Rayon
Overview
Rayon is a manufactured regenerated cellulose fiber
Cellulose fiber
Cellulose fibers are fibres of cellulose from any source, either natural or manufactured.-Textile:In the textile industry regenerated cellulose is used as fibers such as rayon, . Cellulose fibers are manufactured from dissolving pulp...

. Because it is produced from naturally occurring polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...

s, it is neither a truly synthetic fiber
Synthetic fiber
Synthetic fibers are the result of extensive research by scientists to improve on naturally occurring animal and plant fibers. In general, synthetic fibers are created by forcing, usually through extrusion, fiber forming materials through holes into the air, forming a thread...

 nor a natural fiber
Natural fiber
Fibers or fibres are a class of hair-like materials that are continuous filaments or are in discrete elongated pieces, similar to pieces of thread. They can be spun into filaments, thread, or rope. They can be used as a component of composite materials. They can also be matted into sheets to...

; it is a semi-synthetic or artificial fiber. Rayon is known by the names viscose
Viscose
Viscose is a viscous organic liquid used to make rayon and cellophane. Viscose is becoming synonymous with rayon, a soft material commonly used in shirts, shorts, coats, jackets, and other outer wear.-Manufacture:...

 rayon
and art silk
Art silk
Artificial silk or Art silk is a synthetic manufactured fiber which resembles silk but costs less to produce. Frequently, art silk is just a synonym for rayon....

in the textile
Textile
A textile or cloth is a flexible woven material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw fibres of wool, flax, cotton, or other material to produce long strands...

 industry. It usually has a high luster quality giving it a bright sheen.

Some major rayon fiber uses include apparel (e.g. Aloha shirt
Aloha shirt
The Aloha shirt commonly referred to as a Hawaiian shirt is a style of dress shirt originating in Hawaii. It is currently the premier textile export of the Hawaii manufacturing industry. The shirts are printed, mostly short-sleeved, and collared. They usually have buttons, sometimes as a complete...

s, blouse
Blouse
A blouse is a loose-fitting upper garment that was formerly worn by workmen, peasants, artists, women and children. It is typically gathered at the waist so that it hangs loosely over the wearer's body. Today, the word most commonly refers to a woman's shirt but can also refer to a man's shirt if...

s, dress
Dress
A dress is a garment consisting of a skirt with an attached bodice or with a matching bodice giving the effect of a one-piece garment.Dress may also refer to:*Clothing in general*Costume, fancy dress...

es, jacket
Jacket
A jacket is a hip- or waist-length garment for the upper body. A jacket typically has sleeves, and fastens in the front. A jacket is generally lighter, tighter-fitting, and less insulating than a coat, which is outerwear...

s, lingerie
Lingerie
Lingerie are fashionable and possibly alluring undergarments.Lingerie usually incorporates one or more flexible, stretchy materials like Lycra, nylon , polyester, satin, lace, silk and sheer fabric which are not typically used in more functional, basic cotton undergarments.The term in the French...

, linings
Lining (sewing)
In sewing and tailoring, a lining is an inner layer of fabric, fur, or other material inserted into clothing, hats, luggage, curtains, handbags and similar items....

, scarves, suit
Suit (clothing)
In clothing, a suit is a set of garments made from the same cloth, consisting of at least a jacket and trousers. Lounge suits are the most common style of Western suit, originating in the United Kingdom as country wear...

s, necktie
Necktie
A necktie is a long piece of cloth worn for decorative purposes around the neck or shoulders, resting under the shirt collar and knotted at the throat. Variants include the ascot tie, bow tie, bolo tie, and the clip-on tie. The modern necktie, ascot, and bow tie are descended from the cravat. Neck...

s, hat
Hat
A hat is a head covering. It can be worn for protection against the elements, for ceremonial or religious reasons, for safety, or as a fashion accessory. In the past, hats were an indicator of social status...

s, sock
Sock
A sock is an item of clothing worn on the feet. The foot is among the heaviest producers of sweat in the body, as it is able to produce over of perspiration per day. Socks help to absorb this sweat and draw it to areas where air can evaporate the perspiration. In cold environments, socks decrease...

