Meltblown fiber mats and their tensile strength

The present work deals with an experimental and theoretical study of the tensile properties of meltblown fiber mats at the elastic and plastic stages of deformation up to the ultimate catastrophic failure of material. The meltblown nonwoven mats were subjected to uniaxial loading and their stress–strain dependences were measured using a 100 N capacity Instron machine (model 5942R). This revealed the dependences of Youngʹs modulus and the hardening parameter on strain. These dependences are linked to the micromechanical behavior of individual fibers and fiber–fiber junctions. The proposed theoretical model described the experimental stress–strain dependences accounting for both factors: (i) the strength-hardening related to unraveling of polymer macromolecules in individual fibers, and (ii) opening of microcracks with increasing strain/stress in the fiber–fiber junctions and individual fibers, which results in a decrease in effective elastic moduli. The model is also capable of describing stress–strain dependence of individual fibers.