Lyocell is a fabric most know Lyocell better by its brand name Lyocell owned by Lenzing Application of contemporary Fibres of Austria. Lyocell heralds the beginning of a fibres in apparels new age in fibre technology. Completely natural, Lyocell asically, there are two broad categories of fibres: Natural fibres like cotton, wool, hemp, ramie and silk; and Bartificial fibres synthesized out of petrochemicals like nylon and polyester. Lyocell falls somewhere in- offers a unique combination between. The raw material for lyocell is cellulose from wood pulp, a mix of hardwood trees like oak and birch, of the most desirable although Lyocell branded lyocell is made from eucalyptus trees, which are broken down chemically in a soupy sludge that is squirted out a showerhead spinneret and reformed as fibres. Lyocell is more accurately described properties of manmade and as a recovered or regenerated fibre, although manufacturers’ makes a distinction between regenerated fibres natural fibres: Soft as silk, and lyocell which they describe as a "solvent spun fibre" that keeps the cellulose structure closer to that found in nature. This makes it a natural fabric, and it is noted for its durability and strength, in addition to its eco- strong as polyester, cool as friendly manufacturing techniques. linen, warm as wool and as History absorbent as cotton. The first fabrics made with wood pulp were made as far back as the mid 19th century. They were not universally accepted or very profitable. At the end of the 19th century, a method for creating rayon out of wood cellulose became popular, and rayon became one of the first manmade fibres, as a silk substitute, and an inspiration to later produce lyocell. Success of rayon particularly in the latter 20th century fuelled interest in making other products from wood pulp.
46 APPAREL VIEWS / MARCH 2011 4000 B.C. 3000 B.C. 2600 B.C. 200 B.C. 1939 NOW • Dimensional stability • Low shrinkage WOOL COTTONSILK LINEN POLYESTER TENCEL® • Good wash ability VISCOSE • Can be hand washable
The solvent-spun cellulosic fibre lyocell was first produced commercially in the • Bio-degradable United States in 1992 by Courtaulds Fibres (now Acordis Cellulosic Fibres), an • The fibre is economical in its use of energy and natural resources, and is fully international supplier of rayon. The company used the brand name Lyocell. Lenzing bio-degradable AG had acquired patents and research on lyocell from American Enka when it • Durability bought that company's rayon operation in 1992. In 1996, lyocell became the first • Wrinkle resistant new generic fier group in 30 years to be approved by the Federal Trade Commission as the properties and production processes were unique to designate it as a Since Loycell is a manufactured fibre, the diametre and length of fibres can be separate fibre group. Since then, lyocell has realised increasing visibility and varied. Lyocell can be made into micro fibres (very fine fibres), offering depth and acceptance in the apparel market, especially in designer and better priced garments. body to fabrics combined with luxurious drape. Short staple length fibres give a Its versatility and desirable properties provide many advantages, both functional cotton-like look to fabrics. Long filament fibres are successful in silk-like end uses. and aesthetic. Lyocell blends well with other fibres including wool, silk, rayon, cotton, linen, nylon, and polyester. It successfully takes many finishes, both functional and Federal Trade Commission Definition for Lyocell Fibre: A cellulose fibre obtained by those designed to achieve different surface effects and dyes easily. Overall, lyocell an organic solvent spinning process where: is a versatile fibre with many desirable properties. 1) “Organic solvent” means a mixture of organic chemicals and water, and 2) “Solvent spinning” means dissolving and spinning without the formation of a Important features of Lyocell fibres derivative Moisture Unlike synthetic fibres Lyocell offers unique moisture transport, as a result of nano Although it is given a separate generic name, the FTC classifies Lyocell as a sub- technology. The nano technology of the fibre supports this natural fibre property, category under “Rayon.” guaranteeing optimum conditions for the skin. Synthetic fibres are unable to absorb Fibre properties moisture into the inside of the fibre. The illustration shows that in contrast to cotton and polyester fibres, Lyocell controls and regularly absorbs moisture. Also A manufactured fibre composed of regenerated cellulose. Lyocell has excellent Lyocell absorbs 50 per cent more moisture than cotton. By contrast polyester properties of cellulose fibres. Lyocell fabric feels very cool, moisture permeability; does not absorb moisture. texture can be changed to cotton wool, silk and all kinds of feelings. It is having similar hand and drape as rayon, but is stronger, more durable, and in many cases machine washable. It has a subtle luster and is rich in colour. Lyocell possesses low shrinkage characteristics, as well as good absorbency and wrinkle resistant qualities.
