Seeking Dipping Technologies For Growing Films On Metal Surfaces

We are looking for a technology / concept / product that allows to grow up a film during a dipping / immersion step. Hereby a coating with a high corrosion protection performance shall be uniformly applied to all sections of a complex formed metal workpiece. The applied coating should exhibit a sufficient adherence to the substrate in a subsequent rinsing process. The solution may come from textiles, hair treatment, paper, paints, etc… and which will be considered when the process is adaptable to metal surfaces.

The common immersion / dip coating technologies for treating metallic workpieces exhibit several disadvantages such as the occurrence of varnish tears and runs when using methods based upon the formulation viscosity for adhering the coating on the surfaces. These effects are not present by using the electrophoretic methods, which on the other hand require an expensive, complex infrastructure in combination with a high energy / current consumption, but allow to gain homogeneous, adherent films that are resistant against subsequent rinsing processes. Another disadvantage originates from a design restriction for the workpieces, as box sections cannot be uniformly coated due to the Faradaic cage effect (throwing power). Another concept relies on the pickling attack of the metal surface to generate ions that in succession lead to a coagulation of dispersion particles.

The desired solution consists of a novel immersion / dip coating technology and has the benefit to create a uniform coating on each section of a workpiece; e.g. skin- and box section with same thickness regardless of the used metal or alloy. The film growing in the immersion / dip process should run without electricity and/or metal surface pickling attack. The formed film maintains a sufficient rinse resistance to efficiently eliminate excess material by a subsequent rinsing stage. The whole process should be realized with a low energy consumption, low infrastructural investment costs and exhibits a good robustness.

An immersion / dip coat concept / technology suitable for a diversity of metal substrates exhibiting:

• Multimetal capability (steel, galvanized steel, aluminum)
• Resulting dry film thickness of 3 up to 15 µm on assembled and formed metallic parts
• Resistant against subsequent rinsing processes
• Environmental sustainability
• No or low VOC

Coating deposition mechanisms using:

• electric power (e. g. electrophoretic deposition)
• viscosity effects (e. g. wet films adhere due to high viscosity of the used formulation)
• classical autophoresis based on substrate pickling
• solvent-borne approaches
• plasma deposition techniques (CVD and PVD)

Establish a relationship with a co-development partner or adopt a viable concept / technology / product before end of this year. The complete project will end within 3-5 years.

Innovative solutions that do not fulfill all demands or were developed with different backgrounds will be considered, as long as there is visible potential for a successful adaption to our needs.