s), the filling in Zippo
Zippo
A Zippo lighter is a refillable, metal lighter manufactured by Zippo Manufacturing Company of Bradford, Pennsylvania, U.S. Thousands of different styles and designs have been made in the seven decades since their introduction including military ones for specific regiments.-Establishment:George G...

 lighter
Lighter
A lighter is a portable device used to generate a flame. It consists of a metal or plastic container filled with a flammable fluid or pressurized liquid gas, a means of ignition, and some provision for extinguishing the flame.- History :...

s, furnishings (e.g.
Encyclopedia
Rayon is a manufactured regenerated cellulose fiber
Cellulose fiber
Cellulose fibers are fibres of cellulose from any source, either natural or manufactured.-Textile:In the textile industry regenerated cellulose is used as fibers such as rayon, . Cellulose fibers are manufactured from dissolving pulp...

. Because it is produced from naturally occurring polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...

s, it is neither a truly synthetic fiber
Synthetic fiber
Synthetic fibers are the result of extensive research by scientists to improve on naturally occurring animal and plant fibers. In general, synthetic fibers are created by forcing, usually through extrusion, fiber forming materials through holes into the air, forming a thread...

 nor a natural fiber
Natural fiber
Fibers or fibres are a class of hair-like materials that are continuous filaments or are in discrete elongated pieces, similar to pieces of thread. They can be spun into filaments, thread, or rope. They can be used as a component of composite materials. They can also be matted into sheets to...

; it is a semi-synthetic or artificial fiber. Rayon is known by the names viscose
Viscose
Viscose is a viscous organic liquid used to make rayon and cellophane. Viscose is becoming synonymous with rayon, a soft material commonly used in shirts, shorts, coats, jackets, and other outer wear.-Manufacture:...

 rayon
and art silk
Art silk
Artificial silk or Art silk is a synthetic manufactured fiber which resembles silk but costs less to produce. Frequently, art silk is just a synonym for rayon....

in the textile
Textile
A textile or cloth is a flexible woven material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw fibres of wool, flax, cotton, or other material to produce long strands...

 industry. It usually has a high luster quality giving it a bright sheen.

Uses

Some major rayon fiber uses include apparel (e.g. Aloha shirt
Aloha shirt
The Aloha shirt commonly referred to as a Hawaiian shirt is a style of dress shirt originating in Hawaii. It is currently the premier textile export of the Hawaii manufacturing industry. The shirts are printed, mostly short-sleeved, and collared. They usually have buttons, sometimes as a complete...

s, blouse
Blouse
A blouse is a loose-fitting upper garment that was formerly worn by workmen, peasants, artists, women and children. It is typically gathered at the waist so that it hangs loosely over the wearer's body. Today, the word most commonly refers to a woman's shirt but can also refer to a man's shirt if...

s, dress
Dress
A dress is a garment consisting of a skirt with an attached bodice or with a matching bodice giving the effect of a one-piece garment.Dress may also refer to:*Clothing in general*Costume, fancy dress...

es, jacket
Jacket
A jacket is a hip- or waist-length garment for the upper body. A jacket typically has sleeves, and fastens in the front. A jacket is generally lighter, tighter-fitting, and less insulating than a coat, which is outerwear...

s, lingerie
Lingerie
Lingerie are fashionable and possibly alluring undergarments.Lingerie usually incorporates one or more flexible, stretchy materials like Lycra, nylon , polyester, satin, lace, silk and sheer fabric which are not typically used in more functional, basic cotton undergarments.The term in the French...

, linings
Lining (sewing)
In sewing and tailoring, a lining is an inner layer of fabric, fur, or other material inserted into clothing, hats, luggage, curtains, handbags and similar items....

, scarves, suit
Suit (clothing)
In clothing, a suit is a set of garments made from the same cloth, consisting of at least a jacket and trousers. Lounge suits are the most common style of Western suit, originating in the United Kingdom as country wear...

s, necktie
Necktie
A necktie is a long piece of cloth worn for decorative purposes around the neck or shoulders, resting under the shirt collar and knotted at the throat. Variants include the ascot tie, bow tie, bolo tie, and the clip-on tie. The modern necktie, ascot, and bow tie are descended from the cravat. Neck...

s, hat
Hat
A hat is a head covering. It can be worn for protection against the elements, for ceremonial or religious reasons, for safety, or as a fashion accessory. In the past, hats were an indicator of social status...

