Fibers with high elastic recovery
• Spandexes are elastometric fibers, characterized by high elongation (400 or
500-600%) and low modulus.
• Low modulus means that they have low resistance to extension.
➢ When you first begin to stretch the fibers, the molecules readily give way;
there is little resistance to the stretching. As you stretch more, the
molecules become aligned and the fiber begins to resist extension.
Spandex also called Elastane
• First produced in 1930 by DuPont. Leading US producers today are DuPont
(Lycra Spandex), RadiciGroup (RadiciSpandex) and Hyosung (Creora).
• Spandex is the generic name and comes form turning around the word
• Lycra is a DuPont trade name, and to use the name, garment producers must
adhere to some regulations. Lycra is becoming a commonly used name in a
manner similar to Kleenex, Xerox, and Jell-O.
• Starting materials are polymers manufactured from chemicals derived from
petroleum; the polymers are not found in nature.
• Spandex polymers are 85% segmented polyurethane block copolymers. Hard
blocs hold the structure while soft blocks extend easily.
• Polymers are dissolved in suitable solvent systems and can be wet