ROSIN -16 KG PACK

Description

Rosin, also called colophony or Greek pitch (Latin), is a solid form of resin obtained from pines and some other plants, mostly conifers, produced by heating fresh liquid resin to vaporize the volatile liquid terpene components. It is semi-transparent and varies in color from yellow to black. At room temperature rosin is brittle, but it melts at stove-top temperature. It chiefly consists of various resin acids, especially abietic acid. The term “colophony” comes from colophonia resina, Latin for “resin from Colophon”, an ancient lonic city.

Production

Rosin is the resinous constituent of the oleo-resin exuded by various species of pine, known in commerce as crude turpentine. The separation of the oleo-resin into the essential oil (spirit of turpentine) and common rosin is accomplished by distillation in large copper stills. The essential oil is carried off at a temperature of between 100 °C (212 °F)° and 160 °C (320 °F), leaving fluid rosin, which is run off through a tap at the bottom of the still, and purified by passing through straining wadding. Rosin varies in color, according to the age of the tree from which the turpentine is drawn and the degree of heat applied in distillation, from an opaque, almost pitch-black substance through grades of brown and yellow to an almost perfectly transparent colorless glassy mass. The commercial grades are numerous, ranging by letters from A (the darkest) to N (extra pale), superior to which are W (window glass) and WW (water-white) varieties, the latter having about three times the value of the common qualities.

Tall oil rosin is produced during the distillation of crude tall oil, a by-product of the kraft paper making process.

When pine trees are harvested “the resinous portions of fallen or felled trees like longleaf and slash pines, when allowed to remain upon the ground, resist decay indefinitely.” This “stump waste”, through the use of destructive distillation or solvent processes, can be used to make products including rosin. This type of rosin is typically called wood rosin.

Because the turpentine and pine oil from destructive distillation “become somewhat contaminated with other distillation products”, solvent processes are commonly used. In this process, stumps and roots are chipped and soaked in the light end of the heavy naphtha fraction (boiling between (90 °C (194 °F) and 115 °C (239 °F)) from a crude oil refinery. Multi-stage counter-current extraction is commonly used so fresh naphtha first contacts wood leached in intermediate stages and naphtha laden with rosin from intermediate stages contacts unleached wood before vacuum distillation to recover naphtha from the rosin, fatty acids, turpentine, and other constituents later separated through steam distillation. Leached wood is steamed for additional naphtha recovery prior to burning for energy recovery. After the solvent has been recovered, “the terpene oils are separated by fractional distillation and recovered mainly as refined turpentine, dipentene, and pine oil. The nonvolatitle residue from the extract is wood rosin of rather dark color. Upgrading of the rosin is carried out by clarification methods that generally may include bed-filtering or furfural-treatment of rosin-solvent solution.”

On a large scale, rosin is treated by destructive distillation for the production of rosin spirit, pinoline and rosin oil. The last enters into the composition of some of the solid lubricating greases, and is also used as an adulterant of other oils.

Sources

The chief region of rosin production is Indonesia, southern China (such as Guangdong, Guangxi, Fujian, Yunnan and Jiangxi), and the northern part of Vietnam. Chinese rosin is obtained mainly from the turpentine of Masson’s pine Pinus massoniana and slash pine.

The South Atlantic and eastern Gulf states of the United States is also a chief region of production. American rosin is obtained from the turpentine of longleaf pine Pinus palustris and loblolly pine P. taeda. In Mexico, most of the rosin is derived from live tapping of several species of Pine trees, but mostly Pinus oocarpa, Pinus leiophylla, Pinus devoniana and pinus montezumae. Most production is concentrated in the west-central state of Michoacan.

The main source of supply in Europe is the French district of Landes in the Departments of Gironde and landes, where the martime pine P. pinaster is extensively cultivated. In the north of Europe, rosin is obtained from the Scots pine P. sylvestris, and throughout European countries local supplies are obtained from other species of pine, with Alppo pine P. halepensis being particularly important in the Mediterranean region.