ROTATING DISC EVAPO-EXTRUSION PROCESS AND APPARATUS THEREFOR

摘要

A process for removing volatile components from a thermoplastic polymer composition which process comprises applying to the composition a pressure sufficient to maintain the composition in a substantially liquid state and all or a part of the heat necessary for evaporating the volatile components to the composition, supplying the heated composition under pressure to a machine, having a rotor 8 and a stator 2 face to face and substantially parallel to define a space 6 therebetween, the composition being supplied to the space through an inlet 5 passing through the stator and arranged to deliver the composition onto the face 7 of the rotor 8, whilst maintaining the pressure in the space 6 at from 5 Torr to 1,500 Torr, rotating the rotor 8 to thereby separate a majority of the volatile components and transfer the polymer composition toward the central area of the face 7 of rotor 8 by hydrodynamic pressure and removing the polymer composition from an outlet 14 which is provided at the central part of the face of stator 2.
The method is particularly useful for the removal of the volatile components from polymer compositions having a high content of volatile components as, for example from 25 to 99.9% by weight, particularly methyl methacrylate polymer compositions for the production of molding meterials or extrusion plates which contain 60% by weight or more of methyl methacrylate monomer.