s, sock
Sock
A sock is an item of clothing worn on the feet. The foot is among the heaviest producers of sweat in the body, as it is able to produce over of perspiration per day. Socks help to absorb this sweat and draw it to areas where air can evaporate the perspiration. In cold environments, socks decrease...

s), the filling in Zippo
Zippo
A Zippo lighter is a refillable, metal lighter manufactured by Zippo Manufacturing Company of Bradford, Pennsylvania, U.S. Thousands of different styles and designs have been made in the seven decades since their introduction including military ones for specific regiments.-Establishment:George G...

 lighter
Lighter
A lighter is a portable device used to generate a flame. It consists of a metal or plastic container filled with a flammable fluid or pressurized liquid gas, a means of ignition, and some provision for extinguishing the flame.- History :...

s, furnishings (e.g. bedspreads, bedsheet
Bedsheet
The bedsheet format was the size of many magazines published in the United States in the first third of the 20th century. Magazines in bedsheet format were roughly the size of Life but with square spines...

s, blanket
Blanket
A blanket is a type of bedding, generally speaking, a large piece of cloth, intended to keep the user warm, especially while sleeping. Blankets are distinguished from sheets by their thickness and purpose; the thickest sheet is still thinner than the lightest blanket. Blankets are generally used...

s, window treatment
Window treatment
A window treatment is an interior decorating element placed on, in, around, or over a window.It may more specifically refer to:* Cornice board* Curtains* Drapery* Molding * Pelmet* Sheer fabrics* Window blinds** Venetian blinds** Shutters...

s, upholstery
Upholstery
Upholstery is the work of providing furniture, especially seats, with padding, springs, webbing, and fabric or leather covers. The word upholstery comes from the Middle English word upholder, which referred to a tradesman who held up his goods. The term is equally applicable to domestic,...

, slipcover
Slipcover
A slipcover is a fitted protective cover that may be slipped off and on a piece of upholstered furniture. Slipcovers are usually made of cloth...

s), industrial uses (e.g. medical surgery
Surgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...

 products, non-woven products, tire
Tire
A tire or tyre is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground...

 cord), and other uses (e.g. yarn
Yarn
Yarn is a long continuous length of interlocked fibres, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery and ropemaking. Thread is a type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or...

, feminine hygiene
Feminine hygiene
Feminine hygiene is a general euphemism used to describe personal care products used by women during menstruation, vaginal discharge, and other bodily functions related to the vulva...

 products, diaper
Diaper
A nappy or a diaper is a kind of pant that allows one to defecate or urinate on oneself discreetly. When diapers become soiled, they require changing; this process is often performed by a second person such as a parent or caregiver...

s, towel
Towel
A towel is a piece of absorbent fabric or paper used for drying or wiping. It draws moisture through direct contact, often using a blotting or a rubbing motion. Common household textile towels are made from cotton, rayon, bamboo, nonwoven fibers or a few other materials.-Types of towels:* A bath...

s). Rayon is a major feedstock in the production of carbon fiber
Carbon fiber
Carbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber...

.

Nitrocellulose

The fact that nitrocellulose
Nitrocellulose
Nitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...

 is soluble in organic solvents such as ether
Ether
Ethers are a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R'. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether"...

 and acetone
Acetone
Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...

, made it possible for Georges Audemars to develop the first "artificial silk" about 1855, but his method was impractical for commercial use. Commercial production started in 1891, but the result was flammable, and more expensive than acetate or cuprammonium rayon. Because of this, production was stopped before World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

, for example in 1912 in Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

. It was briefly known as "mother-in-law silk."

Nathan Rosenstein invented the spunize process by which he turned rayon from a hard fiber to a fabric. This allowed rayon to become a popular raw material in textiles.

Acetate method

Paul Schützenberger
Paul Schützenberger
Paul Schützenberger , French chemist, was born at Strasbourg, where his father Georges Frédéric Schützenberger was professor of law, and his uncle Charles Schützenberger professor of chemical medicine....

 discovered that cellulose can be reacted with acetic anhydride
Acetic anhydride
Acetic anhydride, or ethanoic anhydride, is the chemical compound with the formula 2O. Commonly abbreviated Ac2O, it is the simplest isolatable acid anhydride and is a widely used reagent in organic synthesis...

 to form cellulose acetate
Cellulose acetate
Cellulose acetate , first prepared in 1865, is the acetate ester of cellulose. Cellulose acetate is used as a film base in photography, as a component in some adhesives, and as a frame material for eyeglasses; it is also used as a synthetic fiber and in the manufacture of cigarette filters and...

