Deformation behavior and structural mechanics of needle punched nonwovens

The staple fiber needle punched nonwoven fabrics exhibit a very complex deformation behavior under uniaxially applied loads. The mechanical properties are highly influenced by the structural geometry. An index based on the number of fibers per unit area (INF) of the nonwoven fabrics has been developed to explain the relationship between the breaking load, breaking elongation, the lateral contraction during loading (Poisson's ratio) and the INF. The asymmetry of the deformation is highly influenced by the asymmetric orientation distribution of the fibers in the fabric.