Anaphoresis

The process implemented is electro-depositing of paint and consists of submerging the workpiece in a bath of water-based electrically conducting paint.


Description of the process

 A potential difference is applied between the part and a counter-electrode by connecting the part to the positive pole (anode, hence the name anaphoresis) and the counter-electrode to the negative pole (cathode). The resulting effect is accompanied by the migration of particles of paint in suspension from the cathode to the anode. These are then deposited uniformly on practically the whole area of the part immersed. The operation only lasts for a few minutes in a continuously stirred bath.  The paint is then drained off and polymerized in an oven at a temperature below 120°C.

  • Appearance: tray grey 707
  • Thickness: 4 to 30 µm
  • Surface condition: no impact on roughness
  • Reduction in the fatigue: No impact, or in all cases lower impact than that observed on the CAO, fine SAO or STA.

Substrates

All conductive materials (titanium alloys, aluminium, Inconel, stainless steel, etc.) and for all modes of transformation.

Applications

  • Corrosion resistance.
  • Paint adhesion base.
  • Simplification of protection plans for aircraft (process 3 in 1)
  • Economy before hard anodizing.

Sectors concerned: aeronautical, space, automobile, rail, etc.

Choice criteria - Limitations

Considering the significant thicknesses of the oxides formed in hard anodizing, it may be necessary to consider variations in the dimensions of parts. It is sometimes necessary to grind the coating after anodizing to restore the surface condition

Environmental impact

The paint used is mainly composed of water (80%) and contains less than 5% of organic solvents. Consequently, the presence of an ATEX area is not necessary.

The process used does not contain heavy metals or chlorinated solvents and its VOC level is limited

Consequently, so far there is no threat to the continuation of this process.

Reference systems

EN standard in the course of drafting and validation