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CN-122025236-A - Stretch-proofing insulated cable and preparation method thereof

CN122025236ACN 122025236 ACN122025236 ACN 122025236ACN-122025236-A

Abstract

The invention discloses a stretch-proofing insulated cable and a preparation method thereof, and relates to the technical field of cables. The stretch-resistant insulated cable comprises a conductor, an insulating layer, a shielding layer and a sheath layer, wherein the layers are prepared from raw materials in a specific proportion, the conductor is high-purity oxygen-free copper wires, the insulating layer takes polyolefin as a matrix, the shielding layer contains ethylene-vinyl acetate copolymer and conductive carbon black, the sheath layer is added with additives such as superfine talcum powder and the like, and the sheath layer is modified by multiple steps to optimize compatibility and dispersibility. The preparation is completed through layering mixing granulation, accurate extrusion coating, cooling and trimming, the technological parameters are controllable, the problems of poor compatibility of the existing cable components, easy aggregation of fillers and the like are solved, and the stretch resistance, insulation and ageing resistance are considered.

Inventors

  • HAO FUMIN
  • ZHENG JUNLING

Assignees

  • 河北兴航线缆有限公司

Dates

Publication Date
20260512
Application Date
20260309

Claims (10)

  1. 1. The stretch-proof insulated cable is characterized by comprising a conductor (1), an insulating layer (2), a shielding layer (3) and a sheath layer (4); Wherein the conductor is a high-purity oxygen-free copper wire; The insulating layer comprises the following raw materials, by weight, 75-85 parts of low-density polyethylene, 15-20 parts of homo-polypropylene, 2.5-4.0 parts of polypropylene grafted maleic anhydride, 2.5-4.0 parts of modified nano silicon dioxide, 1.0-1.5 parts of zinc stearate and 0.6-1.2 parts of compound antioxidant; the shielding layer comprises the following raw materials, by weight, 40-50 parts of ethylene-vinyl acetate copolymer, 25-35 parts of conductive carbon black N330, 8-12 parts of modified basalt fiber, 0.5-1.0 part of antioxidant 1010 and 0.5-1.0 part of zinc stearate; The sheath layer comprises the following raw materials, by weight, 55-65 parts of high-density polyethylene, 10-15 parts of low-density polyethylene, 10-15 parts of modified basalt fiber, 5-8 parts of ultrafine talcum powder, 2-3 parts of maleic anhydride grafted polyethylene, 1.0-1.5 parts of calcium stearate, 0.8-1.2 parts of compound antioxidant and 0.5-0.8 part of ultraviolet absorber UV-327.
  2. 2. A preparation method of a stretch-proof insulated cable is characterized by comprising the following steps: s1, feeding insulating layer materials into 50 Single screw extruder hopper, preheating the hopper to 100-110 ℃, setting the feeding section to 130-140 ℃, the melting section to 150-160 ℃, the homogenizing section to 180-190 ℃ and the die head to 190-200 ℃, keeping the temperature for 30min to ensure the temperature stability of each section; S2, introducing the conductor with the insulating layer A 35 single screw extruder, wherein a shielding layer material is added into a hopper and preheated to 95-105 ℃, a feeding section 135-145 ℃, a melting section 155-165 ℃, a homogenizing section 170-175 ℃ and a die head 175-180 ℃ are arranged, the traction speed is 4-5m/min, the thickness of a coated shielding layer is 0.3-0.5mm, and water cooling is carried out for 8min at 18-22 ℃ after coating, so that the shielding layer and an insulating layer are tightly attached, and a cable with the shielding layer is obtained; s3, introducing the cable with the shielding layer The method comprises the steps of adding sheath layer materials into a hopper of a 50 single-screw extruder, preheating to 90-100 ℃, starting a heating system of the extruder, setting a feeding section to 120-130 ℃, a melting section to 150-160 ℃, a homogenizing section to 180-190 ℃ and a die head to 190-200 ℃, setting a traction speed to 6-8m/min, coating the sheath with the thickness of 1.5-2.0mm, cooling the sheath cable to 15-20 ℃ for 15min, trimming, and winding to obtain a finished product of the stretch-resistant insulated cable.
