Rotary shaft seal applications, ranging from wind energy to automotive seals, require reliable performance in often challenging environments. To meet the challenges, filled-PTFE is often the material of choice for the seal lip. But which type of PTFE will work best for your application? In this week’s blog post, we will go over the various types of PTFE used in rotary shaft seals, their pros and cons, and what type of PTFE is best for you.
Evolution of Seal Materials
The evolution of seal materials evolved as seals faced more rugged demands. Early needs could be met using packed hemp or leather, but as the demands became more and more rigorous new materials were sought. This led to the introduction of natural rubber seals, which evolved into synthetic elastomers, and finally engineering polymers like PTFE (Polytetrafluoroethylene).
Four of the most common modern material options for rotary shaft seal lips are nitrile rubber, polyacrylate, FKM, and PTFE. Of these materials, three are elastomers nitrile rubber, polyacrylate rubber and FKM and only one is polymer PTFE. Lets see how these materials stack up.
Want more about PTFE? Check out these artiicles from the popular Advanced EMC Technologies blog:
- PTFE Spring-Energized Cryogenic Seals Revisited
- Rotary Seals for Dummies: Four Questions about Shaft Surfaces for PTFE Rotary Seals
- What is Polytetrafluoroethylene (PTFE), a flash of genius or a lucky accident for mankind?