PROCESS FOR THE CONTINUOUS REMOVAL OF RESIDUAL MONOMERS AND THE POST-POLYMERISATION OF POLYAMIDE 6, AND APPARATUS FOR CARRYING IT OUT

摘要

Melts are continuously freed from monomer and are post-polymerised simultaneously under vacuum in a reactor which is a horizontal cylinder containing a driven rotor. This rotor has annular surface discs and/or perforated discs and/or spoked wheels and/or rings which are partly immersed in the melt. Solid lactam is fed into a heated vessel and stirred, together with any additives used (e.g. water, acetic acid, pigments); the vessel has a condenser. A constant speed pump feeds the prepolymer into the bottom of the reactor, from which the final product is also removed by a constant speed pump and supplied to individual spinning points. Reactor contains the rotor, which has a shaft carrying a series of features (26) by struts. These features form a cylindrical cage, whose annular discs dip into the polymer as they rotate. Volatiles escape into the space which is evacuated; they escape through the vent to a condenser. The discs are set at an angle to the end discs; the base also has baffles.