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The engineering of an improved performance PTFE crankshaft (IPPC) seal is a challenge in the pursuit of longer service life and reduced total cost of ownership in the vehicular industry. This paper briefly reviews from the authors’ perspective the evolution of laydown PTFE seal design and details the IPPC seal features along with bench testing performance data.

The development of PTFE-seals in lay-down-technology is changing rapidly from an empirical to a more sophisticated engineering approach, due to the use of e.g. Finite Element Analysis (FEA) for optimization of design parameters. FEA is a powerful engineering tool, but its results are only as reliable as the input data for the model and the material. Therefore material tests with a specific PTFE-compound are performed including creep and relaxation. Then an explaination for the ‘bell mouthing’ of the seal lip is given. Further on it is analyzed how some design parameters like seal thickness, length, and grooves influence the contact pressure distribution.

Technology for evaluating and studying the PTFE lay-down sealing element is improving. This paper compares and assesses advanced finite element modeling and measurement techniques for determining the radial load distribution of a PTFE lay-down sealing element and the effective axial contact distance on the mating surface.