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10.
Dyeing
fibers: b) Indigo Vat blue 1 (--> blue jeans)
What
you will need
Indigo
(Vat Blue 1) (VB),
sodium dithionite = Na2S2O4, piece of
cotton or a piece of bleached old jeans.
Two
vials
50 ml, Leukosilk as labels, tweezers, tissue paper, straw spatula,
white towel paper, disposable gloves, hot plate.
Step
1:.Into a 50 mL bottle introduce:
0.1 gr of indigo, 0.5 gr. of Na2S2O4
and 0.1 gr. of NaOH.
............Mix
the contents and heat on a hot plate to 80-100°C (with stirring)......
Step
2 (Photo 2):
Add a piece of cotton to the dyeing bath and let it dye
for 1-2 minutes.
Step
3: Take the pieces of fiber out of the bath (with pincette),
rinse well with water and put it on a white towel paper. Watch what happens.
Question:
What
is the Dyeing mechanism of indigo?............................................Dyeing
with Test Stains.
Copyright:
Mordechai Livneh......back......go
on....German.................................last
modifications: 22.04.2003