A new model has been developed that predicts the compression behavior of thick, nonwoven fiber assemblies at high stress levels. The model uses the Poisson distribution to describe how fibers are stacked on top of one another during web formation. The stress/thickness relationships developed are based solely on the compression properties of the stacked fiber mass. Effects predicted by the model include greater packing uniformity for increasing web weight, decreasing fiber diameter, and decreasing fiber transverse compression modulus. An expression for the fractional area of a compressed web that is actually under stress is also given. The stress/thickness behavior predicted by the model is compared to the measured compression characteristics of nylon, Spectra~®, Kevlar~®, and fiberglass needled batts. The measured and predicted behavior agree well enough in most cases to validate both the Poisson distribution approach to the placement of fiber mass in randomly formed nonwoven materials and the simple com-pressive stress relationships developed from it.
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