Experimental study of back-scattering spectrum of textile structures
Résumé
The back-scattered light by textile surfaces mainly depends on their surface state, which is often periodic and directional. The analysis of the reflectance spectra in back-scattering conditions of two hypes of structures (yarn, plain and twill weaves) shows the influence of the orientation of these surfaces as well as the back-scattered angle. In fact, the declination of the yarn orientation in relation to the incidence plane involves an increase of the reflectance factor to reach a maximum value when the Yarns are perpendicular to this plane. For woven fabrics, the backscattering of surface according to a given orientation primarily depends on its geometrical characteristic in this direction and consequently the used yarn densities. The computation of the ratio of mean quadratic surface roughness h to correlation length I for various used orientations shows the close link between this parameter and the evolution of back-scattering. The effect of the variation of backscattered angle on the back-scattered light varies with the value of h/l. The comparison between these experimental results and a theoretical study based on Gaussian and isotropic surfaces shows a satisfactory correlation between these two elements with the presence of some cases of discrepancy due to the different natures of the two types of surfaces. (c) 2006 Wiley Periodicals, Inc.