Polymark, a collaborative three-year research project, has published its preliminary technical results for the development of food-contact approved chemical markers which it is hoped will improve identification and sorting of higher value elements, particularly PET, in the plastics waste stream.
“This 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. The technology can also be used for other purposes,” said the Polymark Consortium.
Patrick Peuch from Petcore Europe said that, following 18 months of work and a project review with the European Commission, which is funding the project, “Our research partners have successfully developed a complete technology package. By publicly 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.”
PET is widely recycled in Europe, but the potential for brand owners to use more food-contact rPET has been hampered by the mixing of food-contact types of PET with other types of PET, and with other polymers, in the waste stream.
In its first 18 months, the Polymark project has successfully developed a prototype, flexible, coating-based approach for marking PET bottles. The partners used commercially available, near UV-excitable markers with strong fluorescence in the visible region of the electromagnetic spectrum, which allowed them to develop high-speed detection technology with minimal UV/ozone generation hazards.
The markers are formulated in a water-based, sprayable coating to minimise use of VOCs (volatile organic compounds) which have associated flammability hazards.
The project has also demonstrated the markers can be removed following sorting so that marker accumulation and associated potential for false positive detection in the long term is minimised. The coating is removable under alkaline wash conditions already in use within recycling plants.
During the next 18 months, the Polymark project will focus on scaling up the technology to industrial conditions as well as on communicating the results and benefits to all potential users through workshops and training.
In this phase, “the coating-based marker system will be subjected to real-world environments, further testing and sorting efficiency trials and optimisation using the prototype detection/sorting equipment currently under development”, said Polymark.
An economic analysis and environmental impact study are also planned.
The Polymark partners include: Petcore Europe, European Federation of Bottled Waters (EFBW), European Association of Plastics Recycling and Recovery Organisations (EPRO), Plastics Recyclers Europe (PRE), UK Health and Environmental Research Institute (UK-HERI), Fraunhofer Institute for Photonic Microsystems (IPMS), Sesotec GmbH, ColorMatrix Europe Ltd and 4PET Recycling.
More information is available at www.polymark.org. The Polymark project will be discussed in a PET conference session at Plastics Recycling Show Europe, the new event being run by PNE's publisher Crain Communications in Brussels on 25-26 November. Find out more at www.prseventeurope.com.