Influence of Washing on the Electric Charge Decay of Fabrics with Conductive Yarns

The aim of the research was to reveal features of the electrical charging and dissipation of charges in fabrics containing conductive yarns after washing. All fabrics investigated were woven at the Lithuanian Textile Institute as protective fabrics from incendiary discharges. Conductive yarns were inserted into the fabrics at specified intervals. The surface and volume resistance, shielding factor and half decay time were determined for the fabrics before and after 5 washing cycles. The influence of the shielding effectiveness of PES/Cot ton woven fabrics with silver plated filaments was investigated at different RH. Although the quantity of conductive yarns in the fabrics improves their electrostatic properties, the washing of the fabrics decreases all resistance values measured. The washing does not have a very big influence on the shielding factor and half decay time. It is shown that the vertical electrical resistance and surface resistivity are parameters whose values are very sensitive to the quantity of conductive PES/INOX yarns in the fabrics. Although knitted fabrics shrink more than woven ones, they have better electrostatic properties. Notwithstanding the influece of washing the fabrics tested have a sufficient shielding effect and can be used in work clothing to prevent the build-up of static charge.