Dip coating

Dip coating is a powder coating process that involves immersing, or dipping, a substrate into a solution of coating material at a constant speed. It is an industrial process used to manufacture high-volume products such as coated fabrics or prophylactics as well as for specialized coatings in the biomedical field. Numerous chemical and nanomaterial engineering research processes are used in academic research to study the use of dip coating to create thin film coatings. The dip coating technique can deliver a uniform, high-quality film even on bulky, complex shapes.

The earliest application of dip coating is presumed to have been in candle fabrication. Similar to candle making, modern-day substrate dip coating involves repeating the process, until the coated material is built up, therefore resulting in a relatively thick final object. Dip coating can be performed as a continuous roll-to-roll process for flexible laminar substrates (like fabrics). Conversely, 3D objects can simply be inserted and removed from a coating bath while objects like prophylactics are dipped into the coating.

The dip coating process involves five stages:

• Immersion
• Start-up
• Deposition
• Drainage
• Evaporation

Once the dip coating process is complete, the final product may incorporate both the substrate and the coating or the coating can be peeled off so that the object consists only of the dried or solidified coating (as with prophylactics). See Dip Coating manufacturing process for more information.

Academic research projects study certain nanoparticles used as coating materials through dip coating finishes. The applications involved include: multi-layer sensor coatings, implant functionalization, hydrogels, Sol-Gel nanoparticle coatings, self-assembled monolayers, and layer-by-layer nanoparticle assemblies.