tension of 6N and an overlap rate of 5%. After wrapping, it is compacted by a pressure roller with a compaction pressure of 2-3MPa to form a complete shielding layer 3.

[0090] S4. Filling the buffer layer 5: TPE-EF80 halogen-free flame-retardant thermoplastic elastomer is fed into the extruder. The temperature settings for each section of the extruder are: feeding section 140℃, compression section 150℃, homogenization section 160℃, and die head temperature 155℃. At the same time, Kevlar-49 aramid fiber reinforcing ribs 4 (diameter 0.4mm) are introduced into the extruder die head through the guide wire device to ensure that the four reinforcing ribs are evenly distributed along the circumference of the insulating core wire, with a spacing of 12mm between adjacent reinforcing ribs. The extrusion speed is controlled at 5m / min. The buffer layer 5 is extruded synchronously on the outside of the shielding layer 3, and the thickness of the buffer layer 5 is controlled at 0.6mm. After extrusion, it is sent to the cooling tank for cooling and shaping. The cooling water temperature is 30℃. After cooling, it is compacted and shaped by the pressure roller with a compaction pressure of 2MPa to enhance the bonding force between the buffer layer 5 and the shielding layer 3.

[0091] S5, Outer Sheath 6 Covering and Finished Product Processing: 100 parts of PVC-WH70 weather-resistant polyvinyl chloride cable material, 0.6 parts of UV-531 ultraviolet absorber, 0.6 parts of 1076 anti-aging agent, and 3 parts of DK2 organic modified montmorillonite are added to a high-speed mixer at a mixing temperature of 100℃ for 25 minutes. After uniform mixing, the mixture is fed into an extruder. The extruder temperature settings are as follows: feeding section 150℃, compression section 160℃, homogenization section 170℃, die head temperature 165℃, and extrusion speed 6m / min. The extruder is equipped with an anti-slip belt. The groove 61 mold is covered with an outer sheath 6 on the outside of the buffer layer 5. The groove parameters inside the mold match the design requirements (depth 0.25mm, spacing 6mm), and the die pressure is controlled at 9MPa. After covering, it is sent to the cooling tank for cooling. The cooling water temperature is 25℃, and the cooling length is 6m. After cooling, it is pulled by a traction machine. The traction speed is synchronized with the extrusion speed at 6m / min. Finally, it is taken up by a take-up machine. The take-up tension is controlled at 15N, and the take-up reel diameter is 1.2m. After the take-up is completed, the finished cable is inspected for appearance, size measurement and performance sampling. After passing the inspection, it is put into storage.

[0092] Example 2: Equipotential bonding method using axial conductive rib welding

[0093] A high-performance anti-interference low-voltage cable, such as Figure 1-5 As shown, it includes a conductor core 1, an insulating layer 2, a shielding layer 3, a buffer layer 5, and an outer sheath 6 arranged coaxially from the inside out. The structure and parameters are as follows:

[0094] 1. Conductor core 1: It is made of multiple strands of tin-plated copper wire (model TR-T2) with a diameter of 0.3mm through a bundle stranding and re-stranding process. The bundle stranding pitch is 10 times the diameter of each copper wire, and the re-stranding pitch is 15 times the diameter of the conductor core.

[0095] 2. Insulation layer 2: 1.2 mm thick, modified polyolefin composite material with the same proportions as in Example 1.

[0096] 3. Equipotential bonding and shielding layer 3: Six axial conductive ribs 23 (model TR-T2-Ag) with a diameter of 0.3mm silver-plated copper wire are evenly distributed on the outside of the insulation layer 2. One end is welded to the conductor core 1, and the other end is welded to the aluminum layer 31 of the aluminum-plastic composite tape. The aluminum-plastic composite tape is 0.2mm thick (model AL-PET-02, polyethylene plastic layer HDPE-5000S 0.12mm, aluminum layer 0.08mm, overlap rate 30%). Tin-plated copper wire braided layer 32 (0.18mm diameter, model TR-T2, braiding density 95%). Conductive carbon fiber cloth 33 (model T700-12K) has a surface density of 120g / m³. 2 They are bonded together using 0.1mm thick conductive adhesive EC-1000.

[0097] 4. Buffer layer 5: 0.8mm thick, halogen-free flame-retardant thermoplastic elastomer (model TPE-EF80, oxygen index 35%, Shore hardness 65A); embedded with 6 aramid fiber reinforcing ribs 4 (model Kevlar-49) with a diameter of 0.5mm, with an adjacent spacing of 15mm (tensile strength 3000MPa, elastic modulus 140GPa).

