Tribological properties of woven para-aramid fabrics and their constituent yarns

Abstract

The tribological behaviours of woven fabrics made from Kevlar® (DuPont's registered trademark) yarns of different linear densities were compared with the friction properties of their constituent yarns with different surface treatments. The latter were examined with a traditional friction meter, and the woven fabrics were studied with a pin-on-disc tribometer in alternate and continuous sliding mode. Scoured fabrics, a poly(tetrafluoroethylene)-coated fabric, and fabrics made of surface-treated yarns (polysiloxane oil, hydrophobic paraffin or ester oil lubricant) were compared. These treatments are not representative of commercial Kevlar® yarn finishes but are suitable models for simulating various tribological situations. Both the yarn texture and the surface treatment have an influence on friction coefficient values. Relative humidity affects the friction coefficient only in the case of hydrophilic surfaces, whereas hydrophobic surfaces exhibit fairly constant tribological characteristics. The largest impact on friction seems to be evidenced by the linear density factor. This comparative tribological analysis could lead the way to correlations between yarn friction, weaving performance and woven structure tribological characteristics.