PTFE
| DESCRIPTION |
| PTFE is not a rubber compound though there are similarities. PTFE is a white thermoplastic resin capable of being formed into diverse shapes by either machining or molding. This premium grade material frequently is specified for harsh chemical environments in which rubber material is unsuitable, since PTFE is impervious to practically all gases and fluids. PTFE can withstand extreme high and low temperatures and has extremely low moisture absorption. It also offers the lowest coefficient of friction of any seal material. One issue with PTFE is that it can deform under a continuous load, which is frequently referred to as creep or cold flow. However, this behavior can be significantly counteracted by loading PTFE with fillers like graphite, bronze, glass, or molybdenum disulfide. PTFE also has relatively poor elasticity compared to other sealing materials. |
| COMPOSITION |
| Fluorocarbon resin generically known as polytetrafluoroethylene |
| PHYSICAL PROPERTIES* | Excellent | Good | Fair | Poor |
| Abrasion resistance | • | |||
| Compression set | • | |||
| Elongation | • | |||
| Flame resistance | • | |||
| Gas permeability | • | |||
| Low temperature flexibility | • | |||
| Tear resistance | • | |||
| Tensile strength | • |
| CHEMICAL RESISTANCE* | Excellent | Good | Fair | Poor |
| Impervious to most chemicals | • |
| OPERATING TEMPERATURE |
| -300 to 500 °F |
*Excellent, good, fair and poor serve as general guidelines only. Actual testing in the application environment is always recommended.
