Polyethylene cable material and preparation method thereof

Abstract

The invention relates to the technical field of cable manufacturing, and discloses a polyethylene cable material and a preparation method thereof. Aiming at the problem that the wear resistance, mechanical property and aging resistance of the existing polyethylene cable material are difficult to synergistically optimize, the cable sequentially comprises a conductor, an insulating layer, a reinforcing layer and a sheath layer from inside to outside. The insulating layer is synergistically enhanced by silane coupling agent KH550 modified talcum powder and carbon nanotube / titanium dioxide composite powder, and is matched with high-density polyethylene and other base materials; the reinforcing layer is of a glass fiber, polyamide fiber and basalt fiber ternary mixed weaving structure, and the impregnation liquid is an epoxy resin and phenolic resin compound system; and the sheath layer is formed by compounding low-density polyethylene, fluoroplastic and wear-resistant powder. The method is suitable for complex scenes such as chemical engineering, outdoor and frequent mechanical wear, and has prominent practicability and popularization value.

Description

Technical Field

[0001] This invention relates to the field of cable manufacturing technology, specifically to a polyethylene cable material and its preparation method. Background Technology

[0002] Polyethylene cable materials are widely used in industrial production, construction engineering, transportation, and other fields due to their light weight, good insulation performance, and moderate cost. However, in complex working environments, such as chemical plants, harsh outdoor environments, and scenarios with frequent mechanical wear, ordinary polyethylene cable materials have significant shortcomings.

[0003] In existing technologies, to improve the wear resistance and corrosion resistance of polyethylene cable materials, conventional inorganic fillers such as talc and calcium carbonate are usually added to the polyethylene matrix, or simply compounded with fluoroplastics. However, conventional inorganic fillers have poor compatibility with the polyethylene matrix and are prone to agglomeration, resulting in limited improvement in the mechanical properties and wear resistance of the cable. While the addition of a single fluoroplastic can improve corrosion resistance, it increases material costs and cannot achieve a synergistic improvement in both wear resistance and mechanical strength.

[0004] Meanwhile, the reinforcement layers of existing cables mostly use single fibers or binary fiber braids, and the impregnation solution is mostly a single resin system, which makes it difficult to meet the requirements of cable structural stability and aging resistance in complex environments.

[0005] Furthermore, existing technologies lack the ability to synergistically apply specific modified inorganic fillers and composite powders to polyethylene cable materials, making it impossible to achieve comprehensive optimization of wear resistance, corrosion resistance, and mechanical properties. Therefore, in order to solve the above problems, a polyethylene cable material with more comprehensive performance and its preparation method are proposed. Summary of the Invention

[0006] This invention aims to provide a polyethylene cable material and its preparation method. Addressing the technical problems of insufficient wear resistance, limited corrosion resistance, and difficulty in synergistically optimizing mechanical and functional properties of existing polyethylene cable materials, this invention achieves a significant improvement in the overall performance of the cable through the synergistic effect of specific modified components, composite components, and the base material, combined with an optimized reinforcing layer structure and impregnation system.

[0007] To achieve the above objectives, the present invention provides the following technical solution: The technical solution provided by this invention is: A polyethylene cable material comprises, from the inside out, a conductor, an insulation layer, a reinforcing layer, and a sheath layer.

[0008] The insulation layer is composed of the following raw materials in parts by weight: 40-55 parts high-density polyethylene, 20-28 parts ultra-high molecular weight polyethylene, 3-8 parts polyether ether ketone micro powder, 2-6 parts aluminum nitride micro powder, 3-7 parts nano silica, 2-5 parts silane coupling agent KH550 modified talc powder, 1-3 parts maleic anhydride grafted polyethylene-styrene copolymer, 1-4 parts composite powder, 4-7 parts titanate coupling agent NDZ-311 modified sepiolite, and 3-6 parts nano boron nitride-polyimide powder. Among them, the number average molecular weight of ultra-high molecular weight polyethylene is 2.5 million to 5 million, and the particle size of polyether ether ketone micro powder is 5-20 μm; the particle size of aluminum nitride micro powder is 10-30 μm, and the particle size of nano silica is 20-45 nm; the mass ratio of carbon nanotubes to titanium dioxide in the composite powder is 1:9-2:8, and the particle size is 0.5-3 μm; the particle size of sepiolite modified with titanate coupling agent NDZ-311 is 1-5 μm; and the mass ratio of nano boron nitride to polyimide in nano boron nitride-polyimide powder is 2:8-3:7, and the particle size is 0.8-4 μm.

[0009] The reinforcing layer is a ternary hybrid layer of impregnated glass fiber, polyamide fiber and basalt fiber, with a mass ratio of 3:2:1-2:1:1. The weaving density of the reinforcing layer is 88%-95%, the thickness is 1.0-1.5mm, and the monofilament diameter of the basalt fiber is 8-15μm. The impregnation solution is a compound solution of epoxy resin and phenolic resin, with a weight ratio of 7:3-6:4 and a solid content of 40%-55%.

[0010] The sheath layer is composed of the following raw materials in parts by weight: 30-45 parts low-density polyethylene, 12-18 parts chlorinated polyethylene, 8-15 parts polyvinylidene fluoride, 3-5 parts polytetrafluoroethylene micro powder, 2-4 parts silicon carbide micro powder, and 2-3 parts nano zinc oxide; wherein the particle size of the silicon carbide micro powder is 8-25 μm.

[0011] The preparation method of silane coupling agent KH550 modified talc powder is as follows: talc powder is dried at 90-110℃ for 3-4 hours. The silane coupling agent KH550 is dissolved in anhydrous ethanol at a mass ratio of 100:4-100:6 to prepare a modification solution with a mass fraction of 6%-10%. The dried talc powder is added to the modification solution, and the mixture is stirred and reacted at 70-85℃ for 3-5 hours. After filtration, the mixture is dried at 110-120℃ for 4-6 hours and then ground through a 200-mesh sieve to obtain the final product.

[0012] The preparation method of the composite powder is as follows: weigh multi-walled carbon nanotubes and anatase titanium dioxide according to the proportion, add them to deionized water, and ultrasonically disperse for 40-80 min. The solid content of the dispersion liquid is 8%-12%. Then, stir and evaporate at 80-90℃ to a paste, transfer it to an oven and dry at 105-115℃ for 3-4 h, then place it in a muffle furnace and calcine at 400-500℃ for 2-3 h. After cooling, grind it through a 150-mesh sieve to obtain the final product.

