An impact-resistant insulated sheathed cable

Abstract

The application relates to the technical field of cables and discloses an impact-resistant insulating sheath cable. The impact-resistant insulating sheath cable comprises, from inside to outside, a conductor, a shielding layer and an insulating layer. The insulating layer comprises the following components by weight: 50-70 parts of high-density polyethylene, 20-30 parts of polyolefin elastomer, 0.2-0.8 parts of surface-aminoized carbon nanotubes, 0.1-0.5 parts of cage polysilsesquioxane, 3-6 parts of a compatilizer, 0.5-2 parts of an antioxidant, 15-25 parts of a flame retardant and 0.5-1.5 parts of a lubricant. The surface-aminoized carbon nanotubes are modified through mixed acid oxidation, acyl chloride and the addition of ethylenediamine. The impact-resistant insulating sheath cable improves the impact resistance of the cable insulating layer, improves the agglomeration and interface bonding of nanofillers, makes the nanofillers uniformly dispersed in the polymer matrix, improves the mechanical strength and toughness of the material, and guarantees the electrical insulation properties.

Description

Technical Field

[0001] This invention relates to the field of cable technology, and more specifically, to an impact-resistant insulated sheathed cable. Background Technology

[0002] Impact-resistant insulated sheathed cables are special cables designed for power transmission in complex environments susceptible to mechanical impacts, compression, and other adverse conditions. They typically consist of key components such as a conductor, a shielding layer, and an insulation layer. The insulation layer, as the core protective layer, directly determines the cable's impact resistance, electrical insulation performance, and long-term reliability. The insulation layer is usually composed of a composite of various polymer materials and inorganic fillers.

[0003] In complex practical engineering applications, cables inevitably suffer from various complex external forces such as falling rocks, heavy object impacts, or mechanical dragging during the laying process. This requires the insulation material to have excellent toughness and impact resistance, and to absorb and dissipate energy when subjected to instantaneous high-intensity external forces without cracking or insulation failure, so as to adapt to harsh operating environments.

[0004] In existing technologies, blends of polyolefin elastomers and high-density polyethylene with carbon nanotubes are often used to improve sheath performance. However, carbon nanotubes are prone to aggregation due to van der Waals forces and have poor interfacial compatibility with non-polar polymer matrices. Under stress, stress concentration easily occurs at the interface, leading to insulation layer cracking and a decline in mechanical and electrical properties. To solve the above technical problems, this invention proposes a new impact-resistant insulated sheath cable. Summary of the Invention

[0005] This invention proposes an impact-resistant insulated sheathed cable, which aims to improve the overall performance of the cable through interfacial chemical cross-linking of molecules and synergistic energy dissipation between polymer matrices.

[0006] The technical solution of the present invention is as follows: In a first aspect, the present invention proposes an impact-resistant insulated sheathed cable, comprising, from the inside out, a conductor, a shielding layer, and an insulation layer. The insulation layer comprises the following raw materials in parts by weight: 50-70 parts of high-density polyethylene, 20-30 parts of polyolefin elastomer, 0.2-0.8 parts of surface-aminated carbon nanotubes, 0.1-0.5 parts of cage-like polysilsesquioxane, 3-6 parts of compatibilizer, 0.5-2 parts of antioxidant, 15-25 parts of flame retardant, and 0.5-1.5 parts of lubricant. The surface-aminated carbon nanotubes are obtained by mixed acid oxidation, followed by acyl chlorination and subsequent modification with the addition of ethylenediamine.

[0007] As a further technical solution, the preparation method of the surface-aminated carbon nanotubes includes: (1) Mixed acid oxidation: Carbon nanotubes are dispersed in a mixed solution of concentrated sulfuric acid and concentrated nitric acid, and ultrasonicated and stirred at 60~80℃ for 4~8h. After filtration, washing and drying, carboxylated carbon nanotubes are obtained. (2) First modification: The carboxylated carbon nanotubes were dispersed in thionyl chloride, N,N-dimethylformamide was added as a catalyst, and the reaction was refluxed at 60~80℃ for 6~10h. The solvent was removed by distillation, washed and dried to obtain acyl chloride carbon nanotubes. (3) Second modification: Disperse acyl chloride carbon nanotubes in toluene, add ethylenediamine, react at 90~110℃ for 8~12h, filter, wash and dry to obtain surface-aminated carbon nanotubes.

