This is my personal experience of visit to Gunj Glass Pvt.Ltd. I explain how the table-ware and sheet products are manufactured & which kind of processes and raw materials are required for this.

1. Insert LOGO
Gunj Glass

2. Adnan Aslam
 B.sc Mechanical Engineering
 HITEC university Taxila, Islamabad Pakistan

3. Gunj Glass Works Limited
Address:
N-5, Hassan Abdal
 Head Office:
A/26 S.I.T.E Area,
Manghopir Road Karachi,
Sindh Pakistan.

4. • Gunj Glass was built in 1987 and its approximate
production rate is 120 tons per day.
• Ali glass was built in 1995 and its approximate
production rate is 80 tons per day.
• Production capacity of whole plants is approximately
200 tons per day.

5. Sheet Glass are manufactured with a thickness from 2
mm to 12mm.
 There are to separate settlements; one for glassware
and the other for glass sheets.

6.  The main raw materials used for glass
manufacturing are:
 Silica Sand ( both washed and unwashed)
 Limestone
 Dolomite
 Soda Ash
 Cobalt and Selenium

8. Silica Sand
A fine white sand and it is
needed because it is very pure and
does not contain other unwanted
chemicals.

9.  Limestone is added to give
durability to the glass.
 Dolomite is added to give
strength to the glass
 Soda ash is added to
decrease the melting point of
Silica sand.

10.  Cobalt and Selenium are used
only for table wear products
 Cobalt gives blue colour to glass
 Selenium gives pink colour to the
glass.
 If both Cobalt and Selenium are
used together they will give green
colour to the glass.

12. FOLLOWING ARE THE STEPS FOR THE MANUFACTURING OF GLASS:
 MELTING
 SHAPING AND FORMING
 ANNEALING
 FINISHING

13. Raw materials are now subjected to melting in furnace.
 TANK FURNACE
 70 ton capacity
 Continuous processes.
 temperatures ranges from 1400 to 1600*c
 Acidic or basic Refractory Bricks

14.  With the combination of “mold” and “ plunger” different
shapes of glasses can be made.
 Approximately “1” mold give 20-25 lakhs pieces and import
from China due to lack of machinery in Pakistan.

15. This is very strong and used in doors and windows.
For this “Edging machine” and “Bending machine”
used. The temperature can be maintained about 650*c.
Cooling take place by ambient Air.

16.  By dropping 1kg of ball at 1m height, glass
can be withstand without any damage.
 Glass passing this test will be able to bear
the 10,000 Psi pressure.

17. Two layers of glass is used for making insulat
ed glass:
Simple glass
Reflective glass
WORLD TRADE CENTRE in Bahria town
is made from insulated glass.

18. To reduce internal stresses, annealing takes place.
 Walls are comparatively thick and cooling will not be even.
 The inner and outer skins of a glass become rigid.
 The still contracting inner portion build up internal stresses.
 Uneven cooling develop substantial stresses in the glass.
 Improperly annealed glass are fragile and high breakage.

19. Production rate depends on product requirement:
 Capacity:
 Maximum 70 ton/day
 Work rate 40 ton
 90-98000 pieces per day

20. It is necessary for any industry that must follow some quality and env
ironment rule of International organization for standardization to sale his produ
ct in international market.
Quality Standards
ISO 9001
Environmental Standards
ISO 14001

21. Main Source:
 WAPDA
Fuels:
 Natural Gas
 E-Gas
 Furnace Oil
 Pet coke plant in going to be installed. Their initial cost is high but later on
its cheaper.

22. No safety for workers
Employees Old-Age Benefits Institution (EOBI)
No facility of Social Security