Collecting & Sorting

Impact of colors in plastic recycling processes (NIR)

This research examines how the color of plastics, particularly dark colors and the additives used to create them, affects sorting during recycling. Dark pigments, such as carbon black, tend to absorb a significant portion of Near-Infrared (NIR) light, modifying how the material reflects the signal. This makes it harder for NIR-based systems to detect the specific polymer type. As a result, sorting becomes less accurate, leading to contamination in recycled plastic streams. This research is highly relevant for recyclers, packaging manufacturers, policymakers, and designers.

High-throughput screening of WEEE recyclate clusters

This research focuses on the rapid screening of post-consumer plastic recyclates to assess polymer purity and melt flow behavior, which are key factors for ensuring material quality suitable for mechanical recycling.

To achieve representative analysis, each bulk fraction is first shredded, mixed, and homogenized into single-sample specimens via small-scale extrusion, effectively ensuring that a single sample accurately represents the bulk-scale composition. After, composition and melt-flow behavior are characterized using several analytical techniques: ash testing to determine inorganic content, Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance (FTIR-ATR) and Differential Scanning Calorimetry (DSC) to identify polymer composition and thermal properties, and small amplitude oscillatory (SAOS) rheological measurements to evaluate melt viscoelastic behavior.

This screening protocol provides efficient and quick evaluation of recyclate properties, enabling insights for improving sorting strategies and recyclate quality. This research is highly relevant for recyclers, material developers, process engineers, and policymakers.

Do you have specific questions about Collecting & Sorting, part of the Knowledge Hub within the INCREACE project? Get in touch with our project manager: