At present, a lot of machinery or equipment can be used above the seals, including construction machinery, marine machinery, petroleum machinery, medical equipment, fitness equipment, agricultural machinery, automobiles, municipal engineering, heating pipes and water pipes and so on too much. And the requirements of the seals used in various industries are also different, some need to be oil-resistant, oxidation-resistant, heat-resistant, anti-wear and so on. There is also a variety of industries need seals of different materials, such as polyurethane, EPDM and so on.