colourful bench created by dip coating metal

Dip coating metal is more common than you might think

Dip coating is an efficient method of applying plastic coatings on metal surfaces. Dip coating metal is most often realised with thermoplastic powders which are molten in a fluidised bed, where the objects are dipped and receive a seamless thick film coating. Dip coating metal is a common procedure in coating:

  • Amusement park attractions
  • Consumer goods such as exercise equipment, toys and (hand) tools
  • Medical instruments
  • Industrial components such as pipeline parts

Dip coating metal is convenient when the parts that require coating are small or middle size. It makes no sense to dip coat large surface due to the fact that it would require a huge fluidised bed. Therefore, large surfaces are usually spray coated instead.

6 phases of thermoplastic dip coating process

Thermoplastic coatings provide the substrate with a thick corrosion resistant and insulating film which can be given properties according to the application and project needs. Dip coating metal is done in 6 phases which together result in a plastic coating layer.

dip coating metal in fluidised bed of thermoplastics

Dip coating metal in fluidised bed of thermoplastic powder.

  1. Removing contaminants from the objects
  2. Applying a primer and baking it in a curing oven
  3. Dipping the objects into the fluidised bed; note that the object is still warm from the baking of the primer
  4.  Moving the coated objects to a curing oven to bake the coating
  5. Cooling down the objects before handling them further
  6. Inspecting the finished products, packaging and shipping them

The film thickness is dependent on the immersion time, temperature and the thermoplastic powder used. The higher the temperature and the longer the immersion, the thicker the film.

Advantages of dip coating metal

Dip coating metal with plastic coatings (liquid or powder) is always an efficient way apply coatings. However, it also has other benefits regarding the method and the coating itself.

  • The coating forms a protective corrosion resistant barrier
  • It insulates the surface from heat, cold, stress and electrical currents and is sound damping
  • High volumes can be coated and products can be delivered fast
  •  The product becomes UV resistant and extremely durable
  • Comes in a wide range of thicknesses, colours, textures and hardnesses

Plastic dip coating metal in the UK

Dip coating metal is a process than can be fully automatised and used for large volume production, which makes it beneficial for mass production. However, it is also possible to outsource dip coating to an external plastic coating specialist. Setting up a dip coating line (fluidised bed) is a great investment and requires sufficient facilities to function optimally. Therefore, it is not always convenient to set up a line by oneself; but it is better to outsource.

In the UK the following companies carry out plastic dip coating throughout the country:

  • Booth Wire (Hebble Plastic coatings) | Brighouse, near Leeds,  West Yorkshire
  • Plastic coatings | Kingswinford, near Birmingham, West Midlands

The process of letting metal dip coated

If you decide to let dip coating your metal parts done by an external party, be sure to provide all necessary information in order to receive a quote. In general the process of receiving a quote and starting dip coating metal includes the following steps. Note that the path may vary depending on the applicator.

  • Provide the applicator with samples of the products you want coated
  • Inform about coating specifications and required properties (colour, finish, thickness etc.)
  • You will receive a quote based on the samples and information
  • The applicator test coats the samples and sends them to for inspection
  • If you approve the samples, you can ship the products to the applicators facilities, and the production can start.