Rana zia ur rehman Graduate Reseracher at KASIT (Korea Advanced of science & Technology) My Email ID: ranazia517@gmail.com

2. 1) Definition
2) Historical background of Glass
3) Glass making processes
4) Types & Utilization of Glass
5) Consumption of Glass
6) Recycling of Glass
7) Social, environmental and health impacts

3. An amorphous solids. The term
is usually applied to inorganic
solids and not to plastics or other
organics.
Glasses do not have crystalline internal
structure. They usually are hard and
brittle solids
Examples:
borosilicate glass, soda-lime glass, isinglass

4. It is thought to have been first created around
3000 BC, during the bronze age. Egyptian
glass beads date back to about 2500 BC. As
early as 4000 BC glass was used in the Middle
East as a glaze to decorate beads. By 1550 BC,
coloured glass vessels were widespread and
used for cooking and drinking. Glass makes up
around 7% of the average household dustbin.

5.  People have used glass dating back to 5000 B.C
 Ancient Egypt: earliest use of glass, for royalty and
priest as luxuries
 Usually use as containers or for decoration purposes
in human history

7.  Silica sand 72%
 Soda Ash 17%
 Lime 5%
Percentage of Ingredients in Glass
silica sand
soda ash
lime
other ingredients
72%
17%
5%
6%

8. Historical method:
 heating and blowing
 shape the glass
products by hand
 requires high skills & is
time consuming

9. 1. Silica sand, limestone, soda
ash and cullet (recycled
glass or broken glass) are
keep dry and cool in a
batcher house in silos or
compartments
2. Mixing and weighting into
proper proportion
3. Send to furnaces in hoppers
a). operated by natural gas
b). heat the mixture at
1300-1600 degrees Celsius
into soften or molten state
www.glassforever.co.uk/howisglassmade/

10. 4. Molding --- molten glass flows to forming machine to mold into
desire shapes
5. Annealing lehrs --- reheating the glass in an oven
> to ensure even cooling of glass for strengthening of
the products
6. Cooling process --- Cool for 30 min to an hour for safe to
handle.
7. Glass products are then decorated,
inspected again and finally packaged
and shipped to our customers.
glass furnace
cooling systems

11. There are a number of different
types of glass, and it is important to
decide which is most suited for a
particular job.

12. 'Ordinary' sheet glass
 This glass is made by passing
the molten glass through
rollers; this process gives an
almost flat finish but the effects
of the rollers upon the molten
glass makes some distortion
inevitable. The glass can be
used in domestic windows etc.

13. Float glass (plate)
 Float glass gets its name from the method of
production used to manufacture it. The
molten glass is 'floated' onto a bed of molten
tin - this produces a glass which is flat and
distortion free.

14. Energy efficient glass
 Some manufacturers produce float
glass with a special thin coating on
one side which, allows the suns
energy to pass through in one
direction while reducing the thermal
transfer the other way

15. Toughened (Safety glass)
 Toughened glass is produced by applying a
special treatment to ordinary float glass after
it has been cut to size and finished. The
treatment involves heating the glass so that it
begins to soften (about 620 degrees C) and
then rapidly cooling it. This produces a glass
which, if broken, breaks into small pieces
without sharp edges.

16. Laminated glass
 As the name suggests, laminated glass is
made up of a sandwich of two or more sheets
of glass , bonded together by a flexible,
normally transparent material.
 If the glass is cracked or broken, the flexible
material is designed to hold the glass
fragments in place.

17. Practical glass
Industrial glass
Glass of science and
medicine

18.  Containers (jars and
bottles)
 · Flat glass
 Lighting glass
 Tableware (drinking
glasses)
 TV tubes and
screens

19. Three largest consumers:
1. glass packaging (43%)
2. domestic commodities
3. construction industry
National Glass Usage

20.  Recycle of glass is mostly used for packaging
> Recycle process is as fallows:

21. Workers:
 Dangerous & harmful to workers if breakage occurs while
glass holds heated or corrosive, can result in serious
injuries
 Glass making process occurs at high temperature
 Glass can broke easily under pressure, impact or thermal
shock
 Prevention:
wear protective clothing and gloves to
prevent those injuries

22. Environmental degradation:
> Air pollution
> Aquatic Life
> Human Health
> Economy