Chemical Emulsion in Industrial Cleaning
An emulsion is a dispersion of one liquid in another with which it does not mix, such as oil in water, stabilised by an emulsifier, usually a surfactant.
In cleaning, emulsion is one of the mechanisms by which greasy soil is removed. Water alone does not dissolve oils or fats. Surfactants position themselves at the interface between the grease and the water, with the lipophilic part towards the grease and the hydrophilic part towards the water; they reduce the interfacial tension, break the grease into small droplets and keep them dispersed so that they are carried away with the rinse and are not redeposited. In alkaline detergents, emulsion adds to the saponification of fats.
An emulsion can be oil-in-water (the most common in cleaning) or water-in-oil. Its stability depends on the type and amount of emulsifier (see HLB), the temperature, the ratio between phases and the presence of salts. When it breaks, the phases separate; in some processes this is desirable, for example to separate oil from wastewater.
Some Instaquim products whose technical data sheet states that they emulsify grease:
- Quimigras (pH 1 %: 12.0; neat or diluted up to 10 %): «disperses and emulsifies grease» on griddles, fryers, ovens and grills; do not use on aluminium.
- Filter (pH 1 %: 12.8; from 2 to 10 % by immersion): powder degreaser for kitchen utensils and hood filters; do not use on aluminium.
- Desgrasol MO (mix with water 1:4): degreaser for engines and machinery; the sprayed emulsion forms a foam that clings to vertical surfaces. Leave to act for 5–10 min and rinse with pressurised water.