Abstract
The transmission of ultraviolet (UV) rays through clothes was determined by varying physical factors. The authors have concerned on the influence on the density, i.e., the number of yarns per unit area (yarns/cm2), of clothes and number of twists of yarns. Results obtained are as follows:
1) The higher density of clothes and the lower number of twists of yarn, the lower UV transmission through clothes.
2) The higher density of clothes and the lower number of twists of yarn, the higher coefficients of absorption and scattering. It was found that the increase in the coefficient of scattering is more effective than that in the coefficient of absorption.
3) The apparent coefficient of absorption and scattering per yarn, determined from density of cloth, is decreased by increasing density of clothes.
4) Assuming that yarns in the thickness direction will shift to warp-or weft-direction by pressing the cloth, the number of yarns per unit area has been calculated. The coefficients of absorption and scattering of single yarn, which were calculated from the density thus calculated, are equal for samples of different thickness. These results enable us to perform a comparison of the transmission of ultra violet rays among various samples with different thickness.