[0098] 5. Outer sheath 6: 1.5mm thick, weather-resistant polyvinyl chloride material (model PVC-WH70, UVB4 grade), with added organic modified montmorillonite DK2 (layer spacing 5nm); inner surface anti-slip grooves 61 with a depth of 0.3mm and a spacing of 8mm, outer surface frosted.

[0099] Preparation process:

[0100] S1. Preparation of conductor core 1: Select TR-T2 type tin-plated soft round copper wire with a diameter of 0.3mm, and use a stranding machine to strand the wire. The stranding tension is controlled at 10N, and the stranding pitch is set at 3mm (10 times the diameter of each copper wire). After stranding, the wire is sent to a re-stranding machine for re-stranding. The re-stranding tension is controlled at 15N, and the re-stranding pitch is adjusted to 15 times the diameter of the finished conductor core (for example, when the diameter of the finished conductor core is 3mm, the re-stranding pitch is 45mm). The traction speed after re-stranding is controlled at 8-10m / min to ensure that the conductor core 1 has a compact structure and stable conductivity.

[0101] S2, Insulation Layer 2 Coating: PPR-CT100 type polyolefin resin, VK-SP30 type nano silica, FR-PP-01 type halogen-free phosphorus nitrogen flame retardant, and 1010 type antioxidant are added to a high-speed mixer at a mass ratio of 80:10:6:4. The mixing temperature is 90℃ and the mixing time is 20min. After uniform mixing, the mixture is fed into an extruder. The temperatures of each section of the extruder are: feeding section 160℃, compression section 170℃, homogenization section 180℃, die head temperature 175℃, and extrusion speed 7m / min. Insulation layer 2 is coated on the outside of the conductor core through a cross die head. The die pressure is 10MPa to ensure that the insulation layer 2 has a uniform thickness of 1.2mm. After coating, the mixture is sent to a cold water cooling tank for cooling and shaping. The cooling water temperature is 25℃ and the cooling length is 5m. After cooling, the surface of insulation layer 2 is smooth and without defects.

[0102] S3. Equipotential bonding and shielding layer 3 covering: TR-T2-Ag type silver-plated soft round copper wire (0.3mm diameter) is cut into axial conductive ribs 23 matching the cable production length. One end of each of the six conductive ribs is welded to the conductor core 1 using a resistance welding machine. The welding current is 20A, and the welding time is 0.5s, ensuring a strong weld without any incomplete welds. The welded conductive ribs are then evenly distributed along the circumference of the insulation layer, with a spacing of 15mm between adjacent ribs, and secured with temporary clamps. Subsequently, the cable is fed into a covering machine to cover with AL-PET-02 type aluminum-plastic composite tape, with the aluminum layer facing inwards and welded to the axial conductive ribs 23. The welding current is... 16A, welding time 0.8s, aluminum-plastic composite tape thickness 0.2mm (polyethylene plastic layer HDPE-5000S 0.12mm, aluminum layer 0.08mm), overlap rate 30%, wrapping tension 10N; after wrapping, it is fed into a braiding machine to braid TR-T2 type tin-plated copper wire (diameter 0.18mm), braiding density 95%, braiding tension 6N / copper wire, braiding speed 5m / min; after braiding, it is coated with EC-1000 type conductive adhesive, coating thickness 0.1mm, coating speed 4m / min; then wrapped with T700-12K type conductive carbon fiber cloth 33 (area density 120g / m³). 2 The wrapping tension is 7N, the overlap rate is 5%, and the wrapping is compacted by the pressure roller (compaction pressure 3MPa) to form a shielding layer 3.

[0103] S4, Buffer Layer 5 Filling: TPE-EF80 halogen-free flame-retardant thermoplastic elastomer is fed into the extruder. The extruder temperatures are as follows: feeding section 140℃, compression section 150℃, homogenization section 160℃, and die head temperature 155℃. Six 0.5mm diameter Kevlar-49 aramid fiber reinforcing ribs 4 are introduced into the die head through the guide device and evenly distributed circumferentially (adjacent spacing 15mm). They are extruded synchronously with the flame-retardant elastomer onto the outside of the shielding layer 3 at an extrusion speed of 4m / min. The thickness of the buffer layer 5 is controlled at 0.8mm. After extrusion, the layer is cooled and shaped (cooling water temperature 30℃, cooling length 5m), and then compacted and shaped by pressure rollers (compaction pressure 2MPa) to ensure that the reinforcing ribs are not misaligned and the buffer layer is free of voids.

