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Fiber Plants. Vascular Cells. Cellulose Fibers. Plant Fibers. The cell wall of the fiber cells – which is what gives them their properties of strength and elasticity – are mostly cellulose, although there may also be lignin, tannins, gums, pectins and other polysaccharides present
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Plant Fibers • The cell wall of the fiber cells – which is what gives them their properties of strength and elasticity – are mostly cellulose, although there may also be lignin, tannins, gums, pectins and other polysaccharides present • The most valuable fibers (for human use) are those that are nearly pure cellulose and white – cellulose is an extremely strong material, with tensile strength (resistance to tearing) that is equal to that of steel – fibers with much lignin are usually of poorer quality and are typical not as strong and more brown in color
Classifying Fibers • Fibers can be classified according to their use – • Fibers used to make cloth are textile fibers • Fibers to make rope are cordage fibers • Fibers used as stuffing are filling fibers • Natural fibers are made of plant or animal materials – mineral fibers are made from things like asbestos • Animal fibers like wool or silk are mostly protein while plant fibers are mostly cellulose • Some synthetic fibers are made up from natural materials – rayon is made from cellulose wood pulp
Classifying Fiber II • Plant fibers can also be classified by where they occur on the plant – • Surface fibers are found on the outer layers of leaves, seeds or fruits – cotton is made from seed hairs covering the surface of cotton seeds • Bast or soft fibers are clusters of phloem fibers found in the inner bark of some dicot stems – linen and ramie are both bast fibers • Hard fibers or leaf fibers are produced from the vascular bundles or veins in leaves – they are usually made up of both xylem and phloem and surrounding sheath fibers and cells – these usually come from monocot leaves – sisal and Manila hemp are examples • Hard fibers usually have a higher lignin content than soft fibers
Early History of Cotton Use • Cotton was one of the first fiber plants to be domesticated by humans – its use originated in two different parts of the world with at least 4 different species being regularly used • Cotton was harvested from the wild in coastal areas of Peru about 10,000 YA and was domesticated there by 4500 YA – from there its use spread and it was grown and used by native peoples in the American Southwest • In the Old World cotton cloth has been dated back 5000 YA – it was first grown on the Indian subcontinent and its use spread westward to Assyria, Babylonia, Persia (modern day Iraq and Iran) and then to Greece and Rome (although Greeks and Romans preferred to use linen)
More Cotton History • Cotton was especially well developed by Muslim peoples in the Near East in the 9th and 10th Centuries and the term muslin for a fine cotton cloth reflects that history • Old World cotton was introduced to Florida in 1556 and it was grown in Virginia beginning in 1607 – within 100 years, cotton was the most important crop in the southern American colonies • Cotton was at first a minor source of cloth in Europe until the 18th century when Peruvian varieties were introduced – they had longer seed hairs which allowed for better spinning into cloth • Major cotton producing countries are China, US, India, Pakistan, former Soviet nations
Cotton Species • The old world cottons are diploid species that produce short fibers – G. herbaceum appears to have come from southern Africa and gave rise to G. arboretum in India; • The new world cottons are tetraploids that produce long fibers – they may have arisen as a cross between G. herbaceum and G. raimondii from Peru - how herbaceum got to Peru is not clear • G. hirsutum is the mostly commonly grown cotton in the world – it is often known as upland cotton and probably arose in Central America or Mexico; G. barbedense originated in the Andes of Peru and is the oldest used form of cotton
History of Flax Use • Linen may be the oldest fabric made from plant fibers – Linen is made from flax Linum usitatissimum – the stem fibers of flax, an annual plant, have been made to make fabric for at least 10,000 years – flax fibers have been found at sites of Swiss lake dwellers • Flax was also used in Mesopotamia, Assyria, and Babylonia • Egypt developed a very extensive and sophisticated use of flax – Egyptian linens dating back to 6500 YA have been found – Egyptians used linen for clothing for priests and royalty, to wrap mummies and exported to other countries for use in making sails
More Flax History • Ancient Greeks and Romans grew some flax • There is even evidence of use of flax in prehistoric American Southwest • Flanders (part of Belgium) became a major European center for growing flax, Ireland was also a center for flax growing • Today linen is used for only about 2% of the world’s textiles
Flax Cultivation • Two types of flax are grown – one for its seed oil (linseed oil) and one for fibers – flax for fiber is unbranched and grows to about 1 m tall • Flax is a soft bast fiber composed of phloem cell bundles – each flax stem typically contains about 15-40 fiber bundles – • Fibers are preserved by pulling the plants up by the roots either by hand or with a special machine • Flax is gathered into bundles, left in the field to dry
Preparing Linen Fibers • Linen is prepared by retting the stems – allowing microbes to ferment on them – this can be done by letting the stems sit in dewy conditions (4 to 6 weeks), putting them in ponds (about 2 weeks) or in tanks of warm water (a few days) • Retted fibers are dried and then broken (pounded) to free the fiber from the stem • Flax is then often bleached in the sun or by chemicals
History of Hemp Fabric • Hemp has long been a traditional source for fiber for rope and clothing and even for paper • Hemp fibers were used to make fabric as long ago as 8000 BCE - the fibers are so strong that hemp was woven to make ship’s sails from the 5th century BCE until the mid-19th century • Hemp was the major source of fiber for paper until 1883, when wood pulp replaced it
More Hemp History • Hemp paper was used to produce Bibles from the first Gutenberg Bible to the King James Bible • Thomas Jefferson grew hemp for fiber; Thomas Paine’s pamphlets were printed on paper made from hemp fiber; the first and second drafts of the Declaration of Independence were written on hemp paper imported from Holland • Hemp was commonly used to make cordage, lighting oil, building materials, and now even plastic pipe has been made from hemp • During WW2, many farmers in the Midwest grew hemp for fiber for ropes (cordage)
