Time-resolved X-ray radiography of through-thickness liquid transport in partly saturated needle-punched nonwovens
Wegele, Patrick ; Yao, Zisheng LU
; Tejbo, Jonas
; Rogalinski, Julia K.
LU
; Rosén, Tomas
; Groetsch, Alexander
; Nygård, Kim
LU
; Asimakopoulou, Eleni Myrto
LU
; Villanueva-Perez, Pablo
LU
and Söderberg, L. Daniel
(2026)
In Experiments in Fluids
67(5).
- Abstract
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... (More)
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.
(Less)
- author
- Wegele, Patrick
; Yao, Zisheng
LU
; Tejbo, Jonas
; Rogalinski, Julia K.
LU
; Rosén, Tomas
; Groetsch, Alexander
; Nygård, Kim
LU
; Asimakopoulou, Eleni Myrto
LU
; Villanueva-Perez, Pablo
LU
and Söderberg, L. Daniel
- organization
- publishing date
- 2026-05
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Experiments in Fluids
- volume
- 67
- issue
- 5
- article number
- 56
- publisher
- Springer
- external identifiers
-
- scopus:105037453513
- pmid:42046788
- ISSN
- 0723-4864
- DOI
- 10.1007/s00348-026-04201-6
- language
- English
- LU publication?
- yes
- id
- 2344c653-9e06-4eb6-b6d8-4c4e8b8268f0
- date added to LUP
- 2026-08-17 15:55:50
- date last changed
- 2026-08-31 16:51:47
@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}},
}