What do I need to think about before designing an extrusion?
Choose your Alloy
The properties of your extrusion will vary depending on your choice of alloy, so you need to choose an alloy that will give the appropriate conductivity, strength, resistance to corrosion, weight, durability, and reflectivity you need for your design. Click here to find out more about the weight of various alloys.
Just as importantly, you need to understand the properties of the alloy you choose and the impact they have on extrusion capability – while some alloys might be strong, they can’t necessarily be made into complex shapes. For more information on the types of alloy you could use, click here.
Determine the Thickness of Sides
The easier it is to extrude your design, the less costly the process will be. So it’s better to try and keep the wall thickness of your design constant as it’s easier to extrude. There will be certain situations where you may require varying thicknesses, for example, to guarantee the right strength. These variances can generally be accommodated but they will have an impact on the speed of extrusion and on the final surface finish.
As a general rule, the thickness of the slimmest side should be at least half the thickness of the thickest side.
The more complex a shape is, the more difficult it is to extrude. Wherever you can, try to design simple shapes that are symmetrical with only gradual changes in the thickness of their sides.
You should also think about whether your design needs to be solid or hollow – that can also affect the ease of the extrusion process. In certain situations, hollow shapes are easier to produce than solid ones.
You might also find that it’s more cost-effective to create two or more sections that can be assembled after the extrusion, instead of creating a single, complex extrusion.
Rounded corners are easier to extrude as the aluminium alloy 'flows' through rounded corners much more readily. Where possible, radius all internal and external corners.
Decide on the Finish
Aluminium extrusions can be surface treated to give different aesthetics, considerations should be given to the tolerance range of matings parts if the sections are to be anodised or painted because both of these processes alter the thickness of the profile.
When designing an aluminium extrusion, bear in mind the type of finish you need and provide clear instructions about which sides of the extrusion are the primarily visible surfaces.
Plan the Assembly
Careful consideration should be given to how the extrusions are assembled. The most common types of joints are hinges, screw ports and clip fits (the latter of which are often used to keep costs low). If you would like to know more about the methods you can use to join Aluminium Extrusions, click here.
At this stage it is advisable to have samples produced, as nothing provides more peace-of-mind than a real-world proof of concept. Click here if you are at this stage and would like to look at your sampling options.
Weigh up the Costs
The cost of the final extrusion is a function of its weight and complexity along with the alloy type required. We will advise and quote for a range of design considerations. Tooling for hollow profiles is typically more expensive than solid profiles but still offers great values when compared to alternative production methods.