Ultrasonic Imaging of Micro‐Leaks and Seal Contamination in Flexible Food Packages by the Pulse‐Echo Technique

Abstract

ABSTRACT Reliable inspection of flexible food packages for micro‐leaks and product contamination in the seal area is needed to prevent spoilage and safety hazard. Nondestructive testing by the ultrasonic imaging method, Backscattered Amplitude Integral (BAI), was evaluated for use in defect detection. Channel defects (6–15 μm in diameter) and simulated food strands (20–60 μm dia) perpendicular to the sealing direction were fabricated within the seal region of both all‐plastic and foil‐containing retortable pouches. Results showed that 17.3‐MHz pulse‐echo BAI‐imaging detected channel defects (9.5–15 μm) and all strand‐inclusion defects in both types of package materials.