A normal washing machine soaks clothes in soapy water, agitates them, then rinses and spins them dry. Wool, silk and certain polyester fibres can shrink or lose colour in washing machines.
In dry cleaning, clothes are sprayed with a liquid solvent and tossed gently in large, profession-grade machines that double as dryers.
The majority of dry cleaners use a highly toxic petroleum-based solvent called perchloroethylene, or ‘perch’, which cannot be touched or inhaled.’Green’ dry cleaners now use liquified CO2.
The final step in dry cleaning is to press the clothes using industrial steam presses.