Morphological, thermal and mechanical properties of polyamide and ethylene vinyl alcohol multilayer flexible packaging after high-pressure processing

Publication date: July 2020Source: Journal of Food Engineering, Volume 276Author(s): Luís Marangoni Júnior, Léa Mariza de Oliveira, Paula Fernanda Janetti Bócoli, Marcelo Cristianini, Marisa Padula, Carlos Alberto Rodrigues AnjosAbstractThe effect of high-pressure processing on the morphological surface, thermal and mechanical properties of three PA and EVOH based multilayer flexible packaging materials were evaluated. LDPE/PA/LDPE, LDPE/EVOH/LDPE and PET/LDPE/PA/EVOH/PA/LDPE packaging samples were processed under three different conditions (600 MPa/25 °C/10 min, 600 MPa/90 °C/10 min and 0.1 MPa/90 °C/10 min) and an unprocessed sample was used as control. The LDPE/PA/LDPE and LDPE/EVOH/LDPE samples showed good thermal stability and no surface defects after processing, because of the greater thickness of the external material, the film withstood the compression and decompression of the processing, consequently resulting in the protection of the other layers. The PET/LDPE/PA/EVOH/PA/LDPE sample showed a significant increase in the Tm of PET, LDPE and PA after processing at 600 MPa/90 °C/10 min. Regarding the mechanical properties, reductions in the tensile strength of the PET/LDPE/PA/EVOH/PA/LDPE sample were observed after processing at 600 MPa/90 °C/10 min. In addition, a significant reduction in heat seal strength was observed in the three materials after processing at 600 MPa, but these values are accepted in practice. Therefore, in terms of morphological...
Source: Journal of Food Engineering - Category: Food Science Source Type: research