Role of Radiation Treatment as a Cost-Effective Tool for Cotton …
327
Fig. 8 Effect of redox reagents on vat dyeing of irradiated cotton fabric using irradiated vat dye
solution
amount shows that MW treatment is a cost-effective tool for the dyeing process using
Vat Red 10.
Arshad [47] designed the study to observe the effect of different parameters on
color strength of cotton fabric which is dyed with Reactive Black 5. It was observed
that MW treatment for 6 min. to dye solution and fabric has given good color depth
(K/S) (Fig. 9). Similarly, un-irradiated cotton used for dyeing gives good and darker
shades as compared to irradiated fabric. Because after employing irradiation the large
size of the dye molecule become disintegrate into smaller ones [48, 49]. Upon dyeing
the molecules rush towards the fabric evenly and diffused regularly to make covalent
bonding, where after dyeing washing with hot and cold water did not fade the color.
Hence microwave irradiation of dye solution for 6 min. is recommended to get darker
shades and acceptable fastness characteristics. Good color strength was obtained at
60 °C for 50 min. using a dyeing bath of pH 9 keeping material-to-liquor ratio
1:75 (Fig. 10). Colorfastness properties assessed after dyeing the fabric at optimal
conditions were improved fair to good by using microwave radiation (Table 9).
0
2
4
6
8
10
12
14
16
18
20
2
4
6
K/S
Control
RC/RS
NRC/RS
RC/NRS
Simultaneously
Radiation Time (min.)
Fig. 9 Effect of irradiation time on the color strength of cotton fabric dyed with Reactive Black 5
dye