Exploring the Effects of Ultrasound Processing on Food Packaging Laminated With Aluminum Foil

Abstract

This study investigates the effects of ultrasound (US) processing on laminated plastic packaging containing aluminum foil for food contact applications. Two multilayer structures, PET/Al/PE and PET/Al/PP, were exposed to US at 25 kHz and 8.75 W/L for up to 40 min at 25°C and 60°C, using a 3% acetic acid as a food simulant. The structural, mechanical, thermal, barrier, and migration properties of the packaging were evaluated. Results indicate that US exposure for up to 30 min did not alter chemical composition, thermal stability, seal strength, nor barrier properties. A slight rise in elongation at break in the machine direction of the PET/Al/PP film was noted when processed at 60°C with ultrasound, relative to both the untreated samples and those treated at 25°C. No significant overall, aluminum, or antimony migration was detected. These findings demonstrate that aluminum-laminated packaging can be safely used in US food processing applications, provided that exposure time does not exceed the time to prevent structural degradation.