fiber

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1. A slender, elongated, threadlike object or structure.
2. Botany. One of the elongated, thick-walled cells that give strength and support to plant tissue.
3. Anatomy.
   1. Any of the filaments constituting the extracellular matrix of connective tissue.
   2. Any of various elongated cells or threadlike structures, especially a muscle fiber or a nerve fiber.
4. 1. A natural or synthetic filament, as of cotton or nylon, capable of being spun into yarn.
   2. Material made of such filaments.
5. 1. Something that provides substance or texture.
   2. Essential character: “stirred the deeper fibers of my nature” (Oscar Wilde).
   3. Basic strength or toughness; fortitude: lacking in moral fiber.
6. Coarse, indigestible plant matter, consisting primarily of polysaccharides such as cellulose, that when eaten stimulates intestinal peristalsis. Also called bulk, roughage.

[French fibre, from Old French, from Latin fibra.]

noun

1. A very fine continuous strand: fibril, filament, thread. See thing.
2. A distinctive, complex underlying pattern or structure: contexture, fabric, texture, warp and woof, web. See be.
3. Moral or ethical strength: character, honesty, integrity, principle. See strong/weak.

An elongated, threadlike structure of organic tissue.

Denis Burkitt (1911–1993), a British surgeon and medical researcher, is usually credited with popularizing the idea that dietary fiber may protect against the development of chronic diseases such as diabetes, hypercholesterolemia, heart disease, diverticular disease, and colon cancer that are prevalent in Western countries. Writing in the 1970s and 1980s, Burkitt described the relationship between large stools, which reflect a high intake of plant foods rich in dietary fiber, and a lack of "Western diseases," as he called them.

Dietary fiber is plant cell material that resists digestion by the endogenous enzymes of humans. It is not really an accurate term, as many of its components are not fibrous. Gums and mucilages, for example, are classified as dietary fiber because mammalian enzymes or secretions do not digest them. Only one component of dietary fiber, cellulose, is truly fibrous; yet "dietary fiber" is the accepted term for describing the roughage in the human diet.

Dietary fiber is found only in plant products, including fruits, vegetables, nuts, and grains. The most concentrated sources of dietary fiber are the bran layers of grains, such as wheat bran. Because of their higher water content, fruits and vegetables provide less dietary fiber per gram of ingested material than grains and cereals.

Recommendations for adult dietary fiber intake generally fall in the range of 20 to 35 grams per day. For children, the general rule is to add five to a child's age to determine the number of grams of fiber to be consumed daily. Thus, a ten-year-old child should consume 15 grams of dietary fiber a day. Usual intakes of dietary fiber in the United States average only 11 grams per day, so few people get the recommended amount. Most of the popular foods Americans consume contain little dietary fiber. For example, most servings of grains, fruits, and vegetables contain 1 to 3 grams of dietary fiber. Thus, to get the recommended amounts of dietary fiber one would need to consume at least ten servings of fiber-containing foods per day. Dietary fiber content of foods is listed on the Nutrition Facts panel on food packages. Foods particularly high in dietary fiber include bran cereals, which contain up to 13 grams of dietary fiber per serving, and beans and legumes, which contain more than 5 grams of dietary fiber per serving.

Several epidemiologic studies indicate that a high intake of dietary fiber protects against most chronic diseases. This is true even when confounding variables such as fat and calorie intake are accounted for. Dietary fiber may protect against large bowel cancer by enhancing the environment of the large intestine. Dietary fiber escapes digestion in the small intestine and is fermented in the large intestine by intestinal microflora. This fermentation yields short-chain fatty acids and gases. Short-chain fatty acids, including butyrate and propionate, have interesting physiological properties. Butyrate is a preferred gut fuel for the cells in the colon. Additionally, propionate may be involved in the cholesterol-lowering effects of certain dietary fiber. Dietary fiber fermentation may also enhance the number of beneficial microflora, such as bifidobacteria and lactobacillus. However, two recent large intervention studies did not find any protection in polyp prevention, which has led to questions about whether fiber should be recommended to prevent colon cancer (Goodlad, 2001).

