The introduction of German high-end 3-layer biaxial stretching equipment, together with the technology of Swiss clean company, the workshop can reach the level of 100 clean, which creates a solid foundation for the production of optical grade polyester film. The tensile strength of bi-oriented polyester film is 3 times higher than PC film and nylon film, and the impact strength is 3-5 times higher than BOPP film. BOPET film has good heat resistance and unique optical properties.