Pretreatment of fabric

Pretreatment of fabric prior to whitening application.

The fabric at the loom stage (i.e. Grey cloth) contains yellow and brown impurities, which are partly removed from them by scouring (Boiling under pressure in an alkaline liquor in the presence of a powerful detergent & stain removers). The colour of some of the residual impurities (Which are not removed by the scouring treatment) is destroyed usually by bleaching treatments under controlled condition of pH, Time, Temperature and the Concentration of the bleaching agent, so that hydrolysis (Degradation or Tendering) of the polyester does not take place. Finally for achieving brilliant whitening effect Fluorescent brightener are applied.