Dry cleaning of electroconductive layers screen printed on flexible substrates

Smart textiles and wearable textile systems are up to now a growing research field, with a view to applications such as monitoring vital signs or environmental parameters through garments. These developments require new materials such as electroconductive textiles. As a result, research into screen printing of conductive silver inks onto textiles has emerged. In this study, screen printing is used to print four kinds of silver-based conductive inks on a flexible foam and a nonwoven substrate. The screen printing method is chosen because it is a low cost and user friendly technique to obtain flexible and lightweight conductive fabrics. For the evaluation of the electrical properties the square resistance of the printed fabrics is measured after repeated dry cleaning cycles. The printed textiles studied here show good electrical properties after printing (< 0.05 /). However, after 60 dry cleaning cycles, the conductivity decreased considerably. Consequently, in order to improve washability, a protective polyurethane layer was put on top of the printed samples. In this case, the resistivity remained below 2.3 / after 60 dry cleaning cycles.