Single-screw extruder and process for plasticizing plastic polymers

Single-screw extruder for conveying, melting, homogenizing and pressure-building - ie plasticizing - of plastic polymers, but not of rubbers, the single-screw extruder having a screw with a screw diameter D and an effective length L, and wherein the single-screw extruder to is set up to rotate the worm in operation by means of a controller at a peripheral speed, characterized in that • the screw diameter D is 250 mm to 800 mm, and that • the effective length L to the screw diameter D has a ratio L / D of 1 to 8. and that • the controller is set up to operate the screw at a peripheral speed between 0.05 m / s and 1.0 m / s and that • The screw diameter D to the channel depth h has a ratio D / h of 20 to 150 and that • the screw is more smooth.