PRODUCTION OF FOAMED POLYESTER FIBER

摘要

PURPOSE:To provide a process for the continuous production of a foamed polyester fiber having a large diameter and a high foaming ratio and containing fine closed cells in high productivity. CONSTITUTION:A foamed polyester fiber is produced by melting a thermoplastic polyester resin containing a foaming agent in an extruder and extruding the molten resin into a low-pressure region through an extrusion orifice of a die attached to the tip end of the extruder. In the above process, the thermoplastic polyester resin is incorporated with inert inorganic fine particles having an average primary particle diameter of <=2mum as foaming nuclei, at least two inner orifices B1 and B2 are placed immediately before the extrusion orifice A and the resin is extruded by keeping the back pressure of the inner orifice to 50-300kg/cm<2>.