Cross-linked fire-resistant cable material with 125 degree radiation

Abstract

A cable material with Radiation-crosslinking flame retardant property at temperature of 125 Deg C. is made of 100 portion polyethylene resin, 50-150 portion EVA, 0.1-0.4 portion primary antioxidant, 0.05-0.1 secondary antioxidant, 0.2-0.4 portion lubricant, 5-8 portion anti-radiation base material, 5-8 portion crosslinking agent, 35-50 portion flame retardant and 0.2-0.5 portion smoke-suppressant. It is mixed by high speed mixer, and is plasticized by extruder.

Description

technical field [0001] The invention relates to plastics used for electric wires and cables, belonging to polymer materials. Background technique [0002] At present, the insulation material of wire and cable has changed from polyvinyl chloride to polyolefin insulation material, because polyolefin has the characteristics of excellent electrical insulation performance and good mechanical and physical properties. And polyolefin insulation has developed towards cross-linking. At present, there are three main methods of cable cross-linking technology, namely, the warm water cross-linking method of silane grafting, the peroxide chemical cross-linking method and the high-energy electron beam irradiation cross-linking method. Through cross-linking, the wire and cable polymer is transformed from a linear structure to a three-dimensional network structure, so as to achieve the purpose of material modification. At present, chemical cross-linking and silane bonding are commonly used....

AI Technical Summary

Problems solved by technology

At present, chemical cross-linking and silane bonding are commonly used. Chemical cross-linking requires high equipment, large investment, and low production efficiency during extrusion. It is only suitable for medium and high voltage insulated power cables; silane warm water cross-linking requires high equipment requirements. It is not high, the processing technology is simple, but the degree of cross-linking is not easy to increase; while irradiation cross-linking is carried out at normal temperature and pressure, without the need for cross-linking media, it not only saves energy, but also has high production efficiency and a wide range of applicable materials. The polymer temperature rise caused by energy usually does not exceed 70 °C, and the halogen-free polyolefin insulation layer or sheath with flame retardants such as hydrated aluminum oxide or magnesium hydroxide will not decompose due to high temperature during the crosslinking process, so it is particularly suitable for Processing flame retardant cable

At present, hydrated alumina or magnesium hydroxide is generally used as flame retardant in China, but in order to achieve sufficient flame retardant effect, sufficient inorganic flame retardant must be mixed in, generally 50%-60%, such a large amount of inorganic flame retardant mixed , will inevitably lead to a decrease in the physical properties of the filling material, affect the processing performance, and also reduce the electrical resistance of the material and increase the dielectric loss, which limits the application in high-voltage (above 6kV) cables and most communication cables. It is easy to study some processes , cable materials adapted to the use of radiation methods have become a challenge for the cable material industry