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CN-122025266-A - Environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable

CN122025266ACN 122025266 ACN122025266 ACN 122025266ACN-122025266-A

Abstract

The invention provides an environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable, relates to the technical field of cables, and solves the technical problems of material embrittlement, insufficient oxygen isolation, high-temperature resistance and unbalanced flexibility caused by high-filling flame retardant in the prior art. The cable sequentially comprises a copper alloy conductor, a nano compound insulating layer, a ceramic oxygen-insulating layer and a biobased LSZH sheath layer from inside to outside, wherein the material compound system realizes flame retardance and mechanical property balance through nano inorganic flame retardance and organic synergistic flame retardance and substrate modification, the doping of biobased PLA improves environmental protection, and the three-layer coextrusion and sectional gradient irradiation crosslinking are adopted to improve the production efficiency and the product consistency. The cable disclosed by the invention has the long-term working temperature of 150-180 ℃, the flame retardant grade reaches the class A of bunching, the smoke density is less than or equal to 100Dm, the tensile strength is more than or equal to 12MPa, the fire-resistant time is more than or equal to 180min, and the material cost is reduced by 10-15%.

Inventors

  • CHU QIANG
  • LV GUOWU
  • DONG PENGCHENG
  • NI GUOJUN
  • Zong Pi
  • YANG QIN

Assignees

  • 江苏华亚电缆有限公司

Dates

Publication Date
20260512
Application Date
20260327

Claims (10)

  1. 1. The environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable is characterized by sequentially comprising a copper alloy conductor, a nano compound insulating layer, a ceramic oxygen-insulating layer and a biobased LSZH sheath layer from inside to outside, wherein the nano compound insulating layer, the ceramic oxygen-insulating layer and the biobased LSZH sheath layer are synchronously formed through a three-layer coextrusion process; the nanometer compound insulating layer adopts a compound mode of nanometer inorganic flame retardance, organic synergistic flame retardance and substrate modification, the biobased LSZH sheath layer adopts a compound mode of biobased substrate, nanometer flame retardance and synergistic smoke suppression, and the biobased LSZH sheath layer and the nanometer flame retardance and the synergistic smoke suppression form a synergistic flame retardant material compound system; The ceramic oxygen-insulating layer is an extrusion ceramic silicon rubber oxygen-insulating layer, ceramic silicon rubber composite materials are adopted to be formed through extrusion molding, and the copper alloy conductor adopts a silver alloy modified and composite stranded structure to jointly form a cable structure adapting to a three-layer co-extrusion process; the three-layer coextrusion process is matched with the sectional gradient irradiation crosslinking process to form the process for adapting materials and structures.
  2. 2. The environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable as claimed in claim 1, wherein the specific formula of the material compounding system is as follows in parts by mass: the nano compound insulating layer comprises 35-45 parts of EVA/POE blending base material, 30-40 parts of nano ATH/MDH compound, 8-12 parts of phosphorus-nitrogen intumescent flame retardant, 6-10 parts of ceramic silicone rubber powder, 2-4 parts of compatilizer, 1-3 parts of antioxidant and 1-3 parts of lubricant; the particle size of the nanometer ATH/MDH is 50-100 nm, and the nanometer ATH/MDH is subjected to surface modification by silane KH 550; 30-40 parts of a biobased LSZH polyolefin substrate, 8-12 parts of biobased PLA, 25-35 parts of nano ATH/MDH compound, 4-6 parts of zinc borate and montmorillonite synergist, 4-6 parts of compatilizer, 2-4 parts of anti-aging additive and 1-3 parts of nano antiwear agent.
  3. 3. The environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable according to claim 2, wherein the biobased LSZH sheath layer is compounded by the following scheme: The bio-based PLA accounts for 8-12% of the total mass of the sheath layer, and the mechanical property of the sheath layer is not reduced after the bio-based PLA is blended with the LSZH polyolefin; The total ratio of zinc borate to montmorillonite synergist is 4-6%, and the mass ratio of the zinc borate to the montmorillonite synergist is 3:2, so that the smoke density is less than or equal to 100Dm when the sheath layer burns; the nanometer wear-resistant agent is nanometer silicon dioxide with the grain diameter less than or equal to 20nm, and the anti-aging auxiliary agent is a compound system of hindered phenol antioxidants and ultraviolet absorbers.
  4. 4. The environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable is characterized in that a phosphorus-nitrogen intumescent flame retardant in the nano compound insulating layer is a compound system of APP and MEL, the mass ratio of APP to MEL is 3:1-4:1, the polymerization degree of APP is more than or equal to 1000, the compatilizer is MAH-g-PE, and the grafting rate is 0.8-1.0%.
  5. 5. The environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable as claimed in claim 4, wherein the specific parameters of the cable structure are as follows: The copper alloy conductor is an alloy of oxygen-free copper and 0.1-0.3% of silver, adopts a composite stranded structure of beam stranding and compacting, has a filling coefficient of more than or equal to 95%, is plated with a nano tin layer on the surface, and has a plating thickness of less than or equal to 0.005mm; The thickness of the extruded ceramic silicon rubber oxygen-isolation layer is 0.3-0.5 mm, the porcelain forming temperature is more than or equal to 800 ℃, a compact ceramic body is rapidly formed after the fire is received, and the ceramic body is welded and attached with inner and outer layer materials after extrusion molding; And (3) interlayer bonding, namely sequentially and tightly bonding a nano compound insulating layer, a ceramic oxygen isolation layer and a biobased LSZH sheath layer, coating a compatilizer between the layers, and ensuring that the interlayer peeling strength is more than or equal to 3.0N/mm.
  6. 6. The environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable according to claim 5, wherein the thickness of the nano compound insulating layer is 0.8-1.2 mm, the thickness of the bio-based LSZH sheath layer is 1.0-1.5 mm, and the thickness ratio of the insulating layer to the sheath layer is 1:1.2-1:1.5.
  7. 7. The environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable is characterized by comprising a three-layer co-extrusion process, a mixing process and a crosslinking process, wherein the three-layer co-extrusion process comprises the following specific parameters of 160-170 ℃ of extrusion temperature of an insulating layer, 155-165 ℃ of extrusion temperature of a ceramic oxygen-insulating layer and 150-160 ℃ of extrusion temperature of a sheath layer; the compression ratio of the extrusion die is 3:1-5:1, the temperature control precision is +/-1 ℃, and the thickness deviation of each layer is less than or equal to +/-1%; and after extrusion, sectional cooling is adopted, wherein the cooling temperature of the first section is 60-70 ℃ and the cooling temperature of the second section is 30-40 ℃.
  8. 8. The environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable is characterized in that a material compounding system adopts a combination process of premixing at normal temperature for 10-15 min, banburying for 170-175 ℃ multiplied by 6-8 min and twin-screw mixing for 160-165 ℃ multiplied by 4-6 min, and the rotating speed of the twin screws is 450-550 r/min.
  9. 9. The environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable is characterized in that the crosslinking process is characterized in that the nano compound insulating layer is crosslinked by sectional gradient irradiation, the total irradiation dose is 100-120 kGy, and the crosslinking degree is more than or equal to 95%.
  10. 10. The environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable is characterized in that a three-layer co-extrusion screw extruder is adopted in the three-layer co-extrusion process, the length-diameter ratio of a screw is 25:1-30:1, the sectional type gradient irradiation crosslinking is divided into surface irradiation and inner layer irradiation, the surface irradiation dose is 80-90 kGy, and the inner layer irradiation dose is 110-120 kGy.

