The Lead Center Fluid Power Industry in Schwalmstadt has developed PFAS-free seals for its customer Epiroc / Tests passed successfully
Just over a year ago, Freudenberg Sealing Technologies received its first request for PFAS-free seals for rock drills by Epiroc, a company manufacturing drilling equipment for tunnel construction and civil engineering, among other things. The rock drills are used underground to drill holes for explosives. “The seals were previously made of PTFE because this material has high media resistance, low friction and a wide temperature application range,” says Marco Schönwälder, Product Engineer, Lead Center Fluid Power Industry at Schwalmstadt.
The rock drills operate in a high-frequency range, they move very quickly in forward and backward motion – up to 140 Hertz – and also perform a rotary motion at 200 revolutions per minute. “The seals are exposed to a harsh climate underground and have to withstand extreme conditions such as temperature, pressure and vibrations when the machine is in operation,” Schönwälder says. “Based on the parameters, it didn’t look like it would be possible to manufacture seals from another material, such as Polyurethane, that would meet these requirements. But since Epiroc is one of our very important customers, we just went for it.”
The product developers decided to test the relatively new and PFAS-free material 98AU30500. The first prototypes were created and tested by Epiroc on the company’s own test field. According to Schönwälder, the FST seals easily achieved the intended service life of 1,000 hours. Epiroc started its tests with four seals in different dimensions and has now ordered twelve more dimensions produced by Freudenberg Xpress.
The potential is around 110,000 seals per year for various rock drill models. 10,000 seals are required for the production of new rock drills and 100,000 seals as spare parts. Due to the extreme requirements, the rock drills are regularly serviced after 1,000 working hours and the seals are also replaced.
