Due to the many advantages and excellent properties of PTFE, rubber has been gradually replaced in reciprocating sealing applications. The reciprocating PTFE seals that are currently available are:

(1) The V-shaped packing seal replaces the original rubber cloth structure, which improves the performance.

(2) Bowl-shaped seal, mainly used on filling machines.

(3) Seal with inner spring, It has a low coefficient of friction and does not cause creep and stick-slip in the cylinder. Since one end of the opening faces the high pressure end, the high pressure fluid is filled into the cavity, so that the sealing pressure becomes tighter and tighter, and no manual adjustment is required. The spring force is guaranteed to be close to the cylinder wall during installation or during vacuum suction. This type of sealing pressure is very high, up to 400MPa, wide operating temperature (-200 ° C ~ +260 ° C), can be used normally in dry friction and oil-free occasions, allowing high pressure operation. It can be used for oiling, as well as water and various chemical fluids or gases.

PTFE seals have been developed for decades and are now more and more perfect. However, it has high production cost, complicated process and lack of high elasticity, and cannot completely replace cheap rubber seals. In particular, when sealing a type of fluid such as water, it has a large amount of wear and a long life, and cannot completely replace the mechanical seal. In order to make the PTFE seal more perfect, engineers from all over the world are constantly studying its wear mechanism, looking for different filling formulas, improving the filling materials, and improving the surface material of the shaft. I believe that a new generation of PTFE seal will appear in the future. Meet the increasingly demanding requirements of modern machines.