PTFE a Star Among Plastic Gaskets and Seals

All gaskets and seals have strengths and weaknesses that make them well suited for some applications and poor choices for others.  However, not many materials are as adaptable as PTFE, which by itself has a number of strengths, and whose weaknesses can be at least partially remedied through the inclusion of fillers or modifications.

PTFE offers a number of performance advantages that has resulted in increased use as a gasketing material.  Among these are the material’s ability to repel water, excellent thermal insulation, excellent resistance to most chemicals, and ability to operate in temperature extremes: PTFE can be used in applications with temperatures as cold as -400 degrees Fahrenheit or as high as 500 degrees Fahrenheit.  PTFE also complies with strict FDA regulations, enabling the material to be used in the food and pharmaceutical industries.  However, PTFE is not a universal solution for all sealing needs, as it still has a number of drawbacks, including weakness to alkalis and susceptibility to creep or cold flow that can weaken the gasket over time.  Some competing products also offer even higher temperature resistances.

3 Primary Types of PTFE Available

PTFE gaskets and seals are available in 3 primary forms, with each form offering different strengths and resistances:

• Virgin PTFE - unaltered PTFE that provides the strengths listed above
• Filled PTFE - PTFE that incorporates a filler material (most commonly glass or graphite) during the manufacturing process. Filled PTFE improves compressibility and resistance to certain chemicals compared to virgin PTFE.
• Expanded PTFE - PTFE that is molecularly rearranged during the manufacturing process. The microstructure of expanded PTFE gives it equal strength in all directions, eliminating structural weaknesses.  Expanded PTFE possess all of the chemical resistances of virgin PTFE.

PTFE Can Be Paired with Other Materials to Improve Quality

To further improve the capabilities of PTFE gaskets, metals (primarily stainless steel) can be incorporated into the gasket during manufacturing.  Metal inserted PTFE gaskets, such as those sold by Garlock and PureFlex, offer higher resistances to cold flow and blowout. 

New PTFE Gaskets Entering the Market

Because of the many advantages of PTFE gaskets, a number of manufacturers have introduced new PTFE gasket and seal products.  For instance, in 2016 Hallite (Fenner) introduced an entire line of PTFE seals sold under its Armorlene brand, Garlock launched a new GYLON BIO-PRO PLUS PTFE gasket, and Lamons (TriMas) introduced its Matrix CPG corrugated PTFE gasket.

Research on the Gasket & Seal Market

For more information, see the Gasket & Seal Market in the US, 12th Edition industry study from The Freedonia Group.  This comprehensive report provides vital information on market environment factors such as pricing patterns and technology and product development.  In addition, the study includes analysis on the following:

• Supply & demand data
• Product outlook
• Industry composition
• Market share
• Mergers & acquisitions
• And much more

About the Author:

Kyle Peters is the Assistant Manager of the Machinery and Equipment Group at The Freedonia Group, where he works on studies related to the US and global machinery, appliances, and industrial components markets.