PTFE Properties
1. Insulation
PTFE is 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.
2. High and Low Temperature Resistance
The influence on the temperature change is not much to PTFE. The working temperature is significant, ranging from -190 to +260 °C.
3. Self-lubricating
PTFE has the lowest friction coefficient in plastic and is an ideal oil-free lubricating material.
4. Non-sticking Surface
None of solid materials known can adhere to PTFE's surface. It is a solid material with the smallest surface energy.
5. Resistance to Atmospheric Aging, Radiation And Low Permeability
Long-term exposure to the atmosphere, surface and performance remain unchanged.
6. Non-combustibility
The oxygen limit index is below 90.
7. Chemical and Weather Resistance
In addition to molten alkali metal, PTFE is hardly corroded by any chemical agents. For example, in concentrated sulfuric acid, nitric acid, hydrochloric acid, or even boiling in aqua regia, there is no change in weight and properties, and it is almost insoluble in all solvents, and is slightly soluble in per-alkanes (about 0.1 g/100 g) only above +300 °C.
8. PTFE does not absorb moisture, and is non-combustible and extremely stable to oxygen and ultraviolet rays, and has excellent weather resistance.
PTFE Properties
Physical Characteristics | Unit | Value |
Density | g/cm3 | 2.14-2.22 |
Water Absorption Rate（24h） | % | ＜0.05 |
Ultimate Oxygen | % | >95 |
Tensile Strength | Mpa | 21.1-28.0 |
Heat of Combustion | MG/kg | 4.9-5.0 |
Elongation（25℃） | % | 200-400 |
Bending Strength | Mpa | 11-14 |
Compressive Strength | Mpa | 7 |
Impact Strength | KJ/㎡ | 100 |
Hardness | Shore Hardness | D50-D65 |
Dynamic & Static Friction Coefficient | / | 0.04 |
Crystal Melting Point | ℃ | 327 |
Heat Distortion Temperature | ℃ | 120 |
Glass Transition Temperature | ℃ | -120 |
Operating Temperature | ℃ | -180 ~ +250 |
Decomposition Temperature | ℃ | ＞415 |
Thermal Conductivity Coefficient | W/km | 0.24 |
Linear Expansion Coefficient | 1/℃ | 1.09*104～2.165*104 |
DC Breakdown Voltage | KV/mm | ＞60 |
Dielectric Constant 106 Weeks | / | 1.8-2.2 |
Dielectric Loss Tangent 106 Weeks | / | ＜2.5*104 |
Resistivity | Ω .m | >106 |
Arc Resistance | sec | ＜160 |
Enhanced PTFE performance
Polytetrafluoroethylene (PTFE) has excellent heat resistance, chemical resistance, non-adhesiveness and weather resistance, but it has a large linear expansion coefficient, poor dimensional stability, low hardness, and poor wear resistance. Under the load, PTFE shows a large "cold flow", which limits its application. In order to overcome the shortcomings to meet different application requirements, PTFE can be modified by adding an appropriate amount of filler to achieve excellent wear resistance, high temperature resistance, high strength, high stiffness and dimensional stability while maintaining low friction characteristics. Fillers include glass fiber, para-polyphenylene. , molybdenum disulfide, polyphenylester, graphite, carbon powder, carbon fiber, bronze powder, silicon powder, etc..
Reinforcement of PTFE by Filling Modified Materials
Filler | Improved Performance |
Glass Fiber | Improve compressive strength, stiffness, wear resistance, reduce cold flow, and resist organic solvents. |
Carbon | Improve tensile strength, hardness, wear resistance, high temperature resistance, and thermal conductivity. |
Carbon Fiber | Improve compression creep resistance, cold flow resistance, high temperature resistance, and thermal conductivity. |
Graphite | Improve lubricity and thermal conductivity, and reduce friction coefficient. |
Bronze | Improve tensile strength, hardness, wear resistance, thermal conductivity, and reduce cold flow. |
Polyphenylester | Improve creep resistance, dimensional stability, and high temperature resistance. |
Stainless Steel | Increase heat transfer coefficient, reduce cold flow, and resist chemical corrosion. |
Glass Emblem | Improve compression and flexibility under low stress. |
Diatomaceous Earth | Improve compression creep resistance, improves porosity and flexibility. |
