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Gum rosins are probably the oldest raw materials for the chemical industry. The Assyrians and Babylonians used them to fix arrowheads and for cosmetic purposes, and collected the resin from the rosins of pine trees. Once the bark is removed, the tree closes the wound with a mixture of rosin and turpentine. Once collected, the turpentine is removed with steam distillation [1, 2]. About two kilograms of rosin can be collected per tree per year. - Y4 \8 ]# h) R1 X" s# L$ B0 c
The production of gum rosin is still made with the same intensive procedure which makes this uneconomic in regions with high labour costs. 9 a: n9 H1 a& U7 E2 L) h
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