How Coating Methods Affect Material Handling Basket Performance

There’s more than one way to coat a material handling basket—especially when you’re applying powder coats such as polyester TGIC, halar, nylon, or urethane.

There are a few different ways to apply a powder coat, but two of the most common methods are:

• Electrostatic Fluidized Bed; and
• Hot Flocking

Both of these applications use the same processes and equipment. The biggest difference is the way the parts are treated prior to exposing them to the fluid bed. In the standard electrostatic fluidized bed process, the parts are passed through the fluid bed “cold” or untreated. The hot flocking process involves heating the parts prior to passing them through the fluid bed, typically 500°F (260°C) or hotter depending on the specific powder coat material.

Which Process is Better?

This is the million-dollar question, and the answer is: “it depends.”

The electrostatic fluidized bed process tends to be extremely efficient—applying a very thin but even coating of the powder coat material used. This saves on material and allows for fast processing of parts.

Another advantage of this application method is that it’s easier to coat very fine wire mesh without causing webbing between the wires. This is great for coating parts washing wire baskets with fine wires.

There are some issues with the electrostatic fluid bed, however. The biggest issue for most is that because the coating is so thin, it’s often not suited for immersion applications.

Hot flocking, on the other hand, often allows for a thicker coating on a metal form because the powder coat will melt onto the surface of the part being coated so the coating can build up.

This makes hot-flocked coatings a bit better for immersion applications than electrostatic fluidized bed coatings.

However, getting thin wires up to the right temperature for this process is a bit of a challenge—thin wires have less thermal energy capacity than thicker metal plates do, and will lose their heat quickly. Also, some metal alloys lose heat faster than others at any thickness, making them unsuited for hot flocking.

So, the hot flocking process is often reserved for coating thicker wire forms that can hold their temperature long enough to pass through the fluid bed to get the best coating thickness.

Other Factors That Can Affect a Powder Coating’s Application

Because of the similarities between these two processes, there are some things that can affect them both, including:

• The Design of the Basket. Both of these coating processes pass a basket through a cloud of particles—so the particles can only coat the parts of the basket they can reach. Wire basket designs with narrow pockets or recesses may not allow powder coat particles to reach those spots very easily, causing some of the basket to go uncoated.
• Materials Used in the Basket. Different metal alloys have different characteristics for thermal energy capacity, surface adhesion, etc. that will affect how easily a powder coat will bond to its surface and how thickly that coating can build.
• The Specific Coating Used. There are many powder coats to choose from, and each one will have a slightly different reaction to hot flocking and electrostatic fluidized bed coating methods.

In many cases, it’s best to have a comprehensive understanding of your particular parts finishing process, overall basket design, and parts to be handled before settling on any one coating type and application process.

This is why Marlin Steel’s engineers ask clients to fill out a custom basket questionnaire that highlights key aspects of a process such as the equipment & chemicals used, standard operating temperatures, and operating times.

Quotes for coating thickness, type, and application method may change depending on a specific detail about your process.

Find out what coating and coating application method would work best for your process today!