How Much Do You Know About Lycra Fiber?

Among the many new types of fibers, one that is often seen in the composition table of apparel fabrics is Lycra fiber. What is Lycra fiber? What are its advantages and disadvantages? Let's take a look together!

01、Understand Lycra fiber

"LYCRA" is the transliteration of the English word LYCRA. As a kind of spandex elastic fiber, a block molecular chain segment composed of flexible segments and rigid segments is polyurethane. It was successfully researched by Bayer in Germany in 1937, and DuPont began production in 1959. It is a registered trademark of DuPont spandex fiber. Because of its many advantages and good quality, it is recognized by the peers, so as long as the clothing that uses Lycra will be hung with a triangle tag, this tag has also become a symbol of high quality.

Although Lycra fiber is a synthetic elastic fiber, also known as spandex in the United States, and spandex and elastic fiber are the common names of the same substance, only Lycra produces real LYCRA® (Lycra®) fiber.

So, what is the difference between Spandex and Lycra?

02, the difference between spandex and lycra

1) Lycra is a kind of spandex, but spandex is not necessarily Lycra

Lycra has better performance than ordinary spandex. It has a special chemical structure and will not grow mold in a sealed space with humidity and heat.

2) Spandex is a kind of high molecular compound elastic fiber

Spandex, also known as polyurethane fiber, has advantages that other fibers cannot match, such as light specific gravity, high breaking strength, high breaking elongation, and good elastic recovery.

3) Lycra can stretch up to 500%, and it can be restored to its original shape

The stretch of Lycra is much better than traditional elastic fibers. It can be stretched very easily, and it can still stick to the surface of the human skin after recovery, and has little restraint force on the human body.

03, the characteristics of Lycra fiber

1) Wide range of fiber fineness

Lycra fiber fineness range is 22~4778 dtex, the finest rubber filament is 156 dtex. Because Lycra has more uniform tension during the weaving process than other elastic fibers, the fabric containing Lycra has good flatness and soft hand feeling.

2) Higher strength and elongation

The strength of Lycra is 2~4 times that of rubber yarn. Because Lycra has greater elasticity than rubber yarn under the same elongation, the fabric containing Lycra has a higher degree of tightness.

3) High temperature resistance

Stretch fabrics are generally made of a small amount of elastic fibers mixed with other fibers. The heat setting and dyeing of conventional synthetic fibers must be subjected to high temperature heat treatment, so the elastic fiber for blending must also withstand high temperature heat treatment. The heat setting temperature of Lycra silk can reach 195℃, while the highest heat setting temperature of other brands of elastic fibers is 180~185℃. Therefore, under the same high temperature conditions, the stretch rate and resilience of Lycra fabrics are more advantageous than other elastic fabrics.

4) Washing shrinkage rate and growth rate are low

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 it is also an important indicator reflecting the deformation of the fabric and the garment. The washing shrinkage rate and growth rate are low, indicating that the garment has good shape retention and the fabric is not easy to deform and wrinkle.

5) Good stretchability and resilience

Proper recovery and retention give the elastic fabric comfortable stretchability, shape retention, fit and formability. Lycra can be stretched to 7 times longer than the original length without breaking; the shrinkage is also very good, when the elongation is 50%, the retraction rate is greater than 99%; when the elongation is 200%, the retraction rate is 97%; When it grows 500%, its shrinkage rate is also over 90%. The shrinkage rate is related to the thickness of the yarn. The thicker the yarn, the greater the resilience.

6) Can be dyed

Lycra can be dyed with acid, metal complex, reactive and disperse dyes, while rubber yarn is not easy to dye.

7) Anti-aging and not easy to yellow

Fabrics or processed garments containing spandex yarns will turn yellow after repeated use or washing over time, while elastic blanks containing Lycra will be placed for three months, and the whiteness is much better than other spandex fabrics, and the whiteness is maintained. It is 10%~20% better than general products and has better anti-aging properties.

8) Good abrasion resistance

In the elongation range of 50%~300%, the fatigue test can be done 200 times per minute, which can withstand more than 1 million times without breaking, while the rubber has only 240,000 times.

9) Good light resistance and chlorine resistance

Lycra is exposed to the light fastness tester for 40 hours, and the strength is reduced by about 20%. However, the rubber thread undergoes the same irradiation, which leads to aging and loss of strength.

Lycra has certain resistance to general chemicals, but it is relatively sensitive to chlorine (such as NaClO bleach), which causes yellowing damage to the fiber and loss of elasticity and extensibility. This is one of its main shortcomings. It is relatively stable to oxygen-containing bleaching agents.

