In vacuum sealing, it is common to use a Teflon material as the sealing ring, which is mainly determined by its physical and chemical properties. Polytetrafluoroethylene is a polymer of tetrafluoroethylene. Polytetrafluoroethylene has a low dielectric constant and dielectric loss over a wide frequency range, and has high breakdown voltage, volume resistivity, and arc resistance.

Polytetrafluoroethylene can be formed by compression or extrusion; it can also be made into an aqueous dispersion for coating, impregnation or fiber making. PTFE is widely used in high-temperature, corrosion-resistant materials, insulating materials, anti-stick coatings, etc. in the atomic energy, aerospace, electronics, electrical, chemical, machinery, instrumentation, instrumentation, construction, textile, food and other industries. It can withstand the action of all strong acids, strong oxidants, reducing agents and various organic solvents other than molten alkali metal, fluorinated medium and sodium hydroxide above 300 °C.

PTFE sealing ring PTFE composite material is a new type of composite material which is composed of two or more different properties or different phase materials of PTFE blended, copolymerized or combined to have better performance than its constituent materials. Through material compounding, it not only exerts the excellent characteristics of PTFE, but also overcomes the shortcomings of cold flow creep and non-wear resistance of PTFE, so that it has antifriction, wear resistance, self-lubrication, corrosion resistance, heat resistance, aging resistance and resistance. Compression, creep resistance, dimensional stability and low coefficient of linear expansion, and improved thermal conductivity and hardness, reducing costs. This new type of composite material has been used at home and abroad to make seals for special working conditions, such as high pressure, high temperature, high speed, high vacuum, flammable and explosive, toxic, highly corrosive medium, etc. These seals are widely used in petrochemical industry. In the chemical fertilizer, aerospace, aerospace and nuclear industries, it is often used as a seal for reciprocating axial movement, such as the sealing of pistons and piston rods. It can be used for dry friction and oil-free lubrication, and oil lubrication can be carried out when conditions permit.

In order to enhance the elasticity of the PTFE composite seal, it must be combined with an elastomer, a compression ring, a convex seat, a concave seat, and various forms of metal springs to form an elastically actuated seal. The most common is metal spring actuation, which is to place a spiral flat spring or round wire spring in an annular space made by machining or molding in a sealing ring to ensure a high degree of elasticity and wear of the seal. Automatic compensation to create an excellent dynamic seal.