Surface Characterization of Cashmere Fabrics Using Optical and Transient Thermal Properties

Fine hairs on a cashmere fabric (i.e., its hairiness) generate its softness, warmth, and unique luster. To make cashmere more popular, we require value-adding elements and quality specification to develop new clothing products. In this study, a surface characterization method was examined to specify the effect of hairs on the softness, luster, and warmth of cashmere fabrics. The luster was measured using a goniospectrophotometer as the fabric was rotated. A high CIELAB L* was found for rotation angles θω around 90°, corresponding to an aligned fiber surface, but not for random fiber assemblies. The shape of the plot of L* versus θω was affected by the degree of hairiness and its direction. By measuring the surface roughness (SMD) with a surface tester, a difference in light reflection between the warp and weft directions of the fabric was observed according to the hairiness direction. Fabric surfaces with smaller values of SMD showed larger values of L*. These surface hairs and hairiness were also observed clearly as differences in the surface friction. For the transient heat flux (qmax) related to the warmth perception, hairier samples showed lower values than did less hairy samples.