Extrusion International 5-2025

73 Extrusion International 5/2025 ambitious Packaging and Packaging Waste Regulation (PPWR). These regulations have not only increased the required recycled content thresholds in beverage bot - tles, but are also setting targets for packaging beyond bottles, prompting tray manufacturers to seek new, dedicated sources of recycled PET. Despite its potential, tray-to-tray recycling presents several challenges today. PET trays often feature com- plex designs, including multilayer structures, inks, ad- hesives and labels, which complicate sorting and de- contamination. Unlike bottles, trays tend to be less standardized in shape and composition, making au- tomated identi cation and separation more dif cult. Contamination – such as food residues or embedded foreign materials – can further hinder sorting precision, especially once trays are compressed into bales. Collection infrastructure remains a major bottleneck. While PET bottles bene t from well-established deposit return systems and high collection rates, trays are often collected with mixed packaging or not at all. Further- more, the technology for sorting PET trays into a sepa- rate, dedicated fraction is not yet a standard practice, unlike with bottles. This often results in collected trays being lost within the mixed PET fraction or the general residue stream. This inconsistent feedstock quality and limited availability signi cantly increase the cost and complexity of producing food-grade recycled PET from trays. The industry is responding to the complexities of tray- to-tray recycling with increasingly sophisticated innova- tions. Advanced sensor-based sorting systems now play a central role in enabling high-quality recovery of PET trays. Traditional NIR systems like TOMRA’s multifunc- tional AUTOSORT™, for instance, are able to differenti- ate between mono-layer and multi-layer PET trays. This distinction is vital because only mono-layer trays are suitable for high-quality, closed-loop recycling. Some of the most signi cant developments are tak - ing place at the ake level, where sorting technologies are deployed to target a broad range of contaminants. Equipped with multi-sensor con gurations, these ma - chines can simultaneously detect akes by polymer type, color, transparency and material aging. This level of precision is essential for removing substances such as PVC, metals, and opaque particles. Once trays are shredded into akes, TOMRA’s INNO - SORT™ FLAKE system uses fast, intelligent sorting to accurately separate materials based on polymer type, color and transparency. Its high-speed capabilities ef - ciently remove common contaminants such as opaque PET, PVC, PC andother unwanted particles, minimizing material loss while laying the groundwork for an ultra- clean output. Building on this foundation, AUTOSORT™ FLAKE re- nes the ake stream even further. This high-end ap - plication system delivers exceptional accuracy at the n - est levels of detection and is even capable of detecting metals and multilayers. Using multifaceted sorting tech- nologies, it handles complex impurities that could oth- erwise degrade quality. The combined effort of these two sorting stages is an essential tool for manufactur- ers aiming to meet the stringent requirements of food- contact packaging. Some facilities operate dual sorting lines for clear and colored PET fractions, using ake-level detection to en - able continuous, exible production. By achieving pu - rity levels of 99% and above, these systems can allow recyclers to meet the rigorous benchmarks required for food-grade applications, while boosting yield and expanding the range of recycled content, such as trays suitable for microwave use. Tray-to-tray recycling draws material from both post- consumer and post-industrial sources – each offering distinct advantages and challenges. Post-industrial waste, such as offcuts from thermoforming lines or re- jected batches, typically features clean and homoge- neous PET, making it ideal for direct reprocessing. In contrast, post-consumer trays recovered through mu- nicipal collection systems are more variable in compo- sition, often containing multi-layer designs, labels and residual contamination. Despite these complexities, post-consumer recycling is critical for scaling circularity at the consumer level. PET trays often feature complex designs and composition which complicate sorting and decontamination In tray-to-tray recycling, ake-level sorting targets a wide range of contaminants