Process for the manufacture of polyamide fibers

A process for the manufacture of polyamide fibers which comprises the steps of:

• melt spinning a polyamide having a relative viscosity of not less than 3.50 under the conditions satisfying the following relationships:
• Q/D.sup.3 .ltoreq.982 g/sec.cm.sup.3
• D.sup.2.Vw/Q.ltoreq.12.8 cm.sup.3 /g
• T.sub.20 .gtoreq.100.degree. C.
• .DELTA.n of unstretched filament.ltoreq.0.017
• (wherein Q is the discharge amount per each nozzle hole (g/sec);
• D is the diameter of each nozzle hole (cm.phi.), Vw is the take up speed of spun filaments (cm/sec) T.sub.20 is the atmospheric temperature at a distance of 5 mm from the spun filaments and at a distance of 20 mm from the nozzle face towards the discharge of the filaments (.degree.C.) and .DELTA.n of the unstretched filaments is the value determined after the filaments are allowed to stand at a temperature of 30.degree. C. under a relative humidity of 80% for a period of 24 hours);
• subjecting the resultant filaments to cooling;
• further subjecting the resulting filaments to stretching and heat treatment;
• and
• providing said fibers with a break strength of not less than 11.0 g/d, said break strength (g/d).times.(the break elongation (%)).sup.1/2 being not less than 46.0, and a monofilament denier of not more than 60d.