The effect of water hardness on washing performance of built and unbuilt surfactants

Five different surfactants were used at 2.0% concentrations. The most and least effective were found to be Synthrapol N and Ahcowet RS respectively; based on their rating of whiteness index. Synthrapol N and Ahcowet RS were evaluated with the addition of sodium carbonate, sodium tripolyphosphate and a 1:1 combination of the two builders. In both cases the addition of a builder improved the cleaning efficiency of the surfactant. Although each builder alone improved the cleaning efficiency, the combination of sodium carbonate and sodium tripolyphosphate improved efficiency at a lower total concentration.