Aluminium surface treatment

Aluminum is corrosion resistant by nature. However, to improve corrosion protection and other properties of aluminum, we use different types of surface treatment. With some methods, the following properties can be influenced:

• Color
• Hardness
• Friction
• Electrical insulation
• Surface texture

Our main surface treatment methods for optimizing the aluminum product are anodizing and powder coating. Both types protect the extruded aluminum profile and provide a wide range of color options with varied gloss and excellent durability. We also have Hydro HM-white anodizing which gives a UV-resistant surface with a uniform layer thickness. The surface treatment also often includes pre- and post-methods such as etching, polishing, blasting, grinding and printing.

When surface treatment is required, Hydro has a range of solutions that ultimately strengthen the benefits of aluminum and provide an attractive finish. With a more sustainable, long-lasting product, the need for replacement is reduced, which has positive environmental consequences.

Anodizing

Our most widely used surface treatment method with a comprehensive list of benefits is anodizing. Our internal anodizing lines enable a "one stop shop" with short lead times when you buy your aluminum profiles and components with a quality-assured finish.

Anodizing is a process in which the outer surface of an aluminium profile is converted into aluminium oxide, a ceramic with unique properties, which is used to create a permanent new appearance. With anodizing, the oxide layer on the surface of the aluminium is made during an electrochemical process, the natural aluminium color can be maintained, but a variety of other colors are also available.

Anodizing is one of the oldest and more sustainable surface treatments of aluminium. Some of the main advantages of using anodizing are as follows:

• Easy to recycle (cradle to cradle)
• Easy to reuse (circular economy)
• Aesthetically pleasing, providing a decorative surface with durable colour and gloss
• Corrosion resistant
• Improved wear resistance
• Gives a smooth finish
• Offers surface hardness
• Creates additional durability and is able to recondition
• Has a reflection ability
• Provides electrical insulation
• Significantly reduces the risk of filiform corrosion, chipping, flaking, peeling or chalking
• Provides a specific surface structure
• Anodizing is used as a pre-treatment for powder coating as well, the pre-anodization layer guarantees an extra durable conversion layer for the final coating layer.

Hydro HM-white anodizing

Hydro HM-white is only available in white and can be seen as a complement to color anodizing as this can not be done in white. Hydro HM-white is characterized by a high surface finish and even and fine gloss.

The coloring is done according to the Honnystone method and is a combination of anodizing and varnishing. The paint layer, which is not much thicker than with anodizing, is integrated in the surface, which means very good adhesion and coverage on all sides.

The layer thickness is evenly distributed over the surface, even over sharp corners. The tight dimensional tolerance means that HM-white is especially suitable for details that are to be mounted after the surface treatment, for example with a snap function or hinges. The UV-resistant surface with the very good corrosion and gloss resistance means that HM-white is also suitable for harsh outdoor environments.

Powder Coating

During the powder coating process, a free-flowing dry powder is electrostatically applied to add colour or finish effects. It is then cured via heat treatment or UV lights. The advantages of powder coating lie in the combination matrix of color, function, gloss and corrosion properties.

Some of the key highlights of powder coating include:

• Provides protection against corrosion
• Gives a durable finish that lasts a long time
• Powder-coated surfaces have high chemical and mechanical resistance
• The thickness can be chosen from very thin (approx. 20 )m) to max. 200 .m