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铅笔是大家从小用到大的东西。不知道你用铅笔的时候有没有想过它到底是怎么来的。想了解一下铅笔是谁发明的和怎么制作的吗?赶快看看下面这篇文章吧!
Pencil, a derivative of the Latin word pencillus for "little tail,"
originally described a small, fine, pointed brush.
N. J. Conte, in 1795, successfully produced pencils, after the later famed
Faber family of Nuremberg, Germany, failed to do so, by using
apulverizedgraphite base to create a substandard, crude prototype of a pencil.
Conte's method, the basic recipe used by all pencil manufacturers today,
differed from the failed Faber fiasco, as he groundgraphite, mixed it with
certain types of clay, pressed the "dough" into sticks, and finished them in
akiln. The Faber family followed suit, and achieved the fame and fortune that
previously eluded it.
The recipe used by modern pencil manufacturers, calls for dried, ground
graphite, a form of carbon, mixed with clay and water in varying proportions.
Pencils made with more clay produce a harder pencil, and, conversely, pencils
made with more graphite produce a softer pencil. In either case, the ingredients
are mixed until they reach adoughyconsistency, and then pass through a forming
press, which presses the dough into a pencil thin, smooth, glossy rope. After
workers straighten the rope they cut it into the desired lengths, and bake them
in industrial ovens.
While the mixture is prepared and baked, workers prepare the casing that
will house the lead. They shape the wooden casings, made from either red cedar
or pine, into halves, and carve grooves in them to encase the graphite-based
leads. The workers then carefully insert the finished leads into the grooves,
glue the two wooden halves together, run the resulting slats through a saw that
cuts them into single pencils, and finish them with a shaping machine that
smoothes the pencils' surfaces.
Modern pencils come in over 350 varieties; each designed for a specific
use, and may be purchased in over 72 colors. Black pencils, or graphite-based
pencils, come in 19 degrees of hardness and of intensity. Specialty pencil leads
are crafted to write on surfaces such as cloth, cellophane, plastics, and movie
film. Architects, engineers, and those doing outdoor construction work primarily
purchase these specialty leads, as they possess non-fade, weatherproof
qualities. The versatility of Conte's brainchild, the pencil, makes it the
essential, indispensable tool of these trades.
pulverize: 研磨成粉
graphite: 石墨
kiln: 窑，干燥炉
doughy: 面团似的 |
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发表于 2016-7-9 23:45:05