POLYESTER FILM

摘要

A method for manufacturing a biaxially oriented polyester film is provided to prepare a biaxially oriented polyester film with excellent transparency while maintaining process runnability. A method for manufacturing a biaxially oriented polyester film comprises the steps of: (i) mixing and melting polyester and particles with a particle size of 30~540 nm and refraction index differential (Deltan) with polyester of 0.3 or less, and extruding the molten material to a sheet; (ii) quickly cooling the sheet; (iii) drawing the sheet 2~5 times at 80~150 °C longitudinally and drawing the sheet 2~5 times transversely to prepare a film; and (iv) heat-setting the sheet at 220~250 °C.