Polytetrafluoroethylene ---- mechanical properties
The coefficient of friction of PTFE is extremely small, only 1/5 of that of polyethylene, which is an important characteristic of perfluorocarbon surfaces. And because of the fluorine-carbon chain intermolecular force is very low, so polytetrafluoroethylene has non-stick.
PTFE in -196 ~ 260 ℃ in a wide range of temperature are to maintain excellent mechanical properties, one of the characteristics of perfluorocarbon polymer is not brittle at low temperatures.
PTFE density is large, 2. 14 a 2. 20g/cm3, almost non-absorbent, equilibrium water absorption rate of less than 0. 01%.
PTFE is a typical soft and weak polymer, the mutual gravitational force between macromolecules is small, stiffness, hardness, strength are small, in the long-term role of stress will be deformed.
PTFE is a typical plastic with cold flow when loaded, and creep varies with compressive stress, temperature and crystallinity, the higher the temperature, the greater the creep. The crystallinity of PTFE is between 55% and 80%, creep does not exceed 2%; when the crystallinity is below 55% and above 80%, creep increases rapidly.
The excellent mechanical properties of PTFE is a small friction factor, between 0. 01 and 0. 10, the smallest among existing plastic materials, and even all engineering materials.
PTFE friction factor increases with the increase in sliding rate, when the linear velocity reaches 0. 5 a. 1. 0m / s or more tends to stabilize; and static friction factor is less than the dynamic friction factor, this characteristic will be used in bearing manufacturing, can reduce its starting resistance, so that it is very smooth from the start to operation. PTFE friction factor decreases with the increase in load, when the load reaches 0. 8 MPa or more tends to Constant. At high speed and high load, the friction factor of PTFE is less than 0.01. From ultra-low temperature to the melting point of PTFE, the friction factor is almost constant, and only when the surface temperature is higher than the melting point, the friction factor increases sharply.
Due to the low intermolecular gravitational force, the hardness of PTFE is low and easily worn by other materials. However, as long as the surface roughness of the abrasive material is suitable, the amount of wear of PTFE can be reduced to a considerable extent.
1. FEP can also be made into heat shrinkable tubes, which can be used for coating transfer rollers in printing presses. 2.High surface quality can prevent print adhesion, contamination and discoloration. 3. In the medical industry, FEP tubes are mainly used as catheters or in the field of endoscopy. 4. It also prevents contamination of the delivered liquid during the injection process. 5. Therefore, the biocompatibility of FEP for medical use is also excellent. 6. FEP can be sterilized by all conventional methods.
Heat exchangers are used in a wide range of applications in industries such as air conditioning, power plants, oil refineries and internal combustion engines. You may not know that you are familiar with heat exchangers. Take for example the radiator in your car. Heat exchangers keep your equipment cool and prevent overheating and malfunction. You may have seen someone open the hood of their car on the side of the road and smoke comes out as a result of a radiator failure.
PTFE material has the smallest surface tension and inertness among solid materials and does not adhere to any substance. PTFE material has the lowest coefficient of friction, excellent self-lubrication, and also has excellent resistance to high and low temperatures, which makes it very widely used in applications such as the manufacture of non-stick pan anti-stick. PTFE is also used in rollers and other parts, as a guide, and as a material for the production of non-stick pans.
1. PTFE white curly staple fiber is generally manufactured using the membrane splitting method, fiber strength is greater than the brown fiber produced by the emulsion spouting method, fiber can also be used to add color technology as needed to make a variety of colored fibers. It is suitable for high temperature environment, excellent chemical stability, low shrinkage rate, anti-aging and other characteristics.
Polytetrafluoroethylene (F4, PTFE) has a series of excellent performance: high temperature resistance - long-term use temperature 200 ~ 260 degrees, low temperature resistance - still soft at -100 degrees; corrosion resistance - can resist aqua regia and all organic solvents; weather resistance - The best aging life in plastic; high lubrication - with the smallest coefficient of friction in plastic (0.04); non-stick - with the smallest surface tension in solid materials without adhesion to any material; non-toxic - with physiological inertia; excellent electrical properties, is the ideal C-class insulation material.
The coefficient of friction of PTFE is extremely small, only 1/5 of that of polyethylene, which is an important characteristic of perfluorocarbon surfaces. Due to the extremely low intermolecular forces between fluorine-carbon chains, PTFE has non-stick properties.