Chemistry Reference
In-Depth Information
Lunk [189] examined polymerization processes in a DBD under normal pressure
with fluorocarbons. He could find good hydrophobicity on plasma-treated technical
textiles.
8.2.3.3.1.3 Plasma Cleaning of Textiles
During textile manufacturing, plasma-aided processes can be used to remove sizing
agents, mineral oils, or acrylate-based spin finishes, which form a film around the
yarn [186].
Other applications are the purification and disinfection of textiles. In this process,
the textiles are exposed to the plasma in different devices and by special methods.
Different plasma reactor constructions on the basis of DBD configurations were used
in the experiments, partly described in [62,190]. The different installations help to
judge the impact of different effects. Figure 8.36 shows the comparison of these
versions after the plasma treatment with air carrier gas.
The results show a clear degradation of the odor strength measured in odor
units [ou]. Compared to the untreated sample, this outcome occurred in all three
constellations. Evidently, one can reach an uncritical odor threshold.
Figure 8.37 presents the results of the microbial tests. We carried out different test
series to prove that plasma procedures can be applied for the disinfection of textiles.
Here we performed two different test series with different initial concentrations of
E. coli
.
The group on the left shows results of the treatment in the discharge gap of a DBD
with two different frequencies: positive pulse voltages of 7.5 kV and a treatment time
of 30 min.
With the treatment in the discharge gap and a frequency of 50 Hz, a reduction of
the germ number in the range of about approx. 2 log 10 steps was observed. The best
result, namely, more than 6 log 10 steps, was obtained by using 500 Hz.
5000
Untreated
4000
3000
2000
1000
0
Ion extraction
SD-DBD
In the gap
of DBD
Stacked
DBD
FIGURE 8.36
Odor strength after different treatment procedures.
