Natural rubber can be divided into two categories by form: solid natural rubber (film and granular rubber) and concentrated latex. In daily use, solid natural rubber accounts for the majority of the proportion.

Film according to the different manufacturing process and shape, can be divided into cigarette gum, air-dried film, white wrinkle, brown wrinkle, etc. Cigarette gum is a representative variety of natural rubber, has been a large amount of, widely used rubber, cigarette gum is generally classified according to the shape, divided into special JI, level -, level 2, level 3, level 4, level 5, a total of six, not up to level 5 is listed as the outer rubber.

The physical and chemical properties of the sealing ring manufacturers include impurity content, plastic initial value, plastic retention rate, nitrogen content, volatile content, ash content and color index seven items, among which the impurity content is the dominant indicator, According to the amount of impurities into 5L, 5, 10, 20 and 50 grades.

China's futures trading market Shanghai Futures Exchange natural rubber contract delivery grade for domestic - level standard glue SCR5 and imported cigarette gum RSS3, which domestic - level standard glue SCR5 is usually known as no. 5 standard glue, the implementation of the national technical supervision bureau issued the implementation of natural rubber GB/T8081 ~ 1999 version of the quality indicators. RSS3 of imported tobacco flake rubber is implemented in accordance with the "international standard for quality and packaging of natural rubber grade" (Green Book)(1979 edition).