Aramid, steel, and glass: characterization via cut performance testing, of composite knitted fabrics and their constituent yarns, with a review of the art

Aramid, glass, and steel have been compared for their performance in composite forms in protective applications, which are not the most usual ones. After underlining the importance of cut protection, a rather extensive review of the art in the domain of cut performance reveals that a good basis has been established, still leaving space for the study of non-coated, less uniformly interlocked composite yarn assemblies in the form of knitted structures or woven ones. Slightly departing from the traditionally friction-driven cut mechanism, those structures are distinguishable. This offers some elements for the long-awaited clarification of normalized test differences. Statistically, relevant families of commercial or semi-commercial products have been selected to address simultaneously the variability and the performance boundaries of those materials using instrumented ASTM cut equipment to obtain a “smarter” response of the material performance during its testing and to perform a “more sophisticated” data analysis beyond usually specified ones. The attempts to analyze more localized physical events open the door to micro or nanoanalysis of the fracture mechanism during the cut event which may differ from the traditional friction analysis. The contribution of meltable companion fillers, although not being the core of the study, could be translated to applications where those fillers become functional elements further improving the performance and synergism of the three basic elements, aramid, glass and steel. Previous study on the tribological properties of Kevlar® (DuPont’s registered trademark) composite fabrics stands as a natural prolongation of this study when applied to the knitted composite structures of this study.