a twin screw extruder the pressure is raised and the dope is transferred to a spinning head using a metering pump the spinning dope is extruded through a spinneret with 668 orifices an orifice diameter of 0 22 mm orifice length of 0 40 mm entering angle of 20 degrees and orifice density of 5 cm 2 the spinning temperature is 165 u00b0 c and the discharge rate per single orifice is 0 23 g min the distance between the spinneret and the quench chamber is 2 cm and the length of the quench chamber is 20 cm the temperature of the air flow in the quench chamber is 70 u00b0 c and the air flow rate is 0 7 m sec the filaments are drawn by a pair of dry rollers positioned 150 cm below the spinneret face at a speed of 200 m min next the fiber filaments are led to a staple cutter rotary cutter located under the pair of rollers and cut into fibers 45 mm long the cut fiber filaments are collected on a conveyer belt the weight of the filaments is about 1 49 denier per filament thereafter the cut staple fibers are transferred into the first washing bath containing a 10 percent.