Reliability evaluation of automated analysis, 2D scanner, and micro-tomography methods for measuring fiber dimensions in polymer-lignocellulosic fiber composites

Composite processing strongly affects the size of lignocellulosic fibers, and consequently the mechanical properties of the final product. Using a reliable method for the analysis of fiber length and diameter distributions is thus crucial for the understanding of fiber behavior during processing. In this study, three different techniques, X-ray microtomography, 2D scanning and automated fiber analyzer, were compared in terms of their reliability for the characterization of dimensions of two kinds of lignocellulosic fibers, hemp and miscanthus, in polymer-natural fiber composites. Statistical analysis was employed to interpret fiber size distributions. The study confirmed that interpreting the dimensions of natural fiber is still a difficult task. The inherent limitations of the measuring methods make each technique complementary to the others in terms of length scale. The choice of the technique is, therefore, strictly dependent on fiber dimensions and the aim of the work.