Eco-friendly printing paste replacing urea-based formulations in cotton printing.

In textile printing, hydrotropic components are usually added to print paste formulations promoting the hydration of textile fabrics by disrupting the hydrogen bonding network between water molecules. For this purpose, urea is commonly used but nevertheless, its presence causes water eutrophication and their reduction or replacement by more environmentally-friendly products is required. In the present work, we have studied an alternative hydrotropic product (polyethylene glycol, PEG) to replace urea. A factorial design of experiments has been carried out to identify the factors that optimize several variables of interest such as viscosity of the printing paste and fabric colour strength. The results showed that a reduction of 70 wt% of urea was achieved by using PEG 400, while preserving the performance of printing formulation. The viscosity of these eco-friendly printing paste formulations was similar to that of the original urea-based formulations and, more interestingly, fabrics showed similar colour strength and fastness to those of fabrics printed by the conventional method. [ABSTRACT FROM AUTHOR]