3. INTRODUCTION
Glass has been a fascinating material to humankind since it was first made
in about 500 BC. At first thought to possess magical properties, glass has
come a long way. It is one of the most versatile and oldest materials in the
building industry. From its humble beginnings as a window pane in luxury
houses of Pompeii to sophisticated structural members in new age
buildings, its role in architecture has evolved over the years.
4. history
The Beginning:
Archeological findings indicate the Stone Age man used naturally formed
glass in his everyday activities.
Pliny, the ancient Roman historian, recorded that man became aware of
produced glass probably about 5000 BC in Syria.
3500 BC:
Glass beads seem to be the first objects made from glass around 3500 BC in
Egypt and Mesopotamia.
1500 BC – Egypt:
About this time, Egyptian glassmakers made hollow glass forms by dipping a
core mold made from compacted sand into molten glass which coated the
mold.
The sand core was removed after the glass had cooled.
5. 25 BC – Syria:
The process of glass blowing involves placing glob
of molten glass on the end of a metal tube
through which the glass maker would blow and
produce a hollow form with his breath was
created.
The Romans took the process farther by blowing
the glass into molds.
1271 AD – Venice:
Venice became a major producer of glass, but
because of the frequency of fires from the
numerous glass furnaces, the government ordered
the glass makers to the island of Murano.
1688 – France
France discovers the process of
pouring molten glass on to special
tables to produce a uniform thin
piece of glass.
They also coated some of the
glass with a low temperature
metal and produced mirrors.
1100 AD – Gothic Art:
Glass sheets became more available
through the process of blowing.
These pieces of flat glass were limited in
size so they were joined together using lead
strips.
Glass windows though were very expensive
6. 1910:
Safety glass, found in all cars today, is introduced.
By sandwiching a clear plastic between two layers of glass, the glass might crack but will
not shatter making glass a lot safer.
Today’s:
Glass today is not finished evolving. Computer control, special coatings, refractory
glass, microelectronics, and creative innovations promise all kinds of potential for
glass and the future.
In 2012 a new type of ultra thin glass has been developed that has a ability to wrap
round devices.
1875:
Michael Owens invents an
automatic bottle blowing
machines.
Decorative art glass became
popular about this time with
famous names like Tiffany and
Stueben
8. Manufacturing
Depending upon the type of glass to be manufactured,
suitable raw materials are collected.
Collection of Raw
Materials:
The raw materials, cullet and decolouriser are finely
powdered in grinding machines.
These materials are mixed until a uniform mixture is
obtained.
Such a uniform mixture is known as the batch or frit and it is
taken for further process of melting in a furnace.
Preparation of
Batch:
9. Melting in
Furnace:
Pot Furnace:
Pots are placed in specially prepared holes in the
furnace.
The charging and collecting doors are kept projecting
outside.
The pots are filled with raw materials and heated by
means of producer gas.
When the mass has melted down, it is removed from the
pot and it is taken for the next operation of fabrication.
Tank Furnace:
The ports are provided for preheated producer gas.
The doors are provided for charging and for taking out the molten
glass.
It flows through opening of bridge into small compartment.
The tank is filled with raw materials and heated by allowing producer
gas through ports.
This is a continuous process and it is adopted to melt large quantities of
glass at a time.
10. Fabrication:
The molten glass is given suitable shape or form in this stage. It can either be done by
hand or by machine. The hand fabrication is adopted for small scale production and
machine fabrication is adopted for large scale production.
Following are the different ways of fabrication:
(i) Blowing
(ii) Casting
(iii) Drawing
(iv) Pressing
(v) Rolling
(vi) Spinning.
The process of slow and homogeneous
cooling of glass articles is known as the
annealing of glass.
Following are the two methods of annealing:
(i) Flue treatment
(ii) Oven treatment.
Annealing:
11. TYPES OF GLASSES
1. Principal Type:
Soda lime glass
Potash lime glass
Potash lead glass
Common glass
Borosilicate Glass
2. Processed glasses:
Lacquered glass
Frosted glass
Chromatic glass
Toughened glass
Insulated Glazed Units
Laminated glass
3. Normal glasses:
Float glass
Shatterproof glass
Patterned glass
Extra clean glass
Wired glass
12. Soda Lime Glass:
• Soda lime glass is also known as soda ash glass,
soda glass, commercial glass or soft glass which is
obtained from the fusion of a mixture of silica,
lime, soda and alumina.
