As we all know, there are many products in the plastics industry whose names are replaced by abbreviations. For example, PVC, PP, PE, UHMWPE, HDPE, and so on are familiar to everyone. But when people search for PTFE, Teflon will appear at the same time. What is the difference between the two? Let’s find out.
What is PTFE?
PTFE stands for Poly tetra fluoroethylene, commonly known as “Plastic King”, is a high molecular polymer obtained by polymerizing tetrafluoroethylene as a monomer. White waxy, translucent, excellent heat and cold resistance, can be used for a long time at -180 ~ 260ºC. This material has acid and alkali resistance, resistance to 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 easy cleaning of the inner layer of water pipes.
What are the advantages of PTFE?
Insulation: Not affected by the environment and frequency, the volume resistance can reach 1018 ohm·cm, the dielectric loss is small, and the breakdown voltage is high.
High and low-temperature resistance: little change in temperature, wide temperature range, usable temperature -190~260℃.
Self-lubricating: It has the smallest friction coefficient among plastics and is an ideal oil-free lubricating material.
Surface non-stick: None of the known solid materials can adhere to the surface, and it is a solid material with the smallest surface energy.
Atmospheric aging resistance, radiation resistance, and low permeability: long-term exposure to the atmosphere, the surface, and properties remain unchanged.
Incombustibility: The oxygen limit index is below 90.
Chemical and weather resistance: PTFE is hardly corroded by any chemical agent except molten alkali metals. For example, when boiled in concentrated sulfuric acid, nitric acid, hydrochloric acid, or even in aqua regia, its weight and properties are unchanged, and it is almost insoluble in all solvents, only slightly soluble in peralkanes (about 0.1g/100g) above 300 °C. PTFE does not absorb moisture, is non-flammable, and is extremely stable to oxygen and ultraviolet rays, so it has excellent weather resistance.
Next, let’s take a look at the specific applications developed based on some of the advantages of PTFE.
What are the applications of PTFE?
Application of anti-corrosion performance
Due to the defects in corrosion resistance of materials such as rubber, glass, and metal alloys, it is difficult to meet the harsh environment of coexistence of temperature, pressure, and chemical medium, and the resulting losses are quite alarming. 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 aircraft hydraulic systems and cold-pressing systems, rectification towers, heat exchangers, kettles, towers, tanks linings, valves, and other chemical equipment.
The performance of the seal has a great influence on the efficiency and performance of the entire machine. The characteristics of corrosion resistance, aging resistance, low friction coefficient and non-stickiness, wide temperature resistance range, and good elasticity of PTFE material make it very suitable for the manufacture of seals with high corrosion resistance requirements and operating temperature higher than 100 °C. Such as machinery, heat exchangers, high-pressure vessels, large-diameter vessels, valves, seals of grooved flanges of pumps, glass reaction vessels, flat flanges, seals of large-diameter flanges, shafts, piston rods, valve rods, Turbine pumps, tie rod seals, etc.
Application of low friction performance in load
Because the friction part of some equipment should not be lubricated, for example, in the case where the lubricating grease will be dissolved by the solvent and fail, or the products in the papermaking, pharmaceutical, food, textile, and other industrial fields need to avoid the contamination of the lubricating oil, which makes the filled PTFE material become a The most ideal material for oil-free lubrication (direct load-bearing) of mechanical equipment parts. This is because the coefficient of friction of this material is the lowest of any known solid material. Its specific uses include bearings for chemical equipment, papermaking machinery, agricultural machinery, piston rings, machine tool guides, and guide rings; widely used in bridges, tunnels, steel structure roof trusses, large chemical pipes in civil engineering
It can be used as the support slider of the road and the storage tank, as well as the bridge support and the bridge swivel.
Application in electronic and electrical
The inherent low loss and low dielectric constant of PTFE materials make it possible to make enameled wires for use in micro motors, thermocouples, control devices, etc.; PTFE films are ideal for the manufacture of capacitors, radio insulating liners, insulating cables, motors and transformers Insulating materials are also one of the indispensable materials for industrial electronic components such as aerospace; oxygen sensors can be manufactured by using the selective permeability of fluoroplastic films with high permeability to oxygen and low permeability to water vapor; Microphones, speakers, parts on robots, etc. can be manufactured by utilizing the characteristics of fluoroplastics with polar charge deviation under high temperature and high pressure; optical fibers can be manufactured by utilizing their low refractive index characteristics.
Application in medical and pharmaceutical fields
Expanded PTFE material is pure inert, has very strong biological adaptability, does 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, which can be used in a variety of rehabilitation solutions, including artificial blood vessels and patches for soft tissue regeneration and surgical sutures for vascular, cardiac, general surgery and plastic surgery.
Application of anti-stick performance
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, which makes it widely used in anti-sticking such as making non-stick pans. The anti-sticking process mainly includes two kinds: installing PTFE parts or sheets on the substrate and wrapping the PTFE coating or the varnished cloth with glass on the substrate through heat shrinkage.
What are the disadvantages of PTFE?
In fact, PTFE is not without its shortcomings. Cold flow, difficult welding, and difficult melt processing have not been overcome.
It is hoped that with the continuous development of material application technology, the three major shortcomings of PTFE materials can be solved. Then it will have broader application prospects in various fields such as optics, electronics, medicine, petrochemical oil transportation, and anti-seepage.
What is Teflon?
In fact, Teflon is a registered trademark used by DuPont on its line of fluoropolymer products. Manufactured by Dr. Roy J. Plunkett in Jackson’s laboratory.
History of Teflon
About 70 years ago, chemist Dr. Roy J. Plunkett invented polytetrafluoroethylene resin in DuPont’s Jackson Laboratory in New Jersey, USA, and DuPont used “Teflon” as the brand name for the product. Subsequently, DuPont developed a series of products in addition to Teflon PTFE resin, including Teflon AF (amorphous fluoropolymer), Teflon FEP (fluorinated ethylene propylene resin), Teflon FFR (fluoropolymer foam resin), Teflon NXT fluoropolymer resin, Teflon PFA (perfluoroalkoxy resin) and so on.
Teflon and PTFE are the same product. But Teflon will be more expensive because manufacturers need to spend money to obtain a Teflon trademark license.
If you would like to know more about PTFE, please contact our plastics experts at email@example.com