Continuous polymerization and direct fiber spinning and systems for accomplishing same

Abstract

Continuous anionic polymerization and melt-spinning of a polycaprolactam includes forming a reaction mixture by bringing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator into contact with one another, and then subjecting the reaction mixture to anionic polymerization reaction conditions to obtain a molten polycaprolactam. The molten polycaprolactam is the directly (i.e., without intermediate solidification) transferred to, and extruded through, a fiber-forming orifice of a spinneret to form a fiber thereof. One exemplary system to achieve such continuous anionic polymerization and melt-spinning of polycaprolactam includes a mixer for receiving and mixing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator, and a reactor and melt-spinning apparatus downstream of the mixer. The reactor and melt-spinning apparatus most preferably is formed of multiple plates which establish a reactor zone having a flow path for the reaction mixture which is sized and configured to achieve a predetermined residence time of the reaction mixture therein, and a temperature control zone in thermal communication with the reactor plate for controlling the temperature of the reaction plate to achieve anionic polymerization reaction conditions while the reaction mixture is flowing along the defined flow path therein to obtain the molten polycaprolactam. A spinneret zone downstream of the reactor zone thus receives the molten polycaprolactam directly and forms a fiber therefrom by extruding it through the spinneret's fiber-spinning orifice.