COLOUR FASTNESS ANALYSIS OF PRINTED ELECTRONICS THROUGH THE FLEXOGRAPHY TECHNIQUE ON TEXTILE SUBSTRATES

The work is framed within Printed Electronics, an emerging technology for the manufacture of flexible electronic products such as electronic textiles. Among the different printing methods, interest on roll-to-roll flexography technique has increased because it allows continuous manufacturing and high productivity at low cost. Nevertheless, the incorporation of the flexography printing technique in the textile field is still very recent due to technical barriers such as of durability and withstanding bending, stretching, abrasion and washing. Specifically, the study is focused on investigating the colour fastness to wash and rubbing of electronic inks printed on textiles through the flexography process. By a comparison of the same ink printed on different flexible substrates it has been concluded that woven and nonwoven fabrics are a suitable option regarding colour fastness to wash instead of thin polymeric and paper substrates that tear at the wash machine. The ink volume transferred to the substrate should be optimized when conductivity and colour fastness to washing are the objectives, still, several coatings could also be applied after the printing. Concerning colour fastness to rubbing where poor results were obtained, a solution for an optimal electronic printing on textiles would be the surface substrates pre-treatment by applying different chemical compounds that increase the adhesion of the ink avoiding its absorption.