[0008] As a further technical solution, the volume ratio of concentrated sulfuric acid to concentrated nitric acid in the mixed solution is 3:1, and the mass-volume ratio of carbon nanotubes to the mixed solution is 1g:20~40mL.

[0009] As a further technical solution, the mass ratio of ethylenediamine to acyl chloride carbon nanotubes is 5~10:1.

[0010] In this invention, ethylenediamine is selected for surface amylation modification of carbon nanotubes. Compared with other long-chain ethylenediamines, the short-chain structure of ethylenediamine allows it to be densely grafted onto the surface of carbon nanotubes. These active terminal amino groups readily undergo ring-opening reactions with the epoxy groups on cage-like polysilsesquioxanes (POSS) during subsequent melt blending. This reaction truly achieves chemical bridging between carbon nanotubes and POSS, forming stable chemical bonds. Long-chain ethylenediamines not only have high steric hindrance but also easily crosslink between carbon nanotubes themselves, exacerbating aggregation. Therefore, choosing ethylenediamine can more effectively improve the compatibility between carbon nanotubes and the subsequent matrix.

[0011] As a further technical solution, the cage-shaped polysilsesquioxane is designated as EP0409.

[0012] As a further technical solution, the compatibilizer is maleic anhydride-grafted polyethylene.

[0013] As a further technical solution, the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1 to 2.

[0014] As a further technical solution, the flame retardant is a mixture of tetrabromobisphenol A and antimony trioxide in a mass ratio of 2 to 3:1.

[0015] As a further technical solution, the lubricant is zinc stearate or polyethylene wax.

[0016] As a further technical solution, the preparation steps of the impact-resistant insulated sheathed cable include: S1, covering the outer side of the conductor with shielding material to obtain a semi-finished product; S2, weighing the raw materials of each component of the insulation layer according to the weight, mixing them evenly, and then melting and granulating them through a twin-screw extruder to obtain an insulating material; S3, extruding the insulating material through an extruder to cover the outer side of the semi-finished product to form an insulation layer, thereby obtaining an impact-resistant insulated sheathed cable.

[0017] The working principle and beneficial effects of this invention are as follows: In this invention, a blend of polyolefin elastomer and high-density polyethylene is combined with surface-aminated carbon nanotubes, and cage-like polysilsesquioxane (POSS). The synergistic effect of these three components solves the problems of carbon nanotube agglomeration and poor interfacial compatibility in the prior art, while greatly improving the impact resistance of the cable sheath.

[0018] Specifically, firstly, although carbon nanotubes are conductive materials, this invention strictly controls their addition amount to an extremely low range of 0.2 to 0.8 parts. With this trace addition, the carbon nanotubes are completely encapsulated and isolated by the insulating polymer matrix, preventing the formation of continuous conductive pathways within the material. This ensures that the cable sheath maintains excellent electrical insulation performance while achieving mechanical reinforcement.

[0019] Secondly, the epoxy groups contained in the added cage-like polysilsesquioxane (POSS) can undergo a highly efficient epoxy-amine ring-opening reaction with the amino groups on the surface-aminated carbon nanotubes during melt blending, thereby firmly grafting POSS molecules onto the carbon nanotube surface. The organic side groups of the POSS molecules can effectively reduce the polarity of the carbon nanotube surface, hindering the aggregation between carbon nanotubes, and enabling them to achieve uniform dispersion at the nanoscale in the non-polar polyethylene and polyolefin elastomer blend matrix, thus effectively solving the problems of carbon nanotube aggregation and poor interfacial compatibility.

