CORRELATION BETWEEN SPRAY CLEANING DETERGENCY AND DYNAMIC SURFACE-TENSION OF NONIONIC SURFACTANTS

The role of temperature and dynamic surface tension (DST) in spray-cle aning processes in industrial applications was investigated with nonio nic surfactants. Relative performance data for various ethoxylates (de rived from primary alcohols or nonylphenol) were obtained by a spray-c leaning method. The spray-cleaning method was developed to screen and identify optimum surfactants, formulations, and conditions for spray-c leaning applications. It is introduced here as a means to mimic spray- cleaning processes by (timed) spraying of a cleaner solution under pre ssure onto a soiled substrate. Results of this investigation indicated that temperature and DST play major roles in the soil-removal process . Observed temperature trends are typical of nonionic surfactants' clo uding phenomena. Optimum cleaning was observed at specific temperature s. Also, nonionics with shorter hydrophobes exhibited the best deterge ncy. Spray-cleaning detergency was compared to the DST because spray c leaning involves a dynamic interfacial process. New interfaces are con stantly being created. Results showed that the surfactants with the lo west DST exhibited the best soil removal. This correlation can allow f or a fast cost-effective means for screening potential candidates and reducing development time for industrial spray-cleaning applications.