Sealing is a component or measure that prevents fluid or solid particles from leaking between adjacent joint surfaces and prevents external impurities (such as dust and moisture, etc.) from intruding into the interior of machinery and equipment. Technology is the continuous change of production tools, equipment, equipment, languages, digital data, information records, etc., from low to high levels in the continuous development of social productivity, which is called technology. Sealing technology is in the continuous development of social productivity, in order to prevent fluid or solid particles from leaking from adjacent bonding surfaces, and to prevent external impurities (such as dust and moisture, etc.) from intruding into machinery and equipment, the level of components or measures is continuously improved . Sealing technology has now become a special research field, and its importance in practical applications has become more and more obvious after years of development.

Sealing technology has now become a specialized research field. After years of development, its importance in practical applications has become more and more obvious. As early as the 15th century, "seals" were made of elastic materials for water pumps at that time. This "seal" was used until the Archimedes era around 1700. A leather gasket was added. Now this kind of leather seal is very rare, only used in some special occasions.

The industrial use of elastic materials to make seals began in the early 19th century. In 1856, a circular ring made of elastic material was used in a steam engine. A similar sealing technology was included in a French patent in 1886, and a fluid pump was also used. The further research, development and application of this type of circular ring was completed by the Danish inventor and continuing manufacturer Niels A Christensen. He designed a hydraulic cylinder and a matching sealing system. The technology was published in 1930 Announced, the ring-shaped seal applied for in 1933 won the grand prize in 1938. But in practical applications, this circular ring (ie O-ring) quickly showed its limitations in dynamic sealing, which caused a cross-sectional shape and was turned into a groove to prevent it from moving The research and development of seals.