Abstract: Methods, apparatuses, systems, and techniques relate to an extruder unit for producing preforms with a tube-like wall from a polymer melt and an associated extrusion process. The extruder unit has a receptacle for an exchangeable dispensing tool, it furthermore comprises at least two different and alternately usable profiling devices. These profiling devices have outlet-side fastening structures, which correspond in the various profiling devices and form the receptacle for the exchangeable dispensing tool, so that the profiling devices can be connected alternately to the same dispensing tool. In this way, any dispensing tool, depending on the wish of the customer, can be operated with different profiling devices, in particular, on the one hand, to carry out profiling by mandrel body movement or profiling by nozzle body movement.

Abstract: Methods, apparatuses, systems, and techniques relate to a tube-forming device for an extruder unit or an extrusion device and a tube-forming process. The tube-forming device comprises at least one shaping sleeve, which is designed to shape a supplied stream of polymer melt from a substantially strand-like cross section into a tubular cross section. The shaping sleeve has a guiding passage embedded in the sleeve wall, such that the guiding passage is a cavity which lies within the sleeve wall and, in the radial direction of the shaping sleeve, is enclosed in a sealed manner with respect to the outer surfaces.

Abstract: A melt distributor (1) having a plurality of bifurcated melt passages melt passages (5.1, 5.2, 5.3) for redirecting and distributing melt flows from a thermoplastic plastic. The melt distributor can be connected to a multiple extrusion head for producing multi-layer preforms. The branched junction (8) is configured as a rounded y-shaped conduit branch, and at least the branched junction (8) between a supply passage part (6) and the discharging passage parts (7.1, 7.2) of the bifurcated melt passage follows a continuously bent curve, the curvature of which is not equal to zero. The rounded and continuously bent configuration of the branched junction (8) contributes to shorter flow paths and avoids the formation of dead zones.