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Borosilicate Glass.
This type of glass was born into existence
in 1912 due to an unfortunate accident that took place eleven
years before on a rainy winter night in 1901. A signalman
(trackman) left the train station to warn the train’s
engineer that a freight train was approaching on the same
track he was on. He started to rotate his oil lamp sending
warning signals about the danger; unfortunately, the cold
rain hitting the hot lamp shattered the glass and the flame
was put off. Thus, the engineer could not see the signals
and the fatal accident took place.
To prevent such incidents, the search of a new type of glass,
thermal shock resistant, became of utmost importance. Experiments
using different materials to obtain such glass began to take
place immediately.
The truth was that the solution to fulfill such need had begun
to develop since 1846, when Carl Zeiss, a German precision
mechanic, set up a small workshop in Jena, Germany, where
he fabricated the lab equipment required by the university
of the same city. Years later, the physic Ernst Abbe was hired
to work as Zeiss assistant, who, with the elaboration of the
optical theory for microscopes, revolutionized the manufacture
of these instruments. Later, Dr. Otto Schott, a talented glass
chemist, joined this group of researches, and the three founded,
in 1884, the Jenaer Glaswerke factory.
When the company became Glastechnische Laboratorium Schott
& Genossen, during 1887, the discovery of the first borosilicate
formula was announced. Based on different experiments, this
lab researchers found out that if boron oxide was added to
the raw materials, the resulting glass could resist changes
in temperature, was harder to fuse and work with, and was
practically inactive.
The discovery made by the Schott & Genossen company, from
Jena (?), Germany, was later introduced in the United States
of America, where the researcher Corning tried to improve
it. Unfortunately, the breaking of World War I forced him
to postpone his work. However, by 1915 Corning had already
begun to market Pandrex glass for baking uses. Thanks to the
theory of this young researcher, it was established that glass
could be used for cooking due to its heat absorbent properties,
while many metals reflected heat.
Corning obtained, in most of the countries, the patent for
the manufacturing of Pandrex, launching mass production in
1922 in France and England. Due to the objections of the German
company that had originally discovered borosilicate glass,
in 1926 a market division agreement was reached stipulating
that Germany, Austria and the Eastern Scandinavian countries
would be an exclusive market for glass produced in Jena by
the Schott & Genossen company.
Now a day, borosilicate glass is used as lab material and
for the manufacturing of kitchen utensils known as “heat-resistant”,
which are backed by the firms Pandrex, Visions and Corning.
This type of glass shows a minor expansion rate with sharp
temperature changes due to a very low coefficient of expansion
of 30 to 42, depending on the type of the manufactured product.
Different types
of glass.
 Lime
Glass
Borosilicate
Glass
Optical
Glass
Tempered
or Safety Glass
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