Description

Environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable Technical Field The invention relates to the technical field of wires and cables, in particular to an environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable. Background Along with the continuous improvement of the requirements of modern engineering on cable safety and environmental protection, the low-smoke halogen-free flame-retardant cable has become the preferred cable type in personnel-intensive places and industrial high-temperature environments due to the advantages of no halogen acid gas release and small smoke quantity during combustion. However, the existing low-smoke halogen-free flame-retardant cable still has a plurality of technical pain points in practical application: The existing cable is mostly dependent on inorganic flame retardants such as aluminum hydroxide (ATH), magnesium hydroxide (MDH) and the like to realize flame retardance, and the filling amount of the flame retardants is more than 60 percent to achieve the class A flame retardance grade of the bunching, so that the material is fragile and poor in bending resistance, and is easy to crack and damage in the laying process, so that the service life of the cable is influenced; the high-temperature resistance and the fire resistance are insufficient, namely the long-term working temperature of the conventional polyolefin base material is 125 ℃, the requirement of the high temperature of more than 150 ℃ for the scenes such as new energy, nuclear power and the like is difficult to meet, the oxygen isolation layer of the conventional cable is a metal belt or a common flame-retardant layer which is singly wrapped, the interlayer bonding degree is poor, flame is easy to spread from the interlayer, and the fire resistance time is only about 120 minutes generally; the environment protection performance and the cost control contradiction that the base materials of the existing cable are mostly petrochemical-based materials, the carbon footprint is large, and the high-end modified materials depend on import, so that the cost of the materials is higher; The production process has low efficiency and poor product consistency, the existing cable mostly adopts the step-by-step process of insulating layer extrusion, oxygen barrier layer wrapping and sheath layer extrusion, the production process is complicated, gaps are easy to generate between layers, and the nanometer flame retardant is easy to agglomerate in the mixing process, so that the fluctuation of the product performance is larger. In order to solve the problems, optimization is attempted in the industry through modification or structural adjustment of a single material, but synergistic improvement of flame retardant efficiency, high temperature resistance, mechanical properties, environmental protection and production efficiency cannot be realized. For example, patent CN108766488a discloses a low-smoke halogen-free flame-retardant cable, which improves flame retardant performance by adding an intumescent flame retardant, but still has the problems of higher filling amount of the flame retardant and insufficient temperature resistance level, and patent CN215496748U discloses a three-layer co-extrusion cable structure, which does not adapt to a nano compound flame-retardant system and a high-temperature-resistant material, has poor flame retardant and temperature-resistant synergistic effect, does not relate to application of a bio-based material, and has insignificant environmental protection and cost advantages. Disclosure of Invention The invention provides an environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable, which aims to solve the technical problems of unbalanced flame retardance and mechanical property, insufficient high-temperature resistance and fire resistance, contradiction between environment friendliness and cost control, low production process efficiency and poor product consistency. The technical scheme provided by the embodiment of the invention is as follows: the environment-friendly high-temperature-resistant low-smoke halogen-free flame-retardant cable provided by the embodiment of the invention sequentially comprises a copper alloy conductor, a nano compound insulating layer, a ceramic oxygen-insulating layer and a biobased LSZH sheath layer from inside to outside, wherein the nano compound insulating layer, the ceramic oxygen-insulating layer and the biobased LSZH sheath layer are synchronously formed through a three-layer coextrusion process; the nanometer compound insulating layer adopts a compound mode of nanometer inorganic flame retardance, organic synergistic flame retardance and substrate modification, the biobased LSZH sheath layer adopts a compound mode of biobased substrate, nanometer flame retardance and synergistic smoke suppression, and the biobased LSZH sheath layer and the nanometer f