A natural or manmade substance that is substantially longer than it is wide is known as fibre (from the Latin word fibra. Fibres are frequently utilised to create other materials. Fibres are frequently used in the strongest engineering materials, such as carbon fibre and ultra-high-molecular-weight polyethylene.
Natural fibres can sometimes be manufactured more cheaply and in greater quantities than synthetic fibres, however for clothing, natural fibres have several advantages over synthetic ones, such as comfort.
Generally speaking, fibres are long, thin, flexible structures that resemble threads. Both plants and animals are the two main suppliers of fibre. The best fabrics are then woven from the obtained yarns and spun fibres. A single long fibre can be used to create yarn for several sorts of fabrics.Natural fibers
Classification of fibres
The two types of fibres are natural and man-made, depending on where they come from.
1) Natural fibres
A natural fibre can be categorised based on where it came from. Among the significant fibres in the vegetable, or cellulose-base, class are jute, flax, and cotton. Wool, mohair, and silk are examples of fibres made mostly from animal protein. Asbestos is a significant mineral fibre, as is sisal.
Natural fibres, which include those created by plants, animals, and geological processes, emerge or appear in the fibre shape. They can be grouped according to their origins:
- Arrangements of cellulose, frequently combined with lignin, are the basis of most vegetable fibres. Cotton, hemp, jute, flax, abaca, pia, ramie, sisal, bagasse, and banana are among examples. Dietary fibre is a crucial part of human nutrition and is used to make paper and textile (clothing) from plants.
- Wood fibre comes from tree sources, as opposed to vegetable fibre. Groundwood, lacebark, thermomechanical pulp (TMP), bleached or unbleached kraft, and sulfite pulps are some examples of forms. The terms “kraft” and “sulfite” refer to different pulping techniques that release the fibres for use in paper and engineered wood products like fiberboard by removing the lignin that was holding the original wood structure together.
- Particular proteins make up the majority of animal fibres. Examples include fur made from sheepskin, rabbit, mink, fox, beaver, and other animals, as well as silk made from silkworms, spiders, sinew, catgut, wool, and sea silk.
- A collection of mineral fibres is asbestos. The only naturally occurring long mineral fibre is asbestos. Chrysotile from the serpentine class and the amphibole class’s amosite, crocidolite, tremolite, anthophyllite, and actinolite have all been designated as “asbestos” minerals. Wollastonite and palygorskite are minerals that are short and resemble fibre.
- The majority of biological fibres, often referred to as fibrous proteins or protein filaments, are composed of biologically significant and relevant proteins, in which mutations or other genetic flaws can cause serious disorders. A few examples are the collagen family of proteins, tendons, actin, a protein found in muscles, microtubules, and several other substances like hair, sinew, and spider silk.
2) Artificial fibers
Fibres that have undergone considerable chemical composition, structural, and physical property changes throughout the manufacturing process are known as artificial or chemical fibres.
A fibre is a long, thin strand of fabric that can be knitted or woven into a cloth in the world of fashion. Regenerated fibres and synthetic fibres make up artificial fibres.
a) Semi-synthetic fibers
Semi-synthetic fibres are made from raw materials with naturally long-chain polymer structures and are only modified and partially degraded by chemical processes, as opposed to fully synthetic fibres like nylon (polyamide) or dacron (polyester), which the chemist synthesises from low-molecular weight compounds through polymerization (chain-building) reactions. The rayon made from cellulose regeneration is the first semi-synthetic fibre. The majority of semi-synthetic fibres are made from recycled cellulose.
b) Cellulose regenerated fibers
A subset of synthetic fibres made from naturally occurring cellulose are called cellulose fibres. The cellulose is derived from a variety of sources, including bamboo fibre, seacell, rayon, and seaweed. To create these fibres, cellulose is converted to a relatively pure form as a viscous substance, which is then extruded through spinnerets to create fibres. As a result, the manufacturing process does not leave many traits that make the completed items stand out from the original source material.
Examples of this type of fibre include:
Rayon
A natural source of regenerated cellulose, such as wood and other associated agricultural products, is used to create rayon, a semi-synthetic fibre. Its molecules resemble those of cellulose. Viscose is another name for it. There are many different types and grades of viscose fibres and films. Some mimic the appearance and feel of organic materials including silk, wool, cotton, and linen. Artificial silk is a common name for the materials that imitate silk.
Textiles for clothes and other uses are created using the fibre. In order to transform the fibres into the desired shape, cellulose must be solubilized during rayon manufacturing. The cuprammonium process, which uses ammoniacal solutions of copper salts to solubilize, is no longer in use. The viscose process, which is currently the most popular, uses alkali and carbon disulfide. The Lyocell process, on the other hand, uses amine oxide. The final option is more expensive but avoids the neurotoxic carbon disulfide of the viscose process.
