Over the 20th century, the sealing material is asbestos in the field eliminated from coming to centuries. At first, people think asbestos seals have excellent heat resistance, corrosion resistance and other properties, which are widely used. Later found asbestos dust from the respiratory tract and pores into the body, harmful to human health. To this end, efforts to seek sealing material "non-asbestos." Among the many non-asbestos sealing material, good overall performance, low price comes graphite.

Graphite instead of potential asbestos after the 1980s, China's graphite sealing industry has been rapid development. At present, China's annual production of graphite seals 1000-2000 tons in between. All seals to replace asbestos, as well as 8000-9000 tons gap. Moreover, the current plant is very unevenly distributed, mostly concentrated in Zhejiang, Jiangsu, Shandong area, the majority of provinces is blank. Meanwhile, foreign to our country buy graphite rapidly growing number of seals, manufacturers often too late to supply. Graphite seal product type graphite sealing products are mainly divided into two categories: soft seal and hard seal. Soft seals, also called flexible graphite seals, graphite is chemically treated, heat expansion was "graphite worms" and then further processed into seals. The main varieties are: expanded graphite braided packing, flexible graphite and metal spiral wound gasket, reinforced flexible graphite gaskets, flexible graphite packing stereotypes. Hard seals porous graphite impregnated with resin or metal, and then processed into rotary seal or mechanical seal ring and stationary ring.

In addition, the combination of graphite and organic polymer compound, can be made of special seals. For example, combined with the polyurethane elastomer can be used for oil pumping seals; combined with PTFE can be used for the new upper and lower plunger valve seals. China's development of graphite sealing industry has resources and technological advantages of both the world's rich reserves of graphite graphite storage resources is extremely uneven, many countries have nothing, and our reserves are particularly rich.

China currently only in Hebei, Inner Mongolia, Shandong, Henan, Heilongjiang, Jilin, Hubei and other places mining, production has ranked first in the world. There Xinjiang, Sichuan, Jiangxi, Hunan, Yunnan, Tibet, Fujian and other places did not move mine closure. Therefore, we can make full use of graphite resources, vigorously develop the graphite sealing industry. Our country in some respects (eg PTFE seals) less advanced people, and graphite seals production technology is not backward. Recognized worldwide, "expanded graphite braided packing" is China's first; China's production of graphite sheet, is the world's widest, reaching 1.5 m; developed in China with a computer flexible graphite wrapping machine, but also in the world advanced level. Of course, no denying that China's current production of graphite seals still uneven in quality, which is mainly management problem, not a technical level reach.