[0013] The preparation method of sepiolite modified by titanate coupling agent NDZ-311 is as follows: The sepiolite is pulverized and passed through a 180-mesh sieve, then dried at 100-120℃ for 3-4 hours. The titanate coupling agent NDZ-311 is dissolved in anhydrous isopropanol at a mass ratio of 100:5-100:8 to prepare a modification solution with a mass fraction of 8%-12%. The dried sepiolite is added to the modification solution, and the mixture is stirred at a constant temperature of 75-90℃ for 4-6 hours. After filtration, the mixture is vacuum dried at 120-130℃ for 3-5 hours, and then ground through a 200-mesh sieve to obtain the final product.

[0014] The preparation method of nano boron nitride-polyimide powder is as follows: weigh nano boron nitride and polyimide powder according to the proportion, add them to N,N-dimethylformamide, add 0.8%-1.2% of polyethylene glycol 400 as a dispersant, ultrasonically disperse for 90-120 min, the solid content of the dispersion liquid is 12%-16%, stir and evaporate to gel state at 85-95℃, transfer to vacuum oven and dry at 130-140℃ for 5-6 h, then place in muffle furnace and calcine at 400-480℃ for 2-3 h, cool and grind through a 200 mesh sieve to obtain the powder.

[0015] The preparation method of this polyethylene cable material includes the following steps: S1. Raw material pretreatment: Dry each raw material of the insulation layer and the sheath layer at 85-100℃ for 2-3.5h respectively. Polyether ether ketone micro powder, aluminum nitride micro powder, silicon carbide micro powder, composite powder, titanate coupling agent NDZ-311 modified sepiolite, and nano boron nitride-polyimide powder are dried separately at 120-140℃ for 1-2h. S2. Insulation layer preparation: The dried insulation layer raw material is added to a twin-screw extruder and melt-mixed under the conditions of 145-155℃ in zone 1, 160-170℃ in zone 2, 175-185℃ in zone 3, and 180-190℃ at the die head. The screw speed of the twin-screw extruder is 35-48 r / min. The material is extruded and coated on the conductor to form an insulation layer. S3. Reinforcing layer coating: Glass fiber, polyamide fiber and basalt fiber are ternarily mixed and woven in proportion. The mixed fiber layer is immersed in the impregnation solution and treated at 90-100℃ for 12-18 min. After being taken out, it is dried at 110-120℃ for 30-60 min. The viscosity of the impregnation solution is 500-800 mPa·s. The impregnation amount of the mixed fiber layer is 20%-30% of the dry weight of the fiber layer. It is woven and wrapped around the outside of the insulation layer at a speed of 6-9 m / min to form a reinforcing layer. S4. Sheath layer preparation: The dried sheath layer raw material is added to a single-screw extruder and melt-mixed under the conditions of 135-145℃ in zone 1, 150-160℃ in zone 2, 165-175℃ in zone 3, and 170-180℃ at the die head. The screw speed of the single-screw extruder is 28-38 r / min. The material is extruded and coated on the outside of the reinforcing layer to form a sheath layer. S5. Crosslinking treatment: The coated cable is subjected to electron accelerator irradiation crosslinking treatment with an irradiation dose of 55-75kGy and an irradiation voltage of 110-140kV; S6. Cooling and shaping: The cross-linked cable is cooled in a cooling water tank at a temperature of 22-28℃ and then wound up to obtain the finished product.

[0016] The beneficial effects of this technical solution are: (1) The insulation layer uses silane coupling agent KH550 modified talc powder and titanate coupling agent NDZ-311 modified sepiolite as dual modifying components, combined with composite powder and nano boron nitride-polyimide powder as dual composite components, to form a quadruple synergistic reinforcement system. Silane coupling agent KH550 modified talc powder improves basic compatibility and mechanical strength, while titanate coupling agent NDZ-311 modified sepiolite, with its unique fibrous structure and coupling agent modification effect, further optimizes the dispersion of fillers in the substrate and strengthens the wear resistance and tear resistance of the insulation layer; the composite powder plays a synergistic role of mechanical and aging resistance of carbon nanotubes and titanium dioxide, while nano boron nitride-polyimide powder utilizes the high temperature thermal conductivity of boron nitride and the corrosion resistance and aging resistance of polyimide to fill the gap in the existing technology of wear resistance-corrosion resistance-high temperature resistance synergistic optimization. The synergistic effect of the four components avoids filler agglomeration and achieves a leapfrog improvement in the comprehensive performance of the insulation layer.

[0017] (2) The reinforcing layer adopts a ternary hybrid structure of glass fiber, polyamide fiber and basalt fiber, combined with epoxy resin and phenolic resin impregnation solution. The three fibers complement each other, and the composite adhesive solution has strong adhesion, which significantly improves the structural stability, tensile strength and peel resistance of the reinforcing layer, providing reliable structural support for the cable.

[0018] (3) The sheath layer is made by compounding low-density polyethylene, chlorinated polyethylene and polyvinylidene fluoride and polytetrafluoroethylene micro powder, combined with silicon carbide micro powder and nano zinc oxide to form a synergistic protection system, giving the cable excellent wear resistance, acid and alkali corrosion resistance and weather resistance. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the preparation steps of a polyethylene cable material and its preparation method proposed in this invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The specific implementation process is as follows: Example 1: Please see Figure 1 The present invention provides a technical solution: a polyethylene cable material and its preparation method, including raw material preparation: Insulation layer raw material weight: High-density polyethylene (model: Yanshan Petrochemical HDPE6100M) 45g, ultra-high molecular weight polyethylene (model: Shanghai Lianle UHMWPE-3500, number average molecular weight 3.5 million) 24g, polyether ether ketone micro powder 5g, aluminum nitride micro powder 4g, nano silica 5g, silane coupling agent KH550 modified talc powder 3g, maleic anhydride grafted polyethylene-styrene copolymer (model: Nanjing Sutai ST-2, grafting rate 1.2%) 2g, composite powder 2g, titanate coupling agent NDZ-311 modified sepiolite 5g, nano boron nitride-polyimide powder 4g; Among them, the number average molecular weight of ultra-high molecular weight polyethylene is 3.5 million, the particle size of polyether ether ketone micro powder is 12 μm, the particle size of aluminum nitride micro powder is 20 μm, the particle size of nano silica is 30 nm, the mass ratio of carbon nanotubes to titanium dioxide in the composite powder is 1.5:8.5, and the particle size is 1.5 μm; the particle size of sepiolite modified by titanate coupling agent NDZ-311 is 3 μm; the nano boron nitride-polyimide powder contains 1.2 g of nano boron nitride and 2.8 g of polyimide (mass ratio 3:7), and the particle size is 2 μm.

[0022] Reinforcing layer raw materials: 30g glass fiber, 20g polyamide fiber, 10g basalt fiber (mixing ratio 3:2:1), the monofilament diameter of basalt fiber is 12μm; the impregnation solution is a compound solution of 70g epoxy resin and 30g phenolic resin (weight ratio 7:3), the solid content of the compound solution is 48%.

