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CN-122025270-A - High-flame-retardance temperature-resistant modified polyolefin low-voltage cable and preparation method thereof

CN122025270ACN 122025270 ACN122025270 ACN 122025270ACN-122025270-A

Abstract

The invention discloses a high-flame-retardant temperature-resistant modified polyolefin low-voltage cable and a preparation method thereof, relating to the technical field of cables and comprising a plurality of external installation conductors; the high-flame-retardant temperature-resistant modified polyolefin cable finished product is obtained by winding the cable after passing through a cooling water tank for cooling and drying after cross-linking, and then sequentially performing spark withstand voltage test and outer diameter measurement, thereby effectively inhibiting fire spreading and toxic smoke generation, greatly improving the fire safety level of a using place, ensuring the environmental protection level of a connecting place by a sealing ring design while realizing high flame retardance and high temperature resistance, facilitating overhaul by a bolt connection mode, and reducing the operation and maintenance cost and labor intensity of a full life cycle.

Inventors

  • Ran Cun
  • ZHAO YANJUN
  • PANG PENG
  • GAN LONGFEI
  • Ran ce
  • WANG JIANBO

Assignees

  • 河北英泰电气线缆有限公司

Dates

Publication Date
20260512
Application Date
20260306

Claims (10)

  1. 1. A high flame retardant temperature resistant modified polyolefin low voltage cable comprising: a plurality of external mounting conductors (11); an insulating inner layer (12) covering the plurality of external mounting conductors (11), and A sheath outer layer (1) coated outside the insulating inner layer (12); Wherein, the sheath outer layer (1) and the insulating inner layer (12) are both made of high flame-retardant temperature-resistant modified polyolefin composite materials.
  2. 2. The high-flame-retardant and temperature-resistant modified polyolefin low-voltage cable according to claim 1, wherein one end of the sheath outer layer (1) is provided with a joint end, the joint end is used for being connected with external equipment, the outer side of the sheath outer layer (1) is provided with a supporting end, and the supporting end is used for bearing the sheath outer layer (1).
  3. 3. The high-flame-retardant and temperature-resistant modified polyolefin low-voltage cable according to claim 2, wherein the joint (2) end comprises a joint (2) and a metal guide rod (21), a limiting block (22) is arranged at one end of each of the plurality of external installation conductors (11), the metal guide rod (21) is arranged at one end, close to the external installation conductor (11), of each limiting block (22), and an interface (25) is arranged at one end, far away from each limiting block (22), of the joint (2).
  4. 4. The high-flame-retardant and temperature-resistant modified polyolefin low-voltage cable according to claim 3, wherein a dust cover (23) is sleeved on the outer side of the interface (25), two symmetrically distributed first positioning bolts (24) are connected with the outer side of the dust cover (23) in a threaded mode, and mounting grooves matched with the interface (25) are formed in the outer side of the dust cover (23).
  5. 5. The high-flame-retardant and temperature-resistant modified polyolefin low-voltage cable according to claim 4, wherein the supporting end comprises a supporting frame (3) and an inner cavity (32), the supporting frame (3) is sleeved on the outer side of the outer sheath layer (1), a second sealing ring (37) extending to the inner part of the outer sheath layer (1) is arranged on one side of the supporting frame (3), a hollow sleeve (35) extending to the inner part of the outer sheath layer (1) is arranged on the other side of the supporting frame (3), a first sealing ring (36) is arranged at one end of the hollow sleeve (35), a connecting terminal (39) is arranged in the supporting frame (3), and a connecting conductor (38) connected with the hollow sleeve (35) is arranged in the connecting terminal (39).
  6. 6. The high-flame-retardant and temperature-resistant modified polyolefin low-voltage cable according to claim 5, wherein second positioning bolts (31) distributed at equal intervals are connected to the bottom of the supporting frame (3) in a threaded mode, a top disassembling positioning cover (33) is installed at the top of the supporting frame (3), third positioning bolts (34) extending to the inner wall of the supporting frame (3) are connected to the top of the top disassembling positioning cover (33) in a threaded mode, and an inner cavity (32) mounted by being matched with the connecting conductor (38) is formed in the supporting frame (3).
