Spandex, core yarn related knowledge

1. elasticity

The spandex fiber has great elasticity and can be stretched to 4 to 7 times of the original length under normal conditions. The recovery rate is almost 100% under the stretching of 2 times, and the rebound rate is 95 when the elongation is 500%. ~99%, which is beyond the reach of other fibers. In general, in the molecular structure of spandex fiber, the larger the molecular weight of the soft segment portion, the stronger the elasticity and rebound rate of the fiber, the higher the flexibility and the rebound rate of the polyether type spandex than the polyester type spandex; the chemically crosslinked spandex Resilience is better than physical cross-linking

2. strength

The breaking strength of the spandex fiber is 0.35 to 0.88 CN/dtex in the wet state and 0.44 to 0.88 CN/dtex in the dry state, which is 3 to 5 times that of the rubber yarn. The effective strength can reach 5.28 CN/dtex.

3. Elastic Modulus

The modulus of elasticity is a measure of the ability of an object to resist deformation under external forces. The greater the modulus of elasticity, the less easily the fibers are deformed, the higher the strength but the less flexible. Spandex has a small modulus of elasticity. For example, Lycra is only 0.11 CN/dtex and has good flexibility.

4. Heat resistance

The heat resistance of different varieties of spandex is quite different. Most of the fibers will not be damaged when stored at 95-150 °C for a short time. When it is 150 ° C or more, the fiber becomes yellow, sticky, and the strength is lowered. Since spandex is generally present in fabrics under other fiber coatings, it can withstand higher heat setting temperatures (180 ° C to 190 ° C), but with a shorter time.

5. proportion

The specific gravity of spandex is 1.00-1.25 g/cm3. The specific gravity of different brands of spandex is different, and the thickness of spandex of the same fineness is also different.
6. Chemical resistance

Spandex is resistant to most acids, bases and chemical solvents, and its varieties are poorly resistant to acids and bases. Polyester-type spandex will decompose in hot alkali, and bleaching agents such as sodium hypochlorite will make it yellow and strong.

Stretch Fabrics

Stretch fabric

Stretch fabric is a synthetic fabric that stretches. Stretch fabrics are either 2-way stretch or 4-way stretch.

2-way stretch fabrics stretch in one direction, usually from selvedge to selvedge. 4-way stretch fabrics, such as spandex, stretches in both directions, crosswise and lengthwise. It is distinct from elastic which is not a fabric but a notion.

It is made partially of elastic fibers such as lycra, elastane, spandex (different names of the same synthetic fiber).

Lycra (elastane or spandex) increases the wear resistance of the product, at the same time it doesn`t neutralize the advantages of other materials.

Preserves all the positive properties of breathability, water-absorbing function, hypoallergenicity

Stretch fabrics are perfect for leisure pants, sportwear shorts and beachwear.


Stretch Fabrics,Elastane Fabric,Stretch Lace Fabric,Stretch Cotton Fabric

Wujiang Fuhua Fabric Co., Ltd , https://www.texfuhua.com

Posted on