[0020] Thirdly, cage-like polysilsesquioxane possesses a unique rigid "cage-like" core structure of inorganic siloxanes. When the material is subjected to strong external mechanical impact, the flexible one-dimensional network structure composed of carbon nanotubes first undergoes elastic deformation to absorb energy. Simultaneously, the rigid POSS molecules connected to the carbon nanotubes by chemical bonds act as nanoscale damping nodes, dissipating impact energy to a great extent through micro-friction at the molecular level and stress dispersion of the cage-like structure. The one-dimensional network of carbon nanotubes and the three-dimensional rigid cage-like structure of POSS work perfectly together, endowing the insulation layer with a micro-network characteristic that combines rigidity and flexibility, thereby significantly improving the impact resistance of the cable sheath and enabling the cable insulation layer to exhibit excellent comprehensive performance when subjected to severe mechanical damage. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that the high-density polyethylene used in this invention was purchased from Dushanzi Petrochemical, with the grade DMDA-8008 and a melt flow index of 7.25 g / 10 min; The polyolefin elastomer was purchased from Dow Chemical, brand name Engage 8150; Maleic anhydride-grafted polyethylene was purchased from Nanjing Sutai Polymer Technology Co., Ltd., model number g-7. The carbon nanotubes were purchased from Shenzhen Nanoport Co., Ltd., model: L-MWNT-1020, with a diameter of 10~20nm and a length of 5~15μm. The cage-shaped polysilsesquioxane was purchased from Xi'an Qiyue Biotechnology Co., Ltd., with the brand name EP0409.

[0023] Example 1 This embodiment provides an impact-resistant insulated sheathed cable, which includes a copper conductor, a shielding layer, and an insulation layer from the inside out. The insulation layer includes the following raw materials in parts by weight: 60 parts high-density polyethylene, 25 parts polyolefin elastomer, 0.5 parts surface-aminated carbon nanotubes, 0.3 parts cage-like polysilsesquioxane, 4 parts maleic anhydride-grafted polyethylene, 1 part a mixture of antioxidant 1010 and antioxidant 168 (mass ratio 1:1), 20 parts a mixture of tetrabromobisphenol A and antimony trioxide (mass ratio 2:1), and 1 part zinc stearate. In this embodiment, the preparation steps of surface-aminated carbon nanotubes are as follows: (1) Disperse 10g of carbon nanotubes in 300mL of mixed acid solution (the volume ratio of concentrated sulfuric acid to concentrated nitric acid is 3:1), sonicate and stir at 70℃ for 6h, filter, wash with deionized water until neutral, and dry at 100℃ for 12h to obtain carboxylated carbon nanotubes. (2) Disperse 8g of carboxylated carbon nanotubes in 100mL of thionyl chloride, add 1mL of N,N-dimethylformamide, reflux at 70℃ for 8h, remove excess thionyl chloride by vacuum distillation, wash three times with anhydrous tetrahydrofuran, and vacuum dry at 80℃ for 10h to obtain acyl chloride carbon nanotubes. (3) Disperse 5g of acyl chloride carbon nanotubes in 200mL of toluene, add 35g of ethylenediamine, react at 100℃ for 10h, filter, wash three times with anhydrous ethanol, and vacuum dry at 80℃ for 12h to obtain surface-aminated carbon nanotubes. In this embodiment, the preparation steps of the impact-resistant insulated cable include: S1. Cover the outside of the copper conductor with a semi-conductive shielding material to obtain a semi-finished product; S2. Weigh the raw materials of each component of the insulation layer according to the weight, mix them evenly, and then melt-blend and granulate them at 190°C using a twin-screw extruder to obtain the insulation material; S3. The insulating material is extruded onto the outside of the semi-finished product through an extruder to form an insulating layer, resulting in an impact-resistant insulated sheathed cable.

[0024] Example 2 This embodiment provides an impact-resistant insulated sheathed cable, which includes a copper conductor, a shielding layer, and an insulation layer from the inside out. The insulation layer comprises the following raw materials in parts by weight: 50 parts high-density polyethylene, 30 parts polyolefin elastomer, 0.2 parts surface-aminated carbon nanotubes, 0.1 parts cage-like polysilsesquioxane, 3 parts maleic anhydride-grafted polyethylene, 1.2 parts antioxidant 1010 and 168 mixture (mass ratio 1:1.5), 15 parts tetrabromobisphenol A and antimony trioxide mixture (mass ratio 2.5:1), and 0.8 parts zinc stearate. In this embodiment, the preparation steps of surface-aminated carbon nanotubes are as follows: (1) 10g of carbon nanotubes were dispersed in 200mL of mixed acid solution (the volume ratio of concentrated sulfuric acid to concentrated nitric acid was 3:1), and ultrasonicated and stirred at 60℃ for 8h. After filtration, washing and drying, carboxylated carbon nanotubes were obtained. (2) 8g of carboxylated carbon nanotubes were dispersed in 80mL of thionyl chloride, and 0.8mL of N,N-dimethylformamide was added. The mixture was refluxed at 60℃ for 10h, and then distilled, washed and dried to obtain acyl chloride carbon nanotubes. (3) Disperse 5g of acyl chloride carbon nanotubes in 150mL of toluene, add 25g of ethylenediamine, react at 90℃ for 12h, filter, wash and dry to obtain surface-aminated carbon nanotubes.

