News Center
Product center
Anodized Aluminum Sheet/Coil
Mirror Aluminum Sheet/Coil
Color Coated Aluminum Sheet/Coil
Compound Aluminum Sheet/Coil
Alloy Aluminum Sheet/Coil
Pure Aluminum Sheet/Coil
Aluminum Profile
Aluminum Roofing Tile
Stainless Steel Sheet/Coil
Online
 
News Center

What is Anodizing?



Anodizing is a simple electrochemical process developed more than 50 years ago that forms a protective coating of aluminum oxide on the surface of the aluminum. The lifetime of the finish is proportional to the thickness of the anodic coating applied.

Aluminum oxide is a hard, durable, weather resistant substance that protects the base metal. The coating may be colored by dyeing or may exhibit bronze tones through diffraction phenomena produced by the coating. The coating grows from the base aluminum metal by this electrochemical process. The coating is integral to the metal and can not peel or flake. The structure of the coating is many small hexagonal pores, which are filled with a "seal" that hydrolyzes these pores to fill them with inert aluminum oxide.

ADVANTAGES OF ANODIZING

  1. In general anodizing is less expensive than painting with the exception of coil painted products.
  2. Anodizing is harder than PVDF. Anodizing is better for aluminum in high traffic areas where the coating is subject to physical abuse and abrasive cleaners.
  3. Anodizing cannot peel off. The coating is actually part of the metal.
  4. Anodizing gives aluminum a deeper, richer metallic appearance than is possible with organic coatings. This is because an anodized coating is translucent, and one can see the base metal underneath the coating. This translucence contributes to color variation problems, but anodizers are doing a much better job of controlling the amount of color variation than in the past. Computerized color matching with quantitative, objective color data is now possible.
  5. Anodizing is unaffected by sunlight. All organic coatings will eventually fail due to exposure to ultra-violet light.

In 1988 the Aluminum Anodizer's Council was formed by a group of anodizers who were concerned that the market was unaware of the benefits of anodizing. The paint manufacturers were comparing excellent paint to poor anodizing. It was no longer common knowledge in the commercial construction industry that there is a difference between good and bad anodizing. Anodizing which is improperly sealed has poor chemical resistance. Brand new anodizing with a thin coating thickness is nearly identical in appearance to an Aluminum Association Class I (very thick!!) anodized finish. Very thin (sub-Class II) anodized coatings are unsuitable for use on exterior curtainwall or metal roofing.

The advantage of a thicker anodic coating is its durability and longer life. The Achilles heel of anodizing is it's chemical resistance. Eventually the surface of an anodic coating may succumb to acidic pollutants in urban environments. Anodized surfaces, like other building components, must be protected from acidic attack during construction.

After many years anodized surfaces may accumulate dirt and stains that look similar to chalking paint. This "chalk" can be removed with a mild detergent combined with an abrasive cleaning technique. A small amount of the anodic coating can actually be removed, leaving behind a renewed anodized finish which can last for another twenty years. This is why anodizers say their product is "renewable". Once an organic coating has failed, the only options are to re-coat the surface with another paint or replace the metal. When an anodized coating appears to have failed, cleaning often results in a renewed appearance.

ANODIZING AND THE ENVIRONMENT

Anodizing appears to be compatible with today's environmental concerns. Though more research needs to be done to determine the total environmental impact of different aluminum finishes, from a finisher's point of view, anodizing does far less damage.
The chemicals from anodizing can be used by municipal waste water treatment facilities. The aluminum sulfate from anodizing plants' effluent actually improves the solids settling efficiency of some waste water treatment plants. Anodizing emits no ozone producing solvents (VOCs), and there are no heavy metals involved in the process.





 

Home  |  About us   |  Products  |  Applications  |  Equipment  |  News  |  Contact us

Copyright ? 2011-2022 Shanghai Solar Tcechnology&Trae Co.Ltd National Hotline: 021-54856488   Fax:021-60917970

Main: aluminum,aluminum coils,aluminum mirror,aluminum panels,brushed aluminum,titanium silver cross pattern aluminum,tin,aluminum hammer

Address: Shanghai Jiading District Jiangqiao Town Park Road four No.229    ICP:09018528    technical supportWebeast