Abstract:

This paper studies the applicability and feasibility of using the test results of whiteness tester and UV-Vis spectrophotometer in combination with subjective visual assessment to characterize the light shielding properties of fabrics. The results showed that the value of whiteness R457 and the value of transparency Vt which were obtained by whiteness tester reflected the visual clarity of fabric in a certain extent. However, the dependence of visual clarity of dyed fabrics on the transparency value Vt was low as compared with the white fabrics. The transmission coefficients of monochromatic light within the scope of visible lights could be measured by UV-Vis spectrophotometer, and the average the transmission coefficients Tj is more suitable for characterization and evaluation of the light shading performance of fabrics, especially coloured fabrics. The relationship between the Tj and the visual clarity of fabrics is much closer than that of Vt and visual clarity. The smaller the average transmission coefficient Tj , the better the shading performance of fabric. The experiments also proved that the fabrics were visible when the Tj was larger than 40%, but when the Tj was smaller than 20%, the fabrics were invisible.