The dyeing of polyolefin fibers in supercritical carbon dioxide part II: The influence of dye structure on the dyeing of fabrics and on fastness properties

Dyeing of gel-spun polyethylene (PE) fibers of low and high draw ratio, polypropylene (PP) fibers, and poly(ethylene terephthalate) (PET) fibers was carried out in supercritical CO2 at 280 bar and in water under optimum dyeing conditions at 120 degrees C. Reflectance measurements show that, in both media, disperse azo dyes with a naphthalene moiety give much deeper colours than benzoazo or anthraquinone dyes. With most of the naphthylazo dyes, PP fibers gave a value of five for the light- and washing-fastness at 40 degrees C. The values for PE and PET fibers are generally lower. Because of the existence of only hydrophobic interactions between the polyolefin fibers and the dyes, the colour-fastnesses of the dyeings to sublimation in storage are in the range from three to four.