Rayon and its variants
Cellulose is first dissolved, and then this solution is changed back into fibre insoluble cellulose to create rayon. Numerous techniques have been developed for this regeneration. The three most common methods for producing rayon are the cuprammonium, viscose, and lyocell processes. The first two techniques have been used successfully for over a century.
Lyocell
A semi-synthetic fibre called Lyocell is used to create textiles for garments and other uses.It is a type of regenerate cellulose created through pulp dissolution and dry jet-wet spinning . Contrary to other of the more popular viscose processes, the production of rayon using Lyocell does not include the use of carbon disulfide, which is hazardous to both the environment and employees. Tencel was the first trademark for Lyocell in 1982.
The trademark “Lyocell” is now used to refer to the Lyocell method of producing cellulose fibres as a generic term. “A fibre composed of cellulose precipitated from an organic solution in which no substitution of the hydroxy groups takes place, and no chemical intermediates are formed,” according to the U.S. Federal Trade Commission, is what Lyocell is. The fibre is categorised as a subcategory of rayon.
Names
Lenzing Lyocell (Lenzing), Newcell (Akzo Nobel), and Seacell (Zimmer AG) are other brand names for Lyocell fibres. It is also offered under the Excel brand by the business Birla.
Lyocell method
The N-methyl morpholine N-oxide (NMMO) solvent is used in the lyocell process to dissolve various cellulose products. Because the lyocell method is more expensive than the viscose process, it is not frequently employed.
Cellulose is the first step in the procedure, which comprises dry jet-wet spinning. It was created by Courtaulds Fibres and the now-defunct American Enka Company. One lyocell fibre is Tencel from Lenzing. The lycocell process does not involve very poisonous carbon sulphide, in contrast to the viscose process. The trademark “Lyocell” is now used to refer to the lyocell method of producing cellulose fibres as a generic term.
Related materials
Esters of cellulose rather than regenerated cellulose are comparable compounds.
- Nitrocellulose
A cellulose derivative that is soluble in organic solvents is nitrocellulose. It mostly functions as an explosive or lacquer. Nitrocellulose was used to create a variety of early polymers, including celluloid.
- Acetate
Previously regarded as the same fabric, viscose rayon and cellulose acetate have several characteristics in common. Acetate is prone to melting, whereas rayon is heat-resistant. Clothing made of acetate melts when heated in a tumble dryer, therefore it must be carefully washed by hand or dry cleaned. The two textiles must now be listed separately on clothing labels.
- Cellophane
In most cases, cellophane is produced using the viscose method, but is dried into sheets rather than fibres.
Cellulose diacetate
Cellulose is treated with acetic acid to create cellulose diacetate, often known as diacetate, a synthetic polymer. Each unit of D-anhydroglucopyranose on the cellulose molecule has two acetyl functional groups. The United States is where it was initially created.
Its cellulose foundation makes it brittle. Vinegar syndrome is caused by the shrinkage and acetic acid leakage that occurs when cellulose diacetate deteriorates. Fabrics, membranes, filaments, and several consumer goods have all been produced using cellulose diacetate. It was used to create film stock from 1922 to 1957, primarily in smaller forms including 8 mm, 16 mm, 35 mm, and 70 mm. Additionally, seed coating applications have made use of it. Safety film is the name given to a cellulose diacetate-based film substrate in photography.
Cellulose triacetate
Acetate esters, mainly acetic anhydride, are used to create cellulose triacetate, also known as triacetate, CTA, or TAC. Triacetate is frequently used to make fibres and the foundation of films. It shares chemical properties with cellulose acetate. Triacetate differs from other compounds in that at least “92 percent of the hydroxyl groups are acetylated.” The cellulose is entirely acetylated during the production of triacetate, as opposed to only partially during the production of regular cellulose acetate or cellulose diacetate. Triacetate withstands heat a lot better than cellulose acetate.
c) Synthetic fibers
Contrary to artificial fibres made from natural elements like cellulose or protein, synthetic resources, such as petrochemicals, are used exclusively in their production.