  7. 7. A method for preparing a high-flame-retardant and temperature-resistant modified polyolefin low-voltage cable, which is used for implementing the high-flame-retardant and temperature-resistant modified polyolefin low-voltage cable according to any one of claims 1 to 6, and is characterized by comprising the following components in parts by weight: 100 parts of matrix resin 120-180 Parts of surface modified flame retardant 5-15 Parts of zinc borate; 5-10 parts of expandable graphite; 2-5 parts of organic silicon resin powder; 2-5 parts of antioxidant; 1-3 parts of cross-linking agent; 3-8 parts of phase solvent; 2-4 parts of lubricant; 2-50 parts of color master batch.
  8. 8. The method for preparing the high-flame-retardant and temperature-resistant modified polyolefin low-voltage cable according to claim 7, which is characterized by comprising the following specific preparation steps: S1, raw material pretreatment and mixing: placing superfine magnesium hydroxide or aluminum hydroxide with the particle size D50 of 1.0-2.5 mu m into a high-speed mixer, heating to 110-130 ℃, adding a silane coupling agent ethanol solution with the weight of 1.0-2.0% into the mixture in a spraying manner, mixing for 15-30 minutes, discharging and drying to obtain the surface modified flame retardant; According to weight portions, 100 portions of matrix resin, 120-180 portions of surface modified flame retardant, 5-15 portions of zinc borate, 5-10 portions of expandable graphite, 2-5 portions of organosilicon resin powder, 2-5 portions of antioxidant, 1-3 portions of cross-linking agent, 3-8 portions of compatilizer, 2-4 portions of lubricant and 2-50 portions of color master batch are sequentially added into a high-speed mixer and mixed for 10-15 minutes at 60-80 ℃ to obtain uniform premix; S2, melt blending and granulating: Feeding the premix into a homodromous parallel double-screw extruder for melt blending, extrusion, water cooling and granulating to obtain high-flame-retardance and temperature-resistant modified polyolefin composite particles; The technological parameters of the twin-screw extruder are that the temperature of the first area is 150-160 ℃, the temperature of the second area is 160-170 ℃, the temperature of the third area is 170-180 ℃, the temperature of the machine head is 175-185 ℃, and the rotating speed of the screw is 200-350 rpm; S3, cable extrusion molding: And (2) after drying the composite particles obtained in the step (S2), respectively extruding an insulating layer and a sheath layer: the insulation extrusion, namely preheating an oxygen-free copper or tin-plated copper stranded wire conductor to 50-70 ℃, extruding the composite material on the surface of the oxygen-free copper or tin-plated copper stranded wire conductor through an insulation extruder to form an insulation layer, and controlling the temperature of the insulation extruder to 160-185 ℃; Twisting a plurality of wire cores extruded with insulating layers according to a preset twisting pitch to obtain a cable core; Extruding the sheath, namely extruding the composite material outside the cable core through a sheath extruder to form a sheath layer, wherein the temperature of the sheath extruder is controlled to be 155-180 ℃; s4, crosslinking treatment: carrying out irradiation crosslinking treatment on the cable core obtained in the step S3, wherein an electron accelerator is adopted, and the irradiation dose is 8-15 Mrad; s5, cooling, rolling and detecting: and cooling and drying the crosslinked cable through a cooling water tank, then sequentially performing spark withstand voltage test and outer diameter measurement, and rolling after the cable is qualified to obtain the high-flame-retardant temperature-resistant modified polyolefin cable finished product.
  9. 9. The method for preparing a high-flame-retardant and temperature-resistant modified polyolefin low-voltage cable according to claim 8, wherein the matrix resin is one or a mixture of more of ethylene-vinyl acetate copolymer, polyethylene and polypropylene; The flame retardant is one or a mixture of superfine magnesium hydroxide or aluminum hydroxide, the particle size D50 is 1.0-2.5 mu m, and the surface of the flame retardant is modified by silane coupling agents such as KH-550 and KH-560; the lubricant is one or a mixture of more of zinc stearate or polyethylene wax.
  10. 10. The method for preparing the high-flame-retardant and temperature-resistant modified polyolefin low-voltage cable according to claim 8, wherein the cable is characterized in that the cable is made of the following structural materials: An external installation conductor (11) adopts oxygen-free copper or tinned copper stranded wires; The insulating inner layer (12) is formed by extrusion of the high-flame-retardance temperature-resistant modified polyolefin composite material, and the thickness meets the standard requirement; the sheath outer layer (1) is formed by extrusion using the same composite material as the insulating inner layer (12) or by appropriately adjusting the plasticizer content to increase flexibility.

