Name: Md. Uzzal Hossaen ID- 111-0011-002

Spandex or elastane is a synthetic fiber known for its exceptional elasticity. It is strong, but less durable than its major non-synthetic competitor, natural latex. Spandex fibers are produced in four different ways: melt extrusion, reaction spinning, solution dry spinning, and solution wet spinning. All of these methods include the initial step of reacting monomers to produce a prepolymer.

Apparel and clothing articles where stretch is desired, generally for comfort and fit, such as: o Activewear , athletic, aerobic, and exercise apparelo Beltso Competitive swimwearo Cycling jerseys and shortso Dance belts worn by male ballet dancers and otherso Gloveso Hosiery

Polyester :

A polyester, according to BISFA, is "a fiber composed of linear macromolecules having a chain at least 85% by mass of a diol and terephthalic acid". The first polyester was made in the UK in 1941. This polyester, known as polyethylene terephthalate (PET) has become by far the world's major man-made fiber. Other polyesters such as polybutylene terephthalate (PBT) and polytrimethylene terephthalate (PTT) are made but in much smaller quantities.

There are several fibers made from the naturally occurring polymer cellulose, which is present in all plants. Mostly cellulose from wood is used to produce the fibers but sometimes cellulose from short cotton fibers, called linters, is the source. By far the most common cellulosic fiber is viscose fiber. Viscose is defined by BISFA as being "a cellulose fiber obtained by the viscose process". It is known as rayon fiber in the USA. Although several cellulosic fibers had been made experimentally during the 19th century, it was not until 1905 that what has become the most popular cellulosic fiber, viscose, was produced.