[0025] In this embodiment, the preparation steps of the impact-resistant insulated cable include: S1. Cover the outside of the copper conductor with a semi-conductive shielding material to obtain a semi-finished product; S2. Weigh the raw materials of each component of the insulation layer according to the weight, mix them evenly, and then melt-blend and granulate them at 190°C using a twin-screw extruder to obtain the insulation material; S3. The insulating material is extruded onto the outside of the semi-finished product through an extruder to form an insulating layer, resulting in an impact-resistant insulated sheathed cable.

[0026] Example 3 This embodiment provides an impact-resistant insulated sheathed cable, which includes a copper conductor, a shielding layer, and an insulation layer from the inside out. The insulation layer comprises the following raw materials in parts by weight: 70 parts high-density polyethylene, 20 parts polyolefin elastomer, 0.8 parts surface-aminated carbon nanotubes, 0.5 parts cage-like polysilsesquioxane, 6 parts maleic anhydride-grafted polyethylene, 1.5 parts antioxidant 1010 and 168 mixture (mass ratio 1:2), 25 parts tetrabromobisphenol A and antimony trioxide mixture (mass ratio 3:1), and 1.2 parts polyethylene wax. In this embodiment, the preparation steps of surface-aminated carbon nanotubes are as follows: (1) 10g of carbon nanotubes were dispersed in 400mL of mixed acid solution (the volume ratio of concentrated sulfuric acid to concentrated nitric acid was 3:1), and ultrasonicated and stirred at 80℃ for 4h. After filtration, washing and drying, carboxylated carbon nanotubes were obtained. (2) 8g of carboxylated carbon nanotubes were dispersed in 120mL of thionyl chloride, and 1.2mL of N,N-dimethylformamide was added. The mixture was refluxed at 80℃ for 6h, and then distilled, washed and dried to obtain acyl chloride carbon nanotubes. (3) Disperse 5g of acyl chloride carbon nanotubes in 250mL of toluene, add 50g of ethylenediamine, react at 110℃ for 8h, filter, wash and dry to obtain surface-aminated carbon nanotubes.

[0027] In this embodiment, the preparation steps of the impact-resistant insulated cable include: S1. Cover the outside of the copper conductor with a semi-conductive shielding material to obtain a semi-finished product; S2. Weigh the raw materials of each component of the insulation layer according to the weight, mix them evenly, and then melt-blend and granulate them at 190°C using a twin-screw extruder to obtain the insulation material; S3. The insulating material is extruded onto the outside of the semi-finished product through an extruder to form an insulating layer, resulting in an impact-resistant insulated sheathed cable.

[0028] Comparative Example 1 The method is based on Example 1, but with the difference that the surface-aminated carbon nanotubes are replaced with an equal amount of carbon nanotubes.

[0029] Comparative Example 2 Based on Example 1, adjustments were made, the difference being that carboxylated carbon nanotubes of equal mass that were only treated with mixed acid oxidation were used to replace surface-aminolated carbon nanotubes. The preparation method of carboxylated carbon nanotubes treated only by mixed acid oxidation is only step (1) in Example 1.

[0030] Comparative Example 3 The method was adjusted based on Example 1. Unlike Example 1, no cage-like polysilsesquioxane was added, and 60.3 parts of high-density polyethylene were added.

[0031] Comparative Example 4 The method was adjusted based on Example 1. Unlike Example 1, no aminated carbon nanotubes were added, and 60.5 parts of high-density polyethylene were added.

[0032] Comparative Example 5 The method was adjusted based on Example 1, except that no polyolefin elastomer was added, and 85 parts of high-density polyethylene were added instead.

