We tested the detergency of the cleaning agents (i. e., soap solution, sodium dodecyl sulfonate, and linear alkylbenzen sulfonate which were mixed with Na_5P_3O_) in the casces of cotton, polyester fabric and polypropylene fabric which had been soiled by ferric oxide. The following are the results of the test which we got by comparing the rate of detergency efficiency calculated from the rate of surface reflectivity, with the rate of desorption calculated from the amount of Fe_2O_3 on the soiled fabrics. (1) The most marked detergency was recognized in the case of the po1yester fabric when it was cleaned by any detergent agent mixed with Na_5P_3O_. (2) Of the three surface active agents, SDS, and LAS showed the most marked effect on the soiled fabrics when they were mixed with Na_5P_3O_ respectively. (3) We examined the detergency of three detergents (soap solution, LAS, SDS ) taking into account their desorption also. And as the result of the examination it was found out that these different detergents had the different effects upon the soiled fabrics but the same trend of the efficiency of cleaning was recognized on the graph among them
