Effects of lignocellulose structure on single fiber tensile characteristics portrayal: a case of enset fiber

Fiber-leveltensile characteristics are vital for micromechanical analysis and mechanical modellingof materials and their composites. This portrayal depends on diameter estimation accuracy, as the applied load is determined from the testing machine. Inline, natural fibers possess an internal cavity; the diameter found using microscopy denotes the external diameter which is larger than the diameter pertaining to actual load-carrying cross-section. This study presents a new approach that estimates diameter considering lignocellulose structure and hydrophilicity, thereby enabling the portrayal of more accurate tensile strength values. First, the fibers’ diameter is measured using a laser microscope, on various spots axially and the internal cavity was then considered to determine the actual diameter. Thedensity of milled fibers is measured using Pycnometry. The diameter which relates to a solid load-carryingcross-section is identified using the relationship between density, mass and volume. The experiment design was framed and analyzed using Python and JMP Pro 13. The measured density of Enset is 1.38 g/cm3. The average overestimation of microscopy result issignificant; it is 27.7μm which is about 21.8%. This underrates the actual tensile strength of Enset fiber by about 37.5%. That is σext=0.627σact. This, in turn, would affect micromechanical analyses and mechanical modelling. Thus, the need to consider lignocellulose structure for testing the tensile strength of Enset fiber is inevitable and the method utilized in this study can be used forother natural fibers of the same nature customizing the context.