Since many years ago, manufacturers have tested the quality of container closures, and their perceived value has constantly grown. Companies that once relied on probabilistic techniques like the blue dye test are now aiming to use a more reliable and predictable procedure for integrity testing of various package formats. The pharmaceutical industry is getting ready to adapt to the deterministic testing world in order to enhance quality, increase efficiency, and comply with changing regulatory standards.
Overview of Airborne Ultrasound Technology
Airborne ultrasound technology is a seal quality inspection technique. It is an ASTM test method F3004, the FDA approved standard for seal quality testing. Such tests are mainly performed to provide enhanced seal quality testing of pouches, flexible packages and tray seals. Airborne ultrasound technology ensures in-depth seal quality analysis and applies to multiple packaging materials including Tyvek, paper, foil, film, aluminum, plastic and poly.
In this technique, sound waves are reflected when ultrasound waves pass through the package seal. Signal strength is reduced or eliminated in the presence of leakage / fault. Such deviations are closely monitored to detect leakage. The inability to detect non-leak defects is a common challenge faced by most leak test methods. However, with Airborne ultrasound technology, users can identify various types of seal defects; visible and invisible, leaky and non-leaky, process-related and random.
Seal-Scan and Seal-Sensor Technology
Seal-Scan and Seal-Sensor are the two variants of Airborne ultrasound technology that utilizes non-contact airborne ultrasonic testing technology. With advancements in the form of seal-scans and seal-sensors, Airborne ultrasound technology has proven to be the most effective method for non-destructive seal integrity testing in both offline laboratory testing for seal quality analysis and 100% inline testing on the production line.
Seal-Scan® is a non-destructive offline technology that is highly effective in inspecting and analyzing pouch seal defects. It is a deterministic, quantitative, high-resolution package integrity testing method for identifying defects and sealing integrity for consistency. What makes this technique unique is that it is a non-invasive technique and requires no sample preparation. Seal-Scan® provides advanced digital imaging software tools for process control, offering in-depth seal quality analysis. This technology is capable of producing opto-acoustic images and detailed statistical analysis using L-scan and C-scan modes. An L-scan is a single linear scan along the x-axis of the seal that provides a line graph of seal integrity and simulates an online inspection. A C-scan produces multiple scans (in the X and Y-axis of the seal area) that provide a high-resolution ultrasonic image of the seal structure.
Seal-Sensor™ is an Airborne ultrasonic technology (ABUS) that non-destructively inspects the final pouch seal 100% online. The seal sensor detects incomplete seals, partial or weak areas of the seal, and many other common defects in a seal that are visually acceptable, but have that affect product quality, value, and shelf life. A pass/fail result and quantitative, traceable data are produced in less than a second by a single linear scan (L-scan) of the pouch seal. The Seal-Sensor is a definitive, quantitative, rapid and reliable approach to inspecting pouch seals for defects.
Benefits of Airborne Ultrasound Technology
- Non-destructive, non-subjective, no sample preparation.
- Accurate and reliable results.
- Can accommodate a number of packaging formats and materials.
- Eliminates subjective manual inspection methods.
- Deterministic inspection method producing quantitative results.
- ASTM Test Method F3004 and FDA Standard for seal quality inspection.
Today, package integrity test solutions continue to evolve, driven by industry demands, regulatory requirements, and advancements in technology. The focus remains on improving sensitivity, accuracy, and efficiency to ensure the integrity and safety of packaged products.