MANUFACTURING METHOD OF POLYESTER FIBER HAVING HIGH STRENGTH AND LOW CONTRACTIBILITY

摘要

PURPOSE: A manufacturing method of polyester fiber having excellent shape stability, high strength, low contractibility and a spinning operating property is characterized by using ethylene naphthalate as a main repeat unit and controlling the temperature of the right lower part of a base. The polyester fiber is useful for a belt or a tire cord. CONSTITUTION: Polyester fiber is obtained by the steps of: (a)melt-polymerizing polymer out of ethylene naphthalene-2,6-dicarboxylate, and spinning the polymer having 0.45-1.30 of ultimate viscosity through the spinning base; and (b)passing through a cooling drum; spinning and drawing polymer stream on a godet roll and then heat-setting. In the spinning base, the temperature of the lower part is 30-50deg.C higher than a melting bath of polymer. In passing through the godet roll, spinning stress is 0.01-0.1/d.