Sapa has extensive knowledge of all kinds of surface finishing that can be applied to a product, but Anodizing and Lacquering are the most common.
Anodizing
It is based on the electrochemical treatment of profiles, creating an artificial alumina (aluminum oxide) coating, normally between 10 and 25µm thick.
The aluminium is oxidised in a controlled way, applying a protective coating.
This coating, very hard, after treatment becomes impenetrable to most chemical agents, air, and water.
Through chemical and mechanical processes it is possible to obtain several different kinds of finishing and colours:
Satin finishing gives a matt appearance to profiles. It’s the most common finishing due to aesthetic, economic, and functional reasons.
Brushed/Grained Finishing gives a brushed appearance.
Polished Finishing gives a glossy appearance.
In conventional processes, the colours range from natural aluminum (the most used in contemporary architecture) to in a palette ranging from bronze and browns to blacks.
The anodizing of aluminum profiles offers a perfect balance combining these characteristics: diversity of finishing in colour and texture, corrosion protection, material longevity, very low maintenance cost, and easy low cost recycling, using the whole of the scrap.
Besides fashion trends, opting for the use of natural coloured anodized aluminum is an obvious added value for contemporary architecture as it exploits its attributes and has a much reduced environmental impact compared to other surface treatment solutions.
Lacquering
Thermolacquering is a more recent surface treatment process consisting of application within a booth a powder paint (polyester based polymer) which hardens with the application of temperature.
There are no color restrictions. We use RAL, NCS S, and colors specified by the customer. Thermolacquering is by far the most common method for applying color to aluminum profiles.
The main characteristics are:
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Minimum fading and smudging risk;
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The process can be repeated several times;
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Significantly better Impact and abrasion resistance compared to wet coating;
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Good deformability (for example, it can be bent after surface treatment);
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Suitable for external applications – Highly resistant to UV radiation and corrosion.
The finishing options used in architecture allow the following types of lacquering:
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Glossy
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Metalized
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Textured
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Timber effect