2. materials that are composed of inorganic substances …
Traditional Ceramic
Advanced Ceramic
includes clay products, silicate glass and cement.
It consist of carbides (SiC), pure oxides (Al2O3),
nitrides (Si3N4), non-silicate glasses and many others.
Ceramic
3. Porcelain is non-porous vitrified materials
The color of the fired product is usually near to white
porcelain composition consists of:
Quartz (Silica),Feldspar (Flux) and Clay in the ratio of 50: 25: 25
respectively.
5. BALL MILLING
The raw materials required for manufacturing the insulators are:
Quartz
Feldspar(stone powder)
Pyrophillite
Water
River pebbles
Felsites
Alumina clay
6. VIBROSCREENING – SEPERATION/DEMAGNITIZATION
the slip is transferred to the tank from the ball mill
removing the unwanted materials:
like threads of the plastic bags , wooden pieces
Then the mixture is fed to Ferro Filter for removing the iron
particles
. Finally the fresh slip is collected in the fresh tank or storage
tank.
7. FILTER PRESSING – DEWATERING
It is dewatering process
80% of the water is removed from the slip
the slip converts into cake form using nylon clothes
high pressure is applied by compressing them from both sides
Pugging:
It is a de-airing operation under vacuum
in this process the moisture content is reduced up to 22%.
The product which comes out after pugging process is called
as blanks
8. Jiggering – Forming Of Disc Insulators
Pre-shaping blanks are placed into Moulds
The Die and the mould, a mixture of Kerosene oil and
Coconut oil is used as Lubricant.
9. Drying: Chain Dryer:
Insulator after forming are dried In Chain Dryers at 30 to 35 o
c
for about 2 to 3 hours
the insulators will be having less than 15% moisture.
Mould Releasing of Disc Insulators:
Insulators are separated from moulds over Aluminum Ring
Insulator are loaded gently to the Racks
Finishing & Oil Inspection:
finishing operation gives a perfect shape for the product
visual and oil inspection is carried out for the quality of the
product.
10. Glazing
give the required color to the insulators
such as red, brown, black and white
a coating of 0.3mm to 0.5mm of thickness
FIRING OF DISC INSULATOR: -Tunnel kilns
Glazed insulators are loaded to wagons
Fired at temperature at 1235 to1245 o
c in Gas Fired
Tunnel Kilns.
11. TESTING OF INSULATOR:
1. Hydraulic Testing:
200 kg/cm2 pressure is applied at the head portion
2. Thermal Test:
Withstand thermal shock, 70 o
c
Assembly of Metal parts :
The metal parts, cup and pin are joined here
. To join the metal parts there is a special type of cement
known as alkreet cement is used.
12. Final Test:
100% Mechanical Test (At 40% of rated)
High voltage & High Frequency Test
PACKING AND DISPATCH:
insulators are well packed in crates
time taken for all this activities crushing to packing is 31 days