. The triacetate is only soluble in chloroform
Chloroform
Chloroform is an organic compound with formula CHCl3. It is one of the four chloromethanes. The colorless, sweet-smelling, dense liquid is a trihalomethane, and is considered somewhat hazardous...

 making the method expensive. The discovery that hydrolyzed cellulose acetate is soluble in more polar solvents, like acetone
Acetone
Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...

, made production of cellulose acetate fibers cheap and efficient.

Cuprammonium method

The Swiss
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

 chemist
Chemist
A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties such as density and acidity. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms...

 Matthias Eduard Schweizer (1818-1860) discovered that tetraaminecopper dihydroxide
Schweizer's reagent
Schweizer's reagent is the chemical complex tetraamminediaquacopper dihydroxide, [Cu42]2. It is prepared by precipitating copper hydroxide from an aqueous solution of copper sulfate using sodium hydroxide or ammonia, then dissolving the precipitate in a solution of ammonia.When the entire amount of...

 could dissolve cellulose. Max Fremery and Johann Urban developed a method to produce carbon fiber
Carbon fiber
Carbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber...

s for use in light bulbs in 1897. Production of rayon for textiles started in 1899 in the Vereinigte Glanzstoff Fabriken AG in Oberbruch. Improvement by the J. P. Bemberg AG in 1904 made the artificial silk a product comparable to real silk
Silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...

.

Viscose method

Finally, in 1894, English chemist Charles Frederick Cross
Charles Frederick Cross
Charles Frederick Cross FRS was a British chemist.Born in Brentford, Middlesex, his father was a schoolmaster turned soap manufacturer...

, and his collaborators Edward John Bevan
Edward John Bevan
Edward John Bevan was an English chemist. He became a leader in the affairs of the Society of Public Analysts and editor of The Analyst....

, and Clayton Beadle patented their artificial silk, which they named "viscose
Viscose
Viscose is a viscous organic liquid used to make rayon and cellophane. Viscose is becoming synonymous with rayon, a soft material commonly used in shirts, shorts, coats, jackets, and other outer wear.-Manufacture:...

", because the reaction product of carbon disulfide
Carbon disulfide
Carbon disulfide is a colorless volatile liquid with the formula CS2. The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical non-polar solvent...

 and cellulose
Cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....

 in basic conditions gave a highly viscous solution of xanthate
Xanthate
Xanthate usually refers to a salt with the formula ROCS2-M+ . The name xanthates is derived from Greek ξανθός , meaning “yellowish, golden”, and indeed most xanthate salts are yellow...

. The first commercial viscose rayon was produced by the UK company Courtaulds
Courtaulds
Courtaulds was a United Kingdom-based manufacturer of fabric, clothing, artificial fibres, and chemicals.-Foundation:The Company was founded by George Courtauld and his cousin Peter Taylor in 1794 as a silk, crepe and textile business at Pebmarsh in north Essex trading as George Courtauld & Co...

 Fibers in 1905. Avtex Fibers Incorporated began selling their formulation in the United States in 1910.
The name "rayon" was adopted in 1924, with "viscose" being used for the viscous organic liquid used to make both rayon and cellophane
Cellophane
Cellophane is a thin, transparent sheet made of regenerated cellulose. Its low permeability to air, oils, greases, bacteria and water makes it useful for food packaging...

. In Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, though, the fabric itself became known as "viscose," which has been ruled an acceptable alternative term for rayon by the U.S. Federal Trade Commission
Federal Trade Commission
The Federal Trade Commission is an independent agency of the United States government, established in 1914 by the Federal Trade Commission Act...

.
The method is able to use wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

 (cellulose and lignin
Lignin
Lignin or lignen is a complex chemical compound most commonly derived from wood, and an integral part of the secondary cell walls of plants and some algae. The term was introduced in 1819 by de Candolle and is derived from the Latin word lignum, meaning wood...

) as a source of cellulose while the other methods need lignin-free cellulose as starting material. This makes it cheaper and therefore it was used on a larger scale than the other methods.

