Lycra Fiber
“Lycra is a translation of the English word LYCRA. As a spandex fibre, it consists of flexible and rigid chain segments in a block of molecular chains, polyamino methyl ester. It was successfully researched by Bayer in 1937 and produced by DuPont in 1959, and is a registered trademark of DuPont Spandex. Recognised by its peers for its many advantages and good quality, any garment that uses Lycra will have a triangular hangtag, and this hangtag has become a symbol of high quality.
Although Lycra is a synthetic stretch fibre, also known as spandex in the USA, and spandex is a generic name for the same substance as elastane, only Lycra produces the true LYCRA® (Lycra®) fibre.
Difference between spandex and lycra
1 Lycra is a type of spandex, but spandex is not necessarily lycra
Lycra is better than normal spandex and has a special chemical structure that prevents it from growing mould even when it is wet and sealed in a hot and humid space.
2 Spandex is a polymer compound elastic fibre
Spandex, also known as a polyurethane type fibre, has advantages that are unmatched by other fibres, such as: lighter specific gravity, higher breaking strength, higher elongation at break and better elastic recovery.
3 Lycra can stretch up to 500% and return to its original shape
Lycra is far more stretchable than traditional elastic fibres, it can be stretched very easily and can still fit snugly on the surface of the human skin after recovery, with very little binding force on the human body.
Features of Lycra fibres
1Wide range of fibre finenesses
Lycra fibres range in fineness from 22 to 4778 dtex, with the finest rubber yarn being 156 dtex. As Lycra is more evenly tensioned than other elastic fibres in the weaving process, fabrics containing Lycra have good flatness and are soft to the touch.
2 Higher strength and elongation
Lycra is two to four times stronger than rubber yarn. As Lycra has greater elasticity than rubber yarn at the same elongation, fabrics containing Lycra have a higher elasticity.
3 High temperature resistance
Stretch fabrics are generally made from a small amount of elastic fibres mixed with other fibres. Conventional synthetic fibres heat setting, dyeing must go through high temperature heat treatment, so blended with elastic fibres must also withstand high temperature heat treatment. The heat setting temperature of Lycra can reach 195°C, while the maximum heat setting temperature of other brands of elastane is 180 to 185°C. Therefore, under the same high temperature conditions, the stretch rate and resilience of fabrics containing Lycra are more advantageous than other elastic fabrics.
4 Low washing shrinkage and growth rate
The washing shrinkage rate and growth rate of the fabric are the main factors affecting the dimensional stability and wrinkle resistance of the garment, and are also important indicators reflecting the deformation of the fabric and the garment. Washing shrinkage rate and growth rate is low, indicating that the garment is good conformability and the fabric is not easy to deformation and wrinkle.
5 Good stretching and resilience
Appropriate reply and hold degree give elastic fabric comfortable stretching, form keeping, fit and formability. Lycra can be stretched to a length 7 times longer than the original without breaking; the retractability is also good, with a retractability of greater than 99% when stretched at 50%; a retractability of 97% when stretched at 200%; and a retractability of more than 90% even when stretched at 500%. The size of its shrinkage is related to the thickness of the yarn, the thicker the yarn, the greater the resilience.
6 Dyeable
Lycra can be dyed with acid, metal complex, reactive and disperse dyes, while rubber yarns are not easy to dye.
7 Anti-ageing and non-yellowing
Spandex-containing fabrics or processed clothing, with the continuation of time, repeated use or washing will produce yellowing, while the elastic blank containing Lycra placed for three months, its whiteness is much better than other spandex fabrics, whiteness to maintain 10% ~ 20% better than the general product, while having better anti-aging properties.
8 Good abrasion resistance
In the elongation range of 50% ~ 300%, 200 times per minute fatigue test, can withstand more than 1 million times without breaking, while rubber only 240,000 times.
9 Good light and chlorine resistance
Lycra in the sunlight fastness tester 40 h, the strength of about 20% reduction. The same exposure of rubber yarn leads to ageing and a total loss of strength.
Lycra is resistant to chemicals in general, but is relatively sensitive to chlorine (e.g. NaClO bleach), which causes yellowing and damage to the fibres and makes them lose their elasticity and extensibility, which is one of its main disadvantages. It is more stable to bleaching agents containing oxygen.
The wide range of uses for Lycra
Lycra is mainly found in fabrics in the form of corespun/wrapped/covered and bare yarns, which have good dyeing properties and serviceability and have been used in a wide range of areas in the production of textile products. Its application in the apparel industry is also very common, ranging from light and intimate underwear to heavy outerwear, from sportswear to fashion suits, etc.
