NATURAL FIBRE
Natural Fibres include wool from sheep and fibre from alpaca, angora rabbits, cashmere and angora (mohair) goats, silk from insects (silkworms), and plant fibres such as cotton, flax and linen, nettle and hemp.
· Animal fibres
· Silk & silkworms
· Plant fibres
Natural fibers are those that occur in fiber form in nature. Traditionally, natural fiber sources are broken down into animal, plant, or mineral. Fibers from plant or vegetable sources are more properly referred to as cellulose-based and can be further classified by plant source. They may be separated from the plant stalk, stem, leaf, or seed. Fibers from animal sources are more properly known as protein-based fibers. They are harvested from an animal or removed from a cocoon or web. Mineral fibers are those that are mined from the earth. Except for silk, all natural cellulose- and protein-based fibers are obtained in short lengths and are called staple fibers. Silk is a continuous filament fiber.
Cellulose-Based
Fibers
Cellulose-based fibers consist of bast, leaf, and seed-hair fibers. Bast fibers
come from the stem of the plant and include flax, hemp, jute, and ramie. Leaf
fibers are stripped
from the leaves of the plant and include manila and sisal. Seed-hair fibers are
collected from seeds or seed cases and include cotton and kapok.
· Cotton, obtained from the cotton seed, is the best-known and most-used natural cellulosic fiber. Cotton fiber is discussed in detail of this document.
· Flax is the bast fiber of the flax plant, used to make linen fabric. The plants are cultivated and grown in such a way as to produce long, thin stems. The plant is pulled from the ground for processing. The non-fibrous material in the stem is rotted away in a process called “retting.” Once retting is complete, the fibrous mass is rinsed and dried. The fiber is separated from the woody portion of the decomposed material by breaking and “scutching” (scraping). “Hackling” refers to combing the scutched fibers to separate the long and short fibers. The fiber is then spun, and S-twist is inserted, to produce linen thread.
· Hemp is a coarse, durable bast fiber from the plant Cannabis sativa. It is processed into a usable fiber in the same way as flax. It is used primarily for industrial and commercial
textiles,
especially cords, twine, and rope.
· Jute is a bast fiber from the stem of plants in the genus Corchorus, processed in the same way as flax. It widely used for industrial end uses such as sacking, burlap, twine, and
backing
for tufted carpets.
· Kapok is from the seed pods of the Java kapok tree (Ceiba pentandra). The seed pod is similar to the cotton boll; however, the dried fibers are easily shaken off the seed. A
buoyant
fiber, kapok is used primarily in life jackets, as special stuffing for pillows,
and in some mattresses. It is not spun into yarn.
· Manila is from the leaf stalks of the abacá plant (Musa textilis). The fibers are separated from the fleshy part of the leaf stalk. Manila is generally used in rope and cordage.
· Ramie is a bast fiber from the stalk of the ramie plant (Boehmeria nivea), also known as “China grass.” The plant is a perennial shrub that can be cut several times a year once
mature.
The cut plant’s stalks are peeled or retted to remove the outer woody covering,
revealing the fine fibers underneath. Degumming removes pectins and waxes,
followed by bleaching, neutralizing, washing, and drying. The fiber is similar
to flax, but more brittle. Ramie can be spun alone or with other fibers,
especially cotton.
· Sisal is from the leaves of plant Agave sisalana. The leaves are cut when the plant is about four years old, and the fibers are separated from the fleshy part of the leaf. Sisal has
industrial uses, most commonly as a rug or carpet backing.
Protein-Based Fibers
Protein-based fibers are from animal sources, most commonly the hair of the
animal. Animal-hair fibers are long-staple fibers, ranging in length from 2.5
to 10 inches or more. Silk is a natural protein fiber extruded by the silk
worm. With a length of over 500 yards, it is classified as a filament fiber.
· Wool is a fine hair fiber from sheep. In labeling, the term “wool” also may be used to identify fibers from other fleece animals, such as the Angora goat, Cashmere goat, camel, alpaca, llama, and vicuña.
Sheep-wool fiber can be sheared from the living animal or pulled from the hide
after slaughtering. Sheared or clipped wool is superior to pulled wool. Sheep
normally are sheared only once a year. Lamb’s wool is wool from sheep under 8
months of age. “Virgin wool” (or “new wool”) comes from the first shearing of
the animal and is most highly prized. (The term “virgin wool” is also used to
mean wool that has never previously been processed.)
1. Alpaca is the long, fine hair fiber from the alpaca, which is a relative of the camel native to South America. It is shorn from the animal once every two years. The soft, fine undercoat is used in textiles.
2.
Angora is the long, fine hair fiber from the
Angora rabbit. It is not to be confused with the hair fiber of the Angora goat,
the source of mohair. Angora rabbits are raised domestically. The fur is combed
and clipped from the rabbit every three months. Camel hair comes from the
Bactrian camel. The fiber is shed, and about 5 pounds (2.7 kilograms) is
produced per camel. The underhairs are used in textiles, and the coarse
outer guard hairs are used in paint brushes and other non-apparel uses.
3.
Cashmere is the soft hair fiber from the cashmere
(kashmir) goat. The fiber is harvested by combing the animal. A single goat
produces only about 4 ounces (114 grams) of fiber a year. Cashmere is considered
a luxury fiber.
Llama hair fibers are shorn from the animal once a year. They are similar to
alpaca fibers, but weaker.
4. Mohair is the long, straight, fine hair fiber from the Angora goat. The fiber is usually sheared from the animal twice a year.
5.
Vicuña is the hair fiber from a small non-domesticated
llama-like animal about the size of a dog. The animal lives at elevations above
16,000 feet in South America and has been
listed as endangered since 1969. Vicuña is the softest of the fleece fibers.
protein
based
Silk is a natural protein secreted by the larvae of several moth species.
The larvae use the filaments to construct a cocoon, from which the silk is
extracted. Twin filaments of the
protein fibroin are secreted and bound together in a single strand with the
protein gum sericin. During processing, the sericin is removed, leaving the
fibroin protein. Cultivated
or cultured silk is produced in very controlled conditions of environment and
diet. Tussah or wild silk is harvested from natural sources.