Spandex fiber {INVISTA}, contains data for yarn formation/spinning

Spandex or elastane is a synthetic fiber composed of a long-chain polymer comprised of at least 85% segmented polyurethane. The synthetic fiber formed has exceptional elasticity. It can be stretched to >500% of its original length without breaking and it will recover to very near its original length and shape. It is stronger, more durable and has a higher retractive force than rubber. It is lightweight and provides a combination of garment comfort and fit, preventing bagging and sagging. These desirable attributes extend the life of garments. This segmented block copolymer is formed in a multi-step process. The process involves the initial formation of a pre-polymer which is further reacted into a polymer in the presence of solvent. Polymer is then dry spun into a fiber and the solvent recovered and re-used in a closed loop process. Solution dry spinning is used to produce >90% of the world's spandex fibers. A finish agent is applied to the spun fiber to prevent them from sticking together and to aid in textile processing. The finished product is packaged and shipped to customers. Electricity is supplied from the national electricity grid but there is also on-site energy generation for services such as steam.