Clean Technology and Energy Saving of Leather and Wool Printing
Using Henna Extract and/or H-acid
A.A. Haroun1, H.F. Mansour2 and K. Haggag3
1National Research Centre, Dept. of Chemistry of Tanning and
2Faculty of Applied Arts, Helwan university, Textile Printing, Dyeing and Finishing Dept.,
3National Research Centre, Dyeing, Printing and Auxiliaries
Increasing demands on clean technology and energy saving in leather and textile colouration have led to the need for accelerated fixation, usage of eco-friendly colourants and safe chemical additives. An investigation was undertaken to study the effect of microwave heating on the fixation of printing paste containing natural dye (henna extract) and/or H-acid in presence of casein and sodium lauryl sulfate on leather and wool. It is important to note that the study included a comparison between the different mode of fixation (microwave and steaming). The effect of different conditions; dye types (henna extract and H-acid), dye concentrations, mordanting and fixation modes (microwave and steaming) on the colour strength, CIE-lab colourimetric data as well as the fastness properties of the printed samples were investigated. Results show that this application allows some possibility of energy conservation, reduction of process time and minimization of environmental pollution. It was found that, the colour strength and the overall fastness properties of the microwave printing fixation samples were significantly improved, especially, in case of henna extract, relative to the conventional steaming method. Moreover, saving of the dry step in the printing of leather and wool was achieved using microwave heating fixation. H-acid plays an important role, it acts as a dye and a mordant.