1. The elastic 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 500%. 95 to 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. The breaking strength of the strength 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 of different varieties of spandex has a large difference in heat resistance. Most of the fibers are stored at 95 to 150 ° C for a short period of time without damage. 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. The specific gravity of the spandex is 1.00 to 1.25 g/cm 3 , and the specific gravity of the spandex of different brands is different, and the thickness of the same spandex spandex is also different.
6. The chemical resistant spandex is resistant to most acids, bases and chemical solvents, and the varieties that bear it 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.
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