Textile bleaching is one of the stages in the manufacture of textiles. All raw textile materials, when they are in natural form, are known as 'greige' material. This greige material will have its natural color, odor and impurities that are not suitable for clothing materials. Not only the natural impurities will remain on the greige material but also the add-ons that were made during its cultivation, growth and manufacture in the form of pesticides, fungicides, worm killers, sizes, lubricants, etc. The removal of these natural coloring matters and add-ons during the previous state of manufacturing is called scouring and bleaching.
Mercerisation is a treatment for cellulosic material, typically cotton threads, that strengthens them and gives them a lustrous appearance. The process is less frequently used for linen and hemp threads.
Improving lustre (silky look, in tension mercerization only).
Improving tensile strength.
Improved dimensional stability.
Increasing uniformity of dyeing & improving color yield (savings in dyestuff).
Improving Elasticity or Stretch material (in slack mercerization only).
Calendering is a process by which fabric ran through hot, heavy rollers at the mill. This flattens the fabric, seals the weave, and leaves one side of the fabric shiny while the other is matte/dull in appearance. This process is done to make the fabric downproof, increase wind resistance, and improve hand feel.
It makes the fabric feel thin, glossy and papery.
It is also done on cottons, linens, silks, and various man-made fabrics.