Warning: in order to watch properly this Flash animation you should have downloaded the last version of Flash Player, which is available for free at the www.adobe.com website.

Brightening Process

These stages of the process brightening chemistry: chemical brightening, among the working phases, takes place after the pickling or greasing of the material and before the anodization.
These are the steps followed during the chemical brighning process:

Preparation of material

  • Most of the material that undergoes the treatment of chemical brightening must be pre-treated mechanically, in order to erase the biggest surface imperfections.
    Depending on mechanical processing, the following pre-treatments could be necessary:
    – Glazing chemistry;
    – Alkaline degreasing.

Acid neutralization

  • The material is immersed in a bath of nitric acid to neutralize the basicity of the previous treatments.

Chemical brightening

  • The material is immersed in a tank containing a solution of sulfuric acid, nitric acid and phosphoric acid at about 100° C, the various types of brilliance are a result of the adjustment of the timing of immersion.
  • Entry cab brightening
    Entry cab brightening
  • Immersion in acid
    Immersion in acid

Rinse

  • An important part in the success of the process is the first rinse after brightening; times transition from the brightening tank to the rinse tank should be minimized to ensure a successful product.
  • Rinse: immersion
    Rinse: immersion
  • Rinse: exit from the tank
    Rinse: exit from the tank

Decoppering

  • The material is dipped into a "decoppering" solution to remove the film of aluminum oxide produced during brightening.
  • Decoppering: immersion
    Decoppering: immersion
  • Decoppering: exit from the tank
    Decoppering: exit from the tan

Oxidation

  • Procedure used to form the thickness of the surface of aluminium oxide by immersion in tanks containing a solution of Sulphuric Acid in 19 - 20 deg. C. The material is connected to the positive (anode) generators current (rectifiers).
    The rectifiers are equipped with APC (Anodizing Process Computer), a device supervision and control of process parameters which (through an automatic calculation of surface to anodize), allows the setting of the number of microns of oxide enough to maintain a constant density of the necessary current.
    During this process the APC controls the value of total output current by indicating on a display the data for processing. At the end of the process, moreover, it automatically prints all the parameters previously monitored.

Colour (possible)

  • Inorganic Colour: based on the principle of precipitation of metal compounds (such as potassium permanganate and Cobalt acetate), dissolved in tanks within the pores the use of aluminium.
    Organic Colour: based on the principle of formation of chemical bonds between various kinds of azo dyes dissolved in tanks, and the layer of the aluminum oxide.

Fixing

  • It is the final phase of the process, in order to "fix" the layer of anodic oxid by dipping the material in tanks with demineralized water at a temperature of about 100 deg. C with anti-dust products; during this treatment ("hot fixing") the pores of the anodic oxid are closed.

Dry

  • After the processing material is dried in an oven (dual position, variable temperature). This makes possible the immediate discharge of material from workstations and the subsequent packaging.
  • Drying treatment
    Drying treatment
  • Drying treatment
    Drying treatment

Wash

  • The material, during its brightening process, is continuously washed by immersion in many tanks filled with water, static or running.