The new esde Extruder ESE 1-50-42 VR
In plastics processing, costs are largely determined by the raw material being processed. For economic and ecological reasons, the proportion of recycled regrind is continuously increasing. However, increasing this proportion in film extrusion presents challenges: Fluctuations in material properties affect production processes and product quality.
Challenge accepted!
First, the good news: Direct processing of regrind on single-screw extruders offers clear advantages, as no additional processing steps are required. However, regrind has a significantly lower bulk density than granules – resulting from a chip-like structure and uneven wall thickness distribution. This makes it difficult to achieve a stable, quasi-steady operating point in the extrusion process.
Active and passive approaches have been developed and tested for this problem. Passive measures relate to the execution of the procedural unit, while active approaches address higher-level regulations.
A key task is the material feed into the extruder, which is intended to ensure a constant bulk density. Degassing also plays a crucial role in achieving good melt quality.
New screw geometry especially for high proportions of regrind
Ground materials have already undergone one or more processing steps. Therefore, it is important to ensure that the melt is not subjected to excessive stress.
The new screw geometry has been lengthened to accommodate a larger degassing zone.
Easily plasticizable components should not be overheated during processing. At the same time, it must be ensured that components that melt later are also plasticized. Therefore, after degassing, the material is mixed sufficiently dispersively and distributively to produce a homogeneous melt.
ZIM-Project in cooperation with the KTP
The development of the regrind extruder was supported by the Central Innovation Program for SMEs (ZIM) of the german Federal Ministry for Economic Affairs and Energy (BMWE).
Our cooperation partner, Kunststofftechnik Paderborn (KTP) at the University of Paderborn, Germany, took on the task of adapting the measurement and control technology. Special thanks go to Prof. Volker Schöppner and research associate Timm Rempel for the successful collaboration. The project work and the exchange with our partner have generated significant new knowledge.
Development of the extruder design
A key aspect is the design of the feed zone. Two tasks must be fulfilled: ensuring material supply directly at the extruder inlet without bridging, and controlling the influence on the bulk material density in such a way that the most constant mass flows possible are achieved in the venting zone.
Achieving the desired compaction of the ground material in the feed zone without producing significant local pressure increases is significantly more complex. The geometry finally found helps support the equally optimized degassing zone.
The result: The new esde Extruder ESE 1-50-42 VR
(VR = venting for recycled materials)
The solids handling of the regrind is significantly improved by a new conical feed zone, allowing a higher proportion of regrind to be processed without disruption.
The integration of the systems and the precise design enable an innovative solution for the processing and quality assurance of recycled materials.
This esde extruder impresses with modern drive technology and a screw geometry specifically designed for regrind – outstandingly energy-efficient.
The esde Extruder ESE 1-50-42 VR implements a consistent concept for economically and ecologically sensibly utilizing the growing proportion of regrind in plastics extrusion. Thanks to the optimized feed zone and appropriate degassing, this new extruder delivers stable melt quality.
You can find more information about our extruders for regrind here.