Polymark, a three-year research project funded by the European Commission, has published the preliminary technical results of the research targeted at the development of a new technology that will enable the identification and sorting of polymers, including PET, in the high-value plastics waste stream. Stakeholders from the entire PET value chain are participating in the project in which food contact chemical markers are being developed that will help the recycling industry to more effectively distinguish between food-contact and non-food contact PET, while meeting EU regulation on the use of recycled PET for food-contact applications. This will enable the high-value waste stream to be further optimized, ultimately promoting a more valuable use of these materials.

Now that the first 18 months of the project have been weathered successfully, including a favorable project review with the European Commission in June, the Polymark consortium is ready to present the preliminary results. “Our research partners have successfully developed a complete technology package,” explained Patrick Peuch from Petcore Europe. “By publically releasing these results, in agreement with our Polymark Consortium and the approval of the European Commission, we aim to raise early awareness and to give unconstrained access to the widest number of interested parties for their faster consideration and longer-term planning.”

What has been achieved in the project thus far? According to the report, a predominantly food contact approved, coating-based approach for the addition of a fluorescent marker to PET bottles has been developed, in which commercially available, near UV-excitable markers are used with strong fluorescence in the visible region of the electromagnetic spectrum. These made it possible to develop a detection system with minimal UV/ozone generation hazards. Moreover, only low levels of marker were required for detection due to the strong fluorescence of the markers. A coating formulation was developed that was water-based and sprayable, to minimize use of VOCs with associated flammability hazards. Use of a coating approach had the added advantage that further, dispersible marker pigments to the coating formulation in combination to allow development of a coding system in the future.

The researchers were also able to demonstrate that the marker could be removed following sorting, to keep marker accumulation, and the associated potential for false positive detection in the long term, to a minimum. Detector technology suitable for high speed sorting was developed in parallel to the marking technology, and initial results in this area are also reported.

During the next phase of this project, the coating-based marker system will be subjected to real-world environments, further testing and sorting efficiency trials and optimization using the prototype detection/sorting equipment currently under development. Additionally, an economic analysis and environmental impact study are planned. The results of these activities will be reported in due course.

During the next 18 months, Polymark will focus on scaling up the technology to industrial conditions, as well as on communicating the results. An economic analysis and environmental impact study are also planned.

The Polymark partners include: Petcore Europe, European Federation of Bottled Waters, European Association of Plastics Recycling and Recovery Organizations (EPRO), Plastics Recyclers Europe, UK Health and Environmental Research Institute, Fraunhofer Institute for Photonic Microsystems, Sesotec GmbH, ColorMatrix Europe Ltd and 4PET Recycling.