Novel ultra filtration method of direct black 168, dyeing and ink-jet printing to cotton and polyamide Fibres

The dye Direct Black 168 was purified using ultrafiltration technology and water based ink-jet inks were prepared for digital printing applications. The suitability of the inks for novel printing applications was evaluated via measurement of pH, conductivity, surface tension and viscosity over a period of 90 days. The inks were applied to cotton and polyamide fabric by digital printing. Also, dyeing with the dye before and after ultra filtration was done. Colour measurements and fastness properties were performed for the dyed and digitally printed samples. The results were promising and this paves the way for the production of environmentally friendly ink jet inks using pure direct dyes for the digital printing of cotton and polyamide through the formulation of suitable printing techniques.