Three-layer co-extrusion cable

Abstract

The utility model relates to the technical field of power cables, and provides a three-layer co-extrusion cable, which comprises a conductor, a conductor shielding layer, an insulating layer, an insulating shielding layer, a metal shielding tape, an armor layer and a sheath layer, the conductor shielding layer, the insulation layer and the insulation shielding layer are integrally formed, the conductor shielding layer, the insulation layer and the insulation shielding layer are sequentially arranged outside the conductor in a wrapping mode, the metal shielding belt is arranged outside the insulation shielding layer in a wrapping mode, the armor layer is arranged outside the metal shielding belt in a wrapping mode, and the sheath layer is arranged outside the armor layer in a wrapping mode. According to the three-layer co-extrusion cable provided by the utility model, the conductor shielding layer, the insulating layer and the insulation shielding layer are integrally formed and are sequentially and tightly coated outside the conductor, so that the overall stability and the mechanical strength of the cable are enhanced. The tight combination mode reduces the gaps between the layers, and effectively prevents the problems of conductor extension and insulation shrinkage, thereby improving the reliability and durability of the cable.

Description

Technical Field

[0001] The utility model relates to the technical field of power cables, in particular to a three-layer co-extruded cable. Background Art

[0002] In the field of medium-voltage power cables, especially where aluminum alloy wire conductors are used as cable conductors, a common industry problem exists. Aluminum alloy wire conductors are widely used in medium-voltage power cables for new energy projects such as onshore wind power and photovoltaics due to their excellent conductivity and lightweight properties. However, the surface of this conductor is smooth, and during the three-layer co-extrusion process of medium-voltage power cables, the friction between the conductor surface and the inner shielding layer (i.e., the conductor shielding layer) is relatively small. Especially in the case of small-section wire conductors, compared with large-section wire conductors, the contact area between them and the inner shielding layer is smaller, the friction stress along the axial direction is correspondingly reduced, and the resistance to insulation shrinkage is weakened.

[0003] This characteristic leads to a significant problem: after the cross-linking process is completed for the small-section aluminum alloy wire conductors of medium-voltage power cables, conductor extension and insulation shrinkage often occur. Even if the protruding portion is sawed off during the installation of cable joints and terminals, the problem may still persist because the conductor extension and insulation shrinkage may continue to occur during the long-term operation of the cable. Over time, the gap between the cable insulation and the stress cone insulation of the accessories gradually increases. This can easily lead to breakdown of the cable accessories under high voltage field strength, posing a serious threat to the safe operation of the entire medium-voltage cable system. Utility Model Content

[0004] The utility model provides a three-layer co-extruded cable, which is used to solve the problem that the gap between the cable body insulation and the accessory stress cone insulation gradually increases, which easily leads to the breakdown of the cable accessories under high voltage field strength.

[0005] The utility model provides a three-layer co-extruded cable, comprising: a conductor, a conductor shielding layer, an insulating layer, an insulating shielding layer, a metal shielding tape, an armor layer and a sheath layer;

[0006] The conductor shielding layer, the insulating layer and the insulating shielding layer are integrally formed, and the conductor shielding layer, the insulating layer and the insulating shielding layer are sequentially wrapped around the conductor, the metal shielding tape is wrapped around the insulating shielding layer, the armor layer is wrapped around the metal shielding tape, and the sheath layer is wrapped around the armor layer.

[0007] According to a three-layer co-extruded cable provided by the utility model, the conductor shielding layer is a semi-conductive polyethylene layer, the insulating layer is a cross-linked polyethylene layer, and the insulating shielding layer is an insulating polyethylene layer;

[0008] The semiconductive polyethylene layer, the cross-linked polyethylene layer and the insulating polyethylene layer are integrally formed, the semiconductive polyethylene layer is arranged on the inner layer of the cross-linked polyethylene layer, and the insulating polyethylene layer is arranged on the outer layer of the cross-linked polyethylene layer.

[0009] According to the three-layer co-extruded cable provided by the present invention, the conductor is an aluminum alloy conductor.

[0010] According to a three-layer co-extruded cable provided by the utility model, the aluminum alloy conductor has a multi-strand twisted structure, and the surface of each strand of the twisted structure is uniformly coated with an anti-oxidation layer.

