A characteristic feature of virtually all twin screw extruders is their modular design. The screw profile can easily be adjusted to the particular needs of a given process task. For this, screw segments (also called screw elements) are mounted onto a common shaft. Different screw segments are designed to give conveying, compression, reverse-conveying, barrier and kneading.
The innately self-cleaning profile can be further optimised to enhance certain characteristics by modification of outer and/or inner diameter as well as the contour. Increases of the intake or conveying capacity, or reduction of temperature and stress peaks, is frequently the reason to abandon the closely intermeshing “Erdmenger”-profile.