Properties of barrier shrink bags made with EVOH and polyamide for fresh beef meat preservation

Abstract

The objective of this work was to compare the barrier and mechanical properties and shrinkability of coextruded films chlorine-free, with high barrier chlorine multilayer films traditionally used to preserve fresh beef. Four 9-layer barrier-shrink films containing PET, ethylene ionomers, polyamide PA66/6 modified with amorphous PA, 32 or 44 mol% EVOH and PE were produced in a commercial scale triple bubble co-extrusion line. Seal strength, puncture resistance, oxygen and water vapor permeability and film shrink were measured for the four films and compared to the EVA/PVDC/PE film properties. The results obtained under controlled laboratory conditions show that films made with one layer of EVOH 32 mol% of ethylene encapsulated between two layers of PA66/6 modified with amorphous PA have gas barrier properties and puncture resistance better than a typical EVA/PVDC/PE, seal strength and shrinkability comparable to this film and therefore have potential to preserve fresh beef.

Keywords:
chlorine free; oxygen transmission rate; puncture resistance; shrink film; vaccum packaging