[0023] Weight of raw materials for the sheath layer: 38g of low-density polyethylene (Yanshan Petrochemical LDPE1I60A), 15g of chlorinated polyethylene, 12g of polyvinylidene fluoride, 4g of polytetrafluoroethylene micro powder, 3g of silicon carbide micro powder, and 2.5g of nano zinc oxide; wherein the particle size of silicon carbide micro powder is 15μm.

[0024] Preparation of modified components: Silane coupling agent KH550 modified talc: Dry talc powder at 100℃ for 3.5h. Dissolve silane coupling agent KH550 in anhydrous ethanol at a mass ratio of 100:5 (60g talc powder, 3g KH550) to prepare a modification solution with a mass fraction of 8%. Add the dried talc powder to the modification solution and stir the reaction at 78℃ for 4h. After filtration, dry at 115℃ for 5h and grind through a 200-mesh sieve to obtain the final product.

[0025] Composite powder: Weigh the raw materials according to the mass ratio of 0.3g carbon nanotubes to 1.7g anatase titanium dioxide, add them to deionized water, ultrasonically disperse for 60min, the solid content of the dispersion is 10%, then stir and evaporate to a paste at 85℃, transfer to an oven and dry at 110℃ for 3.5h, then place in a muffle furnace and calcine at 450℃ for 2.5h, cool and grind through a 150-mesh sieve to obtain the final product.

[0026] Sepiolite modified with titanate coupling agent NDZ-311: Sepiolite was pulverized and passed through a 180-mesh sieve, then dried at 110℃ for 3.5h. A 10% (w / w) modification solution was prepared by dissolving NDZ-311 in anhydrous isopropanol at a mass ratio of 100:6 (100g sepiolite, 6g NDZ-311). The dried sepiolite was added to the modification solution, and the mixture was stirred at 82℃ for 5h. After filtration, the mixture was vacuum dried at 125℃ for 4h, and then ground through a 200-mesh sieve to obtain the final product.

[0027] Nano boron nitride-polyimide powder: Weigh the raw materials according to the mass ratio of 1.2g of nano boron nitride to 2.8g of polyimide, add them to N,N-dimethylformamide, add 1% of the total mass of polyethylene glycol 400 (0.04g) as a dispersant, ultrasonically disperse for 100min, the solid content of the dispersion is 14%, stir and evaporate at 90℃ to gel state, transfer to a vacuum oven and dry at 135℃ for 5.5h, then place in a muffle furnace and calcine at 450℃ for 2.5h, cool and grind through a 200-mesh sieve to obtain the powder.

[0028] Preparation steps S1. Raw material pretreatment: The raw materials for the insulation layer and the sheath layer are dried at 90℃ for 3 hours. Polyether ether ketone micro powder, aluminum nitride micro powder, silicon carbide micro powder, composite powder, titanate coupling agent NDZ-311 modified sepiolite, and nano boron nitride-polyimide powder are dried at 130℃ for 1.5 hours.

[0029] S2. Insulation layer preparation: The dried insulation layer raw material is added to a twin-screw extruder and melt-mixed under the conditions of 150℃ in zone 1, 165℃ in zone 2, 180℃ in zone 3 and 185℃ at the die head. The screw speed of the twin-screw extruder is 42r / min. The material is extruded and coated on the conductor to form an insulation layer.

[0030] S3. Reinforcing layer coating: The fiber layer is ternarily mixed and braided according to the mass ratio of 30g glass fiber, 20g polyamide fiber and 10g basalt fiber. The mixed fiber layer is immersed in the impregnation solution and treated at 95℃ for 15min. After being taken out, it is dried at 115℃ for 45min. The viscosity of the impregnation solution is 650mPa·s. The impregnation amount of the mixed fiber layer is 25% of the dry weight of the fiber layer. It is braided and wrapped on the outside of the insulation layer at a speed of 7.5m / min to form a reinforcing layer. The braiding density of the reinforcing layer is 92% and the thickness is 1.2mm.

[0031] S4. Sheath layer preparation: The dried sheath layer raw material is added to a single-screw extruder and melt-mixed under the conditions of 140℃ in zone 1, 155℃ in zone 2, 170℃ in zone 3 and 175℃ at the die head. The screw speed of the single-screw extruder is 33r / min. The material is extruded and coated on the outside of the reinforcing layer to form a sheath layer.

[0032] S5. Crosslinking treatment: The coated cable is subjected to electron accelerator irradiation crosslinking treatment with an irradiation dose of 65kGy and an irradiation voltage of 125kV.

[0033] S6. Cooling and molding: The cross-linked cable is cooled in a cooling water tank at a temperature of 25°C and then wound up to obtain the finished product.

[0034] Test Project Test Results Abrasion resistance (wear rate) 0.8mg Tensile strength 28MPa Elongation at break 420% Tensile strength retention rate after UV aging 89% Elongation at break retention rate after UV aging 85% The data sheet comprehensively covers the core performance indicators of the cable. In terms of abrasion resistance, the wear amount is only 0.8mg, indicating that the cable surface protection system can effectively resist mechanical friction loss. In terms of mechanical properties, the tensile strength reaches 28MPa and the elongation at break is 420%, achieving a synergistic balance between high strength and excellent toughness, meeting the structural load-bearing requirements under complex working conditions. The aging resistance performance is excellent, with the retention rate of tensile strength and elongation at break after ultraviolet aging both approaching 90%, indicating that the cable has excellent anti-aging stability during long-term outdoor use, and its service life is reliably guaranteed.

[0035] Example 2: Please see Figure 1 The present invention provides a technical solution: a polyethylene cable material and its preparation method, including raw material preparation: Insulation layer raw material weight: High-density polyethylene (model: Yanshan Petrochemical HDPE6100M) 55g, ultra-high molecular weight polyethylene (model: Shanghai Lianle UHMWPE-5000, number average molecular weight 50 million) 28g, polyether ether ketone micro powder 8g, aluminum nitride micro powder 6g, nano silica 7g, silane coupling agent KH550 modified talc powder 5g, maleic anhydride grafted polyethylene-styrene copolymer (model: Nanjing Sutai ST-2, grafting rate 1.2%) 3g, composite powder 4g, titanate coupling agent NDZ-311 modified sepiolite 7g, nano boron nitride-polyimide powder 6g; Among them, the number average molecular weight of ultra-high molecular weight polyethylene is 5 million, the particle size of polyether ether ketone micro powder is 20 μm, the particle size of aluminum nitride micro powder is 30 μm, the particle size of nano silica is 45 nm, the mass ratio of carbon nanotubes to titanium dioxide in the composite powder is 2:8 (0.8 g of carbon nanotubes and 3.2 g of titanium dioxide in the composite powder) and the particle size is 3 μm; the particle size of sepiolite modified by titanate coupling agent NDZ-311 is 5 μm; the nano boron nitride-polyimide powder contains 1.8 g of nano boron nitride and 4.2 g of polyimide (mass ratio 3:7) and the particle size is 4 μm.

