Spandex is a highly elastic manufactured fiber. It is made of a chainlike arrangement of soft, stretchable segments of the plastics material polyurethane with stiffer segments in-between. When the fibers are relaxed, they stretch easily and can extend up to five times their original length. But as they are stretched, the stiff segments align and maintain strength. Manufacturers vary the lengths of the soft and stiff segments to produce fibers of differing strength and elasticity.
No fabric is made entirely of spandex. Instead, spandex is always used in combination with other fibers. Fabrics that contain spandex are lightweight and resistant to deterioration from perspiration and detergents. They are used to make such clothing as athletic wear, foundation garments, and support hose.
