Glass has been manufactured since 4000BC, initially by hand but now through mechanized processes. The key raw materials used are sand, soda ash, limestone, and dolomite. In modern glass production, these materials are melted together at high temperatures, then floated on molten tin to form smooth, bubble-free sheets. The glass sheets are coated, gradually cooled through annealing, cut to size, and inspected to ensure quality.
2. History & applications
Archaeologists have
found evidence of
man-made glass
which dates back to
4000BC.
They are used in car
doors, windows,home
appliances,lights,etc.,
3. Manufacture
In olden days glasses are made by
hand.
They take long time and more man
power.
Now-a-days making of glass are
machinated.
From olden days to now,sand is the
important raw material in making
glass.
4. Raw materials
Sand
SAND SODA ASH
(grade A to G)
Soda ash
Lime stone LIME STONE DOLOMITE
Dolomite
Alumina ALUMINA
5. PROCESS
MELTING AND REFINING,
FLOAT BATH,
COATING,
ANNEALING,
INSPECTION,
CUTTING.
6. MELTING & REFINING
The raw materials are
mixed and melted in gas
furnace up to all the raw
materials are completely
melted.
In this process impurities
are come upwards & they
are removed.
It will take 50 hours to melt.
Capacity of furnace is 2000
tones.
7. Float bath
Molten glass float through tin.
Glass enters the bath at 1,100
degree and leave the bath at
600 degree Celsius.
Because tin more denser than
glass,glass float on them &
they form smooth and bubble
less flexible glass at last.
8. coating
After float bath &
In this stage glass is coating
called ribbon glass.
Variety of chemicals are
coated at thickness of less
than micron based on it's
purpose.
This process is
called chemical
vapor deposition
(CVD)
9. Annealing
Annealing means cool
down the substance
by slow and steady
process.
Glass will broke when
cooled suddenly, so it
will be gradually
cooled to normal
temperature.
After this process we
get a fine smooth
glass plate.
10. Cutting & quality control
These glass plate are cut into proper size using
diamond cutter.
After this all the glass plates are check for its quality
and optical view.
