Ausarbeitung und Bewertung werkstofflicher Recyclingkonzepte für thermoplastische Kunststoffe

Translated title of the contribution: Economic evaluation of in-house recycling solutions for thermoplastic post-industrial waste

Sebastian Stieger

Research output: ThesisMaster's Thesis


Within the last decades, the integration of environmental topics in corporate actions has attracted increasing attention due to global issues, such as climate change and a growing scarcity of resources. Consequently, companies created sophisticated solutions on how to implement (polymer) recycling. Especially material recycling of thermoplastic production waste is nowadays state of the art around the world. Additionally, the main reason for implementing recycling in a production plant has changed in many cases from environmental to economic reasons. The first aim of this master’s thesis was to analyse the outsourced material recycling process of Hirschmann Automotive GmbH at their plant in Rankweil (Austria). Secondly, in-house recycling solutions had to be found and adapted to the local conditions. These investment projects must not solely be judged on economic criteria but also on their influence on products and processes. In order to fulfil these requirements, the flow of secondary material was monitored in Rankweil over a period of more than one year (December 2015 – December 2016). Furthermore, each working activity related to the current recycling process was assigned to its actual cost. A comparison between the total costs of the current recycling process and the price of the original material shows a big economic advantage in favour of the recycling process. The first in-house solution contains two central edge mills. In contrast to the currently used granulate the particle size of the grist is irregular and it contains a lot of dust. Consequently, the process fluctuations increase drastically, which could lead to failure of manufactured parts. However, this investment project shows a huge economic success. All technical risks are diminished, when innovative shredder-extruder systems are used instead. Nevertheless, a payback time of more than three years in combination with an uncertain secondary material flow (the use of recycling material has to be confirmed by the customers) leads to a significant financial risk. Another solution, which is based on small edge mills next to every injection-moulding machine, was not even possible to design, because of the highly flexible production planning system. Nonetheless, a dynamic investment calculation shows the great economic success of this concept under special circumstances (the same product is manufactured on the same injection-moulding machine over a long period).
Translated title of the contributionEconomic evaluation of in-house recycling solutions for thermoplastic post-industrial waste
Original languageGerman
  • Biedermann, Hubert, Supervisor (internal)
  • Topic, Milan, Co-Supervisor (internal)
  • Battisti, Markus, Supervisor (external)
Award date20 Oct 2017
Publication statusPublished - 2017

Bibliographical note

embargoed until 19-08-2022


  • recycling
  • polymers
  • dynamic investment calculation
  • sensitivity analysis

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