Inorganic modified high heat-resistant low-shrinkage low-smoke halogen-free flame retardant polyolefin cable material and preparation method thereof

Abstract

The invention relates to a cable material and in particular relates to an inorganic modified high heat-resistant low-shrinkage low-smoke halogen-free flame retardant polyolefin cable material and a preparation method thereof. The formula of the inorganic modified high heat-resistant low-shrinkage low-smoke halogen-free flame retardant polyolefin cable material comprises 100 parts of matrix resin, 120-160 parts of fire retardant, 10-30 parts of inorganic imvite, 1-4 parts of lubricant and 1-3 parts of antioxidant; the preparation method of the cable material comprises the steps of firstly, stirring the raw materials in a high-speed mixer evenly, secondly, banburying in a temperature interval from 110 to 130 DEG C by use of a Banbury mixer, and then feeding by use of a twin-screw feeder, extruding by use of double screws, molding by use of a single screw, hot cutting and pelleting by use of a grinding surface, conveying by use of a cyclone separator, sieving by use of a vibrating sieve and then packaging to obtain the finished inorganic modified high heat-resistant low-shrinkage low-smoke halogen-free flame retardant polyolefin cable material. Compared with a common low-smoke halogen-free flame retardant polyolefin cable material, the thermal aging resistance of the inorganic modified high heat-resistant low-shrinkage low-smoke halogen-free flame retardant polyolefin cable material is improved and the shrinkage performance of the cable material is greatly improved, and therefore, the problem of easy shrinkage of the low-smoke halogen-free polyolefin cable materials at high temperatures is solved.

Description

technical field [0001] The invention relates to a cable material, in particular to an inorganic modified high-heat-resistant, low-shrinkage, low-smoke, halogen-free, flame-retardant polyolefin cable material and a preparation method thereof. Background technique [0002] Most of the traditional low-smoke halogen-free flame-retardant polyolefin cable materials use LLDPE (linear low-density polyethylene) and EVA (ethylene-vinyl acetate copolymer) as the main resin base material, and graft PE (polyethylene graft) As a compatibilizer. Add a certain amount of aluminum hydroxide to make a low-smoke, halogen-free, flame-retardant polyolefin cable compound. However, it is difficult for this type of cable material to pass the thermal shrinkage test of less than 2% heat shrinkage required in electric cables or optical cables, and the heat resistance cannot meet the requirements, which limits the application of this type of traditional cable material. Affected by vinyl acetate monomer...

AI Technical Summary

Problems solved by technology

However, it is difficult for this type of cable material to pass the heat shrinkage test of less than 2% heat shrinkage required in cables or optical cables, and the heat resistance cannot meet the requirements, which limits the application of this type of traditional cable material

Affected by vinyl acetate monomer, the crystallinity of EVA is relatively low, and it has a good ability to accommodate powder, but the destruction of the crystal region by the inorganic flame retardant makes the temperature resistance of the material a little worse, although the traditional The heat resistance of LLDPE will be better, and the addition of LLDPE will improve the heat resistance performance, but because LLDPE shrinks greatly after being heated, the final product will shrink greatly at a certain temperature, which cannot meet the requirement of less than 2% heat shrinkage. Generally above 5%

Although the addition of inorganic flame retardant aluminum hydroxide will have a good effect on improving heat shrinkage, the effect is limited, and excessive addition of aluminum hydroxide will affect the physical and mechanical properties of the material

Therefore, it is difficult to find this balance point in the formulation system of traditional low-smoke halogen-free flame-retardant polyolefin cable materials, and it cannot meet the heat resistance and shrinkage tests of materials.