The Different Types of Hemp Fiber

Fiber is one of the most valuable parts of the industrial hemp plant. Hemp fiber can be used as a woven or non-woven material. This includes being used for textiles like clothing and upholstery, as well as industrial applications, such as building and construction materials (commonly called hempcrete), bioplastic packaging, composite panels, paper, and much more.

The stalk of the hemp plant contains long fibers (bast) and short fibers (hurd). Bast fibers are located on the outside of the plant's stalk, like bark, while hurd is located in the inner core. Bast fibers lend to the plant’s strength and measure anywhere from 3-15 feet long. The long fibers are used for woven textiles, while the short fibers are used for paper pulping, animal bedding, and bioplastics, just to make a few applications. American farmers are showing significant interest in producing hemp for fiber as processing infrastructure - decortication - is being developed around the country.

Hemp genetics play a major role in fiber yield and quality. While hemp fiber research is very premature, we know that different hemp varieties will produce vastly different types of fiber. The production method of a hemp crop and the quality of fiber will be greatly affected by the application of the end-product for which it is best suited.

Fiber yield and quality are also affected by seeding density. A higher seeding rate will produce a higher plant population and ultimately a more densely planted crop will encourage vertical growth and less branching. This will likely result in a higher fiber yield.

More information on harvesting hemp fiber will come as processors continue doing research and development. We are eager for processors to identify the specifications of hemp fiber that is best suited for their decortication technology. That may include what genetics are optimal or how the crop is harvested.

Generally, growers will use a sickle bar mower to harvest hemp fiber. Typically, they will allow the windrowed stalks to go through a process of field retting. This allows microbes to slowly break the chemical bonds that hold the stalk together, ultimately allowing easier separation of the long bast fibers from the woody core. This is another piece to the puzzle that fiber processors are learning more about through research and development. In the coming year, it is likely that processors will able to provide more insight on best practices for hemp fiber production.