[0104] S5, Outer Sheath 6 Covering and Finished Product Processing: Calculate by weight parts, add 100 parts of PVC-WH70 weather-resistant polyvinyl chloride cable material, 0.6 parts of UV-531 ultraviolet absorber, 0.6 parts of 1076 anti-aging agent, and 5 parts of DK2 organic modified montmorillonite to a high-speed mixer. Mixing temperature: 100℃, mixing time: 25min. After uniform mixing, feed into an extruder. Extruder temperatures: feeding section 150℃, compression section 160℃, homogenization section 170℃, die head temperature 1℃. The extrusion temperature is 65℃ and the extrusion speed is 5m / min. The outer sheath 6 is covered by a die with anti-slip grooves 61. The groove depth of the die is 0.3mm and the spacing is 8mm. The die pressure is 9MPa. After covering, the product is cooled (cooling water temperature 25℃, cooling length 6m), pulled by a traction machine (traction speed 5m / min), and wound up by a take-up machine (take-up tension 18N, take-up reel diameter 1.2m). After the product is finished, the appearance, size and performance are inspected and tested (including tensile strength, shielding attenuation, waterproof rating, etc.). After passing the test, it is packaged and stored.

[0105] The above embodiments are merely preferred embodiments of the present invention. To further highlight the advantages of the inventive point of the present invention, comparative examples are provided below:

[0106] Comparative Example 1: Lack of equipotential bonding + single-layer shielding

[0107] A low-voltage cable with the following structure and parameters (only the shielding layer and equipotential bonding differ from Example 1; the rest of the structure / materials / parameters are the same as in Example 1):

[0108] Shielding layer 3: Only a single layer of tin-plated copper wire braided layer 32 (0.15mm diameter, model TR-T2, braiding density 90%) is provided, without aluminum-plastic composite tape layer 31 and conductive carbon fiber cloth 33; there is no equipotential connection structure, and the aluminum-plastic composite tape is omitted.

[0109] Preparation process: The equipotential bonding process is omitted, and tin-plated copper wires are directly braided on the outside of the insulating layer 2 to form the shielding layer 3.

[0110] Comparative Example 2: Buffer layer without aramid fiber reinforcement

[0111] A low-voltage cable has the following structure and parameters (only the buffer layer differs from Example 1; the rest of the structure / materials / parameters are the same as in Example 1):

[0112] Buffer layer 5: 0.6mm thick, made of halogen-free flame-retardant thermoplastic elastomer of model TPE-EF80 (oxygen index 32%, Shore hardness 60A), without embedded aramid fiber reinforcing ribs 4.

[0113] Preparation process: The step of laying aramid fiber reinforcing ribs 4 is omitted, and flame-retardant elastomer material is directly extruded to form a buffer layer 5.

[0114] Comparative Example 3: Outer Sheath without Nano-Montmorillonite Modification

[0115] A low-voltage cable with the following structure and parameters (only the outer sheath differs from Example 1; the rest of the structure / materials / parameters are the same as in Example 1):

[0116] Outer sheath: 1.2mm thick, made of weather-resistant PVC cable material of model PVC-WH70, with only UV-531 ultraviolet absorber and 1076 anti-aging agent added, and no nano montmorillonite filler added; the inner surface anti-slip groove and the outer surface frosted treatment are the same as in Example 1.

[0117] Preparation process: The step of adding nano-montmorillonite is omitted, and the outer sheath is directly covered with unmodified weather-resistant polyvinyl chloride material.

