Ethylene Vinyl Alcohol, commonly abbreviated EVOH, is a formal copolymer of ethylene and vinyl alcohol. Because the latter monomer mainly exists as its tautomer acetaldehyde, the copolymer is prepared by polymerization of ethylene and vinyl acetate to give the ethylene vinyl acetate (EVA) copolymer followed by hydrolysis. The plastic resin is commonly used in food applications, and it has lately found application in plastic gasoline tanks for automobiles. Its primary purpose is to provide barrier properties, primarily as an oxygen barrier for improved food packaging shelf life and as a hydrocarbon barrier for fuel tanks. EVOH is typically coextruded or laminated as a thin layer between cardboard, foil, or other plastics. EVOH copolymer is defined by the mole % ethylene content: lower ethylene content grades have higher barrier properties; higher ethylene content grades have lower temperatures for extrusion.
The company EVAL Europe started up in 2004 in Zwijndrecht (Belgium) the biggest production facility of the world with a capacity of 24.000 ton/a.[1]
Nippon Gohsei has three (3) production sites in Japan, US and Europe. In 2004, Nippon Gohsei started production at its Hull, UK, site having the world's largest single line capacity. [2] It is sold under the trade name SoarnoL.
EVOH is used in liquid embolic system in inverventional radiology, e.g. in Onyx. [3] Dissolved in dimethyl-sulfoxide (DMSO) and mixed with a radiopaque substance Ethylene Vinyl Alcohol Copolymer is used to embolise blood vessels.