Studies of Detergency

The difficulty or ease of soil removal from soiled fabrics has been studied. Cotton, nylon, polyester, and wool fabrics were soiled with five oily soils and were laundered with eight different detergents under various washing conditions. Variable bath components were surfactant types, water hardnesses, detergent concentrations, and bath temperatures. The contribution of such fabrics, soil, detergents, and bath conditions were estimated by the analysis of variance. The contributions of these factors increase in the following order: (a) (Fabric) > (Fabric) X (Soil) > (Soil) > (Others) when water hardness is chosen as a variable; (b) (Fabric) > (Concentration) > (Fabric) X (Soil) > (Soil) > (Others) when detergent concentration is chosen as a variable; (c) (Fabric) > (Fabric) X (Soil) > (Others) when wash temp erature is chosen as a variable. For each condition, the detergent contribution of fabric is the largest, while that of mutual interaction between fabric and soil is also very large. , The analysis of variance suggested that the difficulty or ease of soil removal is determined mainly by the combination fabric and soil; the type of fabric or the mutual interaction between fabric and soil is also an important factor in deter mining the degree of soil removal. Surfactants are classified by pattern analysis, based on the detergent contribution of the various factors in detergent systems.