Dietary fiber is an accepted therapy for gastrointestinal disorders such as constipation and diarrhea, and is often consumed as bulk laxatives or high-fiber breakfast cereals. Fiber may also protect against other cancers. International comparisons show an inverse correlation between breast cancer death rates and consumption of fiber-rich foods.

Dietary fiber has also been shown to be effective in reducing serum cholesterol, and it may decrease the risk of coronary heart disease by decreasing serum lipids, lowering blood pressure, improving glucose metabolism, and aiding in weight control. Soluble fibers appear to be the most effective in lowering serum cholesterol. The U.S. Food and Drug Administration (FDA) has accepted health claims for the cholesterol-lowering ability of oat bran and psyllium fiber. A significant reduction in serum cholesterol by soluble fiber was observed in sixty-eight of the seventy-seven human studies reviewed in a meta-analysis. Often, soluble fibers also decrease low-density lipoproteins (LDL) while maintaining high-density lipoproteins (HDL). Multiple mechanisms appear to be involved in the hypocholesterolemic response, and mechanisms for lowering cholesterol may vary considerably among the various sources of dietary fiber.

Some clinical research suggests that dietary fiber may also play a role in improving blood-sugar control in diabetes. Dietary fiber, especially soluble fiber, can delay glucose absorption and reduce insulin requirements in both insulin-dependent and non-insulin-dependent diabetes mellitus. Obese persons with diabetes often respond to a high-fiber diet with weight loss and decreased insulin requirements.

The best way to get dietary fiber in the diet is to consume a wide range of grains, legumes, fruits, and vegetables. Concentrated fiber sources such as bulk laxatives, fiber supplements, and foods fortified with fiber may be useful in the prevention and treatment of bowel disorders and as lipid-lowering therapies. Fiber supplements should be taken under medical supervision, since bowel obstructions, dehydration, and other medical contra-indicators have been reported with their use.

(SEE ALSO: Chronic Illness; Coronary Artery Disease; Foods and Diets; HDL Cholesterol; LDL Cholesterol; Nutrition)

Bibliography

Burkitt, D. P.; Walker, A. R.; and Painter, N. S. (1972). "Effect of Dietary Fiber on Stools and the Transit-Times, and its Role in the Causation of Disease." Lancet 2(7792):1408–1412.

Goodlad, R. A. (2001). "Dietary Fiber and Risk of Colorectal Cancer." GUT 48:587–589.

Schatzkin, A.; Lanza, E.; Corle, D.; Lance, P.; Cann, B.; Shike, M.; Weissfeld, J.; Burt, R.; Cooper, M. R.; Kikendall, J. W.; Cahill, J.; and the Polyp Prevention Trial Study Group (2000). "Lack of Effect of a Low-Fat, High-Fiber Diet on the Recurrence of Colorectal Adenomas." New England Journal of Medicine 342:1149–1155.

— JOANNE SLAVIN

Although Western tradition ranks clothing among the basic needs along with food and shelter, the members of some human societies in the recent past wore no clothing, and many societies today wear very little. Climate is not the deciding factor for nakedness, as societies known to use the least amount of clothing, the Fuegan and Tasmanian of 200 years ago, lived on islands with notoriously bad weather. In Europe, however, clothing is known from very early times. Small statues depict clothing as early as 15,000 bce. This clothing is thought to be of animal skins, but linen cloth made by weaving existed at least as early as 6000 bce. In any case, animal skins are not the right shape or size for clothing and need to be sewn together with fiber of some sort. While thin strips of skin have been used as fibers, the Ice Man of 3300 bce used animal sinews in some places and grass in others.

Although the earliest recorded evidence of the use of fiber involves flax -- linen is fiber from the flax plant -- ambiguous evidence suggests that wool from sheep or goats was employed for cloth by that time as well. Sheep and goats were among the first domesticated animals; in the New World, llamas and alpacas, which also produce wool, were also domesticated early.

