SHEET-SHAPED BASE MATERIAL OF ARAMID FIBER FOR ELECTRIC INSULATION AND METHOD FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To suppress the production of foreign matters and increase the product yield of a sheet-shaped base material of an aramid fiber for electric insulation which comprises singly or mainly polyparaphenyleneterephthalamide fiber. SOLUTION: The polyparaphenyleneterephthalamide has been treated by pressure cooker processing (pressure of about 2,000 hPa; temperature of about 120 deg.C; and processing time of about 20 hr). At first, a polyparaphenyleneterephthalamide having larger crystal sizes and increased strength is subjected to the pressure cooker processing to construct a sheet- shaped base material (nonwoven fabric or woven fabric) singly or mainly of the fiber.