[0036] Reinforcing layer raw materials: 25g glass fiber, 15g polyamide fiber and 10g basalt fiber (mixing ratio 2.5:1.5:1), the monofilament diameter of basalt fiber is 15μm; the impregnation solution is a compound solution of 65g epoxy resin and 35g phenolic resin (weight ratio 6.5:3.5), the solid content of the compound solution is 55%.

[0037] Weight of raw materials for the sheath layer: 45g of low-density polyethylene (Yanshan Petrochemical LDPE1I60A), 18g of chlorinated polyethylene, 15g of polyvinylidene fluoride, 5g of polytetrafluoroethylene micro powder, 4g of silicon carbide micro powder, and 3g of nano zinc oxide; among which, the particle size of silicon carbide micro powder is 25μm.

[0038] Preparation of modified components: Silane coupling agent KH550 modified talc: Dry talc at 110℃ for 4 hours. Dissolve silane coupling agent KH550 in anhydrous ethanol to prepare a 10% mass fraction modification solution according to the mass ratio of talc to silane coupling agent KH550 of 100:6 (100g talc, 6g KH550). Add the dried talc to the modification solution and stir at 85℃ for 5 hours. After filtration, dry at 120℃ for 6 hours and grind through a 200-mesh sieve to obtain the final product.

[0039] Composite powder: Weigh the raw materials according to the mass ratio of 0.8g carbon nanotubes to 3.2g anatase titanium dioxide, add them to deionized water, ultrasonically disperse for 80min, the solid content of the dispersion is 12%, then stir and evaporate to a paste at 90℃, transfer to an oven and dry at 115℃ for 4h, then place in a muffle furnace and calcine at 500℃ for 3h, cool and grind through a 150-mesh sieve to obtain the final product.

[0040] Sepiolite modified with titanate coupling agent NDZ-311: Sepiolite was pulverized and passed through a 180-mesh sieve, then dried at 120℃ for 4 hours. A 12% mass fraction modification solution was prepared by dissolving the titanate coupling agent NDZ-311 in anhydrous isopropanol at a mass ratio of 100:8 (100g sepiolite, 8g NDZ-311). The dried sepiolite was added to the modification solution, and the mixture was stirred at 90℃ for 6 hours. After filtration, the mixture was vacuum dried at 130℃ for 5 hours and then ground through a 200-mesh sieve to obtain the final product.

[0041] Nano boron nitride-polyimide powder: Weigh the raw materials according to the mass ratio of 1.8g of nano boron nitride to 4.2g of polyimide, add them to N,N-dimethylformamide, add 1.2% of the total mass of polyethylene glycol 400 (0.072g) as a dispersant, ultrasonically disperse for 120min, the solid content of the dispersion is 16%, stir and evaporate at 95℃ to gel state, transfer to a vacuum oven and dry at 140℃ for 6h, then place in a muffle furnace and calcine at 480℃ for 3h, cool and grind through a 200-mesh sieve to obtain the powder.

[0042] Preparation steps S1. Raw material pretreatment: Each raw material of the insulation layer and the sheath layer is dried at 100℃ for 3.5h. Polyether ether ketone micro powder, aluminum nitride micro powder, silicon carbide micro powder, composite powder, titanate coupling agent NDZ-311 modified sepiolite, and nano boron nitride-polyimide powder are dried at 140℃ for 2h.

[0043] S2. Insulation layer preparation: The dried insulation layer raw material is added to a twin-screw extruder and melt-mixed under the conditions of 155℃ in zone 1, 170℃ in zone 2, 185℃ in zone 3 and 190℃ at the die head. The screw speed of the twin-screw extruder is 48r / min. The material is extruded and coated on the conductor to form an insulation layer.

[0044] S3. Reinforcing layer coating: The fiber layer is ternarily mixed and braided according to the mass ratio of 25g glass fiber, 15g polyamide fiber and 10g basalt fiber. The mixed fiber layer is immersed in the above-mentioned compound impregnation solution and treated at 100℃ for 18min. After being taken out, it is dried at 120℃ for 60min. The viscosity of the impregnation solution is 800mPa·s. The impregnation amount of the mixed fiber layer is 30% of the dry weight of the fiber layer. It is braided and wrapped around the insulation layer at a speed of 9m / min to form a reinforcing layer. The braiding density of the reinforcing layer is 95% and the thickness is 1.5mm.

[0045] S4. Sheath layer preparation: The dried sheath layer raw material is added to a single-screw extruder and melt-mixed under the conditions of 145℃ in zone 1, 160℃ in zone 2, 175℃ in zone 3 and 180℃ at the die head. The screw speed of the single-screw extruder is 38r / min. The material is extruded and coated on the outside of the reinforcing layer to form a sheath layer.

[0046] S5. Crosslinking treatment: The coated cable is subjected to electron accelerator irradiation crosslinking treatment with an irradiation dose of 75kGy and an irradiation voltage of 140kV.

[0047] S6. Cooling and molding: The cross-linked cable is cooled in a cooling water tank at a temperature of 28°C and then wound up to obtain the finished product.

[0048] Test Project Test Results Abrasion resistance (wear rate) 0.6mg Tensile strength 32MPa Elongation at break 400% Tensile strength retention rate after UV aging 91% Elongation at break retention rate after UV aging 87% The performance indicators presented in this data sheet represent the best levels among all embodiments. It exhibits outstanding abrasion resistance, with an abrasion amount of only 0.6 mg, demonstrating the synergistic strengthening effect of the high-content abrasion-resistant filler and the substrate. In terms of mechanical properties, the tensile strength reaches 32 MPa, providing the cable with extremely strong structural load-bearing capacity. Even with a 400% elongation at break, it maintains good toughness, adapting to deformation requirements during installation and use. It also demonstrates excellent aging resistance, with all properties retaining over 87% after UV aging, including a 91% retention rate of tensile strength. This proves the synergistic effect of the high-content anti-aging components and the cross-linking process, effectively resisting the erosion of harsh outdoor environments and ensuring the long-term stable operation of the cable.

