Halogen-free low-smoke ethylene-vinyl acetate inner sheath material for B1-level flame-retardant cable and preparation method

Abstract

The invention relates to a halogen-free low-smoke ethylene-vinyl acetate inner sheath material for a B1-level flame-retardant cable and a preparation method and belongs to the technical field of cables. The halogen-free low-smoke ethylene-vinyl acetate inner sheath material is prepared from the following ingredients in parts by weight: 40 to 60 parts of ethylene-vinyl acetate copolymer ingredientA, 40 to 60 parts of ethylene-vinyl acetate copolymer B, 250 to 300 parts of special silane modified magnesium hydroxide, 5 to 10 parts of a smoke suppressor, 3 to 5 parts of paraffin, 15 to 20 partsof a lubricant, 1 to 2 parts of an anti-sticking agent, 1 to 2 parts of an anti-ageing agent, 8 to 10 parts of a compound synergistic flame retardant, 3 to 5 parts of a cross-linking agent and 1 to 2parts of an accelerant, wherein the lubricant is one or several in DOTP, zinc stearate and a fluorine containing polymer. The inner sheath material disclosed by the invention has excellent propertiesof ultrahigh oxygen index, low heat release rate / total amount, low smoke production rate / total amount, low smoke toxicity, low corrosivity, incombustible dripping, waterproofness and the like. A prepared subway direct-current traction cable can meet fireproof requirements of B1-level flame retardance, d1-level combustion dripping / particles, t0-level smoke toxicity, a1-level corrosivity and the like in GB31247-2014.

Description

technical field [0001] The invention relates to a sheathing material and a preparation method thereof, in particular to a halogen-free low-smoke ethylene-vinyl acetate inner sheathing material for B1-level flame-retardant cables and a preparation method, and belongs to the technical field of cables. Background technique [0002] The subway has become the most indispensable mode of transportation for urban commuting. The ranking of urban subway mileage in my country is refreshed every year, focusing on the number of mileage and passenger flow. According to statistics, as of 2017, a total of 174 subway lines of 4,880km in 34 cities including Shanghai, Beijing, Guangzhou, and Shenzhen were in operation, and cities such as Changzhou, Xuzhou, and Nantong were under construction. By 2020, the number will reach 40. By then, my country's urban rail transit The total mileage will exceed 6,000 kilometers. The accelerated pace of transportation construction and the increase in the mile...

AI Technical Summary

Problems solved by technology

At present, the thermoplastic halogen-free low-smoke flame-retardant cable materials used in most DC traction cables of subways cannot meet the requirements of B1-level flame-retardant cables.

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