[0033] Comparative Example 6 The method is based on Example 1, but with the difference that the cage-shaped polysilsesquioxane is replaced with an equal mass of bisphenol A type epoxy resin (E-44).

[0034] Test Example 1: The impact-resistant insulated sheathed cables prepared in the aforementioned embodiments and comparative examples were subjected to the following tests: Tensile strength and elongation at break: Refer to GB / T 2951.11-2008, test speed 50 mm / min; Impact strength (cantilever beam notched impact strength): The specimen was tested according to GB / T 1843-2008, and the impact strength (kJ / m²) was recorded. 2 ); Volume resistivity: Refer to GB / T 31838.2-2019, test voltage 1000V; Flame retardant performance: The limiting oxygen index (LOI) was tested in accordance with GB / T 2406.2-2009. The test results are shown in Table 1 below: Table 1

[0035] Based on the aforementioned data, Examples 1-3 all exhibit excellent overall performance; even with a large amount of flame retardant added, the tensile strength remains between 21.8 and 25.2 MPa, the elongation at break is between 460% and 540%, and the notched impact strength of the cantilever beam reaches as high as 64.3 to 72.1 kJ / m. 2 The performance is significantly better than that of the conventional matrix (Comparative Example 4). This indicates that the insulating layer exhibits excellent mechanical reinforcement and impact resistance. Furthermore, comparing the volume resistivity reveals that although carbon nanotubes are inherently conductive, their addition inevitably leads to a decrease in the material's resistivity compared to the pure matrix (11.5 × 10⁻⁶ in Comparative Example 4). 15While the volume resistivity (Ω·cm) decreased, this application kept its dosage at an extremely low level. Furthermore, thanks to the chemical encapsulation and isolation of carbon nanotubes by the POSS insulating molecules, the volume resistivity of the embodiment remained at 3.2 × 10⁻⁶. 15 ~6.8×10 15 With an excellent insulation level of Ω·cm, it combines shock resistance with electrical insulation properties.

[0036] In Comparative Example 1, the original carbon nanotubes, without any surface modification, lacked active groups and had low polarity, making them prone to severe aggregation in polymers. Under stress, these aggregates became defects that triggered failure, leading to stress concentration. Consequently, the tensile strength plummeted to 17.5 MPa, and the impact strength was only 32.4 kJ / m². 2 Meanwhile, aggregated carbon nanotubes are more likely to form local conductive pathways, resulting in a significant drop in volume resistivity to 0.8 × 10⁻⁶. 15 Ω·cm. This indicates that the amination and subsequent modification of carbon nanotubes are crucial to their insulation and mechanical properties.

[0037] In Comparative Example 2, carboxylated carbon nanotubes treated only with mixed acid can improve dispersibility to some extent, but the surface lacks amino groups that can react efficiently with POSS ring-opening reaction, and cannot build a strong chemical bridging network. The overall performance is still significantly different from that of Example 1, indicating that complete amination modification is the basis for forming a high-strength interface.

[0038] Comparative Example 3 retained the surface-aminated carbon nanotubes but omitted the cage-like polysilsesquioxane (POSS). Although the aminated carbon nanotubes provided some reinforcement, the lack of the interfacial compatibilization and steric hindrance isolation effects of the POSS molecules resulted in a lower resistivity (1.5 × 10⁻⁶). 15 Ω·cm), and due to the lack of energy dissipation in the rigid cage-like core, its impact strength (45.2 kJ / m) is low. 2 The results were significantly lower than in Example 1, demonstrating that POSS is indispensable for addressing insulation isolation and dissipating impact energy.

[0039] Comparative Example 4 completely removed the surface-aminated carbon nanotubes, demonstrating the fundamental properties of the matrix material. Due to the lack of one-dimensional high-strength nanofillers and their reinforcing effect with the POSS crosslinking network, the insulating layer, although exhibiting the highest resistivity, had a tensile strength of only 18.0 MPa and an impact strength that dropped to 40.5 kJ / m². 2 This indicates that the three-dimensional network of carbon nanotubes is the cornerstone for improving mechanical and impact resistance properties.

