Polyester is a polymer compound. Polyethylene terephthalate (PET) is produced by polycondensation of terephthalic acid (PTA) and ethylene glycol (EG), and part of the PET is finally formed by underwater pelletizing. Fiber-grade polyester chips are used to manufacture polyester staple fibers and polyester filaments. They are used as raw materials for processing fiber and related products of polyester fiber enterprises. Polyester is the largest variety of chemical fiber, accounting for nearly 80% of the chemical fiber industry. The market changes and development trends of the polyester series are the focus of the chemical fiber industry. At the same time, polyester is also used in bottles, films, etc., and is widely used in the packaging industry, electronic appliances, medical and health, construction, automotive and other fields. Packaging is the largest non-fiber application market for polyester, and it is also the fastest growing field for PET. . It can be said that polyester chips are an important intermediate product for connecting petrochemical products and products in many industries.