Modeling the compression-induced morphological behavior of nonwoven materials

Nonwovens have the most complex morphologies in textile materials and they are often being compressed in a range of applications. The morphology of a typical nonwoven is defined in terms of fiber orientation, fiber volume fraction, number of fiber-to-fiber contacts, distance between the contacts, porosity, and pore size distribution. In this study, an attempt has been made to predict the morphological characteristics of nonwoven materials under the state of compression. A concept of compression ratio has been introduced in predicting the fiber volume fraction at a defined level of compression strain that has significantly influenced the other morphological characteristics of nonwoven materials. A mechanistic model of pore size distribution of nonwoven has been proposed by updating the structural and morphological parameters under predefined compressive stresses. A comparison has been made between theoretical and experimental pore size distributions of compressed nonwoven fibrous materials. In addition, the out-of-plane fiber orientation distribution was experimentally obtained by analyzing the two-dimensional (2D) cross-sections of fibers in the thickness direction.