Scouring
Wool must be scoured before it can be processed into yarn and fabric. The scouring process aims to remove contaminants from wool through agitation in a detergent solution (or suitable solvent). Agitation must be performed in a way that minimizes ‘entanglement’ or ‘felting’, while adequately removing contaminants.
Removing grease
For effective grease and dirt removal, the aim is to spread the water over the complete surface of the fibres, loosen and remove the grease and dirt, and then suspend the molecules of grease and dirt in the liquor so that they can be rinsed away. The detergent, with the required surfactant properties, does this.
While there are various types of detergents (anionic, cationic, non-ionic), in general, a detergent
the molecule has:
+ a hydrophilic ‘head’ (which has an affinity for
water and is repelled by oil and grease)
+ a hydrophobic ‘tail’ (which has an affinity for
oil and grease and are repelled by water).
