Highly bi-axially oriented, heat-shrinkable, thermoplastic, multi-layer film and process for the manufacture thereof

Abstract

A bi-axially oriented, heat-shrinkable multi-layer film comprising a core layer (A) comprising an ethylene-vinyl alcohol copolymer (EVOH), a first outer layer (B) comprising an ethylene homo- or co-polymer and a second outer layer (C), which may be equal to or different from the first outer layer (B), comprising an ethylene homo- or co-polymer, characterized in that said film has been bi-axially oriented at an orientation ratio in the longitudinal direction higher than 4:1, preferably higher than 4.5:1, more preferably of at least 5:1 and at an orientation ratio in the cross-wise direction higher than 4:1, preferably higher than 4.5:1, more preferably of at least 5:1, is obtained by a process which comprises melt extrusion of the film polymers through a flat die and orientation of the obtained cast sheet simultaneously in the longitudinal and the transversal directions by a simultaneous tenter.

Dependencies are inferred from the claim text.