Nylon 6.6 dyeing behaviour for fibres of different levels of fineness

Nylon 6.6 microfibres are now commonly produced. During dyeing, these microfibres appear to be more accessible to both acid and disperse dyes, than thicker fibres. This phenomenon is enhanced with the use of small dye molecules. In this paper, the mechanism of fixation of disperse dyes is shown to be due to adsorption as well as dissolution. In nylon 6.6 the fraction of disperse dye adsorbed is greater than the fraction dissolved. The conditions of drawing are supposed to create imperfections in the amorphous phase. The amount of microvoids created in microfibres favours the adsorption phenomena of disperse dyes via polar bonds.