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How many of the six commonly used Elastic fiber do you know?

Date:2023-07-07  Visits:6

Elastic fiber is a kind of tow with high extensibility and high resilience. The classic definition is ASTM, a type of fiber that is“Stretched repeatedly to at least twice its original length at room temperature, and then quickly reverted to its original length when the tension is released.” The polyurethane material, refers to the extension to the original length of 3 times, the release of tension can quickly recover the original length of the fiber. In addition, there are other definitions depending on the country and the region.
In many functional varieties, elastic fiber as a“Sunrise industry” because it can give the human body a good sense of touch, in the clothing wearing comfort, fluffiness and warmth play an irreplaceable role, therefore, in China and the world's textile industry to occupy a stable position, and give textile fabrics a certain degree of flexibility has become an inevitable trend of development of clothing textiles.
Diene elastic fiber (rubber wire)
Diene elastic fiber commonly known as rubber wire or rubber tendon, elongation is generally between 100% ~ 300% . The main chemical composition is vulcanized isoprene, with good heat resistance, acid and alkali resistance, wear resistance and other chemical and physical properties, widely used in socks, rib cuffs and other knitting industry. Rubber yarn is an elastic fiber used in the early days. Because it is mainly made into coarse count yarn, its use in weaving is limited.
Polyurethane fiber (spandex)
Polyurethane elastic fiber is a kind of fiber made of block copolymer, which is mainly composed of polyurethane. It is called Spandex for short in our country, it was renamed Lycra, Elastane in Europe, Neolon in Japan and Dorlastan in Germany. Its elasticity comes from its molecular structure of the so-called“Soft” and“Hard” segment composed of block copolymer network structure. The elasticity and dyeing and finishing properties of the fibers are different with different block copolymers, spinning processes and formation of different“Block” network structures.
The spinning methods of spandex include dry spinning, wet spinning, chemical reaction spinning and melt spinning. Dry spinning technology is the most popular method in spandex production, which has the advantages of fast spinning speed (1000 m/min) , small size, good product quality and small workshop area, but at the same time there are serious environmental pollution and high costs and other shortcomings. On the contrary, melt spinning technology, no solvent, coagulant, no waste water treatment, low production costs, has great development potential, is one of the current research hot spots.
Spandex is the earliest developed elastic fiber and the most widely used, the most mature production technology varieties.
Polyether ester elastic fiber
Polyether ester elastic fiber is made of polyester and polyether copolymer by melt spinning elastic fiber, Japan Teijin Company in 1990 the first production. The structure of polyether ester elastic fiber is similar to that of polyurethane elastic fiber, and it also has“Segment” structure. The“Soft” segment is mainly the polyether segment, which has good softness, longer chain and is easy to stretch and deform. The“Hard” segment is the polyester segment, which is relatively rigid, easy to crystallize and short chain, it acts as a joint when the fiber is under stress and deformation, which endows the elastic recovery performance and determines the strength and heat resistance of the fiber.
Polyether ester elastic fiber not only has high strength, but also good elasticity. At 50% elongation, the elasticity of medium strength elastic fiber is equal to that of spandex, and its melting point is also higher. It can be blended with PET fiber and dyed at 120 ~ 130 ° C, therefore, polyester fibers can also be processed into elastic textiles. In addition, their good light resistance, chlorine bleaching resistance, acid and alkali resistance are better than ordinary spandex. Because of its good acid and alkali resistance, the fabric composed of it and polyester can also be processed by alkali deweighting to improve the drape of the fabric.
This kind of fiber also has the advantages of cheap raw materials, easy production and processing, so it is a kind of promising fiber.
Polyolefin elastic fiber (Dow XLA fiber)
Polyolefin elastic fibers are made from polyolefin Thermoplastic elastomer by melt spinning. XLA, launched by Dow Chemical in 2002, is the first commercial polyolefin elastic fiber produced by melt spinning of ethylene-octene copolymer (Poe) catalyzed by metallocene catalyst. It has good elasticity, 500% elongation at break, resistance to 220 ° C high temperature, chlorine bleaching and strong acid and alkali treatment, and has strong anti-ultraviolet degradation performance. Its production process is simple, the raw material price is lower than spandex, at the same time, the production process is almost no pollution and easy to recycle.
Polyolefin elastic fibers have been widely used in recent years because of their excellent properties.
Composite elastic fiber (T400 fiber)
Contex Contex (ST 100 composite elastic fiber, T400 elastic fiber) is a new kind of two-component composite elastic fiber, which is made from dupont Sorona and common PET by advanced composite spinning technology With natural permanent spiral crimp and excellent bulk, elasticity, elastic recovery rate, color fastness and special soft handle, can be woven alone, but also with cotton, viscose fiber, polyester, nylon, etc. , form a variety of styles. It not only solves many problems of traditional spandex, such as difficult dyeing, excessive elasticity, complicated weaving, unstable fabric size, and easy aging in use, etc. , and can be directly in the air-jet, water-jet, arrow loom weaving, not like the spandex must be made before weaving to cover yarn, reduce the cost of yarn, improve product quality uniformity.
Hard elastic fiber
All of the elastic fibers are soft elastic fibers, which produce large deformation and recovery under low stress. From the thermodynamic point of view, the elasticity comes from the degree of freedom (or disorder) of the molecular chain, that is, the change of entropy value of the system, so the crystallinity of the above fibers is very low. But some fibers made under special processing conditions, such as polypropylene (PP) and polyethylene (PE) , are not easy to deform under low stress (because they have a high modulus) , but under high stress, especially at lower temperatures, but also a good elasticity, so this type of fiber is called hard elastic fiber.
The deformation and recovery of hard elastic fibers are obviously different from that of elastic fibers. For example, rigid elastic PP fibers are immediately re-stretched after tensile recovery, and their modulus and strength are much lower, but if the stress is removed and placed for a period of time, or raise the temperature to make it fully relaxed after the second tensile, its deformation recovery and the first basically close to the curve. This is because when the hard elastic fiber is stretched and retracted, not only the stretching and retraction deformation of the long segment of the soft elastic fiber coiling molecule occurs, but also some changes of the micropore structure are accompanied during the stretching process, the structure of their chip networks has also changed. Only after these structural changes gradually recover, can return to the original state, so they occur under high pressure deformation recovery, known as hard elastic fibers.