PTFE is a **** polymer of ethylene and tetrafluoroethylene, the resin is the toughest fluoropolymer, which creates a highly durable coating with excellent chemical resistance and can be used for continuous work up to 150 degrees Celsius. It can be injection molded, extruded or made into coatings.
After Teflon coating, it has the following properties:
1. Non-adhesion:
Almost all substances do not bond with Teflon coating film. Very thin film also shows very good non-adhesive properties.
2, heat resistance:
Teflon coated film has excellent heat and low temperature resistance properties. It can withstand high temperature up to 300℃ for a short period of time, and generally can be used continuously between 240℃~260℃. It has remarkable thermal stability, it can work at freezing temperature without brittleness, and does not melt at high temperature.
3, sliding:
Teflon coating film has a low coefficient of friction. The coefficient of friction changes when the load slides, but the value is only between 0.05-0.15.
4, moisture resistance:
Teflon coated film surface is not stained with water and oil, and it is not easy to stain the solution during the production operation, such as a small amount of dirt, a simple wipe can be removed. Short downtime saves working hours and improves work efficiency.
5, wear resistance:
Under high load, it has excellent wear resistance. Under a certain load, it has the double advantages of abrasion resistance and non-adhesion.
6, corrosion resistance:
Teflon is virtually impervious to pharmaceutical erosion and can protect parts from any kind of chemical corrosion. Polytetrafluoroethylene is a polymer of tetrafluoroethylene. English abbreviation for PTFE. trade name "Teflon" (teflon). It is known as the "king of plastics". The basic structure of PTFE is. - CF2 - CF2 - CF2 - CF2 - CF2 - CF2 - CF2 - CF2 - CF2 - CF2 - CF2 - CF2 - CF2 -. Polytetrafluoroethylene is widely used in various applications that require resistance to acids, alkalis and organic solvents. It is not toxic to humans, but one of the raw materials used in the production process, perfluorooctanoic acid ammonium salt (PFOA), is thought to have carcinogenic effects. The relative molecular mass of polytetrafluoroethylene is large, with a low of hundreds of thousands, and a high of more than 10 million, generally millions (the degree of polymerization is on the order of 104, while polyethylene is only 103). General crystallinity of 90 ~ 95%, melting temperature of 327 ~ 342 ℃. Polytetrafluoroethylene molecule CF2 unit arranged in a sawtooth shape, due to the fluorine atom radius is slightly larger than hydrogen, so the adjacent CF2 unit can not be completely according to the trans cross orientation, but the formation of a helical twisted chain, fluorine atoms cover almost the entire surface of the polymer chain. This molecular structure explains the various properties of PTFE. At temperatures below 19°C, a 13/6 helix is formed; at 19°C a phase transition occurs and the molecules slightly unravel to form a 15/7 helix. It does not melt at temperatures of 250°C and does not become brittle at ultra-low temperatures of -260°C. Polytetrafluoroethylene is exceptionally smooth, even ice can not be compared to it; it is particularly good insulating properties, newspaper thick layer of film, will be enough to resist 1500V high voltage electricity. Polymerization Polytetrafluoroethylene is produced by free radical polymerization of tetrafluoroethylene. Industrial polymerization reaction is carried out in the presence of a large amount of water stirring, to disperse the reaction heat, and easy to control the temperature. Polymerization is generally carried out at 40 ~ 80 ℃, 3 ~ 26 kg force / cm 2 pressure, can be used inorganic persulfate, organic peroxide as an initiator, you can also use redox initiation system. Every mole of tetrafluoroethylene polymerization exothermic 171.38 kJ. dispersion polymerization must add perfluorinated surfactants, such as perfluorooctanoic acid or its salts. Applications Polytetrafluoroethylene can be molded by compression or extrusion; it can also be made into aqueous dispersions for coating, impregnation, or fibers. Polytetrafluoroethylene is widely used in atomic energy, aerospace, electronics, electrical, chemical, machinery, instruments, meters, construction, textiles, food and other industries as high and low temperature resistance, corrosion-resistant materials, insulating materials, anti-adhesive coatings and so on.
Edit Chemical Properties Insulation:
Independence of the environment and frequency, volume resistance up to 1018 ohm-cm, small dielectric loss, high breakdown voltage.
High and low temperature resistance:
Not much change to the influence of temperature, wide range of temperature domain, can be used at -190~260℃.
Self-lubrication:
With the smallest coefficient of friction among plastics, it is an ideal oil-free lubrication material.
Surface non-adhesion:
No known solid material can adhere to the surface, it is a solid material with minimum surface energy. Atmospheric aging resistance, irradiation resistance and low permeability: long-term exposure to the atmosphere, the surface and its properties remain unchanged
Non-combustibility:
Limited oxygen index of 90 or less.