Lyocell fibre characteristics • Texture • Soft, simulates silk, suede, or leather touch Cotton Lyocell Polyester • Great for sensitive skin • Loycell smooth fibre surface feels soft and supple against the skin and its The water is coloured in Green incredible wicking abilities keep the skin dry • Strength MOISTURE (VAPOR) MANAGEMENT WITH EXTREME AIR HUMIDITY • High tensile strength 30% • Excellent wet strength (2X rayon dry/3X rayon wet) 25% • Lyocell fibres dry strength close to the polyester fibre, wet strength decreased 20% only 15 per cent 15% • Moisture absorbent 10% • Highly absorbent 05% • It has natural breathability and 50 per cent greater moisture absorption than 00% cotton POLYESTER COTTON WOOL TENCEL® • Swells radially when wet • Due to its moisture management, it is also anti-bacterial Moisture transport is largely determined by climate. Depending upon climate conditions, Lyocell either absorbs or releases moisture. Compared to other fibres, • Dyeing Lyocell features the highest moisture absorption-rate: With air humidity at 65 per • Lyocell was created with colour in mind, because of the fibres' high absorbency cent, Lyocell still has unused capacity to absorb moisture from the skin. • The fabrics can be dyed to high quality standards • Very versatile fabric dyeable to vibrant colours, with a variety of effects and The skin sensor textures The skin is the largest human respiratory organ. Human skin acts as a protective • Easily dyeable to strong colour-fast shades shell, regulates body temperature and maintains water balance. Lyocell supports these body functions acting like a second skin. A subjective feeling of well-being • Drape depends considerably on moisture absorption and on surface structure of the • Good drapability fibres. Rougher fibres can lead to skin irritation. The extremely smooth surface of • Temperature Lyocell feels soft and pleasant to the skin. The reason • Does not melt for the fine surface of the fibre is low fibre stiffness. • Outperforms cotton and rayon at high temperatures A comparison of the fibre surfaces makes the • Fibrillation difference patently obvious. Lyocell fibre has a • This eco-fabric has controllable fibrillation (the very fine hairs found on the smoother and suppler surface than wool or cotton. outer fibres), which can be manipulated into everything from suede-like softness Wool tends to have a scaly surface, while cotton is to a silky smooth finish irregular and rough.
APPAREL VIEWS / MARCH 2011 47 Application of Loycell • Denim • Suits • Casual clothes • Underwear • Shirts • Knitted Whether the need is denim for casual looks or sueded silk- like ensembles for Cotton Wool Lyocell evening wear, lyocell can create the right look and the right fabric. This by nature is the strongest cellulose fibre and thus ideal for hard-wearing textiles. Lyocell is a godsend for anyone with sensitive skin. The combination of a smooth fibre surface and excellent moisture absorption creates a positive environment Initially, Lyocell was marketed as and can generally be found in high-end and for healthy skin, making Lyocell ideal for anyone with sensitive skin. designer apparel. Production cost is greater than for cotton, making lyocell more expensive in finished garments. However, as production increases, bulk According to recent dermatological studies, wearing clothing made of Lyocell production, and costs decrease, expect to see more lyocell in moderately priced significantly improves comfort and promotes a feeling of well being. Also, Lyocell apparel. Lyocell’s soft drape and luxurious hand make it very desirable in is chemical free, an important factor for sensitive skin and another asset in women’s fashion garments as well as men’s shirts, particularly apparel comparison to other fibres of a natural origin. traditionally made from silk. Other lyocell end uses include denim, chino, and Typical properties of Lyocell fibre chambray casual wear. Look for these fabrics in 100 per cent lyocell as well as in blends with cotton, rayon, or polyester. Property Units Typical values Lyocell gabardines take water resistant finishes for coatings. Other fabrics Denier g/9000m 1.25, 1.5, 2.2, 3.0 successfully made from lyocell include jersey-knits, which exhibit a soft hand and Cut length Mm 0.5 - 25 (precision cut) luster. Nowadays, lyocell is readily available and manufacturers already have Cross-section Round experience in handling it, look for more varieties of fabrics including knits of all Luster Bright, dull types, leotards and hosiery, velvets, velours, and corduroys. Crimp per cm 0 - 2.5 It can be