**3.2 Characterization of DBD treated fabrics and structural analysis 3.2.1 Time of water drop absorption**

Table 3 shows the difference between the wettability of the untreated and the plasmatically modified polyamide woven fabrics by measuring the time for complete water absorption into the material.


Table 3. Wettability results

246 Textile Dyeing

The level of dye penetration into fibers was visualised by fluorescence microscopy on polyamide transversal cuts. The fibers were embedded into an epoxy resin and transversal cuts of the fibers with 15 mm were prepared using a microtome (Microtome Leitz). Fibers' cross sections were analyzed by a fluorescence microscope LEICA DM 5000B at 40x

The color depth of dyed polyamide 6.6 was increased by using a reactive dye for wool dyeing (Lanasol Blue 3G), a reactive dye for cotton dyeing (Remazol Yellow Golden RNL) and a direct dye (Sirius Scarlet KCF), when different dosages of plasmatic discharge are used varying power of discharge and number of passages (Figure 3). The K/S values in polyamide samples depend on plasma conditions, being more intense for higher dosages.

Fig. 3. K/S values of dyed samples of polyamide 6.6 pre-treated with different discharge

Increase of dosage applied (a) Increase of dosage applied (b)

Fig. 4. Final dyeing baths corresponding to samples with increasing dosages of plasmatic

discharge – a) Reactive Lanasol Blue and b) Reactive Remazol Yellow Golden.

A significant difference in the quantity of residual dye is noticed (Figure 4) by comparing colors of the baths obtained after dyeing process of the samples submitted to different

**2.7 Fluorescence microscopy** 

**3. Results and discussion 3.1 Optimal plasma dosage** 

This criterion was used to choose optimal plasma dosage.

magnification.

dosages

dosages.
