PencilA pencil is a handheld instrument used to write and draw, usually on paper. The writing is done with graphite (except for coloured pencils), which is typically covered by a wooden sheath. Pencils may also have an eraser or “rubber” attached to one end.
The first kind of pencil may have been the ancient Room stylus, which was a thin metal stick used for scratching on papyrus, often made of lead. The word pencil comes from the Latin word “penicillus” which means “little tail”.
In 1564, a very large deposit of graphite was found at the site of Seathwaite Fell near Borrowdale, Cumbria, England. The locals found that it was very useful for marking sheep. This particular deposit of graphite was extremely pure and solid and it could easily be sawed into sticks. This was remains the only deposit of graphite ever found in this solid form. Chemistry was in its infancy and the substance was thought to be form of lead. Because of this, it was called “lead”, even though it does not contain the element lead.
Picture : Graphite
Soon, people realized that plumbago was worth a lot, mainly because it could be used to lint the moulds for cannon balls and the mines were taken over by the Crown and guarded. Graphite had ti be smuggled out for use in pencils. Because the plumbago was soft, it required some form of case. Plumbago sticks were at first wrapped in string or in attracting the attentions of artists all over the known world.
In 1761 cabinetmaker Kaspar Faber settled in Stein, near Nurenburg, in Germany to make his first sample pencils. Graphite was cut into narrow sticks and glued between two pieces of wood which were cut and planed smooth. The family dynasty of pencil makers had begun.
In 1839 Lothar Faber, the great grandson of Kaspar Faber, began to transform the pencil industry. He mechanized production, using first water, then steam power and achieved a production rate and consistency of quality previously unheard of. He invented the hexagonal pencil and created standards for pencil size and grades of hardness still in use today. His products were marked A.W. Faber, the first ever brand name writing product and amongst the earliest branded articles in the world.
Today, the Faber-Caster Group produces approximately 1.8 billion wood cased pencils per year and is the world’s largest pencil manufacturer.
Wood Holder Added
Italian was the first thought of wooden holders, at first by hollowing out a stick of juniper wood. Shortly after that, a better technique was discovered. Two wooden halves were carved, a plumbago stick put in, and two halves then glued together – almost the same method that is used today.
Picture : The oldest pencil: found during renovation work.
English and German pencils were not available to the French during the Napoleonic wars. In 1975, Nicholas Jacques Conté discovered a method of mixing powdered graphite with clay and forming the mixture into rods that were fired in a kiln. By varying the ration of graphite to clay, the hardness of the graphite rod could also be varied. This method manufactures which had been earlier discovered by Austin Joseph Hardtmuth of Koh-I-Noor in 1790 remains in use.
The hardness of a pencil depends on how much clay is keeping the graphite together (clay is used as a binder). The dark pencil mark means the pencil has deposited more particles of graphite onto the paper.
The Manufacturing
Today, we still call the core of a pencil the “lead” even though it is made from nontoxic graphite.
Today, pencils are made industrially by mixing finely ground graphite and clay powders, adding water, forming long spaghetti-like string, and firing them in a kiln. The resulting strings are dipped in oil or molten wax which seeps into the tiny holes of the material, resulting in smoother writing. A juniper or incense-cedar plank with several long parallel grooves is cut to make something called a slat, and the graphite/clay strings are inserted into the grooves. Another grooved plank is glued on top, and the whole thing is then cut into individual pencils, which are then varnished or painted.
Picture : The top sequence shows the old method that required pieces of
graphite to be cut to size; the lower sequence is the new, current method
using rods of graphite and clay.
Picture : Show the eraser being attated to one end of the pencilMany pencil are labeled on the European system using a scale from “H” (for hardness) to “B” (for blackness), as well as “F” (for fine point). The standard writing pencils is “HB”.
Pencils graded using this system is used to measure the hardness and resistance of varnishes and paints. The resistance of a coating (also known as its pencil hardness) is determined as the grade of the hardest pencil that does not mark the coating when pressed firmly against it at a 45 degree angle.
For more information about pencil please log on to :
http://en.wikipedia.org/wiki/Pencil#Colour_of_pencils