Contamination of the waste water by carbon disulfide
Carbon disulfide
Carbon disulfide is a colorless volatile liquid with the formula CS2. The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical non-polar solvent...

, lignin and the xanthate
Xanthate
Xanthate usually refers to a salt with the formula ROCS2-M+ . The name xanthates is derived from Greek ξανθός , meaning “yellowish, golden”, and indeed most xanthate salts are yellow...

s made this process detrimental to the environment
Natural environment
The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....

. Rayon was only produced as a filament fiber until the 1930s when it was discovered that broken waste rayon could be used in staple fiber.

The physical properties of rayon were unchanged until the development of high-tenacity rayon in the 1940s. Further research and development led to the creation of high-wet-modulus rayon (HWM rayon) in the 1950s. Research in the UK was centred on the government-funded British Rayon Research Association
British Rayon Research Association
The British Rayon Research Association was a research institute formed in 1946 by the British Rayon Federation and others. It was funded by the Department of Scientific and Industrial Research and by voluntary funds from industry to investigate the chemical and physical properties of rayon and...

.

Major fiber properties

Rayon is a very versatile fiber and has the same comfort properties as natural fibers. It can imitate the feel and texture of silk
Silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...

, wool
Wool
Wool is the textile fiber obtained from sheep and certain other animals, including cashmere from goats, mohair from goats, qiviut from muskoxen, vicuña, alpaca, camel from animals in the camel family, and angora from rabbits....

, cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....

 and linen
Linen
Linen is a textile made from the fibers of the flax plant, Linum usitatissimum. Linen is labor-intensive to manufacture, but when it is made into garments, it is valued for its exceptional coolness and freshness in hot weather....

. The fibers are easily dyed
Dyeing
Dyeing is the process of adding color to textile products like fibers, yarns, and fabrics. Dyeing is normally done in a special solution containing dyes and particular chemical material. After dyeing, dye molecules have uncut Chemical bond with fiber molecules. The temperature and time controlling...

 in a wide range of colors. Rayon fabrics are soft, smooth, cool, comfortable, and highly absorbent, but they do not insulate body heat, making them ideal for use in hot and humid climates. The highest quality Hawaiian shirts produced between the 1930s and the 1950s that are most sought after by collectors are all made of rayon.

The durability and appearance retention of regular rayon are low, especially when wet; also, rayon has the lowest elastic recovery of any fiber. However, HWM rayon is much stronger and exhibits higher durability and appearance retention. Recommended care for regular rayon is dry-cleaning only. HWM rayon can be machine washed.

Physical structure

Regular rayon has lengthwise lines called striations and its cross-section is an indented circular shape. The cross-sections of HWM and cupra rayon are rounder. Filament rayon yarn
Yarn
Yarn is a long continuous length of interlocked fibres, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery and ropemaking. Thread is a type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or...

s vary from 80 to 980 filaments per yarn and vary in size from 40 to 5000 denier. Staple fibers
Staple (textiles)
A Wool Staple is a naturally formed cluster or lock of wool fibres and not a single fibre. Very many staples together form a fleece.* Image of the staples on the sheep The cluster of wool fibres is made by a cluster of follicles...

 range from 1.5 to 15 denier and are mechanically or chemically crimped. Rayon fibers are naturally very bright, but the addition of delustering pigments cuts down on this natural brightness.

Production method

Regular rayon (or viscose) is the most widely produced form of rayon. This method of rayon production has been utilized since the early 1900s and it has the ability to produce either filament or staple fibers. The process is as follows:
  1. Cellulose: Production begins with processed cellulose
  2. Immersion: The cellulose is dissolved in caustic soda: (C6H10O5)n + nNaOH → (C6H9O4ONa)n + nH2O
  3. Pressing: The solution is then pressed between rollers to remove excess liquid
  4. White Crumb: The pressed sheets are crumbled or shredded to produce what is known as "white crumb"
  5. Aging: The "white crumb" aged through exposure to oxygen
    Oxygen
    Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

  6. Xanthation: The aged "white crumb" is mixed with carbon disulfide
    Carbon disulfide
    Carbon disulfide is a colorless volatile liquid with the formula CS2. The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical non-polar solvent...

