Even through, fabrics are already dyed or printed, but there
will be processed in finishing touch. The final process is needed to make
fabrics suitable for intended uses. This final stage in the processing is
called finishing. Most finishing is performed in the same plants as dyeing or
printing and can be classified into either aesthetic finishes or functional
finishes.
Pretreatment is a basic finishing process in which the fabric
undergoes a cleaning operation to rid of soil and additives that might have
accumulated during the weaving or knitting stage. It is required procedure
before any dyeing, printing or application of other finishes can be done. This process
for cleaning varies depending on the fiber, impurity present, and fabric contraction.
In cotton, cotton blend, silk and manmade fiber fabrics, the
process is called boiled off. This process involves the fabric to be treated
with soap or detergent, rinsed, and dried. Additional enzyme solution can be
applied to remove starch.
In woolen and worsted fabrics, the process, similar to
boiled off, is called scouring. To remove oil, a solvent is applied
additionally.
Woolen and worsted fabrics may undergo an additional pretreatment
called carbonizing, which cellulosic impurities are removed through the use of
sulfuric acid.
Bleach and optic brighteners, also pretreatments, can be
applied to natural fabric to attain a pure white color.