  3. 3. The stretch-proof insulated cable of claim 1, wherein the insulation layer material is prepared by the following steps: Adding 75-85 parts of low-density polyethylene, 15-20 parts of homo-polypropylene, 2.5-4.0 parts of polypropylene grafted maleic anhydride and 1.0-1.5 parts of zinc stearate into a high-speed mixer, mixing for 5-6min at the rotating speed of 800-1000r/min and the temperature of 50-60 ℃, adding 2.5-4.0 parts of modified nano silicon dioxide and 0.6-1.2 parts of compound antioxidant, mixing for 3-4min at the rotating speed of 300-400r/min to obtain an insulation premix, adding the insulation premix into a double-screw extrusion granulator, setting the screw temperature of 170-190 ℃ and the rotating speed of 200-250r/min, extruding and granulating to obtain the granular insulation layer material with the particle size of 2-3 mm.
  4. 4. The stretch-proof insulated cable of claim 1, wherein the shielding layer material is prepared by the following steps: Adding 40-50 parts of ethylene-vinyl acetate copolymer, 25-35 parts of conductive carbon black N330, 0.5-1.0 part of antioxidant 1010 and 0.5-1.0 part of zinc stearate into a high-speed mixer, premixing for 5min at the rotating speed of 700-900r/min and the temperature of 60-70 ℃, slowly adding 8-12 parts of modified basalt fiber from a lateral charging port, continuously mixing for 8-10min to obtain shielding premix, adding the shielding premix into a double-screw extrusion granulator, setting the screw temperature to 140-160 ℃ and the rotating speed to 180-220r/min, extruding and granulating to obtain the granular shielding layer material with the particle size of 2-3 mm.
  5. 5. The stretch-proof insulated cable of claim 1, wherein the sheath material is prepared by the following steps: Adding 55-65 parts of high-density polyethylene, 10-15 parts of low-density polyethylene, 2-3 parts of maleic anhydride grafted polyethylene and 1.0-1.5 parts of calcium stearate into a high-speed mixer, mixing for 4-5min at the rotating speed of 600-800r/min and the temperature of 55-65 ℃, adding 5-8 parts of superfine talcum powder, continuously mixing for 3min, slowly adding 10-15 parts of modified basalt fiber into the mixture from a lateral feeding port, finally adding 0.8-1.2 parts of compound antioxidant and 0.5-0.8 part of ultraviolet absorbent UV-327, continuously mixing for 6-8min to obtain a sheath premix, adding the sheath premix into a double-screw extrusion granulator, setting the screw temperature of 170-190 ℃ and the rotating speed of 200-250r/min, and extruding and granulating to obtain the granular sheath layer material.
  6. 6. The stretch-proofing insulated cable according to claim 1, wherein the compound antioxidant is formed by compounding an antioxidant 1010 and an antioxidant 168 according to a mass ratio of 1:2.
  7. 7. The stretch-proofing insulated cable according to claim 1, wherein the modified basalt fiber is prepared by the following steps: A1, taking basalt fiber, adding deionized water, performing ultrasonic dispersion for 20-30min to remove surface impurities, adding an absolute ethanol solution containing 5wt.