How Glass is Made

Windows, vases, car windshields, computerof quality glass from the ingredients at the lowest
screens and picture frames – everywherecost possible.
you look it is almost a guarantee that somethingDifferent Glass Making Methods Used Today
in your line of vision will be made of glass.•Float Glass – This is the glass making
However, the only time we seem to notice it is ifprocess that is still used today and was pioneered
the windows need cleaning or we drop a wineby the British Pilkington brothers in the 1950s. This
glass and have to clean up the shards. Take amethod is the most cost-effective way to make
minute to think about what life would be likelarge sheets of glass for windows and doors. It
without this material and then learn a little bitinvolves floating the molten glass on a bed of
more about where it comes from and how itsmolten tin and as the glass is left to float
made.unhindered, it is essentially flattened by gravity
When Was Glass First Made?and its own weight, leaving the surface smooth
It is very difficult to pinpoint exactly when theand polished.
first piece of glass was manufactured, but•Plate Glass – This used to be the main
archaeological evidence suggests that it was asmethod for making large sheets of glass to be
far back as the second millennium BC. The beliefused in windows, doors and windshields before the
is that it was the Mesopotamians who firstfloat glass method was developed. A complicated
discovered the art of glass making and thetwin grinding and polishing process is involved that
substance was considered to be incrediblyis costly as well as wasteful. The long polishing
precious, even comparable to gold. When this artprocess needed to give the glass its sheen is time
reached the Egyptians, a method calledconsuming and creates excess glass shards that
core-forming was developed. A core made ofcan’t be reused.
clay and dung was moulded into a particular shape•Recycled Glass – Making recycled glass is
and the molten glass was wrapped around it anda great energy saver as its uses 40% less
then shaped by being rolled on a flat surface.energy than the process needed to make new
It was only by the first century BC that a newglass. This is because the crushed glass used in
method of glass making was developed andthe process melts at a much lower temperature
would change the face of glass production forthan the ordinary raw materials usually used to
ever more. Originating somewhere on the easternmake glass. Another benefit of recycled glass is
Mediterranean, possibly Syria, a hollow tube wasthat the materials can be used over and over
blown through allowing intricate shapes to beagain – the glass does not ever wear out.
created out of the molten glass gathered at the•Container Glass – This is the type of glass
end. This method soon became the favoured oneused to make bottles and jars and is usually made
amongst the Romans and its ease made glassup of soda-lime raw materials. Created through
products much more accessible to the commonblowing and pressing techniques, this is a fairly
people. After the Roman Empire fell, the art ofclean and natural glass making process, meaning
glass making lost its momentum in Europe untilthat this type of glass is easily recyclable. This
the popularity of stained glass arose in the 12thprocess involves three steps, the batch house,
century. It was from the 17th century onwardshot end and cold end. In the batch house step the
that glass making progressed the most steadilyraw materials are prepared and mixed, while the
and the use of furnaces eventually progressed tohot end involves the melting of the materials and
the float glass method that we still use today.their manipulation into the desired shape as well as
What is Glass Made From?the cooling procedures. The cold end involves
At its most basic level, glass is a brittle,inspecting the container glass for any defects,
transparent solid substance, while more technically,packaging them and labelling them for shipping.
it is an inorganic product of a fusion process which•Fibreglass – This is the other main type of
cools to rigidity without crystallising. The materialsglass besides sheet glass and container glass and
used in making glass vary depending on theis used mainly for thermal insulation and optical
desired function of the end result, for instancecommunication. This glass is made from
thicker glass or coloured glass requires slightlyexceptionally fine fibres of glass and is often used
different materials to be used in the initial process.as a reinforcing agent. The process to make
Most glass products are however made up of afibreglass is fairly complicated and usually starts
core set of basic materials, namely being sand,with the raw materials in solid form that are then
soda ash (sodium carbonate), dolomite, limestonemelted and sheared into fibres. The fibres are
and salt cake (sodium sulfate). The basic aim ofthen wound into a bobbin and turned into the
any glass maker is to get the maximum amountdesired fibreglass shape.