[0011] According to a three-layer co-extruded cable provided by the utility model, the thickness of the semi-conductive polyethylene layer is between 0.1 mm and 0.5 mm, the thickness of the cross-linked polyethylene layer is between 1 mm and 5 mm, and the thickness of the insulating polyethylene layer is between 0.1 mm and 0.5 mm.

[0012] According to a three-layer co-extruded cable provided by the utility model, the outer surface of the insulating polyethylene layer is formed with a raised texture, and the metal shielding tape is suitable for being bonded to the outside of the insulating polyethylene layer through the raised texture.

[0013] According to a three-layer co-extruded cable provided by the utility model, the metal shielding tape is wrapped around the insulating shielding layer in an overlapping or spirally wound manner.

[0014] According to a three-layer co-extruded cable provided by the present invention, the armor layer includes at least one layer of a mesh structure woven from high-strength steel wires or aramid fibers, and the mesh structure is tightly attached to the outside of the metal shielding tape.

[0015] According to a three-layer co-extruded cable provided by the utility model, the sheath layer comprises: an inner sheath layer and an outer sheath layer;

[0016] The inner sheath layer and the outer sheath layer are coated on the outside of the armor layer. An identification strip is embedded in the outer sheath layer. The identification strip is printed with at least one of the specifications, model, production date and manufacturer of the cable.

[0017] According to a three-layer co-extruded cable provided by the utility model, the three-layer co-extruded cable further includes: a fire-retardant layer, which is arranged between the armor layer and the inner sheath layer, and / or between the inner sheath layer and the outer sheath layer.

[0018] The three-layer co-extruded cable provided by the present invention enhances the overall stability and mechanical strength of the cable by integrally forming the conductor shielding layer, the insulation layer and the insulation shielding layer and tightly wrapping them around the conductor in sequence. This tight combination reduces the gaps between the layers, effectively preventing the problems of conductor extension and insulation shrinkage, thereby improving the reliability and durability of the cable. The presence of the conductor shielding layer and the insulation shielding layer not only provides additional electrical protection for the cable, but also optimizes the electric field distribution of the cable. It helps to reduce electric field distortion, reduce the risk of cable breakdown under high voltage field strength, and ensure the safe operation of the cable. The provision of the metal shielding tape enhances the cable's ability to resist electromagnetic interference, can effectively shield the interference of external electromagnetic fields, and protect the electrical signals inside the cable from being affected, thereby ensuring the stable operation of the cable in complex electromagnetic environments. The covering of the armor layer and the sheath layer provides additional physical protection and security for the cable. The armor layer can withstand external mechanical impact and extrusion, while the sheath layer has excellent weather resistance and corrosion resistance, and can protect the cable from environmental factors for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is one of the schematic diagrams of a three-layer co-extruded cable provided in an embodiment of the present utility model.

[0021] Figure 2 This is the second schematic diagram of the three-layer co-extruded cable provided in the embodiment of the present utility model.

[0022] Reference numerals:

[0023] 10. Conductor; 20. Conductor shielding layer; 30. Insulation layer; 40. Insulation shielding layer; 410. Raised texture; 50. Metal shielding tape; 60. Armor layer; 70. Sheath layer; 710. Inner sheath layer; 720. Outer sheath layer; 730. Identification strip. DETAILED DESCRIPTION

[0024] To make the purpose, technical solutions, and advantages of the present invention more clear, the following will be combined with the accompanying drawings to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] The following combination Figure 1 and Figure 2 The utility model describes a three-layer co-extruded cable.

[0026] In some embodiments, as Figure 1 and Figure 2 As shown, the three-layer co-extruded cable includes a conductor 10, a conductor shielding layer 20, an insulating layer 30, an insulating shielding layer 40, a metal shielding tape 50, an armor layer 60 and a sheath layer 70; the conductor shielding layer 20, the insulating layer 30 and the insulating shielding layer 40 are integrally formed, and the conductor shielding layer 20, the insulating layer 30 and the insulating shielding layer 40 are sequentially wrapped around the conductor 10, the metal shielding tape 50 is wrapped around the insulating shielding layer 40, the armor layer 60 is wrapped around the metal shielding tape 50, and the sheath layer 70 is wrapped around the armor layer 60.