Description

High-flame-retardance temperature-resistant modified polyolefin low-voltage cable and preparation method thereof Technical Field The invention relates to the technical field of cables, in particular to a high-flame-retardance temperature-resistant modified polyolefin low-voltage cable and a preparation method thereof. Background Polyolefins (e.g., polyethylene PE, polypropylene PP) are widely used as insulation and sheathing materials for low-voltage power cables due to their excellent electrical insulation properties, easy processability, and low cost. However, the common polyolefin materials have two inherent defects, which limit the application of the materials in severe or high-safety requirement occasions, namely 1) the materials are poor in flame retardance, low in Limiting Oxygen Index (LOI) (about 17%), inflammable when encountering fire and accompanied by molten drops, easy to accelerate flame propagation, 2) the materials are insufficient in long-term heat resistance, the long-term use temperature of the conventional Polyethylene (PE) is generally not more than 70 ℃, the crosslinked polyethylene (XLPE) can reach 90 ℃, and the materials are easy to thermally deform and deteriorate in high-temperature overload or high-environment temperature occasions. The Chinese patent publication No. CN 107936600B discloses an insulated cable and a preparation method thereof, wherein the insulated cable comprises the following components in parts by weight, 10-20 parts of cross-linking insulating material, 10-20 parts of cross-linking agent, 3-5 parts of color masterbatch, 2-5 parts of carbon black and 4-5 parts of diphenyl boron chloride. Also comprises 5-7 parts of titanium dioxide, 10-20 parts of sodium silicate, 10-20 parts of calcium hydroxide and 10-20 parts of tributyl citrate. The titanium dioxide, sodium silicate, calcium hydroxide and tributyl citrate are utilized to reinforce, prevent aging and fill the rubber. Under the irradiation of sunlight, the product is sun-proof, does not crack or change color, and has greatly improved stretching rate and acid and alkali resistance. In order to improve the performance, the prior art mainly adopts the following methods: The flame retardant is most commonly added, and a large amount (usually more than 60 weight percent) of inorganic flame retardants such as aluminum hydroxide, magnesium hydroxide and the like are added to realize halogen-free flame retardance. However, high loadings seriously impair the mechanical properties (embrittlement), the processing flowability and the electrical properties of the materials; And (3) performing crosslinking modification, namely forming a three-dimensional network structure through chemical or irradiation crosslinking, and improving the heat-resistant deformation temperature. However, crosslinking itself does not significantly raise the oxygen index of the material, and conventional crosslinked polyolefins still burn in flame; Novel flame retardant systems have been developed, such as the use of intumescent flame retardants, silicone flame retardants, and the like. But often has the problems of high cost, poor compatibility with a matrix, harsh requirements on a processing technology and the like; The preparation method is simple in compounding, and a plurality of known flame retardants and heat-resistant auxiliary agents are mixed. However, if the scientific component design and synergistic effect consideration is lacked, the material comprehensive performance is easy to be unbalanced, and the severe requirements of high flame retardance, high heat resistance, good mechanical and electrical properties cannot be met at the same time, so that the requirements of normal use cannot be met. Therefore, the invention needs to design a high-flame-retardant temperature-resistant modified polyolefin cable and a preparation method thereof to solve the problems. Disclosure of Invention The invention aims to provide a high-performance modified polyolefin cable material which realizes the synergistic optimization and balance of flame retardance, temperature resistance, mechanical property and processability through a refined formula design, and a low-voltage cable with excellent comprehensive performance is prepared according to the high-performance modified polyolefin cable material, which is an important and challenging technical subject in the field. In order to achieve the purpose, the invention provides the following technical scheme that the high-flame-retardant temperature-resistant modified polyolefin low-voltage cable comprises the following components: a plurality of external mounting conductors; An insulating inner layer covering the plurality of externally mounted conductors, and A sheath outer layer coated outside the insulating inner layer; wherein the sheath outer layer and the insulating inner layer are both made of high-flame-retardance temperature-resistant modified polyolefin composite materials. As a preferred embodim