Quote:
This is very interesting. What excatly is Rosin? This would be something I would like to try. Nice work mad scientist
A look on wikepedia gives this
Rosin, formerly called
colophony or
Greek pitch (
Pix græca), is a solid form of
resin obtained from
pines and some other
plants, mostly
conifers, produced by heating fresh liquid resin to vaporise the volatile liquid
terpene components. It is semi-transparent and varies in color from yellow to black. At room temperature it is brittle, but it melts at stove-top temperatures. It chiefly consists of different
resin acids, especially
abietic acid
Uses
Rosin is an ingredient in
printing inks,
varnishes,
adhesives (glues),
medicines,
chewing gum,
soap,
paper sizing, and, in past times,
sealing wax.
In industry it is the precursor to the
flux used in
soldering. The
tin-
lead solder commonly used in electronics has about 1% rosin as a flux core helping the molten metal flow and making a better connection. It's frequently seen as the burnt or clear residue around new soldering.
It is also extensively used for its
friction-increasing capacity. Such uses include rosining the
bows of
stringed instruments such as
violins or
cellos to produce sound. For this purpose, extra substances such as
gold and
silver are sometimes added to the rosin for extra friction and/or highly-disputed "tone improvements".
Ballet dancers sometimes rub their shoes in powdered rosin to reduce slipping before going on stage. Bull riders rub rosin on their rope and glove for additional grip.
Baseball pitchers and
ten-pin bowlers may have a small bag of powdererd rosin nearby, to use on their throwing hand, for better control of the
ball.
A mixture of
pitch and rosin is used to make a surface against which
glass is
polished when making optical components such as
lenses.
In
pharmaceuticals, it forms an ingredient in several plasters and ointments.
It is also added in small quantities to traditional
linseed oil/sand gap fillers, used in building work
Production
Rosin is also known as
colophony or
colophonia resina from its origin in
Colophon, an ancient
Ionic city. It 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 effected by
distillation in large copper
stills. The essential oil is carried off at a temperature of between 100° and 160° C, 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 whence the turpentine is drawn and the amount of heat applied in distillation, from an opaque almost pitchy 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.
On a large scale, it 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.
Though types of rosin may vary, there is no difference in quality. The types of rosin used in the playing of string instruments depends entirely on the preference of the player. The price varies according to how hard it is to procure the particular type.
Properties
Rosin is a
brittle and
friable, with a faint piny odor; the melting-point varies with different specimens, some being semi-fluid at the temperature of boiling water, while others melt at 100°C to 120°C. It is very flammable, burning with a smoky flame, so care should be taken when melting it. It is soluble in
alcohol,
ether,
benzene and
chloroform. Rosin consists mainly of abietic acid, and combines with caustic
alkalis to form salts (
rosinates or
pinates) that are known as rosin soaps. In addition to its extensive use in
soap making, rosin is largely employed in making inferior
varnishes, sealing-wax and various
adhesives. It is also used for preparing shoemakers'
wax, as a
flux for soldering metals, for pitching lager beer casks, for rosining the bows of musical instruments and numerous minor purposes.
Prolonged exposure to rosin fumes released during soldering can cause occupational
asthma (formerly called
colophony disease [1] in this context) in sensitive individuals, although it is not known which component of the fumes causes the problem.
[2]
sources
The chief region of rosin production is southern
China, such as
Guangdong,
Guangxi,
Fujian,
Yunnan and
Jiangxi, and Northern part of
Vietnam. Chinese rosin is obtained mainly from the
turpentine of
Masson's Pine Pinus massoniana and
Slash Pine P. elliottii.
The South Atlantic and Eastern Gulf states of the
United States is also the 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 (
gum rosin) of several species of
pine trees, but mostly
P. oocarpa,
P. leiophylla,
P. michoacana and
P. montezumae. Most production is concentrated in the west-central state of
Michoacán.
The main source of supply in Europe is the
French district of Les Landes in the departments of Gironde and Landes, where the
Maritime 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
Aleppo Pine P. halepensis being particularly important in the
Mediterranean region.
[] ´s
