Page 55 - Advances in Textile Biotechnology

34 Advances in textile biotechnology

rinse out the impurities. The process steps of desizing, scouring and bleach-
ing are treated according to the same pattern (impregnation–incubation–
rinsing). For each process step, different impregnation and incubation units
can be distinguished depending on the time, temperature and mechanical
energy necessary to achieve the desired result.
In the second type of installed base for continuous treatment processes,
the fabric is in rope form. Impregnation is done in a rope impregnation unit,
followed by incubation in J-boxes and rinsing in J-boxes alternated with
rope-squeezers. Characteristic of this process is the kneading of the fabric

by filling the J-boxes completely with fabric in rope form and pushing the
fabric through the J-box. The latter is only possible when large amounts of
fabric are in the J-box and therewith long impregnation, incubation and
rinsing times are achieved.

2.2.2 Pad batch–hot bleach process
The pad batch–hot bleach process is an open width treatment. The fabric
is impregnated in an impregnation bath in which the fabric is guided by
rollers into and out of the bulk. After impregnation, the fabric is rolled on
an A-frame and incubated for several hours. After incubation, the fabric is
rinsed in washing compartments and consecutively impregnated with
bleaching agents. For impregnation, high concentrations of bleaching agents
(>100% pick-up) are added on the fabric. The fabric is incubated in a
steamer and after incubation rinsed in washing compartments.

2.2.3 Discontinuous pre-treatment
In a discontinuous installed base, the fabric is guided into the machine and
transported/moved in the same compartment. The distinguished types of
installed base are jigger, jet and winch. On a jigger, the fabric is moved from
one roller, via the treatment bath containing the treatment agents, to the
opposite roller (and vice versa). In a jet, the fabric is guided in rope form
in a J-box. The fabric is made endless and guided out of the bulk through
a pipe to the loading point of the J-box. In the J-box the fabric is kneaded
and pushed forward for the next tour.
The winch is the same type of installed base as the jet. The difference is
in the transport of the endless fabric. The fabric is ‘stored’ in the bulk and
taken out of the bulk by the winch. After passing the oval winch, the fabric
is again laid down in the bulk to be pushed and kneaded again.
The mechanical energy in the different process forms is represented in
Table 2.1. The symbols used in the table are:

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