The document provides a comprehensive overview of glass, including its definition, properties, historical development, manufacturing processes, types, and various applications. It highlights the advantages and disadvantages of glass in construction and other uses, emphasizing its utility and challenges. Different types of glass, such as soda-lime, lead, and tempered glass, are detailed along with their specific uses and characteristics.

2. Glass

3. Contents
* What is glass
* Structure of glass
* History
* Types of glass
* Properties of glass
* Manufacturing of glass
* Uses of glass
* Advantages of glass
* Disadvantages of glass

4. What is glass
“Glass is a an inorganic product of fusion which
has cooled to a rigid condition without
crystallization”
or
A brittle transparent solid with irregular atomic
structure

5. Molecular structure of glass

7. Glass is an inorganic solid material that is usually clear
or translucent with different colors. It is hard, brittle,
and stands up to the effects of wind, rain or sun. Glass
has been used for various kinds of bottles and
utensils, mirrors, windows and more. It is thought to
have been first created around 3000 BC, during the
bronze age. Egyptian glass beads date back to about
2500 BC.
History

8. History of most useable glass products
Brief History:
• Bottles (3500 years)
• Windows (2000 years)
• Telescope & Microscope Lenses (1590
Netherlands)
• Mirrors(1680 France)
• Light Bulbs (1926)
• Float Glass (Pilkington , 1959)
• Glass Laser (1960)
• Optical Fiber (1970)
Egypt, 1400-1360 B.C.
Telescope Mirror, College of Optical Sciences

9. These are the main characteristics of glass:
- Solid and hard material
- Disordered and amorphous structure
- Fragile and easily breakable into sharp pieces
- Transparent to visible light
- Inert and biologically inactive material.
-Glass is 100% recyclable and one of the safest
packaging materials due to its composition and
properties
-
Properties of Glass

10. MANUFACTURING OF
GLASS

11. THE FLOAT PROCESS

12. Sand, soda ash, dolomite, limestone and a
proportionate amount of cullet
Raw material
Furnace
Raw material feed
1600 °C

13. Float bath
Tin Surface
High specific gravity
Immiscible into the molten glass
1100 °C--600°C

14. Annealing
one end hot & one cold
Slow cooling
600°C-200°C
internal stress

15. Inspection
Cutting to order
In desired pieces

17. Production of glass bottles

19. Types of glass

20. 1. Commercial glass or Soda-lime glass:
This is the most common commercial glass and less
expensive. The composition of soda-lime glass is
normally 60-75% silica, 12-18% soda, and 5-12%
lime. A low percentage of other materials can be
added for specific properties such as coloring.

21. Soda-Lime Glass

22. 2. Lead glass:
This type of glass is composed of 54-65% SiO2, 18-38%
lead oxide (PbO), 13-15% soda (Na2O) or potash (K2), and
various other oxides. When the content of PbO is less than
18% is known as crystal glass.

23. Lead Glass

24. 3. Borosilicate glass:
This is glass mainly composed of silica (70-80%), boric oxide B2O3
(7-13%) and smaller amounts of the alkalis (sodium and potassium
oxides) such as 4-8% of Na2O and K2O, and 2-7% aluminum oxide
(Al2O3). Boron gives greater resistance to thermal changes and
chemical corrosion.

25. Borosilicate Glass

26. 4. Laminated glass (Safety Glass):
This is a type of safety glass that holds together when
shattered. It typically has 2 layers of thick commercial glass
with a layer of resin called PVB (Polyvinyl Butaryl), between
them. In the event of breaking, the interlayer keeps the
layers of glass bonded even when broken, and its high
strength prevents the glass from breaking up into large sharp
pieces. This produces a characteristic "spider web" cracking
pattern when the impact is not enough to completely pierce
the glass.

27. Laminated Glass

28. 5. Tempered Glass (Safety glass):
Tempered glass is four to five times stronger than standard glass
and does not break into sharp shards when it fails. Tempered glass
is manufactured through a process of extreme heating and rapid
cooling, making it harder than normal glass.
• The brittle nature of tempered glass causes it to shatter into small
oval-shaped pebbles when broken. This eliminates the danger of
sharp edges. Due to this property, along with its strength,
tempered glass is often referred to as safety glass.

29. Tempered Glass

30. Uses of glass

31. •Soda-lime glass is primarily used for bottles, jars, everyday drinking
glasses, and window glass.
•Lead glass is usually used for art glass, wine and champagne glass, etc.
Glass with high lead oxide contents (i.e. 65%) may be used as radiation
shielding glass because lead absorb gamma rays and other forms of
harmful radiation, for example, for nuclear industry.
• It is suitable for industrial chemical process plants, in laboratories, in
the pharmaceutical industry, in bulbs for high-powered lamps, etc.
Borosilicate glass is also used in the home for cooking plates and other
heat-resistant products. It is used for domestic kitchens and chemistry
laboratories, this is because it has greater resistance to thermal shock
and allows for greater accuracy in laboratory measurements when
heating and cooling experiments

32. •Laminated glass is normally used when there is a possibility of
human impact or where the glass could fall if shattered. Shop-front
glazing and windshields are typically laminated glasses. The PVB
interlayer also gives the glass a much higher sound insulation rating,
due to the damping effect, and also blocks 99% of transmitted UV
light.
•The thermal process that cures tempered glass also makes it heat
resistant. Tempered glass is used to make the carafes in automatic
coffee makers and the windows in ovens. Computer screens,
skylights, door windows, tub enclosures and shower doors are more
examples of places you will find tempered glass. Building codes also
require the windows of many public structures to be made of
tempered glass.

33. Advantages
1. glass in construction work adds beauty to the building.
2. Its use fulfills the architectural view for external decoration.
3. By using glass in interior, it saves the space inside the building.
4. Glass cladding in building fulfill functional requirement of
lighting, heat retention and energy saving.
5. Its use appear a sense of openness and harmonious.
6. As toughened glass is available, one can have good interior
design with the use of glass in transparent staircase, colored
shelves, ceiling etc.
7. Glass is an excellent material for thermal insulation, water
proofing and energy conservation.
8. Glass is bad conductor of heat; it saves energy in air
conditioning of building.
9. For making glass partition on upper floors, no extra design is
required for slab as glass is light in weight.

34. • Difficult to work with if irregular shapes are needed.
Glass is malleable only when heated and treated in
special kilns and by special tools. By comparison, some
metal can be bent while cold and retain their strength
and new shape. [Glass bricks, however, can be used to
create irregular shapes in much the same way clayey
bricks are used.
• Glass in high buildings is a constant threat to people
below who might be underneath a falling glass pane or
its shards. This is a not infrequent happening during
earthquakes in a city with high rises. But, to a point,
sloughing brick facades have the same effect...they,
too, are a threat during earthquakes.
Disadvantages

35. • Of the above, the lack of load bearing capability and the
difficulty in working irregular shapes are probably the
biggest disadvantages of using glass in buildings
• Transmits radiant heat; so interiors can gain heat from
outside sources (like the Sun) or lose heat when the
outside is dark. Thus, a steady interior temperature is
harder to maintain unless special technologies are invoked
(like window blinds).
• Privacy from outside viewers would be an issue without
special technologies, like opaque glass.

36. Presented by:
HAFIZ ADIL 2010-IM-17
FAHEEM NAEEM 2010-IM-21
M.UMAIT AKHTAR 2010-IM-18
SUMAIR TARIQ 2010-IM-14