Edit Physical Properties PTFE is mechanically soft. Has a very low surface energy. Polytetrafluoroethylene (F4,PTFE) has a series of excellent use of performance: high temperature resistance - long-term use of 200 ~ 260 degrees, low temperature resistance - still soft at -100 degrees; corrosion resistance - resistant to aqua regia and all organic solvents; weather resistance - the best aging life among plastics; the best aging life among plastics; the best aging life among plastics; the best aging life among plastics; the best aging life among plastics. The best aging life among plastics; high lubrication - with the smallest coefficient of friction among plastics (0.04); non-sticky - with the smallest surface tension among solid materials without adhering to any substance; non-toxic - with physiological inertia; excellent electrical properties, is the ideal C-class insulating material. Polytetrafluoroethylene materials, widely used in the defense industry, atomic energy, petroleum, radio, electric machinery, chemical industry and other important sectors. Products: Polytetrafluoroethylene rods, tubes, sheets, turned sheets. Polytetrafluoroethylene is a polymer of tetrafluoroethylene. The abbreviation is PTFE, the structure formula is. discovered in the late 1930s, and put into industrial production in the 1940s. Properties Polytetrafluoroethylene relative molecular mass is large, the low hundreds of thousands, high up to more than 10 million, generally millions (polymerization degree in the 104 order of magnitude, while the polyethylene is only 103). General crystallinity of 90 ~ 95%, melting temperature of 327 ~ 342 ℃. Polytetrafluoroethylene molecule CF2 unit arranged in a sawtooth shape, due to the fluorine atom radius is slightly larger than hydrogen, so the adjacent CF2 unit can not be completely according to the trans cross orientation, but the formation of a helical twisted chain, fluorine atoms cover almost the entire surface of the polymer chain. This molecular structure explains the various properties of PTFE. At temperatures below 19°C, a 13/6 helix is formed; at 19°C a phase transition occurs and the molecule unravels slightly to form a 15/7 helix. Although in perfluorocarbon compounds in the carbon-carbon bond and carbon-fluorine bond breaking need to absorb energy 346.94 and 484.88kJ/mol, but polytetrafluoroethylene depolymerization to generate 1 mol tetrafluoroethylene only need energy 171.38kJ. so in the high temperature cleavage, polytetrafluoroethylene is mainly decomposition to tetrafluoroethylene. The weight loss rate (%) of PTFE at 260, 370 and 420°C is 1×10-4, 4×10-3 and 9×10-2 per hour, respectively, which shows that PTFE can be used for a long time at 260°C. The high temperature cracking also produces a dramatic increase in weight loss. Since high temperature cracking also produces highly toxic by-products such as fluorine phosgene and perfluoroisobutene, special attention should be paid to safety protection and to prevent PTFE from contacting with open flames. Mechanical properties Its coefficient of friction is extremely small, only 1/5 of that of polyethylene, which is an important feature of perfluorocarbon surface. This is an important feature of the perfluorocarbon surface. Because of the extremely low intermolecular force between fluorine and carbon chains, PTFE is non-stick. ● Mechanical properties: Tensile strength σb (MPa): 20.7～27.5 Elongation δ5 (%): 250～350 Impact toughness value αk (J/cm2): with notch: ≥16.1; without notch: >98.1 Tensile modulus of elasticity (MPa): ≥3.92 Hardness: 50～65D ● Thermal properties: Heat distortion temperature: 1.86MPa:55℃. 0.46MPa:120℃; 0.46MPa:120℃ Martin heat-resistant temperature ：250℃ Continuous use temperature ：250℃ Flammability ：Self-extinguishing Polytetrafluoroethylene maintains excellent mechanical properties over a wide range of temperatures from -196 to 260℃, and one of the characteristics of perfluorocarbon polymers is that they do not become brittle at low temperatures. Chemical Resistance and Weather Resistance Except for molten alkali metals, PTFE is not subject to corrosion by almost any chemical reagent. For example, in concentrated sulfuric acid, nitric acid, hydrochloric acid, and even boiled in aqua regia, its weight and performance are unchanged, and almost insoluble in all solvents, only slightly soluble in all-alkanes at 300 ℃ or more (about 0.1g/100g). Polytetrafluoroethylene does not absorb moisture, non-combustible, extremely stable to oxygen, ultraviolet light, so it has excellent weather resistance. Electrical properties Polytetrafluoroethylene in a wide frequency range of dielectric constant and dielectric loss are very low, and breakdown voltage, volume resistivity and arc resistance are high. Radiation resistance PTFE radiation resistance is poor (104 rads), by high-energy radiation caused by degradation, the electrical properties of polymers and mechanical properties are significantly reduced.
Edit Applications PTFE's unique properties make it in the chemical, petroleum, textile, food, paper, medical, electronic and mechanical industries and marine operations have a wide range of applications.
