Production method for 20D/24F complete-extinction nylon 6 fully-drawn yarn

The invention belongs to the field of synthetic fiber processing, relates to a preparation method for a nylon 6 fiber and discloses a production method for a 20D/24F complete-extinction nylon 6 fully-drawn yarn. The production method comprises the following steps of: (1) slicing and drying until the water content is 400-600ppm; (2) extruding and melting by a twin-screw extruder; (3) extracting excessive monomer impurities by a single sucking device and performing spinneret and forming by a spinning manifold; (4) laterally blowing, cooling and oiling at constant temperature and humidity; (5) drafting and setting; and (6) winding to form a silk cake. The production method disclosed by the invention has the advantages of simple and feasible process and low processing cost as well as stable product quality, uniform evenness, low hairness ratio, favorable dyeing effect and excellent mechanical property by optimizing parameters.