Abstract: A process for the manufacture of extruded articles by extruding polyamide-imide polymers and copolymers through melt flow channels and extrusion dies at ever increasing shear rates ranging from 0.1 sec.sup.-1 to about 2000 sec.sup.-1. The extruder barrel and melt flow channel temperatures range from about 480.degree. to about 600.degree. F. and the extrusion die temperatures range from about 575.degree. to about 680.degree. F. Also, the addition of polyetherimides and polysulfones is disclosed. Thin films, thin sheets and hollow tubes are disclosed. All these articles are useful in engineering applications requiring high temperature resistant plastics. Useful applications include use in the aerospace and automobile industry.

Abstract: The continuous in-line melt flow rate control system (40; 100) is coupled to a mixer/extruder system (10; 97) including a polymer, stabilizer and degradent feeding system (12, 16, 18; 102) supplying mixed materials to the inlet end of an extruder (24; 108) having a die head (26) at the outlet end thereof. The control system (40; 100) is coupled between a rheometer (42; 112) which monitors a slip stream (46; 110) of melt from the extruder (24; 108) and a ratio controller (48; 93) in the feeding system (12, 16, 18; 102).