Extrusion molding method and extrusion molding apparatus for thermoplastic liquid crystal polymer film

摘要

PROBLEM TO BE SOLVED: To provide a method and equipment for the extrusion molding of thermoplastic liquid crystal polymer films which can improve the uniformity in shape of thermoplastic liquid crystal polymer films to be obtained with the use of a ring die. SOLUTION: The gap G (mm) of a ring slit 36 in a ring die 3 is set in the range of 0.2=G=1.0; L/Dout which is a value of the passage length L (mm) (land length) of the gap G of the ring slit 36 calculated as (Lout+Lin)/2 from the inner wall passage length Lout (mm) of the outer piece 31 of the ring die and the outer wall passage length Lin (mm) of the inner piece 32 of the ring die divided by the inner diameter Dout (mm) of the discharge portion of the outer piece 31 of the ring die is set in the range of 5=L/Dout=15; and the molecular orientation SOR of a thermoplastic liquid crystal polymer immediately after discharge in all circumferential directions along the ring slit 36 in the ring die 3 is controlled to not less than 1.45 to not more than 1.55.