The last few decades have seen a significant increase in the use of aluminum extrusion. Fields dealing with the product designs and manufacturing are majorly responsible for this surge, and statistics projects using aluminum extrusions will only increase in the near future.
Many people have some basic understanding of this manufacturing process. Below is your exhaustive guide into the world of aluminum extrusions and the right finishes for your perfect finished products.
What is aluminum extrusion?
Aluminum extrusion is a process where aluminum alloy materials are pushed through a die with a calculated cross-sectional profile. The aluminum is pushed by a powerful ram through the die and comes out from the other die opening. When the aluminum is pushed out, it retains the shape of the die.
Essentially, you can think of it as squeezing toothpaste from its tube. Once you press the tube, the toothpaste is ejected at the opening and maintains the shape of the tube’s opening. In this case, the tube is your extrusion die, and the toothpaste represents aluminum.
Can all shapes be extruded?
Generally, there are three main shapes used in aluminum extrusions. These include solid shapes like rods and beams, hollow shapes with one or more voids, and semi-hollow shapes that have a partially closed void.
However, it is worthwhile to mention these are not the only shapes. Since aluminum extrusion has a wide application across diverse industries, some cases may require complex shapes. These shapes can be made directly through extrusion or built independently and joined at the end.
Choosing the right finishes for your aluminum extrusions
After deciding on the design for your custom aluminum extrusion, you’ll need to factor in your finishing options. Finishing services are an integral part of aluminum extrusions. For starters, finishing improves the material’s corrosion resistance which increases the material’s lifespan. The right aluminum extrusion finishing technique can also improve the aesthetic quality of your finished product.
Different finishing types for extruded aluminum
The most common and highly preferred finishes for aluminum extrusions are:
1. Powder coating
This process involves applying organic powder to the metal through electrostatic attraction. The powder is applied to the extruded aluminum before being passed through an oven process for curing. After the curing process, the powder coating morphs into a smooth, hard skin coating the metal.
Powder coating is one of the most used finishing types as it meets the high-performance criteria required in most industries. In addition, this style complies with all the environmental regulations on volatile organic compounds.
2. Anodizing
This is an electrochemical process that transforms the metal surface into a durable, decorative, and corrosion-resistant anodic oxide finish. Aside from adding a natural oxide film, the process increases the durability of your material. This process can also be used where the end material requires the use of vibrant colors.
3. Bright dipping
This method is largely used in cases where the end product needs a shiny glow or luster. The electro-brightening process is done on raw aluminum, and harder tempered alloys produce brighter end products.
4. Liquid paint
These are liquid, mastic, or liquifiable compositions that convert into a hardened solid once applied to the extrusion. Paint coatings provide a uniform end product, and their color versatility means they can be sued on almost any type of extruded aluminum product.
5. Wood grain effect
This process is ideal when you want to create an aesthetically pleasing profile using the natural look of wood while maintaining the benefits of aluminum materials. The first step in this process is applying a base coat of the powder and wrapping the material with a thin patterned film.
The profile then undergoes sublimation, which transfers the patterns directly onto the aluminum extrusion.
6. Mechanical finishes
This is arguably the most used fishing method. It can include buffing, blasting, polishing, grinding, hammering, or pinning the profile. You can achieve different textures using mechanical finishing. This method is also used alongside chemical finishes to end up with improved surface quality.
7. Electrophoresis
Also known as electro-coating, electro-phoretic coating, or e-coating, this process includes immersing parts in a paint solution based in an electrified tank. After immersion, the paint moves to the surface of the profile and securely attaches itself.
As evidenced above, there are several finishing types to choose from. The type you choose largely depends on preference, the intended use of the final product, and the aesthetic appeal of the finished product. If you’re unsure about the best finishing type, you can consult an expert in the field.
