Single Cartridge Seals,Single-End Face Containerized Seal,Single Cartridge Mechanical Seal,Chesterton Cartridge Mechanical Seal Shanghai Enactus Industrial Co., Ltd. , https://www.enactuseal.com
Application of low friction performance of PTFE gasket
PTFE gaskets are not recommended for lubrication due to the potential issues caused by friction in certain equipment. For instance, if lubricants are dissolved by solvents, or in industries like paper, pharmaceuticals, food, and textiles, where contamination from lubricants must be avoided, PTFE becomes the ideal material for mechanical components that require oil-free operation under direct load. This is because PTFE has the lowest coefficient of friction among all solid materials, making it highly suitable for applications where lubrication is either impractical or undesirable.
PTFE gaskets possess excellent comprehensive properties, including high-temperature resistance, corrosion resistance, non-stick characteristics, self-lubrication, outstanding dielectric properties, and a low friction coefficient. By adding fillers that can withstand the sintering temperature of PTFE, its mechanical properties can be significantly enhanced while maintaining its other superior characteristics. Common fillers include glass fiber, metals, metal oxides, graphite, molybdenum disulfide, carbon fiber, polyimide, and EKONOL. These fillers can increase wear resistance and the PV limit value by up to 1,000 times.
The depolymerization of polytetrafluoroethylene (PTFE) into tetrafluoroethylene requires only 171.38 kJ per mole, which means that during pyrolysis, PTFE mainly breaks down into tetrafluoroethylene. At temperatures of 260°C, 370°C, and 420°C, the weight loss rate of Teflon gaskets is 1×10â»â´, 4×10â»Â³, and 9×10â»Â², respectively. This indicates that PTFE can be used for long-term applications at 260°C. However, care must be taken due to toxic by-products such as fluorophosgene and perfluoroisobutylene, and PTFE should be kept away from open flames.
PTFE gaskets are widely used in various applications, including bearings in chemical equipment, papermaking machinery, agricultural machines, piston rings, machine tool guides, and guide rings. They are also commonly found in civil engineering projects such as bridges, tunnels, steel trusses, and large-scale structures. Additionally, they are used in chemical pipelines, support slides for storage tanks, and as bridge supports and swivels.
PTFE gaskets exhibit excellent chemical resistance and are often used as stuffing box gaskets, pipe thread sealing materials, packing, microporous diaphragms, filter plates, lining devices, membranes, liquid level floaters, and experimental instruments. They are also used in communication satellites, coaxial transmission lines, ultra-high-frequency communication systems, micro-motor windings, control cables in thermal power plants, and insulation for double water-cooled pipes and electrolysis cells.
Due to its low friction coefficient, PTFE is non-sticky and ideal for use in environments where adhesion is a concern. To enhance wear resistance and creep resistance, filled PTFE is commonly used in manufacturing mechanical parts such as sealed bearings, piston rings, rollers, and intake heads.
PTFE gaskets have a low dielectric constant and dielectric loss over a wide frequency range, along with high breakdown voltage, volume resistivity, and arc resistance. The production of PTFE involves radical polymerization of tetrafluoroethylene. Industrial polymerization typically occurs under agitation in the presence of water, which helps dissipate heat and control temperature. The process is usually carried out between 40°C and 80°C under pressures ranging from 3 to 26 kgf/cm², with initiators such as inorganic persulfates or organic peroxides, or even redox initiation systems, being used.
Aramid packing is another type of sealing material used in fluid-handling equipment such as pumps, valves, pipes, and containers. It is suitable for sealing granular fluids, steam, organic solutions, acids, and alkalis. Aramid packing offers excellent lubricity, wear resistance, high strength, good chemical resistance, high rebound, low cold flow, and easy disassembly. It is especially effective for dynamic seals involving media containing solid particles.
Technical parameters for aramid packing include a temperature range of -100°C to +300°C, pressure up to 35MPa, and a pH range of 2 to 13.
Pure PTFE packing, also known as oil-containing PTFE packing, is specially treated with low-friction PTFE wire and is suitable for dynamic sealing in pumps. However, it is generally not recommended for use in high-speed pumps. Standard specifications for oil-containing PTFE packing range from 3×3mm to 50×50mm, with custom sizes available upon request. Technical parameters include a pressure rating of 10MPa, a temperature range of 260°C, a pH range of 0–14, and a linear speed of 10m/s.
Expanded graphite packing is made from flexible graphite wire and offers excellent self-lubrication, thermal conductivity, a low friction coefficient, versatility, flexibility, and high strength. It can be reinforced with carbon fiber or glass fiber depending on the application. This type of packing provides good protection for the shaft and is widely used in various industrial settings.
Http://news.chinawj.com.cn Editor: (Hardware Business Network Information Center) http://news.chinawj.com.cn