In warmer climates of both the Old and New worlds, cotton became the most common plant fiber from early times. By the 18th century ce, cotton was shipped all over the world. Introduction of new ways of processing cotton was a hallmark of the Industrial Revolution.

Humans are not the only animals to use fiber. Birds have long used animal hair and plant fibers for nest building. They also anticipated humans in the discovery of the utility of silk, a chemical fiber produced by spiders and caterpillars. Most birds prefer spider silk, some of which forms a micro-Velcro and some of which has adhesives attached. People in China discovered that the caterpillar of the silkworm moth produces the longest silk fibers in nature, some 900 m (3000 ft) long. Shiny silk was seen from the first as superior to animal hair or plant fibers. During the Chinese's virtual monopoly of hundreds of years, trade in silk became the strand that held eastern Asia to the West along the famous Silk Road.

Silk begins as a liquid that is extruded though a tiny opening; it hardens into a solid in the air. As early as the 17th century, inventors recognized that this process could be imitated by a machine if the right liquid were found. Some early attempts used gums or other natural plant products. Chemists in the 19th century perceived that cellulose from the breakdown of wood or some variation on it would do the trick. At least a half dozen different versions of such artificial silks emerged, the best of which we now call rayon. In the 20th century, the same idea was used with a different class of chemicals, the polymers. In bulk, the polymers are plastics, but as fibers they are nylon, Dacron, and polyester. For many purposes, the artificial fibers are better (wrinkle-free cloth is often cited as the greatest boon), but natural fibers continue to excel for others.

One of the elongated, thick-walled cells that give strength and support to plant tissue.

For other uses, see Fiber (disambiguation).

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Fiber, also spelled fibre, is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread. They are very important in the biology of both plants and animals, for holding tissues together. Human uses for fibers are diverse. They can be spun into filaments, string or rope, used as a component of composite materials, or matted into sheets to make products such as paper or felt. Fibers are often used in the manufacture of other materials. Synthetic fibers can be produced very cheaply and in large amounts compared to natural fibers, but natural fibers enjoy some benefits, such as comfort, over their man-made counterparts.

Contents 1 Natural fibers 2 Human-made fibers 2.1 Cellulose fibers 2.2 Mineral fibers 2.3 Polymer fibers 2.4 Microfibers 3 See also 4 References

Natural fibers

Main article: Natural fiber

Natural fibers include those produced by plants, animals, and geological processes. They are biodegradable over time. They can be classified according to their origin:

• Vegetable fibers are generally based on arrangements of cellulose, often with lignin: examples include cotton, hemp, jute, flax, ramie, and sisal. Plant fibers are employed in the manufacture of paper and textile (cloth), and dietary fiber is an important component of human nutrition.
• Wood fiber, distinguished from vegetable fiber, is from tree sources. Forms include groundwood, thermomechanical pulp (TMP) and bleached or unbleached kraft or sulfite pulps. Kraft and sulfite, also called sulphite, refer to the type of pulping process used to remove the lignin bonding the original wood structure, thus freeing the fibers for use in paper and engineered wood products such as fiberboard.
• Animal fibers consist largely of particular proteins. Instances are spider silk, sinew, catgut, wool and hair such as cashmere, mohair and angora, fur such as sheepskin, rabbit, mink, fox, beaver, etc.
• Mineral fibers comprise asbestos. Asbestos is the only naturally occurring long mineral fiber. Short, fiber-like minerals include wollastonite, attapulgite and halloysite.

Human-made fibers

Synthetic or man-made fibers generally come from synthetic materials such as petrochemicals. But some types of synthetic fibers are manufactured from natural cellulose, including rayon, modal, and the more recently developed Lyocell. Cellulose-based fibers are of two types, regenerated or pure cellulose such as from the cupro-ammonium process and modified cellulose such as the cellulose acetates.