04, Lycra's wide range of uses

Lycra mainly appears in the form of core-spun yarn/wrapped yarn/covered yarn and bare yarn in fabrics. It has good dyeing properties and wearability, and has been widely used in various fields of textile product production. Its application in the clothing industry is also very common, from light and thin underwear to heavy outerwear, from sportswear to fashionable suits.

1) Lycra of different fineness can be used in different fields

Lycra fiber fineness range is 22~4778 dtex. Lycra of different fineness can be used in different fields.

Transparent stockings: 11~44 dtex;

Weft knitted fabric: 22~195 dtex;

warp knitted fabric: 22~78 dtex;

Woven fabric: 44~156 dtex;

Leg socks: 78~156 dtex;

Warp knitted fabric for bras: 156~540 dtex;

narrow belt, waist belt: 156~1880 dtex;

Medical items: 156~1880 dtex;

Footwear: 620~940 dtex.

2) Lycra has different functions in different fabrics

Lycra has outstanding stretchability. For knitwear, its multi-directional extension is determined by the fabric itself, and what Lycra brings is only the elasticity of stretching and recovery. Woven fabrics are only malleable in the direction in which they are woven into Lycra, such as warp knitting (straight direction) or weft knitting (horizontal direction).

In woven fabrics: Lycra is used for warp yarns, and the fabric has stretchability in the longitudinal direction; used for weft yarns, the fabric has horizontal elasticity; when Lycra is used in warp and weft yarns, the fabric has two-way elasticity.

In knitted fabrics: bare lycra yarns in weft knitted fabrics are used for lightweight plain knits; lycra covered yarns are used for cuffs of hosiery and knitted pullovers, etc.; core-spun yarns are often used for lightweight flat knitted sweaters and underwear. Needle knitted fabric; wrapping yarn is often used for rib knitted fabrics. Lycra used in warp knitted fabrics is mainly to increase the extensibility of the fabric, so that the garment has excellent applicability and comfort.

In the narrow belt fabric: The narrow belt fabric is widely used in underwear and clothing belts. Lycra provides long-lasting and comfortable high-performance elasticity of the narrow band fabric. It can be used to produce thin and exquisite decorative belts for modern ultra-light women's underwear to improve and maintain its appearance and body shape.

05. Advantages of Lycra for clothing

1) Good stretchability and elasticity, not easy to deform

Lycra is composed of spandex fiber, which can enhance the elasticity of the fabric, and can be used in combination with a variety of different fibers, whether it is natural or man-made fibers, it will not change the appearance and texture of the fabric. For example, wool + lycra fabric has good elasticity, and has better fit, shape retention, drape and washability, etc.; cotton + lycra not only has the advantages of comfort and breathability of cotton fiber, but also takes into account what cotton does not have. The characteristics of good elasticity and resistance to deformation make the fabric more close-fitting, fit, soft and comfortable. Lycra can add unique advantages to clothing, such as close-fitting comfort, freedom of movement and long-term retention of shape.

2) Lycra can be used in any fabric

Lycra fabrics are widely used. Generally, they are not used alone, but combined with other fabrics, and can be used in any fabric, such as cotton knitted fabrics, double-sided wool fabrics, silk poplin, nylon fabrics and different cotton fabrics.

3) The comfort of Lycra

Lycra fabric has good stretchability, will not make people feel depressed and uncomfortable, and when combined with cotton, knitted and other fabrics, it is soft, comfortable, and has good air permeability. Wearing lycra fiber-containing clothing, comfortable fit, free movement, to achieve the unity of proper dressing and comfort, to meet the needs of contemporary society for clothing.

4) Lycra's influence on style

The clothing styles of Lycra fabrics are beautiful and diverse. After adding Lycra to the clothing, the close-fitting clothing is not tight; the clothing stretches well, fits and does not restrict, and has better drape; children's clothing is full of vitality and can jump after wearing freely. Even the production of rigorous suits and jackets will not have the slightest sense of urgency and cramps. The addition of Lycra to knitted fabrics such as undershirts, underwear and fitness pants will fit and feel comfortable, and can stretch freely and move as you want.

5) Design features of Lycra

Whether it is a loose or slim design, it is comfortable and natural to wear; it has good drape, no wrinkles, nor too loose, and a perfect fit, which fully reflects the simple and generous beauty; enjoy it close to the body at all times, and it is stylish and beautiful.

06、Disadvantages of Lycra fabric

Lycra fabric has inherent defects. First of all, a Lycra fabric must be blended with other fibers to be formed, otherwise it will be difficult to be a fabric that can be used directly; secondly, compared to fabrics made of modal, pure cotton and other materials, Lycra fabric is slightly inferior in softness; finally, Lycra The service life of the fabric is short. At the same time, attention should be paid to the maintenance and cleaning of Lycra fabrics. It is best to use ordinary neutral cleaning products for cleaning.