For such a simple question, why is the answer so complex? It starts with the understanding of what a cleaner is made of.
Since we rarely deal with solvent cleaning these days, let’s limit this discussion to aqueous cleaners. There is an extensive list of products that are incorporated into cleaners, and they all serve a function in one capacity or another. Here is a list of common additives and the functions they perform in a cleaning system.
Builders
A builder is the basic component of an aqueous cleaner and the workhorse of all components. Common builders are sodium hydroxide, potassium hydroxide and sodium silicates. Since these chemicals are difficult to rinse, it is important to have sound rinsing and alkaline neutralizing chemistry to avoid quality issues down the line.
Surfactants
Surfactants are also commonly referred to as “wetting agents” or “surface active agents” and will reduce the surface tension of the solution. There are literally thousands of surfactant formulations for formulators to choose from. The older technology cleaning systems would have the caustic breaking down the oils/soils while the surfactant “emulsified” them. This kept the oils/soils in solution and required further effort to crack the oils/soils from solution. The development of newer surfactant technology cleans the parts by lifting the oils/soils from the parts without chemically reacting with it. This technology works particularly well in spray cleaning applications, where the oils/soils can be skimmed and the cleaner gets longer useful life. The best of both worlds utilizes “weak” emulsifiers which will keep oils/soils soluble as long as the solution is agitated; then the emulsion breaks when the solution is static and the oils/soils can be separated from the solution.
Chelators
Chelators will keep metal ions in solution. Common chelators are sodium gluconate and EDTA. Although they are great for cleaning applications, they are a headache for waste treatment due to the strong bonding characteristics.
Sequestering Agents
Sequestering agents have a useful function by mating with hard water ions such as calcium and magnesium. Hard water ions come from tap water and can minimize the effectiveness of an aqueous cleaner without sequestering agents. Phosphate is one example of an effective sequestering agent.
Saponification
Saponification can be a good thing and a bad thing at the same time. Cleaners that are high in alkalinity can convert insoluble fatty soils to water soluble soaps. This keeps the soaps in solution which might be a disposal problem or foaming issue in spray cleaners. There is chemistry available to deal with these issues.
When considering your next aqueous cleaning application, contact an Asterion representative, who will ask the right questions to determine the cleaner that makes sense for your operation.