In 1946, the United Kingdom published the first patent for the preparation of PET. In 1949, the British company ICI completed the pilot test. However, after the DuPont Company purchased the patent in 1946, it established a production plant in 1953 and was the first to achieve industrialized production in the world. Most of the initial PET Since the 1980s, PET as a breakthrough has been made in engineering plastics. In succession, nucleating agents and crystallization accelerators have been developed. At present, PET and PBT are used as thermoplastic polyesters and become the five major projects One of the plastics.