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1. WAX INJECTION
Wax replicas of the desired castings are produced
by injection molding. These replicas are called
patterns. |
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2. ASSEMBLY
The patterns are attached to a central wax stick,
called a sprue, to form a casting cluster or assembly. |
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3. SHELL BUILDING
The shell is built by immersing the assembly in
a liquid ceramic slurry and then into a bed of extremely
fine sand. Up to eight layers may be applied in
this manner. |
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4. DEWAX
Once the ceramic is dry, the wax is melted out,
creating a negative impression of the assembly within
the shell. |
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5. CASTING
In the casting, the shell is filled with molten
metal by gravity pouring. As the metal cools, the
parts and gates, sprue and pouring cup become one
solid casting. |
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6. KNOCKOUT
When the metal has cooled and solidified, the ceramic
shell is broken off by vibration or water blasting. |
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7. CUT OFF
The parts are cut away from the central sprue using
a high speed friction saw. |
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8. FINISHED CASTINGS
After minor finishing operations, the metal castings--identical
to the original wax patterns--are ready for shipment
to the customer. |