sisal

1 a plant fiber used for making rope [syn: sisal hemp]

2 Mexican or West Indian plant with large fleshy leaves yielding a stiff fiber used in e.g. rope [syn: Agave sisalana]

English

Pronunciation

• Rhymes: -aɪsəl

Noun

1. A Central American plant, of the genus Agave, cultivated for its sword-shaped leaves that yield fibers used for rope.
2. The fibre of the plant

Sisal or sisal hemp is an agave Agave sisalana that yields a stiff fiber used in making rope. (The term may refer either to the plant or the fiber, depending on context.) It is not really a variety of hemp, but named so because hemp was for centuries a major source for fiber, so other fibers were sometimes named after it.

Sisal plants consist of a rosette of sword-shaped leaves about 1.5 to 2 meters tall. Young leaves may have a few minute teeth along their margins, but lose them as they mature. Sisals are sterile hybrids of uncertain origin; although shipped from the port of Sisal in Yucatán (thus the name), they do not actually grow in Yucatán, the plantations there cultivate henequen (Agave fourcroydes) instead. Evidence of an indigenous cottage industry in Chiapas suggests it as the original location, possibly as a cross of Agave angustifolia and Agave kewensis.

In the 19th century, sisal cultivation (the plant being propagated via offsets), was spread worldwide, from Florida to the Caribbean islands and Brazil, as well as to countries in Africa, notably Tanzania and Kenya, and Asia. Among flax, hemp, abaca, sunn hemp (Crotalaria juncea) and other agro-based fiber species, annual sisal production is the second largest worldwide, after cotton; refer to the statistical databases by FAO, the United Nations Organisation for Food and Agriculture (www.fao.org). Sisal fibers are typed by properties relational to the performance of the fiber. Researcher Sara Kadolph has found that sisal fibers are smooth, straight and yellow and can be long or short. Since sisal is fairly coarse and inflexible, Kadolph finds that sisal is used by itself or in blends with wool and acrylic for a softer hand. Sisal is valued for cordage use because of its strength, durability, ability to stretch, affinity for certain dyestuffs, and resistance to deterioration in saltwater. Sisal is used by industry in three grades, according to www.sisal.ws. The lower grade fiber is processed by the paper industry because of its high content of cellulose and hemicelluloses. The medium grade fiber is used in the cordage industry for making: ropes, baler and binders twine. Ropes and twines are widely employed for marine, agricultural, and general industrial use. The higher-grade fiber after treatment is converted into yarns and used by the carpet industry. Traditionally, sisal has been the leading material for agricultural twine (“binder” and “baler” twine) but the importance of this is diminishing with competition from polypropylene and other techniques evolving. Apart from ropes, twines and general cordage sisal is used in low-cost and specialty paper, dartboards, buffing cloth, filters, geotextiles, mattresses, carpets, handicrafts, wire rope cores and macrame.

Researchers reporting on www.nnfcc.co.uk have published fiber extraction information on sisal fiber. In the process of decortication, leaves are crushed and beaten by a rotating wheel set with blunt knives, so that only fibers remain. All other parts of the leaf are washed away by water. Decorticated fibers are washed before drying in the sun or by hot air. Proper drying is important as fiber quality depends largely on moisture content. Artificial drying has been found to result in generally better grades of fiber than sun drying. Dry fibers are machine combed and sorted into various grades, largely on the basis of the previous in-field separation of leaves into size groups.

References

• G. W. Lock, Sisal (Longmans Green & Co., 1969)
• Howard Scott Gentry, Agaves of Continental North America (University of Arizona Press, 1982) pp. 628-631