Full definition
EVA Rubber, or Ethylene-Vinyl Acetate, is a copolymer that is classified as a thermoplastic elastomer rather than a traditional vulcanized rubber. This unique classification allows EVA to exhibit properties that are highly valued in various industrial applications. Its lightweight and closed-cell foam characteristics enable it to provide excellent cushioning and flexibility, particularly at low temperatures. The material's composition typically contains vinyl acetate (VA) in the range of 18-40%, with higher VA content leading to a softer, more rubber-like feel. This makes EVA suitable for applications where comfort and flexibility are paramount, such as in athletic footwear and protective packaging.
When expanded into foam, EVA has a density ranging from 30 to 200 kg/m³, making it not only lightweight but also an effective shock absorber. Its closed-cell structure contributes to waterproof capabilities and good thermal insulation, which is crucial in environments requiring both moisture resistance and temperature regulation. The hardness of EVA foam generally falls between 25 to 50 Shore C, while solid forms can reach 40 to 90 Shore A. This versatility in hardness allows for a wide range of applications, from soft cushioning in footwear to sturdier components in various industrial uses.
EVA's operational temperature range is from -40 to +60°C, although its performance diminishes at higher temperatures. It is commonly processed through methods such as injection molding, compression foaming, and extrusion, which facilitate the creation of diverse product forms. Despite its advantages, EVA does have limitations, including poor resistance to oils and UV degradation without appropriate stabilizers. Consequently, while EVA is an excellent choice for many applications, it should not be used as a substitute for traditional rubber in high-demand sealing or dynamic applications where resilience and durability are critical.