Page 56 - Advances in Textile Biotechnology

Developments in enzymatic textile treatments 35

Table 2.1 Representation of mechanical energy in the various process forms
(see text for key to symbols)

Processing Process step Process [c]
time
Impregnation Incubation Rinsing

Full continous/ Desizing rr s rr rr ss t cc
open width Scouring rr s rr rr ss t cc
form Bleaching r s rr rr ss t cc
Full continuous/ Desizing kk ss kk kk ss tt c
rope form Scouring kk ss kk kk ss tt c
Bleaching kk ss kk kk ss tt c
Pad batch–hot Desizing rr s n rr ss ttt c
bleach Scouring/ rr ss rr rr ss t ccc
bleaching
Discontinuous Jigger r ttt c
Jet k ttt c
Winch k ttt c

r mechanical energy owing to rollers bending fabric once over a roller;
rr mechanical energy owing to rollers bending fabric at least twice;
s squeezing once;
ss squeezing, at least twice;
k kneading of the fabric;
kk intensive kneading of the fabric;
t time consumption, an increasing number of ‘t’s indicates increasing
time consumption;
c concentration of chemicals used, an increasing number of ‘c’s indicates
increasing concentrations; and
n no mechanical energy available.
From Table 2.1, it is clear that there are many possible options for the pre-
treatment of fabrics and each option has its characteristic way to add
mechanical energy to the process. Since the mechanical energy is a key
factor in the performance of enzymes it is to be expected that enzymes
perform differently on the different systems presented in the table. It is
evident that there will be a strong relationship between the amount of
mechanical energy applied to the process and the time required to achieve
a good enzymatic performance. Therefore, a profound understanding of the
mechanical energy in these systems and its effect on the enzymatic pro-
cesses is a prerequisite for a successful introduction of enzymes in the
textile industry.

© Woodhead Publishing Limited, 2010