ARS | Publication request: Airborne ultrasonic inspection of hides and leather

Submitted to: American Leather Chemists Association Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2011
Publication Date: N/A

Technical Abstract: Currently, hides and leather are visually inspected and ranked for quality, sale price and usable area. Visual inspection is not always reliable for detecting defects, particularly when they are hidden inside the material. This manual assessment is non-uniform among operators, and often leads to disputes over fair price. Development of a nondestructive method to accurately evaluate the quality of hides and leather is needed. We have investigated airborne ultrasonic (AU) testing using non-contact sensors for the nondestructive evaluation of hides and leather. The AU test system is an ideal inspection method for large hides or leather and is designed for automated and moving process applications. The AU sensors are mounted on a computer-controlled X-Y scanner that allows the sensor array to be moved over the entire surface of the hide. The AU testing involves pulsing ultrasonic signals and measuring the amplitude of those signals that traveled through the material. This research examines the ability of AU techniques to reveal defects in hides and leather that are difficult to be found during visual inspection. The key for success in AU testing is to use AU sensors with low resonant frequencies, which leads an effective penetration of waves through the leather or hides. Observation showed that test areas with different amplitudes in the C-scans obtained from AU testing is an indication of the presence of defects or some other physical discontinuity that could affect the hides or leather quality. Using the AU C-scan images could advance the industry in how it assesses and grades raw hides, wet blue, wet white and finished leather.