Laser Diffraction for the Defectoscopy of Cellulose Filaments

Filaments produced from the wet spinning of Cellulose nanofibrils are a promising alternative to those derived from fossil fuels. These filaments are the strongest bio-based filaments currently available, with potential uses in the production of high-performance textiles. However, establishing what the weakest point of such filaments is, has yet to be conclusively determined. We demonstrate the potential of laser diffraction in conjunction with the Fraunhofer approximation as a defectoscopy technique. Finding the thinnest point on the sample provides the most accurate estimate, with a mean distance-to-break-point of 1135 μm. The tendency of the measured point to be less slit-like was determined to be the most precise measure (48 % of all cases). A ’Failure factor’ metric was elaborated to attempt to combine measured width and similarity. With an accuracy of 935 μm, this is the best possible estimate using the methodology presented here. Our results demonstrate the need for further refinement of the technique. This study presents a basic starting point for further development. Performing high-resolution tomograms of the samples to quantify cross sectional circularity or incorporating machine learning would improve accuracy and precision. With laser diffraction being such a rapid and inexpensive method, as well as non destructive, such instruments could be integrated into the production process, providing real-time defectoscopy and quality control.