A LABORATORY COMPARISON OF THE DETERGENT EFFICIENCIES OF LAUNDRY SOAP BUILDERS

The detergent efficiencies of four common laundry soap builders have been measured and compared on a laboratory scale. Their order of decreasing efficiency when both concentration and actual washing efficiency are considered is caustic soda, soda ash, sodium metasilicate and trisodium phosphate. When actual washing efficiency alone is considered the order is sodium metasilicate, caustic soda, trisodium phosphate, and soda ash. In all experiments the soap concentration was 0.1%.pH values of the built soaps are given over a wide range of concentration. All soap builders do not exert their optimum detergent effect at the same pH value.Two of the alkalies, namely caustic soda and sodium metasilicate, increased the. lathering power of the soap notably.