Fraunhofer researchers have developed sustainable new seals that are free from environmentally harmful substances, such as PFAS, and are suitable for use with water-based lubricants. They will present their solution at the joint Fraunhofer booth (Booth 431, Hall A3) at Laser World of Photonics 2025, taking place from June 24 to 27.
From ship propellers to wind turbines and harvesters, seals are essential to ensuring the functionality of any technical system with moving parts. To increase their durability, they have mainly been made from plastics that contain PFAS and are maintained with petroleum-based lubricants. That is true across the many different places where they are used, from power plants to motor vehicles. Defects and damage, therefore, not only cause economic harm but can also have a substantial environmental impact because the lubricants and chemicals enter the environment.
“Known as ‘forever chemicals,’ per- and polyfluoroalkyl substances, or PFAS for short, accumulate in the environment, cannot be broken down and also pose health risks. The upcoming ban in the EU is putting the industry in an even tighter spot. Additionally, approximately one million metric tons of lubricants containing petroleum are used in Germany alone each year. A single litre can contaminate as much as a million litres of groundwater. This results in oily soils, contaminated food, and destroyed ecosystems. We set out to find a solution that addresses all of these challenges together,” said Matthias Trenn, head of the Surface Structuring team at the Fraunhofer Institute for Laser Technology ILT.
Forward-looking seals that benefit the environment
The project was a complete success. With funding from the Fraunhofer-Zukunftsstiftung (Fraunhofer Future Foundation), researchers at the Fraunhofer Institute for Laser Technology (ILT) and the Fraunhofer Institute for Mechanics of Materials (IWM) teamed up in the pureWaterSeal project to develop forward-looking seals that are not only PFAS-free but also suitable for use with water-based lubricants.
To accomplish this, the experts from Fraunhofer IWM, led by Manuel Mee, head of the Tribological Coatings team, developed diamond-like carbon (DLC) coatings designed for PFAS-free plastic components. In combination with laser structuring from Fraunhofer ILT, the researchers deliberately reduce internal tension and mechanical loading, not equally everywhere but locally at individual points instead. This maintains the structural integrity of the coating while optimising its functional properties, such as resistance to wear and reduced friction. The seals have significantly longer lifespans as a result. Combining the coating and microstructuring also makes it possible to use water-based lubricants, which was previously not feasible.
“The development of the seals is an important step in advancing eco-friendly production methods since PFAS enters the environment primarily during manufacturing and not as much in application. We are protecting resources and ecosystems by using exclusively non-harmful substances. At the same time, our seals are an optimum fit for even sophisticated functional challenges,” says Christof Koplin, head of the Polymer Tribology and Biomedical Materials team at Fraunhofer IWM.
Together for fast implementation
The Fraunhofer specialists work closely with partner companies, focusing on various applications, to ensure that their solution is quickly, successfully, and on the broadest possible basis adopted in industrial practice. Initial prototypes are already in use in pumps at geothermal power plants. The next goal is to transfer the process to larger facilities and systems and transition into series production. At the same time, research scientists are continually optimising their seals, targeting various areas of application and customer needs. Plans for a spin-off that markets these developments are already underway.
Attendees at Laser World of Photonics 2025, taking place from June 24 to 27, will have the opportunity to learn about the eco-friendly solution and its prospects. The researchers will present the results of their project at the joint booth of the Fraunhofer-Gesellschaft, located at Booth 431 in Hall A3.
