Natural rubber is an important strategic material for national economy and people's livelihood, widely used in transportation industry, medical and health industry, industry, agriculture, construction industry, defense industry and people's daily life. About 70% of the world's natural rubber is used for tire manufacturing in the transportation industry, of which about 80% use No. 20 rubber; the use of No. 20 rubber has become the main symbol of a country's tire industry technology and process level.

Rubber is mainly divided into natural rubber and synthetic rubber. Natural rubber is the collection of natural latex from the Brazilian rubber tree, after coagulation, drying and other processing procedures and made of elastic solid. Synthetic rubber is a synthetic highly elastic polymer, also known as synthetic elastomers, broadly speaking, refers to chemical methods of synthetic manufacturing of rubber, in order to distinguish from the natural rubber produced from the rubber tree. Natural rubber can be divided into two categories according to its form: solid natural rubber (film and standard rubber) and concentrated latex (called "natural latex" under the Customs Tariff Code). Solid natural rubber has a traditional system and the standard system: the traditional system to produce film (smoke film, etc.), the standard system to produce standard rubber. Standard rubber, that is, technically graded rubber (Technically Specified Rubber, TSR for short), is graded according to impurities, ash, nitrogen content, volatile matter, plasticity value, plasticity retention rate and color index and other physicochemical performance indicators, of which the impurity content is the dominant indicator. According to the national standards and ISO standards, the standard rubber is mainly divided into the following categories according to different raw materials and properties: LoV (Low Viscosity Constant Viscose), CV (Constant Viscose), L (Light-colored Rubber), WF (Whole Field Latex), CV (Constant Viscose), L (Light-colored Rubber) and WF (Whole Field Latex). L (Light-colored Rubber), WF (Whole Field Latex Rubber), No. 5, No. 10, No. 20, No. 10 Constant Viscose (10CV) and No. 20 Constant Viscose (20CV).