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Analysis and Modelling Strategy of Water Imbibition Into Paper Network Using Synchrotron 4D Microtomography Data

Fournier, Mélanie LU (2025) In Master’s Theses in Mathematical Sciences BERM01 20251
Mathematics (Faculty of Sciences)
Abstract
In 2023, an in situ 4-dimensional high resolution synchrotron X-ray Tomography was
used to image an experiment in which paper strips were immersed in different liquids.
The paper strip material is the same that is used in the fabrication of paper straws at
Tetra Pak.
In this thesis, this data is used to analyse and model the interactions between the
liquid and the paper at the individual fibre level. Using observation of the data as well
as a Random-Forest based segmentation, the transport mechanisms of liquids inside the
paper fibre network were analysed. Consequently, the importance of water transport
stemming from both swelling and diffusion through the fibre network was revealed not to
be underestimated when compared to... (More)
In 2023, an in situ 4-dimensional high resolution synchrotron X-ray Tomography was
used to image an experiment in which paper strips were immersed in different liquids.
The paper strip material is the same that is used in the fabrication of paper straws at
Tetra Pak.
In this thesis, this data is used to analyse and model the interactions between the
liquid and the paper at the individual fibre level. Using observation of the data as well
as a Random-Forest based segmentation, the transport mechanisms of liquids inside the
paper fibre network were analysed. Consequently, the importance of water transport
stemming from both swelling and diffusion through the fibre network was revealed not to
be underestimated when compared to capillary action through the pore space inside the
fibre network.
Then, a diffusion based model is designed to simulate, in COMSOL, the swelling of
fibres. The resulting model shows promising results, but does not account for capillary
action. Further development of said model at the fibre scale could then lead to improved
modelling of paper behaviour at the macroscopic scale. (Less)
Popular Abstract
As the world shifts away from fossil-based products, paper-based materials offer a promising
alternative to plastic-based materials by being both recyclable and renewable. An
example of such a change in use of material is paper straws in Tetra Pak packages. Paper
straws are meant to be in contact with liquid, and it is therefore crucial to understand how
paper interacts with water. Despite the question seemingly being simple, the mechanisms
of liquid imbibition into paper are complex and still poorly understood to this day.
Using a technique called X-ray microtomography, and leveraging the power of the
MAX IV synchrotron beamline in Lund, Sweden, it is possible to get 3-dimensional images
of the paper at a submicrometre spatial... (More)
As the world shifts away from fossil-based products, paper-based materials offer a promising
alternative to plastic-based materials by being both recyclable and renewable. An
example of such a change in use of material is paper straws in Tetra Pak packages. Paper
straws are meant to be in contact with liquid, and it is therefore crucial to understand how
paper interacts with water. Despite the question seemingly being simple, the mechanisms
of liquid imbibition into paper are complex and still poorly understood to this day.
Using a technique called X-ray microtomography, and leveraging the power of the
MAX IV synchrotron beamline in Lund, Sweden, it is possible to get 3-dimensional images
of the paper at a submicrometre spatial resolution. The following experiment was
performed as part of an ongoing research project involving a collaboration between Lund
University, Tetra Pak, and Vinnova, called Real time 4D X-ray microtomography Imaging
and analysis of water transport mechanisms in sustainable paper straws. Paper strips,
which are made of the same material as the paper straws produced by Tetra Pak, are immersed
in different liquids and an image is taken every 90 seconds. This one of a kind 4D
(3D + time) dataset provides new insights into the complex interactions between water
and the constituent fibres of the paper at the microscopic scale.
In this thesis, an analysis of the data generated by the experiment is performed. The
qualitative analysis shines a new light into the phenomena at play, while the quantitative
analysis provides statistical data that can be used to accurately model these phenomena
numerically.
Numerical simulations are increasingly used nowadays as a virtual experiment framework,
thus reducing the need to iterate and experiment on potentially long and costly
physical prototypes. However, to be useful, they need to accurately reflect reality. Designing
a numerical model that does so requires extensive knowledge of the phenomena
that are to be simulated. In the second part of this thesis, a simplified numerical model is
proposed which is able to account for the measured swelling and expansion of the paper.
The results of this thesis showcase the potential of using high quality data to develop
more complex and realistic models, as well as provide possible directions in which to take
future work using the data. (Less)
Please use this url to cite or link to this publication:
author
Fournier, Mélanie LU
supervisor
organization
course
BERM01 20251
year
type
H2 - Master's Degree (Two Years)
subject
keywords
tomography, paper, fibre, simulation, 4D, synchrotron, X-ray
publication/series
Master’s Theses in Mathematical Sciences
report number
LUNFBV-3005-2025
ISSN
1404-6342
other publication id
2025:E72
language
English
id
9201646
date added to LUP
2025-08-06 15:13:36
date last changed
2025-08-06 15:13:36
@misc{9201646,
  abstract     = {{In 2023, an in situ 4-dimensional high resolution synchrotron X-ray Tomography was
used to image an experiment in which paper strips were immersed in different liquids.
The paper strip material is the same that is used in the fabrication of paper straws at
Tetra Pak.
In this thesis, this data is used to analyse and model the interactions between the
liquid and the paper at the individual fibre level. Using observation of the data as well
as a Random-Forest based segmentation, the transport mechanisms of liquids inside the
paper fibre network were analysed. Consequently, the importance of water transport
stemming from both swelling and diffusion through the fibre network was revealed not to
be underestimated when compared to capillary action through the pore space inside the
fibre network.
Then, a diffusion based model is designed to simulate, in COMSOL, the swelling of
fibres. The resulting model shows promising results, but does not account for capillary
action. Further development of said model at the fibre scale could then lead to improved
modelling of paper behaviour at the macroscopic scale.}},
  author       = {{Fournier, Mélanie}},
  issn         = {{1404-6342}},
  language     = {{eng}},
  note         = {{Student Paper}},
  series       = {{Master’s Theses in Mathematical Sciences}},
  title        = {{Analysis and Modelling Strategy of Water Imbibition Into Paper Network Using Synchrotron 4D Microtomography Data}},
  year         = {{2025}},
}