Micro Surface Roughness of O-rings and Sealing Mechanism 2002-01-0662

The correlation between the micro surface roughness and sealability of O-rings was experimentally analyzed. We developed a SMLA (Seal Micro Leakage Analyzer) for observing the contact of micro asperities using a micro-prism glass plate, and a micro-leakage measurement device for O-rings. Using the SMLA, the contact of micro asperities of O-rings surfaces ranging from 1.6 microns to 16.3 microns was clearly visualized. We also measured the contact area and leakage amount at the same time, and studied the sealing mechanism. The visualized images of the contact area were analyzed by image processing. The results showed that the micro asperites on the O-ring surfaces were squashed elastically to form a band which sealed in the fluid.