PTFE FAQs
Here are some of the more commonly asked questions about products molded in PTFE resins. Visit our technical page for information about applications, or contact us directly if you have a specific question.
PTFE resins have excellent physical properties for a wide range of sealing applications. They are essentially chemically inert and have a wide operating temperature. They are pliable, yet resilient. They have a very low coefficient of friction.
Yes. Although we deal primarily with unfilled PTFE, we do stock some of the commonly used compounds such as fiberglass, carbon/graphite, and moly filled. We use only prime-grade, virgin resins in our operations. We do not use mechanical-grade or re-processed resins at any time.
Here are photos illustrating a packing with and without compressive force applied. Note the flaring action of the sealing edges.
Yes, for a nominal set-up charge. We do have size limitations, so please contact us with your requirements.
Yes. All of our standard packing ring series can be custom configured. Here are some examples:
Yes. Our unique process allows us to vary heights/thickness within limits. Please contact us.
Not all shapes and geometries are compression moldable, so be sure to contact us. Please see representative examples below.
Working pressures are highly application dependant: Is the seal static or dynamic? What is the surface finish on the mating parts? What is the operating temperature? The resin itself is non-porous so there will be very little leakage through the packing ring set itself.
The same issues apply as for pressure rating (see above). Tighten the available adjustments until a seal is acquired. Keep in mind the resin will cold-flow somewhat on initial assembly so some subsequent adjustments may be required.
PTFE is chemically inert, so it does not deteriorate with age or react with the environment. The working temperature range of the resin is so wide that storage at ordinary conditions over extended periods of time, will have no impact on its ultimate usage or application.
PTFE resin is compressed at room temperature in the solid state, not the liquid state, as is done with injection molded thermo-plastics. The process is similar to that of powdered metal (PM) technology. Consequently, during the filling the mold cavity stage, the resin does not readily flow around corners or into thin walls.
When a cavity is not filled uniformly, there is non-uniform compression, which results in non-uniform shrinkage during the sintering stage, ultimately yielding dimensional issues.