The combined strength, thermal, and chemical properties of polyetheretherketone make it an excellent choice for high temperature, environments in need of bushings. Add to that its ability to serve as an excellent replacement for metal bushings, and its ability to have its properties further enhanced by additives like glass and carbon, and PEEK quickly stands out as a top choice for high-performance polymer bushings.
Tags:PEEK,High-Performance Bushings
The PTFE Rotary Seal Difference
PTFE rotary seals are often the answer when elastomeric seals just can’t handle the demands. In this article we are going to look at just five ways that PTFE seals differ in performance and behavior from elastomeric seals.
Here are some additional blog posts from the Advanced EMC Technologies Blog:
• Out of Whack: Eccentricity and Runout in PTFE Rotary Seals
• PTFE Rotary Lip Seals - 6 Feature Competitors Don't Want You to Know!
• Rotary Seals for Dummies: Four Questions about Shaft Surfaces for PTFE Rotary Seals
Low Friction
Because of the incredibly low coefficient of friction that PTFE has, it can be used in applications where lubricant cannot be used. This is referred to as “dry running,” and PTFE seals excel in these types of applications where elastomeric seals fail.
Speed
Because of the low friction and excellent wear capabilities of PTFE, most PTFE seals can withstand running speeds of up to 5,900 feet per minute, or 30 m/s. This makes them ideal for speed-intensive applications where reliable sealing is vital.
Chemical Compatibility and FDA Approval
PTFE is known for its incredible compatibility with a variety of chemicals, which sets it apart from the elastomeric materials typically used in sealing applications. Many PTFE compounds already FDA approval and are commonly used in pharmaceutical, food, and dairy applications
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Operating Temperatures
Another benefit of PTFE rotary seals over traditional elastomeric rotary seals is the temperature range over which they can operate. Most PTFE seals can perform in the cryogenic temperatures all the way down to -95°F up and up to extremely high temperatures of 480°F.
Relationship between Speed and Friction
The hydrodynamic film all the separates the seal lip from the movie.How much friction exists between the seal and the sealing surface is a function of the thickness of the hydrodynamic film. The film pulled into the gap between the seal and the surface by viscous drag. When the shaft is at rest, this layer will be at its minimum thickness and a certain amount of torque will be required to overcome the initial resistance to motion. Friction decreases as the velocity increases up to a point; after that speed is reached, friction will again begin to rise and the seal may begin to experience wear. However, PTFE has a very low coefficient of friction to begin with, and may often be an exception to this rule.
PTFE Seals Alternative
The next time you are choosing a dynamic seal for an application that involves high speeds, extreme temperatures, a need for low friction, FDA approval, or chemical resistance, don’t forget to look into PTFE seals as an alternative to the traditional elastomeric dynamic seals.
For more detailed information on PTFE Rotary Shaft Seals download Advanced EMC Technologies resource guide.
Tags:rotary seal,ElaomstericSeals,ptfe
Teflon is the Chemours (Wilmington, DE) brand name for polytetrafluoroethylene (PTFE). The material offers resistance to solvents and flames, a high melting point, strength and the non-stick properties that home cooks know well. A 2016 Zion Research (Pune, India) report projected that the global PTFE market, valued at $4 billion in 2014, would grow to $6.5 billion by 2020.
PTFE demand is rising as consumers buy more electronic products that use the material, according to Zion. The Asia-Pacific region comprised the largest market for the material in 2014, followed by Europe. Besides electronics, PTFE is found in automotive parts, chemical processing, textiles and medical products.
Medical uses of PTFE are booming, according to Bruce Nesbitt, founder and Chairman of Orion Technologies, a Chicago-based applicator of Teflon coatings. PTFE can coat a range of materials, a versatility that makes it useful on many medical devices. PTFE is increasingly found on products that incorporate handles or attachments that help clinicians manipulate the device, Nesbitt said. Devices that use PTFE include dental drills, guidewires that steer devices through the body and medical tubing.
“Any two components that slide together, such as a metal tube and plastic housing, can benefit from the Teflon coating on either or both sliding surfaces,” Nesbitt said.
The growing medical applications of PTFE led Orion to spin off a separate company called Surface Solutions Group. The firm can apply medical-grade coatings that further reduce friction, as well as incorporate antimicrobials to meet the sterility requirements of medical device makers. The more critical the end use, such as applications in aircraft and medical devices, the more stringent the test requirements, Nesbitt said.
“Medical, by far, is the tightest,” he said. “Military and aircraft is somewhat behind that . . . automotive is quickly bringing up the rear.”
Tags: PTFE,Teflon,Electronics, medical