[0118] Performance test results

[0119] Test Project Test methods (based on standards) Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Tensile strength (kN / mm²) GB / T12706.1-2022 Tensile Test Method for Conductors and Insulated Cores of Cables 16 18 15.8 8 15.9 Bending radius (times the cable diameter) GB / T12706.1-2022 Cable Bending Test Method 6 7 6 10 6 Breakdown field strength (kV / mm) GB / T1408.1-2016 Test Method for Electrical Strength of Insulating Materials 28 30 27 28 28 Shielding attenuation (dB) GB / T12706.5-2022 Cable Shielding Attenuation Test Method (10kHz-1GHz) 98 102 65 97 98 Waterproof rating GB / T4208-2017 Test Methods for Degrees of Protection Provided by Enclosures (IP Code) IP67 IP68 IP67 IP67 IP65 Temperature range (°C) GB / T29510-2013 General Test Methods for Insulation and Sheath Materials of Cables and Optical Fibers: Thermal Aging Test -40~105 -40~110 -40~105 -40~105 -40~105 Flame retardant rating UL 94-2021 Test Method for Flammability of Plastic Materials V-0 V-0 V-0 V-0 V-0 Bending fatigue performance (after 1000 cycles) GB / T12706.1-2022 Cable Repeated Bending Test Method No interlayer delamination, structural integrity No interlayer delamination, structural integrity No interlayer delamination, structural integrity interlayer delamination occurs No interlayer delamination, structural integrity Wear resistance (wear amount after 500 hours) GB / T29510-2013 Test Method for Abrasion Resistance of Cable Sheath 0.12mm 0.10mm 0.13mm 0.12mm 0.30mm (2.5 times that of Example 1) UV aging performance (after 1000h) GB / T16422.2-2014 Plastics Laboratory Light Source Exposure Test Methods Part 2: Xenon Arc Lamps No cracks, no aging or discoloration No cracks, no aging or discoloration No cracks, no aging or discoloration No cracks, no aging or discoloration Cracking occurred

[0120] Note: The test methods in the table all adopt current national standards or industry-standards. The test results are the average of three parallel tests to ensure data accuracy. The data in the table clearly shows that Embodiments 1 and 2 of this invention are superior to their counterparts in key performance aspects such as shielding attenuation, tensile strength, waterproof rating, wear resistance, and aging resistance, highlighting the synergistic advantages of each innovative aspect.

[0121] The shielding attenuation of Examples 1 and 2 reached 98dB and 102dB respectively, far exceeding the 65dB of Comparative Example 1. This difference stems from the three-layer composite shielding + equipotential bonding of the present invention. Comparative Example 1 only uses a single layer of tin-plated copper wire braided shielding, which cannot achieve full-band electromagnetic signal interception, especially with weak reflection and absorption capabilities for low-frequency signals. In contrast, the Examples 1 and 2 form a shielding system covering the entire frequency band from 10kHz to 1GHz through the synergistic effect of AL-PET-02 aluminum-plastic composite tape (low-frequency shielding), TR-T2 tin-plated copper wire braided layer (high-frequency shielding), and T700-12K conductive carbon fiber cloth (high-frequency reinforcement). At the same time, the equipotential bonding structure (conductive silver paste + through holes in Example 1, axial conductive ribs in Example 2) eliminates the potential difference between the shielding layer and the conductor core, avoiding interference from parasitic electric fields on the shielding effect, further improving the shielding attenuation of Example 2 to 102dB, meeting the usage requirements of strong electromagnetic interference environments (such as industrial automated workshops and the vicinity of new energy equipment).

[0122] Tensile strength: Example 1 (16kN / mm) 2 Example 2 (18kN / mm) 2 Comparative Example 2 (8kN / mm) 2 The tensile strength is more than doubled. The key reason lies in the design of the double-stranded conductor core and aramid-reinforced buffer layer of this invention: the double stranding makes the TR-T2 tin-plated copper wires more tightly arranged and the tension more uniform, improving the tensile strength of the conductor core; while the Kevlar-49 aramid fiber reinforcement (fracture strength ≥2800MPa) embedded in the buffer layer forms an axial skeleton support, which can effectively disperse the tensile force. Example 2, due to the use of thicker conductor core copper wire (0.3mm) and more aramid reinforcement (6 strands), further improves the tensile strength. Comparative Example 2, due to the lack of aramid reinforcement, relies solely on the strength of the TPE-EF80 elastomer, which cannot withstand large tensile forces, resulting in a significant deterioration in tensile performance.

[0123] Bending performance: The bending radii of Examples 1 and 2 are only 6-7 times the cable diameter, far less than 10 times that of Comparative Example 2; and after 1000 bending fatigue tests, none of the Examples showed interlaminar delamination, while Comparative Example 2 showed obvious delamination. This is because the rigid support of the aramid reinforcement and the flexible buffer of the elastomer work synergistically to disperse stress during bending and avoid localized stress concentration; at the same time, the anti-slip grooves of the outer sheath enhance the bonding force with the buffer layer, further improving structural stability. Comparative Example 2, lacking reinforcement, experiences stress concentration at the interlaminar interface during bending, inevitably leading to delamination after long-term fatigue.

