The goal of the partnership is to ascertain the optimum surface roughness for HVOF sprayed coatings for Freudenberg’s entire range of seal setups.
Griekspoor has been working in partnership with Freudenberg for two years. The goal of the partnership is to ascertain the optimum surface roughness for HVOF sprayed coatings for Freudenberg’s entire range of seal setups. A T20 is shown in the example after having travelled 200kms in a worst case situation. No leakage of the seal was detected and wear on the seal was reduced to a minimum, if any.
The rod coatings, that were finished to varying roughnesses, show no wear or damage in worst case situations, having travelled over 5.000kms over all kinds of Freudenberg seals. Roughness values of the rod coating were unaffected over the entire duration of the test. Unaffected roughness values are very important, because it means that the tribological properties of the coating are equal over the lifespan of the seals. Stick-slip problems do not appear even when the seals reach the end of their life. When replacing the seals, the coating surface may be treated as a new coating surface.
The optimum coating roughness is different for different seals. When the required or recommended coating roughness is known, Griekspoor can “tune” the surface of the coating to that roughness. Test results are planned to be released coming month.