Use of high-active alpha olefin sulfonates in laundry powders

Alpha olefin sulfonates (AOS) have been used successfully for many years in laundry and personal-care products throughout Asia. Among their documented positive attributes are good cleaning and high foaming in both soft and hard water, rapid biodegradability, and good skin mildness. AOS has commonly been marketed as approximately 40%-active aqueous solutions. However, with the increased importance of compact powder detergents produced by processes other than spray drying, high-active forms of AOS including 70%-active pastes and 90+%-active powders are now being utilized for that product sector. In this regard, the rheological properties of non-Newtonian AOS and AOS/additive pastes at relevant process temperatures were measured and found potentially suitable for agglomeration processes. Also, the relationship of AOS powder particle size to surfactant solubility at various wash conditions was examined to allow determination of the optimal size for both detergency and processing of laundry powders. Both paste rheology and powder morphology are critical factors for the successful use of high-active AOS in compact powder detergents.