Afibre (also spelled asfiber ) is a piece of material which is long, thin and flexible, like a length ofthread . Plant fibres are the basis offabric such ascotton .Silk andwool fibres come from animals. In the 20th century many artificial fibres wereinvented likenylon andpolyester .
They are very important in the structure ofplants andanimals , because they holdtissues together.
There are many uses for fibres. They can bespun together intofilaments ,thread ,string orrope . They can bewoven infabric or incomposite materials
Natural fibers include those made byplants ,animals , and geological processes.[ 1]
Vegetable fibers are based on arrangements ofcellulose , often withlignin . Examples includecotton ,hemp ,jute ,flax ,abaca ,piña ,ramie ,sisal ,bagasse , andbanana . Plant fibers are used to makepaper andtextile (cloth). It is also used asdietary fiber .Wood fiber is fiber that gotten fromtrees . They includegroundwood ,lacebark ,thermomechanical pulp (TMP), and bleached or unbleachedkraft or sulfite pulps.Animal fibers mainly consist ofproteins . Examples aresilkworm silk ,spider silk ,sinew ,catgut ,wool ,sea silk andhair .Mineral fibers include theasbestos group. Asbestos is the only long mineral fiber that can be found innature . Six minerals have been classified as "asbestos". They includechrysotile ,amosite ,crocidolite ,tremolite ,anthophyllite andactinolite . Short, fiber-like minerals includewollastonite andpalygorskite .Biological fibers also known asfibrous proteins orprotein filaments consist of biologically important proteins,mutations or other genetic defects can lead to severediseases . For example, thecollagen family ofproteins ,tendon ,muscle proteins likeactin , cell proteins likemicrotubules and many others, spider silk, sinew and hair etc. Man-made are fibers that are changed by man. Man-made fibers consist of regenerated fibers and synthetic fibers.
Semi-synthetic fibers are made fromraw materials with natural long-chainpolymer structures . They are only changed and partiallydegraded by chemical processes. The first semi-synthetic fiber israyon . Most semi-synthetic fibers arecellulose regenerated fibers .[ 2]
Cellulose fibers are a type of man-made fibers, regenerated from naturalcellulose . The cellulose comes from many sources: rayon comes fromtree wood fiber ,bamboo fiber comes frombamboo ,seacell comes fromseaweed , etc.
Some examples of this type of fiber are:
Synthetic fibers come from synthetic materials such aspetrochemicals .
Metallic fibers can be gotten fromductile metals such ascopper ,gold orsilver andextruded ordeposited from more brittle ones, such asnickel ,aluminum oriron .
Carbon fibers are fibers that are mostly made up ofcarbon atoms . Carbon fibers are often based onoxidizing carbonizedpolymers throughpyrolysis likePAN .
Insilicon carbide fibers the basicpolymers are nothydrocarbons but polymers. About 50% of thecarbon atoms are replaced bysilicon atoms.
Fiberglass are also man-made fibers that come from natural raw materials. It is made from a specific typeglass , andoptical fiber , which is made from purified naturalquartz .
Polymer fibers are a type of man-made fibers, which are based on synthetic chemicals. These fibers are made from: 