Fiber classification in reinforced plastics falls into two classes: (i) short fibers, also known as discontinuous fibers, with a general aspect ratio (defined as the ratio of fiber length to diameter) between 20 to 60, and (ii) long fibers, also known as continuous fibers, the general aspect ratio is between 200 to 500^[1].

Cellulose fibers

• Cellulose fibers are a subset of man-mad fibers, regenerated from natural cellulose. The cellulose comes from various sources. Modal is made from beech trees, bamboo fiber is a cellulose fiber made from bamboo, soy silk is made from soybeans, seacell is made from seaweed, etc.

Mineral fibers

• Fiberglass, made from specific glass, and optical fiber, made from purified natural quartz, are also man-made fibers that come from natural raw materials.
• Metallic fibers can be drawn from ductile metals such as copper, gold or silver and extruded or deposited from more brittle ones, such as nickel, aluminum or iron.
• Carbon fibers are often based on carbonised polymers, but the end product is pure carbon.

Polymer fibers

• Polymer fibers are a subset of man-made fibers, which are based on synthetic chemicals (often from petrochemical sources) rather than arising from natural materials by a purely physical process. These fibers are made from:
  • polyamide nylon,
  • PET or PBT polyester
  • phenol-formaldehyde (PF)
  • polyvinyl alcohol fiber (PVA)
  • polyvinyl chloride fiber (PVC)
  • polyolefins (PP and PE)
  • acrylic polyesters, pure polyester PAN fibers are used to make carbon fiber by roasting them in a low oxygen environment. Traditional acrylic fiber is used more often as a synthetic replacement for wool. Carbon fibers and PF fibers are noted as two resin-based fibers that are not thermoplastic, most others can be melted.
  • Aromatic polyamids (aramids) such as Twaron, Kevlar and Nomex thermally degrade at high temperatures and do not melt. These fibers have strong bonding between polymer chains
  • polyethylene (PE), eventually with extremely long chains / HMPE (e.g. Dyneema or Spectra).
  • Elastomers can even be used, e.g. spandex although urethane fibers are starting to replace spandex technology.
  • polyurethane fiber

• Coextruded fibers have two distinct polymers forming the fiber, usually as a core-sheath or side-by-side. Coated fibers exist such as nickel-coated to provide static elimination, silver-coated to provide anti-bacterial properties and aluminum-coated to provide RF deflection for radar chaff. Radar chaff is actually a spool of continuous glass tow that has been aluminum coated. An aircraft-mounted high speed cutter chops it up as it spews from a moving aircraft to confuse radar signals.

Microfibers

Micro fibers in textiles refer to sub-denier fiber (such as polyester drawn to 0.5 dn). Denier and Detex are two measurements of fiber yield based on weight and length. If the fiber density is known you also have a fiber diameter, otherwise it is simpler to measure diameters in micrometers. Microfibers in technical fibers refer to ultra fine fibers (glass or meltblown thermoplastics) often used in filtration. Newer fiber designs include extruding fiber that splits into multiple finer fibers. Most synthetic fibers are round in cross-section, but special designs can be hollow, oval, star-shaped or trilobal. The latter design provides more optically reflective properties. Synthetic textile fibers are often crimped to provide bulk in a woven, non woven or knitted structure. Fiber surfaces can also be dull or bright. Dull surfaces reflect more light while bright tends to transmit light and make the fiber more transparent.

Very short and/or irregular fibers have been called fibrils. Natural cellulose, such as cotton or bleached kraft, show smaller fibrils jutting out and away from the main fiber structure.

