Non-aqueous wool fiber dyeing process using reverse micellar approach

C-W Kan
The Hong Kong Polytechnic University,
Hong Kong

Keywords: wool fibre, non-ionic surfactant, non-aqueous dyeing, reverse micelle, reactive dye

Summary:

In textile industry, reactive dyeing using nanoscaled dye carrier in non-aqueous solvent mostly find several advantages such as well dispersibility, low viscosity and high diffusion into wool fabric matrix properties can result in shorter dyeing periods in comparison with the conventional water dyeing process. Reactive dye encapsulated in reverse micelle using non-ionic surfactant was used as an environmental friendly for sustainable textile coloration of wool fabric with primary emphasis on highly reduction of water usage for the solubilization of reactive dyes. The working temperature of non-aqueous dyeing is 88 °C, which is 10 degrees lower than in conventional water-dyeing process in terms of energy saving aspect. The obtained color strength in terms of K/S sum value is better than that in conventional aqueous dyeing. Dyeability of wool fibre with reactive dye from the reverse micellar solution was improved without incorporation of textile auxillaries such as electrolytes and chemicals such as acetic acid or sodium bicarbonate for pH adjustment. Optimization of dyeing and fixation process could be achieved in a one-bath reverse micelle solution, leading to a potential of lowering the operation costs and energy consumption. The used solvent can be recycled and reusable without generation of dye wastewater effluent. The calibration dyeing databases for both conventional water-based dyeing and non-aqueous reverse micellar dyeing were established, along with the dyeing of standard samples with predetermined concentrations. Computer color matching (CCM) was conducted by using different color difference formulae for both dyeing methods. The wool dyed by the reverse micellar dyeing system can achieve good to excellent color fastness (AATCC 61) comparable to that of the conventional dyeing system. Variety of eco-friendly and sustainable shades were developed and assessed in terms of colorimetric (CIEL∗a∗b∗ and K/S) properties measured using spectrophotometer under D65 illuminant (10° standard observer).