• It is widely used for glazing of doors, windows,
and for making ordinary glass wares.
Potash Lime Glass:
• It is also known as hard glass, or Bohemian glass.
• Potash lime glass is similar to soda lime glass except
that soda is replaced by potash.
• It is used for making laboratory apparatus and
combustion tubes.
Potash Lead Glass:
• It is also known as flint glass or lead glass.
• It is obtained from the fusion of a mixture of silica,
lead, and potash.
• Lead glass is used for high quality glassware, cut
glass, bulbs, lenses and prisms.
Soda lime glass
Potash lime glass
Potash lead glass
Common glass
Borosilicate Glass
Principal type
13. Common Glass:
• Common glass also known as bottle
glass
• It is prepared from cheap raw materials
like sodium silicate, silicate, calcium
silicate.
• It may be green, brown or yellow in
colour.
• Common glass is mainly used in the
manufacture of household and
medicine bottles.
Borosilicate Glass:
• Borosilicate glass is also known as Pyrex
glass.
• It is obtained from the fusion of silica, borax,
lime, and feldspar.
• Borosilicate glass is used for making
laboratory equipment and cooking utensil
since it can withstand high temperature.
14. Glass Bending:
• Glass bending is a process in
which, rods, sheets or tubes
of glasses are bent into the
desired shape by placing
them in temperature
controlled ovens.
• They are heated to suitable
temperature and bent into
the desired shape.
Glass Opaque making or Glass
Etching:
• It can be made opaque
mechanically by grinding
the surface by emery.
• The surface of the glass can
also be made opaque
chemically by the
application of hydrofluoric
acid. It is also known as
glass etching.
Glass Cutting and
Grinding:
• The glass is cut in
required size and
shape with the help
of either a diamond
cutter or rough glass
or small wheels of
hardened steel.
• The glass cutting is
also done by laser
based technology.
Glass Silvering:
• Glass silvering consists of a
very thin coat of tin on the
surface of the glass. The
silver is deposited on this
layer of tin. The silvered
surface is protected by
applying a suitable paint
over it.
• Fire polishing is another
way to glass treatment. It is
called as hydropox flame
treatment.
TREATMENT
15. After the treatment of glass the
following types of glasses are made:
1. Processed glasses:
Lacquered glass
Frosted glass
Chromatic glass
Toughened glass
Insulated Glazed Units
Laminated glass
2. Normal glasses:
Float glass
Shatterproof glass
Patterned glass
Extra clean glass
Wired glass
Tinted glass
16. Lacquered Glass:
• Lacquered glass also known as back painted glass.
• It is obtained by painting the back surface of the
glass with high quality paint.
• Back painted glass is extensively used in
architectural spandrels, furniture, kitchen
countertops, backsplashes, washrooms of
cinemas, hotels, restaurants, etc.
Frosted Glass:
• One surface of the glass is etched and has a rough
finish, through which diffusion of light occurs.
• Frosted glass is used as a decorative glass where
privacy is required, such as shower cubicles,
conference rooms, office partitions, windows and
doors of bedrooms, dressing rooms, etc.
Chromatic Glass
• Chromatic glass is used in ICU’s, meeting rooms etc.
• It can control the transparent efficiency of glass and
protects the interior from daylight.
• The chromatic glass may be photochromic which has
light sensitive lamination, thermos-chromatic which
has heat sensitive lamination and electrochromic
which has electric lamination over it.
Lacquered glass
Frosted glass
Chromatic glass
Toughened glass
Insulated Glazed
Units
Laminated glass
PROCESSED
GLASS
17. Toughened Glass
• Toughened glass is strong glass
which has low visibility.
• It is available in all thicknesses
and when it is broken it forms
small granular chunks which are
dangerous.
• This is also called as tempered
glass.
• This type of glass is used for fire
resistant doors, mobile screen
protectors etc.
Laminated Glass
• Laminated glass is the
combination of layers of
normal glass.
