Autodeposition Coatings

Autodeposition is an environmentally friendly coating process which takes place when chemical reactions deposit the adhesive on the substrate. Autodeposition has grown and matured as a popular process for rubber-to-metal bonding. Similar to electroplating, the coating thickness of the auto deposited film is time related.

A unique feature of the autodeposition process is the formation of a very uniform film over the entire surface of the work piece, even in difficult to reach areas, this allows the coating dispersion to flow into and around the most complex shapes.

What is the Autodeposition Process?

The autodeposition coating process is quite simple. The mild acid bath liberates a small amount of iron from the steel parts being immersed, causing an immediate surface reaction that releases iron ions. These ions interact with the latex in the solution causing coating deposition on the surface of the steel parts. The newly deposited organic film is adherent yet quite porous. This allows the chemical activators to diffuse rapidly in the film and reach the surface of the metal. The continuous formation of coating provides a film with a high degree of surface protection and corrosion resistance.

Typical autodeposition process sequence.

  1. Alkaline Spray Clean
  2. Alkaline Immersion Clean
  3. Plant Water Rinse
  4. Water Rinse
  5. Autodeposition
  6. Plant water rinse
  7. DI water rinse
  8. Curing oven, low temperature cure