Classification of alumnium finishing

1 To whom is it useful and why?
Finishing aluminum includes a variety of types and methods of surface treatment. Therefore, it is very important for designers and architects to know:
• what types of aluminum finishes are used in industry
• by what signs you need to identify them
• how to choose the right finishing.
To achieve a high level of quality in the finishing of architectural aluminum requires well-coordinated teamwork and cooperation of all participants:
• architect (designer)
• supplier of aluminum products and materials
• a manufacturer of primary aluminum products
• manufacturer of finishing aluminum
• manufacturer of construction works.
The quality of the finishing of aluminum products is not solely the responsibility of either one of them.
Architect:
• must understand the characteristics and limitations of the available aluminum finishes so that he can select those that are appropriate for his purpose. In addition, he must clearly formulate his requirements for the selected type of aluminum finish.
Aluminum supplier and finishing manufacturer:
• must properly interpret the requirements of the architect (designer), apply the correct aluminum alloys and ensure that all technological steps are completed that are necessary to achieve the specified requirements for the finished aluminum product.
Construction contractor:
• must ensure that on-site all products that have a vulnerable finish are handled with due care and, once installed and installed, are adequately protected from damage.
2 Finish aluminum
The main metals used in construction and architecture are aluminum, copper, stainless steel and carbon steel. Compared to other metals, aluminum has the largest variety of possible finishes. Nearly all finishing technologies for copper, stainless steel and carbon steel are applied to aluminum as well, while some are only applied to aluminum.
It should be noted that [1]:
• Most aluminum finishing technologies are not used by primary aluminum manufacturers, but by other specialized manufacturers or manufacturers of finished aluminum products.
• The only type of finish, which is typical only for primary aluminum producers, may be the type of finish “without additional processing”, which corresponds to the English term “as fabricated”.
• At the same time, some primary manufacturers also supply aluminum products with additional finishing, for example, aluminum sheets with organic or laminated coating.
• All other types of finishing are given to aluminum products after they leave their primary equipment: rolling mill, extrusion press or foundry.
3 Classification by the American Aluminum Association
3.1 Structure and notation
The American Aluminum Association (AA) has developed a detailed classification and designation of all industrially used types of aluminum finishes [1, 2].
All aluminum finishes fall into three main categories:
• Technical finishes (M)
• Chemical finishes (C)
• Coatings
The category “Coatings” is further subdivided into subcategories:
• Anodic coatings (A)
• Organic coatings (R)
• Enamel coatings (V)
• Electrolytic and other metal coatings (E)
• Laminated coverings (L).
Each category and subcategory is identified by a separate letter. The letter may be followed by a two-digit number to indicate the various options for this type of finish.
The “X” mark denotes existing and future options for that type of finish or treatment.
Finish designations can be used alone or in conjunction with other designations to establish a complete finishing system.
If only a two-digit letter is used for the designation of the anodic coating, this means that the type of preliminary preparation before anodizing is assigned by the manufacturer of the finish, taking into account the type of product and its end use [1].
3.2 Example of designation of finishing
An example of a typical finish for an interior decorative aluminum panel:
• AA-M42C21A34:
AA: American Aluminum Association;
M42: fine matte, non-directional textured mechanical finish;
C21: fine matt chemical etching
A34: architectural anodizing, class II; electrolytic staining
Finishing manufacturer and customer agree (on samples or in writing) the technology that will be used for the M42 and