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Extrusion |
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Accelor
Precision has up to 10 aluminum extrusion presses in its facilities.
With our extrusion presses, it allowed us to provide you with some of
the most consistent lead-times in the industry, and on-time delivery
performance. Our range of extrusion press sizes can produce everything
from the most common large extruded profiles, as well as thin-wall
extruded profiles.
Extrusion press selection is determined by the required tolerances,
wall thickness, circle size for each shape, and order quantity.
Maximum circle sizes are directly related to the billet diameter used
for each press. The billet diameter generally equals the maximum
circle size that each extrusion press can produce, although special
tooling may be designed to extrude shapes larger than the billet
diameter.
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A. Facts
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State of art extrusion presses
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10 automated presses from 660ton to 380mm 3800ton
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Current alloys offered: 6061, 6060 and 6063
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Wide variety of tempers can be achieved (T1, T4, T5,
T52, T6)
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Heat controlled ageing chamber
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In-house tool making
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In-house billet casting
B. Process
Extrusion is defined as the process of shaping material, such as
aluminum, by forcing it to flow through a shaped opening in a
die. Extruded material emerges as an elongated piece with the
same profile as the die opening.
The first step is to choose the desired shape and color. Think
of the shape as the die which will be used and the color as the
temper and alloy needed. Next, the billet is inserted into the
holding chamber and pressure is applied to the handle, which
forces billet through the shape.
Press size determines how large of an extrusion can be produced.
Extrusion size is measured by its longest cross-sectional
dimension. The most important factor in the extrusion process is
temperature. Temperature is most critical because it gives
aluminum desired characteristics such as hardness and finish.
The
steps in the extrusion process are as follows:
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1. |
Billets must be heated to approximately 800-925 ¢X F.
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2. |
After a billet reaches the desired temperature, it is
transferred to the loader where a thin film of smut or
lubricant is added to the billet and to the ram.
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3. |
The billet is
transferred to the cradle. |
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4. |
The ram applies
pressure to the dummy block which, in turn, pushes the
billet until it is inside the container.
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5. |
Under pressure the billet is crushed against the die,
becoming shorter and wider until it has full contact with
the container walls. While the aluminum is pushed through
the die, liquid nitrogen flows around some sections of the
die to cool it. This increases the life of the die and
creates an inert atmosphere which keeps oxides from forming
on the shape being extruded. |
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6. |
As a result of the
pressure added to the billet, the soft but solid metal
begins to squeeze through the die opening.
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7. |
As an extrusion
exits the press, the temperature is taken with a True
Temperature Technology (3T) instrument mounted on the press
platen. The 3T records exit temperature of the aluminum
extrusion. The main purpose of knowing the temperature is to
maintain maximum press speeds. The target exit temperature
for an extrusion is dependent upon the alloy. For example,
the target exit temperature for the alloys 6063, 6463,
6063A, and 6101 is 930¢X F (minimum). |
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8. |
Extrusions are pushed out of the die to the leadout table
and the puller, which guides metal down the run-out table
during extrusion. While being pulled, the extrusion is
cooled by a series of fans along the entire length of the
run-out and cooling table. |
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9. |
When the extrusion reaches a desired length, the extrusion
is cut with a profile saw or a shear. |
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10. |
Metal is transferred (via belt or walking beams systems)
from the run-out table to the cooling table. |
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11. |
After the aluminum has cooled and moved along the cooling
table, it is then moved to the stretcher. Stretching
straightens the extrusions and performs 'work hardening'
(molecular re-alignment which gives aluminum increased
hardness and improved strength). |
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12. |
The next step is
sawing. After extrusions have been stretched they are
transferred to a saw table and cut to specific lengths.
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