     in a process known as Xanthation, the aged alkali cellulose crumbs are placed in vats and are allowed to react with carbon disulfide under controlled temperature (20 to 30°C) to form cellulose xanthate: (C6H9O4ONa)n + nCS2 → (C6H9O4O-SC-SNa)n
  7. Yellow Crumb: Xanthation changes the chemical makeup of the cellulose mixture and the resulting product is now called "yellow crumb"
  8. Viscose: The "yellow crumb" is dissolved in a caustic solution to form viscose
  9. Ripening: The viscose is set to stand for a period of time, allowing it to ripen: (C6H9O4O-SC-SNa)n + nH2O → (C6H10O5)n + nCS2 + nNaOH
  10. Filtering: After ripening, the viscose is filtered to remove any undissolved particles
  11. Degassing: Any bubbles of air are pressed from the viscose in a degassing process
  12. Extruding: The viscose solution is extruded through a spinneret
    Spinneret (polymers)
    Spinneret refers to a multi-pored device through which a plastic polymer melt is extruded to form fibers. Streams of viscous polymer usually exit into cool air or liquid to solidify. The individual polymer chains tend to align in the fiber because of viscous flow. This airstream liquid-to-fiber...

    , which resembles a shower head with many small holes
  13. Acid Bath: As the viscose exits the spinneret, it lands in a bath of sulfuric acid
    Sulfuric acid
    Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...

    , resulting in the formation of rayon filaments: (C6H9O4O-SC-SNa)n + ½nH2SO4 → (C6H10O5)n + nCS2 + ½nNa2SO4
  14. Drawing: The rayon filaments are stretched, known as drawing, to straighten out the fibers
  15. Washing: The fibers are then washed to remove any residual chemicals
  16. Cutting: If filament fibers are desired the process ends here. The filaments are cut down when producing staple fibers


High wet modulus rayon (HWM) is a modified version of viscose that has a greater strength when wet. It also has the ability to be mercerized like cotton. HWM rayons are also known as "polynosic" or can be identified by the trade name Modal
Modal (textile)
Modal is a cellulose fiber made by spinning reconstituted cellulose, often from beech trees. It is about 50% more hygroscopic per unit volume than cotton. It takes dye like cotton and is color-fast when washed in warm water. Modal is a kind of rayon.Textiles made from modal are resistant to...

.

High-tenacity rayon is another modified version of viscose that has almost twice the strength of HWM. This type of rayon is typically used for industrial purposes such as tire cord.

Cupramonium rayon has properties similar to viscose but during production, the cellulose is combined with copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 and ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

 (Schweizer's reagent
Schweizer's reagent
Schweizer's reagent is the chemical complex tetraamminediaquacopper dihydroxide, [Cu42]2. It is prepared by precipitating copper hydroxide from an aqueous solution of copper sulfate using sodium hydroxide or ammonia, then dissolving the precipitate in a solution of ammonia.When the entire amount of...

). Due to the environmental effects of this production method, cupramonium rayon is no longer produced in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

.

Disposal and biodegradability

The biodegradability of fibers in soil burial and sewage sludge was evaluated by Korean researchers who found that biodegradability decreased in the following order: rayon, cotton, acetate (meaning rayon decays more readily than cotton). The ability of individual rayon-based fabrics to repel water was negatively correlated with their speed of degradation (meaning the greater the water-repelling ability of the fibre, the slower it will decompose).

Alternative to cotton

Rising cotton prices in 2010 led clothing makers to begin replacing cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....

 with rayon in their fabrics. Designers such as Isaac Mizrahi
Isaac Mizrahi
Isaac Mizrahi is an American TV presenter, fashion designer, and was the creative director of Liz Claiborne. He is best known for his eponymous fashion lines.-Early life:...

 have incorporated rayon into their newest designs. As demand for rayon increases, companies such as Fortress Paper have been investing in pulp mills to increase production. Rayon now sells for as much as $2.70 per pound, which has led to an increase in the retail price of clothing made with rayon, despite rayon's price advantage over cotton.

Controversies

Rayon has been accused by some as contributing to the destruction of rain forests. Although some of the trees destroyed annually in the world's rain forests might contribute to Rayon production, targeting Rayon itself is probably misplaced. Rayon production can come from a wide variety of trees and most of its yearly production comes from renewable trees.

