Chemical fibers refer to those fibers that are made of natural or synthetic high polymers and processed by chemical methods. They can be divided into two categories: man-made fibers and synthetic fibers. There are two kinds of man-made fibers, namely man-made cellulose fibers (such as viscose fibers, strong fibers, etc.) and man-made protein fibers (such as soybean fibers, peanut fibers, etc.), while the camp of synthetic fibers is relatively large, including polyester fibers (ie polyester fibers). ), polyamide fibers (nylon 6, nylon 66, etc.), polyacrylonitrile fibers (acrylic fibers), polyvinyl formal fibers (vinylon), polypropylene fibers (polypropylene), polyvinyl chloride fibers (polyvinyl chloride), polyurethane Formate fiber (spandex). The composition material contains more than 85% of the components of polyurethane, the trade names are Lycra (Lycra, the United States, the United Kingdom, the Netherlands, Canada, Brazil), Neolon (Neolon, Japan), Dorlastan (Dorlastan, Germany) Wait.
First, it was successfully researched by the German Bayer Company in 1937. The American DuPont Company started industrial production in 1959 and has now sold its spandex industry to the American Koch Industries Group, with a total production capacity of about 100,000 tons. At present, the total global spandex production capacity is about 600,000 tons, and the spandex production capacity of South Korea's Hyosung Company is close to 120,000 tons, becoming the world's first. The first spandex enterprise in China was Yantai Spandex Factory, which started production in 1989. The current production capacity of mainland China is about 350,000 tons, making it the world's largest producer of spandex.

There are two varieties of spandex, one is inlaid copolymer of aromatic diisocyanate and polyester segment containing hydroxyl group (referred to as polyester spandex), the other is inlaid by aromatic diisocyanate and
polyether segment containing hydroxyl group Copolymer (referred to as polyether spandex). Spandex fiber, elastic polyolefin fiber and elastic composite fiber are collectively referred to as elastic fiber.