What Is Aqueous Cleaning?
Aqueous cleaning is a process that uses a solution of detergent in water to remove organic and inorganic contaminants from an item. Detergents can be complex formulations containing a number of components, each having a specific function but, in simple terms, they fall into two, basic categories:
1. Those that chemically react with organic contaminants, converting them into water-soluble products.
2. Those that emulsify the organic contaminant with water.
Within each of these broad categories, detergents encompass a wide range of chemical types and so it is important to match their chemistries with the nature of the substrate and the contaminants to be removed.
Cleaning is normally carried out at elevated temperature to increase the rate of chemical reaction. This is further enhanced by mechanical action, usually in the form of spraying, either in air or under immersion, ultrasonic irradiation of the liquid, or agitation of the workload within the liquid. The type of mechanical action utilised depends on the type of detergent, the geometry of the items to be cleaned and the standard of cleanliness required. Furthermore, depending on the type of detergent, and the standard of cleanliness required, it may be necessary to follow the wash stage by one or more rinses in water, which may be purified. If completely dry components are required, it may also be necessary to include a hot-air drying stage.