Dyeing of cotton, Linen, Rayon, Wool, Silk and Mis
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Dyeing of cotton, Linen, Rayon, Wool, Silk and Miscellaneous Fibres:-
The application of dyes is essentially the same whether on silk, wool, jute straw, raffia, bleached, dyed cotton, or rayon (direct or sulphur colours), or mordanted cotton or rayon. Dyeing is started in a cold bath set with 1-4% of 28% acetic acid and 1% of nonionic dyeing assistant promote penetration and levelness and also prevent bronzing. These objectives are also attained effectively by adding the well-dissolved dyes in portions at 5 min. intervals. The bath is completely exhausted when the temperature has been raised gradually to 130-1600F in 1 hr. of dyeing. A final rinse completes the operation.
Although either pure or weighted silk can be dyed with basics as described above, pure silk is often dyed from a diluted broken boil-off liquor. Boil-off liquor is the soaping liquor resulting from boiling off the natural silk to remove impurities. It is broken with acetic, formic, or sulphuric acid. Such a method is especially advantageous for delicate shades where levelness is important.