[0049] Example 3: Please see Figure 1 The present invention provides a technical solution: a polyethylene cable material and its preparation method, including raw material preparation: Insulation layer raw material weight: High-density polyethylene 40g (model: Yanshan Petrochemical HDPE6100M), ultra-high molecular weight polyethylene 20g (model: Shanghai Lianle UHMWPE-2500, number average molecular weight 2.5 million), polyether ether ketone micro powder 3g, aluminum nitride micro powder 2g, nano silica 3g, silane coupling agent KH550 modified talc powder 2g, maleic anhydride grafted polyethylene-styrene copolymer (model: Nanjing Sutai ST-2, grafting rate 1.2%) 1g, composite powder 1g, titanate coupling agent NDZ-311 modified sepiolite 4g, nano boron nitride-polyimide powder 3g; Among them, the number average molecular weight of ultra-high molecular weight polyethylene is 2.5 million, the particle size of polyether ether ketone micro powder is 5 μm, the particle size of aluminum nitride micro powder is 10 μm, the particle size of nano silica is 20 nm, the mass ratio of carbon nanotubes to titanium dioxide in the composite powder is 1:9, and the particle size is 0.5 μm; the particle size of sepiolite modified by titanate coupling agent NDZ-311 is 1 μm; the nano boron nitride-polyimide powder contains 0.6 g of nano boron nitride and 2.4 g of polyimide (mass ratio 2:8), and the particle size is 0.8 μm.

[0050] Reinforcing layer materials: 20g glass fiber, 10g polyamide fiber and 10g basalt fiber (mixing ratio 2:1:1), the monofilament diameter of basalt fiber is 8μm; the impregnation solution is a compound solution of 60g epoxy resin and 40g phenolic resin (weight ratio 6:4), the solid content of the compound solution is 40%.

[0051] The weight of the raw materials for the sheath layer is as follows: 30g of low-density polyethylene (Yanshan Petrochemical LDPE1I60A), 12g of chlorinated polyethylene, 8g of polyvinylidene fluoride, 3g of polytetrafluoroethylene micro powder, 2g of silicon carbide micro powder, and 2g of nano zinc oxide; among which, the particle size of silicon carbide micro powder is 8μm.

[0052] Preparation of modified components: Silane coupling agent KH550 modified talc: Dry talc powder at 90℃ for 3 hours. Dissolve silane coupling agent KH550 in anhydrous ethanol to prepare a 6% (w / w) modification solution at a mass ratio of 100:4 (100g talc powder, 4g KH550). Add the dried talc powder to the modification solution and stir at 70℃ for 3 hours. After filtration, dry at 110℃ for 4 hours and grind through a 200-mesh sieve to obtain the final product.

[0053] Composite powder: Weigh the raw materials according to the mass ratio of 0.1g carbon nanotubes to 0.9g anatase titanium dioxide, add them to deionized water, ultrasonically disperse for 40min, the solid content of the dispersion is 8%, then stir and evaporate to a paste at 80℃, transfer to an oven and dry at 105℃ for 3h, then place in a muffle furnace and calcine at 400℃ for 2h, cool and grind through a 150-mesh sieve to obtain the final product.

[0054] Sepiolite modified with titanate coupling agent NDZ-311: Sepiolite was pulverized and passed through a 180-mesh sieve, then dried at 100℃ for 3 hours. A modification solution with a mass ratio of NDZ-311 of 100:5 (100g sepiolite, 5g NDZ-311) was prepared by dissolving NDZ-311 in anhydrous isopropanol. The dried sepiolite was added to the modification solution, and the mixture was stirred at 75℃ for 4 hours. After filtration, the mixture was vacuum dried at 120℃ for 3 hours and then ground through a 200-mesh sieve to obtain the final product.

[0055] Nano boron nitride-polyimide powder: Weigh the raw materials according to the mass ratio of 0.6g of nano boron nitride to 2.4g of polyimide, add them to N,N-dimethylformamide, add 0.8% of the total mass of polyethylene glycol 400 (0.024g) as a dispersant, ultrasonically disperse for 90min, the solid content of the dispersion is 12%, stir and evaporate at 85℃ to gel state, transfer to a vacuum oven and dry at 130℃ for 5h, then place in a muffle furnace and calcine at 400℃ for 2h, cool and grind through a 200-mesh sieve to obtain the powder.

[0056] Preparation steps S1. Raw material pretreatment: The raw materials for the insulation layer and the sheath layer are dried at 85℃ for 2 hours. Polyether ether ketone micro powder, aluminum nitride micro powder, silicon carbide micro powder, composite powder, titanate coupling agent NDZ-311 modified sepiolite, and nano boron nitride-polyimide powder are dried at 120℃ for 1 hour each.

[0057] S2. Insulation layer preparation: The dried insulation layer raw material is added to a twin-screw extruder and melt-mixed under the conditions of 145℃ in zone 1, 160℃ in zone 2, 175℃ in zone 3 and 180℃ at the die head. The screw speed of the twin-screw extruder is 35r / min. The material is extruded and coated on the conductor to form an insulation layer.

[0058] S3. Reinforcing layer coating: The fiber layer is ternarily mixed and braided according to the mass ratio of 20g glass fiber, 10g polyamide fiber and 10g basalt fiber. The mixed fiber layer is immersed in the above-mentioned compound impregnation solution and treated at 90℃ for 12min. After being taken out, it is dried at 110℃ for 30min. The viscosity of the impregnation solution is 500mPa·s. The impregnation amount of the mixed fiber layer is 20% of the dry weight of the fiber layer. It is braided and wrapped on the outside of the insulation layer at a speed of 6m / min to form a reinforcing layer. The braiding density of the reinforcing layer is 88% and the thickness is 1.0mm.

[0059] S4. Sheath layer preparation: The dried sheath layer raw material is added to a single-screw extruder and melt-mixed under the conditions of 135℃ in zone 1, 150℃ in zone 2, 165℃ in zone 3 and 170℃ at the die head. The screw speed of the single-screw extruder is 28r / min. The material is extruded and coated on the outside of the reinforcing layer to form a sheath layer.

[0060] S5. Crosslinking treatment: The coated cable is subjected to electron accelerator irradiation crosslinking treatment with an irradiation dose of 55 kGy and an irradiation voltage of 110 kV. S6. Cooling and molding: The crosslinked cable is cooled in a cooling water bath at 22°C and then wound up to obtain the finished product.

[0061] Test Project Test Results Abrasion resistance (wear rate) 1.0mg Tensile strength 24MPa Elongation at break 450% Tensile strength retention rate after UV aging 86% Elongation at break retention rate after UV aging 82% The data table reflects the cable performance level under low-ratio raw materials and process parameters. Although the overall indicators are slightly lower than those of Examples 1 and 2, they are still significantly better than existing conventional technologies. In terms of abrasion resistance, the abrasion amount is 1.0 mg, which meets the requirements of general friction environments. Regarding mechanical properties, the tensile strength is 24 MPa, the elongation at break is 450%, and the toughness is outstanding, making it suitable for installation scenarios with high flexibility requirements. In terms of aging resistance, the retention rate of all properties after UV aging exceeds 82%, ensuring a basic service life in outdoor environments. This formula has good cost-effectiveness and is suitable for applications with moderate performance requirements.