% of silane coupling agent KH-570 into the dispersion, regulating the pH value of a system to 4.0-5.0 by using acetic acid, stirring at a constant temperature of 60-70 ℃ for 1-1.5h, washing 3-4 times by using deionized water after filtering, and drying at 105-110 ℃ for 2-3h to obtain first modified basalt fiber; A2, adding pure toluene into the first modified basalt fiber, uniformly dispersing, introducing nitrogen for 30min to remove oxygen in the system, adding divinylbenzene and dibenzoyl peroxide, stirring and dissolving, preserving heat at 40-50 ℃ for 30min, heating to 75-85 ℃, preserving heat and stirring for 1-1.5h, cooling to room temperature, filtering, washing with toluene to remove free homopolymer, and vacuum drying at 80-90 ℃ to obtain the second modified basalt fiber; A3, taking the basalt fiber subjected to the second modification, adding the maleic anhydride grafted polyethylene wax, putting into a high-speed mixer, mixing for 20-30min at 80-90 ℃ and the rotating speed of 500-700r/min, cooling to room temperature, crushing, and sieving with a 100-mesh sieve to obtain the modified basalt fiber.
  8. 8. The stretch-proofing insulated cable according to claim 7, wherein the dosage ratio of basalt fiber, deionized water and absolute ethanol solution containing 5wt.% of silane coupling agent KH-570 in A1 is 100g:300-400g:60-80g, and the length of basalt fiber is 3-5mm; The dosage ratio of the first modified basalt fiber to the pure toluene to the divinylbenzene to the dibenzoyl peroxide in the A2 is 100g to 200-300g to 0.1-0.3g to 1-3g; The dosage ratio of the second modified basalt fiber to the maleic anhydride grafted polyethylene wax in the A3 is 100g:3-6g.
  9. 9. The stretch-proofing insulated cable according to claim 1, wherein the modified nano-silica is prepared by the following steps: B1, taking nano silicon dioxide, carrying out ultrasonic treatment on the nano silicon dioxide by 0.5wt.% of dilute hydrochloric acid for 10min, washing the nano silicon dioxide to be neutral by deionized water, carrying out vacuum drying at 110-120 ℃ for 3-4h, adding absolute ethyl alcohol, carrying out ultrasonic dispersion for 30-40min, adding an aluminate coupling agent DL-411, stirring at 65-75 ℃ for 1.3-1.7h, reducing the surface energy by primary coating of the aluminate, inhibiting agglomeration, and carrying out drying at 100-105 ℃ for 2-2.5h after filtering to obtain the first modified nano silicon dioxide; Adding xylene into the first modified nano silicon dioxide, performing ultrasonic dispersion for 20-30min, slowly dripping an absolute ethyl alcohol solution containing 5wt.% of silane coupling agent KH-570, heating to 80-90 ℃, stirring at constant temperature for 60min, cooling to 60-65 ℃, adding maleic anhydride, styrene and hydroquinone, stirring for 30min, continuously heating to 80-85 ℃, adding a benzoyl peroxide and xylene mixed solution, refluxing and stirring for 2-2.5h, cooling to room temperature after the completion, filtering and collecting solids, washing with toluene for 3 times, washing with absolute ethyl alcohol for 1 time, and performing vacuum drying at 90-100 ℃ for 1.5-2h to obtain second modified nano silicon dioxide; and B3, taking the second modified nano silicon dioxide, adding dimethylbenzene, performing ultrasonic dispersion for 20-30min, adding an antioxidant 1098, heating to 80-90 ℃, stirring for 60-80min, filtering, and performing vacuum drying at 80-90 ℃ for 1.5-2h to obtain the modified nano silicon dioxide.
  10. 10. The stretch-proofing insulated cable according to claim 9, wherein the dosage ratio of nano silicon dioxide, 0.5wt.% of dilute hydrochloric acid, absolute ethyl alcohol and aluminate coupling agent DL-411 in B1 is 50g:150-200g:200-300g:2-4g; The dosage ratio of the first modified nano silicon dioxide to the dimethylbenzene to the anhydrous ethanol solution containing 5wt.% of the silane coupling agent KH-570, the maleic anhydride, the styrene, the hydroquinone and the benzoyl peroxide in the B2 is 50g to 160 g to 210g to 40 g to 60g to 3 g to 5g to 9 g to 15g to 0.01 g to 0.02g to 0.8 g to 1.2g, wherein the dosage ratio of the first modified nano silicon dioxide to the dimethylbenzene used for dissolving the benzoyl peroxide is 150 g to 200g to 10g; The dosage ratio of the second modified nano silicon dioxide, the dimethylbenzene and the antioxidant 1098 in the B3 is 50g:100-150g:1.0-2.5g.

