DIE FOR EXTRUSION MOLDING OF THERMOPLASTIC RESIN AND MOLDING OF POLYESTER FILM USING THE SAME

摘要

PROBLEM TO BE SOLVED: To mold a polyester film free from a die line by subjecting only the lip on an anti-taking-over side among a pair of die lips to R processing or corner cut processing. SOLUTION: A die and die lips are formed so as to have a structure such that an R processing part 3 of 0.1-5.0mm, pref., 0.5-2mm or corner cut processing part is provided to the leading end of the die lip only on an anti-gaking-over side 32 among the die lips. R processing is an abridgment of round processing and the leading end of each die lip usually finished at a right angle is rounded to be formed into a circular arc shape. By this constitution, an extruded resin film is pulled rearwardly along the lip 32 on the anti-taking-over side to go away from the lip 31 on a taking-over side and, therefore, deteriorated matter becomes hard to adhere and the adhesion and growth of discharges are suppressed and no die line is generated.