Hemp

Although chemotype I cannabis and hemp (types II, III, IV, V) are both Cannabis sativa and contain the psychoactive component tetrahydrocannabinol (THC), they represent distinct cultivar groups, typically with unique phytochemical compositions and uses.^[6] Hemp typically has lower concentrations of total THC and may have higher concentrations of cannabidiol (CBD), which potentially mitigates the psychoactive effects of THC.^[7] The legality of hemp varies widely among countries. Some governments regulate the concentration of THC and permit only hemp that is bred with an especially low THC content into commercial production.^[8][9]

Processing[edit]

Separation of hurd and bast fiber is known as decortication. Traditionally, hemp stalks would be water-retted first before the fibers were beaten off the inner hurd by hand, a process known as scutching. As mechanical technology evolved, separating the fiber from the core was accomplished by crushing rollers and brush rollers, or by hammer-milling, wherein a mechanical hammer mechanism beats the hemp against a screen until hurd, smaller bast fibers, and dust fall through the screen. After the Marijuana Tax Act was implemented in 1938, the technology for separating the fibers from the core remained "frozen in time". Recently, new high-speed kinematic decortication has come about, capable of separating hemp into three streams; bast fiber, hurd, and green microfiber.


Only in 1997, did Ireland, parts of the Commonwealth and other countries begin to legally grow industrial hemp again. Iterations of the 1930s decorticator have been met with limited success, along with steam explosion and chemical processing known as thermomechanical pulping.