Abstract
In case of evaluating the bleaching agents under practical conditions, bleaching effect is evaluated by the difference of surface reflectance, which ranges about 10-15% from grey (unbleached) cloth to bleached one.
To improve the precision of the measurement under the circumstance of such a slight difference in refrectance, the authors have been developed a method by applying a certain dye, in solution or on the fibrous substrates, to the bleaching solution, which dye reveals a reasonable correspondence to the bleaching effect under the testing conditions.
Acid Orange R (C. I. 15575) has been proved to be the most suitable among 20 dyes tested.
