Ökonomisch und nachhaltig sinnvolle Nutzung von recyceltem PET als globale Rohstoffquelle für die 3A Composites Core Materials

  • Stefan Hochradl

Student thesis: Master's Thesis

Abstract

(i) Motivation and problem definition The master thesis deals with the economic and sustainable use of recycled polyethylene terephthalate (rPET) in the production of foams by 3A Composites Core Materials. As a leading company in sandwich composite technology, which already uses rPET in some products, 3A Composites is under increasing pressure from customers and regulators to increase the proportion of recycled PET. rPET is not only cheaper to source than virgin PET, it also carries risks, particularly from impurities that affect the production process and reduce the quality of the end product. The central aim of the work is to identify suitable processes for processing rPET in order to eliminate impurities and improve the material properties. (ii) Content structure and methodology The thesis is methodically structured as a case study within the 3A Composites Core Materials. First, a comprehensive literature review is carried out, followed by an examination of the technical fundamentals of foam extrusion and the properties of PET. Two recycling technologies, the liquid condensation process (LSP) and the solid condensation process (SSP), were evaluated in terms of their technical and economic performance. Both processes were tested in practice to ensure the optimum material properties for further processing. In addition to evaluating the processing methods, the work included developing formulations with rPET and carrying out production trials. The aim was to optimize the manufactured product in terms of mechanical and thermal properties and to achieve complete substitution of new PET (vPET) with rPET. (iii) Concrete results of the thesis The tests showed that NGR's LSP process is superior to Starlinger's SSP process due to better material cleaning and stabilization of viscosity. The rPET developed met all the mechanical and thermal specifications that also apply to the processing of vPET. Several recipes for different PET qualities were developed, whereby the use of colored PET flakes in combination with internal production waste was identified as the most cost-effective and ecologically sustainable solution. The production trials carried out proved that rPET meets the quality requirements for the production of foams, especially for products with densities of 100 to 230 kg/m³. The use of rPET showed stable compressive strength, shear strength and thermal stability, which enables long-term economic use.
Date of Award2024
Original languageGerman (Austria)
SupervisorEdith Öller (Supervisor)

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