Miljkovic M., Ignjatovic V., Zarubica A.

The processes of textile improvement use huge water volume, electric energy and heat. The most of these processes use additives to accelerate or slow down the reactions. This permits a mass transport from liquid medium toward the textile surface in a reasonable time, without temperature increase. Analogously, in dyeing processes, transport of dyes from solution toward the fibre surface and further into its interior structure depends on time, temperature and various factors. Taking all together into consideration, a quality product may be achieved. Earlier studies suggested a possible ultrasound role in an improvement of some selected dyeing systems. Until now, mechanism of ultrasound influence on textile substrate, dye and the including processes taking place in solution and inside the fibres, is not clear yet. An establishment of a universal model seems to be inappropriate, taking into consideration a variety of dyes and fibres, their chemical composition, structure and the application procedure. An effect of ultrasound on each one reactant of reactive sulphonic dye – cellulose fibre system has been studied in this paper. The study of the textile substrate included an investigation of supramolecular and surface structures, swelling and mechanical features of cellulose fibres (cotton, viscose) exposed to different ultrasound frequencies (40, 200 and 600 kHz). It was studied kinetics of the dye hydrolysis in a homogeneous alkaline solution, as well as in a heterogeneous dyeing system. The results of our studies show mechanisms of ultrasound action on dyeing processes, influence of ultrasound on basic phenomena of transport, taking place in solution, polymer and textile. Based on the corresponding parameters correlations, an estimation of ultrasound application validity in dyeing processes of cotton – type textile substrates with reactive vinyl sulphonic dyes has been established.