Abstract
Taking into account of an effect of optical density to enhance the cross-sectional views of fibrous materials, a new preparative technique was applied to detect the skin-core structure of Cupra and Tencel filaments. The same sample species were also examined to determine the characteristic concentration gradient of dye molecules along the fiber axis starting from the sliced section. Microphotospectroscopic observation of a Cupra and Tencel filaments shows that the diffusion rate is predominant factor at the initial stage of dyeing and then an equilibrium state is attained depending on the fine structure of fibrous materials.
