Low-smoke, halogen-free and highly-flame-retardant oxygen barrier layer cable material for medium-voltage cables

Abstract

The invention discloses a low-smoke, halogen-free and highly-flame-retardant oxygen barrier layer cable material for medium-voltage cables. The cable material comprises, by mass, 20-24 parts of ethylene-vinyl acetate resin, 0.4 part of a coupling agent, 20 parts of magnesium hydroxide, 48-50 parts of aluminum hydroxide, 1.5-2 parts of silicone rubber, 1-2 parts of carbon black, 5-6 parts of a graft copolymer and 0.2-0.3 part of an antioxidant. The low-smoke halogen-free high flame-retardant oxygen barrier layer cable material uses the ethylene-vinyl acetate resin with a vinyl acetate content reaching up to 40%, so the coverage on a flame-retardant powder is improved, and the mechanical properties of the material are improved, thereby large-batch processing in factories can be easily realized; the selected ethylene-vinyl acetate resin with the high vinyl acetate content and the flame-retardant powder are blended and copolymerized to improve the flame retardant performance of the layer;and the oxygen index of the halogen-free oxygen barrier layer material is increased to 58%, the category A beam combustion of the medium-voltage cables is completely solved, the smoke density of the cables during combustion is reduced, and the light transmittance is significantly increased to 62%.

Description

technical field [0001] The invention relates to the technical field of cable processing, in particular to a low-smoke, halogen-free, highly flame-retardant, oxygen-barrier layer cable material for medium-voltage cables. Background technique [0002] Halogen-free flame retardant and oxygen barrier materials for single-core medium-voltage cables used in subways. With the rapid economic development in recent years, the ever-changing urban construction is inseparable from the laying of cables and cables. People-intensive places such as subways, high-speed rails, shopping malls, etc. need more Environmentally friendly wires and cables such as polyolefin-based low-smoke halogen-free flame-retardant cables. However, the halogen-free low-smoke flame-retardant single core used in subways generally cannot meet the GB / T19666-2005A type of beam combustion test, and there are defects such as high smoke density and low light transmittance. If the above defects need to be compensated, the ...

AI Technical Summary

Problems solved by technology

However, the halogen-free low-smoke flame-retardant single core used in subways generally cannot meet the GB / T19666-2005A type of beam combustion test, and there are defects such as high smoke density and low light transmittance. If the above defects need to be compensated, the material flame retardant is required. The weight increases, but the excessive flame retardant will lead to the decline of the mechanical properties of the material, the machine current is overloaded when the cable is extruded, the extrusion temperature increases with the friction heating, and the material is degraded to form pores and melt rupture

[0003] However, the flame retardant effect of the existing medium-voltage cable (model WDZAYJY63) is not good, and the oxygen index is not high. There are two deficiencies in the following aspects: First, if the oxygen index is increased The amount of flame retardant is not easy to produce and process, and the extrusion resistance is large; secondly, increasing the amount of flame retardant in the production process will increase the friction temperature of the extruder screw, resulting in material degradation and the formation of pinholes. The combustion effect is not good and the mechanical properties of the material are reduced