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Fiber

"Fibre" redirects here. For other uses, see Fiber (disambiguation).
Not to be confused with Dietary fiber.

A bundle of optical fibers
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Fiber
Natural fibers
Animal
Plant
Mineral
Human-made fibers
Regenerated fibers
Semi-synthetic fibers
Synthetic fibers

Fiber (also spelled fibre in British English; from Latin: fibra)[1] is a natural or artificial substance that is significantly longer than it is wide.[2] Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorporate fibers, for example carbon fiber and ultra-high-molecular-weight polyethylene.

Synthetic fibers can often be produced very cheaply and in large amounts compared to natural fibers, but for clothing natural fibers have some benefits, such as comfort, over their synthetic counterparts.

Natural fibers

Main article: Natural fiber

Natural fibers develop or occur in the fiber shape, and include those produced by plants, animals, and geological processes.[2] They can be classified according to their origin:

Artificial fibers

Artificial or chemical fibers are fibers whose chemical composition, structure, and properties are significantly modified during the manufacturing process. In fashion, a fiber is a long and thin strand or thread of material that can be knit or woven into a fabric.[4] Artificial fibers consist of regenerated fibers and synthetic fibers.

See also: fiber modification

Semi-synthetic fibers

Semi-synthetic fibers are made from raw materials with naturally long-chain polymer structure and are only modified and partially degraded by chemical processes, in contrast to completely synthetic fibers such as nylon (polyamide) or dacron (polyester), which the chemist synthesizes from low-molecular weight compounds by polymerization (chain-building) reactions. The earliest semi-synthetic fiber is the cellulose regenerated fiber, rayon.[5] Most semi-synthetic fibers are cellulose regenerated fibers.

Cellulose regenerated fibers

Cellulose fibers are a subset of artificial fibers, regenerated from natural cellulose. The cellulose comes from various sources: rayon from tree wood fiber, bamboo fiber from bamboo, seacell from seaweed, etc. In the production of these fibers, the cellulose is reduced to a fairly pure form as a viscous mass and formed into fibers by extrusion through spinnerets. Therefore, the manufacturing process leaves few characteristics distinctive of the natural source material in the finished products.

Some examples of this fiber type are:

Historically, cellulose diacetate and -triacetate were classified under the term rayon, but are now considered distinct materials.

Synthetic fibers

Main article: Synthetic fiber

Synthetic come entirely from synthetic materials such as petrochemicals, unlike those artificial fibers derived from such natural substances as cellulose or protein.[6]

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 and 60, and (ii) long fibers, also known as continuous fibers, the general aspect ratio is between 200 and 500.[7]

Metallic fibers

Main article: Metallic fiber

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 fiber

Carbon fibers are often based on oxidized and via pyrolysis carbonized polymers like PAN, but the end product is almost pure carbon.

Silicon carbide fiber

Silicon carbide fibers, where the basic polymers are not hydrocarbons but polymers, where about 50% of the carbon atoms are replaced by silicon atoms, so-called poly-carbo-silanes. The pyrolysis yields an amorphous silicon carbide, including mostly other elements like oxygen, titanium, or aluminium, but with mechanical properties very similar to those of carbon fibers.

Fiberglass

See also: Glass § Fibreglass

Fiberglass, made from specific glass, and optical fiber, made from purified natural quartz, are also artificial fibers that come from natural raw materials, silica fiber, made from sodium silicate (water glass) and basalt fiber made from melted basalt.

Mineral fibers

Mineral fibers can be particularly strong because they are formed with a low number of surface defects; asbestos is a common one.[8]

Polymer fibers

  • Polymer fibers are a subset of artificial 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:
  • 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

Invented in Japan in the early 1980s, microfibers are also known as microdenier fibers. Acrylic, nylon, polyester, lyocell and rayon can be produced as microfibers. In 1986, Hoechst A.G. of Germany produced microfiber in Europe. This fiber made it way into the United States in 1990 by DuPont.[9]

Microfibers in textiles refer to sub-denier fiber (such as polyester drawn to 0.5 denier). Denier and Dtex 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.[10]

Typical properties of selected fibers

Fibers can be divided into natural and artificial (synthetic) substance, their properties can affect their performance in many applications. Synthetic fiber materials are increasingly replacing other conventional materials like glass and wood in a number of applications.[11] This is because artificial fibers can be engineered chemically, physically, and mechanically to suit particular technical engineering.[12] In choosing a fiber type, a manufacturer would balance their properties with the technical requirements of the applications. Various fibers are available to select for manufacturing. Here are typical properties of the sample natural fibers as compared to the properties of artificial fibers.

Table 1. Typical Properties of Selected Natural Fibers[13][14]
Fiber type Fiber Diameter

(in)

Specific Gravity Tensile Strength

(Ksi)

Elastic Modulus

(Ksi)

Elongation at Break

(%)

Water Absorption

(%)

Wood Fiber

(Kraft Pulp)

0.001-0.003 1.5 51-290 1500-5800 N/A 50-75
Musamba N/A N/A 12 130 9.7 N/A
Coconut 0.004-0.016 1.12-1.15 17.4-29 2750-3770 10-25 130-180
Sisal 0.008-0.016[15] 1.45[15] 40-82.4 1880-3770 3-5 60-70
Sugar Cane Bagasse 0.008-0.016 1.2-1.3 26.7-42 2175-2750 1.1[16] 70-75
Bamboo 0.002-0.016 1.5 50.8-72.5 4780-5800 N/A 40-45
Jute 0.004-0.008 1.02-1.04 36.3-50.8 3770-4640 1.5-1.9 28.64[17]
Elephant grass 0.003-0.016[18] 0.818[18] 25.8 710 3.6 N/Ab
a  Adapted from ACI 544. IR-96 P58, reference [12] P240 and [13]

b  N/A means properties not readily available or not applicable


Table 2. Properties of Selected Artificial Fibers
Fiber type Fiber Diameter

(0.001 in)