1, polytetrafluoroethylene (PTFE) in the building applications
PTFE building membrane materials, such as the SOLUS series of products produced by TACONIC, has been widely used in large-scale public **** facilities: stadium roofing system, airport halls, exhibition centers, stations and so on. Lightweight It weighs a fraction of traditional building materials
High Strength Fiberglass is the strongest of textile fabrics, and it is even stronger than steel wire of the same diameter
Flexibility Unlike most solid building materials, the soft Solus product can be stretched into a variety of dynamic curved shapes
Translucency By transmitting light uniformly through the inner and outer surfaces. This creates a soft diffusion of light
Low Maintenance Minimal cleaning is required over the life of the fabric. Because the fabric surface is non-stick and taut, rain will wash away dirt
The surface is completely inert Harsh environments such as mold, acid rain, etc., will have no effect on the fabric surface
Weldability Each fabric frame will be welded together to form a one-piece canopy. The strength of the welds will be greater than the fabric itself
Long Service Life Over its lifetime, PTFE-coated glass fabrics show virtually no degradation. Currently, Solus fabrics are estimated to last at least 25 years
Fire resistance Solus fabrics have achieved a Class A fire evaluation, while it still maintains strong light transmission
2, polytetrafluoroethylene (PTFE) in the application of corrosion resistance
Because of the shortcomings of rubber, glass, metal alloys, and other materials in the corrosion resistance to meet the conditions of the harsh temperatures, pressures, and chemical media. Temperature, pressure and chemical media **** exist in the environment, the resulting loss is quite alarming. And PTFE material with its excellent corrosion resistance, has become the petroleum, chemical, textile and other industries, the main corrosion-resistant materials. Its specific applications include: delivery of corrosive gases, pipelines, exhaust pipes, steam pipes, high-pressure tubes in steel mills, aircraft hydraulic systems and cold pressure system of high and low pressure pipelines, distillation towers, heat exchangers, kettles, towers, tanks lining, valves and other chemical equipment. The performance of the seal is good or bad for the efficiency and performance of the whole machine and equipment have a great impact. PTFE material has a corrosion resistance, aging resistance, low coefficient of friction and non-adhesive, wide range of temperature resistance, elasticity and good characteristics make it very suitable for use in the manufacture of corrosion-resistant requirements of the use of higher than 100 ℃ temperature seals. Such as machines, heat exchangers, high-pressure containers, large-diameter containers, valves, pumps, grooved flange seals, glass reaction pots, flat flanges, large-diameter flange seals, shafts, piston rods, valve rods, worm gear pumps, tie rods, and other seals. 2, polytetrafluoroethylene (PTFE) low friction performance in the application of load As a result of the friction part of the equipment is not suitable for oil lubrication, such as lubricating grease will be solvent dissolved and failed occasions or paper, pharmaceutical, food, textile and other industrial areas of the product needs to avoid lubricant contamination, so that the filling of PTFE material to become the parts of the machinery and equipment oil-free lubrication (directly under load) of the most desirable materials. The material is the most ideal material for oil-free lubrication (direct load bearing) of machinery and equipment parts. This is due to the fact that the coefficient of friction of this material is the lowest of any known solid material. Its specific uses include chemical equipment, paper machinery, agricultural machinery bearings, used as piston rings, machine tool guides, guide rings; in civil engineering widely used as bridges, tunnels, steel roof, large chemical pipelines, storage tanks support slider, as well as used as bridge bearings and bridges and transitions.
3, polytetrafluoroethylene (PTFE) in electrical and electronic applications
PTFE material inherent low loss and small dielectric constant so that it can be made into enameled wire for micro-motors, thermocouples, control devices, etc.; PTFE film is the manufacture of capacitors, radio insulating liner, insulated cables, motors, and transformers ideal insulating materials, is also an indispensable material for industrial electronic components, aerospace, etc. One of the indispensable materials for industrial electronic components; the use of fluoroplastic film on the oxygen permeability, and the permeability of water vapor is small this selective permeability, can be manufactured oxygen sensors; the use of fluoroplastics at high temperatures and high pressures under the occurrence of polar charge deviation phenomenon of the characteristics of the manufacture of microphones, loudspeakers, robots on the parts, etc.; the use of its low refractive index characteristics, can be manufactured optical fiber.
4, polytetrafluoroethylene (PTFE) in the medical and pharmaceutical applications
Expanded PTFE material is pure inert, has a very strong biological adaptability, will not cause the body's rejection, no physiological side effects on the human body can be used by any method of disinfection and has a multi-porous structure, so that it can be used for a variety of rehabilitation solutions, including regeneration of soft tissues for the artificial vascular and patches for soft tissue regeneration, as well as surgical sutures for vascular, cardiac, general and orthopedic surgery.
5, polytetrafluoroethylene (PTFE) anti-adhesive performance of the application
PTFE material has the smallest surface tension in the solid material, does not adhere to any substance, but also has excellent resistance to high and low temperatures, which makes it in such as the manufacture of non-stick pots and pans of anti-adhesive applications is very broad. The anti-stick process consists of two main types: PTFE parts or sheets mounted on the substrate, and PTFE coating or glass composite with the paint cloth after heat shrinkage and set on the substrate. With the continuous development of materials application technology, PTFE material of the three major shortcomings: cold flow, difficult to weld, difficult to melt processing is gradually being overcome, thus making it in the optics, electronics, medicine, petrochemical oil transmission seepage prevention and other areas of application in the field of broader prospects.