• It has more weight than
normal glass.
• It has more thickness and is
UV proof and soundproof.
• These are used for
aquariums, bridges etc.
Insulated Glazed Units
• Insulated glazed glass units contains
a glass is separated into two or
three layers by air or vacuum.
• They cannot allow heat through it
because of air between the layers
and acts as good insulators.
• These are also called as double
glazed units.
18. Float Glass
• Float glass is made of sodium silicate and calcium
silicate so, it is also called as soda lime glass.
• It is clear and flat so, it causes glare.
• These glasses are available from 2mm to 20mm
thickness ranges.
• These are used as shop fronts, public places etc.
Shatterproof Glass
• Shatterproof glass is used for windows, skylights,
floors etc.
• Some type of plastic polyvinyl butyral is added in its
making process.
• It cannot form sharp edged pieces when it breaks.
Patterned Glass or Textured Glass:
• It is a decorative and translucent glass with textures
or patterns on one face of the glass for diffusing light
and obstructing visibility from the outside.
• Patterned glass is useful for providing privacy to
interiors of the house, thus extensively used in
exterior windows and bathroom windows.
Float glass
Shatterproof glass
Patterned glass
Extra clean glass
Wired glass
Tinted glass
NORMAL
GLASS
19. Extra Clean Glass
• Extra clean glass has two special
properties, photocatalytic and
hydrophilic.
• Because of these properties, it acts
as stain proof.
• It gives beautiful appearance.
• Maintenance is also easy.
Wired Glass:
• Wire mesh is inlaid in the glass
to protect from shattering and
breaking out under stress.
• Wired glass is low cost fire
resistance glass.
• It is used to protect against the
harmful effects of smoke and
flame.
Tinted Glass
• Tinted glass is nothing but colored glass.
• A color producing ingredients is mixed to the normal
glass mix to produce colored glass which does not
affect other properties of glass.
Coloring ion Color
Iron oxide Green
Sulphur Blue
Manganese dioxide Black
Cobalt Blue
Chromium Dark green
Titanium Yellowish brown
Uranium Yellow
Different color producing ingredients are tabulated below:
20. Glass block :
• Glass block or glass bricks are manufactured from two different halves
• They a re pressed and annealed together while melting process of glass.
• These are used as architectural purpose in the construction of walls,
skylights etc.
• They provide aesthetic appearance when light is passed through it.
Obscure glass:
• This type of glass is one that reduces the level of visibility through the
pane.
• The upside is you can limit how much is visible through the glass to gain
privacy into a bathroom, for example.
Bullet-proof glass:
• This glass is made of several layers of plate glass and alternate layers
consist of vinyl-resin plastic.
• The outer layers of plate glass are made thinner than the inner layers.
• The thickness of this type of glass may vary from 15 mm to 75 mm or
more.
Fibre glass:
• The fibre glass is composed of minute glass rods
• It is soft to the touch and it is flexible in nature.
• It does not absorb water and it is proof against fire, vermins, water and
acids.
SPECIAL
VARITIES
FIBRE GLASS
BULLETPROOF
GLASS
21. Heat Resistant Glass
• Heat-resistant glass is commonly consisting of a soda lime or silica that
is a heat-resistant material, with a very low expansion coefficient and a
high melting point.
• Heat resistant glass is a type of glass that is designed to resist thermal
shock.
• This glass is believed to be better than any other ordinary glass
available.
Structural glass
• The term 'structural glass' is a wide-reaching product term used to
describe a frameless glass assembly where the glassis taking an
element of the structural load.
• The structuralload that the glass is designed to take will depend on the
location and purpose of the glass element.
Foam Glass
• Foam glass takes cullet and one or two types of adjuvant (foaming
agent, limestone, calcium carbide, or coke) as the raw material. After
grinding, blending, and fitting die, the raw material is roasted
• The foam glass has the properties of low thermal conductivity, high
compression strength, and better durability.
• This material can be used to build walls, regulate heat in refrigerating
equipment, or used as floating and filtering material
.
HEAT RESISTANT
GLASS
22. Transparency:
: This property allows visual
connection with the outside
world.
It can be permanently altered
by adding admixtures to the
initial batch mix.