See also

• Optical fiber
• Fiber crop
• Tensile strength
• Molded pulp
• Dietary fiber
• Fibers in Differential Geometry
• International Year of Natural Fibres

References

1. ^ Serope Kalpakjian, Steven R Schmid. "Manufacturing Engineering and Technology". International edition. 4th Ed. Prentice Hall, Inc. 2001. ISBN 0-13-017440-8.

v • d • e Fibers Natural Animal Alpaca · Angora · Camel hair · Cashmere · Catgut · Chiengora · Llama · Mohair · Rabbit · Silk · Sinew · Spider silk · Wool · Yak Vegetable Abacá · Bamboo · Coir · Cotton · Flax · Hemp · Jute · Kenaf · Piña · Raffia · Ramie · Sisal · Wood Mineral Asbestos · Basalt · Mineral wool · Glass wool Cellulose Acetate · Art silk · Bamboo · Lyocell · Modal · Rayon · Tencel Synthetic Acrylic · Aramid (Twaron · Kevlar · Technora · Nomex) · Carbon (Tenax) · Microfiber · Modacrylic · Nylon · Olefin · Polyester · Polyethylene (Dyneema · Spectra) · Spandex · Vinalon · Zylon

v • d • e Textile arts Fundamentals: Applique · Crochet · Dyeing · Embroidery · Fabric (textiles) · Felting · Fiber · Knitting · Lace · Nålebinding · Needlework · Patchwork · Passementerie · Plying · Quilting · Rope · Sewing · Spinning · Tapestry · Textile printing · Weaving · Yarn History of... : Clothing and textiles · Silk · Quilting · Textiles in the Industrial Revolution · Timeline of textile technology Related: Blocking · Fiber art · Mathematics and fiber arts · Manufacturing · Preservation · Terminology · Textile industry · Textile Museums  · Wearable fiber art

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Dansk (Danish)
n. - fiber, trævl, støbning

idioms:

• fibre optics    fiberoptik
• with every fibre of your being    med sjæl og legeme

Nederlands (Dutch)
vezel, axon/dendriet (uitlopers van zenuwcel), kracht/kwaliteit, kenmerkende structuur, vezelachtige structuur, karakter

Français (French)
n. - fibre, (Tex) fibre, fibres, cellulose végétale, (Bot) fibre, (Physiol) fibre, (fig) courage

idioms:

• fibre optics    fibres optiques
• with every fibre of one's being    de tout son être

Deutsch (German)
n. - Faser, Faserstoff, Charakter

idioms:

• fibre optics    Faseroptik
• with every fibre of one's being    sehr intensiv

Ελληνική (Greek)
n. - ίνα, νημάτιο, (μτφ.) ιδιοσυστασία, χαρακτήρας

idioms:

• fibre optics    οπτικές ίνες
• with every fibre of your being    με κάθε ίνα της ύπαρξής σου

Italiano (Italian)
fibra

idioms:

• fibre optics    fibre ottiche
• with every fibre of your being    con tutte le tue forze

Português (Portuguese)
n. - fibra (f)

idioms:

• fibre optics    fibra (f) ótica
• with every fibre of your being    profundamente

Русский (Russian)
волокно, склад характера, устойчивость, грубая пища

idioms:

• fibre optics    волоконная оптика
• with every fibre of your being    всеми фибрами души

Español (Spanish)
n. - fibra, filamento

idioms:

• fibre optics    fibra óptica
• with every fibre of one's being    con toda el alma

Svenska (Swedish)
n. - fiber, fibermassa, rottråd, struktur, natur (bildl.)

中文（简体）(Chinese (Simplified))
纤维, 纤维制品, 构造

idioms:

• fibre optics    纤维光学
• with every fibre of your being    竭尽全力

中文（繁體）(Chinese (Traditional))
n. - 纖維, 纖維製品, 構造

idioms:

• fibre optics    纖維光學
• with every fibre of your being    竭盡全力

한국어 (Korean)
n. - 섬유, 성격, 강도

idioms:

• with every fibre of your being    학문적으로 유용한

日本語 (Japanese)
n. - 繊維, 繊維製品, 繊維質, 性質, 素質, ひげ根, 強み

idioms:

• fibre optics    繊維光学

العربيه (Arabic)
‏(الاسم) ليف , نسيج‏

עברית (Hebrew)
n. - ‮סיב, אופי, מבנה, חוט, ליף‬

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