Elastaan

Elastaan, also known as elastane or spandex, is a synthetic fiber formed from segmented polyurethane. In Europe the term elastaan or elastaan is common; in the United States the generic name spandex is used and Lycra is the well-known brand name.

Elastaan provides exceptional elasticity to fabrics. It can stretch many times its original length (typical elongation up to 500–600%), and it recovers quickly after release. The fiber itself is lightweight with a smooth hand, and it is frequently used in blends to impart stretch without adding bulk.

Limitations: Exposure to high temperatures can reduce elasticity; chlorine in swimming pools can degrade elastane; prolonged UV exposure may cause fiber damage; it is relatively sensitive to certain solvents and oils, and it loses strength when stretched extensively.

Manufacture and use: Elastaan is produced by polymerizing diisocyanates with polyols to create segmented polyurethane, which is dissolved and spun into fibers by wet spinning. In textiles it is commonly blended with cotton, polyester, nylon or wool to provide stretch.

History: Developed in the mid-20th century by DuPont; commercialized as Lycra in the late 1950s and early 1960s. Since then elastane has become a standard component in sportswear, underwear and stretch denim.