Influence of Abrasion on Electrostatic Charge Decay of Woven Fabrics with Conductive Yarns

Abstract

Human body has quite low volume resistivity to act as a conductor and if insulated from earth it can accumulate electrostatic charge. The charge can be produced by contact electrification or by touching charged equipment or materials, which can cause hazardous, spark discharges. The aim of the research was to reveal the features of electrical charging and dissipation of charges in the woven fabrics containing conductive yarns after abrasion. All investigated fabrics were woven in Lithuanian Textile Institute as protective fabrics against incendiary discharges and electromagnetic radiation. Two groups of fabrics from polyester (PES) 16.7 tex f 96 (as weft), PES 8.4 tex f 72 (as warp) yarns and other two groups of fabrics from union polyester/cotton (65 % : 35 %) 15 tex × 2 (as warp and weft) yarns were manufactured for the study. Each group consisted of five fabrics differing by the fiber content. The conductive PES/INOX yarns were at different specified intervals inserted into one group of PES fabrics and one group of PES/cotton fabrics. Silver-plated yarns were correspondingly inserted into the other group of PES fabrics and other group of PES/cotton fabrics. The fabric surface resistivity, volume resistance, shielding factor and half decay time of fabrics were measured after abrasion for 5 000, 10 000, 15 000, 25 000, 35 000 and 45 000 rubs, and also with no abrasion. The values of surface and vertical resistances increased after abrasion. The half decay time became longer and values of shielding factor decreased. It was found that changes of surface after abrasion do have an influence to the tested fabrics. For fabrics, where surface fuzzing or pilling is seen, electrostatic characteristics are worse than for those with smooth surface. Therefore, it was found that while the number of conductive yarns inserted into the fabrics improved the fabric electrostatic properties, the abrasion led to the notable impairment of the protective power of the fabrics to incendiary discharges.