Conventional seals containing PTFE could soon be a thing of the past. A seal manufacturer from Germany has developed a new PFAS-free high-performance material that is already being used in the construction machinery industry.
The material is a hydrolysis-resistant high-performance polyurethane that offers better properties for mobile hydraulic sealing systems than conventional PTFE variants.
"PTFE materials do have high media resistance, a broad temperature spectrum for hydraulic applications and are low-friction as well as reliable," says Dr Jürgen Hieber. "However, our material 98 AU 30500 can top that, because it is extremely wear-resistant and also highly media-resistant.
Due to the optimised matching of material and geometry, our seals made of 98 AU 30500 have low friction, very low gap extrusion and thus a long service life. With excellent friction and sealing behaviour, such seals replace conventional PTFE seals for standard hydaulic application conditions. In addition, it can be used from -25 degrees to +120 degrees," says the head of materials development at Freudenberg Sealing Technologies.
Pilot applications in construction machinery
With the "OMK-PU 30500" piston seal, the sealing technology manufacturer has a new application with the innovative material in its portfolio that is particularly interesting for customers from the construction machinery sector. This two-part piston seal made of the hydrolysis-resistant high-performance polyurethane, combined with an O-ring contact element, is a real alternative to conventional piston seals with PTFE sliding ring.
"Because the piston seal is injection moulded, it is very cost effective. It is interchangeable with seals for standard PTFE ISO installation spaces and recalibration, i.e. bringing it to the correct dimension, is not necessary after installation. It has low friction and is excellent for extreme environments. It is also very robust against damage, even during assembly. Furthermore, the tightness is significantly increased compared to PTFE seals," Martin Goerres, Head of Engineering & Innovation at Freudenberg, describes the many advantages.
Market for PFAS-free seals is growing
Martin Goerres sees many other possible applications. In the first place, the material was actually developed for mobile hydraulic applications in the construction machinery sector in regions with high humidity. But in the meantime there have also been the first enquiries from customers in the food and packaging industries, for example. It is foreseeable that the market for PFAS-free sealing alternatives will continue to grow.
The predicted market growth is also due to the fact that the new material also represents an alternative to the perfluorinated and polyfluorinated alkyl substances (PFAS) that have come under criticism. The high-performance material offers users an alternative that complies with strict legal requirements. "At the same time, the new material is also an important step for us to achieve our own sustainability goals," explains Goerres.