Nano-modified low-shrinkage low-smoke halogen-free and flame-retardant polyolefin cable material and preparation thereof

Abstract

The invention relates to a cable material, and in particular relates to a nano-modified low-shrinkage low-smoke halogen-free and flame-retardant polyolefin cable material and a preparation method thereof. The polyolefin cable material comprises the following components: EVA (Ethylene Vinyl-acetate Copolymer), MLLDPE (Linear Low-Density Polyethylene), an interfacial compatibilizer, aluminum hydroxide, nanometer strong micropowder, an antioxidant and a lubricant. The preparation method comprises the following steps of: evenly stirring the EVA and the MLLDPE as basic materials, the interfacial compatibilizer, the aluminum hydroxide, the nanometer strong micropowder, the antioxidant and the lubricant in a high-speed mixer; performing banburying in a banbury mixer at the temperature between 120 and 150 DEG C; extruding by using double screw rods; granulating by grinding and hot-cutting; conveying materials by using a cyclone separator; and screening by using a vibrating screen and packaging, thereby obtaining the finished nano-modified low-shrinkage low-smoke halogen-free and flame-retardant polyolefin cable material product. Compared with the common low-smoke halogen-free and flame-retardant polyolefin cable material, the polyolefin cable material provided by the invention has the effects that the thermal aging resistance is enhanced; the shrinkage performance of the product is improved greatly; and the problem that the low-smoke halogen-free polyolefin cable material is easy to shrink at the high temperature is solved.

Description

technical field [0001] The invention relates to a cable material, in particular to a nano-modified low-shrinkage, low-smoke, halogen-free flame-retardant polyolefin cable material and its preparation. 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 PE graft (polyethylene graft) As a compatibilizer, a certain amount of aluminum hydroxide is added to obtain a low-smoke, halogen-free, flame-retardant polyolefin cable compound. However, it is difficult for this type of cable material to pass the heat shrinkage test required in electric cables or optical cables with a thermal shrinkage of less than 2%, 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 accomm...

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Problems solved by technology

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art, provide a nano-modified low-shrinkage, low-smoke, halogen-free flame-retardant polyolefin cable material and its preparation method, and solve the conflicting problems caused by the addition of aluminum hydroxide. Technical problems, and compared with ordinary low-smoke halogen-free polyolefin cable materials, the obtained cable material greatly improves the thermal shrinkage performance of the material and improves the aging resistance of the product. The material can shrink less than 2 % heat shrinkage test; and the original traditional material under the air oven aging test at 110 ℃ × 168h, the change rate of tensile strength and elongation at break of the sample is ≤ ± 30%, increased to 110 ℃ × 168h Under the air oven aging test, the change rate of tensile strength and elongation at break of the sample is ≤ ± 15%

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