Specific Gravity Tensile Strength (Ksi) Elasticity Modulus  

(Ksi)

Elongation at Break

(%)

Water Absorption

(%)

Melting Point

(°C)

Maximum Working

Temp (°C)

Steel 4-40 7.8 70-380 30,000 0.5-3.5 nil 1370[19] 760[19]
Glass 0.3-0.8 2.5 220-580 10,400-11,600 2-4 N/A 1300 1000
Carbon 0.3-0.35 0.90 260-380 33,400-55,100 0.5-1.5 nil 3652-3697[20] N/A
Nylon 0.9 1.14 140 750 20-30 2.8-5.0 220-265 199
Acrylics 0.2-0.7 1.14-1.18 39-145 2,500-2,800 20-40 1.0-2.5 Decomp 180
Aramid 0.4-0.5 1.38-1.45 300-450 9,000-17,000 2-12 1.2-4.3 Decomp 450
Polyester 0.4-3.0 1.38 40-170 2,500 8-30 0.4 260 170
Polypropylene 0.8-8.0 0.9 65-100 500-750 10-20 nil 165 100
Polyethylene

   Low

   High

1.0-40.0

0.92

0.95

11-17

50-71

725

25-50

20-30

nil

nil

110

135

55

65

a  Adapted from ACI 544. IR-96 P40, reference [12] P240, [11] P209 and [13]

b  N/A means properties not readily available or not applicable

The tables above just show typical properties of fibers, in fact there are more properties which could be referred as follows (from a to z):[14]

Arc Resistance, Biodegradable, Coefficient of Linear Thermal Expansion, Continuous Service Temperature, Density of Plastics, Ductile / Brittle Transition Temperature, Elongation at Break, Elongation at Yield, Fire Resistance, Flexibility, Gamma Radiation Resistance, Gloss, Glass Transition Temperature, Hardness, Heat Deflection Temperature, Shrinkage, Stiffness, Ultimate tensile strength, Thermal Insulation, Toughness, Transparency, UV Light Resistance, Volume Resistivity, Water absorption, Young's Modulus

See also

References

  1. ^ Harper, Douglas. "fiber". Online Etymology Dictionary.
  2. ^ a b Kadolph, Sara (2002). Textiles. Prentice Hall. ISBN 978-0-13-025443-6.
  3. ^ Saad, Mohamed (Oct 1994). Low resolution structure and packing investigations of collagen crystalline domains in tendon using Synchrotron Radiation X-rays, Structure factors determination, evaluation of Isomorphous Replacement methods and other modeling. PhD Thesis, Université Joseph Fourier Grenoble I. pp. 1–221. doi:10.13140/2.1.4776.7844.
  4. ^ "man-made fibre". Encyclopædia Britannica. Encyclopædia Britannica, Inc. 2013.
  5. ^ Kauffman, George B. (1993). "Rayon: the first semi-synthetic fiber product". Journal of Chemical Education. 70 (11): 887. Bibcode:1993JChEd..70..887K. doi:10.1021/ed070p887.
  6. ^ "synthetic fibre". Encyclopædia Britannica. Encyclopædia Britannica, Inc. 2013.
  7. ^ Serope Kalpakjian, Steven R Schmid. "Manufacturing Engineering and Technology". International edition. 4th Ed. Prentice Hall, Inc. 2001. ISBN 0-13-017440-8.
  8. ^ James Edward Gordon; Philip Ball (2006). The new science of strong materials, or, Why you don't fall through the floor. Princeton University Press. ISBN 978-0-691-12548-0. Retrieved 28 October 2011.
  9. ^ Cohen, Allen (11 November 2011). J. J. Pizzuto's Fabric Science (10th ed.). Fairchild Books. p. 51. ISBN 978-1-60901-380-6.
  10. ^ Hans-J. Koslowski. "Man-Made Fibers Dictionary". Second edition. Deutscher Fachverlag. 2009 ISBN 3-86641-163-4
  11. ^ Shenoy, Aroon (1999). Rheology of Filled Polymer Systems. Kluwer Academic Publishers. ISBN 978-0-412-83100-3.
  12. ^ Hollaway, C. (1990). Polymers and Polymer Composites in Construction. Great Britain: Bulter and Tanner Ltd. p. 209. ISBN 978-0-7277-1521-0.
  13. ^ Design and Control of Concrete Mixtures". Sixteenth Edition. United States of America: Portland Cement Association. 2018. pp. 237–247. ISBN 978-0-89312-277-5.
  14. ^ a b "Polymer Properties – Omexus by Special Chem".
  15. ^ a b "Sisal Fiber – World of Sisal".
  16. ^ Sain, M. (2014). "The use of sugarcane bagasse fibres as reinforcements in composites". In Faruk, Omar; Sain, Mohini (eds.). Biofiber Reinforcements in Composite Materials. Elsevier Science & Technology. ISBN 9781782421221.
  17. ^ Narayanan, Venkateshwaran (2012). "Mechanical and Water Absorption Properties of Woven Jute/Banana Hybrid Composites". Fibers and Polymers. 13 (7, 907–914): 907–914. doi:10.1007/s12221-012-0907-0.
  18. ^ a b K. Murali Mohan, Rao (2007). "Tensile Properties of Elephant grass fiber reinforced polymer Composites". Journal of Materials Science. 42 (9, 3266–3272): 3266–3272. doi:10.1007/s10853-006-0657-8.
  19. ^ a b "Metallic Materials – TEADIT" (PDF).
  20. ^ "Carbon Fiber – Americans Elements".
Quelle: http://en.wikipedia.org/wiki/Mineral_fiber