@article{2344c653-9e06-4eb6-b6d8-4c4e8b8268f0,
  abstract     = {{<p>Nonwoven fibre networks underpin filtration, insulation and geotextiles, where liquid uptake, redistribution and release govern performance. In needle-punched felts, barbed needles mechanically entangle fibres and partially reorient them towards the thickness direction (z), creating out-of-plane “pillars” and heterogeneity. While mechanical and structural consequences of needling are well documented, dynamic z-direction transport in partly saturated networks remains difficult to access due to opacity and sub-second timescales. Here we combine micro-CT (μCT) of dry structure with time-resolved X-ray radiography during droplet addition to quantify through-thickness transport as a function of saturation and needling intensity, using a compact Washburn-type descriptor for dynamics. Results show an exponential dependence of z-directional liquid transport on saturation, consistent with previous models for in-plane relative permeability of nonwoven networks. Additionally, increased needle-punch intensity reorients fibres towards the z-direction, forming preferential flow pathways that enhance through-thickness transport, even as single-phase permeability decreases. These findings underscore needle-punch as a key design parameter for tuning liquid transport in nonwoven fibre networks. The approach provides an experimental and modelling framework for dynamic, capillarity-driven transport in opaque fibrous materials.</p>}},
  author       = {{Wegele, Patrick and Yao, Zisheng and Tejbo, Jonas and Rogalinski, Julia K. and Rosén, Tomas and Groetsch, Alexander and Nygård, Kim and Asimakopoulou, Eleni Myrto and Villanueva-Perez, Pablo and Söderberg, L. Daniel}},
  issn         = {{0723-4864}},
  language     = {{eng}},
  number       = {{5}},
  publisher    = {{Springer}},
  series       = {{Experiments in Fluids}},
  title        = {{Time-resolved X-ray radiography of through-thickness liquid transport in partly saturated needle-punched nonwovens}},
  url          = {{http://dx.doi.org/10.1007/s00348-026-04201-6}},
  doi          = {{10.1007/s00348-026-04201-6}},
  volume       = {{67}},
  year         = {{2026}},
}