Washing process for inorganic acid containing polyamide fibers

Process for the continuous high-speed production of neutral to very slightly basic polyamide yarn comprising in sequence

• 1. extrusion of an inorganic acid containing spin dope through a plurality of orifices,
• 2. coagulation of the yarn in an aqueous bath,
• 3. stripping of entrained liquid,
• 4. treating the yarn with a caustic solution having a concentration of 0.3 to 1.3%,
• 5. stripping the liquid from the yarn,
• 6. treating the yarn with a caustic solution having a concentration of 0.01 to 0.1%,
• 7. drying the yarn and
• 8. winding the yarn in a package.