Saminathan Ratnapandian

Mordant	CuSO4.5H2O
FeSO4.7H2O
Concentration (g/l)	15	5
Dyeing sequence	Pad → Dry → Steam	Pad → Steam → Dry
Mordanting sequence	Pad → Steam → Dry	Pad → Steam → Dry

3. Evaluation

The wettability of untreated and plasma-treated fabrics was evaluated according to the methods described in Section 2.2.3.3. Dyed fabrics were conditioned prior to assessing their colour strength and fastness properties according to the procedures described in Section 2.2.3.

6. Results and discussion

   1. Fabric wettability

It was observed that plasma-treated wool fabric instantaneously absorbed a drop of water. Similarly, wicking height in excess of 5 cm in the given time was measured for all plasma-treated wool fabrics. As evident from the data presented in Table 4.3, over identical periods of measurement, the wicking length appeared to be independent of plasma-gas type and treatment duration. In comparison, untreated wool showed a wicking length of 1.0 cm only. The above observations and results are in agreement with the findings of Sun and Stylios [151] and Shekar ad Bajpai [152] who report increased absorbency and wicking when wool was treated with plasma. Another study
[160] exposed similar fabric to helium plasma, under conditions identical to the present investigation, and determined that a 1 second exposure to plasma was sufficient to make the surface hydrophilic. It was established that this was primarily due to surface modification only and did not involve removal of the fatty acid layer.
On the other hand, cotton did not display any substantial difference in absorbance or wicking between untreated and treated fabrics. This may be due to the intrinsic hydrophilicity of bleached and mercerised cotton, which is not significantly increased by plasma treatment.

Table 4.3 Wicking test results