Hemp is a versatile plant that has been used for centuries to make a variety of commercial and industrial products, including ropes, textiles, clothing, shoes, food, paper, bioplastics, insulation, and biofuel. Hemp (Cannabis sativa) is an annual herb of the Cannabaceae family that is cultivated for its bast fiber or edible seeds. It is sometimes confused with cannabis plants that are used to produce marijuana and hashish. Hemp contains only small amounts of tetrahydrocannabinol (THC), the compound that produces psychoactive effects on humans, compared to marijuana or hashish production.
The hemp plant has thin, rod-shaped stems that are hollow except at the tip and base. Its leaves are compound with a palmeate shape and its flowers are small and greenish-yellow in color. Seed-producing flowers form elongated spike-shaped clusters on pistillate or female plants while pollen-producing flowers form branched clusters on staminate or male plants. Hemp was first cultivated in China around 2800 BC and spread throughout Europe during the Middle Ages.
It was planted in Chile in the 16th century and a century later in North America. Hemp is grown in temperate zones as an annual crop from seed and can reach heights of up to 5 meters (16 feet).Crops grown for fiber are densely seeded and produce plants averaging 2 to 3 meters (6 to 10 feet) tall with almost no branching. Plants grown for oilseeds are planted further apart and are shorter with many branches. Maximum yield and quality is achieved by harvesting soon after plants reach maturity, indicated by full blooms and free pollen discharge from male plants.
The fibers are obtained by subjecting the stems to annealing, drying, grinding, and stirring processes that separate the woody portion from the long and fairly straight fiber or line. Fiber strands are usually greater than 1.8 meters (5.8 feet) long and have individual cylindrical cells with an irregular surface. The fiber is strong and durable and is used for twine, for example. Some specially processed hemp has an off-white color and an attractive sheen and is used to make linen-like fabrics for garments. Hemp fiber can also be used to make bioplastics that are recyclable and biodegradable depending on the formulation. Hemp can also be used as an alternative to wood pulp in some cases; it is often used in paper making and is a sustainable alternative to fiberglass insulation in buildings.
Hemp can be used to make “hempcrete”, a composite material made of hemp and a lime binder that can be used similarly to traditional concrete in no-load applications. The main uses of hemp fiber were rope, sacks, carpets, nets, straps, clothing industry products such as garments, bags, shoes, glasses, belts etc., paper making products such as cellulose content of approximately 70%, composites made of hemp fiber that can replace synthetic fiber composites reducing dependence on plastics and artificial fibers. Hemp can also be grown as food (the seed), but at least in the UK cultivation licenses are not available for this purpose. Liver enzyme activity in patients with multiple sclerosis on a Hot-nature diet and co-supplemented hemp seeds intervention with evening primrose oils has been studied. Hemp can grow on most land suitable for agriculture while forests and tree farms require large tracts of land available in few places. CBD products are only federally legal if they are derived from hemp and contain less than 0.3 percent THC. A comparison of fish oil, flaxseed oil, and hemp oil supplementation on selected parameters has been studied.