Ramie
Ramie | |
---|---|
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Rosales |
Family: | Urticaceae |
Genus: | Boehmeria |
Species: | B. nivea
|
Binomial name | |
Boehmeria nivea |
Ramie (pronounced:
A second type, known as green ramie or rhea, is believed to have originated in the
Cultivation
Ramie is one of the oldest
When the plant begins flowering, or just before, it signals both a decline in growth and the plant being at its maximum fibre content, and is harvested.[3] Stems are harvested by cutting just above the lateral roots or by bending the stem. This enables the core to be broken and the cortex can be stripped from the plant in situ.[3]
After harvesting, stems are
The dry weight of harvested stem from crops ranges from 3.4 to 4.5 t/ha/year. A 4.5-ton crop yields 1,600 kg/ha/year of dry undegummed fiber. The weight loss during degumming can be up to 25%, giving a yield of degummed fiber of about 1,200 kg/ha/year.[3]
The fiber extraction occurs in three stages. First, the cortex (bark) is removed; this can be done manually or by machine. This process is called decortication. Second, the cortex is scraped to remove most of the outer bark, the parenchyma in the bast layer and some of the gums and pectins. Third, the residual cortex material is washed, dried, and degummed to extract the spinnable fiber.[3]
History
Ramie has been grown in
Taiwan's aboriginal people have used ramie for millennia in fabric production and ramie is still used to create traditional garb which is worn in the festivals which have not been banned (mostly related to decapitation and stabbing enemy captives).
Ramie was used to produce an open-weave fabric called mechera, used for shirts and dressing gowns suitable for warm climates. The French painter Raoul Dufy designed in the early 20th century patterns for prints on mechera used by the French shirtmaker Charvet.[5]
Brazil began production in the late 1930s with production peaking in 1971. Since then, production has steadily declined as a result of competition from alternative crops, such as soybeans, and from synthetic fibers.[1]
Properties
Ramie is one of the strongest natural fibers. It exhibits even greater strength when wet. Ramie fiber is known especially for its ability to hold shape, reduce wrinkling, and introduce a silky lustre to the fabric appearance. It is not as durable as other fibers, so is usually used as a blend with other fibers such as cotton or wool. It is similar to linen in absorbency, density, and microscopic appearance. It does not dye as well as cotton. Because of its high molecular crystallinity, ramie is stiff and brittle and will break if folded repeatedly in the same place; it lacks resiliency and is low in elasticity and elongation potential.[6]
Cellulose (wt%) | Lignin (wt%) | Hemicellulose (wt%) | Pectin (wt%) | Wax (wt%) | Microfibrillar angle (°) | Moisture content (wt%) | Density (g/cm3) |
---|---|---|---|---|---|---|---|
68.6 – 76.2 | 0.6 – 0.7 | 13.1 – 16.7 | 1.9 | 0.3 | 7.5 | 8.0 | 1.50 |
Fiber diameter (mm) | Fracture load (N) | Tensile strength (MPa) | Fracture strain (%) |
---|---|---|---|
0.034 | 0.467 | 560 | 0.025 |
Uses
Despite its strength, ramie has had limited acceptance for textile use. The fiber's extraction and cleaning are expensive, chiefly because of the several steps—involving scraping, pounding, heating, washing, or exposure to chemicals. Some or all are needed to separate the raw fiber from the adhesive gums or resins. Spinning the fiber is difficult due to its brittle quality and low elasticity; and weaving is complicated by the hairy surface of the yarn, resulting from lack of cohesion between the fibers. Greater utilization of ramie may depend upon development of improved processing methods and the need to find plastic alternatives.[9]
Ramie is used to make such products as industrial sewing thread, packing materials, fishing nets, and filter cloths. It is also made into fabrics for household furnishings (upholstery, canvas) and clothing, frequently in blends with other textile fibers (for instance when used in a mixture with wool, shrinkage is reported to be greatly reduced when compared with pure wool). Shorter fibers and waste are used in paper manufacture. Ramie ribbon is used in fine bookbinding as a substitute for traditional linen tape.
For the 2010 Prius, Toyota began using plant-derived plastics made from the cellulose in wood or grass instead of petroleum. One of the two principal crops used is ramie.
Ramie is also used as an
In Vietnam, ramie leaves are called "cây lá gai", which is a main ingredient in making "bánh gai" or "bánh ít lá gai", a Vietnamese glutinous rice cake. The leaves give the cake its distinct color, flavor and fragrance.
In the Chinese
Ramie is also occasionally used in the construction of high performance rowing oar shafts. Mahe Drysdale used sculling oars made with ramie during the 2016 Rio Olympics where he won Gold in the Men's 1X Scull.[citation needed]
Producers
See also
References
- ^ a b c Ramie: Old Fiber - New Image Archived copy at the Library of Congress (September 17, 2002).
- ISBN 0-19-861225-7.
- ^ a b c d e f g Beda Ricklin Swicofil AG Textile Services. "Swicofil". Swicofil. Retrieved 2013-11-09.
- ^ "Ramie". Wild Fibres. Retrieved 2016-07-31.
- ^ Raoul Dufy créateur d'étoffes (PDF) (in French). Mulhouse: Musée de l'impression sur étoffes de Mulhouse. p. 22. Retrieved 2016-07-31.
- ISBN 0-13-025443-6
- .
- .
- OCLC 912384285.
- ^ "Britannica Online". Britannica.com. Retrieved 2013-11-09.
Further reading
Chisholm, Hugh, ed. (1911). . Encyclopædia Britannica (11th ed.). Cambridge University Press.
External links
- Ian Wood Ramie: the different bast fibre crop Australian New Crops Newsletter