Anodic dip coating (ADC)

Anodic dip coating (ADC) is an electrochemical coating process. This involves depositing of the coating layer on the anode. The work piece to be coated is connected to the anode of the rectifier. The bonding agents of the paint have an anionic character - they are negatively charged. Since the introduction of cathodic dip coating (CDC) for surface coating in the automobile sector ADC is seldom used any more, apart from a few exceptions. Why? On the one hand, CDC offers significantly better corrosion protection. On the other hand, anodic dip coating has several key disadvantages:

  • Anodic dissolution of the item to be painted as side effect > Inclusion of metal ions in the film and therefore high corrosion susceptibility
  • Formation of acidic polymers > low saponification stability
  • Possibility of loss of bond between phosphate layer and metal during separation