Sinopec Successfully Produces EVA Semiconductive Shielding Material for the First Time

Recently, Yangzi Petrochemical successfully produced a new product, EVA (ethylene-vinyl acetate copolymer) semi-conductive shielding material UE1930TK, for the first time, becoming one of the few companies in China with the capability to produce this product.

On June 13, Yangzi Petrochemical successfully completed the trial production of a new type of cable material, UE2850TK, which is a high vinyl acetate content, low melt index EVA (ethylene-vinyl acetate copolymer). Testing has shown that all product indicators meet the standards. This trial production has enriched the EVA product structure and enhanced market competitiveness. This grade of product is mainly used in the field of halogen-free flame-retardant cables, where the market is currently dominated by imported materials. Compared with conventional grade EVA cable materials, this product has a further reduced melt index and excellent processing performance.

EVA (ethylene-vinyl acetate copolymer) semiconductive shielding material is a specialized material used in the cable industry, primarily serving as the shielding layer in medium and high voltage power cables. It is a key material for high voltage cables, used to ensure uniform electric field distribution and prevent partial discharge. EVA semiconductive shielding material features excellent impact resistance, stress crack resistance, flexibility, high elasticity, and chemical stability. It is recyclable and aligns with the green development trend of cables.

At present, high-end wires and cables, as supporting products for electric vehicle charging stations, ultra-high voltage power grids, and other fields, are experiencing rapid growth in demand.In the application of cable materials, EVA has diverse uses. In low-smoke halogen-free cable materials, due to the dense smoke and harmful gases produced by burning PVC cables, safety is questioned, and low-smoke halogen-free cable materials have developed rapidly. These materials use polyolefin materials (mainly EVA) as the base resin, with the addition of hydroxide flame retardants and others. EVA is widely used because it contains polar groups, with an addition ratio generally between 10% and 30%. However, its strength is low, so it is often blended with PE and other materials. Additionally, radiation crosslinking is suitable for crosslinking low-smoke halogen-free polyolefin materials, which can improve the cable’s temperature rating, requiring the addition of crosslinking auxiliaries and adjustment of the antioxidant system. In semiconductive shielding materials, EVA is chosen as the base resin because it can accommodate a large amount of conductive fillers and matches well with the insulation layer materials. Furthermore, EVA can also serve as a toughening or flexibility-enhancing auxiliary component, used to improve the performance of PVC, EPDM, HDPE, and other cable materials, and can be made into compatibilizers to enhance product elongation.