[0124] Wear resistance and aging resistance: Examples 1 and 2 showed wear resistance of only 0.12 mm and 0.10 mm after 500 hours, respectively, and no cracking occurred after 1000 hours of UV aging. In contrast, Comparative Example 3 showed a wear resistance of 0.30 mm (2.5 times that of Example 1) and exhibited aging cracking. The core reason is the addition of DK2 organically modified montmorillonite to the outer sheath of this invention. Its layered structure forms a nano-reinforcing network, which not only blocks the erosion of abrasive media but also improves the material's hardness. Combined with the synergistic effect of UV-531 ultraviolet absorber and 1076 anti-aging agent, it delays material aging. Comparative Example 3, lacking nano-montmorillonite, had insufficient structural density in its outer sheath, resulting in a significant decrease in wear resistance and aging resistance.

[0125] The above embodiments are provided for those skilled in the art to implement or use the present invention. Those skilled in the art can make various modifications or changes to the above embodiments without departing from the inventive concept of the present invention. Therefore, the protection scope of the present invention is not limited to the above embodiments, but should be the maximum scope that conforms to the innovative features mentioned in the claims.

Claims

1. A high-performance anti-interference low-voltage cable, characterized in that, It includes a conductor core (1), an insulation layer (2), a shielding layer (3), a buffer layer (5), and an outer sheath (6) arranged coaxially from the inside to the outside. The conductor core (1) is made of multiple strands of tin-plated copper wire through a double stranding process of bundle stranding and re-stranding; The insulating layer (2) covers the outside of the conductor core (1) and has a thickness of 0.8-1.2 mm. It is made of modified polyolefin composite material. The modified polyolefin composite material is made by mixing polyolefin resin, nano silica, flame retardant and antioxidant in a mass ratio of 80:10:6:

4. The shielding layer (3) is a double-layer structure, including an inner aluminum-plastic composite strip (31) and an outer tin-plated copper wire braided layer (32). The thickness of the aluminum-plastic composite strip (31) is 0.15-0.2mm, the overlap rate is not less than 25%, and the aluminum layer of the aluminum-plastic composite strip (31) faces inward and forms an equipotential connection with the conductor core (1). The braiding density of the tin-plated copper wire braided layer (32) is not less than 90%, the diameter of the tin-plated copper wire is 0.12-0.18mm, and a layer of conductive carbon fiber cloth (33) is wrapped around the outside of the braided layer. The buffer layer (5) is filled between the shielding layer (3) and the outer sheath (6), with a thickness of 0.5-0.8 mm, and is made of flame-retardant elastomer material; the oxygen index of the flame-retardant elastomer material is not less than 32%, and the Shore hardness is 55-65A; The buffer layer (5) is uniformly embedded with several aramid fiber reinforcing ribs (4) along the cable axis. The diameter of the aramid fiber reinforcing ribs (4) is 0.3-0.5 mm, and the spacing between adjacent aramid fiber reinforcing ribs (4) is 10-15 mm. The outer sheath (6) has a thickness of 1.0-1.5 mm. According to the weight, it is made of weather-resistant polyvinyl chloride material with 0.3-0.8 parts of ultraviolet absorber and 0.2-0.6 parts of anti-aging agent added, wherein the weather-resistant polyvinyl chloride material is 100 parts, and the inner surface of the outer sheath (6) is provided with anti-slip groove (61). The outer sheath (6) also contains uniformly dispersed nano-montmorillonite filler, the amount of which is 3-5% of the mass of the weather-resistant polyvinyl chloride material.

2. The high-performance anti-interference low-voltage cable according to claim 1, characterized in that, The diameter of each tinned copper wire is 0.1-0.3mm, the stranding pitch is 8-10 times the diameter of each copper wire, and the double stranding pitch is 12-15 times the diameter of the conductor core.

3. The high-performance anti-interference low-voltage cable according to claim 1, characterized in that, The anti-slip groove (61) has a depth of 0.2-0.3 mm and a spacing of 5-8 mm.

4. The high-performance anti-interference low-voltage cable according to claim 1, characterized in that, The conductive carbon fiber cloth (33) and the tin-plated copper wire braided layer (32) are bonded and fixed together by conductive adhesive, the thickness of which is 0.05-0.1mm.

