This Presention is about the chemistry of glass industry. This includes Glass Types of glass General properties of glass Manufacturing process of glass Uses of glass. Pakistan's glass's economy import and export of float glass of Pakistan

2. Presenter:
Muhammad Abubakar
F2019140022
Instructor:
Prof. Dr. Ch. Jamil Anwar
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Contents
1 • What is Glass?
2 • Glass Structure and Properties?
3 • Types?
4 • History?
5 • Raw Material and Chemical Composition?
6 • Manufacturing Process?
7 • Uses?

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What is Glass?
Glass is a hard, brittle substance,
typically transparent or translucent,
made by fusing sand with soda and
lime and cool down. It is used to
make windows, drinking containers,
and other articles.

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What is Glass?
1. Glass is a state of matter. It is a solid produced by
cooling molten material so that the internal
arrangement of atoms, or molecules, remains in a
random or disordered state, similar to the arrangement in
a liquid. Such a solid is said to be amorphous or glassy.
Ordinary solids, by contrast, have regular crystalline
structures.
2. The term "glass" means to most people, however, is a
product made from silica (SiO 2 )

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Structure
Regular Solid Glass

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Properties
1. Amorphous Solid
2. No definite boiling point
3. Very brittle
4. Electrical insulator
5. Soften on heating
6. Can absorb, reflect &
transmit light
7. Soluble in HF
8. Have greater strength
9. Light weight
10.High density
11.Resistant to compression
12.Greater chemical resistance
13.Fire resistant
14.Colour adoptive
15.Low thermal expansion

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Properties
16.High Refractive Index
17.Resistance toward Abrasion
18.No difference in properties
with aging.
19. little light scattering
20.Transparency and Reduced
luminous density
21.Adoptability into sheets,
bulbs and bottles
22.Recycled properties
23.Weather Resistance
24.Does not impart any taste,
smell or colour

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History (Natural Glass)
1. About 5,000 B.C.E , long before human beings had
learned how to make glass, they had used natural
glass to knives, arrowheads, and other useful articles.
2. Commonly natural glass is obsidian, formed when
the heat of volcanoes melts rocks such as granite,
which then become glassy upon cooling.
3. Other natural glasses are pumice, a glassy foam
produced from lava; fulgurites, glass tubes formed
by lightning striking sand or sandy soil; and tektites,
lumps or beads of glass probably formed during
meteoric impacts

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History
4000
B.C.E
• Very small dark-colored beads of
glass have been dated
2500
B.C.E
• These may well have been by-
products of copper smelting or
pottery glazing
1500
B.C.E
• Small pieces of true synthetic glass
appeared in areas such as
Mesopotamia, but an actual glass
industry did not appeared in Egypt.

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Roman cage cup from
the 4th century CE
Ancient Greek glass amphora from
the Hellenistic period.
Glass wears

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Types of Glass
1. Soda Lime Glass
Ancient glasses were based on silica (sand), modified with
various amount of metal oxides, mainly soda (Na2O) and
lime (CaO).
2. Lead glass
In 1664 an Englishman named Ravenscroft found that
adding lead oxide (PbO) to a glass melt produced a brilliant
glass that was much easier to melt and to shape. It has been
used to make fine crystal bowls and goblets and many kinds
of art glass.

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Types of Glass
3. Borosilicate Glass
Contains about 12% boron oxide and can withstand a
temperature variation of 200o C and greater chemical
durability than soda lime glass . Made in early 1900s still
used in laboratory glassware and in kitchen glassware.
4. Alumino-silicate glass
Alumina (Al 2 O 3 ) can be used instead of boron oxide to
achieve even more chemical and temperature resistance It is
used to make the special bottles used for liquid
pharmaceutical prescriptions, and to produce the glass thread
that is woven into fiberglass fabric.

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Types of Glass
5. High silica Glass (fused quartz)
High silica glass (96.5–100% silica) is made for special
purposes for its remarkable durability, excellent
resistance to thermal shock or chemical attack, and
ability to transmit ultraviolet light. Used in Spacecraft
windows can withstand temperatures as high as
1,200 o C.

