Study on light-induced discoloration rule of wheat straw on NaHSO3 bleached

The Light fastness is straw crafts surface nature and quality of one of the evaluation. Using spectrophotometer, study of wheat straw surface chromaticity index change for different time periods, in the UVA-340 fluorescent UV lamp 24 +48 × (2.5 +0.5) = 168h. The results showed that : (1) Radiation 156h sample and bleached sample(1% NaHSO₃) chromatic aberration ΔE* difference value is 4.64NBS, known by the "Color value of the human visual relationship", chromatic aberration is between 3.0-6.0 NBS, human perception is "perceived". (2) Chromaticity index change and irradiation time was nonlinear, with the extension of irradiation time, whiteness W difference weak, chromatic aberration ΔE*, lightness difference ΔL* showing different degrees of ups and downs of small amplitude shocks state.