[0062] Comparative Example 1: Please see Figure 1 The present invention provides a comparative scheme: Compositional differences: The silane coupling agent KH550 modified talc in the insulating layer was replaced with unmodified talc, and the rest was the same as in Example 1.

[0063] Key component preparation differences: The preparation steps of talc modified with silane coupling agent KH550 are the same as in Example 1.

[0064] Preparation steps: Same as in Example 1.

[0065] Test Project Test Results Abrasion resistance (wear rate) 2.5mg Tensile strength 20MPa Elongation at break 350% Tensile strength retention rate after UV aging 72% Elongation at break retention rate after UV aging 68% The data table clearly presents the negative impact of unmodified talc on cable performance. Abrasion resistance is significantly reduced, with an abrasion amount of 2.5 mg, more than three times that of Example 1, indicating poor compatibility between unmodified talc and the polyethylene substrate, leading to easy agglomeration and inability to form an effective abrasion-resistant protective structure. Mechanical properties are significantly insufficient, with a tensile strength of 20 MPa and an elongation at break of 350%, lower than the performance level of Example 1. This proves that unmodified talc not only fails to enhance the strength of the substrate but also disrupts its continuity due to agglomeration. Aging resistance is poor, with the retention rate of all properties after UV aging below 75%, further indicating that filler agglomeration leads to internal stress concentration in the material, accelerating the aging and degradation process.

[0066] Comparative Example 2: Please see Figure 1 The present invention provides a comparative scheme: Material difference: The reinforcing layer is replaced with a single glass fiber woven layer, otherwise it is the same as in Example 1.

[0067] Preparation of modified components: Same as in Example 1.

[0068] Differences in preparation steps: In the S3 reinforcement layer coating, only the ternary mixed fiber layer is replaced with a single glass fiber woven layer, and the rest is the same as in Example 1.

[0069] Test Project Test Results Abrasion resistance (wear rate) 1.5mg Tensile strength 22MPa Elongation at break 320% Tensile strength retention rate after UV aging 78% Elongation at break retention rate after UV aging 74% The data table illustrates the limitations of a single glass fiber reinforcement layer on cable performance. Abrasion resistance decreased compared to Example 1, with an abrasion amount of 1.5 mg, 1.8 times that of Example 1. This is due to the lack of the synergistic effect of the toughness of polyamide fibers and the abrasion resistance of basalt fibers, resulting in insufficient friction resistance of the reinforcement layer. Mechanical properties also showed shortcomings, with a tensile strength of 22 MPa and an elongation at break of 320%, lower than Example 1. This indicates that single glass fibers are brittle and cannot balance strength and toughness, while ternary hybrid fibers can improve overall mechanical properties through complementary advantages. Aging resistance was poor, with the retention rate of all properties below 80% after UV aging, proving that the aging resistance of single fibers is limited, while the synergistic effect of multiple fibers can effectively improve the aging stability of the material.

[0070] Comparative Example 3: Please see Figure 1 The present invention provides a comparative scheme: Differences in raw materials: The reinforcing layer impregnation solution was replaced with a single epoxy resin, the solid content was maintained at 48%, and the rest was the same as in Example 1.

[0071] Preparation of modified components: Same as in Example 1.

[0072] Differences in preparation steps: In the S3 reinforcement layer coating, only the compound impregnation solution is replaced with a single epoxy resin impregnation solution, and the rest is the same as in Example 1.

[0073] Test Project Test Results Abrasion resistance (wear rate) 1.4mg Tensile strength 23MPa Elongation at break 330% Tensile strength retention rate after UV aging 80% Elongation at break retention rate after UV aging 76% The data table reflects the adverse effects of a single epoxy resin impregnation solution on cable performance. Abrasion resistance is lower than in Example 1, with an abrasion amount of 1.4 mg. This is because the single epoxy resin is brittle and has insufficient interfacial bonding with the fiber, failing to form a continuous and stable abrasion-resistant protective structure. Mechanical properties are also inferior to Example 1, with a tensile strength of 23 MPa and an elongation at break of 330%, indicating that a single epoxy resin cannot balance adhesion and toughness, thus limiting the structural support of the reinforcing layer. Aging resistance is slightly worse, with the retention rate of all properties after UV aging below 85%, proving that the aging resistance of a single resin system is weaker than that of a compound system of epoxy and phenolic resins. The compound solution can improve the aging stability of the material through synergistic component composition.

[0074] Comparative Example 4: Please see Figure 1 The present invention provides a comparative scheme: Differences in raw materials: The composite powder is removed from the insulating layer, and the rest is the same as in Example 1.

[0075] Preparation of modified components: The preparation steps for the non-composite powder are the same as in Example 1.

[0076] Differences in preparation steps: In the pretreatment of raw materials S1, there is no need to dry the composite powder separately; the rest is the same as in Example 1.

[0077] Test Project Test Results Abrasion resistance (wear rate) 1.8mg Tensile strength 22MPa Elongation at break 360% Tensile strength retention rate after UV aging 81% Elongation at break retention rate after UV aging 77% This data table clearly demonstrates the impact of the missing composite powder on cable performance. Abrasion resistance is significantly reduced, with an abrasion amount of 1.8 mg, 2.25 times that of Example 1. This indicates the lack of synergistic effect between the high mechanical properties of carbon nanotubes and the abrasion resistance of titanium dioxide, failing to further enhance the abrasion protection capability of the insulation layer. Mechanical properties are also insufficient, with a tensile strength of 22 MPa, lower than Example 1, proving that the reinforcing effect of carbon nanotubes on the substrate was not fully realized, affecting the overall structural strength of the cable. Aging resistance is slightly poor, with the retention rate of all properties after UV aging below 85%. This is because the anti-aging properties of titanium dioxide did not participate in the synergistic effect, leading to a decrease in the material's anti-aging stability, fully demonstrating the crucial role of composite powder in improving the overall performance of the cable.

[0078] Comparative Example 5: Please see Figure 1 The present invention provides a comparative scheme: Compositional differences: The titanate coupling agent NDZ-311 modified sepiolite and nano boron nitride-polyimide powder were removed from the insulating layer, and the rest were the same as in Example 1.

[0079] Key component preparation differences: No new modified components or composite powder preparation steps were added; otherwise, the preparation process was the same as in Example 1.

[0080] Preparation steps: Same as in Example 1.

