Micromechanics of hydroentangled nonwoven fabrics

The mechanics of nonwoven fabrics is largely dependent on fiber properties, and other physical factors such as structural arrangement and degree of entanglement of the fibers. In this study, modeled and experimental stress–strain behaviors of uniaxially loaded hydroentangled nonwoven fabrics have been analyzed and compared. The theoretical values from the model were deduced from the measured properties of micro-samples, namely, fiber volume faction, orientation distribution and mechanical properties. Testing of the micro-samples was performed on a Deben Microtest Module fitted in the FEI Quanta 200 Scanning Electron Microscope. The experimental stress–strain results show that the structure is in the linear region when the modeled results approach the highest specific stress. Also, the theoretical models highly overestimate the specific stress of the hydroentangled nonwoven fabrics. The results show that the application of the model was limited in predicting tensile stress. Furthermore, a trapezoid method was used to quantify the actual deformation energy from the stress–strain graphs up to the ultimate tensile strength. The theoretical deformation energy was estimated and compared to the experimental values. The model was subsequently modified to improve its predictive capability.