PTFE has some desirable characteristics as a gasket material: It has excellent chemical resistance and good temperature resistance. However, as a thermoplastic polymer, it has some very poor characteristics as well.
The biggest drawback to PTFE in a gasket application is that it “cold flows” or continually deforms under load (this condition is also known as “creep relaxation”). As a result, in time flange bolts must be re-torqued – especially if the process temperature fluctuates.
Garlock’s Gylon® Filled PTFE manufacturing process reorients the PTFE and fillers in a way that increases the material’s tensile properties and decreases the creep relaxation problems that usually plague PTFE products. In addition, the mixing process creates a homogenous material with consistent, superior physical properties that, unlike inferior skived PTFE sheet gaskets, do not fluctuate from one side of the sheet to another.
Garlock also manufactures a PTFE based gasket material that is not filled, but fibrous (ePTFE). This material offers excellent sealability and has very good resistance to creep relaxation. Not sure which material is the best for your application? Contact us!