Which Is Better – Solvent, Aqueous or Semi-Aqueous Cleaning?
Cleaning involves the removal of a contaminant from the surface of a component. In determining the most suitable process for a particular application, it is important to consider a number of factors:
- The nature of the component e.g. the materials of construction, its geometry, whether it is susceptible to corrosion etc.
- The nature of the contaminant e.g. whether it is organic or inorganic, polar or non-polar, liquid or solid, soluble or insoluble.
- The impact of previous working on the contaminant e.g. whether its nature has changed due to temperature or pressure, whether it is fresh or has aged or hardened.
There is no definitive answer to which process is best, since they all can achieve similar standards of cleanliness across the vast majority of applications. All three processes offer advantages and disadvantages:
Solvents are generally considered to be hazardous chemicals but cleaning processes are generally quick, simple and effective. Aqueous and semi-aqueous cleaning chemicals are considered to have advantages from a health and safety perspective but cleaning processes are generally more complex and slower.
All three technologies impact on the environment. Aqueous impacts in terms of energy and water consumption, and effluent disposal, whilst the environmental impact of solvents relate to their initial manufacture, release to atmosphere during use, and disposal of waste.
By the correct selection of process and equipment, it is possible to utilise the advantages of each technology whilst effectively managing the potential disadvantages.