Abaca
The abaca fiber is obtained from the leaves of the banana-like
plant (same genus) Musa textilis (banana family, Musaceae). The fiber is also
called Manila hemp from the port of its first shipment, although it has no relationship with hemp, a bast fiber. The mature plant has 12–20 stalks growing
from its rhizome root system; the stalks are 2.6–6.7 m tall and 10–20 cm thick
at the base. The stalk has leaf sheaths that expand into leaves 1–2.5 m long,
10–20 cm wide, and 10 mm thick at the center, the fibers are in the outermost
layer. The plant produces a crop after 5 years, and 2–4 stalks can be harvested
about every 6 months.
In the Philippines, the principal supplier of abaca fiber, the fibrous layer in
the sheath is separated with a knife between the layers, and the strips of fiber
containing layers, called tuxies, are pulled off and cleaned by hand to remove
the pulp. In Indonesia and Central America these operations are performed
mechanically. Hand- and spindle-stripped fiber is graded for braids, fine textiles,
and cordage; decorticated fiber is another class. The abaca fiber has a large lumen and the presence of silicified
plates is not unusual.
Abaca fiber is unique in its resistance to water, especially salt water, and
it is used for marine ropes and cables, although it has been largely replaced
by synthetic fibers. Abaca fiber is the strongest of the leaf fibers,
followed by sisal, phormium, and henequen; it is also the strongest among the
papermaking fibers. It is used for sausage casings and it is the preferred fiber
for tea bags because of its high wet strength, cleanliness, and structure that
permits rapid diffusion of the tea extract.
Cantala, Manila Maguey
Agave cantala is a member of the agave family
(Agavaceae) that includes sisal. It originated in Mexico and was transported to
Indonesia and the Philippines, where it is now produced commercially. The
plant grows in a moist, humid soil. The fiber is extracted in Indonesia mechanically by a decorticator (raspador) and in the Philippines by retting in seawater
and cleaning by hand or with a decorticator. The cantala fiber is lighter in color
than other agaves, and its strength depends on its preparation.
Caroa
Caroa is a hard leaf fiber, resembling sisal, obtained from
Neoglaziovia variegata, a plant of the pineapple family (Bromeliaceae) growing
wild in eastern and northern Brazil. The sword-shaped leaves are 1–3 m long
and 2.5–5 cm. wide. The fiber is extracted by hand scraping after beating or
retting. The fiber is used for cordage and acoustic material.
Henequen
Agave fourcroydes grows in Mexico where it was first cultivated by the Mayans in the Yucatan (Yucatan Sisal). The plant produces for
20–30 years. The lower bottom leaves, which are up to 2 m long and 10–15 cm
wide, are cut, machine decorticated, and cleaned. Henequen fibers are white to
yellowish red and are inferior to sisal in strength, cleanliness, texture, and
length, the other grading criteria. Henequen is grown for local use in Cuba
(Cuban Sisal) and El Salvador. Twine, small ropes, coarse rugs, and sacks are
made commercially from henequen.
Istle
Istle is the general name for several agave species and related plants
producing short, coarse, hard fibers. The commercial name is tampico. The plants
from which the fibers are harvested include tula istle (A. lophantha), jaumave
istle (A. funkiana), and palma istle (Samuela carnerosana). They are grown in
central and northern Mexico. The fibers are recovered by hand scraping and
drying; the palma istle is gummy and requires presteaming. The jaumave istle
fibers closely resemble animal bristles in brushes.
Mauritius Hemp
Mauritius hemp, also called piteira, is obtained from
Furcraea gigantea, also a member of the Agavaceae. The plant is mostly grown
on the island of Mauritius, but is also harvested in Brazil and other tropical
countries. The leaves are longer and heavier than those of the agaves. The
fiber is extracted by mechanical decortication. It is whiter, longer, and weaker
than sisal fiber. Because of its color it is used in blends.
Phormium
The Phormium tenax plant yields a long, light-colored, hard
fiber also known as New Zealand hemp or fiax, although it has none of the bast
fiber characteristics. The plant is a perennial of the Agavaceae with leaves up to
4 m long and 10 cm wide. The fibers are recovered by mechanical decortication.
Sansevieria
This genus of the Agavaceae is a perennial also known as
bowstring hemp from its use in bow strings. The plant is native to tropical
Africa and Asia but is widely grown, mainly as an ornamental plant. It is of
minor importance as a fiber plant, even though the fiber is of high quality. The
highest grade of S. cylindrica fiber is greenish yellow, very soft and fine, and
compares with sisal in strength.
Sisal
The true sisal fiber from Agave sisalana is the most important of
the leaf fibers in terms of quality and commercial use. Originating in the tropical
western hemisphere, sisal has been transplanted to East Africa, Indonesia, and
the Philippines. It is named after the port in the Yucatan from which it was first
exported. The sisal plant leaves grow from a central bud and are 0.6–2 m long,
ending in a thorn-like tip. The fibers are embedded longitudinally in the leaves,
which are crushed, scraped, washed, and dried. The highest grades are further
cleaned with a revolving drum. The growth of the sisal plant depends on water
availability; it stores water during the wet season and consumes it during
periods of drought.
The sisal
fiber is coarse and strong, but compared with the abaca fiber it is infiexible,
although with a relatively high elongation under stress. It is also resistant to
salt water. The principal applications are in binder and baling twine and as a
raw material for pulp for products requiring high strength. A large pulp mill is
operating in Brazil based on sisal.