Polyester fiber, commonly known as "polyester". Polyester fibers, referred to as PET fibers, are polycondensated by organic dibasic acids and diols. They belong to macromolecule compounds. Invented in 1941, it is the largest variety of synthetic fibers at present. The greatest advantage of polyester fiber is that it has good wrinkle resistance and shape retention, and has high strength and elastic resilience. It is durable, wrinkle-resistant, non-ironing and non-sticky.

   After drying and melting, polyester chips can be used for spinning, preparing polyester films, polyester bottles, etc. In the melting process, the moisture contained in the chips can hydrolyze the polyester and affect the spinning performance and fiber quality. Therefore, the moisture content of the chips must be dried before spinning, so that the moisture content of the chips can be reduced to less than 0.01%. In chip spinning, the dried polyester chips are heated and melted in the screw, then extruded into the spinning parts of the spinning box. After accurate measurement and filtration by the metering pump, the dried polyester chips are ejected from the spinneret holes. The diameter of spinneret holes is generally 0.15-0.30 mm. The ejected melt streams are cooled and solidified into filaments by cooling airflow. The chilled filament can be divided into polyester filament and polyester staple (or polyester staple) according to different processing technology.