[0040] Comparative Example 5 removed the polyolefin elastomer, and the insulation layer consisted entirely of a rigid matrix of high-density polyethylene. While the tensile strength was high, the elongation at break plummeted to 150%, and the impact strength was as low as 12.5 kJ / m. 2The material is extremely prone to brittle fracture upon impact. This demonstrates that the role of polyolefin elastomers in providing basic flexibility in formulations cannot be replaced.

[0041] In Comparative Example 6, ordinary bisphenol A type epoxy resin was used instead of POSS. Although ordinary epoxy resin also contains epoxy groups and can react with aminated carbon nanotubes to improve compatibility, it lacks the unique rigid inorganic silicon-oxygen cage structure of POSS and cannot function as a nanoscale damping node under mechanical impact. Its impact strength is only 52.6 kJ / m. 2 It is significantly lower than the 68.5 kJ / m³ of Example 1. 2 .

[0042] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An impact-resistant insulated sheathed cable, characterized in that, From the inside out, it comprises a conductor, a shielding layer, and an insulating layer. The insulating layer comprises the following raw materials in parts by weight: 50-70 parts of high-density polyethylene, 20-30 parts of polyolefin elastomer, 0.2-0.8 parts of surface-aminated carbon nanotubes, 0.1-0.5 parts of cage-like polysilsesquioxane, 3-6 parts of compatibilizer, 0.5-2 parts of antioxidant, 15-25 parts of flame retardant, and 0.5-1.5 parts of lubricant. The surface-aminated carbon nanotubes are obtained by mixed acid oxidation, followed by acyl chlorination and modification by the addition of ethylenediamine.

2. The impact-resistant insulated sheathed cable according to claim 1, characterized in that, The preparation method of the surface-aminated carbon nanotubes includes: (1) Mixed acid oxidation: Carbon nanotubes are dispersed in a mixed solution of concentrated sulfuric acid and concentrated nitric acid, and ultrasonicated and stirred at 60~80℃ for 4~8h. After filtration, washing and drying, carboxylated carbon nanotubes are obtained. (2) First modification: The carboxylated carbon nanotubes were dispersed in thionyl chloride, N,N-dimethylformamide was added as a catalyst, and the reaction was refluxed at 60~80℃ for 6~10h. The solvent was removed by distillation, washed and dried to obtain acyl chloride carbon nanotubes. (3) Second modification: The acyl chloride carbon nanotubes are dispersed in toluene, ethylenediamine is added, and the reaction is carried out at 90~110℃ for 8~12h. After filtration, washing and drying, surface-aminated carbon nanotubes are obtained.

3. The impact-resistant insulated sheathed cable according to claim 2, characterized in that, The volume ratio of concentrated sulfuric acid to concentrated nitric acid in the mixed solution is 3:1, and the mass-volume ratio of carbon nanotubes to the mixed solution is 1g:20~40mL.

4. The impact-resistant insulated sheathed cable according to claim 2, characterized in that, The mass ratio of ethylenediamine to acyl chloride carbon nanotubes is 5~10:

1.

5. The impact-resistant insulated sheathed cable according to claim 1, characterized in that, The cage-shaped polysilsesquioxane is designated as EP0409.

6. The impact-resistant insulated sheathed cable according to claim 1, characterized in that, The compatibilizer is maleic anhydride-grafted polyethylene.

7. The impact-resistant insulated sheathed cable according to claim 1, characterized in that, The antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1 to 2.

8. The impact-resistant insulated sheathed cable according to claim 1, characterized in that, The flame retardant is a mixture of tetrabromobisphenol A and antimony trioxide in a mass ratio of 2 to 3:

1.

9. The impact-resistant insulated sheathed cable according to claim 1, characterized in that, The lubricant is zinc stearate or polyethylene wax.

10. The impact-resistant insulated sheathed cable according to any one of claims 1-9, characterized in that, The preparation steps of the impact-resistant insulated sheathed cable include: S1, covering the outer side of the conductor with shielding material to obtain a semi-finished product; S2, weighing the raw materials of each component of the insulation layer according to the weight, mixing them evenly, and then melting, blending and granulating to obtain the insulation material; S3, extruding the insulation material onto the outer side of the semi-finished product to form an insulation layer, thereby obtaining the impact-resistant insulated sheathed cable.

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