Influence of high-pressure processing on morphological, thermal and mechanical properties of retort and metallized flexible packaging

Abstract

The effect of high-pressure processing on the morphological, thermal and mechanical properties of flexible packages was evaluated. The packages were composed of PET/Al/PA/PP (sample A) and PET/printing/ metallization/PET/LDPE-coex (sample B), were processed under three different conditions (600 MPa/25ºC for 10 min, 600 MPa/90ºC for 10 min and 0.1 MPa/90ºC for 10 min), with an unprocessed sample being used as a control. Sample A showed visual and microscopic defects after processing at 600 MPa/90ºC in 20% of the processed packages, and the melting temperature of the PA layer was significantly lower (p < 0.05) after processing at 600 MPa/25ºC and 90ºC compared to control. In addition, high-pressure processing influenced the mechanical property results. For sample B, no changes were observed in thermal and morphological properties after varying process conditions. However, in the 90º C processes there was a reduction in elongation of the material, bond strength and heat sealing strength.