[0081] Test Project Test Results Abrasion resistance (wear rate) 2.3mg Tensile strength 21MPa Elongation at break 360% Tensile strength retention rate after UV aging 73% Elongation at break retention rate after UV aging 69% This data clearly quantifies the comprehensive performance degradation of the cable when both the NDZ-311 titanate coupling agent-modified sepiolite and nano-boron nitride-polyimide powder are missing from the insulation layer. In terms of abrasion resistance, the wear rate spikes to 2.3 mg. This is because the fibrous structure of the modified sepiolite completely loses its abrasion-resistant support for the substrate, while the auxiliary abrasion-resistant effect of the nano-boron nitride-polyimide powder is absent, leading to the complete collapse of the abrasion-resistant protection system of the cable's outer sheath and insulation layer. Regarding mechanical properties, the tensile strength drops to 21 MPa. The core reason is the disappearance of the synergistic effect between the fiber reinforcement of the modified sepiolite and the mechanical skeleton of the composite powder, significantly weakening the substrate's load-bearing capacity. The aging resistance is the worst, with only 73% and 69% retention rates of tensile strength and elongation at break after UV aging, respectively. This confirms that the synergistic effect of the weather resistance of polyimide and the thermal stability of boron nitride in the nano-boron nitride-polyimide powder is indispensable. Their absence causes the cable to fail in UV aging resistance, further exposing the limitations of relying solely on titanium dioxide for aging resistance.

[0082] By comparing the performance data and technical solutions of Examples 1 to 3 with those of Comparative Examples 1 to 5, it can be clearly seen that the technical solution, through the synergistic effect of silane coupling agent KH550 modified talc powder, titanate coupling agent NDZ-311 modified sepiolite, carbon nanotube-titanium dioxide composite powder, and nano boron nitride-polyimide powder, completely solves the industry problem of poor compatibility and easy agglomeration between conventional inorganic fillers and polyethylene substrates. The insulation layers in Examples 1 to 3 are constructed based on this multi-component composite system. The wear resistance is only 0.6 mg (Example 2) to 1.0 mg (Example 3), the tensile strength is 24 MPa (Example 3) to 32 MPa (Example 2), and the performance retention rate after UV aging is 82% (Example 3) to 91% (Example 2). In contrast, when the modified talc powder in Comparative Example 1 was replaced with unmodified talc powder, the wear amount increased sharply to 2.5 mg, the tensile strength dropped to 20 MPa, and the tensile strength retention rate after UV aging was only 72%. This fully demonstrates that the bridging effect of the silane coupling agent can significantly improve the uniformity of filler dispersion and the bonding force with the substrate. At the same time, the high mechanical support of carbon nanotubes and the aging resistance of titanium dioxide, together with modified sepiolite and nano boron nitride-polyimide powder, form a multi-dimensional synergy, comprehensively optimizing the overall performance of the insulation layer. After removing the composite powder in Comparative Example 4, the wear amount increased to 1.8 mg and the tensile strength decreased to 22 MPa, further verifying that the composite powder is a key component for improving the core performance of the cable. However, the existing technology lacks the synergistic application of such multi-component modified fillers and functional composite powders.

[0083] Secondly, the reinforcing layer innovatively adopts a ternary hybrid structure of glass fiber-polyamide fiber-basalt fiber (hybrid ratio 2:1:1 to 3:2:1), combined with epoxy resin and phenolic resin impregnation solution (weight ratio 6:4 to 7:3), to construct a structural support system with high strength, high toughness and aging resistance, breaking through the limitations of single fiber or binary fiber hybrid weaving and single resin impregnation in the existing technology. In the embodiments, this system enables the cable to achieve a tensile strength of up to 32 MPa and maintain an elongation at break of over 400%. In Comparative Example 2, after using a single glass fiber reinforcement layer, the tensile strength dropped to 22 MPa, the elongation at break was only 320%, and the wear amount increased to 1.5 mg. The core reason is that the single glass fiber is brittle and lacks the toughness supplementation of polyamide fiber and the wear resistance synergy of basalt fiber. In Comparative Example 3, after using a single epoxy resin impregnation solution, the tensile strength was 23 MPa, the elongation at break was 330%, and the performance retention rate after UV aging was less than 80%, which confirms that the compounded adhesive solution can take into account both adhesion and toughness through component synergy, and solve the performance shortcomings of the single resin system.

[0084] Furthermore, the sheath layer is composed of a multi-component matrix of low-density polyethylene, chlorinated polyethylene, and polyvinylidene fluoride, combined with wear-resistant enhancements from polytetrafluoroethylene micropowder and silicon carbide micropowder, and aging-resistant assistance from nano-zinc oxide, forming a comprehensive protection system. In the examples, the sheath layer resulted in a minimum wear resistance of only 0.6 mg for the cable (Example 2), far superior to the comparative examples of 1.4 mg (Comparative Example 3) to 2.5 mg (Comparative Example 1), while ensuring performance stability after UV aging. In contrast, existing technologies often use a single matrix or simple fluoroplastic composites, making it difficult to achieve a balance between wear resistance, weather resistance, and cost.

[0085] Therefore, Examples 1 to 3 cover the full range of raw material ratios and process parameters: When Example 3 uses the lower limit ratio, the wear amount of 1.0 mg, tensile strength of 24 MPa, and tensile strength retention rate after UV aging of 86% are still significantly better than all comparative examples; When Example 2 uses the upper limit ratio, all performances are optimal, forming a complete product system from high cost-effectiveness to high performance. Compared with the prior art, this solution improves the cable wear resistance by 1.8 to 3 times, mechanical properties by 10% to 40%, and aging resistance by more than 10% through multi-dimensional innovative design of "modified filler + functional composite powder" synergy in the insulation layer, "ternary braiding + compound impregnation" reinforcement in the reinforcing layer, and "multi-substrate material + wear-resistant and aging-resistant additives" protection in the sheath layer. This completely solves the problem of insufficient performance of existing polyethylene cable materials in complex environments and provides reliable technical support for their application in complex scenarios such as chemical, outdoor, and frequent mechanical wear.

[0086] To further illustrate the beneficial technical effects of the polyethylene cable materials and their preparation methods in the various embodiments of the present invention, relevant performance tests were conducted on the polyethylene cable materials and their preparation methods involved in Examples 1-3 and Comparative Examples 1-4; the test methods are as follows: 1. Abrasion resistance: The wear of the cable sheath was measured after applying a 9 kPa load and rubbing for 10,000 cycles using a Martindale abrasion tester.

[0087] 2. Tensile strength and elongation at break: Prepare standard specimens and perform tensile tests at a speed of 50 mm / min. Record the tensile strength and elongation at break of the specimens.

[0088] 3. Performance retention rate after UV aging: The sample was placed in a UV aging chamber for 1000 hours, and then the tensile strength and elongation at break were tested. The ratio of the tensile strength and elongation at break was calculated with that of the unaged sample.

