Periodic Reporting for period 2 - Sol-Rec2 (Innovative digital watermarks and green solvents for the recovery and recycling of multi-layer materials)
Reporting period: 2022-12-01 to 2024-08-31
Plastics are an integral part of our daily lives, with 40% being used for packaging applications. In recent years, there has been increased pressure on the plastics industry to reduce plastic production and improve waste recycling. In 2018, improved waste management infrastructure and protocols for the efficient sorting of different polymer types led to the collection and recycling of 9.4 million tonnes of plastic post-consumer waste within the EU28. However, 7.2 million tonnes of plastic waste still ended up in landfill and, if we are to achieve the circular economy of plastics, zero landfilling will be necessary. The desire within the industry to minimise the quantity of plastics used in consumer packaging has led to ‘light-weighting,’ as in soft drink bottles using up to 50% less plastic while retaining the desired performance properties. However, light-weighting has led to the use of multi-layer materials that utilise smaller quantities of virgin materials but that are difficult to sort and recycle. These laminated materials are an increasingly popular option for lightweight packaging, with multiple thin layers being used. Laminates containing polyethylene (PE) and polypropylene (PP) are being increasingly used to store consumer products and such packaging often needs between 5 and 9 layers of different materials to provide the required properties. Similar combinations of materials are also found in medicine blister packs. Recycling of these materials is very important for society in terms of reducing pollution and conserving raw materials, as well as helping to adopt circular economy approaches. The ambitious objective of Sol-Rec2 was to develop and implement innovative sorting and recycling technologies for waste multi-layer food and medicine packaging that contained mixtures of plastics and metal. The project specifically focused on the treatment of:
• pharmaceutical blister packaging waste which typically consists of a mixture of PVC/aluminium
• laminated consumer packaging pouches comprising mixtures of plastics and aluminium
• pharmaceutical blister packaging waste which typically consists of a mixture of PVC/aluminium
• laminated consumer packaging pouches comprising mixtures of plastics and aluminium
The Sol-Rec2 team pursued a two-pronged approach to tackle multilayer plastic packaging waste: development of novel sorting techniques based on digital watermarks to facilitate efficient separation, and the selection and performance testing of a range of ionic liquids and deep eutectic solvents to prepare a toolbox of novel green solvents able to delaminate multi-layer materials. Combined, these enabled the efficient separation and recovery of individual types of polymers and aluminium. At the end of the project, both these key objectives had been successfully demonstrated, resulting in the separation and recovery of various polymers, aluminium and other materials suitable for ongoing treatment and reuse. New products were manufactured using the recycled polymers. The economic and environmental viability of the process was also assessed using life cycle-based methodologies, including a comparison with existing end-of-life approaches such as landfilling and incineration. Sol-Rec2 aimed to ultimately enable large-scale production of high purity plastics and aluminium for reuse in new applications. The new technology will provide recyclers with a valuable income stream, while also minimising the environmental impact and carbon footprint and making a valuable contribution to the circular economy.
In order to assess the opinions of the public about their attitudes towards multi-layer packaging and recycling, a detailed survey was prepared and distributed, mainly in countries across Europe. Several thousand responses were received. These have provided useful feedback that helped to inform and guide the specific broader activities of the Sol-Rec2 project.
The project team was also proactive in disseminating the project and its objectives at numerous events across Europe and further afield, including trade shows, exhibitions, and conferences. There was close liaison with others working in related areas and the team also engaged in European clustering activities to help promote and leverage their technology, while building networking synergies. Additionally, a video highlighting the project and its objectives was created and is available on YouTube.
In order to assess the opinions of the public about their attitudes towards multi-layer packaging and recycling, a detailed survey was prepared and distributed, mainly in countries across Europe. Several thousand responses were received. These have provided useful feedback that helped to inform and guide the specific broader activities of the Sol-Rec2 project.
The project team was also proactive in disseminating the project and its objectives at numerous events across Europe and further afield, including trade shows, exhibitions, and conferences. There was close liaison with others working in related areas and the team also engaged in European clustering activities to help promote and leverage their technology, while building networking synergies. Additionally, a video highlighting the project and its objectives was created and is available on YouTube.
The project progressed well beyond the current state of the art as the new Sol-Rec2 technologies enable the plastics and aluminium in waste multilayer packaging to be individually separated, recovered and recycled. Currently, this is often impossible. Two essential novel technologies have successfully been developed during the project, namely digital watermarks and the use of ionic liquids/deep eutectic solvents for delamination. The digital watermark utilises innovative codes embossed into or printed on packaging materials. These are unique identifiers that enable improved sorting of post-consumer multi-layer packaging waste, while also providing certain traceability of plastic products used for recycling. The ionic liquids/deep eutectic solvents are ‘green’ and have been used for separating the individual materials in multilayer packaging through fast and efficient delamination. The combination of these two technologies enables high purity materials (both polymer and aluminium) to be produced and reused. During this work the consortium compiled a toolbox of novel ionic liquids and solvents capable of selectively dissolving, delaminating, and separating the targeted components from multi-layer and multi-component materials. Many of these have been evaluated and found suitable as solvents for the dissolution and/or separation of PVC, PE and PP. Additionally, it is expected that the library will be used post-project to identify additional solvents for the recovery of other polymers and precious metals from a wider range of waste streams such as end of life electronics.
At the end of the project, the key results include defined and demonstrated processes for the;
• Delamination and recovery of PVC and aluminium from pharmaceutical blister packs. This includes optimisation, scale up and validation of the specific processes,
• Delamination and recovery of PE, PP and aluminium components from multilayer food packaging,
• Use of digital watermarks for identifying the material compositions of various types of multi-layer packaging enabling improved sorting.
The Sol-Rec2 technology’s widespread adoption promises positive socio-economic impacts, a reduced carbon footprint and contributions to the circular economy. By enabling the reuse of materials, Sol-Rec2 can also help reduce waste sent to landfill or incinerators, contributing to the EU’s ambitious goal of achieving 100 % plastic packaging reuse, recycling, and/or recovery by 2040.
At the end of the project, the key results include defined and demonstrated processes for the;
• Delamination and recovery of PVC and aluminium from pharmaceutical blister packs. This includes optimisation, scale up and validation of the specific processes,
• Delamination and recovery of PE, PP and aluminium components from multilayer food packaging,
• Use of digital watermarks for identifying the material compositions of various types of multi-layer packaging enabling improved sorting.
The Sol-Rec2 technology’s widespread adoption promises positive socio-economic impacts, a reduced carbon footprint and contributions to the circular economy. By enabling the reuse of materials, Sol-Rec2 can also help reduce waste sent to landfill or incinerators, contributing to the EU’s ambitious goal of achieving 100 % plastic packaging reuse, recycling, and/or recovery by 2040.