Dip coating metal is commonly used for the handles of tools and instruments.

Dip coating is reliable, economical, and protective

As the name suggests, dip coating is a coating process where a metal substrate is immersed or ‘dipped’ into a liquid/fluidised coating and then withdrawn at a controlled speed. A layer of coating is thereby deposited on the substrate, with the rate of deposition and thickness determined by the speed at which the substrate is dipped. It can be used to improve the overall look and protection of the substrate, increase or improve the grip, or to add corrosion protection. Dip coating is used for a variety of coating types and applications across industries, including nano coatings and plastisol.

In this article we look at the plastic dip coating process, its advantages, and its applications. We also direct you to dip coating companies in Canada.


The dip coating process

The dip coating process is relatively simple; a substrate is immersed in and then removed from a liquid coating. It is the details that make it work – how long the substrate is immersed, the speed of immersion and withdrawal, the viscosity of the coating, etc. The stages in dip coating are:

  1. Pretreatment: An important step in any coating application, the pretreatment for dip coating ensures a clean, contamination-free, and prepared substrate that will provide the best surface for the coating to adhere to. This may involve a solvent or phosphate bath, sandblasting, or the application of a primer.
  2. Immersion: The substrate is immersed (dipped) into the coating at a constant speed. The substrate is heated before immersion to enhance adhesion.
  3. Dwelling: The substrate remains fully immersed in the dip coating for a specified period of time.
  4. Withdrawal: The substrate is withdrawn at a constant rate, without any jitters or jolts to allow for a uniform, smooth finish. The faster the withdrawal speed, the thicker the application.
  5. Film formation/drying: The film of the coating is determined by the viscous flow, draining, and the evaporation rate of the solvent.
  6. Curing (optional): Some coatings are cured in an oven rather than allowed to dry.
Metal substrates being coated using the dip coating method.

Metal parts being immersed in a bed of liquid coating.

The benefits of dip plastic coating

Dip coating improves a product by providing a new skin of whatever plastic it is being dipped into. There are numerous advantages to the process:

  • Provides the substrate with corrosion resistance
  • The coating is chemical resistant
  • The new coating can give extra utility and improve handling and appearance
  • Easily variable film thickness
  • Provides thermal and electrical insulation
  • The coating gives the substrate additional resilience and durability

On top of the benefits for the substrate there are other benefits provided by this coating method. It is good for geometrically difficult parts (nooks, crannies, etc), and the excess coating from the parts drips back into the reservoir, allowing for a more efficient use of coating.

For the coating to be effective the parts need sufficient weight to be immersed in the coating, and finish inconsistencies like varying film thicknesses or sags can happen if measures are not taken.

Applications of dip coating across industries

With the benefits mentioned above there are some clear applications for dip coating. Surfaces that need a protective coating from sharp or rough materials, corrosion protection, an improved  appearance or grip, and no seams are many. Hand tools are one of the most common everyday applications. Dip coating is also used in this way for medical instruments, toys, plumbing fittings, exercise equipment and electrical equipment.

Dip coating is also used to obtain thin film coatings for bigger items like metal warehousing racks, stadium seating, wheelchair parts, automotive springs, outdoor street and park furniture, and medical furniture. HVAC components are another important application for dip coating. Blower wheels used in the centrifugal fans are awkwardly shaped but critical to function, so a coating that is able to infiltrate all the crevices is vital.

Plastic dip coating companies in Canada

There are many companies in Canada providing plastic dip coating for a variety of industries. These companies include McCarthy Plastic Coatings Ltd (manufacturer of vinyl dip molded products along with numerous thermo plastic coatings capabilities), Plastico Industries (a-coat, nylon dip, and plastisol dip) and Vinyldip Inc (custom vinyl coatings).

For more information, or to find the right coating applicator for your business project, get in touch! Our experts are here to help. Just use the “Request a Quote” button beneath this article and fill in the contact form to get the balling rolling. We will connect your project with the right coating partner for the job.