About Electrostatic Painting
Electrostatic painting using Ransburg #2 equipment is the spray process used to apply paint coatings to metal and other conductive substrates without creating over-spray. Atomized paint particles are positively charged and are drawn to grounded metal objects. Atomization occurs due to centrifugal force and the electrostatic charge rather than air being introduced at the tip. There are other, less efficient electrostatic spray process equipment available that can apply paint at a faster rate. When the project demands, EPR uses a variety of electrostatic and non-electrostatic spray processes to provide the best value finish for our clients.
Benefits of the Electrostatic Process
A 95% or greater transfer efficiency of the coatings minimizes over spray and allows a factory equivalent sprayed finish to be applied on the job site. A variety of OEM equivalent, Low VOC paint coatings can be applied electrostatically, including two-component epoxies, polyurethanes, and fluoro-polymers. These coatings chemically “bake” to provide a durable finish without the use of ovens to “force cure” the paint.
The Electrostatic Spray Process provides uniform film thickness and consistent coating performance. The static charge creates a “wrap around” effect providing improved paint coverage.
Typical Electrostatic Applications:
Aluminum Store Fronts
Canopies / Facias
Electrostatic Liquid Paint vs. Powder Coating
EPR is NOT a powder coating company. There are several myths regarding the benefits of powder coating versus liquid coating materials. When the entire process is compared, liquid paint coatings fair well when compared to powder coating.
Powder coating is not any more durable than liquid coatings. Powder was designed to be a coating system that is easier to apply and to be equivalent to the liquid paints currently available for original equipment manufacturing.
The process materials used in manufacturing powder are hazardous waste.
The surface preparation typically used and required before powder coating can be applied creates a hazardous waste.
A considerable amount of energy is required to heat and melt the powder, then dry the liquid at over 400 degrees for about 15 minutes per load in a batch oven. (Non-metal items can’t be powder coated for this reason) Even more heat and energy is required when using a continuous conveyor process. That’s a lot of energy.
Powder coated products can also be under or over cured. Under curing can lead to a soft, easily marrable and weak coating. Over curing can make the coating brittle.
Tolerances can be affected by building the powder coating material too heavy. Colors are generally limited with powder coaters, unless there are large quantities.
Because powder requires an oven, the coating can only be used in a shop environment and cannot be applied at the job site.
As stated above, several of the 2 component coatings EPR applies, have solvents which are vegetable oil based, a sustainable resource which also helps our US farmers. Once the unused paint is completely cured, it is inert and can be sent to landfill with no hazardous waste being generated.
The typical preparation process used for liquid coatings over previously painted products are hand sanding the surface being painted and cleaning with a citrus-based cleaner made from peel oil, a byproduct of the concentrated citrus juice industry.
The 2 component paints used by EPR don’t require heat to “bake” or cure, so metal or non-metal items can be painted. The chemistry used when both components are mixed allow the paint to cure slightly faster with warmer temperatures (over 75 degrees F), or slightly slower with cooler temperatures (45 – 70 degrees F) and are available in nearly any color or finish. This chemistry makes for a versatile system. Most of these paints can be applied at the job site electrostatically or in an EPR paint shop.
Since the paints EPR typically uses are high solid, low VOC coatings, the amount of paint needed is minimal. Usually a minimum or 1.5 – 2 mils film thickness is required for optimal performance properties, and not affect any tolerances for openings, even with multiple coats.
There have been great strides in making liquid paints more environmentally friendly in recent years, and all of us at EPR hope we have helped clear up some misunderstandings regarding liquid paint versus powder paint coatings.