Channel defect detection in food packages using integrated backscatter ultrasound imaging

Area of Science:

• Materials Science
• Non-destructive Testing
• Food Packaging Technology

Background:

• Hermetically-sealed flexible food packages are crucial for extending the shelf stability of thermally processed foods.
• Effective seal integrity testing is essential to ensure food safety and quality.
• Conventional methods struggle to detect sub-wavelength defects in food package seals.

Purpose of the Study:

• To estimate the detection limits of pulse-echo ultrasonic imaging for simulated defects in food package seals.
• To develop and evaluate a novel imaging technique with sub-wavelength imaging capabilities for detecting small defects.
• To assess the effectiveness of the backscattered amplitude integral (BAI) imaging technique.

Main Methods:

• Generation of laboratory-scale defects (9-325 micrometers) in heat-sealed plastic films simulating food package seals.
• Utilizing pulse-echo ultrasonic imaging techniques in the 13-17 MHz frequency range.
• Comparison of conventional B-mode imaging with the newly developed BAI-mode imaging technique.

Main Results:

• Conventional B-mode imaging was inadequate for sub-wavelength defect detection.
• The developed BAI-mode imaging technique demonstrated sub-wavelength imaging capabilities.
• BAI-mode imaging successfully detected a 10-micrometer diameter channel defect at 13.1 MHz.

Conclusions:

• The backscattered amplitude integral (BAI) imaging technique offers superior sub-wavelength detection capabilities for food package seal defects compared to conventional methods.
• BAI-mode imaging is a promising advancement for non-destructive seal integrity testing in the food industry.
• This technology can enhance the reliability and shelf-life of thermally processed foods in flexible packaging.