[0089] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific technical solutions or characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A polyethylene cable material, characterized in that, From the inside out, it consists of a conductor, an insulating layer, a reinforcing layer, and a sheath layer. The insulating layer is composed of the following raw materials in parts by weight: 40-55 parts high-density polyethylene, 20-28 parts ultra-high molecular weight polyethylene, 3-8 parts polyether ether ketone micro powder, 2-6 parts aluminum nitride micro powder, 3-7 parts nano silica, 2-5 parts talc modified with silane coupling agent KH-550, 1-3 parts maleic anhydride grafted polyethylene-styrene copolymer, 1-4 parts composite powder, 4-7 parts sepiolite modified with titanate coupling agent NDZ-311, and 3-6 parts nano boron nitride-polyimide powder. The ultra-high molecular weight polyethylene has a number average molecular weight of 2.5 million to 5 million, and the polyether ether ketone micro powder has a particle size of 5-20 μm. The aluminum nitride micro powder has a particle size of 10-30 μm, the nano silica has a particle size of 20-45 nm, and the silicon carbide micro powder has a particle size of 8-25 μm. The reinforcing layer is a ternary hybrid layer of impregnated glass fiber, polyamide fiber and basalt fiber, with a mass ratio of 3:2:1-2:1:

1. The weaving density of the reinforcing layer is 88%-95%, the thickness is 1.0-1.5mm, and the diameter of the basalt fiber filament is 8-15μm. The impregnation solution is a compound solution of epoxy resin and phenolic resin; The sheath layer is composed of the following raw materials in parts by weight: 30-45 parts low-density polyethylene, 12-18 parts chlorinated polyethylene, 8-15 parts polyvinylidene fluoride, 3-5 parts polytetrafluoroethylene micro powder, 2-4 parts silicon carbide micro powder, and 2-3 parts nano zinc oxide.

2. The polyethylene cable material according to claim 1, characterized in that, The preparation method of the silane coupling agent KH-550 modified talc powder is as follows: talc powder is dried at 90-110℃ for 3-4 hours. The silane coupling agent KH-550 is dissolved in anhydrous ethanol at a mass ratio of 100:4-100:6 to prepare a modification solution with a mass fraction of 6%-10%. The dried talc powder is added to the modification solution and stirred at 70-85℃ for 3-5 hours. After filtration, it is dried at 110-120℃ for 4-6 hours and then ground through a 200-mesh sieve to obtain the final product.

3. The polyethylene cable material according to claim 1, characterized in that, The composite powder has a carbon nanotube to titanium dioxide mass ratio of 1:9-2:8 and a particle size of 0.5-3μm.

4. The polyethylene cable material according to claim 3, characterized in that, The preparation method of the composite powder is as follows: weigh carbon nanotubes and anatase titanium dioxide according to the proportion, add them to deionized water, ultrasonically disperse for 40-80 min, the solid content of the dispersion liquid is 8%-12%, then stir and evaporate to a paste at 80-90℃, transfer to an oven and dry at 105-115℃ for 3-4 h, then place in a muffle furnace and calcine at 400-500℃ for 2-3 h, cool and grind through a 150 mesh sieve to obtain the final product.

5. The polyethylene cable material according to claim 1, characterized in that, The preparation method of the titanate coupling agent NDZ-311 modified sepiolite is as follows: sepiolite is pulverized and passed through a 180-mesh sieve, and dried at 100-120℃ for 3-4 hours. The titanate coupling agent NDZ-311 is dissolved in anhydrous isopropanol at a mass ratio of sepiolite to titanate coupling agent NDZ-311 of 100:5-100:8 to prepare a modification solution with a mass fraction of 8%-12%. The dried sepiolite is added to the modification solution and stirred at a constant temperature of 75-90℃ for 4-6 hours. After filtration, it is vacuum dried at 120-130℃ for 3-5 hours and then ground through a 200-mesh sieve to obtain the final product.

6. The polyethylene cable material according to claim 1, characterized in that, The mass ratio of boron nitride nanoparticles to polyimide in the boron nitride nanoparticles is 2:8-3:7, and the particle size is 0.8-4 μm.

7. The polyethylene cable material according to claim 6, characterized in that, The preparation method of the nano boron nitride-polyimide powder is as follows: weigh nano boron nitride and polyimide powder according to the proportion, add them to N,N-dimethylformamide, add 0.8%-1.2% of polyethylene glycol 400 as a dispersant, ultrasonically disperse for 90-120 min, the solid content of the dispersion liquid is 12%-16%, stir and evaporate to gel state at 85-95℃, transfer to a vacuum oven and dry at 130-140℃ for 5-6 h, then place in a muffle furnace and calcine at 400-480℃ for 2-3 h, cool and grind through a 200-mesh sieve to obtain the powder.

8. The polyethylene cable material according to claim 1, characterized in that, The weight ratio of epoxy resin to phenolic resin in the impregnation solution is 7:3-6:4, and the solid content of the compounded adhesive solution is 40%-55%.

9. A method for preparing polyethylene cable material as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Raw material pretreatment: Dry each raw material of the insulation layer and the sheath layer at 85-100℃ for 2-3.5h. Dry polyether ether ketone micro powder, aluminum nitride micro powder, silicon carbide micro powder, composite powder, titanate coupling agent NDZ-311 modified sepiolite, and nano boron nitride-polyimide powder separately at 120-140℃ for 1-2h. S2. Insulation layer preparation: The dried insulation layer raw material is added to a twin-screw extruder and melt-mixed under the conditions of 145-155℃ in zone 1, 160-170℃ in zone 2, 175-185℃ in zone 3, and 180-190℃ at the die head. The mixture is then extruded and coated onto the conductor to form an insulation layer. S3. Reinforcing layer coating: Glass fiber, polyamide fiber and basalt fiber are ternarily mixed and woven in proportion. The mixed fiber layer is immersed in the impregnation solution and treated at 90-100℃ for 12-18 minutes. After being taken out, it is dried at 110-120℃ for 30-60 minutes. It is then woven and wrapped around the outside of the insulation layer at a speed of 6-9m / min to form a reinforcing layer. S4. Sheath layer preparation: The dried sheath layer raw material is added to a single screw extruder and melt-mixed under the conditions of 135-145℃ in zone 1, 150-160℃ in zone 2, 165-175℃ in zone 3, and 170-180℃ at the die head. The mixture is then extruded and coated on the outside of the reinforcing layer to form the sheath layer. S5. Crosslinking treatment: The coated cable is subjected to electron accelerator irradiation crosslinking treatment with an irradiation dose of 55-75kGy and an irradiation voltage of 110-140kV; S6. Cooling and molding: The crosslinked cable is cooled in a cooling water tank at a temperature of 22-28℃ and then wound up to obtain the finished product.

10. The preparation method according to claim 9, characterized in that, In S2, the screw speed of the twin-screw extruder is 35-48 r / min, and in S4, the screw speed of the single-screw extruder is 28-38 r / min; in S3, the viscosity of the impregnation solution is 500-800 mPa・s, and the impregnation amount of the blended fiber layer is 20%-30% of the dry weight of the fiber layer.

Images