Action Spectrum of Light Fastness of Carthamin Dyed on Silk Fabric under the Irradiation of UV and Visible Light

Abstract

A light fastness characteristic of Carthamin dyed on silk fabric was examined. The monochromatic light at every 20nm over 260-700 nm was exposed to the samples using a large spectrograph. An action spectrum of Carthamin fading was measured under a constant irradiation energy. A strong fading peak was observed in the visible light range of 500-600 nm as well as in UVA range. The absorbance spectrum of the dyed sample surface coincided fairly well with the action spectrum. On the other hand, the sample was exposed to sunlight under the simultaneous measurement of UV-A and UV-B. The fading characteristics were well interpreted using the action spectrum.