GREEN - Upcycling of recycled plastics for use in geotextiles

Key materials for infrastructure and environmental protection

Geotextiles are indispensable materials for numerous applications in key industries such as transportation, construction, water management, and mining. They stabilize soils, protect against erosion, facilitate drainage, and contribute to waterproofing. The market for geotextiles is growing steadily, driven by the rising demand for infrastructure projects necessitated by demographic trends and climate change. In particular, flood protection and adaptation to climate change are increasing the demand for durable and high-performance geotextiles. To date, these products have been manufactured almost exclusively from virgin plastics, as recycled materials often fail to meet the high requirements for mechanical properties, long-term stability, and processability.

Additives improve the quality of recycled plastics

In the “GREEN” project, we are collaborating with partner institutions to explore innovative approaches to using recycled plastics in geotextiles. The goal is to promote sustainability and circularity in production while simultaneously meeting the industry’s technical requirements. Various recycled material streams made of polypropylene (PP), polyethylene terephthalate (PET), and high-density polyethylene (HDPE) were investigated. These materials were further processed into nonwovens (PP, PET) and membranes (HDPE). Through the targeted addition of additives, the rheological properties of the recycled materials were adjusted to ensure good processability and sufficient mechanical stability. Long-term tests under thermal and hydrolytic conditions showed that the modified recycled materials exhibit high durability and are therefore suitable for long-term use in geotextiles.

Ecotoxicological safety

In addition to technical performance, the environmental compatibility of the materials is a key aspect of this project. Geotextiles often come into direct contact with soil and water, which is why it must be ensured that no harmful substances are released. Comprehensive tests were conducted to assess the ecotoxicological safety of the recycled materials. The results show that the recycled material streams examined do not release any environmentally harmful compounds, such as heavy metals or per- and polyfluoroalkyl substances (PFAS). Furthermore, no toxic effects on organisms such as Daphnia (water fleas) were observed.

Prospects for the circular economy:

Sustainability in key sectors such as construction and water management

The GREEN project demonstrates that, through the targeted use of additives, recycled plastics can be upcycled for demanding applications such as geotextiles. This opens up new prospects for the circular economy and helps reduce the use of virgin plastics. At the same time, it promotes sustainability in key sectors such as construction and water management, offering both environmental and economic benefits.

By combining technical performance with ecotoxicological safety, the solutions developed make an important contribution to the transition toward a circular plastics economy and to meeting the growing demands for sustainable products.

Project partners

We are carrying out this project in collaboration with partner institutions as part of the Fraunhofer Cluster of Excellence Circular Plastics Economy CCPE