5. The high-performance anti-interference low-voltage cable according to claim 1, characterized in that, The nano-montmorillonite filler is organically modified montmorillonite with an interlayer spacing of 2-5 nm.

6. The high-performance anti-interference low-voltage cable according to claim 1, characterized in that, The plastic layer of the aluminum-plastic composite strip (31) is made of polyethylene material with a thickness of 0.08-0.12 mm, and the aluminum layer has a thickness of 0.07-0.08 mm.

7. The high-performance anti-interference low-voltage cable according to claim 1, characterized in that, The equipotential connection between the aluminum layer of the aluminum-plastic composite tape (31) and the conductor core (1) is achieved through the following structure: 3-5 annular conductive grooves (21) are uniformly opened along the circumference on the outer surface of the insulating layer (2). The conductive grooves (21) are filled with conductive silver paste. The aluminum layer of the aluminum-plastic composite tape (31) is attached to the conductive silver paste and is in close contact with the conductive silver paste. The conductive silver paste is connected to the conductor core (1) through the pre-set conductive through hole (22) on the insulating layer to form a stable equipotential path.

8. The high-performance anti-interference low-voltage cable according to claim 7, characterized in that, The diameter of the conductive via (22) is 0.1-0.2 mm, and it is evenly distributed along the circumference of the insulating layer. The spacing between adjacent conductive vias (22) is 8-12 mm. The conductive vias (22) are filled with conductive adhesive to achieve reliable conduction between the conductive silver paste and the conductor core.

9. The high-performance anti-interference low-voltage cable according to claim 1, characterized in that, The equipotential connection between the aluminum layer of the aluminum-plastic composite tape (31) and the conductor core (1) is achieved through axial conductive ribs (23): the axial conductive ribs (23) are arranged along the length of the cable, and there are 4-6 ribs, which are evenly distributed between the insulation layer (2) and the aluminum-plastic composite tape (31). One end of the axial conductive rib (23) is welded and fixed to the conductor core (1), and the other end is welded and fixed to the aluminum layer of the aluminum-plastic composite tape (31). The diameter of the axial conductive rib (23) is 0.2-0.3mm, and it is made of silver-plated copper wire.

10. A manufacturing process for a high-performance anti-interference low-voltage cable as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Conductor core (1) Preparation: Select tin-plated copper wire with a diameter of 0.1-0.3mm, first bundle it through a bundling machine, and control the bundling pitch at 8-10 times the diameter of each copper wire. Then re-twist it through a re-twist machine, and control the re-twist pitch at 12-15 times the diameter of the conductor core to make the conductor core. S2, Insulation layer (2) Coating: The modified polyolefin composite material is put into the extruder, the extrusion temperature is controlled at 160-180℃, the extrusion speed is 5-8m / min, and the insulation layer is uniformly coated on the outside of the conductor core. After coating, it is cooled and shaped by cold water. S3, Shielding layer (3) covering: If an equipotential connection structure of annular conductive groove (21) + conductive silver paste is adopted, first process annular conductive groove (21) on the outside of the insulation layer and fill it with conductive silver paste and conduct conductive through hole (22); if an equipotential connection structure of axial conductive rib (23) is adopted, first weld and fix the axial conductive rib (23) to the conductor core (1) and lay it along the circumference of the insulation layer (2); then wrap aluminum-plastic composite tape (31) on the outside of the insulation layer (2), ensuring that the overlap rate is not less than 25% and the aluminum layer faces inward and is in close contact with conductive silver paste or axial conductive rib (23), then braid tin-plated copper wire by braiding machine, control the braiding density to be not less than 90%, then coat the outside of the braided layer with conductive adhesive and wrap conductive carbon fiber cloth (33), and compact it to form a complete shielding layer (3); S4, Buffer layer (5) filling: Flame retardant elastomer material and aramid fiber reinforcing rib (4) are extruded onto the outside of the shielding layer through an extruder. The thickness of the buffer layer is controlled to be 0.5-0.8mm to ensure that the aramid fiber reinforcing rib (4) is evenly distributed and without deviation. After filling, it is compacted and shaped. S5, Outer sheath (6) covering: Weather-resistant polyvinyl chloride material is put into an extruder, the extrusion temperature is 150-170℃, the extrusion speed is 4-6m / min, and the outer sheath (6) is covered on the outside of the buffer layer (5). During the covering process, the anti-slip groove (61) is pressed out by the mold. Finally, after cooling, pulling and winding, the finished cable is made.

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