Elastic fiber filament is an essential material in our daily lives. Without it, there would be no women's stockings, summer swimsuits, or tight fitting clothes that highlight their figure... Elastic fibers have made an indelible contribution to showcasing human figures and enjoying the comfort of wearing them. The elastic fiber we often see in clothing ingredients is spandex. However, if you think spandex is just spandex, then you are wrong. Our weaving staff tirelessly research and develop new fibers and technologies, and strive to make more contributions to the human clothing industry.

According to the definition of the American Society for Testing and Materials (ASTM), elastic fiber filaments will repeatedly stretch at least twice the original length of a fiber at room temperature, and can quickly recover to its original length after releasing tension. The following six types of fibers can be referred to as elastic fibers. Diene elastic fabric (rubber yarn) - Diene elastic fibers are commonly referred to as rubber yarn or elastic yarn, with an elongation typically between 100% and 300%. The main chemical component is sulfurized polyisoprene, which has good chemical and physical properties such as high temperature resistance, acid and alkali resistance, and wear resistance. Rubber yarn is an early type of elastic fiber used. Due to its main production of coarse yarn, its use in woven fabrics is very limited. Polyurethane fiber (spandex) - Polyurethane elastic fiber refers to fibers made from block copolymers mainly composed of polyurethane. It is called spandex in China. The original name of the United States was Spandex, later changed to Lycra Lycra, the European name was Elastane, the Japanese name was Neolon, and the German name was Dorlastan. Its elasticity comes from the network structure of block copolymers, whose molecular structure is composed of "soft" and "hard" segments. The fiber changes with the block copolymer, so the spinning process does not occur simultaneously. After forming different "mesh" network structures, its elasticity and processing performance also differ.

Polyether ester elastic fiber~Polyether ester elastic fiber is an elastic fiber made by melt spinning polyester and polyether copolymer. It was first produced in 1990. Polyether ester elastic fibers not only have high strength, but also good elasticity. When stretched by 50%, the elasticity of medium strength elastic fibers is equivalent to that of spandex. Under dyeing, polyester fibers can also be processed into elastic fabrics. In addition, they have excellent light resistance, chlorine bleaching resistance, acid and alkali resistance, and are better than ordinary spandex. Due to its excellent acid and alkali resistance, fabrics and polyesters made from it can also undergo alkali reduction treatment to improve the drape of the fabric. This type of fiber also has the advantages of cheap raw materials, easy production and processing, and is a more promising fiber. Polyolefin Elastic Fiber (DOW XLA Fiber) - Polyolefin elastic fiber is made from polyolefin thermoplastic elastomers by melt spinning. The XLA launched by Dow Chemical in 2002 was the first batch of commercially available polyolefin elastic fibers. It is prepared by melt spinning of ethylene octene copolymer (POE) catalyzed by metallocene catalysts. It has good elasticity, a fracture elongation of 500%, resistance to high temperatures of 220 ℃, resistance to chlorine bleaching and strong acid and alkali treatment, and strong resistance to UV degradation. Its production process is relatively simple, with raw material prices lower than spandex, and it produces almost no pollution, making it easy to recycle. Polyolefin elastic fibers have been widely used in recent years due to their excellent properties. Composite elastic fiber (T400 fiber) - ConTEX (ST100 composite elastic fiber, commonly known as T400 elastic fiber in the market) is a new type of composite elastic fiber made from ordinary PET using advanced composite spinning technology by DuPont Sorona; It has a natural permanent spiral curl and excellent swelling, elasticity, elastic recovery rate, color fastness, and particularly soft hand feel. It can be woven separately or interwoven with cotton, viscose, polyester, nylon, etc. to form various styles.

It not only solves the problems of traditional spandex yarn being difficult to dye, having excessive elasticity, complex weaving, unstable fabric size, and prone to aging during use, but also can be directly woven on air jet, water jet, and arrow loom without the need for spandex elastic fibers. Therefore, it is necessary to make foreskin yarn before weaving it on the machine, which can reduce yarn costs and improve product quality uniformity. Hard elastic fibers~The above elastic fibers are all soft elastic fibers that undergo significant deformation and recovery under low stress. From a thermodynamic perspective, elasticity comes from the degree of freedom (or disorder) of the molecular chain, which is the change in system entropy. Therefore, the crystallinity of the aforementioned fibers is very low. However, certain fibers manufactured under special processing conditions, such as polypropylene (PP), polyethylene (PE), and other fibers, are less prone to deformation under low stress due to their higher modulus. Under stress, especially at lower temperatures, it also has better elasticity, so this type of fiber is called hard elastic fiber. The deformation and recovery of hard elastic fibers are significantly different from those of elastic fibers. For example, hard elastic PP fibers are immediately stretched for a second time after being stretched, resulting in a significant decrease in their modulus and strength. However, if it is left for a period of time after stress removal, or if the temperature is raised to completely relax, a second stretch is performed. If stretched, its deformation recovery is basically close to the first curve. This is because when stretching and recovering hard elastic fibers, not only do the long chain segments of the curled molecules in the soft elastic fibers undergo stretching and contraction deformation, but also some micro pore structures undergo changes during the stretching process. The chip network structure has also undergone changes. After these structural changes gradually recover, they can only return to their original state, so they will deform and recover under high pressure called hard elastic fibers. At present, hard elastic fibers have not been widely used in textiles, but due to their different elastic properties from soft elastic fibers, special textiles can be developed.