Bast plants have a remarkable variety of uses. Bast fibers extracted from these plants are used in textiles, apparel, ropes and cordage, paper and composite fabrication, among other applications. The bast fibers can provide unique properties in textile structures, while providing alternative, renewable, fiber supplies for cotton based and/or petroleum based fiber materials. Bast seeds yield oils for several end-uses, e.g., food grade oils, personal care products, paint additives, etc. Bast plants are compelling crops to harvest due to the broad uses, the wide geographic footprint most bast plants have for growing, and the typical yields.
Despite the variety of uses for bast plants, these plants have been developed toward either seed production or fiber production, but not necessarily seed and fiber production. More specifically, bast plants that primarily yield seeds for oil production and planting, however, do not typically produce the fibers suitable for textile production. Bast plants for seed production may have short fiber lengths and lower fiber yields. For example, flax plants (Linum usitatissimum L.) for fibers are taller, yield more fiber, have lower oilseed content and produce less seeds compared to flax plants for seed production. In addition, bast seed plant production substantially outpaces the production of bast fiber plants, thus bast fibers suitable for textile applications have a limited supply.
Extracting fibers from bast plants and conditioning them into a state suitable for yarn and fabric formation is a complex, expensive process. Typically, bast plants are cut, laid in the field and the stalks are allowed to rett for some period of time, e.g., a week to a month or more depending on the climate. Retting begins the process of separating pertinacious materials from the fibers, and the fibers from the woody core of the plant. The retted stalks are then decorticated. Decortication as used herein means removing the outer layers of the stalk and exposing the fibers. Following decortication, the fibers are intended for yarn formation, typically using long-line or wet-yarn spinning systems, as is known the art.
Harvesting through decortication, however, does not necessarily produce fibers suitable for modern high speed yarn spinning operations, e.g., cotton and/or cotton blend spinning systems. The amount of capital investment in process modifications required to process bast fibers on existing spinning systems exceeds the return that running such fibers on those systems could provide.
There is a need, therefore, to address the processing of bast plants prior to decortication so that the fibers resulting from decortication are better suited for modern yarn spinning systems.