[0027] In this embodiment, the conductor 10 serves as the core of the cable, responsible for transmitting current. The conductor shielding layer 20, located externally to the conductor 10, primarily optimizes the electric field distribution and reduces electric field distortion. The insulating layer 30, located between the conductor shielding layer 20 and the insulating shielding layer 40, provides electrical insulation. The insulating shielding layer 40, located externally to the insulating layer 30, works together with the conductor shielding layer 20 to further optimize the electric field distribution. Its surface is smooth and free of obvious defects, ensuring the cable's electrical performance. Through three-layer co-extrusion technology, the insulating layer 30 is tightly bonded to the conductor shielding layer 20 and the insulating shielding layer 40, enhancing the cable's overall stability. The metal shielding tape 50, located externally to the insulating shielding layer 40, enhances the cable's electromagnetic interference resistance. It effectively shields against external electromagnetic interference, protecting the electrical signals within the cable. The armor layer 60, located externally to the metal shielding tape 50, provides additional physical protection. It resists external mechanical shock and compression, ensuring stable operation of the cable in complex environments. The sheathing layer 70, located externally to the armoring layer 60, offers excellent weather and corrosion resistance. Long-term protection of cables from environmental factors, extending the service life of the cables.

[0028] The conductor shield layer 20, insulation layer 30, and insulation shield layer 40 are co-extruded using three-layer CCV (Continuous Cross-head Extrusion) technology. The three layers are extruded simultaneously during the extrusion process, ensuring a tight bond and uniformity between the layers. Production is performed on a CCV dry cross-linking line, specifically designed for cross-linking processes under high temperatures and pressures.

[0029] During processing, conductor 10 is preheated above the die head using induction heating technology to a temperature of 80-100°C. This preheating effectively removes moisture from conductor 10, bringing its temperature closer to the extrusion temperature. Through three-layer coextrusion, the plastic extruded onto the surface of conductor 10 achieves optimal fluidity. The interface between conductor shielding layer 20 and insulation layer 30 is smooth, free of visible stranded wire ridges, sharp corners, particles, burn marks, or scratches. The surface of insulation shielding layer 40 and its interface with insulation layer 30 are also smooth and defect-free.

[0030] To ensure processing quality, a Sikora deflectometer is used. This instrument, placed inline behind the crosshead within the separation box, utilizes X-ray scanning technology to continuously measure extrusion dimensions in real time. This measurement information is rapidly fed back to the computer control system, which calculates the thickness of the conductor shield 20, insulation layer 30, and insulation shield 40, as well as the concentricity and outer diameter of the conductor 10. This precise quality control method further ensures the roundness and concentricity of the cable. It significantly reduces insulation eccentricity caused by uneven insulation core thickness during extrusion, meeting the stringent dimensional requirements of medium-voltage cables.

[0031] The three-layer co-extruded cable provided by the present invention enhances the overall stability and mechanical strength of the cable by integrally forming the conductor shielding layer 20, the insulating layer 30 and the insulating shielding layer 40 and tightly wrapping them around the conductor 10 in sequence. This tight combination reduces the gaps between the layers, effectively preventing the problems of the conductor 10 extending and the insulation shrinking, thereby improving the reliability and durability of the cable. The presence of the conductor shielding layer 20 and the insulating shielding layer 40 not only provides additional electrical protection for the cable, but also optimizes the electric field distribution of the cable. It helps to reduce electric field distortion, reduce the risk of cable breakdown under high voltage field strength, and ensure the safe operation of the cable. The provision of the metal shielding tape 50 enhances the cable's ability to resist electromagnetic interference, can effectively shield interference from external electromagnetic fields, and protect the electrical signals inside the cable from being affected, thereby ensuring the stable operation of the cable in complex electromagnetic environments. The covering of the armor layer 60 and the sheath layer 70 provides additional physical protection and security for the cable. The armor layer 60 is capable of resisting external mechanical impact and extrusion, while the sheath layer 70 has excellent weather resistance and corrosion resistance, and can protect the cable from environmental factors for a long time.

[0032] It should be noted that a low-shrinkage inner shielding material can be used instead of a conventional inner shielding material to increase the frictional stress between the conductor 10 and the conductor shielding layer 20. The conductor shielding layer 20 is harder and less fluid than conventional materials, which increases the frictional stress between the conductor shielding layer 20, the conductor 10, and the insulating layer 30, forming adhesion forces between them.

