Fluoropolymers like PTFE and FEP are widely known for their chemical inertness, low wettability, high-temperature resistance, and non-stick properties – qualities that make them popularly used across a wide range of industrial and medical applications. The actual Interesting Info about PFA vs FEP sv PTFE.
The goal of this study was to compare the performance of PFA, FEP, and PTFE fluoropolymer coatings after prolonged wear induced by brown corundum, glass microspheres, or plastic particles projected under pressure.
Cost
Fluoropolymers like PTFE, FEP, and PFA can be used to make corrosion-resistant products. Although commonly applied as coatings on metal surfaces, these polymers also add insulation and electrical resistance for high voltage wire and cable systems, as well as help prevent rusting of medical equipment and electronic components, as well as spacecraft performance by protecting against extreme temperature and space conditions.
PTFE, more commonly known by its tradename Teflon(tm), was one of the earliest synthetic fluoropolymers ever created, boasting low surface energy and excellent non-stick properties while being UV light resistant – qualities which make it perfect as mold release film release film release film material. Furthermore, its chemical resistance ensures it remains intact even after exposure to caustic chemicals or acids.
Another distinguishing characteristic of PTFE over other polymers is its ability to withstand extremely high temperatures, but this may become an issue under mechanical stress conditions. Due to its high melting point, PTFE may degrade and lose its integrity over time, rendering it unsuitable for specific applications.
FEP (fluorinated ethylene propylene), developed to overcome this limitation, allows heat forming, tipping, tapering, flaring, and flanging without difficulty. Like its parent material, PTFE, FEP boasts excellent chemical resistance as well as high-temperature tolerance.
Mechanical Properties
PFA (perfluorinated alkoxy) can be melt processed using conventional injection molding and extrusion techniques, boasting excellent impact strength, wear resistance, lower organic solvent permeability than PTFE, as well as improved flow, creep resistance, and thermal stability.
FePtFE boasts much higher tensile strength than FEP or PTFE, making it ideal for high-pressure applications. Furthermore, its highly flexible nature and good abrasion resistance make it suitable for high-pressure use. Again, its toughness can be increased through modification with glass fiber for an increase in toughness or stiffness; its operating temperature range stretches from -100 degC to 150 degC, allowing it to operate under conditions from extreme cold to heat exposure.
Teflon (PTFE) is produced through the free-radical polymerization of tetrafluoroethylene using special equipment, as this type of process tends to convert tetrafluoroethylene to toxic tetrafluoromethane with explosive side reactions. Once created, however, PTFE proves to be an exceptionally nonreactive material boasting superior abrasion resistance, creep and tensile strengths, and good elasticity properties.
PFA and FEP materials can be coated with thin layers of tetrafluoroethylene or perfluorinated alkoxy for corrosion protection, applying these coatings by spraying, wetting, or fluidizing bed and polymerizing into low-porosity films on substrates by polymerization. They’re resistant to chemicals, steam corrosion, and abrasion, as evidenced by scanning electron microscopy images of coatings showing they remain stable even under prolonged plastic particle abrasion. Figure 12 displays 3D topographic captures of samples after projection for 4, 8, and 12 seconds, with PFA showing only minor damage, while the PTFE coating has severe degradation with even visible substrate visible under its layers – even visible through.
Chemical Resistance
Fluoroplastics such as PTFE, FEP, and PFA are used in various applications due to their excellent temperature resistance and chemical stability. Each material enjoys different working temperatures, so you must select one that is appropriate to your application.
PTFE has earned itself the moniker “King of Plastics” thanks to its low friction coefficient, excellent chemical resistance, and non-reactivity. Furthermore, it’s one of the most formable fluoropolymers and can be easily molded to produce components, seals, and insulation – with an astounding maximum operating temperature of 260 degrees Celsius! PTFE comes in various forms, but the most popular ones include its milky white hue that provides increased visibility under fluorescent lighting conditions and its superior non-reactivity against chemical degradation by bacteria or virus threats.
Under medium-hard abrasive wear tests using brown corundum abrasive, PTFE demonstrated the least integrity, while FEP and PFA showed superior integrity levels under these conditions.
Scratch resistance was assessed in three coatings after 0, 4, 8, and 12 seconds of projection using an abrasive. Naked eye analysis was verified through 3D topographic captures using a Leica DCM8 high-definition microscope, and results indicated that PFA and FEP fluoropolymer coatings retained their integrity longer than PTFE coating. Over time, however, its integrity degraded completely, exposing its metal substrate – most evident during the 4 s test with scratch resistance dropping from 4.1 N to 1.5 N, revealing its metallic surface.
Heat Shrinkability
PFA is a TFE copolymer composed of perfluoropropylvinylether (PPVE). PPVE units disrupt TFE crystallization ability and lower crystallinity and melting point, making PFA melt processable, moldable via injection molding or screw extrusion techniques, and available as granular products suitable for molding/extrusion as well as powdered products that are used in rotational molding applications, rotational coating applications or semi-finished forms such as films sheets rods tubes, etc.
PFA provides excellent chemical, weather, and radiation resistance properties as well as electrical properties, with comparable tensile and flexural strengths to FEP. Furthermore, its resistance to thermal stress cracking surpasses that of its rival material.
Material has an optimal maximum working temperature of +260 degC while maintaining its flexibility at cryogenic temperatures, making it the perfect material for protecting sensitive equipment. In addition, its mechanical properties, good permeability resistance, and superior creep resistance make it an excellent choice.
PFA performed significantly better in shear abrasion testing than FEP and even PTFE in shear conditions, though after extended wear, both PFA and PTFE showed a loss of coating material as well as surface degradation visible via 3D captures of their surfaces – sometimes leaving substrates wholly exposed!
PFA far outperformed FEP and even PTFE in tests with plastic particles; shear abrasion combined with plastic deformation revealed significant degradation from both PFA and PTFE materials.
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