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Basic
ingredients
Formers
Fluxes
Stabilizers
1. The former used in most glasses
is silica (SiO2)
2. Pure silica is difficult to melt (mp
1,723 o C), fluxes can be added to
lower the melting temperature.
Like include soda (Na2O), potash
(K2O), and lithia (Li2O).
Frequently used fluxes carbonate
substance (Na2CO3)
3. To make glasses stronger
stabilizers are added. The most
common stabilizer is lime (CaO),
but others are magnesia (MgO),
baria (BaO), and litharge (PbO).
Chemical Composition

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Others 1%
SiO2 70-74%
Na2O 12-16%
CaO 5-11%
MgO 1-3%
Al2O3 1-3%

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Raw Materials
Sodium (Na) Na2CO3, Na2SO4 Soft Glass
Potassium (K) Potash, K2CO3, KNO3 Hard Glass
Calcium (Ca) Lime, Lime Stone Glass With High RI
Barium (Bs) BaCO3 Glass With High RI
Lead Litharge, lead Acid Flint Glass
Zinc Zinc Oxide
Heat & Shock Proof
Glass
Borate Borax. Boric Acid
Heat & Shock Proof
Glass
Silica Sand Quartz
Name of Element Source of Element Glass Produced
3.
1.
2.
4.
5.
6.
7.
8.

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Colored Glass
1. Ancients Glasses were
all dark in color, usually
olive green or brown to
jet black.
2. The color was due to the
presence of significant
amounts of metal
impurities
Yellow Ferric Salt
Green Ferrous and
Chromium
Blue Cobalt
Salts

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Manufacturing Process
Melting of Raw Materials
Shaping of Articles
Annealing
Cleaning / Finishing / Polishing

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Melting Process
• Raw material depends upon
variety of Glass.
• Like for Soda Lime Glass Na2O
CaO.SiO2 Sand Mixture, Sodium
Carbonate, Calcium Carbonate in
a ration with raw material as
required for formula a mass is
produced called “ Batch” mixed
with “Cullet” and put into Pot or
Tank furnace (1800°C).

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Regenerative Tank Furnace
• Batch is melted by
Burning Natural
Gases.
• Burning Gases
enter in tank from
one side.
• As regenerative
mean its process as
reversed.

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Understanding by Reactions

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Shaping
•Molten Glass is allowed to cool down a
bit
•Added to molds and shaped articles
•Articles are formed by air blowing
techniques.
•Glass sheets can bee prepared by
pressing molten glass between rollers.

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Molds and Glass Blowing

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ANEELING
• The process of slow and homogeneous cooling of articles made
of glass is known as annealing.
Glass
Cooling
Develop
Strains
Strains
In Inner
side

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FINISHING
• Cleaning
• Grinding
• Polishing
• Cutting
• Enameling
• Grading

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Main fields of Glass Usage
Glass as a building material
Glass for decoratory purposes
Glass for optical purposes
Glass for kitchenware
Glass for Scientific purposes (Labs and instruments)
Glass in automobile and traffic

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Main fields of Glass Usage
Glass in aviation, shipping and space travel.
Glass in Electronics (screens, solar panels)
Communication (fiber optics etc)
Packing and encasing purposes
Mirror or looking glass ( sunlight focusing)

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5,668,517
5,905,832
7,896,202
9,077,523
4,341,296
7,721,870 7,841,825
5,819,508
5,394,970
7,966,161
0
1,000,000
2,000,000
3,000,000
4,000,000
5,000,000
6,000,000
7,000,000
8,000,000
9,000,000
10,000,000
2015 2016 2017 2018 2019
Value
(US$)
Pakistan | Imports and Exports | World | Float glass and surface ground or polished glass, in sheets, whether or
not having an absorbent, reflecting or non-reflecting layer | Value (US$) | 2015 - 2019
Imports Exports

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Thank You
Any Question!