[0033] In some embodiments, as Figure 1 and Figure 2 As shown, the conductor shielding layer 20 is a semi-conductive polyethylene layer, the insulating layer 30 is a cross-linked polyethylene layer, and the insulating shielding layer 40 is an insulating polyethylene layer; the semi-conductive polyethylene layer, the cross-linked polyethylene layer and the insulating polyethylene layer are integrally formed, the semi-conductive polyethylene layer is arranged on the inner layer of the cross-linked polyethylene layer, and the insulating polyethylene layer is arranged on the outer layer of the cross-linked polyethylene layer.

[0034] In this embodiment, the semi-conductive polyethylene has good electrical conductivity and can form a smooth transition area between the conductor 10 and the insulating layer 30, thereby optimizing the electric field distribution and reducing electric field distortion. At the same time, it can also prevent the conductor 10 from stretching out and the insulation from shrinking, thereby enhancing the overall stability and mechanical strength of the cable. Cross-linked polyethylene has excellent electrical properties and mechanical strength and can withstand high voltages and mechanical stresses. Through cross-linking treatment, the chain structure of the polyethylene molecules is converted into a mesh structure, thereby improving the material's heat resistance, chemical corrosion resistance, and wear resistance. Although the insulating polyethylene has low electrical conductivity, it has good insulating properties and physical and mechanical properties. It is arranged on the outer layer of the cross-linked polyethylene layer, further enhancing the insulation performance and protective effect of the cable. The semi-conductive polyethylene layer, the cross-linked polyethylene layer, and the insulating polyethylene layer are integrally formed through three-layer co-extrusion technology. This ensures the close bonding and uniformity between the layers, thereby improving the overall performance and reliability of the cable.

[0035] At the same time, if Figure 1 and Figure 2 As shown, conductor 10 is an aluminum alloy conductor. Aluminum alloy has a much lower density than copper, which makes cables using aluminum alloy conductors significantly lighter. Lightweight cables are more convenient to install, transport, and maintain, reducing labor intensity and costs. Aluminum alloy conductors are highly compatible with the three-layer co-extrusion structure (semi-conductive polyethylene layer, cross-linked polyethylene layer, insulating polyethylene layer). This structure, combined with the aluminum alloy conductor, prevents gap growth during use.

[0036] In some embodiments, as Figure 1 and Figure 2 As shown, the aluminum alloy conductor has a multi-strand twisted structure, and the surface of each strand is uniformly coated with an anti-oxidation layer.

[0037] Specifically, the multi-strand twisted structure allows the conductor 10 to more easily adapt to shape changes when bent, reducing stress concentration caused by bending. This helps to improve the flexibility and fatigue resistance of the cable, making it more suitable for use in complex environments.

[0038] The multi-strand twisted structure allows the conductor 10 to better disperse stress when subjected to external forces, thereby improving the cable's mechanical strength and tensile strength. The anti-oxidation layer isolates the aluminum alloy conductor from direct contact with air and moisture, thereby preventing oxidative corrosion of the conductor 10. This helps maintain the conductor's 10's excellent conductivity and appearance, extending the cable's service life. The anti-oxidation layer typically exhibits excellent weather resistance, protecting against the effects of harsh environmental factors such as ultraviolet rays, high temperatures, and humidity. This allows the cable to maintain stable electrical performance and mechanical strength when used outdoors, in humid, or highly corrosive environments.

[0039] Optionally, the thickness of the semiconductive polyethylene layer is between 0.1 mm and 0.5 mm, the thickness of the cross-linked polyethylene layer is between 1 mm and 5 mm, and the thickness of the insulating polyethylene layer is between 0.1 mm and 0.5 mm.

[0040] The semiconductive polyethylene layer primarily smoothes the electric field distribution and prevents conductor 10 extension and insulation shrinkage. Its close contact with the conductor 10 creates a transition zone, helping to reduce electric field distortion and partial discharge. The actual thickness of the semiconductive polyethylene layer is determined by the cable's rated voltage, conductor 10 dimensions, and operating environment. A thinner semiconductive polyethylene layer reduces material cost but may reduce the smoothness of the electric field distribution. A thicker layer provides better electric field control and mechanical protection, but may increase the overall cable diameter and cost.

[0041] The cross-linked polyethylene layer provides the primary electrical insulation and mechanical strength. Through the cross-linking process, the polyethylene molecular chains are transformed into a network structure, thereby improving the material's heat resistance, chemical corrosion resistance, and wear resistance.

