What is Gum Rosin
Gum rosin is an organic compound of monoterpene, turpentine and resin acid. Also known as colophony or rosin, it is a solid form of pine oleoresin from pine trees (mostly conifers). It is produced by heating fresh liquid resin in order to vaporize the volatile liquid terpene components. It is semi-transparent and varies in color from pale yellow to amber. Rosin is brittle at room temperature, but melts at higher temperatures. It is insoluble in water and soluble in organic solvents. Gum Rosin also has a faint piny odour. It consists mostly of different resin acids, especially abietic acid. Gum Rosin can be found in Indonesia where it is derived from the distillation of Oleo Pine Resin. Different grades of gum rosin like WW, WG and X grade are available. Gum Rosin is also found in China where they are also produced from Oleo Pine Resin. The species of pine tree include P.massoniana, P.yunnanenisis and P.elliottii. These pine trees are located in the forested areas on provinces of Yuanan, Guangzhou, Fujian, Jiangxi and Sichuan and southern of China.
Gum Rosin is produced from the crude pine resin collected from pine trees. The resin is subjected to distillation and the distillation process is carried out in large copper stills. The volatile liquid terpene components would separate from the mixture as it vaporizes at a temperature between 100 to 160⁰C, leaving behind fluid rosin as the distillate. This fluid rosin is collected and purified by passing it through straining wadding. The condensate left behind is called turpentine oil.