The deposition of solid particles on cotton cloth in aqueous suspension to which is added watersoluble polymer was investigated. Solutions of sodium polyphosphate, polyethylene oxide, sodium polyacrylate, polyacrylamide, partially hydrolyzed polyacrylamide, and Tororo-aoi mucilage were prepared, and the preventing action to the deposition of ferric oxide or carbon black onto cotton fabrics was tested with Launder-Ometer. The effects are estimated by means of photoelectric colorimetry and the

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... lectivity of the surface of the soiled fabrics. The results obtained are as follows Tororo-aoi mucilage which is a fiber-dispersion agent in Japanese peper making by traditional process shows an excellent effects preventing the deposition of either ferric oxide or carbon black. The heteropolar polymers so far examined, with the exception of polyphosphate, are more effective for preventing the soil deposition than homopolar polymers. Sodium polyphosphate in concentrated solution appears rather to promote the deposition : the fact may be due to the formation of a complex compound. All polymers so far tested appear to be more effective to ferric oxide than to carbon black. It is considered that the soil deposition is facilitated by the flocculating action of water-soluble polymers and retarded by the dispersing action of the polymers. From these data, a mechanism of soil redeposition in textile cleaning operation is discussed.