Gum rosin is a native product in China. Different from floating rosin which is made from the papermaking pulp that is largely produced in the western world, gum rosin from China is distilled from oleoresin, a natural pine excrete. It has been used in many fields in which other kinds can not substitute. Amongst the 400,000-500,000Mt/year trading quantity of rosin in the world, the Chinese gum rosin accounts to about 60-70%.
Rosin is a naturally occurring resin derived from pine trees and is classified into three types:
- Wood rosin
- Gum rosin
- Tall oil rosin
Terpenes are a class of organic chemicals naturally found in plant life, of which pine and citrus sources are the most commercially important.
Wood rosin is a type of materials produced from unique manufacturing process includes new custom-designed stump grinding equipment, special wood extraction techniques, and carefully controlled refining.
Gum rosin comes from the crude pine gum exudates of “tapped” living pine trees.
Crude sulfate turpentine is a byproduct of pulping of pine wood for paper, and d-limonene, a side stream of the processing of citrus fruit for juice concentrate. Gum turpentine is a terpene stream from the same source as gum rosin.
Chinese Gum Rosin Production
The total production of rosin (including gum rosin, wood rosin and tall oil rosin) in the world is 1,050,000 MT/year. These rosin include:
1) Wood rosin and tall oil rosin 435,000 MT/year, made in America and Europe
2) Gum Rosin 615,000 MT/year, including
- China 400,000-450,000 MT/year
- Indonesia 53,000 MT/year
- Brazil 40,000 MT/year
- Mexico 27,000 MT/year
- India 26.6 MT/year
- Russia 18,000 MT/year
- Portugal 15,000 MT/year
- Other countries
The above figure shows that the gum rosin from China accounts about 70% of the total production of gum rosin in the world.
Chemical Component Comparison
Chinese pines provide an oleoresin that is high in alpha-pinene and low in beta-pinene. The sesquiterpene content is relatively very high and its constitution is various. The content of langifolene can reach to 2.5-6.4%. The diterpene content in the oleoresin is below 60%. The difference in chemical components means different utilities of pine resources in the world.
Gum rosin is produced from tapping collected resin. 1,000kg of oleoresin can be distilled to yield around 770-800kg of gum rosin and around 120kg of gum turpentine.
The comparison of the chemistry of Chinese pine and European and American pine is shown in below table.
Table 3-3. Distinction between chemical characteristics of oleoresins from pines in China, USA and Europe (in % of total terpenes).