Natural rubber can be divided into solid natural rubber (film and particle rubber) and concentrated latex according to its morphology. According to the different production process and appearance, it can be divided into cigarette glue, air-dried film, white wrinkled film, brown wrinkled film and so on. Natural rubber is a natural polymer compound with polyisoprene as the main component, and its molecular formula is (C5H8)n, in which 9 1%~94% is rubber hydrocarbon (polyisoprene), and the rest is non-rubber substances such as protein, fatty acids, ash and sugar. Natural rubber is the most widely used universal rubber.