Quality characteristic: finishing – combing, gassing and mercerising
Uniformity, fineness and purity are other important quality characteristics of single and ply yarn. These things are attained by various textile finishing processes.
Combing removes all the foreign bodies that can be found on any cotton plantation (e.g. animal and vegetable particles), as well as removing short cotton fibres and reshaping or straightening out medium-length cotton fibres.
Gassing (or singeing) removes any protruding filaments using a flame, making the ply yarn more uniform and removing any final protruding fibre ends. It is these protruding ends that tend to form little balls when a fabric is used, otherwise known as pilling.
With mercerisation, the structure of the cotton fibres is altered and refined using caustic soda. The fibres swell, becoming rounder and more uniform in nature, which gives the fabric a silky sheen and makes it more robust.