Submitted to: Composite Interfaces
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/7/2007
Publication Date: 4/28/2008
Citation: Foulk, J.A., Akin, D.E., Dodd, R.B. 2008. Processability of flax plant stalks into functional bast fibers. Composite Interfaces. 15(2-3):147-168.
Interpretive Summary: The objective of this article is to summarize the components and their use in the newly established Flax-PP. The USDA Cotton Quality Research Station is now complemented by the USDA Flax Fiber Pilot Plant which both exist for the utilization and testing of natural fibers. Results are important in showing that flax fiber can be produced successfully to address ARS priorities for new crops, improved rural economies, and improved global competitiveness. Research on flax fiber production, enzyme-retting, and standards development is urgent to support interest in the US, and globally as well, for cost efficient, value-added fibers for sustainable agriculture and new bio-based products. Testing methods and flax pilot plant improvements are expected 1.) to increase the use of natural fibers in the development of various natural fiber composites, 2.) to increase processing efficiency, and 3.) to assess the impact of new cultivation practices and fiber varieties on fiber utilization.
Technical Abstract: Flax (Linum usitatissimum L.) is an agricultural crop that is being considered as cost effective alternative to glass in composites. Flax is nature's composite with strong bast fibers held together in bundles adn located in the outer regions of the plant stem between the outermost cuticle-epidermis layre and the innermost, woody tissues. Agricultural production of this crop is environmentally beneficial because it is produced through photosynthesis and considered a naturally renewable and sustainable material. Its use in bio-based composites could help lessen our dependence on fossil fuels today and into the future. Processability of plant stalks into usable fiber requires retting which selectively removes pectinaceous and matrix substances thus separating cellulose fibers from non-fibrous substances and easing mechanical cleaning. To facilitate research on bast fiber retting and subsequent processing, a pilot plant based on commercial equipment is required to quickly and effectively evaluate these processes. The Flax Fiber Plant (Flax-PP), designed and modified after the 'Unified Line', is the only research facility of this type in the US, effectively processes and extracts bast fibers plant stalks. Plant stalks can be processed through different series of equipment depending upon starting quality and desired final properties. Each processing step creates a fiber product and byproduct both with potential uses in composites. Uniform quality of natural fibers is currently a drawback for efficient processing. The USDA Flax-PP also contains a separate research component for enzyme-retting plant stalks to fundamentally engineer fibers with desired properties using recently developed ASTM International flax fiber standards.