ULTRASONIC AIR-COUPLED INSPECTION OF TEXTILE MATERIALS USING FERROELECTRET-BASED PHASED ARRAYS.

Most common defects in textile manufacturing processes include weaving errors (such as missing threads), oil spots and material inhomogeneities. In this work, we demonstrate the feasibility of using ferroelectret-based transducers for the inspection of woven material. A linear array of 32 elements was built for this purpose following an easy fabrication procedure recently proposed. Electronic focusing at the textile sample position allowed us to detect weaving errors and oil spots of up to ∼1 mm of width in through transmission mode, at normal incidence and with a good signal-to-noise ratio. [ABSTRACT FROM AUTHOR]