Characterisation of fibre entanglement in nonwoven fabrics based on knot theory

Owing to the structural complexity, the entanglement of fibres within nonwoven fabrics is generally characterised in indirect way by determining fabric mechanical properties using destructive testing and empirical modelling. Using elements of knot theory, a new approach is presented in this paper to characterise degree of entanglement in webs and nonwoven fabrics by topological representation of the fibrous assembly. The identification of fibre crossings followed by calculation of splitting number gives a numerical estimate of the degree of entanglement that can be potentially linked to the mechanical properties of the fibrous assembly.