[0042] The insulating polyethylene layer primarily protects the cross-linked polyethylene layer from environmental damage, while also helping to smooth the electric field distribution and reduce partial discharge. Similar to the semi-conductive polyethylene layer, the actual thickness of the insulating polyethylene layer is determined by the cable's rated voltage, conductor size, and operating environment. A thinner layer can reduce cable diameter and cost, but may reduce protection and smoother electric field distribution. A thicker layer provides greater protection and electric field control, but increases the overall cable diameter and cost.

[0043] In some embodiments, as Figure 2As shown, the outer surface of the insulating polyethylene layer is formed with raised textures 410 , and the metal shielding tape 50 is suitable for being bonded to the outside of the insulating polyethylene layer through the raised textures 410 .

[0044] In this embodiment, the raised texture 410 increases the contact area between the insulating polyethylene layer and the metal shielding tape 50, providing more bonding points and helping to strengthen the bond between them, preventing delamination or detachment caused by mechanical stress or environmental factors during use. Furthermore, by increasing bond strength, the raised texture 410 helps improve the mechanical stability of the cable. This allows the cable to better maintain its structural integrity when subjected to external forces, reducing the risk of performance degradation or failure due to mechanical damage.

[0045] Optional, such as Figure 2 As shown, the metal shielding tape 50 is wrapped around the insulating shielding layer 40 in an overlapping or spirally wound manner.

[0046] Overlap wrapping involves wrapping the metal shielding tape 50 tightly around the insulating shielding layer 40 with a certain overlap ratio (typically 50% or more). This ensures close contact between the metal shielding tape 50 and the insulating shielding layer 40, providing good electromagnetic shielding and mechanical protection.

[0047] Spiral winding involves wrapping the metal shielding tape 50 around the insulating shielding layer 40 at a specific pitch and angle. This method creates a continuous metal layer, providing excellent electromagnetic shielding and mechanical protection. Spiral winding offers excellent flexibility and adaptability, adapting to cable bending and stretching. It can also reduce cable diameter and weight to a certain extent, improving cable installation efficiency.

[0048] Based on the above embodiments, in some embodiments, such as Figure 1 and Figure 2 As shown, the armor layer 60 includes at least one layer of a mesh structure woven from high-strength steel wires or aramid fibers, and the mesh structure is tightly attached to the outside of the metal shielding tape 50 .

[0049] High-strength steel wire has high tensile strength and yield strength, capable of withstanding significant mechanical stress. It also exhibits excellent wear and corrosion resistance, protecting it from external physical and chemical damage. Aramid fiber is a high-performance synthetic fiber with high strength, high modulus, low density, and excellent wear resistance. It also exhibits excellent thermal and chemical stability, maintaining stable performance in extreme environments.

[0050] The mesh structure fits tightly against the metal shielding tape 50, ensuring a tight connection between the armor layer 60 and the cable's internal structure. This helps reduce the cable's diameter and weight while improving its mechanical stability and electrical performance. High-strength steel wire or aramid fiber is woven into the mesh structure through a braiding process, ensuring uniformity and consistency in the armor layer 60. This braiding process also improves the armor layer's flexibility and adaptability, allowing it to better adapt to bending and stretching deformations of the cable.

[0051] Based on the above embodiments, in some embodiments, such as Figure 2 As shown, the sheath layer 70 includes: an inner sheath layer 710 and an outer sheath layer 720; the inner sheath layer 710 and the outer sheath layer 720 are covered on the outside of the armor layer 60, and an identification strip 730 is also embedded in the outer sheath layer 720, and the identification strip 730 is printed with at least one of the cable specifications, production date, and manufacturer.

[0052] In this embodiment, the inner sheath layer 710 is in direct contact with the armor layer 60, primarily protecting the armor layer 60 from external environmental influences while also providing a certain degree of mechanical strength. The outer sheath layer 720, located further outward, not only provides further protection but also embeds an identification strip 730.

[0053] The identification strip 730 is an important information carrier, on which key information about the cable is printed, including but not limited to the cable's specifications, model, production date, and manufacturer. This information is crucial for the installation, use, and maintenance of the cable. For example, the specifications can help users quickly identify the electrical and mechanical properties of the cable to ensure its suitability for specific applications; the production date and manufacturer help track the source and quality of the cable, facilitating quality control or recall when necessary. The design of embedding the identification strip 730 in the outer sheath layer 720 ensures that the information is clearly visible and avoids damage or information ambiguity that may be caused by the external placement of the identification strip 730. This design ensures that the key information of the cable can be properly protected during transportation, storage, and use, making it easy for relevant personnel to check at any time.

