engleski

ULTRASOUND IN TEXTILE FINISHING AND DYEING

In this paper, an application of low and high frequency ultrasound on textile finishing and dyeing is discussed. Ultrasound treatment has the potential for use in bleaching due to localized high temperatures and pressures, and formation of highly active oxidizing species such as hydroxyl radicals (HO•), hydrogen radicals (H•), hydroperoxyl radicals (HO2•) and H2O2. Polyester fabrics were bleached at pH 7 using 279 kHz and 817 kHz. The significant effect of high frequency ultrasound on bleaching polyester fabric is obtained for the first time. It is interesting to note, that high whiteness degrees are achieved in ultrasonic bleaching without any addition of hydrogen peroxide. On the other hand cotton fabric was washed using low frequency ultrasound and interesting results were obtained in terms of whiteness, yellowness and hydrophility. Comparison between conventional and low frequency ultrasound (20 kHz) assisted dyeing of wool, polyamide and cotton was performed and found that US assisted dyeing results in greater dye exhaustion under the same experimental conditions as conventional dyeing in a shorter time and so we are dealing with process intensification. More, spent dyebath presents lower ecological parameters values, what means that US assisted dyeing contribute to the reduction of water pollution.

Ultrasound; finishing; bleaching; dyeing

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