Flame-retardant material used for cable sheath and preparation method thereof

Abstract

The invention provides a flame-retardant material used for a cable sheath and a preparation method thereof. The flame-retardant material used for the cable sheath is prepared from the following raw materials in parts by weight: 5-10 parts of metallocene polyethylene, 20-30 parts of an ethylene-vinyl acetate copolymer, 60-70 parts of polyethylene resin, 6-12 parts of a plasticizer, 10-20 parts of a composite flame retardant, 3-6 parts of organic silicone, 1-3 parts of an antioxidant and 2-6 parts of a lubricating agent, wherein the composite flame retardant is prepared from magnesium salt, nano silicon carbide and carbon nanotubes. The preparation method comprises the following steps: putting the raw materials into an internal mixer, heating to 115-135 DEG C, lifting the internal mixer to a top peg, reversing materials, after the materials are reversed, continuously mixing until temperature in the internal mixer reaches 145-155 DEG C, stopping heating, then continuously mixing for 2-5 minutes, then extruding by virtue of a single screw extruder, and pelletizing, so that the flame-retardant material is obtained. The flame-retardant material provided by the invention has good flame retardant effect and has the advantages of high oxygen index and strong self-extinguishing property while mechanical properties of the cable sheath are met.

Description

technical field [0001] The invention belongs to the technical field of flame retardant materials, and in particular relates to a flame retardant material for a cable sheath and a preparation method thereof. Background technique [0002] Plastic sheath materials need to be extruded on the outer layer of the cable. Usually, the sheath material of high-voltage power cables is made of black polyethylene material, and the outer surface is coated with conductive graphite or conductive polyethylene to prevent high-voltage induced voltage breakdown and reduce surface induced voltage. However, with the underground laying of urban high-voltage power grid lines, cables are required to have low-smoke, halogen-free and flame-retardant functions, and their sheath materials must be low-smoke, halogen-free, and flame-retardant black polyethylene materials. The flame retardant sheath material usually uses a large amount of inorganic aluminum hydroxide and magnesium hydroxide flame retardant ...

AI Technical Summary

Problems solved by technology

However, due to the low mechanical strength and hardness of the ethylene vinyl acetate copolymer material, the material has low mechanical strength and poor wear resistance, resulting in damage to the cable surface sheath during the installation and laying of the cable, especially for large cross-section cables. Once the cable sheath is broken, it may cause the instability of the power grid system, and the cable body will be subjected to various damages, which cannot effectively protect the effective operation of the cable; moreover, the existing low-smoke, halogen-free and flame-retardant sheath materials have poor adhesion, resulting in The conductive graphite layer or conductive polyethylene layer on the surface will fall off, so that the partial discharge current of the cable cannot be effectively released, affecting the effective use of high-voltage cables

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