Polytetrafluoroethylene or PTFE, with its carbon chains completely fluorinated is inert to an exhaustive range of industrial chemicals. It’s non-stick characteristic, which resists the build up of deposits, reduces clogging problems and is better for handling sticky resins and foodstuffs. Generally, limitation for use is molten alkali metals (such as metallic sodium), fluorine and the strong fluorinating agents.
Perfluoroalkoxy or PFA is a perfluoropolymer, which has essentially the same chemical resistance as PTFE has added moulding properties ideal for lining complex shapes. PFA is extensively used in Ultra-Pure applications. It has excellent creep resistance at high temperatures with good flame resistance and reasonably tough at low temperatures. PFA can be used in combination with PTE lined pipe for handling most chemical fluids.
POLYVINYLIDENE FLUORIDE (PVDF)
Polyvinylidene Fluoride, or PVDF is a crystalline fluorinated polymer, which is able to resist most inorganic acids and bases such as aliphatic and aromatic hydrocarbons and particularly for the halogens, bromine and chlorine. Its better elongation property is suitable for thermal cycling up to its temperature limit. PVDF has good abrasion and permeation resistance but being partially fluorinated, its chemical resistance is limited by temperature and concentration of the fluid.
POLYPROPYLENE COPOLYMER (PP)
Polypropylene Copolymer, or PP, is an inexpensive heat stabilise copolymer with good mechanical and chemical properties. It is ideal as a general purpose lining material for pipe, fittings and special fabrications normally used for water treatment, hot effluent lines, pickling and plating.
ETHYLENE TETRAFLUOROETHYLENE (ETFE)
Ethylene Tetrafluoroethylene or ETFE is a fluorine-based high performance coating that is designed to provide high resistance to corrosion. It has a very high melting point with further excellent chemical and electrical properties. ETFE at operating temperature (from -185°C to 150°C) are used in full vacuum because of the excellent adhesion to the wall of the coated piece.