Sorting multilayer packaging is still a major challenge in the recycling of post-consumer plastic waste. In a 2019 Germany-wide field study with 248 participants, lightweight packaging (LWP) was randomly selected and analyzed by infrared spectrometry to identify multilayer packaging in the LWP stream. Further investigations of the multilayer packaging using infrared spectrometry and microscopy were able to determine specific multilayer characteristics such as typical layer numbers, average layer thicknesses, the polymers of the outer and inner layers, and typical multilayer structures for specific packaged goods. This dataset shows that multilayer packaging is mainly selected according to the task to be fulfilled, with practically no concern for its end-of-life recycling properties. The speed of innovation in recycling processes does not keep up with packaging material innovations.

To improve the recycling quality of plastics packaging and achieve high recycling rates new identification and sorting technologies are required. Tracer-based-sorting (TBS) is an innovative identification technology based on fluorescent tracers and a corresponding detection unit. TBS can be considered a radical technology change towards a circular economy for plastics and to support sustainability as it has the potential to render several established sorting and/or recycling steps obsolete. This article shows which drivers and barriers are perceived by stakeholders with regard to the implementation of TBS in the market and how challenges are addressed responsibly in the early phases of the innovation process. Influencing external factors and framework conditions of TBS are identified and suitable business models for TBS in a circular economy are discussed. Further, practical recommendations on how to optimize technology and market development for TBS are provided. To obtain these results a mixed method approach of integrated innovation and sustainability analysis, external environment analysis (PESTEL analysis), and business model development approaches was chosen. The research results can be understood as a practical contribution towards a responsible and sustainable implementation of a radical technology-based innovation for a circular economy of plastics.

In Deutschland werden weniger als die Hälfte aller Kunststoffabfälle werkstofflich verwertet. Eine Option um die zukünftigen Recyclingvorgaben zu erreichen ist die Verwendung anorganischer fluoreszierender Markermaterialien. Dieser Tracer‐Based Sorting(TBS)‐Ansatz wird bereits zur PVC‐Mahlgut‐Sortierung eingesetzt. Auf Anti‐Stokes‐Fluoreszenz basierende Markierungsstoffe in ppm‐Konzentrationen schaffen ein System von Sortiercodes, das in Zukunft hochwertige Rezyklate ermöglicht. TBS wird für die Sortierung von Kunststoffverpackungen aus Haushalten entwickelt und getestet.

Recent years have seen an increasing interest in exploring alternative techniques to conventional grinding methods such as fragmentation by high voltage discharges. Although pulsed power has already been applied to break down complex composite materials, there is currently no systematic comparison between different types of discharge regimes such as electrohydraulic and electrodynamic fragmentation. The aim of this work is to present such a comparison based on the electrohydraulic and electrodynamic fragmentation of copper indium diselenide (CIS) photovoltaic modules for potential indium recovery. High voltage discharges are performed in a process vessel filled with demineralized water at ambient conditions. After fragmentation, individual fractions are weighed, milled and the indium content is determined by X-ray fluorescence (XRF). Both the electrohydraulic and the electrodynamic approach are suitable to efficiently separate thin-film photovoltaic composite material into its constituent layers. The separation result is not dependent on the voltage level, but only on the total pulse energy applied. Since the generation of discharges with higher voltages requires a higher investment into plant properties such as insulation and generator, a comminution at lower voltages, i.e., electrohydraulic fragmentation, is preferable to electrodynamic fragmentation at higher voltages. To reveal the specific strengths of the two processes compared here, further comparative work with different composite materials is required.

Compounding is the final processing step for quality adjustment and control before recycled thermoplastic polymer material can be introduced into production processes. Motivated by the need for higher recyclate shares, the research question is which quality problems recycling compounders are encountered in practice, where they occur, and which mitigation options might be reasonable. Therefore, an online survey with 20 recycling compounders based in Germany was conducted asking about typical processing steps and processed materials, test procedures for quality assurance, quality problems, and possibilities for reducing quality problems. Results show that compounders mainly name impurities and contaminations of the input material as challenging and the reason for quality problems. The study shows that the problems are not dependent on the material input type. Quality problems occur along the entire secondary value chain, with companies manufacturing components themselves being particularly affected. The composition determination of the input materials helps to minimize quality problems.