Description

Stretch-proofing insulated cable and preparation method thereof Technical Field The invention relates to the technical field of cables, in particular to a stretch-proof insulated cable and a preparation method thereof. Background In the technical field of cables, tensile resistance and insulation performance are core indexes for measuring the application range and service life of the cable, and particularly in complex working condition scenes such as power transmission and communication engineering, the cable often faces multiple tests such as installation and pulling, environmental corrosion and the like, and strict requirements are put on the comprehensive performance of materials. The research and development of the traditional stretch-proof insulated cable mainly surrounds the three major directions of matrix material optimization, reinforcing filler addition and process improvement. In the aspect of matrix materials, polyolefin materials such as polyethylene, polypropylene and the like are mostly adopted as base materials of an insulating layer and a sheath layer in the industry, and the materials have good insulativity and processing fluidity, but have insufficient mechanical strength, and the tensile resistance is required to be improved through blending modification. In the selection of the reinforcing filler, inorganic fillers such as basalt fiber, nano silicon dioxide and the like are widely applied due to the characteristics of high strength and high stability, wherein the basalt fiber is often directly added to the sheath layer and the shielding layer to enhance the mechanical property, and the nano silicon dioxide is mostly used for optimizing the structural compactness of the insulating layer. In the process, the main stream preparation mode is that mixing granulation and extrusion coating are combined, and the coating forming of each layer is realized by adjusting parameters such as screw temperature, traction speed and the like. However, the prior art still has a plurality of defects to be solved, namely, firstly, poor compatibility of components, inert surface of inorganic fillers such as basalt fibers, nano silicon dioxide and the like, insufficient affinity with polyolefin organic matrixes, uneven dispersion of the fillers in the matrixes, easy occurrence of agglomeration phenomenon, serious influence on mechanical properties and insulation stability of cables, secondly, difficult compromise between tensile and insulation properties, contradiction between the addition amount of reinforcing fillers and the insulation properties in the traditional formula, easy occurrence of defects in the insulation layers, reduction of breakdown strength and insulation resistance when the fillers are added to improve tensile strength, thirdly, insufficient ageing resistance, the conventional cables depend on single antioxidant or ultraviolet absorber to delay ageing, lack of a synergistic ageing-resistant system, easy oxidative degradation and photo-ageing of the materials under severe environments such as high temperature, strong ultraviolet and the like, reduced tensile strength, reduced elongation at break, shortened service life, and fourthly, poor process suitability, uneven dispersion of the fillers, loose interface bonding of each layer during extrusion coating and the like, further, and difficulty in meeting stable use requirements under complex working conditions. These problems limit the application scenario of the existing cable, and a technical scheme for combining component compatibility, mechanical property, insulation reliability and ageing resistance is needed. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a stretch-proof insulated cable and a preparation method thereof, and solves the problems that the existing cable material is poor in component compatibility, easy to agglomerate in filler, difficult to consider stretch-proof and insulating properties and insufficient in ageing resistance. In order to achieve the above purpose, the invention is realized by the following technical scheme: A stretch-proofing insulated cable comprises a conductor, an insulating layer, a shielding layer and a sheath layer; Wherein the conductor is a high-purity oxygen-free copper wire; The insulating layer comprises the following raw materials, by weight, 75-85 parts of low-density polyethylene, 15-20 parts of homo-polypropylene, 2.5-4.0 parts of polypropylene grafted maleic anhydride, 2.5-4.0 parts of modified nano silicon dioxide, 1.0-1.5 parts of zinc stearate and 0.6-1.2 parts of compound antioxidant; the shielding layer comprises the following raw materials, by weight, 40-50 parts of ethylene-vinyl acetate copolymer, 25-35 parts of conductive carbon black N330, 8-12 parts of modified basalt fiber, 0.5-1.0 part of antioxidant 1010 and 0.5-1.0 part of zinc stearate; The sheath layer comprises the following raw materials, by weight, 55-65 parts of high-density polye