Microanalysis of Fibre Networks

Properties of fibrous materials such as strength, toughness and insulating properties are determined by the fibre network. LINX supports the development of microanalysis to visualize these.

Fibres play a key role in many materials and the properties of these materials rely on the arrangement of the fibre network. This includes heat conductivity, mechanical strength, stability, physical texture, etc. Several companies across a range of sectors are involved in LINX, they focus on developing models and analysis tools to map the fibre network with high precision.

Fibre materials are imaged using X-rays and depicting the result in 3D such that it is possible to see inside the material on micrometre scale. X-ray imaging is non-destructive and non-invasive, and can thereby record a fibre network in its natural form and shape.

In LINX we are employing advanced image analysis and simulation methods to accurately characterize the investigated samples and obtain key material features.

Materials containing fibres include stone wool used for insulation, textiles which can be wowen fibres, or wood fibres used in paper. Here we have studied textile and stone wool fibres.

Techniques and Methods

Many materials contain fibres such as stone wool used for insulation, textiles which can be wowen fibres, or steel wires in reinforced concreate, or it can be paper fibres. In this focus project the study concentrates around textile fibres and stone wool fibres aiming at providing information on the fibre structure.

The overall aim of this focus project is described as:

Develop a method for measuring, analyzing and describing the 3D morphology of complex fibre structures such as textile and stone wool fibres. This method will then be expanded to cover changes in the structure due to treatment. This will enable characterization of properties such as mechanical stability or degradation over time.

With this aim in mind different approches to reaching the aim have been studied. Segmentation of individual fibres provides information on the individual fibre which depends on the possiblity to identify each individual fibre. The fact that these complex fibre structures contain densly packed fibres that are touching neighbouring fibres in multiple positions complicates the analysis. Additionaly, cotton fibres are not circular in cross-section.

Analysing only a few individual fibres out of many fibres might not provide the information about the whole fibre structure, which was aimed for. Instead, for the cotton textile the analysis was based on estimating local thickness of the fibre which provided a statistical caracterization of the fibre structures. This has been used for extracting statistics of the different textile samples.

for stone wool, the analysis resulted in methods to study the destribution of fibre lengths in stone wool materials. Measuring fibre length is difficult, since fibre needs to be tracked in its full length, and tracking errors or limited field of view will skew the length distribution. An extensive statistical framework has been developed with the aim of validating the outcome of the methods for estimating fibre length distributions. These methods will be used to to study changes in the fibre length either as a function of production settings.

Project Information

Participants: Novozymes, ROCKWOOL, Technical University of Denmark.
Start date, end date:
April 2016 – March 2019
Complex fiber analysis (FP07.001, Fiber structure and dynamics).