Features and characteristics of spandex knitted fabrics

- 2020-12-14-

The characteristics and characteristics of spandex knitted fabrics are introduced. Spandex has excellent elasticity. It is two to three times stronger than latex, has a finer linear density, and is more resistant to chemical degradation. The acid and alkaline resistance, sweat resistance, seawater resistance, dry cleaning resistance, wear resistance of spandex are better.


Spandex knitted fabric features synthetic fibers with high breaking elongation (over 400%), low modulus and high elastic recovery rate. Chinese trade name of multi-block polyurethane fiber. Also known as elastic fiber. Spandex has high extensibility (500% ~ 700%), low elastic modulus (200% elongation, 0.04 ~ 0.12 g/Dan) and high elastic recovery rate (200% elongation, 95% ~ 99%). The other physical and mechanical properties are very similar to those of natural latex, except for the stronger ones. It is more resistant to chemical degradation than latex silk, with moderate thermal stability, softening temperature of about 200℃ above. Most of the dyes and finishing agents used for natural fibres in synthetic and synthetic fibres are also suitable for dyeing and finishing spandex. Spandex is resistant to sweat, seawater and various dry lotions and most sunscreens. Long-term exposure to sunlight or chlorine bleach also causes bleaching, but the degree of bleaching varies greatly with the type of ammonia fiber.


The reason spandex fiber has such high elasticity is because its polymer chain is composed of a low-melting, amorphous "soft" chain matrix and a high-melting, crystalline "hard" chain embedded in it. The molecular chains of the flexible chain segment form a certain network structure in a certain cross-linked form. Due to the small intermolecular chain phase interaction force, the intermolecular chain can be freely telescoped, resulting in large elongation. The binding force of the rigid chain segment molecules is relatively large, and the molecular chain will not extend unlimitedly, resulting in high elasticity of the loop. Most of the cross sections of radon fiber filament are dog-bone-shaped, but some of the surface light of the filament is smooth or serrated. The breaking strength of all textile fibers is the lowest, with only 0.44 ~ 0.88CN/dtex(polyether type is stronger than polyester type).


The hygroscopic range is small, generally 0.3-1.2%(the hygroscopic rate of composite wire is slightly higher than that of single wire). The heat resistance varies greatly depending on the varieties. Most of the fibers are stored in a short time within the range of 90 ~ 150℃, and the fibers will not be damaged. The safe ironing temperature is below 150℃, which can be heated to dry and wet washed. Has a better dyeing properties, can be dyed various colors, strong affinity to fiber, dyes can adapt to most of the product of the kind of dye, and has good chemical resistance, resistance to most of the acid and alkali, chemical reagent, organic solvents, dry cleaners and bleach, and resistant to sun and wind and snow, but not resistant oxide, easy to make the fiber with strong reduction.