Polarimetric measurements of fabric surfaces

Abstract

We describe an optoelectronic setup designed to evaluate the surface parameters of fabrics that influence their tactile feel. The developed texturometer uses the periodic structure of a textile material and its ability to reflect light to evaluate its surface properties through its polarimetric properties. The device scans the surface with a laser line and performs a temporal Fourier analysis of the reflected light, which allows us to consider the periodical structure of the material's surface. Instead of using the overall reflected energy, the analysis is performed on the degree of polarization of light. Results obtained with this new texturometer are compared to those obtained with a nonpolarimetric device that uses overall reflected energy. Emerized and nonemerized twill fabrics are tested, as well as spun-bonded nonwovens. We show that discrimination between samples is enhanced with this polarimetric texturometer. For emerized fabrics, the results exhibit a decrease in depolarization as emerizing intensity increases. For nonwovens, a complementary study in polarimetric imaging has been performed to better understand the phenomena. Nonwoven thermobonded points exhibit lower depolarization of the lightwave than the rest of the structure. Moreover, their depolarization differentiates the tested nonwovens.