At present, synthetic rubber is the main sealing material required for oil seal manufacturing. Because the selection and structural design of sealing material are the main factors affecting the performance and service life of oil seal, it is very important to correctly master the performance of rubber to properly select the rubber sealing material used. What kind of rubber to choose as the most appropriate oil seal material? This should be determined according to the associated parameters of the oil seal, that is: the radial force on the shaft should be high enough to prevent the leakage of the oil seal, low enough to maintain a certain oil film thickness to maintain low friction heat; The oil seal should have enough interference to overcome the influence of eccentricity in use; The area of the lip in the contact area is also a determining factor. The oil seal material directly affects the above three parameters, because the material changes with time and temperature, and the key parameters also change, such as: with the increase of temperature, the modulus of the material decreases, so that the radial force of the oil seal material changes. Radial force and interference amount are affected by thermal expansion, material swelling caused by sealing medium and hardness of rubber material.

Based on the above reasons, the following characteristics should be considered in the selection of oil seal materials: oil seal sealing material and sealing medium compatible, oil seal sealing material does not occur swelling, hardening and other phenomena due to sealing medium; Oil seal sealing material has good heat resistance and wear resistance; The oil seal material has moderate elasticity and ADAPTS to changes in shaft roughness and eccentricity.

As the formula of rubber sealing materials changes a lot, new sealing materials continue to appear, the existing sealing materials are constantly improved. At present, the most commonly used manufacturing oil seal is mainly nitrile rubber, polypropionate rubber, silicone rubber, fluorine rubber and ptfe.