In early 2010, the U.S. Federal Trade Commission
Federal Trade Commission
The Federal Trade Commission is an independent agency of the United States government, established in 1914 by the Federal Trade Commission Act...

 warned several retailers that six major manufacturers were falsely labeling rayon products as "bamboo
Bamboo
Bamboo is a group of perennial evergreens in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Giant bamboos are the largest members of the grass family....

", in order to appeal to environmentally
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...

 conscious consumers. While rayon may be produced with bamboo as a raw material
Raw material
A raw material or feedstock is the basic material from which a product is manufactured or made, frequently used with an extended meaning. For example, the term is used to denote material that came from nature and is in an unprocessed or minimally processed state. Latex, iron ore, logs, and crude...

, and the two may be used for similar fabric
Fabric
A fabric is a textile material, short for "textile fabric".Fabric may also refer to:*Fabric , the spatial and geometric configuration of elements within a rock*Fabric , a nightclub in London, England...

s (though natural bamboo is not as smooth), rayon is so far removed from bamboo by chemical process
Chemical process
In a "scientific" sense, a chemical process is a method or means of somehow changing one or more chemicals or chemical compounds. Such a chemical process can occur by itself or be caused by somebody. Such a chemical process commonly involves a chemical reaction of some sort...

ing that the two are entirely separate.

Producers

Trade name
Trade name
A trade name, also known as a trading name or a business name, is the name which a business trades under for commercial purposes, although its registered, legal name, used for contracts and other formal situations, may be another....

s are used within the rayon industry to determine the type of rayon used.

Bemberg, for example, is a trade name for cupramonium rayon developed by J. P. Bemberg that is now only produced in Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

 due to United States Environmental Protection Agency
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...

 regulations in the US.

Modal
Modal (textile)
Modal is a cellulose fiber made by spinning reconstituted cellulose, often from beech trees. It is about 50% more hygroscopic per unit volume than cotton. It takes dye like cotton and is color-fast when washed in warm water. Modal is a kind of rayon.Textiles made from modal are resistant to...

and Tencel are widely used forms of rayon produced by Lenzing AG
Lenzing AG
Lenzing AG is a company based in Lenzing, Austria whose main business is textile and nonwovens cellulose fibers and also makes some polymer plastics...

 which is based in northern Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

.

Galaxy, Danufil, and Viloft are rayon brands produced by Kelheim Fibres, a German manufacturer.

Acordis is a major manufacturer of cellulose based fibers and yarns. Production facilities can be found throughout Europe, the U.S. and Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

.

Visil rayon is a flame retardant
Flame retardant
Flame retardants are chemicals used in thermoplastics, thermosets, textiles and coatings that inhibit or resist the spread of fire. These can be separated into several different classes of chemicals:...

 form of viscose which has silica
Silicon dioxide
The chemical compound silicon dioxide, also known as silica , is an oxide of silicon with the chemical formula '. It has been known for its hardness since antiquity...

 embedded in the fiber during manufacturing.

North American Rayon Corporation of Tennessee
Tennessee
Tennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...

 produced viscose rayon until its closure in the year 2000.

Grasim of India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 is the largest producer of rayon in the world (claiming 24% market share). It has plants in Nagda
Nagda
JANMAI JAI NAGARI i.e.Nagda is a city in Ujjain district in the Indian state of Madhya Pradesh. It is an industrial town in the Malwa region of western Madhya Pradesh and is situated on the bank of Chambal River....

, Kharach and Harihar
Harihar
Harihar is a city located in Davanagere District in the Indian state of Karnataka. Harihar also spelled Hari-hara, in Hinduism, a syncretic deity, combining the two major gods, Vishnu and Siva...

 – all in India, as well as joint ventures in Canada, Laos and China.

Further reading

For a description of the production method at a factory in Germany in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, see pages 152–155 of
  • Agnès Humbert
    Agnès Humbert
    Agnès Humbert was an art historian, ethnographer and a member of the French Resistance during World War II.- Early life :...

    , (tr. Barbara Mellor) Résistance: Memoirs of Occupied France, London, Bloomsbury Publishing PLC, 2008 ISBN 9780747595977 (American title: Resistance: A Frenchwoman's Journal of the War, Bloomsbury, USA, 2008)

External links

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