Foil aluminum

An alternative to optical surface refinement of aluminum is the filming. First, the same precautions must be taken as in the case of other metals. However, you may have to consider the specifics of light metal in relation to aluminum foil.

The properties of aluminum differing from other metals

Aluminum can be foiled like any other metal. However, when foliating the special features of light metal must be considered. This concerns some properties of aluminum:

untreated aluminum forms an oxide layer on the surface
Aluminum expands thermally relatively strong under heating
as a result, unsuitable films and adhesives
as well as resulting distinction between painted and unpainted aluminum

Consider the thermal expansion

Of course, aluminum can be foiled. The best way to foil aluminum, which is otherwise coated, so for example painted. Nevertheless, as with the coating of aluminum, the strong thermal expansion during heating must still be taken into account.

Straight outside window profiles are exposed to solar radiation of a greater thermal expansion. This can be further enhanced if the window is without shading on the south side of a building. As with paints you have to make sure that they are suitable for aluminum.

Also consider the UV radiation of external parts

In addition, you also need UV protection when exposing the parts to the sun. Due to the UV irradiation on foiled aluminum window profiles in conjunction with the expansion of the light metal, it can be assumed, especially for low-cost products, that the promised or underlying service life is not reached.

Exclusively high quality films approved for aluminum

So if you are looking for foils to foil aluminum foil, some high-quality car wrapping foils might be the right choice, as they have high resistance. In addition to the thermal expansion and the UV radiation, aluminum may, however, also have something else to consider.

Foiling untreated aluminum (not coated)

Untreated, ie unpainted or otherwise coated aluminum has an oxidation layer. Only the degreasing of aluminum is then not sufficient, since hardly adhere to substances on this oxide layer.

Oxidation layer and conversion layer

However, they must distinguish between the natural oxidation layer and a desired oxide layer, the conversion layer. Also, the conversion layer is an oxidation, but a targeted, in which certain properties such as a rough surface can be adjusted. With a rough surface suitable adhesives adhere to much better.

The oxide layer forms in the air within minutes

In this context, keep in mind that this oxidation layer re-forms immediately after mechanical machining processes in which you remove the old oxide layer. This concerns, for example, the grinding or polishing of aluminum.

Summary for foiling aluminum

From the assembly, the filming is not too different from sticking a film on other metals. However, the film must be suitable for aluminum as well as the adhesive layer. For untreated, uncoated aluminum, it may still be the case that the film does not adhere. For parts that are exposed to solar radiation, you must take into account not only the thermal suitability but also the UV radiation.

Tips & Tricks

When foiling a sharp-edged aluminum profile, it may happen that you need to heat the material. However, be careful not to heat the aluminum too much, as increasing temperature can cause hydrogen to escape from the aluminum. In addition, the adhesive effect may also be unsatisfactory depending on the composition of the aluminum alloy.

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