[0054] like Figure 2 As shown, the three-layer co-extruded cable also includes a fire-retardant layer, which is disposed between the armor layer 60 and the inner jacket layer 710, and / or between the inner jacket layer 710 and the outer jacket layer 720. The fire-retardant layer's primary function is to prevent or slow the spread of flames along the cable, minimizing damage caused by fire. It also maintains structural strength at high temperatures, preventing the cable from breaking or short-circuiting due to combustion. Positioned between the armor layer 60 and / or the inner jacket layer 710 and the outer jacket layer 720, the fire-retardant layer protects these layers from direct damage from flames and high temperatures.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A three-layer co-extruded cable, characterized in that: include: Conductor (10), conductor shielding layer (20), insulation layer (30), insulation shielding layer (40), metal shielding tape (50), armor layer (60) and sheath layer (70); The conductor shielding layer (20), the insulating layer (30) and the insulating shielding layer (40) are integrally formed; the conductor shielding layer (20), the insulating layer (30) and the insulating shielding layer (40) are sequentially wrapped around the outside of the conductor (10); the metal shielding tape (50) is wrapped around the outside of the insulating shielding layer (40); the armor layer (60) is wrapped around the outside of the metal shielding tape (50); and the sheath layer (70) is wrapped around the outside of the armor layer (60).

2. The three-layer co-extruded cable according to claim 1, characterized in that: The conductor shielding layer (20) is a semi-conductive polyethylene layer, the insulating layer (30) is a cross-linked polyethylene layer, and the insulating shielding layer (40) is an insulating polyethylene layer; The semiconductive polyethylene layer, the cross-linked polyethylene layer and the insulating polyethylene layer are integrally formed, the semiconductive polyethylene layer is arranged on the inner layer of the cross-linked polyethylene layer, and the insulating polyethylene layer is arranged on the outer layer of the cross-linked polyethylene layer.

3. The three-layer co-extruded cable according to claim 2, characterized in that: The conductor (10) is an aluminum alloy conductor.

4. The three-layer co-extruded cable according to claim 3, characterized in that: The aluminum alloy conductor has a multi-strand twisted structure, and the surface of each strand of the twisted structure is uniformly coated with an anti-oxidation layer.

5. The three-layer co-extruded cable according to claim 2, characterized in that: The thickness of the semiconductive polyethylene layer is between 0.1 mm and 0.5 mm, the thickness of the cross-linked polyethylene layer is between 1 mm and 5 mm, and the thickness of the insulating polyethylene layer is between 0.1 mm and 0.5 mm.

6. The three-layer co-extruded cable according to claim 2, characterized in that: A raised texture (410) is formed on the outer surface of the insulating polyethylene layer, and the metal shielding tape (50) is suitable for being bonded to the outside of the insulating polyethylene layer through the raised texture (410).

7. The three-layer co-extruded cable according to claim 2, characterized in that: The metal shielding tape (50) is wrapped around the insulating shielding layer (40) in an overlapping or spirally wound manner.

8. The three-layer co-extruded cable according to any one of claims 1 to 7, characterized in that: The armor layer (60) comprises at least one layer of a mesh structure woven from high-strength steel wires or aramid fibers, and the mesh structure is tightly attached to the outside of the metal shielding tape (50).

9. The three-layer co-extruded cable according to any one of claims 1 to 7, characterized in that: The sheath layer (70) comprises: an inner sheath layer (710) and an outer sheath layer (720); The inner sheath layer (710) and the outer sheath layer (720) are coated outside the armor layer (60); an identification strip (730) is also embedded in the outer sheath layer (720); and at least one of the specifications, model, production date, and manufacturer of the cable is printed on the identification strip (730).

10. The three-layer co-extruded cable according to claim 9, characterized in that: The three-layer co-extruded cable further comprises: a fire-retardant layer, wherein the fire-retardant layer is arranged between the armor layer (60) and the inner sheath layer (710), and / or between the inner sheath layer (710) and the outer sheath layer (720).

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