Function
The pencil is a writing instrument that can also be used for drawing, but unlike the pen, it writes with graphite. The eraser on the back erases the graphite marks that the pencil makes by rubbing it off of the paper.
Major Materials
The major materials that make up a modern pencil are:
· Wood, used to hold the writing core can be Incense-cedar, tropical rainforest wood, or can be made of plastic.
· Graphite, the writing core. It makes a dark black mark on paper, and wears away pretty quickly. It is very breakable, so it has to be in a protective holder.
· Clay, a substance that pencil-makers mix with graphite to adjust the pencil’s hardness.
· Rubber eraser, today's pencil erasers are made from either a synthetic rubber compound or from vinyl. Pink erasers are made from synthetic rubber blended with pumice (a grit that enhances its ability to erase), and vinyl is a type of durable, flexible plastic.
· The metal ring, or ferrule that is used to hold the eraser is made up of zinc and copper to create a strong, but bendable brass holder.
· The last and least important part of the modern-day pencil is paint. It is made up of a synthetically prepared material.
Why these materials were chosen
Wood is chosen to hold the writing core in place since it is very strong, yet easily sharpened. Plastic has all the same features, and it is also bendable. Wood can easily break and plastic is not that easy destroy. The plastic material though sharpens less easily than wood, though.
Graphite was picked because when the Romans used lead for the core, it caused a lot of health problems, so when graphite was discovered, it appeared the more safe way of writing, and left a darker mark.
Clay is hard, and doesn’t leave that much of a mark. So if you add it to graphite it can adjust the hardness and color intensity of the pencil.
Synthetic rubber can be made for the eraser because it has an ability that allows it to erase very easily and quickly, and vinyl is very durable and flexible, and also erases pretty neatly, although not as neat as the synthetic rubber does.
The zinc ferrule was chosen, because of its high flexibility and incredible strength. It is probably the best material to hold an eraser.
Paint protects the wood from decomposition and gives the pencil a nice modern look.
Origin of one of the materials
Probably the most important material in the pencil is the writing core, or graphite “lead”. Graphite came into widespread in the 16th century, following the finding of a large graphite deposit in
History of the object.
In ancient
Graphite left a dark mark, making it perfect for use by writers and artists. But it was so soft and brittle that it required a holder. At first, sticks of graphite were wrapped in string. Later, the graphite was inserted into wooden sticks that had been hollowed-out by hand! The wood-cased pencil was born.
The first mass-produced pencils were made in
Bibliography
The pencil pages. Doug Martin, Web manager. 2002
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Pencils. The
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Petroski, Henry. The Pencil: A History of Design and Circumstance.
Dr. A.S. Bailey, “Graphite.” Family Encyclopedia. 1997 1st ed.
Arthur Van Der Kar, “Pens and Pencils: Pencils” The
Polymer Clay Pencils. Heaser, Sue, web manager 14th October 2002.
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