The polyester production process includes direct esterification (PTA) and transesterification (DMT). The PTA process has the advantages of low raw material consumption and short reaction time. Since the 1980s, the PTA process has become the main process and the preferred technical route for polyester.
PET Chips can be divided into fiber-grade polyester chips, bottle-grade polyester chips, and film-grade polyester chips (mainly due to different process indicators). Fiber-grade polyester chips can be divided into super bright (bright), bright, semi-dull, and (full) dull polyester chips according to the content of TiO2. There are also cationic polyester chips. Fiber-grade polyester chip is used to manufacture polyester staple fiber and polyester filament. It is the raw material for polyester fiber enterprises to process fiber and related products. As the enormous variety in chemical fiber, polyester occupies nearly 80% of the market share in the chemical fiber industry. The production of industrial polyester yarn mainly uses bright chips, and the viscosities are IV 0.678, IV 0.97, and IV 1.1, IV 0.678 is suitable for producing high-tenacity regular shrinkage yarn polyester. IV 0.97 is suitable for producing high-tenacity low shrinkage polyester yarn, and high-tenacity super low shrinkage polyester yarn. Iv1.1 is suitable for the production of high-modulus low, shrinkage polyester yarn.
