Posts Tagged hemp
Hemp as a Source of Highly Sustainable Fiber
Posted by Mylynedj in Fiber Facts on April 20, 2012
Hemp is a term commonly used for the low tetrahydrocannabinol (THC) strains of the plant Cannabis sativa (subsp. sativa) which is grown for industrial use. It is to be distinguished from C. sativa subsp. indica which has a poor fiber quality and is primarily grown for the production of recreational and medicinal drugs which can contain from 2% to over 20% THC. Oilseed and fiber varieties of Cannabis approved for industrial production contain only minute amounts of THC which is below 0.3%, not enough for any physical or psychological effects.
Hemp is one of the earliest domesticated plants known. Its first uses date back to the Chinese, in the 28th Century B.C. Industrial hemp has been grown in the U.S. since the first European settlers arrived in early 1600’s. George Washington, Thomas Jefferson and John Adams all grew hemp and actively advocated for commercial hemp production. In the 1800’s, hemp was a staple crop of American agriculture and was handled by the U.S. government like any other agricultural crop. More than 150,000 acres of hemp were cultivated as a part of the USDA’s “Hemp for Victory” program during WWII.
The tides would soon change for hemp in the U.S. The 1937 Marihuana Tax Act defined hemp as a narcotic drug, requiring that farmers growing hemp hold a federal registration and special tax stamp, effectively limiting further production expansion. Then the Controlled Substances Act of 1970 (CSA) adopted the same definition of Cannabis sativa that appeared in the 1937 Marihuana Tax Act. To date, more hemp is exported to the United States than to any other country, as the United States Government does not consistently distinguish between marijuana and the non-psychoactive Cannabis used for industrial and commercial purposes.
As a crop, hemp is one of the faster growing bio-masses known, producing up to 25 metric tonnes (1 metric tone = 1,000 kg) of dry matter per hectare (10,000 sq. m) per year compared to a normal average yield in a large scale modern agriculture which is about 2.5–3.5 t/ac. It grows very quickly in very diverse soil conditions, making it a highly sustainable and renewable commodity. It is also very environmentally friendly as it requires few pesticides and no herbicides.
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Traditionally, hemp fiber has been a very coarse fiber when raw, which made it well suited for rope production. Advances in breeding of the plants and treatment/processing of the fibers have resulted in a much finer, softer hemp fiber, which is ideal for weaving into hemp clothing and fabrics. It improves and softens with age and is also mildew resistant, making it an excellent yarn for towels, bath linens and carpet warp as well as in fine table linens and clothing. Hemp is over twice as strong as cotton and is the most durable of all natural textile fibers. Furthermore, it also holds its shape, stretching less than any other natural fiber. This prevents hemp garments from stretching out or becoming distorted with use. With this in mind, hemp yarns would also make ideal crocheted or knitted re-useable grocery bags. For free patterns visit: Tipnut.com (scroll down).