Bending Rigidity of Thermally Bonded Nonwoven Structures

Bending rigidity is one of the most important parameters affecting the fabric drape characteristics. In this research work, classic Freeston and Platt model, describing the bending behaviour of nonwovens specifically for thermally bonded, has been modified by accounting for number of bonds replacing the number of fibres in a unit cell. These bonds are responsible for constraining the relative fiber motion in the nonwoven structure. The anisotropic characteristics of thermally bonded nonwovens are revealed by analysing the bending properties in various test directions. In general, there is a good agreement between the bending rigidity values obtained from modified Freeston and Platt model and experimental work. However, the classic Freeston and Platt model has overestimated the bending rigidity of thermally bonded nonwoven structures. Furthermore, the effect of main fiber parameters including volume fraction, modulus and orientation characteristics has been investigated on the bending rigidity of thermally bonded nonwovens.