A METHOD OF MANUFACTURING OPAQUE WHITE FILM

摘要

PURPOSE: A method for manufacturing a white film is provided to prevent the generation of breakage in a fabrication process of the film using inorganic materials of a controlled form and to obtain excellent gross, white, and opacity. CONSTITUTION: A method for manufacturing a white film comprises the following steps: manufacturing a master batch which contains barium sulfate with a refractive index of 1.6-1.7 and a particle size distribution of 5 volume % or less; manufacturing a sheet by extruding a mixture of the master batch and a polyester resin; stretching the manufactured sheet in one-axis or two-axis; heat-treating the stretched sheet in a tender of five stages or more at 180~230°C; and heat-setting the sheet at 200~250°C.