In this process, the melt is processed into pipes immediately after leaving the die in a direct extrusion procedure. The necessary ingredients, such as polymer, impact modifier, color pigments, chalk, etc., are supplied via split feed and the melt is homogenized in the extruder. Volatile components are drawn off from the process via a degassing module.
The melt travels via the melt pump to the screen changer, where it is continually filtered. The melt distributes itself in a circle around the die in the downstream pipe head. Pure polypropylene is processed in the overlapping co-extruder. The melt is applied to the pipe as an entirely fine and smooth outer layer film.