1. Spandex fiber has excellent elasticity, and its elastic elongation is the highest among textile fibers, up to 400% to 500%; the elastic recovery rate is also high, up to 95% to 99%.
2. Spandex is a thermoplastic fiber with a softening point of 160°C, safe ironing temperature <150°C, and heat setting temperature between 185 and 190°C.
3. Spandex is a hydrophobic fiber with low hygroscopicity.
4. The relative density of spandex is low, about 1.20, so the texture of the entire spandex is loose.
5. The surface friction factor of spandex is very large, about 0.7 to 1.30, which is 5 to 7 times that of wool (about 0.14 to 0.17 for wool), and 3 to 4 times that of synthetic fibers such as polyester and nylon. Therefore, when spinning spandex yarn, a large amount of silicone emulsion should be used in the spinning oil to facilitate stretching and winding.
6. Spandex is not resistant to ultraviolet rays, and it is easy to yellow after a long time of sun exposure, but it will not cause immediate loss of strength. Polyether spandex is more prone to yellowing than polyester spandex.
7. Spandex is resistant to dilute acid and dilute alkali at room temperature, and its acid resistance is much better than alkali resistance; it is resistant to reducing agents, and it is also resistant to oxidants and bleaches without effective chlorine.