The answer depends on the ingredient mix. Some formulas are designed as neutralizers which would pre-dominantly include acids. Other formulas go beyond this with other acidic builders and higher amounts of surfactant to qualify as an emulsifying rinse.
An acidic emulsifying rinse is designed to work with all carpet pre-sprays. When used as your extraction rinse and you accomplish several things at once. You receive a cleaning and rinsing boost as you need it. Acidic builders are designed to attach to the soil emulsified by any pre-spray and rinse it thoroughly out of the carpet at high dilutions. If the emulsification process has not been completed by the pre-spray, then it will help finish this process in the rinsing step. In addition, the carpet fibers will be neutralized of any alkaline residues by the acidic neutralizers. It typically includes a low foaming surfactant with good wetting characteristics and also helps hold the diverse ingredients in a stable solution. The right surfactant forms a brittle residue which along with an added polymer help leave the carpet in a state where resoiling issues are not a matter of concern. Finally, some ingredients inhibit corrosion of metal parts in your equipment.
Acidic emulsifying rinses do not need to be turned off at the truck when pre-spraying with the Hydro-force sprayer. Tests indicate that the pH of even moderate alkaline pre-sprays are not significantly affected and that the diverse cleaning additives in acidic emulsifying rinses balance any impact on the pH of the pre-spray. Within the last five years, powdered acidic emulsifying rinses have been developed which have proven to be better cleaners based on their different levels of key ingredients.
Use acidic emulsifying rinses for brighter and cleaner carpets while reducing problems such as browning, wick back, resoiling, and stiffness. In most cases, an acidic emulsifying rinse will be the only rinse needed as it is aggressive enough for restoration rinsing and neutral enough to be used on wool and natural fiber upholstery. In short, keep it simple and achieve superior results by relying on the acidic emulsifying rinse of your choice.