By the advent of technology
clear glass panels used in
buildings can be made
opaque.
Strength:
Glass is a brittle material
certain laminates and
admixtures can increase
its modulus of rupture(
ability to resist
deformation under
load).
U value:
The U-value is the
measure of how much
heat is transferred
through the window.
The lower the U-value
the better the insulation
properties of the glass–
the better it is at
keeping the heat or cold
out.
Greenhouse effect:
The greenhouse effect refers to
circumstances where the short
wavelengths of visible light from the
sun pass through glass and are
absorbed, but the longer infrared re-
radiation from the heated objects
are unable to pass through the glass.
This trapping leads to more heating
and a higher resultant temperature.
PROPERTIES
23. Workability:
It can be blown, drawn or
pressed.
It is possible to obtain glass
with diversified properties-
clear, colorless, diffused and
stained.
Glass can also bewelded by
fusion.
Recyclable:
Glass is 100%
recyclable, cullets (Scraps of
broken or waste glass
gathered for re-melting) are
used as raw materials in
glass manufacture, as
aggregates in concrete
construction etc.
Solar heat gain
coefficient:
It is the fraction of
incident solar radiation
that actually enters a
building through the
entire window assembly
as heat gain.
Energy efficiency and
acoustic control
Energy-efficient glazing is the term
used to describe the double glazing or
triple glazing use in modern windows
in homes.
Energy-efficient glazing incorporates
coated glass to prevent heat escaping
through the windows.
The air barrier also enhances acoustic
control.
24. From the beginning of 20th century modern
architecture has been instrumental in mass
production of concrete, glass and steel
buildings in the factories we call cities. Glass
and steel construction have become the
symbol of development in many countries,
where people tend to see these buildings as
symbols of affluence and luxury.
APPLICATIONIN BUILDING
25. 01.Visible Transmittance:-Glass absorbs, refracts or transmits light.
02. Weather and Rust Resistant:-The glass is fully weather resistant so it can
withstand the effects of the wind, rain, or the sun
.
03. Dustproof and Waterproof:-Glass has a smooth glossy surface, so it is dustproof
04. Transparency:-The glass allows you to connect with the outer world visually
05. Insulator of Electricity:-It is an excellent insulator against electricity.
06. Easily Moulded:- It can be blown, drawn and pressed to any shape.
07. Aesthetically Appealing:-Glass can make the structure look more stunning, sophisticated and
adds beauty to the building
08. Recyclable:- Glass is 100% recyclable, and it does not degrade during the recycling process.
09. Sustainable Material:-The integrated system of recycling provides cost-savings and a reduction in
carbon footprint.
10. UV Stable:-The glass is UV stable since it is not attacked by ultraviolet radiation and hence
cracks, discolouration or disintegration will not occur.
11. Abrasion Resistance:-The glass is excellent abrasion resistant material so it will resist surface
wear caused by flat rubbing and direct contact with another material.
ADVANTAGES
26. 01.Cost:- It is an expensive material that ultimately adds to the cost of construction.
02. Brittleness:- Broken pieces of glass may be sharp, and chances of injury are very high.
03. Impact Resistant:-The Glass is less impact resistant, so the capability of the glass to withstand an
immediately applied load is very poor.
04. Etching on Glass surface:-The Glass is affected by external hydrofluoric acid, and hence etching
appears occasionally on the glass surface.
05. Corrosion Due to Alkali Solution:-The Glass is affected by alkalis ions. Alkali solution dissolves
a glass surface, and as long as the supply of alkali is sufficient, this type of corrosion takes place at a
uniform rate.
06. Unsafe for Earthquake-prone Areas:- There is no such Glass which could be an earthquake-
proof material, but the costly treatment makes it withstand
against earthquake.
07. Low Heat Preservation:- The glass is inadequate in terms of heat preservation, leading to higher
costs in the operation of air-conditioners.
08. Maintenance:-Though many feel that once you provide glass as a building façade, you need not
spend much on painting expenses
.09. Not suitable for Hot Climate Areas:-Glass absorbs heat and hence acts as a greenhouse, thus
trapping the heat. Therefore, it is not ideal in warm and hot climates.
disADVANTAGES
