PTFE – Polytetrafluoroethylene
PTFE has a famous trade name, which is Teflon ® produced by DuPont. Virgin PTFE is a white, waxy feeling industrial plastic and has almost universal chemical resistance. It is the first fluorocarbon and only reacts to a few chemicals. Compared to other engineering plastics, its mechanical properties are low, but it is useful over a greater temperature range, from-240 to 260°C. PTFE has excellent thermal and electrical insulation properties as well as a low coefficient of friction. One of its characteristics is that it is difficult to make anything adhere to PTFE. Even if a material may stick to it, it usually can be peeled off or rubbed off. PTFE is the only known surface to which a gecko cannot stick. Companies such as Loctite and 3M have developed specialist acrylic based adhesives that bond directly to PTFE with no need for pre-treatment other than a preliminary solvent wipe. PTFE can be moulded into solid rods, tubes and sheets for machining into finished components. It also has excellent UV resistance. High loads and compressive forces can easily deform PTFE in its virgin form. To minimise this, additives such as glass, bronze, or carbon are added prior to moulding. PTFE can also be chemically etched on one surface to allow bonding to steel surfaces. The most common food grade use of PTFE is DuPont’s Teflon® lining for cookware.
- Long life electrets
- Plain bearings
- Cryogenic applications
- Graft material in surgical interventions
- Pipework for reactive chemicals