blended with nylon in which the nylon can be on the surface for durability Finish Various and wind and water resistance, while the lyocell has greater exposure on the Dispersibility in water Very good backing surface for warmth, absorbency, and comfort. Blends with wool and wool with Lycra® spandex and nylon have been successful. Blends of lyocell with cotton, Comparison with other fibres linen, and rayon, are becoming popular, especially for spring, summer, and fall Property Units Lyocell Polyester Rayon Cotton fashions. In addition, blends with silk and rayon are common, especially in lightweight silky fabrics including those with sueded surfaces. Dry tenacity g/den 4.5 - 5.0 4.5 - 5.5 2.3 - 2.7 2.3 - 2.7 Elongation at break, dry % 24 - 26 15 - 55 20 - 25 7 - 9 Lyocell denim Wet tenacity g/den 3.9 - 4.3 4.5 - 5.5 1.4 - 1.8 2.8 - 3.4 Lyocell is almost twice as strong as cotton. As a result, Lyocell jeans make Elongation at break, wet % 16 - 18 15 - 55 23 - 35 12 - 14 good sportswear. This new natural fibre provides all the durability required for Water imbibitions % 65 - 70 N/A 90 - 100 44 - 55 in a denim garment, yet it is not harsh to the body or tough-looking. With a Cellulose DP 550 - 600 N/A 250 - 350 2 - 3000 pair of Lyocell jeans wearer can even climb a mountain or ride a horse with Initial modulus, wet g/den* 250 - 270 N/A 40 - 60 200 less fear of damage to the garment. For those who are very active, Lyocell denim is the best choice. *At 5 per cent strain More importantly, Lyocell denim In many ways, lyocell is more similar to cotton than it is to rayon. Like other makes wearer feel much more cellulosic fibres, it is breathable, absorbent, and generally comfortable to wear. In comfortable than cotton denim. fact, lyocell is more absorbent than cotton and silk, but less so than wool, linen, Lyocell denim breathes better. In and rayon. It can take high ironing temperatures, but like other cellulosics will the winter, Lyocell denim keeps scorch, not melt, if burned, and is susceptible to mildew and damage by silverfish. wearer’s body warmer than Cellulosic fibres are not resilient, which means they wrinkle. Lyocell has moderate cotton denim. It is also lighter and resiliency. It does not wrinkle as badly as rayon, cotton, or linen, and some wrinkles easier to pack than heavy jeans in will fall out if the garment is hung in a warm moist area, such as a bathroom after case of travelling to cold climates. 100% Tencel 8.9 OZ a hot shower. A light pressing will renew the appearance, if needed. Also, slight shrinkage is typical in lyocell garments. Stability, overall, is similar to that of silk Hundred per cent Lyocell denim is luxurious, self-indulging, and prestigious. It’s and better than cotton or linen. very soft to the touch and drapes finely. It flows nicely with the body's movements- absolutely an upscale denim. Lyocell/cotton denim creates a look with more body Lyocell has strength and durability. It is the strongest cellulosic fibre when dry, and excellent texture. For those who don't want as much draping, this fabric is a even stronger than cotton or linen and is stronger than cotton when wet. Lyocell good choice-very appropriated for menswear. Lyocell/rayon denim is best is much stronger than rayon when wet. This property of high wet strength usually conceived of as a compromise between 100 per cent Lyocell and Lyocell/cotton. determines the extent to which fabrics can be machine washed successfully. Lyocell/rayon makes very good denim, softly textured with a great feel. Lyocell/ rayon denim is less expensive than 100 per cent Lyocell. Disadvantage of Lyocell • Lyocell will shrink (approx. 3 per cent) after its first washing but retain its shape Kids wear after that The combination of properties in the Lyocell fibre quite simply makes it ideal for • The manufacturing process for lyocell is more expensive than cotton or rayon kid’s wear. Kid’s skin is tender and sensitive and demands the very best materials. • Lyocell is more expensive than most eco-fabric alternatives Lyocell offers all of the properties so much in demand by the sensitive skin of children. Perfect moisture management coupled with skin-sensory properties is • Lyocell fibre has a relatively low surface energy, which makes it difficult for dyes extremely important in the apparel next to children’s skin. to bind to it. This can cause fading • Although Tencel fibres themselves are eco-friendly, some manufacturers use Lyocell’s smooth fibre surface prevents irritations to the skin. Lyocell’s purity is processes such as enzyme baths, chemical processes, and dye treatments another asset since it is not contaminated with agricultural chemicals. The perfect that are in no way "green." These chemical treatments can cause allergies in moisture management of Lyocell -can absorb 50 per cent more moisture than people with sensitivities. cotton – automatically supplies a natural hygiene. Thanks to the particularly high
