2. Detergents

Detergents are surfactants that help remove soils from solid surfaces. Over and above reducing water's surface tension, detergents must adsorb onto the soil's surface to aid in spontaneous release. Detergents must also keeps the soil suspended to prevent re-deposition. 

Ø  Detergents are surfactants used  for removal of dirt.

Ø  Detergency involves:

•      Initial wetting of the dirt and the surface to be cleaned.

•      Deflocculation and suspension, emulsification or solubilization of the dirt particles
•      Finally washing away the 

dirt.http://d25smtqkk0nuqw.cloudfront.net/wp-content/uploads/2015/11/biorf11.gif

Following can be understand from the above figure:
1. Dirty Substrate (Any textile material)  come in contact with detergent or surfactant in the presence of water
2. Detergent molecules start coming toward dirt or soil. As the dirt is oily in nature hydrophobic tail come in contact with dirt and hydrophilic head of detergent molecule remain in water.

3. Slowly detergent surrounded dirt particles and pulling them out of substate
4. All the dirt particles removed from the substrate.