Natural rubber can be divided into standard glue (also known as granule glue), smoke film, concentrated glue, chalk film, light-colored film, glued rubber and air-dried film. The most commonly used are standard glue and smoke film. The standard glue is divided into four grades: one grade (SCR5), two grades (SCR10), three grades (SCR20), and four grades (SCR50). The smoked rubber is divided into five grades of No. 1-5 smoke film (RSS1-RSS5).

Standard glue: Standard rubber is mainly divided into No. 5 glue, No. 10 glue and No. 20 glue. No. 5 glue is a first-grade glue, which is the best glue, which contains 0.05% of impurities; No. 10 glue is a second-grade glue, which contains 0.10% of impurities, and No. 20 glue is a third-grade glue, which contains impurities. It is 0.20%. Different types of glue are used differently: No. 5 glue is generally used to make tire inner tube; No. 10 glue and No. 20 glue are generally used to make tire tires.

Tobacco film: A film obtained by fumigation of natural film that has been dehydrated by the smoke and heat generated by burning the coconut shell. The purpose of smoking is to dry the film and inject it with oxidized and preserved cresols. Tobacco film is a natural rubber of primary shape.

Concentrated rubber: can be used as a bonding material.

film:
Special grade white chalk film
The delivered product must be a very white, uniform, dry, firm rubber.
Discoloration, acid odor, dust, debris, grit or other foreign matter, oil or other smudges, signs of oxidation or overheating caused by any cause are not allowed.
First thin white crepe film
The delivered product must be white, dry, solid rubber. Allow for a slight difference in shades of color.
Special grade light-colored enamel film
The delivered product must be a very light, uniform, dry, firm rubber.
First-grade thin light-colored enamel film
The delivered product must be a light, dry, solid rubber. Allow for a slight difference in shades of color.
Secondary thin light tantalum film
The delivered product must be dry, solid rubber. The color is slightly darker than the first thin light-colored enamel film. Allow for slight differences in shades of color.
Rubber with stains and streaks is allowed to the extent indicated by the sample. However, in the tested plastic bags, the number of such plastic bags shall not exceed 10% of the number of tested plastic bags.
Except as permitted above, discoloration, dust, debris, grit or other foreign matter, oil or other smudges, signs of oxidation or overheating caused by any cause are not permitted.
Three-level thin light-colored enamel film
The delivered product must be a light yellow, dry, solid rubber. Allow for differences in shades of color.