sejal architectural glass limited - Securities and Exchange Board of ...

� Fused silica glass – Fused silica glass is a highly heat-shock resistant glass that consists
entirely of silicon dioxide. It is used in laboratory glassware and optical fibers. It consists of
a special borosilicate composition that has been made porous by chemical treatment.
Uses of Glass
� Flat glass is used chiefly in windows. It is also used in mirrors, room dividers and furniture.
All flat glass is made in the form of flat sheets. But some of it, such as that used in
automobile windshields, is re-heated and curved over moulds.
� Glass containers are used for packaging of food, beverages, medicines, chemicals and
cosmetics. They are made from special glass formulas to make sure there will be no
contamination or deterioration of blood plasma, serums, and chemicals stored in them.
� Optical glass is used in eyeglasses, microscopes, telescopes, camera lenses and other
instruments for factories and laboratories. The raw materials used to make optical glass
must be pure. The care required for producing optical glass makes it expensive.
� Fiberglass consists of fine but solid rods of glass, each of which may be less than one
twentieth the width of a human hair. Glass fibres are loosely packed together in a woollike
mass that can serve as heat insulation. They are also used like wool or cotton fibres to
make glass yarn, tape, cloth and mats. Fiberglass also finds applications in electrical
insulation, chemical filtration, and fire fighters’ suits. Combined with plastics, fiberglass is
used for airplane wings and bodies, automobile bodies, and boat hulls. It is a popular
curtain material because it is fire-resistant and washable.
� Specialty glasses are all other types of glass besides flat glass, glass containers, optical
glass and fiber-glass. Laminated safety glass, bullet-resisting glass, opal glass, coloured
structural glass, laser glass are some of the kinds of specialty glass
Float Glass
The preferred method of glass manufacturing is through what is known as the Float Process.
This differs from the old way of making glass which is known as the Drawn Sheet method. In the
drawn sheet process, sheets are literally drawn out of a vat of molten glass. The result is an
inferior glass which is optically impure. The float process entails melting recycled glass, called
cullet, silica sand, potash, lime and soda in a furnace. The molten glass is pushed through an
opening onto a bed of molten tin, where it cools as it travels along to be cut into sheets. The
speed that the molten glass travels at determines its thickness.
The type of float glass used can be broadly divided into the following:
� Clear glass: This type of glass is very widely used. It is processed further into mirrors,
beveled and etched.
� Tinted glass: Tinted glass is manufactured by adding a dye at the molten glass stage. This
is used to minimise solar heat gain and glare while it also absorbs heat, the primary use
being in interiors – table tops, counter tops, windows, etc. To a limited extent, this is also
used in curtain walling.
� Reflective glass: Float glass can be treated with a metallic coating which provides a
reflective mirror type effect. This is particularly advantageous should the reduction of solar
heat gain be desirable. The major use of reflective glass is in curtain walling and structural
glazing. This is available in various shades of grey, blue, green etc.
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