The two classes of fibres used in reinforced plastics are (i) short fibres, also known as discontinuous fibres, with a general aspect ratio (defined as the ratio of fibre length to diameter) between 20 and 60, and (ii) long fibres, also known as continuous fibres, with a general aspect ratio (defined as the ratio of fibre length to diameter) between 200 and 500.
d) Metallic fibers
Metallic fibres can be drawn from more ductile metals, like nickel, aluminium, or iron, and extruded from more brittle ones, like copper, gold, or silver.
e) Carbon fiber
Although the finished result is virtually entirely carbon, carbon fibres are frequently made from oxidised and carbonised polymers, such as PAN, through pyrolysis.
f) Silicon carbide fiber
Fibres made of silicon carbide, also known as poly-carbo-silanes, are composed of basic polymers rather than hydrocarbons, with around 50% of the carbon atoms replaced by silicon atoms. The result of the pyrolysis is an amorphous silicon carbide, which has mechanical properties that are extremely similar to those of carbon fibres but also contains largely additional elements, such as oxygen, titanium, or aluminium.
g) Fiberglass
Other synthetic fibres derived from natural raw materials include silica fibre, made from sodium silicate (water glass), and basalt fibre, made from molten basalt. Fibreglass is made from a particular type of glass, while optical fibre is made from purified natural quartz.
h) Mineral fibers
Because they are created with few surface flaws, including asbestos, mineral fibres can be especially strong.
Polymer fibers
- Polymer fibres are a subclass of artificial fibres that are created using solely physical processes from synthetic chemicals rather than natural materials (typically from petrochemical sources). These fibres are constructed of polyester, nylon, polyamide, or PBT.
- Polyvinyl chloride fibre (PVC) with phenol-formaldehyde (PF) (PP and PE) vinyon polyolefins Pure polyester, acrylic polyesters, and olefin fibre Carbon fibre is produced from PAN fibres that have been roasted in a low oxygen atmosphere. Wool substitutes made of synthetic material are more frequently made of conventional acrylic fibre. The only resin-based fibres that are not thermoplastic are carbon and PF fibres; the majority of the rest can be melted.
- Twaron, Kevlar, and Nomex are examples of aromatic polyamids (aramids), which thermally deteriorate at high temperatures but do not melt.
- Polyethylene (PE), eventually having HMPE (ultra-long polyethylene chains) (such as Dyneema or Spectra).
- Even so, urethane fibres are starting to replace spandex technology, making it possible to use elastomers like spandex.
- fibrous polyurethane
- Elastolefin
- Coextruded fibres are made up of two different polymers, typically in the form of a core-sheath or side-by-side. There are fibres that are coated, such as nickel-coated fibres that reduce static, silver-coated fibres that have antibacterial qualities, and aluminum-coated fibres that deflect RF signals from radar chaff. Radar chaff is essentially an aluminum-coated spool of continuous glass tow. It is chopped up when it is emitted from a moving aircraft by an aircraft-mounted high-speed cutter to fool radar systems.
Microfibers
Microfibers, also known as microdenier fibres, were developed in Japan at the beginning of the 1980s. Microfibers made of acrylic, nylon, polyester, lyocell, and rayon are also available. Germany’s Hoechst A.G. began manufacturing microfibre in Europe in 1986. In 1990, DuPont introduced this fibre to the US market.
Sub-denier fibre, such polyester pulled to 0.5 denier, is referred to as microfiber in the context of textiles. Two metrics of fibre yield based on weight and length are denier and Dtex. It is easier to measure diameters in micrometres unless the fibre density is known, in which case you also have the fibre diameter. Technical fibres that are used in filtering frequently refer to ultra-fine fibres (made of glass or meltblown thermoplastics) as microfibers. Extruding fibre that splits into several finer fibres is a feature of more recent fibre designs. The majority of synthetic fibres have a circular cross section, however certain types might have hollow, oval, star-shaped, or trilobal patterns. More optically reflecting qualities are offered by the latter design. When creating a woven, nonwoven, or knitted construction, synthetic textile fibres are frequently crimped to add bulk. Also possible are dull fibre surfaces.
Typical properties of selected fibers
Fibres can be classified as either natural or synthetic, and the performance of each type will vary depending on the use. In a variety of applications, synthetic fibre materials are progressively taking the place of more traditional materials like glass and wood. This is so that they can be tailored to specific technical engineering through chemical, physical, and mechanical engineering of artificial fibres. A manufacturer would weigh a fiber’s qualities against the technical demands of the applications while selecting it. To choose from a variety of fibres for manufacture.
Sources of fibres
- Beans. In salads, soups, and stews, lentils and other beans are a simple way to add fibre to your diet.
- Broccoli. This vegetable might be labelled as a fibre vegetable.
- Berries. …
- Avocados. …
- Popcorn. …
- Whole Grains. …
- Apples. …
- Dried Fruits.
Importance of fibres
Fibre helps the body use glucose more carefully, which helps to regulate the appetite and blood sugar levels. For optimal health, children and adults require at least 25 to 35 grammes of fibre daily, but the majority of Americans only consume approximately 15 grammes.
