Anodizing Process

The anodizing process increases the durability and lifespan of aluminum. It is an electrochemical conversion process that makes the aluminum surface hard and durable. It prevents the corrosion and oxidation of the metal and stops it from turning white when exposed to the weather. The electrochemical process of anodizing forms a layer of aluminum oxide on the surface which protects the aluminum beneath.  The metal’s surface is then more decorative, hard-wearing, and is prepared to accept dyes, paint primer, or adhesives more readily. 

ProTech Anodizing Process – Step by step

Step 1 : Racking method

There are many different racking methods that can used for the same part and we can help you with deciding with racking method is best for your end user and to be cost effective for you. Our two racking methods are bolt and clamp.

Step 2: Tagging each bar / rack

Before our anodizing process even begins our team makes out a bar/rack specific tag so it is processed with consistency and quality in mind.

Step 3 : Processing the Bar

  1. Each and every bar will be placed into our cleaner tank to get rid of any impurities from the surface of aluminum.
  2. The bar then travels to our cleaner rinse tank before going to our etch process.
  3. (Depending on customer specifications) The bar travels to our Acid or Caustic etch tank to begin the etching process. This process removes surface scratches and mask die lines by attacking the aluminum. The etch of the aluminum surface makes for a matte finish compared to when it was first put into the tank.
  4. The bar travels to our rinse tank to make sure the etch process is off the parts before continuing down the line.
  5. The bar goes into our deox tank to remove all the silica and magnesium as most of these elements are not soluable in the etch tank. These elements must be removed prior to anodize. The next step is to rinse off the deox in our deox rinse tank.
  6. (Depending on customer specifications) The bar travels to the anodize tanks. This process is where the aluminum oxide coating is built onto the aluminum surface to protect it from the environment in which the finished product will be used.
  7. After anodizing, the bar travels to an optional color tank. In this tank, tin is plated into the pores of the aluminum oxide layer. This process creates colors ranging from Champagne to various bronze tones to black.
  8. Sealing the aluminum oxide coating is the next step. During this step, the tank bath has elevated temperatures near boiling and very specific conditions. The seal process hydrates the pores in the aluminum oxide essentially swelling them shut. This step is vital to ensure stain resistance and corrosion protection of anodized coating. The anodized aluminum is then rinsed and moved to a heated rinse tank to help with the drying process once on the production floor.
  9. The bar is now in the unracking department and set to be quality checked for coating thickness, seal quality, and color (clear to black). The finished material is then packed to the customers specifications and ready for shipment.