FDY stands for Fully Drawn Yarns. Fully drawn yarns are also called Polyester Filament Yarn (PFY) or Spin Draw Yarn (SDY). These yarns are fully drawn yarns fixed by various processes such as  drawing, orientation and crystallization. Full stretch yarn is mainly used for polyester fiber. These high-stretch polyester filaments are mainly used in the production of high-strength fabrics and  textiles. In the weaving process of textiles, fully stretched yarn is mainly used as weft or fabric.

Fully stretched yarn can be used as the first raw material for twisting and can be directly used for knitting. During the knitting and weaving process, FDY can be blended with other filaments to  produce different varieties of fabrics. By twisting these polyester yarns, polyester embroidery thread and polyester sewing thread can also be produced. These yarns are widely used, mainly for home  fabrics, fashion fabrics, denim, terry cloth and so on. Other applications of FDY include the production of premium underwear, premium sportswear, household goods and non-woven fabrics.

The full stretch yarn is mainly divided into three kinds according to its luster: semi-dark yarn (SD), bright yarn (BR) and bright yarn (TBR).  The Bright FDY is a circular section and Trilobal Bright FDY is a triangular section.  Curtains, sheets and carpets are mainly made of filament and have a trilobated sheen.

As per shrinkage , FDY threads have different applications.

• High Shrinkage yarns: FDY yarns have a high shrinkage rate, are used in the manufacture of fabrics and curtain fabrics, and form a flowering structure on the fabric surface.

• Low shrinkage yarns: FDY yarn has the characteristics of low shrinkage rate and is widely used in the knotted blanket industry.