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Page: Man-made Fibers
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Man-made fibers may come from natural raw materials or from synthetic chemicals. Many types of fiber 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 or derivitized cellulose such as the cellulose acetates.
Mineral fibers
The most well-known mineral fibers are glass and metal fibers.
* Fiberglass made from specific glass formulas 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. Such fibers are made from:
o polyamide nylon,
o PET or PBT polyester
o phenol-formaldehyde (PF)
o polyvinyl alcohol fiber (PVOH)
o polyvinyl chloride fiber (PVC)
o polyolefins (PP and PE)
o acrylic polymers, pure polyacrylonitrile 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.
o Aromatic polyamids such as Twaron, Kevlar and Nomex thermally degrade at high temperatures and do not melt. These fibers have strong bonding between polymer chains
o polyethylene (PE), eventually with extremely long chains / HMPE (e.g. Dyneema or Spectra).
o Elastomers can even be used, e.g. spandex although urethane fibers are starting to replace spandex technology.
o 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 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 foil 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 micrometres. Microfibers in technical fibers refer to ultrafine 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, nonwoven 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.
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Important notice:
The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other
qualified health provider with any questions you may have regarding a medical condition.
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