How many forms of spandex elastic fiber yarn are there?
Spandex elastic fiber is mixed with other fibers and spun into elastic yarn. There are currently three forms of yarn: spandex core-spun yarn, spandex twisted yarn and spandex covered yarn. The three forms of yarn are essentially different in processing principles and structural properties. Therefore, their uses and weaving properties also vary greatly. The structural diagrams of the three types of yarns are shown in Figure 2-4.
What is the origin of spandex fiber and its main properties?
Spandex fiber is a type of elastic fiber. Elastic fiber is collectively called Spandex abroad. The product name in my country is spandex. In fact, spandex is only a major category of elastic fiber. Spandex fiber (Polyurethane Fibre) is referred to as PU fiber. There are two varieties. One is a copolymer embedded with aromatic diisocyanate and polyester segments containing hydroxyl groups, which is referred to as polyester spandex. The other variety is made of aromatic diisocyanate and hydroxyl-containing polyester segments. Polyether segment-embedded copolymer of hydroxyl groups is referred to as polyether spandex. The representative trade name of polyester spandex is Vyrent, and the representative trade name of polyether spandex is Lyera.
The main properties of spandex fiber are: usually an elongation of 500% to more than 700%, and good elastic recovery performance. It retracts 97% at 200% elongation and over 99% at 50% elongation. The relative density difference of various spandex is small, generally 1.20~1.25, the breaking strength is 4.41~8.82cN/tex (0.5~1.Og/denier), and the strength of polyester spandex is lower , polyether spandex has higher strength. The moisture absorption rate is generally 0.3% to 1.2%. The moisture absorption rate of multifilament is slightly higher than that of monofilament. The heat resistance is generally between 95 and 150°C. Short-term storage will not damage the fiber. The safe ironing temperature is 150°C. the following. Fiber burns slowly and forms a gelatinous residue after burning. It has excellent dyeing performance, can be dyed in a variety of colors, and has strong affinity for dyes. It has good acid and alkali resistance, can be bleached, and does not become moldy. </p
