Improving Waste Plastic Sorting with Timegated® Raman Spectroscopy

Research demonstrates improved classification of challenging waste plastics containing brominated flame retardants

Efficient plastic recycling depends on accurate material identification and sorting. However, waste plastics from electrical and electronic equipment (WEEE) are often difficult to classify due to complex material compositions, additives and the presence of brominated flame retardants (BFRs), which can impact recycling quality and safety.

A recent peer-reviewed study explored how Timegated® Raman spectroscopy, combined with active hyperspectral sensing (AHS), can improve the classification of challenging waste plastic streams containing brominated flame retardants. The research focused on plastics sourced from waste electrical and electronic equipment, including dark and compositionally complex materials that are often difficult to analyze using conventional approaches.

The researchers analyzed over 200 waste plastic samples from real WEEE streams and laboratory-prepared reference materials. Timegated® Raman was used alongside near-infrared (NIR) hyperspectral sensing, while machine learning models classified plastics according to bromine concentration levels relevant for recycling and regulatory compliance.

The results showed that combining Raman and hyperspectral sensing data significantly improved classification performance, achieving over 80% balanced classification accuracy and outperforming single-sensor approaches. The findings demonstrate the potential of Timegated® Raman to support more reliable plastic waste sorting and material characterization in recycling processes.

Why does this matter for industrial recycling?

Reliable identification of waste plastics is essential for improving recycling efficiency, increasing material purity and supporting plastics circularity. Brominated flame retardants are commonly found in electronic waste plastics and require careful sorting to ensure recycled materials meet safety and quality requirements.

This study highlights how Timegated® Raman spectroscopy can contribute to solving one of the major challenges in plastics recycling: analyzing complex, additive-rich and difficult-to-classify materials. By enabling more reliable identification of challenging waste streams, Timegated® Raman supports smarter recycling and more sustainable material recovery.

Key takeaways

• Improved classification of WEEE plastic waste containing brominated flame retardants
• More reliable sorting of challenging and additive-rich plastic streams
• Enhanced performance through sensor fusion with Raman and hyperspectral sensing
• Over 80% classification accuracy achieved in the study
• Potential to improve recycling efficiency and plastics circularity

Read the original publication

Interested in the full methodology and results? Read the peer-reviewed publication:

Raman spectroscopy combined with active hyperspectral sensing for classification of waste plastics containing brominated flame retardants: A sensor fusion approach

Read via PubMed