48 APPAREL VIEWS / MARCH 2011 moisture absorption of Lyocell, the growth of bacteria can be nipped in the bud. Fabrics made from lyocell that is not specially treated to prevent fibrillation are The moisture is transported from the skin directly into the inside of the fibre. Thus usually labelled as "dry clean only.” Reduced moisture and agitation during dry- no film of moisture, which can be the basis for bacterial growth, forms on the fibre. cleaning prevent fibrillation. Home textile Ironing: Lyocell is a cellulosic fibre and, as a result, will wrinkle. It may need a To some extent, lyocell is available in home products including bath towels, slight touch up with a warm iron. Because lyocell is similar to cotton, it can take sheets, pillowcases, and window treatments. Industrial uses for lyocell include medium to high temperature settings. The exception is fabric made from fine conveyor belts (because of the fibre's strength), ultra-low tar cigarette filters, yarns or micro-fibres. Heat will penetrate these fabrics more quickly with the printer’s blankets, abrasive backings, carbon shields, specialty papers, and medical potential for scorching. In many instances, however, wrinkles are likely to hang dressings. out overnight, particularly in a warm, moist environment.
Caring of Lyocell Bleaching: Generally, use of oxygen or chlorine bleaches should not damage the lyocell fibre itself, but may affect either dyes or resin finishes applied to the Washing: Because of its high wet strength and cellulosic or plant base, lyocell fabrics. Also, because the surface of some fabrics can be damaged when wet if can generally be either hand washed or machine washed and tumbled dried subjected to abrasion, avoid excessive rubbing during stain removal. successfully; however, some lyocell fabrics perform best when dry-cleaned. Lyocell will shrink about 3 per cent with the first washing, and will resist shrinking Storing: Moths and mildew can damage garments made by lyocell. It is necessary from then on. that lyocell should be clean and dry when stored in a cool, well-ventilated location. Don't store lyocell in plastic bags. Hand washable/line dry lyocell fabrics are frequently knits (often blended with rayon or cotton) or wovens, such as chambray or sand washed "silk-like" fabrics. Conclusion When wet, fabrics made from lyocell become stiff and almost boardy. Although Today the world demands for “Organic, eco-friendly and bio-degradable” products. this improves as drying occurs, undesirable stiffness may be removed by tossing Lyocell is the environmentally friendly fibre, and, the first truly revolutionary the garment into the dryer with a towel on low temperature to enhance the fabric's fibre introduced to the market since Spandex 40 years ago, is made from wood softness and drape. pulp. Virtually all of the chemicals used in the production process are reclaimed. Machine wash and tumble dry lyocell fabrics are either treated with a special The resulting fibre, lyocell, is both bio-degradable and recyclable. It’s an finish or modified as they are manufactured. These fabrics can be machine washed improved fibre, in terms of performance and properties. Its outstanding, essential and tumble dried much like cotton or cotton/polyester blends are handled in the and desirable properties make it suitable for development of a variety of high home laundry. Medium temperature settings for water and drying are recommended value-added woven and knitted products, an extremely broad market prospect as well as permanent press settings. If line dried, be sure to toss in the dryer with for various end uses. It is easy to conclude that the future scope for Lyocell fibre a damp towel to soften the fabric after it is dry or nearly dry. is definitely vast
Dry cleaning: Lyocell fabrics that require dry cleaning may have either a smooth By Vasant R Kothari or sanded surface. If machine washed or hand washed, it could develop a "hairy" Assistant Professor, NIFT, Bangalore surface. In addition, water spotting may be noticeable in some fabrics that are (Author can be contacted @ www.vasantkothari.com) "spot" cleaned to remove stains. Wrinkling may occur after wetting the fabric.
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