PTFE media usually refers to a media made of polytetrafluoroethylene (PTFE for short). The following is a detailed introduction to PTFE media:
Ⅰ. Material properties
1.Chemical stability
PTFE is a very stable material. It has strong chemical resistance and is inert to almost all chemicals. For example, in the environment of strong acids (such as sulfuric acid, nitric acid, etc.), strong bases (such as sodium hydroxide, etc.) and many organic solvents (such as benzene, toluene, etc.), PTFE materials will not react chemically. This makes it very popular in applications such as seals and pipe linings in the chemical and pharmaceutical industries, because these industries often need to deal with a variety of complex chemicals.
2.Temperature resistance
PTFE media can maintain its performance over a wide temperature range. It can work normally in the temperature range of -200℃ to 260℃. At low temperatures, it will not become brittle; at high temperatures, it will not decompose or deform as easily as some ordinary plastics. This good temperature resistance makes PTFE media have important uses in aerospace, electronics and other fields. For example, in the hydraulic system of an aircraft, PTFE media can withstand the high temperature generated by ambient temperature changes and system operation during flight.
3.Low friction coefficient
PTFE has an extremely low friction coefficient, one of the lowest among known solid materials. Its dynamic and static friction coefficients are both very small, about 0.04. This makes PTFE dielectric very effective when used as a lubricant in mechanical parts. For example, in some mechanical transmission devices, bearings or bushings made of PTFE can reduce friction between mechanical parts, reduce energy consumption, and extend the service life of the equipment.
4.Electrical insulation
PTFE has good electrical insulation properties. It maintains high insulation resistance over a wide frequency range. In electronic equipment, PTFE dielectric can be used to make insulating materials, such as the insulation layer of wires and cables. It can prevent current leakage, ensure the normal operation of electronic equipment, and resist external electromagnetic interference.
For example, in high-speed communication cables, the PTFE insulation layer can ensure the stability and accuracy of signal transmission.
5.Non-stickiness
The surface of PTFE dielectric has a strong non-stickiness. This is because the electronegativity of fluorine atoms in the PTFE molecular structure is very high, making it difficult for the PTFE surface to chemically bond with other substances. This non-stickiness makes PTFE widely used in coatings for cooking utensils (such as non-stick pans). When food is cooked in a non-stick pan, it will not easily adhere to the pan wall, making it easier to clean and reducing the amount of grease used during cooking.
What is the difference between PVDF and PTFE?
PVDF (polyvinylidene fluoride) and PTFE (polytetrafluoroethylene) are both fluorinated polymers with many similar properties, but they also have some significant differences in chemical structure, performance and application. The following are their main differences:
Ⅰ. Chemical structure
PVDF:
The chemical structure is CH2−CF2n, which is a semi-crystalline polymer.
The molecular chain contains alternating methylene (-CH2-) and trifluoromethyl (-CF2-) units.
PTFE:
The chemical structure is CF2−CF2n, which is a perfluoropolymer.
The molecular chain is composed entirely of fluorine atoms and carbon atoms, without hydrogen atoms.
Ⅱ. Performance comparison
| Performance Index | PVDF | PTFE |
| Chemical resistance | Good chemical resistance, but not as good as PTFE. Good resistance to most acids, bases and organic solvents, but poor resistance to strong bases at high temperatures. | Inert to almost all chemicals, extremely chemically resistant. |
| Temperature resistance | The operating temperature range is -40℃～150℃, and the performance will decrease at high temperatures. | The operating temperature range is -200℃～260℃, and the temperature resistance is excellent. |
| Mechanical strength | The mechanical strength is high, with good tensile strength and impact resistance. | The mechanical strength is relatively low, but it has good flexibility and fatigue resistance. |
| Friction coefficient | The friction coefficient is low, but higher than PTFE. | The friction coefficient is extremely low, one of the lowest among known solid materials. |
| Electrical insulation | The electrical insulation performance is good, but not as good as PTFE. | The electrical insulation performance is excellent, suitable for high frequency and high voltage environments. |
| Non-stickiness | The non-stickiness is good, but not as good as PTFE. | It has extremely strong non-stickiness and is the main material for non-stick pan coatings. |
| Processability | It is easy to process and can be formed by conventional methods such as injection molding and extrusion. | It is difficult to process and usually requires special processing techniques such as sintering. |
| Density | The density is about 1.75 g/cm³, which is relatively light. | The density is about 2.15 g/cm³, which is relatively heavy. |
Ⅲ. Application fields
| Applications | PVDF | PTFE |
| Chemical industry | Used to manufacture corrosion-resistant pipes, valves, pumps and other equipment, especially suitable for handling acidic or alkaline environments. | Widely used in linings, seals, pipes, etc. of chemical equipment, suitable for extreme chemical environments. |
| Electronic industry | Used to manufacture housings, insulation layers, etc. of electronic components, suitable for medium frequency and voltage environments. | Used to manufacture insulating parts of high-frequency cables and electronic connectors, suitable for high frequency and high voltage environments. |
| Mechanical industry | Used to manufacture mechanical parts, bearings, seals, etc., suitable for medium load and temperature environments. | Used to manufacture low-friction parts, seals, etc., suitable for high temperature and low friction environments. |
| Food and pharmaceutical industry | Used to manufacture parts of food processing equipment, linings of pharmaceutical equipment, etc., suitable for medium temperature and chemical environments. | Used to manufacture non-stick pan coatings, food conveyor belts, linings of pharmaceutical equipment, etc., suitable for high temperature and strong chemical environments. |
| Construction industry | Used to manufacture building exterior wall materials, roofing materials, etc., with good weather resistance and aesthetics. | Used to manufacture building sealing materials, waterproof materials, etc., suitable for extreme environments. |
Ⅳ. Cost
PVDF: Relatively low cost, more affordable.
PTFE: Due to its special processing technology and excellent performance, the cost is higher.
Ⅴ. Environmental impact
PVDF: A small amount of harmful gases may be released at high temperatures, but the overall environmental impact is small.
PTFE: Harmful substances such as perfluorooctanoic acid (PFOA) may be released at high temperatures, but modern production processes have greatly reduced this risk.
Post time: May-09-2025