Everyone says that the king of plastics is Teflon, so what is Teflon?
First of all, Teflon is not a material, it is a family, just like the nylon family! With my experience in engineering plastics for more than ten years, I will briefly summarize Teflon!
1. Origin of Teflon: At first, Teflon in a narrow sense (Teflon: Chinese translation homophonic Te Iron F Fluorine Lon Dragon) was a trademark of DuPont, used for a series of fluoropolymer products based on polytetrafluoroethylene (PTFE). Polytetrafluoroethylene is a synthetic polymer compound formed by the polymerization of tetrafluoroethylene and is known as the "King of Plastics" for its excellent performance. Nowadays, in the broad sense of Teflon, when we talk about Teflon, we are actually discussing other related fluoroplastics in addition to polytetrafluoroethylene (PTFE), that is, plastics with fluorine (F)! Including PTFE (polytetrafluoroethylene), ETFE (ethylene-tetrafluoroethylene copolymer), FEP (fluorinated ethylene propylene copolymer), PFA (perfluoroalkyl compound) and PVDF (polyvinylidene fluoride) are all fluoroplastics, that is, polymer materials containing fluorine atoms, which have their own characteristics in chemical structure, physical properties and applications.
2. According to chemical structure and performance, Teflon materials can be divided into the following main categories: PTFE (polytetrafluoroethylene): the most classic, with excellent heat resistance, and can withstand high temperatures above 260°C. The surface is extremely smooth and non-sticky. The mechanical strength is relatively low, the hardness is large, and it is brittle. It is difficult to process and cannot be melt-molded. Compression molding or paste extrusion is commonly used. It is widely used, ranging from non-stick coatings for cookware to chemical pipelines.
ETFE (ethylene-tetrafluoroethylene copolymer): It has better strength and toughness than PTFE and can withstand greater mechanical stress. It is resistant to chemical corrosion and has good transparency. It can be processed by welding and is suitable for large structures such as membrane structures. It has good weather resistance and long outdoor service life.
FEP (fluorinated ethylene propylene copolymer): transparent or translucent, with better flexibility than PTFE. Can be melt processed, easy to weld, suitable for complex shaped products. Excellent chemical resistance, wide operating temperature range. Applications include wire insulation, chemical container lining, etc.
PFA (perfluoroalkoxy resin): performance close to PTFE, but better processability, can be melt processed. Stable at high temperature, chemical corrosion resistance, transparent or opaque. Strength and wear resistance are better than PTFE, suitable for high performance occasions. Applied to semiconductors, chemical equipment and medical equipment, etc.
PVDF (polyvinylidene fluoride): relatively low cost, good chemical resistance, but not as good as other fluoroplastics. Excellent weather resistance and UV resistance, often used in outdoor coatings. Good insulation and heat resistance, can be used as wire and cable sheath. It has a certain degree of flexibility and good processability, and can be molded by extrusion and injection molding.
In addition to the above main categories, there are some other fluoropolymers, such as ECTFE (ethylene-chlorotrifluoroethylene copolymer) and THV (copolymer of trifluoroethylene, hexafluoropropylene and vinyl ether), which are also part of the Teflon family. 3. Teflon application, how to choose the right Teflon material? Each Teflon material has its specific physical and chemical properties and is suitable for different applications. When choosing a Teflon material, it should be decided based on the specific performance required and the application environment. For example, PTFE is suitable for high temperature and chemical corrosion environments, while FEP and PFA may be more suitable for occasions that require good mechanical properties and easy processing.