Orevac 18217 Modified ethylene based copolymer Arkema OREVAC 18217 is a modified Ethylene based copolymer specially intended to be use as tie layer between PS and EVOH in sheet coextrusion. It can also adhere to PE, EVA and PA. Modified ethylene based copolymer. Used as tie layer between PS and EVOH in sheet coextrusion. Provides adhesion to PE, EVA and PA.