The Fraunhofer Institute for Laser Technology ILT is developing new laser-based manufacturing processes to apply PFAS-free functional coatings to wind energy industrial components.
Regulatory restrictions on PFAS (per- and polyfluoroalkyl substances) are growing, as harmful properties of the resilient materials continue to come to light.
Designed to be fire-proof and tolerate harsh operating conditions, PFAS takes these qualities through to the logical end stage of being extremely resistant to breaking down in the environment. This has led to knock-on negative health impacts on wildlife and even people through contamination in the water supply and food chain.
Resistant coatings are necessary for some machinery to function, but will require PFAS-free alternatives, as well as potentially new methods of application, which is where Fraunhofer ILT’s research comes in.
RePEEK and EPOS
Fraunhofer ILT is investigating laser-based methods to apply polyetheretherketone (PEEK) coatings as an alternative to PTFE-based systems. One potential application is large plain bearings used in wind turbines, where coatings help reduce friction between rotating shafts and bearing surfaces.
Conventional PEEK coating methods often require components to be heated in large furnaces, which can be energy-intensive and challenging for heavy components. The laser-based process developed by Fraunhofer ILT applies and melts the coating material locally, reducing thermal stress on the component while enabling controlled coating of large surfaces.
In the RePEEK project, researchers are developing a process in which a laser first creates a metallic surface layer to improve adhesion before PEEK powder is applied and melted into the structure. The resulting coating combines a metallic functional layer with a PEEK-based top layer.
The related EPOS project focuses on applying PEEK coatings in multiple layers to large plain-bearing components. The approach aims to achieve thicker coatings without requiring the complete component to undergo high-temperature furnace treatment.
Other projects are exploring PFAS-free alternatives for other types of machinery
Other Fraunhofer ILT projects are addressing PFAS-free coatings for elastomer rollers and sealing systems. The pureWaterSeal project, for example, combines PFAS-free sealing materials with water-based lubricants.
Researchers are using laser structuring of diamond-like carbon (DLC) coatings to reduce friction and improve wear resistance.
