10 Steps of the Aluminum Extrusion Process

Aluminum is a naturally occurring metal mined from the earth’s crust. It has various applications and is considered to be one of the most essential elements in modern-day life. The truth is that many of the conveniences we enjoy today would not be possible without aluminum, which was not the case some 125 years ago.

To extract aluminum from the earth’s crust, manufacturers use a process called extrusion. The best way to explain the process is to compare it to squeezing toothpaste out of a tube.

On a fundamental level, the aluminum extrusion process is easy to understand once you follow the processes involved carefully. It works by using a powerful ram to push the aluminum material through the die, which then emerges through an opening. When it does, it comes out with the same profile as the die and is pulled out on a long runout table.

The force that is applied during the extrusion process must be highly significant if the process is to work. Without such pressure, curving the metal into the required form would be impossible.

That said, the process typically involves ten crucial steps, which include the following:

1. Laying Down of an Aluminum Round Rod

This involves spreading aluminum rods flat on a shelf, leaving gaps between them. However, one must be careful not to pile up solid aluminum rods. Doing so can lead to increased stress levels on the extrusion machine.

2. Heating the Aluminum Round Rod

When heating the aluminum round bar, you must remember to regulate the temperature properly. The process should also be carried out at room temperature. In most cases, after approximately 3.5h of heating, the temperature will rise to about 400 to 500 degrees Celsius.

Regardless of whether or not the temperature gets too high or too low, it will still directly impact the hardness of the profiles. As a result, the temperature must be strictly regulated during heating and cooling.

3. Heating the Mold

The temperature at which the mold and aluminum rod is heated should be the same. Both of them also have to be kept warm after heating, which is at an average temperature of 400-500 degrees Celsius.

4. Preparation of the Mold

Once the mold and aluminum rods have been heated and insulated, the mold is placed into the extrusion machine, and the whole process can begin.

5. Transferring the Aluminum Round Rod to the Extrusion Machine

After preparing the aluminum rod, the next step will be to place it into the raw material entrance found on the extrusion machine before the actual extrusion process begins. The aluminum extrusion manufacturer can also spread some releasing agents on the extrusion machine to help prevent the ram and billet from getting stuck to each other.

6. Billet Material/Aluminum Rod Extrusion

The next step is to wait for the extruded aluminum profile to come out through the discharge port. Once this is done, you can transfer the aluminum rod to the extrusion machine.

7. Cutting the Extruded Aluminum Profile

At this stage, a tractor is used to drag the extruded aluminum profile into the precisely set saw. It is here where producers will cut it into the required lengths.

8. Straightening of the Extruded Aluminum Profile

Once the cutting is done, the aluminum profile is placed on a leveling table for straightening and stretching. From here, the next thing will be to go to the finished product area product to proceed with the final fixed-length cutting.

9. Heating Treatment

During this phase, the ready aluminum profiles are loaded into the frame. They are then transferred to the heating machine to undergo a heating treatment. The shapes are then kept warm for 2 hours. Once the temperature hits 200 degrees Celsius, they can be released. Heat treatment also increases the plasticity and stretching characteristics of aluminum profiles.

10. Cooling

Once the heating process is done, the last thing will be the cooling process, which can be done through either natural or air cooling. From this point, the alloy is ready for various applications across different industries.

Aluminum extrusion is the process of creating parts using specified cross-sectional profiles. This is achieved by pushing the heated alloy material through a die. The shapes created can be hollow, solid, or semi-hollow. Depending on the specifications, they can also be simple or complex pieces.

The entire extrusion process is fascinating, mainly when you consider the fact that it results in 8-24-foot-long profiles that can be heated, treated, finished, and fabricated based on various customer specifications.