Online detection of orientation of cellulose nanocrystals in a capillary flow with polarization-sensitive optical coherence tomography

Significant importance in the stiffness of materials, such as filaments and films, made of elongated components, has been attributed to orientation. Thus, the control of orientation during the manufacturing of materials has been the target of process optimization for long time. Measuring orientation during the process allows to better grasp the means to control it. In fact, such online tools would enable on-fly process control and optimization improving the flexibility with regards to the raw materials used, and the application requirements. In this article, we will discuss a method based on polarization-sensitive optical coherence tomography utilized as a light-weight online measurement tool of particle (here cellulose nanocrystals) orientation for the purposes of manufacturing next generation products by providing the appropriate interpretation of the retardation images with the help of modelling.