1 Different finenesses of Lycra can be used in different applications
The range of fineness of Lycra is from 22 to 4778 dtex, and different finenesses of Lycra can be used in different fields.
Transparent stockings: 11~44 dtex.
Weft knitted knitted fabrics: 22~195 dtex;
warp-knitted knitted fabrics: 22~78 dtex;
Woven fabrics: 44 to 156 dtex.
leggings: 78 to 156 dtex.
warp-knitted knitted fabrics for corsets: 156 to 540 dtex.
Narrow belts, waistbands: 156 to 1880 dtex.
medical articles: 156 to 1880 dtex.
Footwear: 620~940 dtex.
2 Lycra has different roles in different fabrics
Lycra has outstanding stretchability. For knitted items, its multi-directional stretch is determined by the fabric itself, and Lycra brings back only the elasticity of stretching. Woven fabrics are only stretchable in the direction in which the Lycra is woven, e.g. in warp knitting (in the straight direction) or weft knitting (in the cross direction).
In woven fabrics: Lycra is used in warp yarns, where the fabric has stretch in the longitudinal direction; in weft yarns, where the fabric has transverse elasticity; in both warp and weft yarns, where Lycra is used, where the fabric has bi-directional elasticity.
In knitted fabrics: in weft knitted knitted fabrics, bare Lycra is used for light flat knitted fabrics; Lycra covered yarns are used for hosiery, cuffs of knitted pullovers, etc.; core yarns are often used in knitted pullovers and light flat knitted fabrics for underwear; wrapped yarns are often used in ribbed knitted fabrics. Lycra is used in warp-knitted knitted fabrics mainly to increase the extensibility of the fabric, making the garments have excellent applicability and comfort.
In narrow band fabrics: narrow band fabrics are widely used in lingerie and sashes. Lycra provides long-lasting and comfortable high-performance stretch in narrow-band fabrics. It can be used to produce thin and delicate decorative bands for modern, ultra-light women’s underwear that improve and maintain their shape and form.
Advantages of Lycra for clothing
1 Good stretch and elasticity, not easily deformed
Lycra is made up of spandex fibres, which enhance the elasticity of the fabric and can be used in combination with a variety of different fibres, whether natural or artificial, without changing the appearance and texture of the fabric. For example, wool + Lycra fabrics have good elasticity and better fit, conformability, drape and washability; cotton + Lycra not only has the comfort and breathability of cotton fibres, but also takes into account the good elasticity and non-deformable properties that cotton does not have, making the fabric more flattering, form-fitting, soft and comfortable. Lycra can add unique advantages to garments such as comfort, freedom of movement and long-term shape retention.
2 Lycra can be used in any fabric
Lycra can be used in a wide range of fabrics, generally not on its own, but in conjunction with other fabrics, and can be used in any fabric, such as cotton knitted fabrics, double-faced wool fabrics, silk poplin, nylon fabrics and different cotton fabrics.
3 Lycra’s comfort
Lycra fabric has good stretch, does not make people feel depressed and uncomfortable, and and cotton, knitting and other fabrics combined with soft and comfortable, breathable. Wearing clothes containing Lycra, it is comfortable to fit and move freely, realising the unity of dressing decently and comfortably, meeting the needs of people in contemporary society for dressing clothes.
4 The influence of Lycra on style
After Lycra has been added to the clothing, the garments are not tightly fitted; the garments are well-fitted, fitted and unrestrained, and have better drapability; children’s clothing is even more dynamic and can be jumped around freely after wearing. Even well-made suits and jackets don’t feel tight or constricted, and knitted fabrics such as sweatshirts, underwear and bodysuits are made with Lycra so that they fit and feel comfortable, and stretch and move as much as they want.
5 Lycra design features
Whether loose or slim, it is comfortable and natural to wear; it drapes well, has no creases, is not too loose and fits perfectly, reflecting the beauty of simplicity and generosity; it is always close to the body and is stylish and beautiful.
6 Disadvantages of Lycra
Lycra has inherent flaws. Firstly, a Lycra fabric must be blended with other fibres before it can be shaped, otherwise it is difficult to become a fabric that can be used directly; secondly, compared to modal and cotton fabrics, Lycra fabrics are slightly less soft; finally, the service life of Lycra fabrics is shorter. It is best to use ordinary neutral cleaning products for cleaning.
