What are the main uses of polyethylene film?
Polytetrafluoroethylene (Polytetrafluoroethene), commonly known as "non-stick coating" or "easy-to-clean material"; is a synthetic polymer material that uses fluorine to replace all hydrogen atoms in polyethylene. This material is resistant to acid and alkali, and various organic solvents, and is almost insoluble in all solvents. At the same time, PTFE has the characteristics of high temperature resistance, and its friction coefficient is extremely low, so it can be used for lubrication, and it has also become an ideal coating for the inner layer of easy-to-clean woks and water pipes.
The film is made of suspended polytetrafluoroethylene resin through molding, sintering, cooling to form a blank, and then turning and calendering. The film formed by turning is a non-oriented film, and the non-oriented film becomes an oriented film after calendering. The non-oriented film is rolled 1.1-1.8 times to become a semi-oriented film. PTFE film is used as capacitor medium, as wire insulation, electrical instrument insulation, and sealing gasket. PTFE film is divided into PTFE color film, PTFE activated film and F46 film.
Performance characteristics of PTFE film
1. High temperature resistance: the working temperature can reach 250℃.
2. Low temperature resistance: It has good mechanical toughness; even if the temperature drops to -196°C, it can maintain an elongation of 5%.
3. Corrosion resistance: It is inert to most chemicals and solvents, and can withstand strong acids and alkalis, water and various organic solvents.
4. Weather resistance: It has the best aging life among plastics.
5. High lubrication: It is the one with the lowest friction coefficient among solid materials.
6. Non-adhesion: It is the smallest surface tension among solid materials and does not adhere to any substance.
7. Non-toxic: It is physiologically inert and has no adverse reactions when implanted as artificial blood vessels and organs for a long time.
8. Electrical insulation: can resist 1500 volts of high voltage.
The unique properties of polytetrafluoroethylene film (PTFE) make it widely used in industrial and marine operations such as chemical industry, petroleum, textile, food, papermaking, medicine, electronics and machinery. For example:
1. Application in electrical and electronic fields
The inherent low loss and small dielectric constant of polytetrafluoroethylene film (PTFE) materials make it possible to make enameled wires for micro motors, thermocouples, control devices, capacitors, radio insulation gaskets, insulated cables, motors and transformers Etc.; Utilizing the characteristics of fluoroplastics under high temperature and high pressure to produce poleward charge deviation phenomenon, microphones, speakers, parts on robots, etc. can be manufactured; using its low refractive index characteristics, optical fibers can be manufactured.
2. Application of anti-corrosion performance
Polytetrafluoroethylene film (PTFE) material has become the main corrosion-resistant material in petroleum, chemical, textile and other industries due to its excellent corrosion resistance. Its specific applications include: conveying pipes, exhaust pipes, steam pipes for conveying corrosive gases, high-pressure oil pipes for rolling mills, high, medium and low-pressure pipes for hydraulic systems and cold pressing systems, rectification towers, heat exchangers, kettles, towers, and tanks Linings, valves and other chemical equipment.
3. Application of low friction performance in load
Because the coefficient of friction of PTFE film is the lowest among known solid materials. Its specific uses include bearings for chemical equipment, papermaking machinery, and agricultural machinery, as piston rings, machine tool guide rails, and guide rings; in civil engineering engineering, it is widely used as a bearing for bridges, tunnels, steel structure roof trusses, large chemical pipelines, and storage tanks. Supporting sliders, and used as bridge bearings and bridging swivels, etc.
4. Application in medical medicine
The expanded polytetrafluoroethylene film (PTFE) material is purely inert, has very strong biological adaptability, will not cause rejection by the body, has no physiological side effects on the human body, can be sterilized by any method, and has a microporous structure, thus Can be used in a variety of rehabilitation solutions including artificial vessels and patches for soft tissue regeneration and surgical sutures for vascular, cardiac, general surgery and plastic surgery.
5. Application of anti-adhesive properties
Polytetrafluoroethylene film (PTFE) material has the smallest surface tension among solid materials, does not adhere to any substance, and also has excellent high and low temperature resistance, so that it is very suitable for applications such as anti-sticking in the manufacture of non-stick pans. widely. The anti-adhesive process mainly includes two types: installing PTFE parts or sheets on the substrate, and covering the substrate with PTFE coating or varnish composited with glass through heat shrinkage.
With the continuous development of material application technology, the three major shortcomings of polytetrafluoroethylene film (PTFE) materials: cold flow, difficult welding, and difficult melt processability are gradually being overcome, so that it is used in optics, electronics, medicine, The application prospects in various fields such as petrochemical oil transportation anti-seepage are broader.
