The increasing demand for sustainable alternatives to synthetic fibres in the automotive industry has intensified interest in natural and bio-based materials. This thesis investigates a novel approach to extract and process wood-based fibres suitable for textile applications, with a particular focus on their potential use in automotive textiles. The study began with an initial characterisation of raw wood fibres using Favimat single fibre testing and FTIR spectroscopy to determine their mechanical and chemical properties. A mechanical separation method employing a drawing frame was first explored, and a theoretical model of the drafting forces involved was developed to understand the fibre extraction mechanism. 

To improve fibre separation efficiency, ultrasonic vibration separation was introduced. The cavitation forces were modelled, and an experimental setup using a 24 kHz sonotrode in a 500-litre water bath was applied. Power levels ranging from 100 to 360 W and amplitude settings from 50% to 100% were tested on both untreated and pre-drafted samples. The results demonstrated significantly improved separation in pre-drafted samples, highlighting the synergistic effect of mechanical and ultrasonic treatments. Post-treatment characterisation revealed a substantial softening of the fibres, with the elastic modulus decreasing from 8.15 GPa to 3.4 GPa, a reduction of approximately 58.3%, indicating enhanced fibre flexibility and potential spinnability. 

This research contributes to sustainable material development by offering an effective hybrid method for fibre separation while reducing chemical reliance. The findings can support the industrial scaling of eco-friendly fibre extraction methods, promoting sustainable innovation in the textile and automotive sectors.