Industry News

The Technical Challenge of Sorting In most recycling facilities, plastics are sorted automatically using near-infrared (NIR) sensors. This technology identifies materials by detecting light reflections in the infrared spectrum. Different types of plastics reflect light in unique ways, allowing the system to identify and separate them effectively. Black plastics often contain carbon black, which makes them challenging for NIR sensor systems to detect accurately and sort by type (PE, PP, ABS, etc.). As a result, carbon black plastics are typically removed during sorting, causing mixed fractions to be discarded as waste. Here are several reasons:

• Aesthetic: Black exudes a premium and timeless appeal.
• Color Coverage: Black pigments in plastic can conceal impurities or variations in material composition.
• Cost: Carbon Black is an affordable and effective pigment.
• UV Resistance: Black pigments, especially Carbon Black, offer excellent UV protection. They prevent premature aging, brittleness, or fading of plastics. Additionally, they protect the contents, as black packaging – like bottles – effectively blocks UV radiation. 
• The Impact on Recycling: The inability to reliably sort black plastics leads to several negative consequences:
• Lower Recycling Rates: Black plastics often go undetected, resulting in mixed batches being discarded or incinerated.
• Loss of Raw Materials: Valuable materials are lost instead of being reused in the cycle.
• Increased Environmental Impact: Incineration generates additional CO₂ and other emissions. Reduced Profitability: The purity and quality of usable material decrease, leading to lower selling prices.

Innovation: The Key to Material Detection

The good news: Promising methods already exist for recycling black plastics, such as using alternative color pigments or designing for recyclability. However, enhanced sorting technologies play a crucial role. Camera-based solutions will soon enable the reliable identification of even highly absorbent materials. Sesotec bridges a significant technological gap in plastic recycling by expanding its sensor portfolio with Mid-Wave Infrared (MWIR) technology. VARISORT+ sorting systems allow for the reliable detection and precise separation of larger black plastic pieces early in the recycling process, eliminating the need for sorting at the flake stage. What detection method is used With the introduction of Mid-Wave Infrared (MWIR) technology, Sesotec strategically expands its sensor portfolio to include a crucial wavelength range essential for reliably detecting black plastics.

A key advantage: The new camera-based technology integrates seamlessly into existing systems. Proven software, established algorithms, and existing AI models can continue to be utilized. This is all built on Sesotec's extensive experience in spectral analysis, ensuring secure and precise material classification. The result is a powerful comprehensive solution where innovative camera technology meets tried-and-tested evaluation methods – minimizing the risk of implementation.

Technology Overview

New wavelength range for reliable detection of black plastics Utilize existing software, algorithms, and AI models High classification accuracy through years of spectral analysis expertise Low implementation risk with proven evaluation methods MWIR technology is more than just a new sensor: it combines camera, lighting, intelligent software, and extensive application experience into a perfectly tailored solution for precise and reliable sorting of black plastics.

How does MWIR technology work? MWIR (Mid-Wave Infrared) leverages infrared radiation in the mid-wavelength range to identify materials by their molecular signatures.

Why it works for black plastics: Black plastics absorb visible light, leaving traditional cameras/NIR without reflections to capture In the MWIR range, plastics still exhibit distinctive absorption and emission spectra

How it works: Plastic is illuminated with infrared radiation. The material absorbs specific wavelengths, depending on its chemical structure. An MWIR sensor measures the reflected/emitted spectrum. Software compares the signal with known patterns. The type of plastic is classified (e.g., PE, PP, ABS). What's new or improved in technology The innovation lies primarily in the camera technology (MWIR wavelength range) – its true power is unleashed when combined with established AI, software, and the new wavelength range. - Enhanced differentiation of highly absorbent carbon black plastics - Integration of AI & spectral analysis.

Meet Sesotec's team at Stand C125 or visit their website for more information.

About

Join us on 17–18 June 2026 at Messe Frankfurt, Germany, for the industry’s most influential gathering of recycling companies, critical raw material suppliers, electronics and battery manufacturers, and ITAD specialists. This free-to-attend exhibition and conference grants you the unique opportunity to gain access to 4 co-located shows: E-Waste World Expo, Battery Recycling Expo, Metal Recycling Expo, and ITAD & Circular Electronics Expo. 

The information within the copy was supplied by Sesotec.