Plant fibers in general and hemp fibers in particular have great prospects for their use in various innovative applications such as ecological, biodegradable, and renewable resources with unique properties. Such properties together with the increased strength due to high-cellulose content and specific morphological parameters are widely used to produce plant fiber–based plastic composites. The properties of plant fibers that may influence the properties of composites depend on crop processing, but the basis for them is provided during fiber development in planta. It is known that two types of bast fibers are developed in the hemp stem: primary fibers formed from procambium cells and secondary fibers that originate as a result of cambium activity. Both types of fibers may significantly vary in their yield and quality depending on the variety and growth conditions. Differences in the anatomical and morphological characteristics of the two types of hemp fibers, together with peculiarities in the composition and architecture of cell wall, influence the technical parameters of the raw material quality. Based on our study of both primary and secondary fiber development in hemp stem that was focused on the two key stages, intrusive elongation and deposition of thick cell wall layers, we suggest the set of parameters that can influence the quality of the mature fibers and trace their biological origin.
Part of the book: Natural and Artificial Fiber-Reinforced Composites as Renewable Sources